wireguard-go/tun/wintun/dll_fromrsrc_windows.go
Jason A. Donenfeld 60b3766b89 wintun: load from filesystem by default
We let people loading this from resources opt in via:

    go build -tags load_wintun_from_rsrc

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-11-11 18:51:44 +01:00

59 lines
1.2 KiB
Go

// +build load_wintun_from_rsrc
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
*/
package wintun
import (
"fmt"
"sync"
"sync/atomic"
"unsafe"
"golang.org/x/sys/windows"
"golang.zx2c4.com/wireguard/tun/wintun/memmod"
"golang.zx2c4.com/wireguard/tun/wintun/resource"
)
type lazyDLL struct {
Name string
mu sync.Mutex
module *memmod.Module
}
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 := resource.FindByName(ourModule, d.Name, resource.RT_RCDATA)
if err != nil {
return fmt.Errorf("Unable to find \"%v\" RCDATA resource: %w", d.Name, err)
}
data, err := resource.Load(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)
}
atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&d.module)), unsafe.Pointer(module))
return nil
}
func (p *lazyProc) nameToAddr() (uintptr, error) {
return p.dll.module.ProcAddressByName(p.Name)
}