Merge pull request #3232 from matrix-org/rav/server_notices_room

Infrastructure for a server notices room

synapse/config/homeserver.py

@@ -38,6 +38,7 @@
 from .groups import GroupsConfig
 from .user_directory import UserDirectoryConfig
 from .consent_config import ConsentConfig
+from .server_notices_config import ServerNoticesConfig
 
 
 class HomeServerConfig(TlsConfig, ServerConfig, DatabaseConfig, LoggingConfig,
@@ -47,7 +48,9 @@ class HomeServerConfig(TlsConfig, ServerConfig, DatabaseConfig, LoggingConfig,
                        JWTConfig, PasswordConfig, EmailConfig,
                        WorkerConfig, PasswordAuthProviderConfig, PushConfig,
                        SpamCheckerConfig, GroupsConfig, UserDirectoryConfig,
-                       ConsentConfig):
+                       ConsentConfig,
+                       ServerNoticesConfig,
+                       ):
     pass
 
 

synapse/config/server_notices_config.py

@@ -0,0 +1,77 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vector Ltd
+#
+# 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 ._base import Config
+from synapse.types import UserID
+
+DEFAULT_CONFIG = """\
+# Server Notices room configuration
+#
+# Uncomment this section to enable a room which can be used to send notices
+# from the server to users. It is a special room which cannot be left; notices
+# come from a special "notices" user id.
+#
+# If you uncomment this section, you *must* define the system_mxid_localpart
+# setting, which defines the id of the user which will be used to send the
+# notices.
+#
+# It's also possible to override the room name, or the display name of the
+# "notices" user.
+#
+# server_notices:
+#   system_mxid_localpart: notices
+#   system_mxid_display_name: "Server Notices"
+#   room_name: "Server Notices"
+"""
+
+
+class ServerNoticesConfig(Config):
+    """Configuration for the server notices room.
+
+    Attributes:
+        server_notices_mxid (str|None):
+            The MXID to use for server notices.
+            None if server notices are not enabled.
+
+        server_notices_mxid_display_name (str|None):
+            The display name to use for the server notices user.
+            None if server notices are not enabled.
+
+        server_notices_room_name (str|None):
+            The name to use for the server notices room.
+            None if server notices are not enabled.
+    """
+    def __init__(self):
+        super(ServerNoticesConfig, self).__init__()
+        self.server_notices_mxid = None
+        self.server_notices_mxid_display_name = None
+        self.server_notices_room_name = None
+
+    def read_config(self, config):
+        c = config.get("server_notices")
+        if c is None:
+            return
+
+        mxid_localpart = c['system_mxid_localpart']
+        self.server_notices_mxid = UserID(
+            mxid_localpart, self.server_name,
+        ).to_string()
+        self.server_notices_mxid_display_name = c.get(
+            'system_mxid_display_name', 'Server Notices',
+        )
+        # todo: i18n
+        self.server_notices_room_name = c.get('room_name', "Server Notices")
+
+    def default_config(self, **kwargs):
+        return DEFAULT_CONFIG

synapse/handlers/federation.py

@@ -81,6 +81,7 @@ def __init__(self, hs):
         self.pusher_pool = hs.get_pusherpool()
         self.spam_checker = hs.get_spam_checker()
         self.event_creation_handler = hs.get_event_creation_handler()
+        self._server_notices_mxid = hs.config.server_notices_mxid
 
         # When joining a room we need to queue any events for that room up
         self.room_queues = {}
@@ -1180,6 +1181,13 @@ def on_invite_request(self, origin, pdu):
         if not self.is_mine_id(event.state_key):
             raise SynapseError(400, "The invite event must be for this server")
 
+        # block any attempts to invite the server notices mxid
+        if event.state_key == self._server_notices_mxid:
+            raise SynapseError(
+                http_client.FORBIDDEN,
+                "Cannot invite this user",
+            )
+
         event.internal_metadata.outlier = True
         event.internal_metadata.invite_from_remote = True
 

synapse/handlers/register.py

@@ -34,6 +34,11 @@
 class RegistrationHandler(BaseHandler):
 
     def __init__(self, hs):
+        """
+
+        Args:
+            hs (synapse.server.HomeServer):
+        """
         super(RegistrationHandler, self).__init__(hs)
 
         self.auth = hs.get_auth()
@@ -49,6 +54,7 @@ def __init__(self, hs):
         self._generate_user_id_linearizer = Linearizer(
             name="_generate_user_id_linearizer",
         )
+        self._server_notices_mxid = hs.config.server_notices_mxid
 
