fix(multiplayer): bound websocket writes

server/api/events.go

@@ -23,6 +23,7 @@ const (
 	maxWebSocketFrame            = 64 << 10
 	eventQueueCapacity           = 32
 	webSocketIdleLimit           = 2 * time.Minute
+	webSocketWriteLimit          = 10 * time.Second
 	webSocketMessageLimit        = 120
 	webSocketMessageWindow       = time.Minute
 	maxEventConnectionsPerPlayer = 2
@@ -198,7 +199,7 @@ func (s *Service) controlPlaneEvent(w http.ResponseWriter, r *http.Request) {
 				return
 			}
 			writeMu.Lock()
-			err := writeWebSocketFrame(connection, 0x1, payload)
+			err := writeWebSocketFrameWithDeadline(connection, 0x1, payload, webSocketWriteLimit)
 			writeMu.Unlock()
 			if err != nil {
 				return
@@ -284,7 +285,7 @@ func readWebSocketFrames(connection net.Conn, writeMu *sync.Mutex) {
 		}
 		if opcode == 0x9 {
 			writeMu.Lock()
-			_ = writeWebSocketFrame(connection, 0xA, nil)
+			_ = writeWebSocketFrameWithDeadline(connection, 0xA, nil, webSocketWriteLimit)
 			writeMu.Unlock()
 		}
 	}
@@ -381,3 +382,13 @@ func writeWebSocketFrame(connection net.Conn, opcode byte, payload []byte) error
 	_, err := connection.Write(payload)
 	return err
 }
+
+func writeWebSocketFrameWithDeadline(connection net.Conn, opcode byte, payload []byte, timeout time.Duration) error {
+	if timeout <= 0 {
+		return errors.New("invalid websocket write timeout")
+	}
+	if err := connection.SetWriteDeadline(time.Now().Add(timeout)); err != nil {
+		return err
+	}
+	return writeWebSocketFrame(connection, opcode, payload)
+}