Remove `origin` field from PDUs (#2737)

This nukes the `origin` field from PDUs as per
matrix-org/matrix-spec#998, matrix-org/gomatrixserverlib#341.

4 files changed, 32 insertions, 17 deletions

diff --git a/roomserver/internal/input/input_events.go b/roomserver/internal/input/input_events.go
index 29af649a..01fd6201 100644
--- a/roomserver/internal/input/input_events.go
+++ b/roomserver/internal/input/input_events.go
@@ -118,6 +118,10 @@ func (r *Inputer) processRoomEvent(
 	if roomInfo == nil && !isCreateEvent {
 		return fmt.Errorf("room %s does not exist for event %s", event.RoomID(), event.EventID())
 	}
+	_, senderDomain, err := gomatrixserverlib.SplitID('@', event.Sender())
+	if err != nil {
+		return fmt.Errorf("event has invalid sender %q", input.Event.Sender())
+	}
 
 	// If we already know about this outlier and it hasn't been rejected
 	// then we won't attempt to reprocess it. If it was rejected or has now
@@ -145,7 +149,8 @@ func (r *Inputer) processRoomEvent(
 	var missingAuth, missingPrev bool
 	serverRes := &fedapi.QueryJoinedHostServerNamesInRoomResponse{}
 	if !isCreateEvent {
-		missingAuthIDs, missingPrevIDs, err := r.DB.MissingAuthPrevEvents(ctx, event)
+		var missingAuthIDs, missingPrevIDs []string
+		missingAuthIDs, missingPrevIDs, err = r.DB.MissingAuthPrevEvents(ctx, event)
 		if err != nil {
 			return fmt.Errorf("updater.MissingAuthPrevEvents: %w", err)
 		}
@@ -158,7 +163,7 @@ func (r *Inputer) processRoomEvent(
 			RoomID:      event.RoomID(),
 			ExcludeSelf: true,
 		}
-		if err := r.FSAPI.QueryJoinedHostServerNamesInRoom(ctx, serverReq, serverRes); err != nil {
+		if err = r.FSAPI.QueryJoinedHostServerNamesInRoom(ctx, serverReq, serverRes); err != nil {
 			return fmt.Errorf("r.FSAPI.QueryJoinedHostServerNamesInRoom: %w", err)
 		}
 		// Sort all of the servers into a map so that we can randomise
@@ -173,9 +178,9 @@ func (r *Inputer) processRoomEvent(
 			serverRes.ServerNames = append(serverRes.ServerNames, input.Origin)
 			delete(servers, input.Origin)
 		}
-		if origin := event.Origin(); origin != input.Origin {
-			serverRes.ServerNames = append(serverRes.ServerNames, origin)
-			delete(servers, origin)
+		if senderDomain != input.Origin {
+			serverRes.ServerNames = append(serverRes.ServerNames, senderDomain)
+			delete(servers, senderDomain)
 		}
 		for server := range servers {
 			serverRes.ServerNames = append(serverRes.ServerNames, server)
@@ -188,7 +193,7 @@ func (r *Inputer) processRoomEvent(
 	isRejected := false
 	authEvents := gomatrixserverlib.NewAuthEvents(nil)
 	knownEvents := map[string]*types.Event{}
-	if err := r.fetchAuthEvents(ctx, logger, headered, &authEvents, knownEvents, serverRes.ServerNames); err != nil {
+	if err = r.fetchAuthEvents(ctx, logger, headered, &authEvents, knownEvents, serverRes.ServerNames); err != nil {
 		return fmt.Errorf("r.fetchAuthEvents: %w", err)
 	}
 
