Move callback-related code from AccountData to its own class

And update the many references.

synapse/app/_base.py

@@ -58,9 +58,6 @@ from synapse.config._base import format_config_error
 from synapse.config.homeserver import HomeServerConfig
 from synapse.config.server import ListenerConfig, ManholeConfig
 from synapse.crypto import context_factory
-from synapse.events.presence_router import load_legacy_presence_router
-from synapse.events.spamcheck import load_legacy_spam_checkers
-from synapse.events.third_party_rules import load_legacy_third_party_event_rules
 from synapse.handlers.auth import load_legacy_password_auth_providers
 from synapse.http.site import SynapseSite
 from synapse.logging.context import PreserveLoggingContext
@@ -68,6 +65,15 @@ from synapse.logging.opentracing import init_tracer
 from synapse.metrics import install_gc_manager, register_threadpool
 from synapse.metrics.background_process_metrics import wrap_as_background_process
 from synapse.metrics.jemalloc import setup_jemalloc_stats
+from synapse.module_api.callbacks.presence_router_callbacks import (
+    load_legacy_presence_router,
+)
+from synapse.module_api.callbacks.spam_checker_callbacks import (
+    load_legacy_spam_checkers,
+)
+from synapse.module_api.callbacks.third_party_event_rules_callbacks import (
+    load_legacy_third_party_event_rules,
+)
 from synapse.types import ISynapseReactor
 from synapse.util import SYNAPSE_VERSION
 from synapse.util.caches.lrucache import setup_expire_lru_cache_entries

synapse/events/presence_router.py

@@ -12,93 +12,19 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from typing import (
-    TYPE_CHECKING,
-    Any,
-    Awaitable,
-    Callable,
-    Dict,
-    Iterable,
-    List,
-    Optional,
-    Set,
-    TypeVar,
-    Union,
-)
-
-from typing_extensions import ParamSpec
+from typing import TYPE_CHECKING, Dict, Iterable, Set, Union
 
 from twisted.internet.defer import CancelledError
 
 from synapse.api.presence import UserPresenceState
-from synapse.util.async_helpers import delay_cancellation, maybe_awaitable
+from synapse.util.async_helpers import delay_cancellation
 
 if TYPE_CHECKING:
     from synapse.server import HomeServer
 
-GET_USERS_FOR_STATES_CALLBACK = Callable[
-    [Iterable[UserPresenceState]], Awaitable[Dict[str, Set[UserPresenceState]]]
-]
-# This must either return a set of strings or the constant PresenceRouter.ALL_USERS.
-GET_INTERESTED_USERS_CALLBACK = Callable[[str], Awaitable[Union[Set[str], str]]]
-
 logger = logging.getLogger(__name__)
 
 
-P = ParamSpec("P")
-R = TypeVar("R")
-
-
-def load_legacy_presence_router(hs: "HomeServer") -> None:
-    """Wrapper that loads a presence router module configured using the old
-    configuration, and registers the hooks they implement.
-    """
-
-    if hs.config.server.presence_router_module_class is None:
-        return
-
-    module = hs.config.server.presence_router_module_class
-    config = hs.config.server.presence_router_config
-    api = hs.get_module_api()
-
-    presence_router = module(config=config, module_api=api)
-
-    # The known hooks. If a module implements a method which name appears in this set,
-    # we'll want to register it.
-    presence_router_methods = {
-        "get_users_for_states",
-        "get_interested_users",
-    }
-
-    # All methods that the module provides should be async, but this wasn't enforced
-    # in the old module system, so we wrap them if needed
-    def async_wrapper(
-        f: Optional[Callable[P, R]]
-    ) -> Optional[Callable[P, Awaitable[R]]]:
-        # 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
-
-        def run(*args: P.args, **kwargs: P.kwargs) -> Awaitable[R]:
-            # 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 maybe_awaitable(f(*args, **kwargs))
-
-        return run
-
-    # Register the hooks through the module API.
-    hooks: Dict[str, Optional[Callable[..., Any]]] = {
-        hook: async_wrapper(getattr(presence_router, hook, None))
-        for hook in presence_router_methods
-    }
-
-    api.register_presence_router_callbacks(**hooks)
-
-
 class PresenceRouter:
     """
     A module that the homeserver will call upon to help route user presence updates to
@@ -108,30 +34,7 @@ class PresenceRouter:
     ALL_USERS = "ALL"
 
     def __init__(self, hs: "HomeServer"):
-        # Initially there are no callbacks
-        self._get_users_for_states_callbacks: List[GET_USERS_FOR_STATES_CALLBACK] = []
-        self._get_interested_users_callbacks: List[GET_INTERESTED_USERS_CALLBACK] = []
-
-    def register_presence_router_callbacks(
-        self,
-        get_users_for_states: Optional[GET_USERS_FOR_STATES_CALLBACK] = None,
-        get_interested_users: Optional[GET_INTERESTED_USERS_CALLBACK] = None,
-    ) -> None:
-        # PresenceRouter modules are required to implement both of these methods
-        # or neither of them as they are assumed to act in a complementary manner
-        paired_methods = [get_users_for_states, get_interested_users]
-        if paired_methods.count(None) == 1:
-            raise RuntimeError(
-                "PresenceRouter modules must register neither or both of the paired callbacks: "
-                "[get_users_for_states, get_interested_users]"
-            )
-
-        # Append the methods provided to the lists of callbacks
-        if get_users_for_states is not None:
-            self._get_users_for_states_callbacks.append(get_users_for_states)
-
-        if get_interested_users is not None:
-            self._get_interested_users_callbacks.append(get_interested_users)
+        self._module_api_callbacks = hs.get_module_api_callbacks().presence_router
 
     async def get_users_for_states(
         self,
@@ -150,13 +53,13 @@ class PresenceRouter:
         """
 
         # Bail out early if we don't have any callbacks to run.
-        if len(self._get_users_for_states_callbacks) == 0:
+        if len(self._module_api_callbacks.get_users_for_states_callbacks) == 0:
             # Don't include any extra destinations for presence updates
             return {}
 
         users_for_states: Dict[str, Set[UserPresenceState]] = {}
         # run all the callbacks for get_users_for_states and combine the results
-        for callback in self._get_users_for_states_callbacks:
+        for callback in self._module_api_callbacks.get_users_for_states_callbacks:
             try:
                 # Note: result is an object here, because we don't trust modules to
                 # return the types they're supposed to.
@@ -206,13 +109,13 @@ class PresenceRouter:
         """
 
         # Bail out early if we don't have any callbacks to run.
-        if len(self._get_interested_users_callbacks) == 0:
+        if len(self._module_api_callbacks.get_interested_users_callbacks) == 0:
             # Don't report any additional interested users
             return set()
 
         interested_users = set()
         # run all the callbacks for get_interested_users and combine the results
-        for callback in self._get_interested_users_callbacks:
+        for callback in self._module_api_callbacks.get_interested_users_callbacks:
             try:
                 result = await delay_cancellation(callback(user_id))
             except CancelledError:

synapse/events/spamcheck.py

@@ -13,19 +13,8 @@
 # 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,
-)
+from typing import TYPE_CHECKING, Collection, Optional, Tuple, Union
 
 # `Literal` appears with Python 3.8.
 from typing_extensions import Literal
@@ -37,7 +26,7 @@ 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.async_helpers import delay_cancellation
 from synapse.util.metrics import Measure
 
 if TYPE_CHECKING:
@@ -46,338 +35,13 @@ if TYPE_CHECKING:
 
 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
+    def __init__(self, hs: "synapse.server.HomeServer"):
         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)
+        self._module_api_callbacks = hs.get_module_api_callbacks().spam_checker
 
     @trace
     async def check_event_for_spam(
@@ -401,7 +65,7 @@ class SpamChecker:
                 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:
+        for callback in self._module_api_callbacks.check_event_for_spam_callbacks:
             with Measure(
                 self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
             ):
@@ -456,7 +120,9 @@ class SpamChecker:
         Returns:
             True if the event should be silently dropped
         """
-        for callback in self._should_drop_federated_event_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.should_drop_federated_event_callbacks:
             with Measure(
                 self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
             ):
@@ -480,7 +146,7 @@ class SpamChecker:
         Returns:
             NOT_SPAM if the operation is permitted, [Codes, Dict] otherwise.
         """
-        for callback in self._user_may_join_room_callbacks:
+        for callback in self._module_api_callbacks.user_may_join_room_callbacks:
             with Measure(
                 self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
             ):
@@ -521,7 +187,7 @@ class SpamChecker:
         Returns:
             NOT_SPAM if the operation is permitted, Codes otherwise.
         """
-        for callback in self._user_may_invite_callbacks:
+        for callback in self._module_api_callbacks.user_may_invite_callbacks:
             with Measure(
                 self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
             ):
@@ -568,7 +234,7 @@ class SpamChecker:
         Returns:
             NOT_SPAM if the operation is permitted, Codes otherwise.
         """
-        for callback in self._user_may_send_3pid_invite_callbacks:
+        for callback in self._module_api_callbacks.user_may_send_3pid_invite_callbacks:
             with Measure(
                 self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
             ):
@@ -605,7 +271,7 @@ class SpamChecker:
         Args:
             userid: The ID of the user attempting to create a room
         """
-        for callback in self._user_may_create_room_callbacks:
+        for callback in self._module_api_callbacks.user_may_create_room_callbacks:
             with Measure(
                 self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
             ):
@@ -641,7 +307,7 @@ class SpamChecker:
             room_alias: The alias to be created
 
         """
-        for callback in self._user_may_create_room_alias_callbacks:
+        for callback in self._module_api_callbacks.user_may_create_room_alias_callbacks:
             with Measure(
                 self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
             ):
@@ -676,7 +342,7 @@ class SpamChecker:
             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:
+        for callback in self._module_api_callbacks.user_may_publish_room_callbacks:
             with Measure(
                 self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
             ):
@@ -717,7 +383,7 @@ class SpamChecker:
         Returns:
             True if the user is spammy.
         """
-        for callback in self._check_username_for_spam_callbacks:
+        for callback in self._module_api_callbacks.check_username_for_spam_callbacks:
             with Measure(
                 self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
             ):
@@ -751,7 +417,9 @@ class SpamChecker:
             Enum for how the request should be handled
         """
 
-        for callback in self._check_registration_for_spam_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.check_registration_for_spam_callbacks:
             with Measure(
                 self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
             ):
@@ -794,7 +462,7 @@ class SpamChecker:
             file_info: Metadata about the file.
         """
 
-        for callback in self._check_media_file_for_spam_callbacks:
+        for callback in self._module_api_callbacks.check_media_file_for_spam_callbacks:
             with Measure(
                 self.clock, "{}.{}".format(callback.__module__, callback.__qualname__)
             ):

synapse/events/third_party_rules.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from typing import TYPE_CHECKING, Any, Awaitable, Callable, List, Optional, Tuple
+from typing import TYPE_CHECKING, Optional, Tuple
 
 from twisted.internet.defer import CancelledError
 
@@ -21,7 +21,7 @@ from synapse.events import EventBase
 from synapse.events.snapshot import UnpersistedEventContextBase
 from synapse.storage.roommember import ProfileInfo
 from synapse.types import Requester, StateMap
-from synapse.util.async_helpers import delay_cancellation, maybe_awaitable
+from synapse.util.async_helpers import delay_cancellation
 
 if TYPE_CHECKING:
     from synapse.server import HomeServer
@@ -29,117 +29,6 @@ if TYPE_CHECKING:
 logger = logging.getLogger(__name__)
 
