Kill existing subscribers when topic is reserved

server/server.go

@@ -38,11 +38,13 @@ import (
 TODO
 --
 
-- Reservation: Kill existing subscribers when topic is reserved (deadcade)
 - Rate limiting: Sensitive endpoints (account/login/change-password/...)
 - Reservation (UI): Show "This topic is reserved" error message when trying to reserve a reserved topic (Thorben)
 - Reservation (UI): Ask for confirmation when removing reservation (deadcade)
 - Reservation icons (UI)
+- reservation table delete button: dialog "keep or delete messages?"
+- UI: Flickering upgrade banner when logging in
+- JS constants
 
 races:
 - v.user --> see publishSyncEventAsync() test
@@ -63,11 +65,6 @@ Limits & rate limiting:
 Make sure account endpoints make sense for admins
 
 
-UI:
--
-- reservation table delete button: dialog "keep or delete messages?"
-- flicker of upgrade banner
-- JS constants
 Sync:
 	- sync problems with "deleteAfter=0" and "displayName="
 
@@ -359,7 +356,7 @@ func (s *Server) handle(w http.ResponseWriter, r *http.Request) {
 			log.Info("%s Connection closed with HTTP %d (ntfy error %d): %s", logHTTPPrefix(v, r), httpErr.HTTPCode, httpErr.Code, err.Error())
 		}
 		w.Header().Set("Content-Type", "application/json")
-		w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
+		w.Header().Set("Access-Control-Allow-Origin", s.config.AccessControlAllowOrigin) // CORS, allow cross-origin requests
 		w.WriteHeader(httpErr.HTTPCode)
 		io.WriteString(w, httpErr.JSON()+"\n")
 	}
@@ -461,7 +458,7 @@ func (s *Server) handleTopic(w http.ResponseWriter, r *http.Request, v *visitor)
 	unifiedpush := readBoolParam(r, false, "x-unifiedpush", "unifiedpush", "up") // see PUT/POST too!
 	if unifiedpush {
 		w.Header().Set("Content-Type", "application/json")
-		w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
+		w.Header().Set("Access-Control-Allow-Origin", s.config.AccessControlAllowOrigin) // CORS, allow cross-origin requests
 		_, err := io.WriteString(w, `{"unifiedpush":{"version":1}}`+"\n")
 		return err
 	}
@@ -538,7 +535,7 @@ func (s *Server) handleFile(w http.ResponseWriter, r *http.Request, v *visitor)
 		}
 	}
 	w.Header().Set("Content-Length", fmt.Sprintf("%d", stat.Size()))
-	w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
+	w.Header().Set("Access-Control-Allow-Origin", s.config.AccessControlAllowOrigin) // CORS, allow cross-origin requests
 	if r.Method == http.MethodGet {
 		f, err := os.Open(file)
 		if err != nil {
@@ -969,14 +966,16 @@ func (s *Server) handleSubscribeHTTP(w http.ResponseWriter, r *http.Request, v *
 		}
 		return nil
 	}
-	w.Header().Set("Access-Control-Allow-Origin", "*")            // CORS, allow cross-origin requests
-	w.Header().Set("Content-Type", contentType+"; charset=utf-8") // Android/Volley client needs charset!
+	w.Header().Set("Access-Control-Allow-Origin", s.config.AccessControlAllowOrigin) // CORS, allow cross-origin requests
+	w.Header().Set("Content-Type", contentType+"; charset=utf-8")                    // Android/Volley client needs charset!
 	if poll {
 		return s.sendOldMessages(topics, since, scheduled, v, sub)
 	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
 	subscriberIDs := make([]int, 0)
 	for _, t := range topics {