@@ -231,7 +236,6 @@ func (r *Inputer) processRoomEvent(
 	if input.Kind == api.KindNew {
 		// Check that the event passes authentication checks based on the
 		// current room state.
-		var err error
 		softfail, err = helpers.CheckForSoftFail(ctx, r.DB, headered, input.StateEventIDs)
 		if err != nil {
 			logger.WithError(err).Warn("Error authing soft-failed event")
@@ -265,7 +269,8 @@ func (r *Inputer) processRoomEvent(
 				hadEvents:  map[string]bool{},
 				haveEvents: map[string]*gomatrixserverlib.Event{},
 			}
-			if stateSnapshot, err := missingState.processEventWithMissingState(ctx, event, headered.RoomVersion); err != nil {
+			var stateSnapshot *parsedRespState
+			if stateSnapshot, err = missingState.processEventWithMissingState(ctx, event, headered.RoomVersion); err != nil {
 				// Something went wrong with retrieving the missing state, so we can't
 				// really do anything with the event other than reject it at this point.
 				isRejected = true
@@ -302,7 +307,6 @@ func (r *Inputer) processRoomEvent(
 	// burning CPU time.
 	historyVisibility := gomatrixserverlib.HistoryVisibilityShared // Default to shared.
 	if input.Kind != api.KindOutlier && rejectionErr == nil && !isRejected {
-		var err error
 		historyVisibility, rejectionErr, err = r.processStateBefore(ctx, input, missingPrev)
 		if err != nil {
 			return fmt.Errorf("r.processStateBefore: %w", err)
diff --git a/roomserver/internal/perform/perform_backfill.go b/roomserver/internal/perform/perform_backfill.go
index 51c66415..69a07573 100644
--- a/roomserver/internal/perform/perform_backfill.go
+++ b/roomserver/internal/perform/perform_backfill.go
@@ -468,7 +468,9 @@ FindSuccessor:
 	// Store the server names in a temporary map to avoid duplicates.
 	serverSet := make(map[gomatrixserverlib.ServerName]bool)
 	for _, event := range memberEvents {
-		serverSet[event.Origin()] = true
+		if _, senderDomain, err := gomatrixserverlib.SplitID('@', event.Sender()); err == nil {
+			serverSet[senderDomain] = true
+		}
 	}
 	var servers []gomatrixserverlib.ServerName
 	for server := range serverSet {
diff --git a/roomserver/internal/perform/perform_invite.go b/roomserver/internal/perform/perform_invite.go
index 483e78c3..3fbdf332 100644
--- a/roomserver/internal/perform/perform_invite.go
+++ b/roomserver/internal/perform/perform_invite.go
@@ -50,6 +50,10 @@ func (r *Inviter) PerformInvite(
 	if event.StateKey() == nil {
 		return nil, fmt.Errorf("invite must be a state event")
 	}
+	_, senderDomain, err := gomatrixserverlib.SplitID('@', event.Sender())
+	if err != nil {
+		return nil, fmt.Errorf("sender %q is invalid", event.Sender())
+	}
 
 	roomID := event.RoomID()
 	targetUserID := *event.StateKey()
@@ -67,7 +71,7 @@ func (r *Inviter) PerformInvite(
 		return nil, nil
 	}
 	isTargetLocal := domain == r.Cfg.Matrix.ServerName
-	isOriginLocal := event.Origin() == r.Cfg.Matrix.ServerName
+	isOriginLocal := senderDomain == r.Cfg.Matrix.ServerName
 	if !isOriginLocal && !isTargetLocal {
 		res.Error = &api.PerformError{
 			Code: api.PerformErrorBadRequest,
@@ -235,7 +239,7 @@ func (r *Inviter) PerformInvite(
 			{
 				Kind:         api.KindNew,
 				Event:        event,
-				Origin:       event.Origin(),
+				Origin:       senderDomain,
 				SendAsServer: req.SendAsServer,
 			},
 		},
diff --git a/roomserver/internal/perform/perform_leave.go b/roomserver/internal/perform/perform_leave.go
index 036404cd..ada3aab0 100644
--- a/roomserver/internal/perform/perform_leave.go
+++ b/roomserver/internal/perform/perform_leave.go
@@ -81,12 +81,11 @@ func (r *Leaver) performLeaveRoomByID(
 	// that.
 	isInvitePending, senderUser, eventID, err := helpers.IsInvitePending(ctx, r.DB, req.RoomID, req.UserID)
 	if err == nil && isInvitePending {
-		var host gomatrixserverlib.ServerName
-		_, host, err = gomatrixserverlib.SplitID('@', senderUser)
-		if err != nil {
+		_, senderDomain, serr := gomatrixserverlib.SplitID('@', senderUser)
+		if serr != nil {
 			return nil, fmt.Errorf("sender %q is invalid", senderUser)
 		}
-		if host != r.Cfg.Matrix.ServerName {
+		if senderDomain != r.Cfg.Matrix.ServerName {
 			return r.performFederatedRejectInvite(ctx, req, res, senderUser, eventID)
 		}
 		// check that this is not a "server notice room"
@@ -172,6 +171,12 @@ func (r *Leaver) performLeaveRoomByID(
 		return nil, fmt.Errorf("eventutil.BuildEvent: %w", err)
 	}
 
+	// Get the sender domain.
+	_, senderDomain, serr := gomatrixserverlib.SplitID('@', event.Sender())
+	if serr != nil {
+		return nil, fmt.Errorf("sender %q is invalid", event.Sender())
+	}
+
 	// Give our leave event to the roomserver input stream. The
 	// roomserver will process the membership change and notify
 	// downstream automatically.
@@ -180,7 +185,7 @@ func (r *Leaver) performLeaveRoomByID(
 			{
 				Kind:         api.KindNew,
 				Event:        event.Headered(buildRes.RoomVersion),
-				Origin:       event.Origin(),
+				Origin:       senderDomain,
 				SendAsServer: string(r.Cfg.Matrix.ServerName),
 			},
 		},