     @defer.inlineCallbacks
     def check_username(self, localpart, guest_access_token=None,
@@ -338,6 +344,14 @@ def bind_emails(self, user_id, threepidCreds):
             yield identity_handler.bind_threepid(c, user_id)
 
     def check_user_id_not_appservice_exclusive(self, user_id, allowed_appservice=None):
+        # don't allow people to register the server notices mxid
+        if self._server_notices_mxid is not None:
+            if user_id == self._server_notices_mxid:
+                raise SynapseError(
+                    400, "This user ID is reserved.",
+                    errcode=Codes.EXCLUSIVE
+                )
+
         # valid user IDs must not clash with any user ID namespaces claimed by
         # application services.
         services = self.store.get_app_services()

synapse/handlers/room.py

@@ -68,14 +68,23 @@ def __init__(self, hs):
         self.event_creation_handler = hs.get_event_creation_handler()
 
     @defer.inlineCallbacks
-    def create_room(self, requester, config, ratelimit=True):
+    def create_room(self, requester, config, ratelimit=True,
+                    creator_join_profile=None):
         """ Creates a new room.
 
         Args:
             requester (synapse.types.Requester):
                 The user who requested the room creation.
             config (dict) : A dict of configuration options.
             ratelimit (bool): set to False to disable the rate limiter
+
+            creator_join_profile (dict|None):
+                Set to override the displayname and avatar for the creating
+                user in this room. If unset, displayname and avatar will be
+                derived from the user's profile. If set, should contain the
+                values to go in the body of the 'join' event (typically
+                `avatar_url` and/or `displayname`.
+
         Returns:
             Deferred[dict]:
                 a dict containing the keys `room_id` and, if an alias was
@@ -180,7 +189,8 @@ def create_room(self, requester, config, ratelimit=True):
             initial_state=initial_state,
             creation_content=creation_content,
             room_alias=room_alias,
-            power_level_content_override=config.get("power_level_content_override", {})
+            power_level_content_override=config.get("power_level_content_override", {}),
+            creator_join_profile=creator_join_profile,
         )
 
         if "name" in config:
@@ -260,6 +270,7 @@ def _send_events_for_new_room(
             creation_content,
             room_alias,
             power_level_content_override,
+            creator_join_profile,
     ):
         def create(etype, content, **kwargs):
             e = {
@@ -303,6 +314,7 @@ def send(etype, content, **kwargs):
             room_id,
             "join",
             ratelimit=False,
+            content=creator_join_profile,
         )
 
         # We treat the power levels override specially as this needs to be one

synapse/handlers/room_member.py

@@ -17,11 +17,14 @@
 import abc
 import logging
 
+from six.moves import http_client
+
 from signedjson.key import decode_verify_key_bytes
 from signedjson.sign import verify_signed_json
 from twisted.internet import defer
 from unpaddedbase64 import decode_base64
 
+import synapse.server
 import synapse.types
 from synapse.api.constants import (
     EventTypes, Membership,
@@ -46,6 +49,11 @@ class RoomMemberHandler(object):
     __metaclass__ = abc.ABCMeta
 
     def __init__(self, hs):
+        """
+
+        Args:
+            hs (synapse.server.HomeServer):
+        """
         self.hs = hs
         self.store = hs.get_datastore()
         self.auth = hs.get_auth()
@@ -63,6 +71,7 @@ def __init__(self, hs):
 
         self.clock = hs.get_clock()
         self.spam_checker = hs.get_spam_checker()
+        self._server_notices_mxid = self.config.server_notices_mxid
 
