Pass through content, try to handle multiple server names

clientapi/routing/joinroom.go

@@ -19,6 +19,7 @@ import (
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
 	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
+	"github.com/matrix-org/dendrite/clientapi/httputil"
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	"github.com/matrix-org/dendrite/clientapi/producers"
 	"github.com/matrix-org/dendrite/common/config"
@@ -40,12 +41,21 @@ func JoinRoomByIDOrAlias(
 	keyRing gomatrixserverlib.KeyRing, // nolint:unparam
 	accountDB accounts.Database, // nolint:unparam
 ) util.JSONResponse {
+	// Prepare to ask the roomserver to perform the room join.
 	joinReq := roomserverAPI.PerformJoinRequest{
 		RoomIDOrAlias: roomIDOrAlias,
 		UserID:        device.UserID,
-		Content:       nil,
 	}
 	joinRes := roomserverAPI.PerformJoinResponse{}
+
+	// If content was provided in the request then incude that
+	// in the request. It'll get used as a part of the membership
+	// event content.
+	if err := httputil.UnmarshalJSONRequest(req, &joinReq.Content); err != nil {
+		return *err
+	}
+
+	// Ask the roomserver to perform the join.
 	if err := rsAPI.PerformJoin(req.Context(), &joinReq, &joinRes); err != nil {
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,

roomserver/api/perform.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	commonHTTP "github.com/matrix-org/dendrite/common/http"
+	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/opentracing/opentracing-go"
 )
 
@@ -19,6 +20,7 @@ type PerformJoinRequest struct {
 	RoomIDOrAlias string                         `json:"room_id_or_alias"`
 	UserID        string                         `json:"user_id"`
 	Content       map[string]interface{}         `json:"content"`
+	ServerNames   []gomatrixserverlib.ServerName `json:"server_names"`
 }
 
 type PerformJoinResponse struct {

roomserver/internal/perform_join.go

@@ -10,6 +10,7 @@ import (
 	fsAPI "github.com/matrix-org/dendrite/federationsender/api"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
 )
 
 // WriteOutputEvents implements OutputRoomEventWriter
@@ -39,6 +40,13 @@ func (r *RoomserverInternalAPI) performJoinRoomByAlias(
 	req *api.PerformJoinRequest,
 	res *api.PerformJoinResponse,
 ) error {
+	// Get the domain part of the room alias.
+	_, domain, err := gomatrixserverlib.SplitID('#', req.RoomIDOrAlias)
+	if err != nil {
+		return fmt.Errorf("supplied room alias %q in incorrect format", req.RoomIDOrAlias)
+	}
+	req.ServerNames = append(req.ServerNames, domain)
+
 	// Look up if we know this room alias.
 	roomID, err := r.DB.GetRoomIDForAlias(ctx, req.RoomIDOrAlias)
 	if err != nil {
@@ -50,11 +58,20 @@ func (r *RoomserverInternalAPI) performJoinRoomByAlias(
 	return r.performJoinRoomByID(ctx, req, res)
 }
 
+// TODO: Break this function up a bit
+// nolint:gocyclo
 func (r *RoomserverInternalAPI) performJoinRoomByID(
 	ctx context.Context,
 	req *api.PerformJoinRequest,
-	res *api.PerformJoinResponse,
+	res *api.PerformJoinResponse, // nolint:unparam
 ) error {
+	// Get the domain part of the room ID.
+	_, domain, err := gomatrixserverlib.SplitID('#', req.RoomIDOrAlias)
+	if err != nil {
+		return fmt.Errorf("supplied room alias %q in incorrect format", req.RoomIDOrAlias)
+	}
+	req.ServerNames = append(req.ServerNames, domain)
+
 	// Prepare the template for the join event.
 	userID := req.UserID
 	eb := gomatrixserverlib.EventBuilder{
@@ -64,18 +81,18 @@ func (r *RoomserverInternalAPI) performJoinRoomByID(
 		RoomID:   req.RoomIDOrAlias,
 		Redacts:  "",
 	}
-	if err := eb.SetUnsigned(struct{}{}); err != nil {
+	if err = eb.SetUnsigned(struct{}{}); err != nil {
 		return fmt.Errorf("eb.SetUnsigned: %w", err)
 	}
 
-	// It is possible for the requestoto include some "content" for the
+	// It is possible for the request to include some "content" for the
 	// event. We'll always overwrite the "membership" key, but the rest,
 	// like "display_name" or "avatar_url", will be kept if supplied.
 	if req.Content == nil {
 		req.Content = map[string]interface{}{}
 	}
 	req.Content["membership"] = "join"
-	if err := eb.SetContent(req.Content); err != nil {
+	if err = eb.SetContent(req.Content); err != nil {
 		return fmt.Errorf("eb.SetContent: %w", err)
 	}
 
@@ -124,18 +141,35 @@ func (r *RoomserverInternalAPI) performJoinRoomByID(
 			return fmt.Errorf("error trying to join %q room: %w", req.RoomIDOrAlias, derr)
 		}
 
+		// Try joining by all of the supplied server names.
+		// TODO: Update the FS API so that it accepts a list of server names and
+		// does this bit by itself.
+		joined := false
+		for _, serverName := range req.ServerNames {
 			// Otherwise, if we've reached this point, the room isn't a local room
 			// and we should ask the federation sender to try and join for us.
 			fedReq := fsAPI.PerformJoinRequest{
 				RoomID:     req.RoomIDOrAlias, // the room ID to try and join
 				UserID:     req.UserID,        // the user ID joining the room
-			ServerName: domain,            // the server to try joining with
+				ServerName: serverName,        // the server to try joining with
 				Content:    req.Content,       // the membership event content
 			}
 			fedRes := fsAPI.PerformJoinResponse{}
 			err = r.fsAPI.PerformJoin(ctx, &fedReq, &fedRes)
 			if err != nil {
-			return fmt.Errorf("error joining federated room %q: %w", req.RoomIDOrAlias, err)
+				logrus.WithError(err).Errorf("error joining federated room %q", req.RoomIDOrAlias)
+				continue
+			}
+			joined = true
+		}
+
+		// If we didn't successfully join the room using any of the supplied
+		// servers then return an error saying such.
+		if !joined {
+			return fmt.Errorf(
+				"failed to join %q using %d server(s)",
+				req.RoomIDOrAlias, len(req.ServerNames),
+			)
 		}
 
 	default: