Initial support for multiple server names (#2829)

This PR is the first step towards virtual hosting by laying the
groundwork for multiple server names being configured.

7 files changed, 55 insertions, 34 deletions

diff --git a/roomserver/internal/perform/perform_admin.go b/roomserver/internal/perform/perform_admin.go
index cb6b22d3..6a6d51b0 100644
--- a/roomserver/internal/perform/perform_admin.go
+++ b/roomserver/internal/perform/perform_admin.go
@@ -117,6 +117,11 @@ func (r *Admin) PerformAdminEvacuateRoom(
 			PrevEvents: prevEvents,
 		}
 
+		_, senderDomain, err := gomatrixserverlib.SplitID('@', fledglingEvent.Sender)
+		if err != nil {
+			continue
+		}
+
 		if fledglingEvent.Content, err = json.Marshal(memberContent); err != nil {
 			res.Error = &api.PerformError{
 				Code: api.PerformErrorBadRequest,
@@ -146,8 +151,8 @@ func (r *Admin) PerformAdminEvacuateRoom(
 		inputEvents = append(inputEvents, api.InputRoomEvent{
 			Kind:         api.KindNew,
 			Event:        event,
-			Origin:       r.Cfg.Matrix.ServerName,
-			SendAsServer: string(r.Cfg.Matrix.ServerName),
+			Origin:       senderDomain,
+			SendAsServer: string(senderDomain),
 		})
 		res.Affected = append(res.Affected, stateKey)
 		prevEvents = []gomatrixserverlib.EventReference{
@@ -176,7 +181,7 @@ func (r *Admin) PerformAdminEvacuateUser(
 		}
 		return nil
 	}
-	if domain != r.Cfg.Matrix.ServerName {
+	if !r.Cfg.Matrix.IsLocalServerName(domain) {
 		res.Error = &api.PerformError{
 			Code: api.PerformErrorBadRequest,
 			Msg:  "Can only evacuate local users using this endpoint",
diff --git a/roomserver/internal/perform/perform_invite.go b/roomserver/internal/perform/perform_invite.go
index 3fbdf332..f60247cd 100644
--- a/roomserver/internal/perform/perform_invite.go
+++ b/roomserver/internal/perform/perform_invite.go
@@ -70,8 +70,8 @@ func (r *Inviter) PerformInvite(
 		}
 		return nil, nil
 	}
-	isTargetLocal := domain == r.Cfg.Matrix.ServerName
-	isOriginLocal := senderDomain == r.Cfg.Matrix.ServerName
+	isTargetLocal := r.Cfg.Matrix.IsLocalServerName(domain)
+	isOriginLocal := r.Cfg.Matrix.IsLocalServerName(senderDomain)
 	if !isOriginLocal && !isTargetLocal {
 		res.Error = &api.PerformError{
 			Code: api.PerformErrorBadRequest,
diff --git a/roomserver/internal/perform/perform_join.go b/roomserver/internal/perform/perform_join.go
index 262273ff..9d596ab3 100644
--- a/roomserver/internal/perform/perform_join.go
+++ b/roomserver/internal/perform/perform_join.go
@@ -92,7 +92,7 @@ func (r *Joiner) performJoin(
 			Msg:  fmt.Sprintf("Supplied user ID %q in incorrect format", req.UserID),
 		}
 	}
-	if domain != r.Cfg.Matrix.ServerName {
+	if !r.Cfg.Matrix.IsLocalServerName(domain) {
 		return "", "", &rsAPI.PerformError{
 			Code: rsAPI.PerformErrorBadRequest,
 			Msg:  fmt.Sprintf("User %q does not belong to this homeserver", req.UserID),
@@ -124,7 +124,7 @@ func (r *Joiner) performJoinRoomByAlias(
 	// Check if this alias matches our own server configuration. If it
 	// doesn't then we'll need to try a federated join.
 	var roomID string
-	if domain != r.Cfg.Matrix.ServerName {
+	if !r.Cfg.Matrix.IsLocalServerName(domain) {
 		// The alias isn't owned by us, so we will need to try joining using
 		// a remote server.
 		dirReq := fsAPI.PerformDirectoryLookupRequest{
@@ -172,7 +172,7 @@ func (r *Joiner) performJoinRoomByID(
 	// The original client request ?server_name=... may include this HS so filter that out so we
 	// don't attempt to make_join with ourselves
 	for i := 0; i < len(req.ServerNames); i++ {
-		if req.ServerNames[i] == r.Cfg.Matrix.ServerName {
+		if r.Cfg.Matrix.IsLocalServerName(req.ServerNames[i]) {
 			// delete this entry
 			req.ServerNames = append(req.ServerNames[:i], req.ServerNames[i+1:]...)
 			i--
@@ -191,12 +191,19 @@ func (r *Joiner) performJoinRoomByID(
 	// If the server name in the room ID isn't ours then it's a
 	// possible candidate for finding the room via federation. Add
 	// it to the list of servers to try.
-	if domain != r.Cfg.Matrix.ServerName {
+	if !r.Cfg.Matrix.IsLocalServerName(domain) {
 		req.ServerNames = append(req.ServerNames, domain)
 	}
 