 
-CHECK_EVENT_ALLOWED_CALLBACK = Callable[
-    [EventBase, StateMap[EventBase]], Awaitable[Tuple[bool, Optional[dict]]]
-]
-ON_CREATE_ROOM_CALLBACK = Callable[[Requester, dict, bool], Awaitable]
-CHECK_THREEPID_CAN_BE_INVITED_CALLBACK = Callable[
-    [str, str, StateMap[EventBase]], Awaitable[bool]
-]
-CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK = Callable[
-    [str, StateMap[EventBase], str], Awaitable[bool]
-]
-ON_NEW_EVENT_CALLBACK = Callable[[EventBase, StateMap[EventBase]], Awaitable]
-CHECK_CAN_SHUTDOWN_ROOM_CALLBACK = Callable[[str, str], Awaitable[bool]]
-CHECK_CAN_DEACTIVATE_USER_CALLBACK = Callable[[str, bool], Awaitable[bool]]
-ON_PROFILE_UPDATE_CALLBACK = Callable[[str, ProfileInfo, bool, bool], Awaitable]
-ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK = Callable[[str, bool, bool], Awaitable]
-ON_THREEPID_BIND_CALLBACK = Callable[[str, str, str], Awaitable]
-ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK = Callable[[str, str, str], Awaitable]
-ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK = Callable[[str, str, str], Awaitable]
-
-
-def load_legacy_third_party_event_rules(hs: "HomeServer") -> None:
-    """Wrapper that loads a third party event rules module configured using the old
-    configuration, and registers the hooks they implement.
-    """
-    if hs.config.thirdpartyrules.third_party_event_rules is None:
-        return
-
-    module, config = hs.config.thirdpartyrules.third_party_event_rules
-
-    api = hs.get_module_api()
-    third_party_rules = module(config=config, module_api=api)
-
-    # The known hooks. If a module implements a method which name appears in this set,
-    # we'll want to register it.
-    third_party_event_rules_methods = {
-        "check_event_allowed",
-        "on_create_room",
-        "check_threepid_can_be_invited",
-        "check_visibility_can_be_modified",
-    }
-
-    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
-
-        # We return a separate wrapper for these methods because, in order to wrap them
-        # correctly, we need to await its result. Therefore it doesn't make a lot of
-        # sense to make it go through the run() wrapper.
-        if f.__name__ == "check_event_allowed":
-            # We need to wrap check_event_allowed because its old form would return either
-            # a boolean or a dict, but now we want to return the dict separately from the
-            # boolean.
-            async def wrap_check_event_allowed(
-                event: EventBase,
-                state_events: StateMap[EventBase],
-            ) -> Tuple[bool, Optional[dict]]:
-                # 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
-
-                res = await f(event, state_events)
-                if isinstance(res, dict):
-                    return True, res
-                else:
-                    return res, None
-
-            return wrap_check_event_allowed
-
-        if f.__name__ == "on_create_room":
-            # We need to wrap on_create_room because its old form would return a boolean
-            # if the room creation is denied, but now we just want it to raise an
-            # exception.
-            async def wrap_on_create_room(
-                requester: Requester, config: dict, is_requester_admin: bool
-            ) -> None:
-                # 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
-
-                res = await f(requester, config, is_requester_admin)
-                if res is False:
-                    raise SynapseError(
-                        403,
-                        "Room creation forbidden with these parameters",
-                    )
-
-            return wrap_on_create_room
-
-        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 f is not None
-
-            return maybe_awaitable(f(*args, **kwargs))
-
-        return run
-
-    # Register the hooks through the module API.
-    hooks = {
-        hook: async_wrapper(getattr(third_party_rules, hook, None))
-        for hook in third_party_event_rules_methods
-    }
-
-    api.register_third_party_rules_callbacks(**hooks)
-
-
 class ThirdPartyEventRules:
     """Allows server admins to provide a Python module implementing an extra
     set of rules to apply when processing events.
@@ -153,99 +42,9 @@ class ThirdPartyEventRules:
 
         self.store = hs.get_datastores().main
         self._storage_controllers = hs.get_storage_controllers()
-
-        self._check_event_allowed_callbacks: List[CHECK_EVENT_ALLOWED_CALLBACK] = []
-        self._on_create_room_callbacks: List[ON_CREATE_ROOM_CALLBACK] = []
-        self._check_threepid_can_be_invited_callbacks: List[
-            CHECK_THREEPID_CAN_BE_INVITED_CALLBACK
-        ] = []
-        self._check_visibility_can_be_modified_callbacks: List[
-            CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK
-        ] = []
-        self._on_new_event_callbacks: List[ON_NEW_EVENT_CALLBACK] = []
-        self._check_can_shutdown_room_callbacks: List[
-            CHECK_CAN_SHUTDOWN_ROOM_CALLBACK
-        ] = []
-        self._check_can_deactivate_user_callbacks: List[
-            CHECK_CAN_DEACTIVATE_USER_CALLBACK
-        ] = []
-        self._on_profile_update_callbacks: List[ON_PROFILE_UPDATE_CALLBACK] = []
-        self._on_user_deactivation_status_changed_callbacks: List[
-            ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK
-        ] = []
-        self._on_threepid_bind_callbacks: List[ON_THREEPID_BIND_CALLBACK] = []
-        self._on_add_user_third_party_identifier_callbacks: List[
-            ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
-        ] = []
-        self._on_remove_user_third_party_identifier_callbacks: List[
-            ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
-        ] = []
-
-    def register_third_party_rules_callbacks(
-        self,
-        check_event_allowed: Optional[CHECK_EVENT_ALLOWED_CALLBACK] = None,
-        on_create_room: Optional[ON_CREATE_ROOM_CALLBACK] = None,
-        check_threepid_can_be_invited: Optional[
-            CHECK_THREEPID_CAN_BE_INVITED_CALLBACK
-        ] = None,
-        check_visibility_can_be_modified: Optional[
-            CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK
-        ] = None,
-        on_new_event: Optional[ON_NEW_EVENT_CALLBACK] = None,
-        check_can_shutdown_room: Optional[CHECK_CAN_SHUTDOWN_ROOM_CALLBACK] = None,
-        check_can_deactivate_user: Optional[CHECK_CAN_DEACTIVATE_USER_CALLBACK] = None,
-        on_profile_update: Optional[ON_PROFILE_UPDATE_CALLBACK] = None,
-        on_user_deactivation_status_changed: Optional[
-            ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK
-        ] = None,
-        on_threepid_bind: Optional[ON_THREEPID_BIND_CALLBACK] = None,
-        on_add_user_third_party_identifier: Optional[
-            ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
-        ] = None,
-        on_remove_user_third_party_identifier: Optional[
-            ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
-        ] = None,
-    ) -> None:
-        """Register callbacks from modules for each hook."""
-        if check_event_allowed is not None:
-            self._check_event_allowed_callbacks.append(check_event_allowed)
-
-        if on_create_room is not None:
-            self._on_create_room_callbacks.append(on_create_room)
-
-        if check_threepid_can_be_invited is not None:
-            self._check_threepid_can_be_invited_callbacks.append(
-                check_threepid_can_be_invited,
-            )
-
-        if check_visibility_can_be_modified is not None:
-            self._check_visibility_can_be_modified_callbacks.append(
-                check_visibility_can_be_modified,
-            )
-
-        if on_new_event is not None:
-            self._on_new_event_callbacks.append(on_new_event)
-
-        if check_can_shutdown_room is not None:
-            self._check_can_shutdown_room_callbacks.append(check_can_shutdown_room)
-
-        if check_can_deactivate_user is not None:
-            self._check_can_deactivate_user_callbacks.append(check_can_deactivate_user)
-        if on_profile_update is not None:
-            self._on_profile_update_callbacks.append(on_profile_update)
-
-        if on_user_deactivation_status_changed is not None:
-            self._on_user_deactivation_status_changed_callbacks.append(
-                on_user_deactivation_status_changed,
-            )
-
-        if on_threepid_bind is not None:
-            self._on_threepid_bind_callbacks.append(on_threepid_bind)
-
-        if on_add_user_third_party_identifier is not None:
-            self._on_add_user_third_party_identifier_callbacks.append(
-                on_add_user_third_party_identifier
-            )
+        self._module_api_callbacks = (
+            hs.get_module_api_callbacks().third_party_event_rules
+        )
 
     async def check_event_allowed(
         self,
@@ -269,7 +68,7 @@ class ThirdPartyEventRules:
             The result from the ThirdPartyRules module, as above.
         """
         # Bail out early without hitting the store if we don't have any callbacks to run.
-        if len(self._check_event_allowed_callbacks) == 0:
+        if len(self._module_api_callbacks.check_event_allowed_callbacks) == 0:
             return True, None
 
         prev_state_ids = await context.get_prev_state_ids()
@@ -283,7 +82,7 @@ class ThirdPartyEventRules:
         # the hashes and signatures.
         event.freeze()
 
-        for callback in self._check_event_allowed_callbacks:
+        for callback in self._module_api_callbacks.check_event_allowed_callbacks:
             try:
                 res, replacement_data = await delay_cancellation(
                     callback(event, state_events)
@@ -324,7 +123,7 @@ class ThirdPartyEventRules:
             config: The creation config from the client.
             is_requester_admin: If the requester is an admin
         """
-        for callback in self._on_create_room_callbacks:
+        for callback in self._module_api_callbacks.on_create_room_callbacks:
             try:
                 await callback(requester, config, is_requester_admin)
             except Exception as e:
@@ -352,12 +151,14 @@ class ThirdPartyEventRules:
             True if the 3PID can be invited, False if not.
         """
         # Bail out early without hitting the store if we don't have any callbacks to run.
-        if len(self._check_threepid_can_be_invited_callbacks) == 0:
+        if len(self._module_api_callbacks.check_threepid_can_be_invited_callbacks) == 0:
             return True
 
         state_events = await self._get_state_map_for_room(room_id)
 
-        for callback in self._check_threepid_can_be_invited_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.check_threepid_can_be_invited_callbacks:
             try:
                 threepid_can_be_invited = await delay_cancellation(
                     callback(medium, address, state_events)
@@ -385,12 +186,17 @@ class ThirdPartyEventRules:
             True if the room's visibility can be modified, False if not.
         """
         # Bail out early without hitting the store if we don't have any callback
-        if len(self._check_visibility_can_be_modified_callbacks) == 0:
+        if (
+            len(self._module_api_callbacks.check_visibility_can_be_modified_callbacks)
+            == 0
+        ):
             return True
 
         state_events = await self._get_state_map_for_room(room_id)
 
-        for callback in self._check_visibility_can_be_modified_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.check_visibility_can_be_modified_callbacks:
             try:
                 visibility_can_be_modified = await delay_cancellation(
                     callback(room_id, state_events, new_visibility)
@@ -412,13 +218,13 @@ class ThirdPartyEventRules:
             event_id: The ID of the event.
         """
         # Bail out early without hitting the store if we don't have any callbacks
-        if len(self._on_new_event_callbacks) == 0:
+        if len(self._module_api_callbacks.on_new_event_callbacks) == 0:
             return
 
         event = await self.store.get_event(event_id)
         state_events = await self._get_state_map_for_room(event.room_id)
 
-        for callback in self._on_new_event_callbacks:
+        for callback in self._module_api_callbacks.on_new_event_callbacks:
             try:
                 await callback(event, state_events)
             except Exception as e:
@@ -434,7 +240,7 @@ class ThirdPartyEventRules:
             requester: The ID of the user requesting the shutdown.
             room_id: The ID of the room.
         """
-        for callback in self._check_can_shutdown_room_callbacks:
+        for callback in self._module_api_callbacks.check_can_shutdown_room_callbacks:
             try:
                 can_shutdown_room = await delay_cancellation(callback(user_id, room_id))
                 if can_shutdown_room is False:
@@ -459,7 +265,7 @@ class ThirdPartyEventRules:
             requester
             user_id: The ID of the room.
         """
-        for callback in self._check_can_deactivate_user_callbacks:
+        for callback in self._module_api_callbacks.check_can_deactivate_user_callbacks:
             try:
                 can_deactivate_user = await delay_cancellation(
                     callback(user_id, by_admin)
@@ -497,7 +303,7 @@ class ThirdPartyEventRules:
             by_admin: Whether the profile update was performed by a server admin.
             deactivation: Whether this change was made while deactivating the user.
         """
-        for callback in self._on_profile_update_callbacks:
+        for callback in self._module_api_callbacks.on_profile_update_callbacks:
             try:
                 await callback(user_id, new_profile, by_admin, deactivation)
             except Exception as e:
@@ -515,7 +321,9 @@ class ThirdPartyEventRules:
             deactivated: Whether the user is now deactivated.
             by_admin: Whether the deactivation was performed by a server admin.
         """
-        for callback in self._on_user_deactivation_status_changed_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.on_user_deactivation_status_changed_callbacks:
             try:
                 await callback(user_id, deactivated, by_admin)
             except Exception as e:
@@ -538,7 +346,7 @@ class ThirdPartyEventRules:
             medium: the threepid's medium.
             address: the threepid's address.
         """
-        for callback in self._on_threepid_bind_callbacks:
+        for callback in self._module_api_callbacks.on_threepid_bind_callbacks:
             try:
                 await callback(user_id, medium, address)
             except Exception as e:
@@ -557,7 +365,9 @@ class ThirdPartyEventRules:
             medium: The medium of the third-party ID (email, msisdn).
             address: The address of the third-party ID (i.e. an email address).
         """
-        for callback in self._on_add_user_third_party_identifier_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.on_add_user_third_party_identifier_callbacks:
             try:
                 await callback(user_id, medium, address)
             except Exception as e:
@@ -579,7 +389,9 @@ class ThirdPartyEventRules:
             medium: The medium of the third-party ID (email, msisdn).
             address: The address of the third-party ID (i.e. an email address).
         """
-        for callback in self._on_remove_user_third_party_identifier_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.on_remove_user_third_party_identifier_callbacks:
             try:
                 await callback(user_id, medium, address)
             except Exception as e:

synapse/handlers/account_data.py

@@ -14,7 +14,7 @@
 # limitations under the License.
 import logging
 import random
-from typing import TYPE_CHECKING, Awaitable, Callable, List, Optional, Tuple
+from typing import TYPE_CHECKING, List, Optional, Tuple
 
 from synapse.api.constants import AccountDataTypes
 from synapse.replication.http.account_data import (
@@ -33,10 +33,6 @@ if TYPE_CHECKING:
 
 logger = logging.getLogger(__name__)
 
-ON_ACCOUNT_DATA_UPDATED_CALLBACK = Callable[
-    [str, Optional[str], str, JsonDict], Awaitable
-]
-
 
 class AccountDataHandler:
     def __init__(self, hs: "HomeServer"):
@@ -60,16 +56,7 @@ class AccountDataHandler:
         self._remove_tag_client = ReplicationRemoveTagRestServlet.make_client(hs)
         self._account_data_writers = hs.config.worker.writers.account_data
 
