diff options
Diffstat (limited to 'synapse/module_api/callbacks')
| -rw-r--r-- | synapse/module_api/callbacks/__init__.py | 4 | ||||
| -rw-r--r-- | synapse/module_api/callbacks/third_party_event_rules_callbacks.py | 591 |
2 files changed, 595 insertions, 0 deletions
diff --git a/synapse/module_api/callbacks/__init__.py b/synapse/module_api/callbacks/__init__.py index 5cdb2c003a..dcb036552b 100644 --- a/synapse/module_api/callbacks/__init__.py +++ b/synapse/module_api/callbacks/__init__.py @@ -23,9 +23,13 @@ from synapse.module_api.callbacks.account_validity_callbacks import ( from synapse.module_api.callbacks.spamchecker_callbacks import ( SpamCheckerModuleApiCallbacks, ) +from synapse.module_api.callbacks.third_party_event_rules_callbacks import ( + ThirdPartyEventRulesModuleApiCallbacks, +) class ModuleApiCallbacks: def __init__(self, hs: "HomeServer") -> None: self.account_validity = AccountValidityModuleApiCallbacks() self.spam_checker = SpamCheckerModuleApiCallbacks(hs) + self.third_party_event_rules = ThirdPartyEventRulesModuleApiCallbacks(hs) diff --git a/synapse/module_api/callbacks/third_party_event_rules_callbacks.py b/synapse/module_api/callbacks/third_party_event_rules_callbacks.py new file mode 100644 index 0000000000..911f37ba42 --- /dev/null +++ b/synapse/module_api/callbacks/third_party_event_rules_callbacks.py @@ -0,0 +1,591 @@ +# Copyright 2019 The Matrix.org Foundation C.I.C. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +import logging +from typing import TYPE_CHECKING, Any, Awaitable, Callable, List, Optional, Tuple + +from twisted.internet.defer import CancelledError + +from synapse.api.errors import ModuleFailedException, SynapseError +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 + +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: + """Allows server admins to provide a Python module implementing an extra + set of rules to apply when processing events. + + This is designed to help admins of closed federations with enforcing custom + behaviours. + """ + + def __init__(self, hs: "HomeServer"): + 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 + ) + + 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 + ) + + async def check_event_allowed( + self, + event: EventBase, + context: UnpersistedEventContextBase, + ) -> Tuple[bool, Optional[dict]]: + """Check if a provided event should be allowed in the given context. + + The module can return: + * True: the event is allowed. + * False: the event is not allowed, and should be rejected with M_FORBIDDEN. + + If the event is allowed, the module can also return a dictionary to use as a + replacement for the event. + + Args: + event: The event to be checked. + context: The context of the event. + + Returns: + 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: + return True, None + + prev_state_ids = await context.get_prev_state_ids() + + # Retrieve the state events from the database. + events = await self.store.get_events(prev_state_ids.values()) + state_events = {(ev.type, ev.state_key): ev for ev in events.values()} + + # Ensure that the event is frozen, to make sure that the module is not tempted + # to try to modify it. Any attempt to modify it at this point will invalidate + # the hashes and signatures. + event.freeze() + + for callback in self._check_event_allowed_callbacks: + try: + res, replacement_data = await delay_cancellation( + callback(event, state_events) + ) + except CancelledError: + raise + except SynapseError as e: + # FIXME: Being able to throw SynapseErrors is relied upon by + # some modules. PR #10386 accidentally broke this ability. + # That said, we aren't keen on exposing this implementation detail + # to modules and we should one day have a proper way to do what + # is wanted. + # This module callback needs a rework so that hacks such as + # this one are not necessary. + raise e + except Exception: + raise ModuleFailedException( + "Failed to run `check_event_allowed` module API callback" + ) + + # Return if the event shouldn't be allowed or if the module came up with a + # replacement dict for the event. + if res is False: + return res, None + elif isinstance(replacement_data, dict): + return True, replacement_data + + return True, None + + async def on_create_room( + self, requester: Requester, config: dict, is_requester_admin: bool + ) -> None: + """Intercept requests to create room to maybe deny it (via an exception) or + update the request config. + + Args: + requester + config: The creation config from the client. + is_requester_admin: If the requester is an admin + """ + for callback in self._on_create_room_callbacks: + try: + await callback(requester, config, is_requester_admin) + except Exception as e: + # Don't silence the errors raised by this callback since we expect it to + # raise an exception to deny the creation of the room; instead make sure + # it's a SynapseError we can send to clients. + if not isinstance(e, SynapseError): + e = SynapseError( + 403, "Room creation forbidden with these parameters" + ) + + raise e + + async def check_threepid_can_be_invited( + self, medium: str, address: str, room_id: str + ) -> bool: + """Check if a provided 3PID can be invited in the given room. + + Args: + medium: The 3PID's medium. + address: The 3PID's address. + room_id: The room we want to invite the threepid to. + + Returns: + 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: + return True + + state_events = await self._get_state_map_for_room(room_id) + + for callback in self._check_threepid_can_be_invited_callbacks: + try: + threepid_can_be_invited = await delay_cancellation( + callback(medium, address, state_events) + ) + if threepid_can_be_invited is False: + return False + except CancelledError: + raise + except Exception as e: + logger.warning("Failed to run module API callback %s: %s", callback, e) + + return