     @abc.abstractmethod
     def _remote_join(self, requester, remote_room_hosts, room_id, user, content):
@@ -289,12 +298,36 @@ def _update_membership(
             is_blocked = yield self.store.is_room_blocked(room_id)
             if is_blocked:
                 raise SynapseError(403, "This room has been blocked on this server")
+        else:
+            # we don't allow people to reject invites to, or leave, the
+            # server notice room.
+            is_blocked = yield self._is_server_notice_room(room_id)
+            if is_blocked:
+                raise SynapseError(
+                    http_client.FORBIDDEN,
+                    "You cannot leave this room",
+                )
+
+        if effective_membership_state == Membership.INVITE:
+            # block any attempts to invite the server notices mxid
+            if target.to_string() == self._server_notices_mxid:
+                raise SynapseError(
+                    http_client.FORBIDDEN,
+                    "Cannot invite this user",
+                )
 
-        if effective_membership_state == "invite":
             block_invite = False
-            is_requester_admin = yield self.auth.is_server_admin(
-                requester.user,
-            )
+
+            if (self._server_notices_mxid is not None and
+                    requester.user.to_string() == self._server_notices_mxid):
+                # allow the server notices mxid to send invites
+                is_requester_admin = True
+
+            else:
+                is_requester_admin = yield self.auth.is_server_admin(
+                    requester.user,
+                )
+
             if not is_requester_admin:
                 if self.config.block_non_admin_invites:
                     logger.info(
@@ -844,6 +877,13 @@ def _is_host_in_room(self, current_state_ids):
 
         defer.returnValue(False)
 
+    @defer.inlineCallbacks
+    def _is_server_notice_room(self, room_id):
+        if self._server_notices_mxid is None:
+            defer.returnValue(False)
+        user_ids = yield self.store.get_users_in_room(room_id)
+        defer.returnValue(self._server_notices_mxid in user_ids)
+
 
 class RoomMemberMasterHandler(RoomMemberHandler):
     def __init__(self, hs):

synapse/server.py

@@ -72,6 +72,7 @@
     MediaRepository,
     MediaRepositoryResource,
 )
+from synapse.server_notices.server_notices_manager import ServerNoticesManager
 from synapse.state import StateHandler, StateResolutionHandler
 from synapse.storage import DataStore
 from synapse.streams.events import EventSources
@@ -156,6 +157,7 @@ def build_DEPENDENCY(self)
         'spam_checker',
         'room_member_handler',
         'federation_registry',
+        'server_notices_manager',
     ]
 
     def __init__(self, hostname, **kwargs):
@@ -398,6 +400,9 @@ def build_room_member_handler(self):
     def build_federation_registry(self):
         return FederationHandlerRegistry()
 
+    def build_server_notices_manager(self):
+        return ServerNoticesManager(self)
+
     def remove_pusher(self, app_id, push_key, user_id):
         return self.get_pusherpool().remove_pusher(app_id, push_key, user_id)
 

synapse/server.pyi

@@ -1,4 +1,5 @@
 import synapse.api.auth
+import synapse.config.homeserver
 import synapse.federation.transaction_queue
 import synapse.federation.transport.client
 import synapse.handlers
@@ -8,11 +9,16 @@ import synapse.handlers.device
 import synapse.handlers.e2e_keys
 import synapse.handlers.set_password
 import synapse.rest.media.v1.media_repository
+import synapse.server_notices.server_notices_manager
 import synapse.state
 import synapse.storage
 
 
 class HomeServer(object):
+    @property
+    def config(self) -> synapse.config.homeserver.HomeServerConfig:
+        pass
+
     def get_auth(self) -> synapse.api.auth.Auth:
         pass
 
@@ -43,6 +49,9 @@ class HomeServer(object):
     def get_room_creation_handler(self) -> synapse.handlers.room.RoomCreationHandler:
         pass
 
+    def get_event_creation_handler(self) -> synapse.handlers.message.EventCreationHandler:
+        pass
+
     def get_set_password_handler(self) -> synapse.handlers.set_password.SetPasswordHandler:
         pass
 
@@ -57,3 +66,6 @@ class HomeServer(object):
 
     def get_media_repository(self) -> synapse.rest.media.v1.media_repository.MediaRepository:
         pass
+
+    def get_server_notices_manager(self) -> synapse.server_notices.server_notices_manager.ServerNoticesManager:
+        pass