-        self._on_account_data_updated_callbacks: List[
-            ON_ACCOUNT_DATA_UPDATED_CALLBACK
-        ] = []
-
-    def register_module_callbacks(
-        self, on_account_data_updated: Optional[ON_ACCOUNT_DATA_UPDATED_CALLBACK] = None
-    ) -> None:
-        """Register callbacks from modules."""
-        if on_account_data_updated is not None:
-            self._on_account_data_updated_callbacks.append(on_account_data_updated)
+        self._module_api_callbacks = hs.get_module_api_callbacks().account_data
 
     async def _notify_modules(
         self,
@@ -92,7 +79,7 @@ class AccountDataHandler:
             account_data_type: The type of the account data.
             content: The content that is now associated with this type.
         """
-        for callback in self._on_account_data_updated_callbacks:
+        for callback in self._module_api_callbacks.on_account_data_updated_callbacks:
             try:
                 await callback(user_id, room_id, account_data_type, content)
             except Exception as e:

synapse/handlers/account_validity.py

@@ -15,9 +15,7 @@
 import email.mime.multipart
 import email.utils
 import logging
-from typing import TYPE_CHECKING, Awaitable, Callable, List, Optional, Tuple
-
-from twisted.web.http import Request
+from typing import TYPE_CHECKING, List, Optional, Tuple
 
 from synapse.api.errors import AuthError, StoreError, SynapseError
 from synapse.metrics.background_process_metrics import wrap_as_background_process
@@ -30,25 +28,17 @@ if TYPE_CHECKING:
 
 logger = logging.getLogger(__name__)
 
-# Types for callbacks to be registered via the module api
-IS_USER_EXPIRED_CALLBACK = Callable[[str], Awaitable[Optional[bool]]]
-ON_USER_REGISTRATION_CALLBACK = Callable[[str], Awaitable]
-# Temporary hooks to allow for a transition from `/_matrix/client` endpoints
-# to `/_synapse/client/account_validity`. See `register_account_validity_callbacks`.
-ON_LEGACY_SEND_MAIL_CALLBACK = Callable[[str], Awaitable]
-ON_LEGACY_RENEW_CALLBACK = Callable[[str], Awaitable[Tuple[bool, bool, int]]]
-ON_LEGACY_ADMIN_REQUEST = Callable[[Request], Awaitable]
-
 
 class AccountValidityHandler:
     def __init__(self, hs: "HomeServer"):
         self.hs = hs
         self.config = hs.config
-        self.store = self.hs.get_datastores().main
-        self.send_email_handler = self.hs.get_send_email_handler()
-        self.clock = self.hs.get_clock()
+        self.store = hs.get_datastores().main
+        self.send_email_handler = hs.get_send_email_handler()
+        self.clock = hs.get_clock()
 
-        self._app_name = self.hs.config.email.email_app_name
+        self._app_name = hs.config.email.email_app_name
+        self._module_api_callbacks = hs.get_module_api_callbacks().account_validity
 
         self._account_validity_enabled = (
             hs.config.account_validity.account_validity_enabled
@@ -78,69 +68,6 @@ class AccountValidityHandler:
             if hs.config.worker.run_background_tasks:
                 self.clock.looping_call(self._send_renewal_emails, 30 * 60 * 1000)
 
-        self._is_user_expired_callbacks: List[IS_USER_EXPIRED_CALLBACK] = []
-        self._on_user_registration_callbacks: List[ON_USER_REGISTRATION_CALLBACK] = []
-        self._on_legacy_send_mail_callback: Optional[
-            ON_LEGACY_SEND_MAIL_CALLBACK
-        ] = None
-        self._on_legacy_renew_callback: Optional[ON_LEGACY_RENEW_CALLBACK] = None
-
-        # The legacy admin requests callback isn't a protected attribute because we need
-        # to access it from the admin servlet, which is outside of this handler.
-        self.on_legacy_admin_request_callback: Optional[ON_LEGACY_ADMIN_REQUEST] = None
-
-    def register_account_validity_callbacks(
-        self,
-        is_user_expired: Optional[IS_USER_EXPIRED_CALLBACK] = None,
-        on_user_registration: Optional[ON_USER_REGISTRATION_CALLBACK] = None,
-        on_legacy_send_mail: Optional[ON_LEGACY_SEND_MAIL_CALLBACK] = None,
-        on_legacy_renew: Optional[ON_LEGACY_RENEW_CALLBACK] = None,
-        on_legacy_admin_request: Optional[ON_LEGACY_ADMIN_REQUEST] = None,
-    ) -> None:
-        """Register callbacks from module for each hook."""
-        if is_user_expired is not None:
-            self._is_user_expired_callbacks.append(is_user_expired)
-
-        if on_user_registration is not None:
-            self._on_user_registration_callbacks.append(on_user_registration)
-
-        # The builtin account validity feature exposes 3 endpoints (send_mail, renew, and
-        # an admin one). As part of moving the feature into a module, we need to change
-        # the path from /_matrix/client/unstable/account_validity/... to
-        # /_synapse/client/account_validity, because:
-        #
-        #   * the feature isn't part of the Matrix spec thus shouldn't live under /_matrix
-        #   * the way we register servlets means that modules can't register resources
-        #     under /_matrix/client
-        #
-        # We need to allow for a transition period between the old and new endpoints
-        # in order to allow for clients to update (and for emails to be processed).
-        #
-        # Once the email-account-validity module is loaded, it will take control of account
-        # validity by moving the rows from our `account_validity` table into its own table.
-        #
-        # Therefore, we need to allow modules (in practice just the one implementing the
-        # email-based account validity) to temporarily hook into the legacy endpoints so we
-        # can route the traffic coming into the old endpoints into the module, which is
-        # why we have the following three temporary hooks.
-        if on_legacy_send_mail is not None:
-            if self._on_legacy_send_mail_callback is not None:
-                raise RuntimeError("Tried to register on_legacy_send_mail twice")
-
-            self._on_legacy_send_mail_callback = on_legacy_send_mail
-
-        if on_legacy_renew is not None:
-            if self._on_legacy_renew_callback is not None:
-                raise RuntimeError("Tried to register on_legacy_renew twice")
-
-            self._on_legacy_renew_callback = on_legacy_renew
-
-        if on_legacy_admin_request is not None:
-            if self.on_legacy_admin_request_callback is not None:
-                raise RuntimeError("Tried to register on_legacy_admin_request twice")
-
-            self.on_legacy_admin_request_callback = on_legacy_admin_request
-
     async def is_user_expired(self, user_id: str) -> bool:
         """Checks if a user has expired against third-party modules.
 
@@ -150,7 +77,7 @@ class AccountValidityHandler:
         Returns:
             Whether the user has expired.
         """
-        for callback in self._is_user_expired_callbacks:
+        for callback in self._module_api_callbacks.is_user_expired_callbacks:
             expired = await delay_cancellation(callback(user_id))
             if expired is not None:
                 return expired
@@ -168,7 +95,7 @@ class AccountValidityHandler:
         Args:
             user_id: The ID of the newly registered user.
         """
-        for callback in self._on_user_registration_callbacks:
+        for callback in self._module_api_callbacks.on_user_registration_callbacks:
             await callback(user_id)
 
     @wrap_as_background_process("send_renewals")
@@ -198,8 +125,8 @@ class AccountValidityHandler:
         """
         # If a module supports sending a renewal email from here, do that, otherwise do
         # the legacy dance.
-        if self._on_legacy_send_mail_callback is not None:
-            await self._on_legacy_send_mail_callback(user_id)
+        if self._module_api_callbacks.on_legacy_send_mail_callback is not None:
+            await self._module_api_callbacks.on_legacy_send_mail_callback(user_id)
             return
 
         if not self._account_validity_renew_by_email_enabled:
@@ -336,8 +263,10 @@ class AccountValidityHandler:
         """
         # If a module supports triggering a renew from here, do that, otherwise do the
         # legacy dance.
-        if self._on_legacy_renew_callback is not None:
-            return await self._on_legacy_renew_callback(renewal_token)
+        if self._module_api_callbacks.on_legacy_renew_callback is not None:
+            return await self._module_api_callbacks.on_legacy_renew_callback(
+                renewal_token
+            )
 
         try:
             (

synapse/handlers/auth.py

@@ -65,6 +65,10 @@ from synapse.http.server import finish_request, respond_with_html
 from synapse.http.site import SynapseRequest
 from synapse.logging.context import defer_to_thread
 from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.module_api.callbacks.password_auth_provider_callbacks import (
+    CHECK_3PID_AUTH_CALLBACK,
+    ON_LOGGED_OUT_CALLBACK,
+)
 from synapse.storage.databases.main.registration import (
     LoginTokenExpired,
     LoginTokenLookupResult,
@@ -1096,7 +1100,7 @@ class AuthHandler:
         return self._password_enabled_for_login and self._password_localdb_enabled
 
     def get_supported_login_types(self) -> Iterable[str]:
-        """Get a the login types supported for the /login API
+        """Get the login types supported for the /login API
 
         By default this is just 'm.login.password' (unless password_enabled is
         False in the config file), but password auth providers can provide
@@ -1999,124 +2003,16 @@ def load_single_legacy_password_auth_provider(
     )
 
 
-CHECK_3PID_AUTH_CALLBACK = Callable[
-    [str, str, str],
-    Awaitable[
-        Optional[Tuple[str, Optional[Callable[["LoginResponse"], Awaitable[None]]]]]
-    ],
-]
-ON_LOGGED_OUT_CALLBACK = Callable[[str, Optional[str], str], Awaitable]
-CHECK_AUTH_CALLBACK = Callable[
-    [str, str, JsonDict],
-    Awaitable[
-        Optional[Tuple[str, Optional[Callable[["LoginResponse"], Awaitable[None]]]]]
-    ],
-]
-GET_USERNAME_FOR_REGISTRATION_CALLBACK = Callable[
-    [JsonDict, JsonDict],
-    Awaitable[Optional[str]],
-]
-GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK = Callable[
-    [JsonDict, JsonDict],
-    Awaitable[Optional[str]],
-]
-IS_3PID_ALLOWED_CALLBACK = Callable[[str, str, bool], Awaitable[bool]]
-
-
 class PasswordAuthProvider:
     """
     A class that the AuthHandler calls when authenticating users
     It allows modules to provide alternative methods for authentication
     """
 
-    def __init__(self) -> None:
-        # lists of callbacks
-        self.check_3pid_auth_callbacks: List[CHECK_3PID_AUTH_CALLBACK] = []
-        self.on_logged_out_callbacks: List[ON_LOGGED_OUT_CALLBACK] = []
-        self.get_username_for_registration_callbacks: List[
-            GET_USERNAME_FOR_REGISTRATION_CALLBACK
-        ] = []
-        self.get_displayname_for_registration_callbacks: List[
-            GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK
-        ] = []
-        self.is_3pid_allowed_callbacks: List[IS_3PID_ALLOWED_CALLBACK] = []
-
-        # Mapping from login type to login parameters
-        self._supported_login_types: Dict[str, Tuple[str, ...]] = {}
-
-        # Mapping from login type to auth checker callbacks
-        self.auth_checker_callbacks: Dict[str, List[CHECK_AUTH_CALLBACK]] = {}
-
-    def register_password_auth_provider_callbacks(
-        self,
-        check_3pid_auth: Optional[CHECK_3PID_AUTH_CALLBACK] = None,
-        on_logged_out: Optional[ON_LOGGED_OUT_CALLBACK] = None,
-        is_3pid_allowed: Optional[IS_3PID_ALLOWED_CALLBACK] = None,
-        auth_checkers: Optional[
-            Dict[Tuple[str, Tuple[str, ...]], CHECK_AUTH_CALLBACK]
-        ] = None,
-        get_username_for_registration: Optional[
-            GET_USERNAME_FOR_REGISTRATION_CALLBACK
-        ] = None,
-        get_displayname_for_registration: Optional[
-            GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK
-        ] = None,
-    ) -> None:
-        # Register check_3pid_auth callback
-        if check_3pid_auth is not None:
-            self.check_3pid_auth_callbacks.append(check_3pid_auth)
-
-        # register on_logged_out callback
-        if on_logged_out is not None:
-            self.on_logged_out_callbacks.append(on_logged_out)
-
-        if auth_checkers is not None:
-            # register a new supported login_type
-            # Iterate through all of the types being registered
-            for (login_type, fields), callback in auth_checkers.items():
-                # Note: fields may be empty here. This would allow a modules auth checker to
-                # be called with just 'login_type' and no password or other secrets
-
-                # Need to check that all the field names are strings or may get nasty errors later
-                for f in fields:
-                    if not isinstance(f, str):
-                        raise RuntimeError(
-                            "A module tried to register support for login type: %s with parameters %s"
-                            " but all parameter names must be strings"
-                            % (login_type, fields)
-                        )
-
-                # 2 modules supporting the same login type must expect the same fields
-                # e.g. 1 can't expect "pass" if the other expects "password"
-                # so throw an exception if that happens
-                if login_type not in self._supported_login_types.get(login_type, []):
-                    self._supported_login_types[login_type] = fields
-                else:
-                    fields_currently_supported = self._supported_login_types.get(
-                        login_type
-                    )
-                    if fields_currently_supported != fields:
-                        raise RuntimeError(
-                            "A module tried to register support for login type: %s with parameters %s"
-                            " but another module had already registered support for that type with parameters %s"
-                            % (login_type, fields, fields_currently_supported)
-                        )
-
-                # Add the new method to the list of auth_checker_callbacks for this login type
-                self.auth_checker_callbacks.setdefault(login_type, []).append(callback)
-
-        if get_username_for_registration is not None:
-            self.get_username_for_registration_callbacks.append(
-                get_username_for_registration,
-            )
-
-        if get_displayname_for_registration is not None:
-            self.get_displayname_for_registration_callbacks.append(
-                get_displayname_for_registration,
-            )
-
-        if is_3pid_allowed is not None:
-            self.is_3pid_allowed_callbacks.append(is_3pid_allowed)
+    def __init__(self, hs: "HomeServer") -> None:
+        self._module_api_callbacks = (
+            hs.get_module_api_callbacks().password_auth_provider
+        )
 
     def get_supported_login_types(self) -> Mapping[str, Iterable[str]]:
         """Get the login types supported by this password provider
@@ -2126,7 +2022,7 @@ class PasswordAuthProvider:
         to the /login API.
         """
 
