From ee02532ab59ec4581e23b8a5e9e4330335c7d1ca Mon Sep 17 00:00:00 2001
From: dyhkwong <50692134+dyhkwong@users.noreply.github.com>
Date: Wed, 20 Aug 2025 02:54:47 +0800
Subject: [PATCH] Fix tlsfragment fallback writeAndWaitAck

---
 common/tlsfragment/conn.go         | 3 +++
 common/tlsfragment/wait_stub.go    | 4 ++++
 common/tlsfragment/wait_windows.go | 3 +++
 3 files changed, 10 insertions(+)

diff --git a/common/tlsfragment/conn.go b/common/tlsfragment/conn.go
index cb29000e..040663bd 100644
--- a/common/tlsfragment/conn.go
+++ b/common/tlsfragment/conn.go
@@ -109,6 +109,9 @@ func (c *Conn) Write(b []byte) (n int, err error) {
 						if err != nil {
 							return
 						}
+						if i != len(splitIndexes) {
+							time.Sleep(c.fallbackDelay)
+						}
 					}
 				}
 			}
diff --git a/common/tlsfragment/wait_stub.go b/common/tlsfragment/wait_stub.go
index 7e451a04..6a1cd889 100644
--- a/common/tlsfragment/wait_stub.go
+++ b/common/tlsfragment/wait_stub.go
@@ -9,6 +9,10 @@ import (
 )
 
 func writeAndWaitAck(ctx context.Context, conn *net.TCPConn, payload []byte, fallbackDelay time.Duration) error {
+	_, err := conn.Write(payload)
+	if err != nil {
+		return err
+	}
 	time.Sleep(fallbackDelay)
 	return nil
 }
diff --git a/common/tlsfragment/wait_windows.go b/common/tlsfragment/wait_windows.go
index 118a204d..49706ca5 100644
--- a/common/tlsfragment/wait_windows.go
+++ b/common/tlsfragment/wait_windows.go
@@ -16,6 +16,9 @@ func writeAndWaitAck(ctx context.Context, conn *net.TCPConn, payload []byte, fal
 	err := winiphlpapi.WriteAndWaitAck(ctx, conn, payload)
 	if err != nil {
 		if errors.Is(err, windows.ERROR_ACCESS_DENIED) {
+			if _, err := conn.Write(payload); err != nil {
+				return err
+			}
 			time.Sleep(fallbackDelay)
 			return nil
 		}