 	// Prepare the template for the join event.
 	userID := req.UserID
+	_, userDomain, err := gomatrixserverlib.SplitID('@', userID)
+	if err != nil {
+		return "", "", &rsAPI.PerformError{
+			Code: rsAPI.PerformErrorBadRequest,
+			Msg:  fmt.Sprintf("User ID %q is invalid: %s", userID, err),
+		}
+	}
 	eb := gomatrixserverlib.EventBuilder{
 		Type:     gomatrixserverlib.MRoomMember,
 		Sender:   userID,
@@ -247,7 +254,7 @@ func (r *Joiner) performJoinRoomByID(
 
 		// If we were invited by someone from another server then we can
 		// assume they are in the room so we can join via them.
-		if inviterDomain != r.Cfg.Matrix.ServerName {
+		if !r.Cfg.Matrix.IsLocalServerName(inviterDomain) {
 			req.ServerNames = append(req.ServerNames, inviterDomain)
 			forceFederatedJoin = true
 			memberEvent := gjson.Parse(string(inviteEvent.JSON()))
@@ -300,7 +307,7 @@ func (r *Joiner) performJoinRoomByID(
 					{
 						Kind:         rsAPI.KindNew,
 						Event:        event.Headered(buildRes.RoomVersion),
-						SendAsServer: string(r.Cfg.Matrix.ServerName),
+						SendAsServer: string(userDomain),
 					},
 				},
 			}
@@ -323,7 +330,7 @@ func (r *Joiner) performJoinRoomByID(
 		// The room doesn't exist locally. If the room ID looks like it should
 		// be ours then this probably means that we've nuked our database at
 		// some point.
-		if domain == r.Cfg.Matrix.ServerName {
+		if r.Cfg.Matrix.IsLocalServerName(domain) {
 			// If there are no more server names to try then give up here.
 			// Otherwise we'll try a federated join as normal, since it's quite
 			// possible that the room still exists on other servers.
@@ -348,7 +355,7 @@ func (r *Joiner) performJoinRoomByID(
 	// it will have been overwritten with a room ID by performJoinRoomByAlias.
 	// We should now include this in the response so that the CS API can
 	// return the right room ID.
-	return req.RoomIDOrAlias, r.Cfg.Matrix.ServerName, nil
+	return req.RoomIDOrAlias, userDomain, nil
 }
 
