beta: skip wait for hysteria tcp handshake response

pkg/core/client.go

@@ -209,31 +209,15 @@ func (c *Client) DialTCP(addr string) (net.Conn, error) {
 	if err != nil {
 		return nil, err
 	}
-	// Send request
-	err = struc.Pack(stream, &clientRequest{
-		UDP:  false,
-		Host: host,
-		Port: port,
-	})
-	if err != nil {
-		_ = stream.Close()
-		return nil, err
-	}
-	// Read response
-	var sr serverResponse
-	err = struc.Unpack(stream, &sr)
-	if err != nil {
-		_ = stream.Close()
-		return nil, err
-	}
-	if !sr.OK {
-		_ = stream.Close()
-		return nil, fmt.Errorf("connection rejected: %s", sr.Message)
-	}
 	return &hyTCPConn{
 		Orig:             stream,
 		PseudoLocalAddr:  session.LocalAddr(),
 		PseudoRemoteAddr: session.RemoteAddr(),
+		handshakeRequest: &clientRequest{
+			UDP:  false,
+			Host: host,
+			Port: port,
+		},
 	}, nil
 }
 
@@ -304,13 +288,48 @@ type hyTCPConn struct {
 	Orig             quic.Stream
 	PseudoLocalAddr  net.Addr
 	PseudoRemoteAddr net.Addr
+	// For TCP connections
+	handshakeRead    sync.Once
+	handshakeWrite   sync.Once
+	handshakeRequest *clientRequest
 }
 
 func (w *hyTCPConn) Read(b []byte) (n int, err error) {
+	w.handshakeRead.Do(func() {
+		if w.handshakeRequest == nil {
+			return
+		}
+		defer func() { w.handshakeRequest = nil }()
+		// Read response
+		var sr serverResponse
+		err = struc.Unpack(w.Orig, &sr)
+		if err != nil {
+			_ = w.Close()
+			err = fmt.Errorf("handshake %s read failed: %s", w.PseudoRemoteAddr.String(), err)
+			return
+		}
+		if !sr.OK {
+			_ = w.Close()
+			err = fmt.Errorf("handshake %s connection rejected: %s", w.PseudoRemoteAddr.String(), sr.Message)
+			return
+		}
+	})
 	return w.Orig.Read(b)
 }
 
 func (w *hyTCPConn) Write(b []byte) (n int, err error) {
+	w.handshakeWrite.Do(func() {
+		if w.handshakeRequest == nil {
+			return
+		}
+		// Send request
+		err = struc.Pack(w.Orig, w.handshakeRequest)
+		if err != nil {
+			_ = w.Close()
+			err = fmt.Errorf("handshake %s write failed: %s", w.PseudoRemoteAddr.String(), err)
+			return
+		}
+	})
 	return w.Orig.Write(b)
 }