-        return self._supported_login_types
+        return self._module_api_callbacks.supported_login_types
 
     async def check_auth(
         self, username: str, login_type: str, login_dict: JsonDict
@@ -2149,7 +2045,7 @@ class PasswordAuthProvider:
 
         # Go through all callbacks for the login type until one returns with a value
         # other than None (i.e. until a callback returns a success)
-        for callback in self.auth_checker_callbacks[login_type]:
+        for callback in self._module_api_callbacks.auth_checker_callbacks[login_type]:
             try:
                 result = await delay_cancellation(
                     callback(username, login_type, login_dict)
@@ -2214,7 +2110,7 @@ class PasswordAuthProvider:
         # (user_id, callback_func), where callback_func should be run
         # after we've finished everything else
 
-        for callback in self.check_3pid_auth_callbacks:
+        for callback in self._module_api_callbacks.check_3pid_auth_callbacks:
             try:
                 result = await delay_cancellation(callback(medium, address, password))
             except CancelledError:
@@ -2272,7 +2168,7 @@ class PasswordAuthProvider:
         self, user_id: str, device_id: Optional[str], access_token: str
     ) -> None:
         # call all of the on_logged_out callbacks
-        for callback in self.on_logged_out_callbacks:
+        for callback in self._module_api_callbacks.on_logged_out_callbacks:
             try:
                 await callback(user_id, device_id, access_token)
             except Exception as e:
@@ -2297,7 +2193,9 @@ class PasswordAuthProvider:
             The localpart to use when registering this user, or None if no module
             returned a localpart.
         """
-        for callback in self.get_username_for_registration_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.get_username_for_registration_callbacks:
             try:
                 res = await delay_cancellation(callback(uia_results, params))
 
@@ -2342,7 +2240,9 @@ class PasswordAuthProvider:
             A tuple which first element is the display name, and the second is an MXC URL
             to the user's avatar.
         """
-        for callback in self.get_displayname_for_registration_callbacks:
+        for (
+            callback
+        ) in self._module_api_callbacks.get_displayname_for_registration_callbacks:
             try:
                 res = await delay_cancellation(callback(uia_results, params))
 
@@ -2385,7 +2285,7 @@ class PasswordAuthProvider:
         Returns:
             Whether the 3PID is allowed to be bound on this homeserver
         """
-        for callback in self.is_3pid_allowed_callbacks:
+        for callback in self._module_api_callbacks.is_3pid_allowed_callbacks:
             try:
                 res = await delay_cancellation(callback(medium, address, registration))
 

synapse/module_api/__init__.py

@@ -39,56 +39,9 @@ from twisted.web.resource import Resource
 from synapse.api import errors
 from synapse.api.errors import SynapseError
 from synapse.events import EventBase
-from synapse.events.presence_router import (
-    GET_INTERESTED_USERS_CALLBACK,
-    GET_USERS_FOR_STATES_CALLBACK,
-    PresenceRouter,
-)
-from synapse.events.spamcheck import (
-    CHECK_EVENT_FOR_SPAM_CALLBACK,
-    CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK,
-    CHECK_REGISTRATION_FOR_SPAM_CALLBACK,
-    CHECK_USERNAME_FOR_SPAM_CALLBACK,
-    SHOULD_DROP_FEDERATED_EVENT_CALLBACK,
-    USER_MAY_CREATE_ROOM_ALIAS_CALLBACK,
-    USER_MAY_CREATE_ROOM_CALLBACK,
-    USER_MAY_INVITE_CALLBACK,
-    USER_MAY_JOIN_ROOM_CALLBACK,
-    USER_MAY_PUBLISH_ROOM_CALLBACK,
-    USER_MAY_SEND_3PID_INVITE_CALLBACK,
-    SpamChecker,
-)
-from synapse.events.third_party_rules import (
-    CHECK_CAN_DEACTIVATE_USER_CALLBACK,
-    CHECK_CAN_SHUTDOWN_ROOM_CALLBACK,
-    CHECK_EVENT_ALLOWED_CALLBACK,
-    CHECK_THREEPID_CAN_BE_INVITED_CALLBACK,
-    CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK,
-    ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK,
-    ON_CREATE_ROOM_CALLBACK,
-    ON_NEW_EVENT_CALLBACK,
-    ON_PROFILE_UPDATE_CALLBACK,
-    ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK,
-    ON_THREEPID_BIND_CALLBACK,
-    ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK,
-)
-from synapse.handlers.account_data import ON_ACCOUNT_DATA_UPDATED_CALLBACK
-from synapse.handlers.account_validity import (
-    IS_USER_EXPIRED_CALLBACK,
-    ON_LEGACY_ADMIN_REQUEST,
-    ON_LEGACY_RENEW_CALLBACK,
-    ON_LEGACY_SEND_MAIL_CALLBACK,
-    ON_USER_REGISTRATION_CALLBACK,
-)
-from synapse.handlers.auth import (
-    CHECK_3PID_AUTH_CALLBACK,
-    CHECK_AUTH_CALLBACK,
-    GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK,
-    GET_USERNAME_FOR_REGISTRATION_CALLBACK,
-    IS_3PID_ALLOWED_CALLBACK,
-    ON_LOGGED_OUT_CALLBACK,
-    AuthHandler,
-)
+from synapse.events.presence_router import PresenceRouter
+from synapse.events.spamcheck import SpamChecker
+from synapse.handlers.auth import AuthHandler
 from synapse.handlers.device import DeviceHandler
 from synapse.handlers.push_rules import RuleSpec, check_actions
 from synapse.http.client import SimpleHttpClient
@@ -105,13 +58,62 @@ from synapse.logging.context import (
     run_in_background,
 )
 from synapse.metrics.background_process_metrics import run_as_background_process
-from synapse.rest.client.login import LoginResponse
-from synapse.storage import DataStore
-from synapse.storage.background_updates import (
+from synapse.module_api.callbacks.account_data_callbacks import (
+    ON_ACCOUNT_DATA_UPDATED_CALLBACK,
+)
+from synapse.module_api.callbacks.account_validity_callbacks import (
+    IS_USER_EXPIRED_CALLBACK,
+    ON_LEGACY_ADMIN_REQUEST,
+    ON_LEGACY_RENEW_CALLBACK,
+    ON_LEGACY_SEND_MAIL_CALLBACK,
+    ON_USER_REGISTRATION_CALLBACK,
+)
+from synapse.module_api.callbacks.background_updater_callbacks import (
     DEFAULT_BATCH_SIZE_CALLBACK,
     MIN_BATCH_SIZE_CALLBACK,
     ON_UPDATE_CALLBACK,
 )
+from synapse.module_api.callbacks.password_auth_provider_callbacks import (
+    CHECK_3PID_AUTH_CALLBACK,
+    CHECK_AUTH_CALLBACK,
+    GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK,
+    GET_USERNAME_FOR_REGISTRATION_CALLBACK,
+    IS_3PID_ALLOWED_CALLBACK,
+    ON_LOGGED_OUT_CALLBACK,
+)
+from synapse.module_api.callbacks.presence_router_callbacks import (
+    GET_INTERESTED_USERS_CALLBACK,
+    GET_USERS_FOR_STATES_CALLBACK,
+)
+from synapse.module_api.callbacks.spam_checker_callbacks import (
+    CHECK_EVENT_FOR_SPAM_CALLBACK,
+    CHECK_MEDIA_FILE_FOR_SPAM_CALLBACK,
+    CHECK_REGISTRATION_FOR_SPAM_CALLBACK,
+    CHECK_USERNAME_FOR_SPAM_CALLBACK,
+    SHOULD_DROP_FEDERATED_EVENT_CALLBACK,
+    USER_MAY_CREATE_ROOM_ALIAS_CALLBACK,
+    USER_MAY_CREATE_ROOM_CALLBACK,
+    USER_MAY_INVITE_CALLBACK,
+    USER_MAY_JOIN_ROOM_CALLBACK,
+    USER_MAY_PUBLISH_ROOM_CALLBACK,
+    USER_MAY_SEND_3PID_INVITE_CALLBACK,
+)
+from synapse.module_api.callbacks.third_party_event_rules_callbacks import (
+    CHECK_CAN_DEACTIVATE_USER_CALLBACK,
+    CHECK_CAN_SHUTDOWN_ROOM_CALLBACK,
+    CHECK_EVENT_ALLOWED_CALLBACK,
+    CHECK_THREEPID_CAN_BE_INVITED_CALLBACK,
+    CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK,
+    ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK,
+    ON_CREATE_ROOM_CALLBACK,
+    ON_NEW_EVENT_CALLBACK,
+    ON_PROFILE_UPDATE_CALLBACK,
+    ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK,
+    ON_THREEPID_BIND_CALLBACK,
+    ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK,
+)
+from synapse.rest.client.login import LoginResponse
+from synapse.storage import DataStore
 from synapse.storage.database import DatabasePool, LoggingTransaction
 from synapse.storage.databases.main.roommember import ProfileInfo
 from synapse.types import (
@@ -250,6 +252,7 @@ class ModuleApi:
         self._push_rules_handler = hs.get_push_rules_handler()
         self._device_handler = hs.get_device_handler()
         self.custom_template_dir = hs.config.server.custom_template_directory
+        self._callbacks = hs.get_module_api_callbacks()
 
         try:
             app_name = self._hs.config.email.email_app_name
@@ -270,13 +273,6 @@ class ModuleApi:
         self._public_room_list_manager = PublicRoomListManager(hs)
         self._account_data_manager = AccountDataManager(hs)
 
-        self._spam_checker = hs.get_spam_checker()
-        self._account_validity_handler = hs.get_account_validity_handler()
-        self._third_party_event_rules = hs.get_third_party_event_rules()
-        self._password_auth_provider = hs.get_password_auth_provider()
-        self._presence_router = hs.get_presence_router()
-        self._account_data_handler = hs.get_account_data_handler()
-
     #################################################################################
     # The following methods should only be called during the module's initialisation.
 
@@ -305,7 +301,7 @@ class ModuleApi:
 
         Added in Synapse v1.37.0.
         """
-        return self._spam_checker.register_callbacks(
+        return self._callbacks.spam_checker.register_callbacks(
             check_event_for_spam=check_event_for_spam,
             should_drop_federated_event=should_drop_federated_event,
             user_may_join_room=user_may_join_room,
@@ -332,7 +328,7 @@ class ModuleApi:
 
         Added in Synapse v1.39.0.
         """
-        return self._account_validity_handler.register_account_validity_callbacks(
+        return self._callbacks.account_validity.register_callbacks(
             is_user_expired=is_user_expired,
             on_user_registration=on_user_registration,
             on_legacy_send_mail=on_legacy_send_mail,
@@ -370,7 +366,7 @@ class ModuleApi:
 
         Added in Synapse v1.39.0.
         """
-        return self._third_party_event_rules.register_third_party_rules_callbacks(
+        return self._callbacks.third_party_event_rules.register_callbacks(
             check_event_allowed=check_event_allowed,
             on_create_room=on_create_room,
             check_threepid_can_be_invited=check_threepid_can_be_invited,
@@ -395,7 +391,7 @@ class ModuleApi:
 
         Added in Synapse v1.42.0.
         """
-        return self._presence_router.register_presence_router_callbacks(
+        return self._callbacks.presence_router.register_callbacks(
             get_users_for_states=get_users_for_states,
             get_interested_users=get_interested_users,
         )
@@ -420,7 +416,7 @@ class ModuleApi:
 
         Added in Synapse v1.46.0.
         """
-        return self._password_auth_provider.register_password_auth_provider_callbacks(
+        return self._callbacks.password_auth_provider.register_callbacks(
             check_3pid_auth=check_3pid_auth,
             on_logged_out=on_logged_out,
             is_3pid_allowed=is_3pid_allowed,
@@ -441,12 +437,11 @@ class ModuleApi:
         Added in Synapse v1.49.0.
         """
 
-        for db in self._hs.get_datastores().databases:
-            db.updates.register_update_controller_callbacks(
-                on_update=on_update,
-                default_batch_size=default_batch_size,
-                min_batch_size=min_batch_size,
-            )
+        self._callbacks.background_updater.register_callbacks(
+            on_update=on_update,
+            default_batch_size=default_batch_size,
+            min_batch_size=min_batch_size,
+        )
 
     def register_account_data_callbacks(
         self,
@@ -457,7 +452,7 @@ class ModuleApi:
 
