wintun: load wintun.dll from RCDATA resource

Signed-off-by: Simon Rozman <simon@rozman.si>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 143 insertions, 0 deletions

diff --git a/tun/wintun/resource/resource_windows.go b/tun/wintun/resource/resource_windows.go
new file mode 100644
index 0000000..109c2ca
--- /dev/null
+++ b/tun/wintun/resource/resource_windows.go
@@ -0,0 +1,143 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package resource
+
+import (
+	"errors"
+	"fmt"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+func MAKEINTRESOURCE(i uint16) *uint16 {
+	return (*uint16)(unsafe.Pointer(uintptr(i)))
+}
+
+// Predefined Resource Types
+var (
+	VS_VERSION_INFO uint16 = 1
+
+	RT_CURSOR                                          = MAKEINTRESOURCE(1)
+	RT_BITMAP                                          = MAKEINTRESOURCE(2)
+	RT_ICON                                            = MAKEINTRESOURCE(3)
+	RT_MENU                                            = MAKEINTRESOURCE(4)
+	RT_DIALOG                                          = MAKEINTRESOURCE(5)
+	RT_STRING                                          = MAKEINTRESOURCE(6)
+	RT_FONTDIR                                         = MAKEINTRESOURCE(7)
+	RT_FONT                                            = MAKEINTRESOURCE(8)
+	RT_ACCELERATOR                                     = MAKEINTRESOURCE(9)
+	RT_RCDATA                                          = MAKEINTRESOURCE(10)
+	RT_MESSAGETABLE                                    = MAKEINTRESOURCE(11)
+	RT_GROUP_CURSOR                                    = MAKEINTRESOURCE(12)
+	RT_GROUP_ICON                                      = MAKEINTRESOURCE(14)
+	RT_VERSION                                         = MAKEINTRESOURCE(16)
+	RT_DLGINCLUDE                                      = MAKEINTRESOURCE(17)
+	RT_PLUGPLAY                                        = MAKEINTRESOURCE(19)
+	RT_VXD                                             = MAKEINTRESOURCE(20)
+	RT_ANICURSOR                                       = MAKEINTRESOURCE(21)
+	RT_ANIICON                                         = MAKEINTRESOURCE(22)
+	RT_HTML                                            = MAKEINTRESOURCE(23)
+	RT_MANIFEST                                        = MAKEINTRESOURCE(24)
+	CREATEPROCESS_MANIFEST_RESOURCE_ID                 = MAKEINTRESOURCE(1)
+	ISOLATIONAWARE_MANIFEST_RESOURCE_ID                = MAKEINTRESOURCE(2)
+	ISOLATIONAWARE_NOSTATICIMPORT_MANIFEST_RESOURCE_ID = MAKEINTRESOURCE(3)
+	ISOLATIONPOLICY_MANIFEST_RESOURCE_ID               = MAKEINTRESOURCE(4)
+	ISOLATIONPOLICY_BROWSER_MANIFEST_RESOURCE_ID       = MAKEINTRESOURCE(5)
+	MINIMUM_RESERVED_MANIFEST_RESOURCE_ID              = MAKEINTRESOURCE(1 /*inclusive*/)
+	MAXIMUM_RESERVED_MANIFEST_RESOURCE_ID              = MAKEINTRESOURCE(16 /*inclusive*/)
+)
+
+//sys	findResource(module windows.Handle, name *uint16, resType *uint16) (resInfo windows.Handle, err error) = kernel32.FindResourceW
+
+func FindByID(module windows.Handle, id uint16, resType *uint16) (resInfo windows.Handle, err error) {
+	return findResource(module, MAKEINTRESOURCE(id), resType)
+}
+
+func FindByName(module windows.Handle, name string, resType *uint16) (resInfo windows.Handle, err error) {
+	var name16 *uint16
+	name16, err = windows.UTF16PtrFromString(name)
+	if err != nil {
+		return
+	}
+	resInfo, err = findResource(module, name16, resType)
+	return
+}
+
+//sys	sizeofResource(module windows.Handle, resInfo windows.Handle) (size uint32, err error) = kernel32.SizeofResource
+//sys	loadResource(module windows.Handle, resInfo windows.Handle) (resData windows.Handle, err error) = kernel32.LoadResource
+//sys	lockResource(resData windows.Handle) (addr uintptr, err error) = kernel32.LockResource
+
+func Load(module, resInfo windows.Handle) (data []byte, err error) {
+	size, err := sizeofResource(module, resInfo)
+	if err != nil {
+		err = fmt.Errorf("Unable to size resource: %v", err)
+		return
+	}
+	resData, err := loadResource(module, resInfo)
+	if err != nil {
+		err = fmt.Errorf("Unable to load resource: %v", err)
+		return
+	}
+	ptr, err := lockResource(resData)
+	if err != nil {
+		err = fmt.Errorf("Unable to lock resource: %v", err)
+		return
+	}
+	unsafeSlice(unsafe.Pointer(&data), unsafe.Pointer(ptr), int(size))
+	return
+}
+
+type VS_FIXEDFILEINFO struct {
+	Signature        uint32
+	StrucVersion     uint32
+	FileVersionMS    uint32
+	FileVersionLS    uint32
+	ProductVersionMS uint32
+	ProductVersionLS uint32
+	FileFlagsMask    uint32
+	FileFlags        uint32
+	FileOS           uint32
+	FileType         uint32
+	FileSubtype      uint32
+	FileDateMS       uint32
+	FileDateLS       uint32
+}
+
+//sys	verQueryValue(block *byte, section *uint16, value **byte, size *uint32) (err error) = version.VerQueryValueW
+
+func VerQueryRootValue(block []byte) (ffi *VS_FIXEDFILEINFO, err error) {
+	var data *byte
+	var size uint32
+	err = verQueryValue(&block[0], windows.StringToUTF16Ptr("\\"), &data, &size)
+	if err != nil {
+		return
+	}
+	if uintptr(size) < unsafe.Sizeof(VS_FIXEDFILEINFO{}) {
+		err = errors.New("Incomplete VS_FIXEDFILEINFO")
+		return
+	}
+	ffi = (*VS_FIXEDFILEINFO)(unsafe.Pointer(data))
+	return
+}
+
+// unsafeSlice updates the slice slicePtr to be a slice
+// referencing the provided data with its length & capacity set to
+// lenCap.
+//
+// TODO: when Go 1.16 or Go 1.17 is the minimum supported version,
+// update callers to use unsafe.Slice instead of this.
+func unsafeSlice(slicePtr, data unsafe.Pointer, lenCap int) {
+	type sliceHeader struct {
+		Data unsafe.Pointer
+		Len  int
+		Cap  int
+	}
+	h := (*sliceHeader)(slicePtr)
+	h.Data = data
+	h.Len = lenCap
+	h.Cap = lenCap
+}