From 60b3766b89b9cc664d9bbdc9ab34b283e0374d21 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 11 Nov 2020 18:51:44 +0100 Subject: 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 --- tun/wintun/dll_fromfile_windows.go | 50 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 tun/wintun/dll_fromfile_windows.go (limited to 'tun/wintun/dll_fromfile_windows.go') diff --git a/tun/wintun/dll_fromfile_windows.go b/tun/wintun/dll_fromfile_windows.go new file mode 100644 index 0000000..525812b --- /dev/null +++ b/tun/wintun/dll_fromfile_windows.go @@ -0,0 +1,50 @@ +// +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" +) + +type lazyDLL struct { + Name string + mu sync.Mutex + module windows.Handle +} + +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 != 0 { + return nil + } + + const ( + LOAD_LIBRARY_SEARCH_APPLICATION_DIR = 0x00000200 + LOAD_LIBRARY_SEARCH_SYSTEM32 = 0x00000800 + ) + module, err := windows.LoadLibraryEx(d.Name, 0, LOAD_LIBRARY_SEARCH_APPLICATION_DIR|LOAD_LIBRARY_SEARCH_SYSTEM32) + 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 windows.GetProcAddress(p.dll.module, p.Name) +} -- cgit v1.2.3-59-g8ed1b