         Added in Synapse 1.57.0.
         """
-        return self._account_data_handler.register_module_callbacks(
+        return self._callbacks.account_data.register_callbacks(
             on_account_data_updated=on_account_data_updated,
         )
 

synapse/module_api/callbacks/__init__.py

@@ -0,0 +1,36 @@
+# Copyright 2023 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.
+
+from .account_data_callbacks import AccountDataModuleApiCallbacks
+from .account_validity_callbacks import AccountValidityModuleApiCallbacks
+from .background_updater_callbacks import BackgroundUpdaterModuleApiCallbacks
+from .password_auth_provider_callbacks import PasswordAuthProviderModuleApiCallbacks
+from .presence_router_callbacks import PresenceRouterModuleApiCallbacks
+from .spam_checker_callbacks import SpamCheckerModuleApiCallbacks
+from .third_party_event_rules_callbacks import ThirdPartyEventRulesModuleApiCallbacks
+
+__all__ = [
+    "ModuleApiCallbacks",
+]
+
+
+class ModuleApiCallbacks:
+    def __init__(self) -> None:
+        self.account_data = AccountDataModuleApiCallbacks()
+        self.account_validity = AccountValidityModuleApiCallbacks()
+        self.background_updater = BackgroundUpdaterModuleApiCallbacks()
+        self.password_auth_provider = PasswordAuthProviderModuleApiCallbacks()
+        self.presence_router = PresenceRouterModuleApiCallbacks()
+        self.spam_checker = SpamCheckerModuleApiCallbacks()
+        self.third_party_event_rules = ThirdPartyEventRulesModuleApiCallbacks()

synapse/module_api/callbacks/account_data_callbacks.py

@@ -0,0 +1,35 @@
+# Copyright 2015, 2016 OpenMarket Ltd
+# Copyright 2021, 2023 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.
+from typing import Awaitable, Callable, List, Optional
+
+from synapse.types import JsonDict
+
+ON_ACCOUNT_DATA_UPDATED_CALLBACK = Callable[
+    [str, Optional[str], str, JsonDict], Awaitable
+]
+
+
+class AccountDataModuleApiCallbacks:
+    def __init__(self) -> None:
+        self.on_account_data_updated_callbacks: List[
+            ON_ACCOUNT_DATA_UPDATED_CALLBACK
+        ] = []
+
+    def register_callbacks(
+        self, on_account_data_updated: Optional[ON_ACCOUNT_DATA_UPDATED_CALLBACK] = None
+    ) -> None:
+        """Register callbacks from modules."""
+        if on_account_data_updated is not None:
+            self.on_account_data_updated_callbacks.append(on_account_data_updated)

synapse/module_api/callbacks/account_validity_callbacks.py

@@ -0,0 +1,93 @@
+# Copyright 2023 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 logging
+from typing import Awaitable, Callable, List, Optional, Tuple
+
+from twisted.web.http import Request
+
+logger = logging.getLogger(__name__)
+
+# Types for callbacks to be registered via the module api
+IS_USER_EXPIRED_CALLBACK = Callable[[str], Awaitable[Optional[bool]]]
+ON_USER_REGISTRATION_CALLBACK = Callable[[str], Awaitable]
+# Temporary hooks to allow for a transition from `/_matrix/client` endpoints
+# to `/_synapse/client/account_validity`. See `register_account_validity_callbacks`.
+ON_LEGACY_SEND_MAIL_CALLBACK = Callable[[str], Awaitable]
+ON_LEGACY_RENEW_CALLBACK = Callable[[str], Awaitable[Tuple[bool, bool, int]]]
+ON_LEGACY_ADMIN_REQUEST = Callable[[Request], Awaitable]
+
+
+class AccountValidityModuleApiCallbacks:
+    def __init__(self) -> None:
+        self.is_user_expired_callbacks: List[IS_USER_EXPIRED_CALLBACK] = []
+        self.on_user_registration_callbacks: List[ON_USER_REGISTRATION_CALLBACK] = []
+        self.on_legacy_send_mail_callback: Optional[ON_LEGACY_SEND_MAIL_CALLBACK] = None
+        self.on_legacy_renew_callback: Optional[ON_LEGACY_RENEW_CALLBACK] = None
+
+        # The legacy admin requests callback isn't a protected attribute because we need
+        # to access it from the admin servlet, which is outside of this handler.
+        self.on_legacy_admin_request_callback: Optional[ON_LEGACY_ADMIN_REQUEST] = None
+
+    def register_callbacks(
+        self,
+        is_user_expired: Optional[IS_USER_EXPIRED_CALLBACK] = None,
+        on_user_registration: Optional[ON_USER_REGISTRATION_CALLBACK] = None,
+        on_legacy_send_mail: Optional[ON_LEGACY_SEND_MAIL_CALLBACK] = None,
+        on_legacy_renew: Optional[ON_LEGACY_RENEW_CALLBACK] = None,
+        on_legacy_admin_request: Optional[ON_LEGACY_ADMIN_REQUEST] = None,
+    ) -> None:
+        """Register callbacks from module for each hook."""
+        if is_user_expired is not None:
+            self.is_user_expired_callbacks.append(is_user_expired)
+
+        if on_user_registration is not None:
+            self.on_user_registration_callbacks.append(on_user_registration)
+
+        # The builtin account validity feature exposes 3 endpoints (send_mail, renew, and
+        # an admin one). As part of moving the feature into a module, we need to change
+        # the path from /_matrix/client/unstable/account_validity/... to
+        # /_synapse/client/account_validity, because:
+        #
+        #   * the feature isn't part of the Matrix spec thus shouldn't live under /_matrix
+        #   * the way we register servlets means that modules can't register resources
+        #     under /_matrix/client
+        #
+        # We need to allow for a transition period between the old and new endpoints
+        # in order to allow for clients to update (and for emails to be processed).
+        #
+        # Once the email-account-validity module is loaded, it will take control of account
+        # validity by moving the rows from our `account_validity` table into its own table.
+        #
+        # Therefore, we need to allow modules (in practice just the one implementing the
+        # email-based account validity) to temporarily hook into the legacy endpoints so we
+        # can route the traffic coming into the old endpoints into the module, which is
+        # why we have the following three temporary hooks.
+        if on_legacy_send_mail is not None:
+            if self.on_legacy_send_mail_callback is not None:
+                raise RuntimeError("Tried to register on_legacy_send_mail twice")
+
+            self.on_legacy_send_mail_callback = on_legacy_send_mail
+
+        if on_legacy_renew is not None:
+            if self.on_legacy_renew_callback is not None:
+                raise RuntimeError("Tried to register on_legacy_renew twice")
+
+            self.on_legacy_renew_callback = on_legacy_renew
+
+        if on_legacy_admin_request is not None:
+            if self.on_legacy_admin_request_callback is not None:
+                raise RuntimeError("Tried to register on_legacy_admin_request twice")
+
+            self.on_legacy_admin_request_callback = on_legacy_admin_request

synapse/module_api/callbacks/background_updater_callbacks.py

@@ -0,0 +1,54 @@
+# Copyright 2014-2016 OpenMarket Ltd
+# Copyright 2023 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 logging
+from typing import AsyncContextManager, Awaitable, Callable, Optional
+
+logger = logging.getLogger(__name__)
+
+ON_UPDATE_CALLBACK = Callable[[str, str, bool], AsyncContextManager[int]]
+DEFAULT_BATCH_SIZE_CALLBACK = Callable[[str, str], Awaitable[int]]
+MIN_BATCH_SIZE_CALLBACK = Callable[[str, str], Awaitable[int]]
+
+
+class BackgroundUpdaterModuleApiCallbacks:
+    def __init__(self) -> None:
+        self.on_update_callback: Optional[ON_UPDATE_CALLBACK] = None
+        self.default_batch_size_callback: Optional[DEFAULT_BATCH_SIZE_CALLBACK] = None
+        self.min_batch_size_callback: Optional[MIN_BATCH_SIZE_CALLBACK] = None
+
+    def register_callbacks(
+        self,
+        on_update: ON_UPDATE_CALLBACK,
+        default_batch_size: Optional[DEFAULT_BATCH_SIZE_CALLBACK] = None,
+        min_batch_size: Optional[DEFAULT_BATCH_SIZE_CALLBACK] = None,
+    ) -> None:
+        """Register callbacks from a module for each hook."""
+        if self.on_update_callback is not None:
+            logger.warning(
+                "More than one module tried to register callbacks for controlling"
+                " background updates. Only the callbacks registered by the first module"
+                " (in order of appearance in Synapse's configuration file) that tried to"
+                " do so will be called."
+            )
+
+            return
+
+        self.on_update_callback = on_update
+
+        if default_batch_size is not None:
+            self.default_batch_size_callback = default_batch_size
+
+        if min_batch_size is not None:
+            self.min_batch_size_callback = min_batch_size

synapse/module_api/callbacks/password_auth_provider_callbacks.py

@@ -0,0 +1,138 @@
+# Copyright 2014 - 2016 OpenMarket Ltd
+# Copyright 2017 Vector Creations Ltd
+# Copyright 2019 - 2020, 2023 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 logging
+from typing import TYPE_CHECKING, Awaitable, Callable, Dict, List, Optional, Tuple
+
+from synapse.types import JsonDict
+
+if TYPE_CHECKING:
+    from synapse.module_api import LoginResponse
+
+logger = logging.getLogger(__name__)
+
+
+CHECK_3PID_AUTH_CALLBACK = Callable[
+    [str, str, str],
+    Awaitable[
+        Optional[Tuple[str, Optional[Callable[["LoginResponse"], Awaitable[None]]]]]
+    ],
+]
+ON_LOGGED_OUT_CALLBACK = Callable[[str, Optional[str], str], Awaitable]
+CHECK_AUTH_CALLBACK = Callable[
+    [str, str, JsonDict],
+    Awaitable[
+        Optional[Tuple[str, Optional[Callable[["LoginResponse"], Awaitable[None]]]]]
+    ],
+]
+GET_USERNAME_FOR_REGISTRATION_CALLBACK = Callable[
+    [JsonDict, JsonDict],
+    Awaitable[Optional[str]],
+]
+GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK = Callable[
+    [JsonDict, JsonDict],
+    Awaitable[Optional[str]],
+]
+IS_3PID_ALLOWED_CALLBACK = Callable[[str, str, bool], Awaitable[bool]]
+
+
+class PasswordAuthProviderModuleApiCallbacks:
+    def __init__(self) -> None:
+        # Mapping from login type to login parameters
+        self.supported_login_types: Dict[str, Tuple[str, ...]] = {}
+
+        self.check_3pid_auth_callbacks: List[CHECK_3PID_AUTH_CALLBACK] = []
+        self.on_logged_out_callbacks: List[ON_LOGGED_OUT_CALLBACK] = []
+        self.get_username_for_registration_callbacks: List[
+            GET_USERNAME_FOR_REGISTRATION_CALLBACK
+        ] = []
+        self.get_displayname_for_registration_callbacks: List[
+            GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK
+        ] = []
+        self.is_3pid_allowed_callbacks: List[IS_3PID_ALLOWED_CALLBACK] = []
+
+        # Mapping from login type to auth checker callbacks
+        self.auth_checker_callbacks: Dict[str, List[CHECK_AUTH_CALLBACK]] = {}
+
+    def register_callbacks(
+        self,
+        check_3pid_auth: Optional[CHECK_3PID_AUTH_CALLBACK] = None,
+        on_logged_out: Optional[ON_LOGGED_OUT_CALLBACK] = None,
+        is_3pid_allowed: Optional[IS_3PID_ALLOWED_CALLBACK] = None,
+        auth_checkers: Optional[
+            Dict[Tuple[str, Tuple[str, ...]], CHECK_AUTH_CALLBACK]
+        ] = None,
+        get_username_for_registration: Optional[
+            GET_USERNAME_FOR_REGISTRATION_CALLBACK
+        ] = None,
+        get_displayname_for_registration: Optional[
+            GET_DISPLAYNAME_FOR_REGISTRATION_CALLBACK
+        ] = None,
+    ) -> None:
+        # Register check_3pid_auth callback
+        if check_3pid_auth is not None:
+            self.check_3pid_auth_callbacks.append(check_3pid_auth)
+
+        # register on_logged_out callback
+        if on_logged_out is not None:
+            self.on_logged_out_callbacks.append(on_logged_out)
+
+        if auth_checkers is not None:
+            # register a new supported login_type
+            # Iterate through all of the types being registered
+            for (login_type, fields), callback in auth_checkers.items():
+                # Note: fields may be empty here. This would allow a modules auth checker to
+                # be called with just 'login_type' and no password or other secrets
+
+                # Need to check that all the field names are strings or may get nasty errors later
+                for f in fields:
+                    if not isinstance(f, str):
+                        raise RuntimeError(
+                            "A module tried to register support for login type: %s with parameters %s"
+                            " but all parameter names must be strings"
+                            % (login_type, fields)
+                        )
+
+                # 2 modules supporting the same login type must expect the same fields
+                # e.g. 1 can't expect "pass" if the other expects "password"
+                # so throw an exception if that happens
+                if login_type not in self.supported_login_types.get(login_type, []):
+                    self.supported_login_types[login_type] = fields
+                else:
+                    fields_currently_supported = self.supported_login_types.get(
+                        login_type
+                    )
+                    if fields_currently_supported != fields:
+                        raise RuntimeError(
+                            "A module tried to register support for login type: %s with parameters %s"
+                            " but another module had already registered support for that type with parameters %s"
+                            % (login_type, fields, fields_currently_supported)
+                        )
+
+                # Add the new method to the list of auth_checker_callbacks for this login type
+                self.auth_checker_callbacks.setdefault(login_type, []).append(callback)
+
+        if get_username_for_registration is not None:
+            self.get_username_for_registration_callbacks.append(
+                get_username_for_registration,
+            )
+
+        if get_displayname_for_registration is not None:
+            self.get_displayname_for_registration_callbacks.append(
+                get_displayname_for_registration,
+            )
+
+        if is_3pid_allowed is not None:
+            self.is_3pid_allowed_callbacks.append(is_3pid_allowed)

