wireguard-go/tun/wintun/dll_fromrsrc_windows.go
Jason A. Donenfeld dfd688b6aa global: remove old-style build tags
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-10-12 12:02:10 -06:00

62 lines
1.3 KiB
Go

//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"
)
type lazyDLL struct {
Name string
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)
}
atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&d.module)), unsafe.Pointer(module))
if d.onLoad != nil {
d.onLoad(d)
}
return nil
}
func (p *lazyProc) nameToAddr() (uintptr, error) {
return p.dll.module.ProcAddressByName(p.Name)
}