-		subscriberIDs = append(subscriberIDs, t.Subscribe(sub))
+		subscriberIDs = append(subscriberIDs, t.Subscribe(sub, v.MaybeUserID(), cancel))
 	}
 	defer func() {
 		for i, subscriberID := range subscriberIDs {
@@ -991,6 +990,8 @@ func (s *Server) handleSubscribeHTTP(w http.ResponseWriter, r *http.Request, v *
 	}
 	for {
 		select {
+		case <-ctx.Done():
+			return nil
 		case <-r.Context().Done():
 			return nil
 		case <-time.After(s.config.KeepaliveInterval):
@@ -1033,8 +1034,20 @@ func (s *Server) handleSubscribeWS(w http.ResponseWriter, r *http.Request, v *vi
 		return err
 	}
 	defer conn.Close()
+
+	// Subscription connections can be canceled externally, see topic.CancelSubscribers
+	subscriberContext, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// Use errgroup to run WebSocket reader and writer in Go routines
 	var wlock sync.Mutex
-	g, ctx := errgroup.WithContext(context.Background())
+	g, gctx := errgroup.WithContext(context.Background())
+	g.Go(func() error {
+		<-subscriberContext.Done()
+		log.Trace("%s Cancel received, closing subscriber connection", logHTTPPrefix(v, r))
+		conn.Close()
+		return &websocket.CloseError{Code: websocket.CloseNormalClosure, Text: "subscription was canceled"}
+	})
 	g.Go(func() error {
 		pongWait := s.config.KeepaliveInterval + wsPongWait
 		conn.SetReadLimit(wsReadLimit)
@@ -1050,6 +1063,11 @@ func (s *Server) handleSubscribeWS(w http.ResponseWriter, r *http.Request, v *vi
 			if err != nil {
 				return err
 			}
+			select {
+			case <-gctx.Done():
+				return nil
+			default:
+			}
 		}
 	})
 	g.Go(func() error {
@@ -1064,7 +1082,7 @@ func (s *Server) handleSubscribeWS(w http.ResponseWriter, r *http.Request, v *vi
 		}
 		for {
 			select {
-			case <-ctx.Done():
+			case <-gctx.Done():
 				return nil
 			case <-time.After(s.config.KeepaliveInterval):
 				v.Keepalive()
@@ -1085,13 +1103,13 @@ func (s *Server) handleSubscribeWS(w http.ResponseWriter, r *http.Request, v *vi
 		}
 		return conn.WriteJSON(msg)
 	}
-	w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
+	w.Header().Set("Access-Control-Allow-Origin", s.config.AccessControlAllowOrigin) // CORS, allow cross-origin requests
 	if poll {
 		return s.sendOldMessages(topics, since, scheduled, v, sub)
 	}
 	subscriberIDs := make([]int, 0)
 	for _, t := range topics {
-		subscriberIDs = append(subscriberIDs, t.Subscribe(sub))
+		subscriberIDs = append(subscriberIDs, t.Subscribe(sub, v.MaybeUserID(), cancel))
 	}
 	defer func() {
 		for i, subscriberID := range subscriberIDs {
@@ -1193,11 +1211,7 @@ func (s *Server) topicFromPath(path string) (*topic, error) {
 	if len(parts) < 2 {
 		return nil, errHTTPBadRequestTopicInvalid
 	}
-	topics, err := s.topicsFromIDs(parts[1])
-	if err != nil {
-		return nil, err
-	}
-	return topics[0], nil
+	return s.topicFromID(parts[1])
 }
 
 func (s *Server) topicsFromPath(path string) ([]*topic, string, error) {
@@ -1232,6 +1246,14 @@ func (s *Server) topicsFromIDs(ids ...string) ([]*topic, error) {
 	return topics, nil
 }
 
+func (s *Server) topicFromID(id string) (*topic, error) {
+	topics, err := s.topicsFromIDs(id)
+	if err != nil {
+		return nil, err
+	}
+	return topics[0], nil
+}
+
 func (s *Server) execManager() {
 	log.Debug("Manager: Starting")
 	defer log.Debug("Manager: Finished")