From 67feea8044562764b04c4968ebf159b44eb59218 Mon Sep 17 00:00:00 2001 From: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com> Date: Fri, 8 May 2020 19:25:48 +0100 Subject: [PATCH] Extend spam checker to allow for multiple modules (#7435) --- changelog.d/7435.feature | 1 + docs/sample_config.yaml | 15 ++++-- docs/spam_checker.md | 19 ++++--- synapse/config/spam_checker.py | 38 +++++++++++--- synapse/events/spamcheck.py | 76 +++++++++++++-------------- tests/handlers/test_user_directory.py | 4 +- 6 files changed, 94 insertions(+), 59 deletions(-) create mode 100644 changelog.d/7435.feature diff --git a/changelog.d/7435.feature b/changelog.d/7435.feature new file mode 100644 index 000000000..399291b13 --- /dev/null +++ b/changelog.d/7435.feature @@ -0,0 +1 @@ +Allow for using more than one spam checker module at once. \ No newline at end of file diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml index 1e397f773..5abeaf519 100644 --- a/docs/sample_config.yaml +++ b/docs/sample_config.yaml @@ -1867,10 +1867,17 @@ password_providers: # include_content: true -#spam_checker: -# module: "my_custom_project.SuperSpamChecker" -# config: -# example_option: 'things' +# Spam checkers are third-party modules that can block specific actions +# of local users, such as creating rooms and registering undesirable +# usernames, as well as remote users by redacting incoming events. +# +spam_checker: + #- module: "my_custom_project.SuperSpamChecker" + # config: + # example_option: 'things' + #- module: "some_other_project.BadEventStopper" + # config: + # example_stop_events_from: ['@bad:example.com'] # Uncomment to allow non-server-admin users to create groups on this server diff --git a/docs/spam_checker.md b/docs/spam_checker.md index 5b5f5000b..eb10e115f 100644 --- a/docs/spam_checker.md +++ b/docs/spam_checker.md @@ -64,10 +64,12 @@ class ExampleSpamChecker: Modify the `spam_checker` section of your `homeserver.yaml` in the following manner: -`module` should point to the fully qualified Python class that implements your -custom logic, e.g. `my_module.ExampleSpamChecker`. +Create a list entry with the keys `module` and `config`. -`config` is a dictionary that gets passed to the spam checker class. +* `module` should point to the fully qualified Python class that implements your + custom logic, e.g. `my_module.ExampleSpamChecker`. + +* `config` is a dictionary that gets passed to the spam checker class. ### Example @@ -75,12 +77,15 @@ This section might look like: ```yaml spam_checker: - module: my_module.ExampleSpamChecker - config: - # Enable or disable a specific option in ExampleSpamChecker. - my_custom_option: true + - module: my_module.ExampleSpamChecker + config: + # Enable or disable a specific option in ExampleSpamChecker. + my_custom_option: true ``` +More spam checkers can be added in tandem by appending more items to the list. An +action is blocked when at least one of the configured spam checkers flags it. + ## Examples The [Mjolnir](https://github.com/matrix-org/mjolnir) project is a full fledged diff --git a/synapse/config/spam_checker.py b/synapse/config/spam_checker.py index 36e0ddab5..3d067d29d 100644 --- a/synapse/config/spam_checker.py +++ b/synapse/config/spam_checker.py @@ -13,6 +13,9 @@ # See the License for the specific language governing permissions and # limitations under the License. +from typing import Any, Dict, List, Tuple + +from synapse.config import ConfigError from synapse.util.module_loader import load_module from ._base import Config @@ -22,16 +25,35 @@ class SpamCheckerConfig(Config): section = "spamchecker" def read_config(self, config, **kwargs): - self.spam_checker = None + self.spam_checkers = [] # type: List[Tuple[Any, Dict]] - provider = config.get("spam_checker", None) - if provider is not None: - self.spam_checker = load_module(provider) + spam_checkers = config.get("spam_checker") or [] + if isinstance(spam_checkers, dict): + # The spam_checker config option used to only support one + # spam checker, and thus was simply a dictionary with module + # and config keys. Support this old behaviour by checking + # to see if the option resolves to a dictionary + self.spam_checkers.append(load_module(spam_checkers)) + elif isinstance(spam_checkers, list): + for spam_checker in spam_checkers: + if not isinstance(spam_checker, dict): + raise ConfigError("spam_checker syntax is incorrect") + + self.spam_checkers.append(load_module(spam_checker)) + else: + raise ConfigError("spam_checker syntax is incorrect") def generate_config_section(self, **kwargs): return """\ - #spam_checker: - # module: "my_custom_project.SuperSpamChecker" - # config: - # example_option: 'things' + # Spam checkers are third-party modules that can block specific actions + # of local users, such as creating rooms and registering undesirable + # usernames, as well as remote users by redacting incoming events. + # + spam_checker: + #- module: "my_custom_project.SuperSpamChecker" + # config: + # example_option: 'things' + #- module: "some_other_project.BadEventStopper" + # config: + # example_stop_events_from: ['@bad:example.com'] """ diff --git a/synapse/events/spamcheck.py b/synapse/events/spamcheck.py index a23b6b7b6..1ffc9525d 100644 --- a/synapse/events/spamcheck.py +++ b/synapse/events/spamcheck.py @@ -15,7 +15,7 @@ # limitations under the License. import inspect -from typing import Dict +from typing import Any, Dict, List from synapse.spam_checker_api import SpamCheckerApi @@ -26,24 +26,17 @@ if MYPY: class SpamChecker(object): def __init__(self, hs: "synapse.server.HomeServer"): - self.spam_checker = None + self.spam_checkers = [] # type: List[Any] - module = None - config = None - try: - module, config = hs.config.spam_checker - except Exception: - pass - - if module is not None: + for module, config in hs.config.