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>

diff --git a/tun/wintun/dll_fromfile_windows.go b/tun/wintun/dll_fromfile_windows.go
new file mode 100644 (file)
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)
+}

diff --git a/tun/wintun/dll_fromrsrc_windows.go b/tun/wintun/dll_fromrsrc_windows.go
new file mode 100644 (file)
index 0000000..e6e393f
--- /dev/null
+++ b/tun/wintun/dll_fromrsrc_windows.go
@@ -0,0 +1,58 @@
+// +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)
+}

diff --git a/tun/wintun/dll_windows.go b/tun/wintun/dll_windows.go
index 4a55e979335f9b7103cc8f8cb1e795cf619616a7..9f04f73c2bc00aa4b1cf549c3285622b8e2eec62 100644 (file)
--- a/tun/wintun/dll_windows.go
+++ b/tun/wintun/dll_windows.go
@@ -10,50 +10,12 @@ import (
        "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 newLazyDLL(name string) *lazyDLL {
        return &lazyDLL{Name: name}
 }
 
-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 (d *lazyDLL) NewProc(name string) *lazyProc {
        return &lazyProc{dll: d, Name: name}
 }
@@ -79,7 +41,7 @@ func (p *lazyProc) Find() error {
        if err != nil {
                return fmt.Errorf("Error loading %v DLL: %w", p.dll.Name, err)
        }
-       addr, err := p.dll.module.ProcAddressByName(p.Name)
+       addr, err := p.nameToAddr()
        if err != nil {
                return fmt.Errorf("Error getting %v address: %w", p.Name, err)
        }