change tun from water to wireguard

listener/tun/tun.go

@@ -0,0 +1,57 @@
+package tun
+
+import (
+	"io"
+
+	"github.com/go-gost/core/common/bufpool"
+	"golang.zx2c4.com/wireguard/tun"
+)
+
+const (
+	tunOffsetBytes = 4
+)
+
+type tunDevice struct {
+	dev tun.Device
+}
+
+func (d *tunDevice) Read(p []byte) (n int, err error) {
+	b := bufpool.Get(tunOffsetBytes + 65535)
+	defer bufpool.Put(b)
+
+	n, err = d.dev.Read(*b, tunOffsetBytes)
+	if n <= tunOffsetBytes || err != nil {
+		d.dev.Flush()
+		if n <= tunOffsetBytes {
+			err = io.EOF
+		}
+		return
+	}
+
+	n = copy(p, (*b)[tunOffsetBytes:tunOffsetBytes+n])
+	return
+}
+
+func (d *tunDevice) Write(p []byte) (n int, err error) {
+	b := bufpool.Get(tunOffsetBytes + len(p))
+	defer bufpool.Put(b)
+
+	copy((*b)[tunOffsetBytes:], p)
+	return d.dev.Write(*b, tunOffsetBytes)
+}
+
+func (d *tunDevice) Close() error {
+	return d.dev.Close()
+}
+
+func (l *tunListener) createTunDevice() (dev io.ReadWriteCloser, name string, err error) {
+	ifce, err := tun.CreateTUN(l.md.config.Name, l.md.config.MTU)
+	if err != nil {
+		return
+	}
+
+	dev = &tunDevice{dev: ifce}
+	name, err = ifce.Name()
+
+	return
+}