 func (r *Joiner) performFederatedJoinRoomByID(
diff --git a/roomserver/internal/perform/perform_leave.go b/roomserver/internal/perform/perform_leave.go
index 85b65981..49e4b479 100644
--- a/roomserver/internal/perform/perform_leave.go
+++ b/roomserver/internal/perform/perform_leave.go
@@ -52,7 +52,7 @@ func (r *Leaver) PerformLeave(
 	if err != nil {
 		return nil, fmt.Errorf("supplied user ID %q in incorrect format", req.UserID)
 	}
-	if domain != r.Cfg.Matrix.ServerName {
+	if !r.Cfg.Matrix.IsLocalServerName(domain) {
 		return nil, fmt.Errorf("user %q does not belong to this homeserver", req.UserID)
 	}
 	logger := logrus.WithContext(ctx).WithFields(logrus.Fields{
@@ -85,7 +85,7 @@ func (r *Leaver) performLeaveRoomByID(
 		if serr != nil {
 			return nil, fmt.Errorf("sender %q is invalid", senderUser)
 		}
-		if senderDomain != r.Cfg.Matrix.ServerName {
+		if !r.Cfg.Matrix.IsLocalServerName(senderDomain) {
 			return r.performFederatedRejectInvite(ctx, req, res, senderUser, eventID)
 		}
 		// check that this is not a "server notice room"
@@ -186,7 +186,7 @@ func (r *Leaver) performLeaveRoomByID(
 				Kind:         api.KindNew,
 				Event:        event.Headered(buildRes.RoomVersion),
 				Origin:       senderDomain,
-				SendAsServer: string(r.Cfg.Matrix.ServerName),
+				SendAsServer: string(senderDomain),
 			},
 		},
 	}
diff --git a/roomserver/internal/perform/perform_peek.go b/roomserver/internal/perform/perform_peek.go
index 74d87a5b..436d137f 100644
--- a/roomserver/internal/perform/perform_peek.go
+++ b/roomserver/internal/perform/perform_peek.go
@@ -72,7 +72,7 @@ func (r *Peeker) performPeek(
 			Msg:  fmt.Sprintf("Supplied user ID %q in incorrect format", req.UserID),
 		}
 	}
-	if domain != r.Cfg.Matrix.ServerName {
+	if !r.Cfg.Matrix.IsLocalServerName(domain) {
 		return "", &api.PerformError{
 			Code: api.PerformErrorBadRequest,
 			Msg:  fmt.Sprintf("User %q does not belong to this homeserver", req.UserID),
@@ -104,7 +104,7 @@ func (r *Peeker) performPeekRoomByAlias(
 	// Check if this alias matches our own server configuration. If it
 	// doesn't then we'll need to try a federated peek.
 	var roomID string
-	if domain != r.Cfg.Matrix.ServerName {
+	if !r.Cfg.Matrix.IsLocalServerName(domain) {
 		// The alias isn't owned by us, so we will need to try peeking using
 		// a remote server.
 		dirReq := fsAPI.PerformDirectoryLookupRequest{
@@ -154,7 +154,7 @@ func (r *Peeker) performPeekRoomByID(
 
 	// handle federated peeks
 	// FIXME: don't create an outbound peek if we already have one going.
-	if domain != r.Cfg.Matrix.ServerName {
+	if !r.Cfg.Matrix.IsLocalServerName(domain) {
 		// If the server name in the room ID isn't ours then it's a
 		// possible candidate for finding the room via federation. Add
 		// it to the list of servers to try.
diff --git a/roomserver/internal/perform/perform_unpeek.go b/roomserver/internal/perform/perform_unpeek.go
index 49e9067c..0d97da4d 100644
--- a/roomserver/internal/perform/perform_unpeek.go
+++ b/roomserver/internal/perform/perform_unpeek.go
@@ -67,7 +67,7 @@ func (r *Unpeeker) performUnpeek(
 			Msg:  fmt.Sprintf("Supplied user ID %q in incorrect format", req.UserID),
 		}
 	}
-	if domain != r.Cfg.Matrix.ServerName {
+	if !r.Cfg.Matrix.IsLocalServerName(domain) {
 		return &api.PerformError{
 			Code: api.PerformErrorBadRequest,
 			Msg:  fmt.Sprintf("User %q does not belong to this homeserver", req.UserID),
diff --git a/roomserver/internal/perform/perform_upgrade.go b/roomserver/internal/perform/perform_upgrade.go
index d6dc9708..38abe323 100644
--- a/roomserver/internal/perform/perform_upgrade.go
+++ b/roomserver/internal/perform/perform_upgrade.go
@@ -60,6 +60,13 @@ func (r *Upgrader) performRoomUpgrade(
 ) (string, *api.PerformError) {
 	roomID := req.RoomID
 	userID := req.UserID
+	_, userDomain, err := gomatrixserverlib.SplitID('@', userID)
+	if err != nil {
+		return "", &api.PerformError{
+			Code: api.PerformErrorNotAllowed,
+			Msg:  "Error validating the user ID",
+		}
+	}
 	evTime := time.Now()
 
 	// Return an immediate error if the room does not exist
@@ -80,7 +87,7 @@ func (r *Upgrader) performRoomUpgrade(
 