synapse/module_api/callbacks/presence_router_callbacks.py

@@ -0,0 +1,122 @@
+# Copyright 2021, 2023 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.
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Awaitable,
+    Callable,
+    Dict,
+    Iterable,
+    List,
+    Optional,
+    Set,
+    TypeVar,
+    Union,
+)
+
+from typing_extensions import ParamSpec
+
+from synapse.api.presence import UserPresenceState
+from synapse.util.async_helpers import maybe_awaitable
+
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
+
+GET_USERS_FOR_STATES_CALLBACK = Callable[
+    [Iterable[UserPresenceState]], Awaitable[Dict[str, Set[UserPresenceState]]]
+]
+# This must either return a set of strings or the constant PresenceRouter.ALL_USERS.
+GET_INTERESTED_USERS_CALLBACK = Callable[[str], Awaitable[Union[Set[str], str]]]
+
+
+P = ParamSpec("P")
+R = TypeVar("R")
+
+
+def load_legacy_presence_router(hs: "HomeServer") -> None:
+    """Wrapper that loads a presence router module configured using the old
+    configuration, and registers the hooks they implement.
+    """
+
+    if hs.config.server.presence_router_module_class is None:
+        return
+
+    module = hs.config.server.presence_router_module_class
+    config = hs.config.server.presence_router_config
+    api = hs.get_module_api()
+
+    presence_router = module(config=config, module_api=api)
+
+    # The known hooks. If a module implements a method which name appears in this set,
+    # we'll want to register it.
+    presence_router_methods = {
+        "get_users_for_states",
+        "get_interested_users",
+    }
+
+    # All methods that the module provides should be async, but this wasn't enforced
+    # in the old module system, so we wrap them if needed
+    def async_wrapper(
+        f: Optional[Callable[P, R]]
+    ) -> Optional[Callable[P, Awaitable[R]]]:
+        # 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
+
+        def run(*args: P.args, **kwargs: P.kwargs) -> Awaitable[R]:
+            # 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 maybe_awaitable(f(*args, **kwargs))
+
+        return run
+
+    # Register the hooks through the module API.
+    hooks: Dict[str, Optional[Callable[..., Any]]] = {
+        hook: async_wrapper(getattr(presence_router, hook, None))
+        for hook in presence_router_methods
+    }
+
+    api.register_presence_router_callbacks(**hooks)
+
+
+class PresenceRouterModuleApiCallbacks:
+    def __init__(self) -> None:
+        # Initially there are no callbacks
+        self.get_users_for_states_callbacks: List[GET_USERS_FOR_STATES_CALLBACK] = []
+        self.get_interested_users_callbacks: List[GET_INTERESTED_USERS_CALLBACK] = []
+
+    def register_callbacks(
+        self,
+        get_users_for_states: Optional[GET_USERS_FOR_STATES_CALLBACK] = None,
+        get_interested_users: Optional[GET_INTERESTED_USERS_CALLBACK] = None,
+    ) -> None:
+        # PresenceRouter modules are required to implement both of these methods
+        # or neither of them as they are assumed to act in a complementary manner
+        paired_methods = [get_users_for_states, get_interested_users]
+        if paired_methods.count(None) == 1:
+            raise RuntimeError(
+                "PresenceRouter modules must register neither or both of the paired callbacks: "
+                "[get_users_for_states, get_interested_users]"
+            )
+
+        # Append the methods provided to the lists of callbacks
+        if get_users_for_states is not None:
+            self.get_users_for_states_callbacks.append(get_users_for_states)
+
+        if get_interested_users is not None:
+            self.get_interested_users_callbacks.append(get_interested_users)

synapse/module_api/callbacks/spam_checker_callbacks.py

@@ -0,0 +1,373 @@
+# Copyright 2017 New Vector Ltd
+# Copyright 2019, 2023 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.rest.media.v1._base import FileInfo
+from synapse.rest.media.v1.media_storage import ReadableFileWrapper
+from synapse.spam_checker_api import RegistrationBehaviour
+from synapse.types import JsonDict, RoomAlias, UserProfile
+from synapse.util.async_helpers import maybe_awaitable
+
+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 SpamCheckerModuleApiCallbacks:
+    def __init__(self) -> None:
+        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)

synapse/module_api/callbacks/third_party_event_rules_callbacks.py

@@ -0,0 +1,238 @@
+# Copyright 2019, 2023 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 logging
+from typing import TYPE_CHECKING, Any, Awaitable, Callable, List, Optional, Tuple
+
+from synapse.api.errors import SynapseError
+from synapse.events import EventBase
+from synapse.storage.roommember import ProfileInfo
+from synapse.types import Requester, StateMap
+from synapse.util.async_helpers import maybe_awaitable
+
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
+
+logger = logging.getLogger(__name__)
+
+CHECK_EVENT_ALLOWED_CALLBACK = Callable[
+    [EventBase, StateMap[EventBase]], Awaitable[Tuple[bool, Optional[dict]]]
+]
+ON_CREATE_ROOM_CALLBACK = Callable[[Requester, dict, bool], Awaitable]
+CHECK_THREEPID_CAN_BE_INVITED_CALLBACK = Callable[
+    [str, str, StateMap[EventBase]], Awaitable[bool]
+]
+CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK = Callable[
+    [str, StateMap[EventBase], str], Awaitable[bool]
+]
+ON_NEW_EVENT_CALLBACK = Callable[[EventBase, StateMap[EventBase]], Awaitable]
+CHECK_CAN_SHUTDOWN_ROOM_CALLBACK = Callable[[str, str], Awaitable[bool]]
+CHECK_CAN_DEACTIVATE_USER_CALLBACK = Callable[[str, bool], Awaitable[bool]]
+ON_PROFILE_UPDATE_CALLBACK = Callable[[str, ProfileInfo, bool, bool], Awaitable]
+ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK = Callable[[str, bool, bool], Awaitable]
+ON_THREEPID_BIND_CALLBACK = Callable[[str, str, str], Awaitable]
+ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK = Callable[[str, str, str], Awaitable]
+ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK = Callable[[str, str, str], Awaitable]
+
+
+def load_legacy_third_party_event_rules(hs: "HomeServer") -> None:
+    """Wrapper that loads a third party event rules module configured using the old
+    configuration, and registers the hooks they implement.
+    """
+    if hs.config.thirdpartyrules.third_party_event_rules is None:
+        return
+
+    module, config = hs.config.thirdpartyrules.third_party_event_rules
+
+    api = hs.get_module_api()
+    third_party_rules = module(config=config, module_api=api)
+
+    # The known hooks. If a module implements a method which name appears in this set,
+    # we'll want to register it.
+    third_party_event_rules_methods = {
+        "check_event_allowed",
+        "on_create_room",
+        "check_threepid_can_be_invited",
+        "check_visibility_can_be_modified",
+    }
+
+    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
+
+        # We return a separate wrapper for these methods because, in order to wrap them
+        # correctly, we need to await its result. Therefore it doesn't make a lot of
+        # sense to make it go through the run() wrapper.
+        if f.__name__ == "check_event_allowed":
+            # We need to wrap check_event_allowed because its old form would return either
+            # a boolean or a dict, but now we want to return the dict separately from the
+            # boolean.
+            async def wrap_check_event_allowed(
+                event: EventBase,
+                state_events: StateMap[EventBase],
+            ) -> Tuple[bool, Optional[dict]]:
+                # 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
+
+                res = await f(event, state_events)
+                if isinstance(res, dict):
+                    return True, res
+                else:
+                    return res, None
+
+            return wrap_check_event_allowed
+
+        if f.__name__ == "on_create_room":
+            # We need to wrap on_create_room because its old form would return a boolean
+            # if the room creation is denied, but now we just want it to raise an
+            # exception.
+            async def wrap_on_create_room(
+                requester: Requester, config: dict, is_requester_admin: bool
+            ) -> None:
+                # 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
+
+                res = await f(requester, config, is_requester_admin)
+                if res is False:
+                    raise SynapseError(
+                        403,
+                        "Room creation forbidden with these parameters",
+                    )
+
+            return wrap_on_create_room
+
+        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 f is not None
+
+            return maybe_awaitable(f(*args, **kwargs))
+
+        return run
+
+    # Register the hooks through the module API.
+    hooks = {
+        hook: async_wrapper(getattr(third_party_rules, hook, None))
+        for hook in third_party_event_rules_methods
+    }
+
+    api.register_third_party_rules_callbacks(**hooks)
+
+
+class ThirdPartyEventRulesModuleApiCallbacks:
+    def __init__(self) -> None:
+        self.check_event_allowed_callbacks: List[CHECK_EVENT_ALLOWED_CALLBACK] = []
+        self.on_create_room_callbacks: List[ON_CREATE_ROOM_CALLBACK] = []
+        self.check_threepid_can_be_invited_callbacks: List[
+            CHECK_THREEPID_CAN_BE_INVITED_CALLBACK
+        ] = []
+        self.check_visibility_can_be_modified_callbacks: List[
+            CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK
+        ] = []
+        self.on_new_event_callbacks: List[ON_NEW_EVENT_CALLBACK] = []
+        self.check_can_shutdown_room_callbacks: List[
+            CHECK_CAN_SHUTDOWN_ROOM_CALLBACK
+        ] = []
+        self.check_can_deactivate_user_callbacks: List[
+            CHECK_CAN_DEACTIVATE_USER_CALLBACK
+        ] = []
+        self.on_profile_update_callbacks: List[ON_PROFILE_UPDATE_CALLBACK] = []
+        self.on_user_deactivation_status_changed_callbacks: List[
+            ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK
+        ] = []
+        self.on_threepid_bind_callbacks: List[ON_THREEPID_BIND_CALLBACK] = []
+        self.on_add_user_third_party_identifier_callbacks: List[
+            ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
+        ] = []
+        self.on_remove_user_third_party_identifier_callbacks: List[
+            ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
+        ] = []
+
+    def register_callbacks(
+        self,
+        check_event_allowed: Optional[CHECK_EVENT_ALLOWED_CALLBACK] = None,
+        on_create_room: Optional[ON_CREATE_ROOM_CALLBACK] = None,
+        check_threepid_can_be_invited: Optional[
+            CHECK_THREEPID_CAN_BE_INVITED_CALLBACK
+        ] = None,
+        check_visibility_can_be_modified: Optional[
+            CHECK_VISIBILITY_CAN_BE_MODIFIED_CALLBACK
+        ] = None,
+        on_new_event: Optional[ON_NEW_EVENT_CALLBACK] = None,
+        check_can_shutdown_room: Optional[CHECK_CAN_SHUTDOWN_ROOM_CALLBACK] = None,
+        check_can_deactivate_user: Optional[CHECK_CAN_DEACTIVATE_USER_CALLBACK] = None,
+        on_profile_update: Optional[ON_PROFILE_UPDATE_CALLBACK] = None,
+        on_user_deactivation_status_changed: Optional[
+            ON_USER_DEACTIVATION_STATUS_CHANGED_CALLBACK
+        ] = None,
+        on_threepid_bind: Optional[ON_THREEPID_BIND_CALLBACK] = None,
+        on_add_user_third_party_identifier: Optional[
+            ON_ADD_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
+        ] = None,
+        on_remove_user_third_party_identifier: Optional[
+            ON_REMOVE_USER_THIRD_PARTY_IDENTIFIER_CALLBACK
+        ] = None,
+    ) -> None:
+        """Register callbacks from modules for each hook."""
+        if check_event_allowed is not None:
+            self.check_event_allowed_callbacks.append(check_event_allowed)
+
+        if on_create_room is not None:
+            self.on_create_room_callbacks.append(on_create_room)
+
+        if check_threepid_can_be_invited is not None:
+            self.check_threepid_can_be_invited_callbacks.append(
+                check_threepid_can_be_invited,
+            )
+
+        if check_visibility_can_be_modified is not None:
+            self.check_visibility_can_be_modified_callbacks.append(
+                check_visibility_can_be_modified,
+            )
+
+        if on_new_event is not None:
+            self.on_new_event_callbacks.append(on_new_event)
+
+        if check_can_shutdown_room is not None:
+            self.check_can_shutdown_room_callbacks.append(check_can_shutdown_room)
+
+        if check_can_deactivate_user is not None:
+            self.check_can_deactivate_user_callbacks.append(check_can_deactivate_user)
+
+        if on_profile_update is not None:
+            self.on_profile_update_callbacks.append(on_profile_update)
+
+        if on_user_deactivation_status_changed is not None:
+            self.on_user_deactivation_status_changed_callbacks.append(
+                on_user_deactivation_status_changed,
+            )
+
+        if on_threepid_bind is not None:
+            self.on_threepid_bind_callbacks.append(on_threepid_bind)
+
+        if on_add_user_third_party_identifier is not None:
+            self.on_add_user_third_party_identifier_callbacks.append(
+                on_add_user_third_party_identifier
+            )
+
+        if on_remove_user_third_party_identifier is not None:
+            self.on_remove_user_third_party_identifier_callbacks.append(
+                on_remove_user_third_party_identifier
+            )

synapse/rest/admin/users.py

@@ -683,19 +683,18 @@ class AccountValidityRenewServlet(RestServlet):
     PATTERNS = admin_patterns("/account_validity/validity$")
 
     def __init__(self, hs: "HomeServer"):
-        self.account_activity_handler = hs.get_account_validity_handler()
+        self.account_validity_handler = hs.get_account_validity_handler()
+        self.account_validity_module_callbacks = (
+            hs.get_module_api_callbacks().account_validity
+        )
         self.auth = hs.get_auth()
 
     async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
         await assert_requester_is_admin(self.auth, request)
 
