From 49e4afd5c79ec92127c83e9601f9b050d6725e56 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Tue, 19 May 2026 20:38:06 +0800
Subject: [PATCH] Handle existing Wintun adapter on restart

---
 tun_windows.go | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tun_windows.go b/tun_windows.go
index 54e7395..d00d51d 100644
--- a/tun_windows.go
+++ b/tun_windows.go
@@ -43,7 +43,14 @@ func New(options Options) (WinTun, error) {
 	}
 	adapter, err := wintun.CreateAdapter(options.Name, TunnelType, generateGUIDByDeviceName(options.Name))
 	if err != nil {
-		return nil, err
+		if !errors.Is(err, os.ErrExist) {
+			return nil, err
+		}
+		createErr := err
+		adapter, err = wintun.OpenAdapter(options.Name)
+		if err != nil {
+			return nil, E.Errors(E.Cause(createErr, "create adapter"), E.Cause(err, "open existing adapter"))
+		}
 	}
 	nativeTun := &NativeTun{
 		adapter: adapter,