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: api = SpamCheckerApi(hs) - self.spam_checker = module(config=config, api=api) + self.spam_checkers.append(module(config=config, api=api)) else: - self.spam_checker = module(config=config) + self.spam_checkers.append(module(config=config)) def check_event_for_spam(self, event: "synapse.events.EventBase") -> bool: """Checks if a given event is considered "spammy" by this server. @@ -58,10 +51,11 @@ class SpamChecker(object): Returns: True if the event is spammy. """ - if self.spam_checker is None: - return False + for spam_checker in self.spam_checkers: + if spam_checker.check_event_for_spam(event): + return True - return self.spam_checker.check_event_for_spam(event) + return False def user_may_invite( self, inviter_userid: str, invitee_userid: str, room_id: str @@ -78,12 +72,14 @@ class SpamChecker(object): Returns: True if the user may send an invite, otherwise False """ - if self.spam_checker is None: - return True + for spam_checker in self.spam_checkers: + if ( + spam_checker.user_may_invite(inviter_userid, invitee_userid, room_id) + is False + ): + return False - return self.spam_checker.user_may_invite( - inviter_userid, invitee_userid, room_id - ) + return True def user_may_create_room(self, userid: str) -> bool: """Checks if a given user may create a room @@ -96,10 +92,11 @@ class SpamChecker(object): Returns: True if the user may create a room, otherwise False """ - if self.spam_checker is None: - return True + for spam_checker in self.spam_checkers: + if spam_checker.user_may_create_room(userid) is False: + return False - return self.spam_checker.user_may_create_room(userid) + return True def user_may_create_room_alias(self, userid: str, room_alias: str) -> bool: """Checks if a given user may create a room alias @@ -113,10 +110,11 @@ class SpamChecker(object): Returns: True if the user may create a room alias, otherwise False """ - if self.spam_checker is None: - return True + for spam_checker in self.spam_checkers: + if spam_checker.user_may_create_room_alias(userid, room_alias) is False: + return False - return self.spam_checker.user_may_create_room_alias(userid, room_alias) + return True def user_may_publish_room(self, userid: str, room_id: str) -> bool: """Checks if a given user may publish a room to the directory @@ -130,10 +128,11 @@ class SpamChecker(object): Returns: True if the user may publish the room, otherwise False """ - if self.spam_checker is None: - return True + for spam_checker in self.spam_checkers: + if spam_checker.user_may_publish_room(userid, room_id) is False: + return False - return self.spam_checker.user_may_publish_room(userid, room_id) + return True def check_username_for_spam(self, user_profile: Dict[str, str]) -> bool: """Checks if a user ID or display name are considered "spammy" by this server. @@ -150,13 +149,14 @@ class SpamChecker(object): Returns: True if the user is spammy. """ - if self.spam_checker is None: - return False + for spam_checker in self.spam_checkers: + # For backwards compatibility, only run if the method exists on the + # spam checker + checker = getattr(spam_checker, "check_username_for_spam", None) + if checker: + # Make a copy of the user profile object to ensure the spam checker + # cannot modify it. + if checker(user_profile.copy()): + return True - # For backwards compatibility, if the method does not exist on the spam checker, fallback to not interfering. - checker = getattr(self.spam_checker, "check_username_for_spam", None) - if not checker: - return False - # Make a copy of the user profile object to ensure the spam checker - # cannot modify it. - return checker(user_profile.copy()) + return False diff --git a/tests/handlers/test_user_directory.py b/tests/handlers/test_user_directory.py index 7b92bdbc4..572df8d80 100644 --- a/tests/handlers/test_user_directory.py +++ b/tests/handlers/test_user_directory.py @@ -185,7 +185,7 @@ class UserDirectoryTestCase(unittest.HomeserverTestCase): # Allow all users. return False - spam_checker.spam_checker = AllowAll() + spam_checker.spam_checkers = [AllowAll()] # The results do not change: # We get one search result when searching for user2 by user1. @@ -198,7 +198,7 @@ class UserDirectoryTestCase(unittest.HomeserverTestCase): # All users are spammy. return True - spam_checker.spam_checker = BlockAll() + spam_checker.spam_checkers = [BlockAll()] # User1 now gets no search results for any of the other users. s = self.get_success(self.handler.search_users(u1, "user2", 10))