Load wintun.dll

iface/dll.go

@@ -0,0 +1,61 @@
+//go:build windows
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2021 WireGuard LLC. All Rights Reserved.
+ */
+
+package iface
+
+import (
+	"fmt"
+	"golang.zx2c4.com/wireguard/windows/driver/memmod"
+	"sync"
+	"sync/atomic"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+type lazyDLL struct {
+	Name   string
+	Base   windows.Handle
+	mu     sync.Mutex
+	module *memmod.Module
+	onLoad func(d *lazyDLL)
+}
+
+func (d *lazyDLL) Load() error {
+	if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&d.module))) != nil {
+		return nil
+	}
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if d.module != nil {
+		return nil
+	}
+
+	const ourModule windows.Handle = 0
+	resInfo, err := windows.FindResource(ourModule, d.Name, windows.RT_RCDATA)
+	if err != nil {
+		return fmt.Errorf("Unable to find \"%v\" RCDATA resource: %w", d.Name, err)
+	}
+	data, err := windows.LoadResourceData(ourModule, resInfo)
+	if err != nil {
+		return fmt.Errorf("Unable to load resource: %w", err)
+	}
+	module, err := memmod.LoadLibrary(data)
+	if err != nil {
+		return fmt.Errorf("Unable to load library: %w", err)
+	}
+	d.Base = windows.Handle(module.BaseAddr())
+
+	atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&d.module)), unsafe.Pointer(module))
+	if d.onLoad != nil {
+		d.onLoad(d)
+	}
+	return nil
+}
+func newLazyDLL(name string, onLoad func(d *lazyDLL)) *lazyDLL {
+	return &lazyDLL{Name: name, onLoad: onLoad}
+}

iface/tun_windows.go

@@ -37,11 +37,17 @@ func (c *tunDevice) Create() error {
 
 // createWithUserspace Creates a new WireGuard interface, using wireguard-go userspace implementation
 func (c *tunDevice) createWithUserspace() (NetInterface, error) {
-	dll := windows.NewLazyDLL("wintun.dll")
+
+	dll := newLazyDLL("wintun.dll", func(d *lazyDLL) {
+
+	})
+
 	err := dll.Load()
 	if err != nil {
+		log.Errorf("failed loading dll %v", err)
 		return nil, err
 	}
+
 	tunIface, err := tun.CreateTUN(c.name, c.mtu)
 	if err != nil {
 		return nil, err