-        if self.account_activity_handler.on_legacy_admin_request_callback:
-            expiration_ts = (
-                await (
-                    self.account_activity_handler.on_legacy_admin_request_callback(
-                        request
-                    )
-                )
+        if self.account_validity_module_callbacks.on_legacy_admin_request_callback:
+            expiration_ts = await self.account_validity_module_callbacks.on_legacy_admin_request_callback(
+                request
             )
         else:
             body = parse_json_object_from_request(request)
@@ -706,7 +705,7 @@ class AccountValidityRenewServlet(RestServlet):
                     "Missing property 'user_id' in the request body",
                 )
 
-            expiration_ts = await self.account_activity_handler.renew_account_for_user(
+            expiration_ts = await self.account_validity_handler.renew_account_for_user(
                 body["user_id"],
                 body.get("expiration_ts"),
                 not body.get("enable_renewal_emails", True),

synapse/server.py

@@ -108,6 +108,7 @@ from synapse.http.matrixfederationclient import MatrixFederationHttpClient
 from synapse.media.media_repository import MediaRepository
 from synapse.metrics.common_usage_metrics import CommonUsageMetricsManager
 from synapse.module_api import ModuleApi
+from synapse.module_api.callbacks import ModuleApiCallbacks
 from synapse.notifier import Notifier, ReplicationNotifier
 from synapse.push.bulk_push_rule_evaluator import BulkPushRuleEvaluator
 from synapse.push.pusherpool import PusherPool
@@ -673,7 +674,7 @@ class HomeServer(metaclass=abc.ABCMeta):
 
     @cache_in_self
     def get_password_auth_provider(self) -> PasswordAuthProvider:
-        return PasswordAuthProvider()
+        return PasswordAuthProvider(self)
 
     @cache_in_self
     def get_room_member_handler(self) -> RoomMemberHandler:
@@ -777,6 +778,10 @@ class HomeServer(metaclass=abc.ABCMeta):
     def get_module_api(self) -> ModuleApi:
         return ModuleApi(self, self.get_auth_handler())
 
+    @cache_in_self
+    def get_module_api_callbacks(self) -> ModuleApiCallbacks:
+        return ModuleApiCallbacks()
+
     @cache_in_self
     def get_account_data_handler(self) -> AccountDataHandler:
         return AccountDataHandler(self)

synapse/storage/background_updates.py

@@ -42,11 +42,6 @@ if TYPE_CHECKING:
 logger = logging.getLogger(__name__)
 
 
-ON_UPDATE_CALLBACK = Callable[[str, str, bool], AsyncContextManager[int]]
-DEFAULT_BATCH_SIZE_CALLBACK = Callable[[str, str], Awaitable[int]]
-MIN_BATCH_SIZE_CALLBACK = Callable[[str, str], Awaitable[int]]
-
-
 @attr.s(slots=True, frozen=True, auto_attribs=True)
 class _BackgroundUpdateHandler:
     """A handler for a given background update.
@@ -149,13 +144,11 @@ class BackgroundUpdater:
 
         self._database_name = database.name()
 
+        self._module_api_callbacks = hs.get_module_api_callbacks().background_updater
+
         # if a background update is currently running, its name.
         self._current_background_update: Optional[str] = None
 
-        self._on_update_callback: Optional[ON_UPDATE_CALLBACK] = None
-        self._default_batch_size_callback: Optional[DEFAULT_BATCH_SIZE_CALLBACK] = None
-        self._min_batch_size_callback: Optional[MIN_BATCH_SIZE_CALLBACK] = None
-
         self._background_update_performance: Dict[str, BackgroundUpdatePerformance] = {}
         self._background_update_handlers: Dict[str, _BackgroundUpdateHandler] = {}
         self._all_done = False
@@ -175,31 +168,6 @@ class BackgroundUpdater:
         self.sleep_duration_ms = hs.config.background_updates.sleep_duration_ms
         self.sleep_enabled = hs.config.background_updates.sleep_enabled
 
-    def register_update_controller_callbacks(
-        self,
-        on_update: ON_UPDATE_CALLBACK,
-        default_batch_size: Optional[DEFAULT_BATCH_SIZE_CALLBACK] = None,
-        min_batch_size: Optional[DEFAULT_BATCH_SIZE_CALLBACK] = None,
-    ) -> None:
-        """Register callbacks from a module for each hook."""
-        if self._on_update_callback is not None:
-            logger.warning(
-                "More than one module tried to register callbacks for controlling"
-                " background updates. Only the callbacks registered by the first module"
-                " (in order of appearance in Synapse's configuration file) that tried to"
-                " do so will be called."
-            )
-
-            return
-
-        self._on_update_callback = on_update
-
-        if default_batch_size is not None:
-            self._default_batch_size_callback = default_batch_size
-
-        if min_batch_size is not None:
-            self._min_batch_size_callback = min_batch_size
-
     def _get_context_manager_for_update(
         self,
         sleep: bool,
@@ -228,8 +196,10 @@ class BackgroundUpdater:
             Note: this is a *target*, and an iteration may take substantially longer or
             shorter.
         """
-        if self._on_update_callback is not None:
-            return self._on_update_callback(update_name, database_name, oneshot)
+        if self._module_api_callbacks.on_update_callback is not None:
+            return self._module_api_callbacks.on_update_callback(
+                update_name, database_name, oneshot
+            )
 
         return _BackgroundUpdateContextManager(
             sleep, self._clock, self.sleep_duration_ms, self.update_duration_ms
@@ -239,8 +209,10 @@ class BackgroundUpdater:
         """The batch size to use for the first iteration of a new background
         update.
         """
-        if self._default_batch_size_callback is not None:
-            return await self._default_batch_size_callback(update_name, database_name)
+        if self._module_api_callbacks.default_batch_size_callback is not None:
+            return await self._module_api_callbacks.default_batch_size_callback(
+                update_name, database_name
+            )
 
         return self.default_background_batch_size
 
@@ -249,8 +221,10 @@ class BackgroundUpdater:
 
         Used to ensure that progress is always made. Must be greater than 0.
         """
-        if self._min_batch_size_callback is not None:
-            return await self._min_batch_size_callback(update_name, database_name)
+        if self._module_api_callbacks.min_batch_size_callback is not None:
+            return await self._module_api_callbacks.min_batch_size_callback(
+                update_name, database_name
+            )
 
         return self.minimum_background_batch_size
 

tests/events/test_presence_router.py

@@ -19,10 +19,13 @@ import attr
 from twisted.test.proto_helpers import MemoryReactor
 
 from synapse.api.constants import EduTypes
-from synapse.events.presence_router import PresenceRouter, load_legacy_presence_router
+from synapse.events.presence_router import PresenceRouter
 from synapse.federation.units import Transaction
 from synapse.handlers.presence import UserPresenceState
 from synapse.module_api import ModuleApi
+from synapse.module_api.callbacks.presence_router_callbacks import (
+    load_legacy_presence_router,
+)
 from synapse.rest import admin
 from synapse.rest.client import login, presence, room
 from synapse.server import HomeServer

tests/handlers/test_password_providers.py

@@ -727,7 +727,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
             self.called = True
 
         on_logged_out = Mock(side_effect=on_logged_out)
-        self.hs.get_password_auth_provider().on_logged_out_callbacks.append(
+        self.hs.get_module_api_callbacks().password_auth_provider.on_logged_out_callbacks.append(
             on_logged_out
         )
 
@@ -857,7 +857,9 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         )
 
         m = Mock(return_value=make_awaitable(False))
-        self.hs.get_password_auth_provider().is_3pid_allowed_callbacks = [m]
+        self.hs.get_module_api_callbacks().password_auth_provider.is_3pid_allowed_callbacks = [
+            m
+        ]
 
         self.register_user(username, "password")
         tok = self.login(username, "password")
@@ -887,7 +889,9 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase):
         m.assert_called_once_with("email", "foo@test.com", registration)
 
         m = Mock(return_value=make_awaitable(True))
-        self.hs.get_password_auth_provider().is_3pid_allowed_callbacks = [m]
+        self.hs.get_module_api_callbacks().password_auth_provider.is_3pid_allowed_callbacks = [
+            m
+        ]
 
         channel = self.make_request(
             "POST",

tests/handlers/test_user_directory.py

@@ -791,8 +791,8 @@ class UserDirectoryTestCase(unittest.HomeserverTestCase):
             return False
 
         # Configure a spam checker that does not filter any users.
-        spam_checker = self.hs.get_spam_checker()
-        spam_checker._check_username_for_spam_callbacks = [allow_all]
+        spam_checker_callbacks = self.hs.get_module_api_callbacks().spam_checker
+        spam_checker_callbacks.check_username_for_spam_callbacks = [allow_all]
 
         # The results do not change:
         # We get one search result when searching for user2 by user1.
@@ -804,7 +804,7 @@ class UserDirectoryTestCase(unittest.HomeserverTestCase):
             # All users are spammy.
             return True
 
-        spam_checker._check_username_for_spam_callbacks = [block_all]
+        spam_checker_callbacks.check_username_for_spam_callbacks = [block_all]
 
         # User1 now gets no search results for any of the other users.
         s = self.get_success(self.handler.search_users(u1, "user2", 10))

tests/media/test_media_storage.py

@@ -31,7 +31,6 @@ from twisted.test.proto_helpers import MemoryReactor
 
 from synapse.api.errors import Codes
 from synapse.events import EventBase
-from synapse.events.spamcheck import load_legacy_spam_checkers
 from synapse.http.types import QueryParams
 from synapse.logging.context import make_deferred_yieldable
 from synapse.media._base import FileInfo
@@ -39,6 +38,9 @@ from synapse.media.filepath import MediaFilePaths
 from synapse.media.media_storage import MediaStorage, ReadableFileWrapper
 from synapse.media.storage_provider import FileStorageProviderBackend
 from synapse.module_api import ModuleApi
+from synapse.module_api.callbacks.spam_checker_callbacks import (
+    load_legacy_spam_checkers,
+)
 from synapse.rest import admin
 from synapse.rest.client import login
 from synapse.server import HomeServer

tests/rest/client/test_account.py

@@ -1249,9 +1249,8 @@ class AccountStatusTestCase(unittest.HomeserverTestCase):
             # account status will fail.
             return UserID.from_string(user_id).localpart == "someuser"
 
-        self.hs.get_account_validity_handler()._is_user_expired_callbacks.append(
-            is_expired
-        )
+        account_validity_callbacks = self.hs.get_module_api_callbacks().account_validity
+        account_validity_callbacks.is_user_expired_callbacks.append(is_expired)
 
         self._test_status(
             users=[user],

tests/rest/client/test_account_data.py

@@ -33,7 +33,7 @@ class AccountDataTestCase(unittest.HomeserverTestCase):
         a user's account data changes.
         """
         mocked_callback = Mock(return_value=make_awaitable(None))
-        self.hs.get_account_data_handler()._on_account_data_updated_callbacks.append(
+        self.hs.get_module_api_callbacks().account_data.on_account_data_updated_callbacks.append(
             mocked_callback
         )
 

tests/rest/client/test_rooms.py

@@ -814,7 +814,8 @@ class RoomsCreateTestCase(RoomBase):
             return False
 
         join_mock = Mock(side_effect=user_may_join_room)
-        self.hs.get_spam_checker()._user_may_join_room_callbacks.append(join_mock)
+        spam_checker_callbacks = self.hs.get_module_api_callbacks().spam_checker
+        spam_checker_callbacks.user_may_join_room_callbacks.append(join_mock)
 
         channel = self.make_request(
             "POST",
@@ -840,7 +841,8 @@ class RoomsCreateTestCase(RoomBase):
             return Codes.CONSENT_NOT_GIVEN
 
         join_mock = Mock(side_effect=user_may_join_room_codes)
-        self.hs.get_spam_checker()._user_may_join_room_callbacks.append(join_mock)
+        spam_checker_callbacks = self.hs.get_module_api_callbacks().spam_checker
+        spam_checker_callbacks.user_may_join_room_callbacks.append(join_mock)
 
         channel = self.make_request(
             "POST",
@@ -1162,7 +1164,8 @@ class RoomJoinTestCase(RoomBase):
         # `spec` argument is needed for this function mock to have `__qualname__`, which
         # is needed for `Measure` metrics buried in SpamChecker.
         callback_mock = Mock(side_effect=user_may_join_room, spec=lambda *x: None)
-        self.hs.get_spam_checker()._user_may_join_room_callbacks.append(callback_mock)
+        spam_checker_callbacks = self.hs.get_module_api_callbacks().spam_checker
+        spam_checker_callbacks.user_may_join_room_callbacks.append(callback_mock)
 
