Merge pull request #689 from matrix-org/erikj/member

Do checks for memberships before creating events

5 files changed, 190 insertions, 152 deletions

diff --git a/synapse/handlers/_base.py b/synapse/handlers/_base.py
index 5eeb7042c6..c77afe7f51 100644
--- a/synapse/handlers/_base.py
+++ b/synapse/handlers/_base.py
@@ -204,20 +204,25 @@ class BaseHandler(object):
             )
 
     @defer.inlineCallbacks
-    def _create_new_client_event(self, builder):
-        latest_ret = yield self.store.get_latest_event_ids_and_hashes_in_room(
-            builder.room_id,
-        )
-
-        if latest_ret:
-            depth = max([d for _, _, d in latest_ret]) + 1
+    def _create_new_client_event(self, builder, prev_event_ids=None):
+        if prev_event_ids:
+            prev_events = yield self.store.add_event_hashes(prev_event_ids)
+            prev_max_depth = yield self.store.get_max_depth_of_events(prev_event_ids)
+            depth = prev_max_depth + 1
         else:
-            depth = 1
+            latest_ret = yield self.store.get_latest_event_ids_and_hashes_in_room(
+                builder.room_id,
+            )
 
-        prev_events = [
-            (event_id, prev_hashes)
-            for event_id, prev_hashes, _ in latest_ret
-        ]
+            if latest_ret:
+                depth = max([d for _, _, d in latest_ret]) + 1
+            else:
+                depth = 1
+
+            prev_events = [
+                (event_id, prev_hashes)
+                for event_id, prev_hashes, _ in latest_ret
+            ]
 
         builder.prev_events = prev_events
         builder.depth = depth
@@ -226,49 +231,6 @@ class BaseHandler(object):
 
         context = yield state_handler.compute_event_context(builder)
 
-        # If we've received an invite over federation, there are no latest
-        # events in the room, because we don't know enough about the graph
-        # fragment we received to treat it like a graph, so the above returned
-        # no relevant events. It may have returned some events (if we have
-        # joined and left the room), but not useful ones, like the invite.
-        if (
-            not self.is_host_in_room(context.current_state) and
-            builder.type == EventTypes.Member
-        ):
-            prev_member_event = yield self.store.get_room_member(
-                builder.sender, builder.room_id
-            )
-
-            # The prev_member_event may already be in context.current_state,
-            # despite us not being present in the room; in particular, if
-            # inviting user, and all other local users, have already left.
-            #
-            # In that case, we have all the information we need, and we don't
-            # want to drop "context" - not least because we may need to handle
-            # the invite locally, which will require us to have the whole
-            # context (not just prev_member_event) to auth it.
-            #
-            context_event_ids = (
-                e.event_id for e in context.current_state.values()
-            )
-
-            if (
-                prev_member_event and
-                prev_member_event.event_id not in context_event_ids
-            ):
-                # The prev_member_event is missing from context, so it must
-                # have arrived over federation and is an outlier. We forcibly
-                # set our context to the invite we received over federation
-                builder.prev_events = (
-                    prev_member_event.event_id,
-                    prev_member_event.prev_events
-                )
-
-                context = yield state_handler.compute_event_context(
-                    builder,
-                    old_state=(prev_member_event,)
-                )
-
         if builder.is_state():
             builder.prev_state = yield self.store.add_event_hashes(
                 context.prev_state_events
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 0bb111d047..10608c0dd9 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -176,7 +176,7 @@ class MessageHandler(BaseHandler):
         defer.returnValue(chunk)
 
     @defer.inlineCallbacks
-    def create_event(self, event_dict, token_id=None, txn_id=None):
+    def create_event(self, event_dict, token_id=None, txn_id=None, prev_event_ids=None):
         """
         Given a dict from a client, create a new event.
 
