Send presence to joined hosts only (#2858)

Send presence events only to rooms the user is participating, not all
servers we know about.
Should fix #2752

federationapi/consumers/presence.go

@@ -22,6 +22,7 @@ import (
 	"github.com/matrix-org/dendrite/federationapi/queue"
 	"github.com/matrix-org/dendrite/federationapi/storage"
 	fedTypes "github.com/matrix-org/dendrite/federationapi/types"
+	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/setup/config"
 	"github.com/matrix-org/dendrite/setup/jetstream"
 	"github.com/matrix-org/dendrite/setup/process"
@@ -39,6 +40,7 @@ type OutputPresenceConsumer struct {
 	db                      storage.Database
 	queues                  *queue.OutgoingQueues
 	isLocalServerName       func(gomatrixserverlib.ServerName) bool
+	rsAPI                   roomserverAPI.FederationRoomserverAPI
 	topic                   string
 	outboundPresenceEnabled bool
 }
@@ -50,6 +52,7 @@ func NewOutputPresenceConsumer(
 	js nats.JetStreamContext,
 	queues *queue.OutgoingQueues,
 	store storage.Database,
+	rsAPI roomserverAPI.FederationRoomserverAPI,
 ) *OutputPresenceConsumer {
 	return &OutputPresenceConsumer{
 		ctx:                     process.Context(),
@@ -60,6 +63,7 @@ func NewOutputPresenceConsumer(
 		durable:                 cfg.Matrix.JetStream.Durable("FederationAPIPresenceConsumer"),
 		topic:                   cfg.Matrix.JetStream.Prefixed(jetstream.OutputPresenceEvent),
 		outboundPresenceEnabled: cfg.Matrix.Presence.EnableOutbound,
+		rsAPI:                   rsAPI,
 	}
 }
 
@@ -89,6 +93,16 @@ func (t *OutputPresenceConsumer) onMessage(ctx context.Context, msgs []*nats.Msg
 		return true
 	}
 
+	var queryRes roomserverAPI.QueryRoomsForUserResponse
+	err = t.rsAPI.QueryRoomsForUser(t.ctx, &roomserverAPI.QueryRoomsForUserRequest{
+		UserID:         userID,
+		WantMembership: "join",
+	}, &queryRes)
+	if err != nil {
+		log.WithError(err).Error("failed to calculate joined rooms for user")
+		return true
+	}
+
 	presence := msg.Header.Get("presence")
 
 	ts, err := strconv.Atoi(msg.Header.Get("last_active_ts"))
@@ -96,11 +110,13 @@ func (t *OutputPresenceConsumer) onMessage(ctx context.Context, msgs []*nats.Msg
 		return true
 	}
 
-	joined, err := t.db.GetAllJoinedHosts(ctx)
+	// send this presence to all servers who share rooms with this user.
+	joined, err := t.db.GetJoinedHostsForRooms(t.ctx, queryRes.RoomIDs, true)
 	if err != nil {
 		log.WithError(err).Error("failed to get joined hosts")
 		return true
 	}
+
 	if len(joined) == 0 {
 		return true
 	}

federationapi/federationapi.go

@@ -164,7 +164,7 @@ func NewInternalAPI(
 	}
 
 	presenceConsumer := consumers.NewOutputPresenceConsumer(
-		base.ProcessContext, cfg, js, queues, federationDB,
+		base.ProcessContext, cfg, js, queues, federationDB, rsAPI,
 	)
 	if err = presenceConsumer.Start(); err != nil {
 		logrus.WithError(err).Panic("failed to start presence consumer")

sytest-blacklist

@@ -46,3 +46,6 @@ If a device list update goes missing, the server resyncs on the next one
 # Might be a bug in the test because leaves do appear :-(
 
 Leaves are present in non-gapped incremental syncs
+
+# Below test was passing for the wrong reason, failing correctly since #2858
+New federated private chats get full presence information (SYN-115)

sytest-whitelist

@@ -682,7 +682,6 @@ Presence changes are reported to local room members
 Presence changes are also reported to remote room members
 Presence changes to UNAVAILABLE are reported to local room members
 Presence changes to UNAVAILABLE are reported to remote room members
-New federated private chats get full presence information (SYN-115)
 /upgrade copies >100 power levels to the new room
 Room state after a rejected message event is the same as before
 Room state after a rejected state event is the same as before