True + + async def check_visibility_can_be_modified( + self, room_id: str, new_visibility: str + ) -> bool: + """Check if a room is allowed to be published to, or removed from, the public room + list. + + Args: + room_id: The ID of the room. + new_visibility: The new visibility state. Either "public" or "private". + + Returns: + 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: + return True + + state_events = await self._get_state_map_for_room(room_id) + + for callback in self._check_visibility_can_be_modified_callbacks: + try: + visibility_can_be_modified = await delay_cancellation( + callback(room_id, state_events, new_visibility) + ) + if visibility_can_be_modified is False: + return False + except CancelledError: + raise + except Exception as e: + logger.warning("Failed to run module API callback %s: %s", callback, e) + + return True + + async def on_new_event(self, event_id: str) -> None: + """Let modules act on events after they've been sent (e.g. auto-accepting + invites, etc.) + + Args: + 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: + 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: + try: + await callback(event, state_events) + except Exception as e: + logger.exception( + "Failed to run module API callback %s: %s", callback, e + ) + + async def check_can_shutdown_room(self, user_id: str, room_id: str) -> bool: + """Intercept requests to shutdown a room. If `False` is returned, the + room must not be shut down. + + Args: + 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: + try: + can_shutdown_room = await delay_cancellation(callback(user_id, room_id)) + if can_shutdown_room is False: + return False + except CancelledError: + raise + except Exception as e: + logger.exception( + "Failed to run module API callback %s: %s", callback, e + ) + return True + + async def check_can_deactivate_user( + self, + user_id: str, + by_admin: bool, + ) -> bool: + """Intercept requests to deactivate a user. If `False` is returned, the + user should not be deactivated. + + Args: + requester + user_id: The ID of the room. + """ + for callback in self._check_can_deactivate_user_callbacks: + try: + can_deactivate_user = await delay_cancellation( + callback(user_id, by_admin) + ) + if can_deactivate_user is False: + return False + except CancelledError: + raise + except Exception as e: + logger.exception( + "Failed to run module API callback %s: %s", callback, e + ) + return True + + async def _get_state_map_for_room(self, room_id: str) -> StateMap[EventBase]: + """Given a room ID, return the state events of that room. + + Args: + room_id: The ID of the room. + + Returns: + A dict mapping (event type, state key) to state event. + """ + return await self._storage_controllers.state.get_current_state(room_id) + + async def on_profile_update( + self, user_id: str, new_profile: ProfileInfo, by_admin: bool, deactivation: bool + ) -> None: + """Called after the global profile of a user has been updated. Does not include + per-room profile changes. + + Args: + user_id: The user whose profile was changed. + new_profile: The updated profile for the user. + 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: + try: + await callback(user_id, new_profile, by_admin, deactivation) + except Exception as e: + logger.exception( + "Failed to run module API callback %s: %s", callback, e + ) + + async def on_user_deactivation_status_changed( + self, user_id: str, deactivated: bool, by_admin: bool + ) -> None: + """Called after a user has been deactivated or reactivated. + + Args: + user_id: The deactivated user. + 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: + try: + await callback(user_id, deactivated, by_admin) + except Exception as e: + logger.exception( + "Failed to run module API callback %s: %s", callback, e + ) + + async def on_threepid_bind(self, user_id: str, medium: str, address: str) -> None: + """Called after a threepid association has been verified and stored. + + Note that this callback is called when an association is created on the + local homeserver, not when it's created on an identity server (and then kept track + of so that it can be unbound on the same IS later on). + + THIS MODULE CALLBACK METHOD HAS BEEN DEPRECATED. Please use the + `on_add_user_third_party_identifier` callback method instead. + + Args: + user_id: the user being associated with the threepid. + medium: the threepid's medium. + address: the threepid's address. + """ + for callback in self._on_threepid_bind_callbacks: + try: + await callback(user_id, medium, address) + except Exception as e: + logger.exception( + "Failed to run module API callback %s: %s", callback, e + ) + + async def on_add_user_third_party_identifier( + self, user_id: str, medium: str, address: str + ) -> None: + """Called when an association between a user's Matrix ID and a third-party ID + (email, phone number) has successfully been registered on the homeserver. + + Args: + user_id: The User ID included in the association. + 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: + try: + await callback(user_id, medium, address) + except Exception as e: + logger.exception( + "Failed to run module API callback %s: %s", callback, e + ) + + async def on_remove_user_third_party_identifier( + self, user_id: str, medium: str, address: str + ) -> None: + """Called when an association between a user's Matrix ID and a third-party ID + (email, phone number) has been successfully removed on the homeserver. + + This is called *after* any known bindings on identity servers for this + association have been removed. + + Args: + user_id: The User ID included in the removed association. + 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: + try: + await callback(user_id, medium, address) + except Exception as e: + logger.exception( + "Failed to run module API callback %s: %s", callback, e + ) |