@@ -187,6 +187,9 @@ class MessageHandler(BaseHandler):
 
         Args:
             event_dict (dict): An entire event
+            token_id (str)
+            txn_id (str)
+            prev_event_ids (list): The prev event ids to use when creating the event
 
         Returns:
             Tuple of created event (FrozenEvent), Context
@@ -225,6 +228,7 @@ class MessageHandler(BaseHandler):
 
         event, context = yield self._create_new_client_event(
             builder=builder,
+            prev_event_ids=prev_event_ids,
         )
         defer.returnValue((event, context))
 
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 01f833c371..2f788a4b1b 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -96,6 +96,82 @@ class RoomMemberHandler(BaseHandler):
                     remotedomains.add(member.domain)
 
     @defer.inlineCallbacks
+    def _local_membership_update(
+        self, requester, target, room_id, membership,
+        prev_event_ids,
+        txn_id=None,
+        ratelimit=True,
+    ):
+        msg_handler = self.hs.get_handlers().message_handler
+
+        content = {"membership": membership}
+        if requester.is_guest:
+            content["kind"] = "guest"
+
+        event, context = yield msg_handler.create_event(
+            {
+                "type": EventTypes.Member,
+                "content": content,
+                "room_id": room_id,
+                "sender": requester.user.to_string(),
+                "state_key": target.to_string(),
+
+                # For backwards compatibility:
+                "membership": membership,
+            },
+            token_id=requester.access_token_id,
+            txn_id=txn_id,
+            prev_event_ids=prev_event_ids,
+        )
+
+        yield self.handle_new_client_event(
+            requester,
+            event,
+            context,
+            extra_users=[target],
+            ratelimit=ratelimit,
+        )
+
+        prev_member_event = context.current_state.get(
+            (EventTypes.Member, target.to_string()),
+            None
+        )
+
+        if event.membership == Membership.JOIN:
+            if not prev_member_event or prev_member_event.membership != Membership.JOIN:
+                # Only fire user_joined_room if the user has acutally joined the
+                # room. Don't bother if the user is just changing their profile
+                # info.
+                yield user_joined_room(self.distributor, target, room_id)
+        elif event.membership == Membership.LEAVE:
+            if prev_member_event and prev_member_event.membership == Membership.JOIN:
+                user_left_room(self.distributor, target, room_id)
+
+    @defer.inlineCallbacks
+    def remote_join(self, remote_room_hosts, room_id, user, content):
+        if len(remote_room_hosts) == 0:
+            raise SynapseError(404, "No known servers")
+
+        # We don't do an auth check if we are doing an invite
+        # join dance for now, since we're kinda implicitly checking
+        # that we are allowed to join when we decide whether or not we
+        # need to do the invite/join dance.
+        yield self.hs.get_handlers().federation_handler.do_invite_join(
+            remote_room_hosts,
+            room_id,
+            user.to_string(),
+            content,
+        )
+        yield user_joined_room(self.distributor, user, room_id)
+
+    def reject_remote_invite(self, user_id, room_id, remote_room_hosts):
+        return self.hs.get_handlers().federation_handler.do_remotely_reject_invite(
+            remote_room_hosts,
+            room_id,
+            user_id
+        )
+
+    @defer.inlineCallbacks
     def update_membership(
             self,
             requester,
@@ -120,28 +196,15 @@ class RoomMemberHandler(BaseHandler):
                 third_party_signed,
             )
 
-        msg_handler = self.hs.get_handlers().message_handler
-
-        content = {"membership": effective_membership_state}
-        if requester.is_guest:
-            content["kind"] = "guest"
+        if not remote_room_hosts:
+            remote_room_hosts = []
 
-        event, context = yield msg_handler.create_event(
-            {
-                "type": EventTypes.Member,
-                "content": content,
-                "room_id": room_id,
-                "sender": requester.user.to_string(),
-                "state_key": target.to_string(),
-
-                # For backwards compatibility:
-                "membership": effective_membership_state,
-            },
-            token_id=requester.access_token_id,
-            txn_id=txn_id,
+        latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
+        current_state = yield self.state_handler.get_current_state(
+            room_id, latest_event_ids=latest_event_ids,
         )
 
-        old_state = context.current_state.get((EventTypes.Member, event.state_key))
+        old_state = current_state.get((EventTypes.Member, target.to_string()))
         old_membership = old_state.content.get("membership") if old_state else None
         if action == "unban" and old_membership != "ban":
             raise SynapseError(
@@ -156,13 +219,58 @@ class RoomMemberHandler(BaseHandler):
                 errcode=Codes.BAD_STATE
             )
 
