From 321c2d2f250b0985f7f86051c3c2a5db0a3f7711 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Thu, 12 Dec 2024 20:56:58 +0800
Subject: [PATCH] Fix Read not implemented for windows

---
 tun_windows.go | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/tun_windows.go b/tun_windows.go
index 45d5b00..85e3009 100644
--- a/tun_windows.go
+++ b/tun_windows.go
@@ -345,7 +345,40 @@ func (t *NativeTun) configure() error {
 }
 
 func (t *NativeTun) Read(p []byte) (n int, err error) {
-	return 0, os.ErrInvalid
+	t.running.Add(1)
+	defer t.running.Done()
+retry:
+	if t.close.Load() == 1 {
+		return 0, os.ErrClosed
+	}
+	start := nanotime()
+	shouldSpin := t.rate.current.Load() >= spinloopRateThreshold && uint64(start-t.rate.nextStartTime.Load()) <= rateMeasurementGranularity*2
+	for {
+		if t.close.Load() == 1 {
+			return 0, os.ErrClosed
+		}
+		var packet []byte
+		packet, err = t.session.ReceivePacket()
+		switch err {
+		case nil:
+			n = copy(p, packet)
+			t.session.ReleaseReceivePacket(packet)
+			t.rate.update(uint64(n))
+			return
+		case windows.ERROR_NO_MORE_ITEMS:
+			if !shouldSpin || uint64(nanotime()-start) >= spinloopDuration {
+				windows.WaitForSingleObject(t.readWait, windows.INFINITE)
+				goto retry
+			}
+			procyield(1)
+			continue
+		case windows.ERROR_HANDLE_EOF:
+			return 0, os.ErrClosed
+		case windows.ERROR_INVALID_DATA:
+			return 0, errors.New("send ring corrupt")
+		}
+		return 0, fmt.Errorf("read failed: %w", err)
+	}
 }
 
 func (t *NativeTun) ReadPacket() ([]byte, func(), error) {