Move Linux client & common packages into a public repo.

wgengine/winnet/winnet_windows.go

@@ -0,0 +1,26 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package winnet
+
+import (
+	"fmt"
+	"github.com/go-ole/go-ole"
+	"syscall"
+	"unsafe"
+)
+
+func (v *INetworkConnection) GetAdapterId() (string, error) {
+	buf := ole.GUID{}
+	hr, _, _ := syscall.Syscall(
+		v.VTable().GetAdapterId,
+		2,
+		uintptr(unsafe.Pointer(v)),
+		uintptr(unsafe.Pointer(&buf)),
+		0)
+	if hr != 0 {
+		return "", fmt.Errorf("GetAdapterId failed: %08x", hr)
+	}
+	return buf.String(), nil
+}