-        member_handler = self.hs.get_handlers().room_member_handler
-        yield member_handler.send_membership_event(
-            requester,
-            event,
-            context,
+        is_host_in_room = self.is_host_in_room(current_state)
+
+        if effective_membership_state == Membership.JOIN:
+            if requester.is_guest and not self._can_guest_join(current_state):
+                # This should be an auth check, but guests are a local concept,
+                # so don't really fit into the general auth process.
+                raise AuthError(403, "Guest access not allowed")
+
+            if not is_host_in_room:
+                inviter = yield self.get_inviter(target.to_string(), room_id)
+                if inviter and not self.hs.is_mine(inviter):
+                    remote_room_hosts.append(inviter.domain)
+
+                content = {"membership": Membership.JOIN}
+                if requester.is_guest:
+                    content["kind"] = "guest"
+
+                ret = yield self.remote_join(
+                    remote_room_hosts, room_id, target, content
+                )
+                defer.returnValue(ret)
+
+        elif effective_membership_state == Membership.LEAVE:
+            if not is_host_in_room:
+                # perhaps we've been invited
+                inviter = yield self.get_inviter(target.to_string(), room_id)
+                if not inviter:
+                    raise SynapseError(404, "Not a known room")
+
+                if self.hs.is_mine(inviter):
+                    # the inviter was on our server, but has now left. Carry on
+                    # with the normal rejection codepath.
+                    #
+                    # This is a bit of a hack, because the room might still be
+                    # active on other servers.
+                    pass
+                else:
+                    # send the rejection to the inviter's HS.
+                    remote_room_hosts = remote_room_hosts + [inviter.domain]
+                    ret = yield self.reject_remote_invite(
+                        target.to_string(), room_id, remote_room_hosts
+                    )
+                    defer.returnValue(ret)
+
+        yield self._local_membership_update(
+            requester=requester,
+            target=target,
+            room_id=room_id,
+            membership=effective_membership_state,
+            txn_id=txn_id,
             ratelimit=ratelimit,
-            remote_room_hosts=remote_room_hosts,
+            prev_event_ids=latest_event_ids,
         )
 
     @defer.inlineCallbacks
@@ -211,73 +319,19 @@ class RoomMemberHandler(BaseHandler):
         if prev_event is not None:
             return
 
-        action = "send"
-
         if event.membership == Membership.JOIN:
             if requester.is_guest and not self._can_guest_join(context.current_state):
                 # This should be an auth check, but guests are a local concept,
                 # so don't really fit into the general auth process.
                 raise AuthError(403, "Guest access not allowed")
-            do_remote_join_dance, remote_room_hosts = self._should_do_dance(
-                context,
-                (self.get_inviter(event.state_key, context.current_state)),
-                remote_room_hosts,
-            )
-            if do_remote_join_dance:
-                action = "remote_join"
-        elif event.membership == Membership.LEAVE:
-            is_host_in_room = self.is_host_in_room(context.current_state)
-
-            if not is_host_in_room:
-                # perhaps we've been invited
-                inviter = self.get_inviter(
-                    target_user.to_string(), context.current_state
-                )
-                if not inviter:
-                    raise SynapseError(404, "Not a known room")
 
-                if self.hs.is_mine(inviter):
-                    # the inviter was on our server, but has now left. Carry on
-                    # with the normal rejection codepath.
-                    #
-                    # This is a bit of a hack, because the room might still be
-                    # active on other servers.
-                    pass
-                else:
-                    # send the rejection to the inviter's HS.
-                    remote_room_hosts = remote_room_hosts + [inviter.domain]
-                    action = "remote_reject"
-
-        federation_handler = self.hs.get_handlers().federation_handler
-
-        if action == "remote_join":
-            if len(remote_room_hosts) == 0:
-                raise SynapseError(404, "No known servers")
-
-            # We don't do an auth check if we are doing an invite
-            # join dance for now, since we're kinda implicitly checking
-            # that we are allowed to join when we decide whether or not we
-            # need to do the invite/join dance.
-            yield federation_handler.do_invite_join(
-                remote_room_hosts,
-                event.room_id,
-                event.user_id,
-                event.content,
-            )
-        elif action == "remote_reject":
-            yield federation_handler.do_remotely_reject_invite(
-                remote_room_hosts,
-                room_id,
-                event.user_id
-            )
-        else:
-            yield self.handle_new_client_event(
-                requester,
-                event,
-                context,
-                extra_users=[target_user],
-                ratelimit=ratelimit,
-            )
+        yield self.handle_new_client_event(
+            requester,
+            event,
+            context,
+            extra_users=[target_user],
+            ratelimit=ratelimit,
+        )
 
