rpc: set pong read deadline (#23556)

This PR adds a 30s timeout for the remote part to answer a ping message, thus detecting (silent) disconnnects

rpc/websocket.go

@@ -37,6 +37,7 @@ const (
 	wsWriteBuffer      = 1024
 	wsPingInterval     = 60 * time.Second
 	wsPingWriteTimeout = 5 * time.Second
+	wsPongTimeout      = 30 * time.Second
 	wsMessageSizeLimit = 15 * 1024 * 1024
 )
 
@@ -241,6 +242,10 @@ type websocketCodec struct {
 
 func newWebsocketCodec(conn *websocket.Conn) ServerCodec {
 	conn.SetReadLimit(wsMessageSizeLimit)
+	conn.SetPongHandler(func(appData string) error {
+		conn.SetReadDeadline(time.Time{})
+		return nil
+	})
 	wc := &websocketCodec{
 		jsonCodec: NewFuncCodec(conn, conn.WriteJSON, conn.ReadJSON).(*jsonCodec),
 		conn:      conn,
@@ -287,6 +292,7 @@ func (wc *websocketCodec) pingLoop() {
 			wc.jsonCodec.encMu.Lock()
 			wc.conn.SetWriteDeadline(time.Now().Add(wsPingWriteTimeout))
 			wc.conn.WriteMessage(websocket.PingMessage, nil)
+			wc.conn.SetReadDeadline(time.Now().Add(wsPongTimeout))
 			wc.jsonCodec.encMu.Unlock()
 			timer.Reset(wsPingInterval)
 		}