         # Join a first room, without being invited to it.
         self.helper.join(self.room1, self.user2, tok=self.tok2)
@@ -1227,7 +1230,8 @@ class RoomJoinTestCase(RoomBase):
         # `spec` argument is needed for this function mock to have `__qualname__`, which
         # is needed for `Measure` metrics buried in SpamChecker.
         callback_mock = Mock(side_effect=user_may_join_room, spec=lambda *x: None)
-        self.hs.get_spam_checker()._user_may_join_room_callbacks.append(callback_mock)
+        spam_checker_callbacks = self.hs.get_module_api_callbacks().spam_checker
+        spam_checker_callbacks.user_may_join_room_callbacks.append(callback_mock)
 
         # Join a first room, without being invited to it.
         self.helper.join(self.room1, self.user2, tok=self.tok2)
@@ -1642,8 +1646,8 @@ class RoomMessagesTestCase(RoomBase):
                 return self.mock_return_value
 
         spam_checker = SpamCheck()
-
-        self.hs.get_spam_checker()._check_event_for_spam_callbacks.append(
+        spam_checker_callbacks = self.hs.get_module_api_callbacks().spam_checker
+        spam_checker_callbacks.check_event_for_spam_callbacks.append(
             spam_checker.check_event_for_spam
         )
 
@@ -3381,7 +3385,8 @@ class ThreepidInviteTestCase(unittest.HomeserverTestCase):
         # `spec` argument is needed for this function mock to have `__qualname__`, which
         # is needed for `Measure` metrics buried in SpamChecker.
         mock = Mock(return_value=make_awaitable(True), spec=lambda *x: None)
-        self.hs.get_spam_checker()._user_may_send_3pid_invite_callbacks.append(mock)
+        spam_checker_callbacks = self.hs.get_module_api_callbacks().spam_checker
+        spam_checker_callbacks.user_may_send_3pid_invite_callbacks.append(mock)
 
         # Send a 3PID invite into the room and check that it succeeded.
         email_to_invite = "teresa@example.com"
@@ -3446,7 +3451,8 @@ class ThreepidInviteTestCase(unittest.HomeserverTestCase):
             return_value=make_awaitable(synapse.module_api.NOT_SPAM),
             spec=lambda *x: None,
         )
-        self.hs.get_spam_checker()._user_may_send_3pid_invite_callbacks.append(mock)
+        spam_checker_callbacks = self.hs.get_module_api_callbacks().spam_checker
+        spam_checker_callbacks.user_may_send_3pid_invite_callbacks.append(mock)
 
         # Send a 3PID invite into the room and check that it succeeded.
         email_to_invite = "teresa@example.com"

tests/rest/client/test_third_party_rules.py

@@ -22,7 +22,9 @@ from synapse.api.errors import SynapseError
 from synapse.api.room_versions import RoomVersion
 from synapse.config.homeserver import HomeServerConfig
 from synapse.events import EventBase
-from synapse.events.third_party_rules import load_legacy_third_party_event_rules
+from synapse.module_api.callbacks.third_party_event_rules_callbacks import (
+    load_legacy_third_party_event_rules,
+)
 from synapse.rest import admin
 from synapse.rest.client import account, login, profile, room
 from synapse.server import HomeServer
@@ -146,7 +148,7 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
             return ev.type != "foo.bar.forbidden", None
 
         callback = Mock(spec=[], side_effect=check)
-        self.hs.get_third_party_event_rules()._check_event_allowed_callbacks = [
+        self.hs.get_module_api_callbacks().third_party_event_rules.check_event_allowed_callbacks = [
             callback
         ]
 
@@ -202,7 +204,9 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
         ) -> Tuple[bool, Optional[JsonDict]]:
             raise NastyHackException(429, "message")
 
-        self.hs.get_third_party_event_rules()._check_event_allowed_callbacks = [check]
+        self.hs.get_module_api_callbacks().third_party_event_rules.check_event_allowed_callbacks = [
+            check
+        ]
 
         # Make a request
         channel = self.make_request(
@@ -229,7 +233,9 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
             ev.content = {"x": "y"}
             return True, None
 
-        self.hs.get_third_party_event_rules()._check_event_allowed_callbacks = [check]
+        self.hs.get_module_api_callbacks().third_party_event_rules.check_event_allowed_callbacks = [
+            check
+        ]
 
         # now send the event
         channel = self.make_request(
@@ -253,7 +259,9 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
             d["content"] = {"x": "y"}
             return True, d
 
-        self.hs.get_third_party_event_rules()._check_event_allowed_callbacks = [check]
+        self.hs.get_module_api_callbacks().third_party_event_rules.check_event_allowed_callbacks = [
+            check
+        ]
 
         # now send the event
         channel = self.make_request(
@@ -289,7 +297,9 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
             }
             return True, d
 
-        self.hs.get_third_party_event_rules()._check_event_allowed_callbacks = [check]
+        self.hs.get_module_api_callbacks().third_party_event_rules.check_event_allowed_callbacks = [
+            check
+        ]
 
         # Send an event, then edit it.
         channel = self.make_request(
@@ -440,7 +450,9 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
                 )
             return True, None
 
-        self.hs.get_third_party_event_rules()._check_event_allowed_callbacks = [test_fn]
+        self.hs.get_module_api_callbacks().third_party_event_rules.check_event_allowed_callbacks = [
+            test_fn
+        ]
 
         # Sometimes the bug might not happen the first time the event type is added
         # to the state but might happen when an event updates the state of the room for
@@ -466,7 +478,7 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
     def test_on_new_event(self) -> None:
         """Test that the on_new_event callback is called on new events"""
         on_new_event = Mock(make_awaitable(None))
-        self.hs.get_third_party_event_rules()._on_new_event_callbacks.append(
+        self.hs.get_module_api_callbacks().third_party_event_rules.on_new_event_callbacks.append(
             on_new_event
         )
 
@@ -569,7 +581,9 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
 
         # Register a mock callback.
         m = Mock(return_value=make_awaitable(None))
-        self.hs.get_third_party_event_rules()._on_profile_update_callbacks.append(m)
+        self.hs.get_module_api_callbacks().third_party_event_rules.on_profile_update_callbacks.append(
+            m
+        )
 
         # Change the display name.
         channel = self.make_request(
@@ -628,7 +642,9 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
 
         # Register a mock callback.
         m = Mock(return_value=make_awaitable(None))
-        self.hs.get_third_party_event_rules()._on_profile_update_callbacks.append(m)
+        self.hs.get_module_api_callbacks().third_party_event_rules.on_profile_update_callbacks.append(
+            m
+        )
 
         # Register an admin user.
         self.register_user("admin", "password", admin=True)
@@ -667,15 +683,15 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
         """
         # Register a mocked callback.
         deactivation_mock = Mock(return_value=make_awaitable(None))
-        third_party_rules = self.hs.get_third_party_event_rules()
-        third_party_rules._on_user_deactivation_status_changed_callbacks.append(
+        third_party_rules = self.hs.get_module_api_callbacks().third_party_event_rules
+        third_party_rules.on_user_deactivation_status_changed_callbacks.append(
             deactivation_mock,
         )
         # Also register a mocked callback for profile updates, to check that the
         # deactivation code calls it in a way that let modules know the user is being
         # deactivated.
         profile_mock = Mock(return_value=make_awaitable(None))
-        self.hs.get_third_party_event_rules()._on_profile_update_callbacks.append(
+        self.hs.get_module_api_callbacks().third_party_event_rules.on_profile_update_callbacks.append(
             profile_mock,
         )
 
@@ -725,8 +741,8 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
         """
         # Register a mock callback.
         m = Mock(return_value=make_awaitable(None))
-        third_party_rules = self.hs.get_third_party_event_rules()
-        third_party_rules._on_user_deactivation_status_changed_callbacks.append(m)
+        third_party_rules = self.hs.get_module_api_callbacks().third_party_event_rules
+        third_party_rules.on_user_deactivation_status_changed_callbacks.append(m)
 
         # Register an admin user.
         self.register_user("admin", "password", admin=True)
@@ -779,8 +795,8 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
         """
         # Register a mocked callback.
         deactivation_mock = Mock(return_value=make_awaitable(False))
-        third_party_rules = self.hs.get_third_party_event_rules()
-        third_party_rules._check_can_deactivate_user_callbacks.append(
+        third_party_rules = self.hs.get_module_api_callbacks().third_party_event_rules
+        third_party_rules.check_can_deactivate_user_callbacks.append(
             deactivation_mock,
         )
 
@@ -825,8 +841,8 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
         """
         # Register a mocked callback.
         deactivation_mock = Mock(return_value=make_awaitable(False))
-        third_party_rules = self.hs.get_third_party_event_rules()
-        third_party_rules._check_can_deactivate_user_callbacks.append(
+        third_party_rules = self.hs.get_module_api_callbacks().third_party_event_rules
+        third_party_rules.check_can_deactivate_user_callbacks.append(
             deactivation_mock,
         )
 
@@ -864,8 +880,8 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
         """
         # Register a mocked callback.
         shutdown_mock = Mock(return_value=make_awaitable(False))
-        third_party_rules = self.hs.get_third_party_event_rules()
-        third_party_rules._check_can_shutdown_room_callbacks.append(
+        third_party_rules = self.hs.get_module_api_callbacks().third_party_event_rules
+        third_party_rules.check_can_shutdown_room_callbacks.append(
             shutdown_mock,
         )
 
@@ -900,8 +916,8 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
         """
         # Register a mocked callback.
         threepid_bind_mock = Mock(return_value=make_awaitable(None))
-        third_party_rules = self.hs.get_third_party_event_rules()
-        third_party_rules._on_threepid_bind_callbacks.append(threepid_bind_mock)
+        third_party_rules = self.hs.get_module_api_callbacks().third_party_event_rules
+        third_party_rules.on_threepid_bind_callbacks.append(threepid_bind_mock)
 
         # Register an admin user.
         self.register_user("admin", "password", admin=True)
@@ -941,17 +957,17 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
         just before associating and removing a 3PID to/from an account.
         """
         # Pretend to be a Synapse module and register both callbacks as mocks.
-        third_party_rules = self.hs.get_third_party_event_rules()
+        third_party_rules = self.hs.get_module_api_callbacks().third_party_event_rules
         on_add_user_third_party_identifier_callback_mock = Mock(
             return_value=make_awaitable(None)
         )
         on_remove_user_third_party_identifier_callback_mock = Mock(
             return_value=make_awaitable(None)
         )
-        third_party_rules._on_threepid_bind_callbacks.append(
+        third_party_rules.on_threepid_bind_callbacks.append(
             on_add_user_third_party_identifier_callback_mock
         )
-        third_party_rules._on_threepid_bind_callbacks.append(
+        third_party_rules.on_threepid_bind_callbacks.append(
             on_remove_user_third_party_identifier_callback_mock
         )
 
@@ -1008,11 +1024,11 @@ class ThirdPartyRulesTestCase(unittest.FederatingHomeserverTestCase):
         when a user is deactivated and their third-party ID associations are deleted.
         """
         # Pretend to be a Synapse module and register both callbacks as mocks.
-        third_party_rules = self.hs.get_third_party_event_rules()
+        third_party_rules = self.hs.get_module_api_callbacks().third_party_event_rules
         on_remove_user_third_party_identifier_callback_mock = Mock(
             return_value=make_awaitable(None)
         )
-        third_party_rules._on_threepid_bind_callbacks.append(
+        third_party_rules.on_threepid_bind_callbacks.append(
             on_remove_user_third_party_identifier_callback_mock
         )
 

tests/server.py

@@ -71,12 +71,18 @@ from twisted.web.server import Request, Site
 
 from synapse.config.database import DatabaseConnectionConfig
 from synapse.config.homeserver import HomeServerConfig
-from synapse.events.presence_router import load_legacy_presence_router
-from synapse.events.spamcheck import load_legacy_spam_checkers
-from synapse.events.third_party_rules import load_legacy_third_party_event_rules
 from synapse.handlers.auth import load_legacy_password_auth_providers
 from synapse.http.site import SynapseRequest
 from synapse.logging.context import ContextResourceUsage
+from synapse.module_api.callbacks.presence_router_callbacks import (
+    load_legacy_presence_router,
+)
+from synapse.module_api.callbacks.spam_checker_callbacks import (
+    load_legacy_spam_checkers,
+)
+from synapse.module_api.callbacks.third_party_event_rules_callbacks import (
+    load_legacy_third_party_event_rules,
+)
 from synapse.server import HomeServer
 from synapse.storage import DataStore
 from synapse.storage.engines import PostgresEngine, create_engine