 	// TODO (#267): Check room ID doesn't clash with an existing one, and we
 	//              probably shouldn't be using pseudo-random strings, maybe GUIDs?
-	newRoomID := fmt.Sprintf("!%s:%s", util.RandomString(16), r.Cfg.Matrix.ServerName)
+	newRoomID := fmt.Sprintf("!%s:%s", util.RandomString(16), userDomain)
 
 	// Get the existing room state for the old room.
 	oldRoomReq := &api.QueryLatestEventsAndStateRequest{
@@ -107,12 +114,12 @@ func (r *Upgrader) performRoomUpgrade(
 	}
 
 	// Send the setup events to the new room
-	if pErr = r.sendInitialEvents(ctx, evTime, userID, newRoomID, string(req.RoomVersion), eventsToMake); pErr != nil {
+	if pErr = r.sendInitialEvents(ctx, evTime, userID, userDomain, newRoomID, string(req.RoomVersion), eventsToMake); pErr != nil {
 		return "", pErr
 	}
 
 	// 5. Send the tombstone event to the old room
-	if pErr = r.sendHeaderedEvent(ctx, tombstoneEvent, string(r.Cfg.Matrix.ServerName)); pErr != nil {
+	if pErr = r.sendHeaderedEvent(ctx, userDomain, tombstoneEvent, string(userDomain)); pErr != nil {
 		return "", pErr
 	}
 
@@ -122,7 +129,7 @@ func (r *Upgrader) performRoomUpgrade(
 	}
 
 	// If the old room had a canonical alias event, it should be deleted in the old room
-	if pErr = r.clearOldCanonicalAliasEvent(ctx, oldRoomRes, evTime, userID, roomID); pErr != nil {
+	if pErr = r.clearOldCanonicalAliasEvent(ctx, oldRoomRes, evTime, userID, userDomain, roomID); pErr != nil {
 		return "", pErr
 	}
 
@@ -132,7 +139,7 @@ func (r *Upgrader) performRoomUpgrade(
 	}
 
 	// 6. Restrict power levels in the old room
-	if pErr = r.restrictOldRoomPowerLevels(ctx, evTime, userID, roomID); pErr != nil {
+	if pErr = r.restrictOldRoomPowerLevels(ctx, evTime, userID, userDomain, roomID); pErr != nil {
 		return "", pErr
 	}
 
@@ -154,7 +161,7 @@ func (r *Upgrader) getRoomPowerLevels(ctx context.Context, roomID string) (*goma
 	return powerLevelContent, nil
 }
 
-func (r *Upgrader) restrictOldRoomPowerLevels(ctx context.Context, evTime time.Time, userID, roomID string) *api.PerformError {
+func (r *Upgrader) restrictOldRoomPowerLevels(ctx context.Context, evTime time.Time, userID string, userDomain gomatrixserverlib.ServerName, roomID string) *api.PerformError {
 	restrictedPowerLevelContent, pErr := r.getRoomPowerLevels(ctx, roomID)
 	if pErr != nil {
 		return pErr
@@ -183,7 +190,7 @@ func (r *Upgrader) restrictOldRoomPowerLevels(ctx context.Context, evTime time.T
 			return resErr
 		}
 	} else {
-		if resErr = r.sendHeaderedEvent(ctx, restrictedPowerLevelsHeadered, api.DoNotSendToOtherServers); resErr != nil {
+		if resErr = r.sendHeaderedEvent(ctx, userDomain, restrictedPowerLevelsHeadered, api.DoNotSendToOtherServers); resErr != nil {
 			return resErr
 		}
 	}
@@ -223,7 +230,7 @@ func moveLocalAliases(ctx context.Context,
 	return nil
 }
 