         prev_member_event = context.current_state.get(
             (EventTypes.Member, target_user.to_string()),
@@ -306,11 +360,11 @@ class RoomMemberHandler(BaseHandler):
             and guest_access.content["guest_access"] == "can_join"
         )
 
-    def _should_do_dance(self, context, inviter, room_hosts=None):
+    def _should_do_dance(self, current_state, inviter, room_hosts=None):
         # TODO: Shouldn't this be remote_room_host?
         room_hosts = room_hosts or []
 
-        is_host_in_room = self.is_host_in_room(context.current_state)
+        is_host_in_room = self.is_host_in_room(current_state)
         if is_host_in_room:
             return False, room_hosts
 
@@ -344,11 +398,11 @@ class RoomMemberHandler(BaseHandler):
 
         defer.returnValue((RoomID.from_string(room_id), servers))
 
-    def get_inviter(self, user_id, current_state):
-        prev_state = current_state.get((EventTypes.Member, user_id))
-        if prev_state and prev_state.membership == Membership.INVITE:
-            return UserID.from_string(prev_state.user_id)
-        return None
+    @defer.inlineCallbacks
+    def get_inviter(self, user_id, room_id):
+        invite = yield self.store.get_room_member(user_id=user_id, room_id=room_id)
+        if invite:
+            defer.returnValue(UserID.from_string(invite.sender))
 
     @defer.inlineCallbacks
     def get_joined_rooms_for_user(self, user):
diff --git a/synapse/state.py b/synapse/state.py
index 1bca0f8f78..58211f5feb 100644
--- a/synapse/state.py
+++ b/synapse/state.py
@@ -75,7 +75,8 @@ class StateHandler(object):
         self._state_cache.start()
 
     @defer.inlineCallbacks
-    def get_current_state(self, room_id, event_type=None, state_key=""):
+    def get_current_state(self, room_id, event_type=None, state_key="",
+                          latest_event_ids=None):
         """ Retrieves the current state for the room. This is done by
         calling `get_latest_events_in_room` to get the leading edges of the
         event graph and then resolving any of the state conflicts.
@@ -89,9 +90,10 @@ class StateHandler(object):
         Returns:
             map from (type, state_key) to event
         """
-        event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
+        if not latest_event_ids:
+            latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
 
-        res = yield self.resolve_state_groups(room_id, event_ids)
+        res = yield self.resolve_state_groups(room_id, latest_event_ids)
         state = res[1]
 
         if event_type:
diff --git a/synapse/storage/event_federation.py b/synapse/storage/event_federation.py
index 3489315e0d..0827946207 100644
--- a/synapse/storage/event_federation.py
+++ b/synapse/storage/event_federation.py
@@ -163,6 +163,22 @@ class EventFederationStore(SQLBaseStore):
             room_id,
         )
 
+    @defer.inlineCallbacks
+    def get_max_depth_of_events(self, event_ids):
+        sql = (
+            "SELECT MAX(depth) FROM events WHERE event_id IN (%s)"
+        ) % (",".join(["?"] * len(event_ids)),)
+
+        rows = yield self._execute(
+            "get_max_depth_of_events", None,
+            sql, *event_ids
+        )
+
+        if rows:
+            defer.returnValue(rows[0][0])
+        else:
+            defer.returnValue(1)
+
     def _get_min_depth_interaction(self, txn, room_id):
         min_depth = self._simple_select_one_onecol_txn(
             txn,