-func (r *Upgrader) clearOldCanonicalAliasEvent(ctx context.Context, oldRoom *api.QueryLatestEventsAndStateResponse, evTime time.Time, userID, roomID string) *api.PerformError {
+func (r *Upgrader) clearOldCanonicalAliasEvent(ctx context.Context, oldRoom *api.QueryLatestEventsAndStateResponse, evTime time.Time, userID string, userDomain gomatrixserverlib.ServerName, roomID string) *api.PerformError {
 	for _, event := range oldRoom.StateEvents {
 		if event.Type() != gomatrixserverlib.MRoomCanonicalAlias || !event.StateKeyEquals("") {
 			continue
@@ -254,7 +261,7 @@ func (r *Upgrader) clearOldCanonicalAliasEvent(ctx context.Context, oldRoom *api
 			return resErr
 		}
 	} else {
-		if resErr = r.sendHeaderedEvent(ctx, emptyCanonicalAliasEvent, api.DoNotSendToOtherServers); resErr != nil {
+		if resErr = r.sendHeaderedEvent(ctx, userDomain, emptyCanonicalAliasEvent, api.DoNotSendToOtherServers); resErr != nil {
 			return resErr
 		}
 	}
@@ -495,7 +502,7 @@ func (r *Upgrader) generateInitialEvents(ctx context.Context, oldRoom *api.Query
 	return eventsToMake, nil
 }
 
-func (r *Upgrader) sendInitialEvents(ctx context.Context, evTime time.Time, userID, newRoomID, newVersion string, eventsToMake []fledglingEvent) *api.PerformError {
+func (r *Upgrader) sendInitialEvents(ctx context.Context, evTime time.Time, userID string, userDomain gomatrixserverlib.ServerName, newRoomID, newVersion string, eventsToMake []fledglingEvent) *api.PerformError {
 	var err error
 	var builtEvents []*gomatrixserverlib.HeaderedEvent
 	authEvents := gomatrixserverlib.NewAuthEvents(nil)
@@ -519,7 +526,7 @@ func (r *Upgrader) sendInitialEvents(ctx context.Context, evTime time.Time, user
 			builder.PrevEvents = []gomatrixserverlib.EventReference{builtEvents[i-1].EventReference()}
 		}
 		var event *gomatrixserverlib.Event
-		event, err = r.buildEvent(&builder, &authEvents, evTime, gomatrixserverlib.RoomVersion(newVersion))
+		event, err = r.buildEvent(&builder, userDomain, &authEvents, evTime, gomatrixserverlib.RoomVersion(newVersion))
 		if err != nil {
 			return &api.PerformError{
 				Msg: fmt.Sprintf("Failed to build new %q event: %s", builder.Type, err),
@@ -547,7 +554,7 @@ func (r *Upgrader) sendInitialEvents(ctx context.Context, evTime time.Time, user
 		inputs = append(inputs, api.InputRoomEvent{
 			Kind:         api.KindNew,
 			Event:        event,
-			Origin:       r.Cfg.Matrix.ServerName,
+			Origin:       userDomain,
 			SendAsServer: api.DoNotSendToOtherServers,
 		})
 	}
@@ -668,6 +675,7 @@ func createTemporaryPowerLevels(powerLevelContent *gomatrixserverlib.PowerLevelC
 
 func (r *Upgrader) sendHeaderedEvent(
 	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
 	headeredEvent *gomatrixserverlib.HeaderedEvent,
 	sendAsServer string,
 ) *api.PerformError {
@@ -675,7 +683,7 @@ func (r *Upgrader) sendHeaderedEvent(
 	inputs = append(inputs, api.InputRoomEvent{
 		Kind:         api.KindNew,
 		Event:        headeredEvent,
-		Origin:       r.Cfg.Matrix.ServerName,
+		Origin:       serverName,
 		SendAsServer: sendAsServer,
 	})
 	if err := api.SendInputRoomEvents(ctx, r.URSAPI, inputs, false); err != nil {
@@ -689,6 +697,7 @@ func (r *Upgrader) sendHeaderedEvent(
 
 func (r *Upgrader) buildEvent(
 	builder *gomatrixserverlib.EventBuilder,
+	serverName gomatrixserverlib.ServerName,
 	provider gomatrixserverlib.AuthEventProvider,
 	evTime time.Time,
 	roomVersion gomatrixserverlib.RoomVersion,
@@ -703,7 +712,7 @@ func (r *Upgrader) buildEvent(
 	}
 	builder.AuthEvents = refs
 	event, err := builder.Build(
-		evTime, r.Cfg.Matrix.ServerName, r.Cfg.Matrix.KeyID,
+		evTime, serverName, r.Cfg.Matrix.KeyID,
 		r.Cfg.Matrix.PrivateKey, roomVersion,
 	)
 	if err != nil {