wintun: load wintun.dll from RCDATA resource

Signed-off-by: Simon Rozman <simon@rozman.si> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2026-05-22 17:08:51 -07:00 · 2020-11-07 15:20:49 +01:00
parent 3e08b8aee0
commit 65e03a9182
19 changed files with 1578 additions and 2 deletions
@@ -5,6 +5,6 @@ go 1.13
 require (
 	golang.org/x/crypto v0.0.0-20200429183012-4b2356b1ed79
 	golang.org/x/net v0.0.0-20200501053045-e0ff5e5a1de5
-	golang.org/x/sys v0.0.0-20201027130517-9d1ec526b7bf
+	golang.org/x/sys v0.0.0-20201107080550-4d91cf3a1aaf
 	golang.org/x/text v0.3.2
 )
@@ -9,6 +9,8 @@ golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201027130517-9d1ec526b7bf h1:HmHgHRpqpvB74D7bjXkue6kkHJfOrKyYJtW6Sv4jpI4=
 golang.org/x/sys v0.0.0-20201027130517-9d1ec526b7bf/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201107080550-4d91cf3a1aaf h1:kt3wY1Lu5MJAnKTfoMR52Cu4gwvna4VTzNOiT8tY73s=
+golang.org/x/sys v0.0.0-20201107080550-4d91cf3a1aaf/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 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 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: %v", d.Name, err)
+	}
+	data, err := resource.Load(ourModule, resInfo)
+	if err != nil {
+		return fmt.Errorf("Unable to load resource: %v", err)
+	}
+	module, err := memmod.LoadLibrary(data)
+	if err != nil {
+		return fmt.Errorf("Unable to load library: %v", 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}
+}
+
+type lazyProc struct {
+	Name string
+	mu   sync.Mutex
+	dll  *lazyDLL
+	addr uintptr
+}
+
+func (p *lazyProc) Find() error {
+	if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&p.addr))) != nil {
+		return nil
+	}
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if p.addr != 0 {
+		return nil
+	}
+
+	err := p.dll.Load()
+	if err != nil {
+		return fmt.Errorf("Error loading %v DLL: %v", p.dll.Name, err)
+	}
+	addr, err := p.dll.module.ProcAddressByName(p.Name)
+	if err != nil {
+		return fmt.Errorf("Error getting %v address: %v", p.Name, err)
+	}
+
+	atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&p.addr)), unsafe.Pointer(addr))
+	return nil
+}
+
+func (p *lazyProc) Addr() uintptr {
+	err := p.Find()
+	if err != nil {
+		panic(err)
+	}
+	return p.addr
+}
@@ -0,0 +1,16 @@
+// +build 386 arm
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+func (opthdr *IMAGE_OPTIONAL_HEADER) imageOffset() uintptr {
+	return 0
+}
+
+func (module *Module) check4GBBoundaries(alignedImageSize uintptr) (err error) {
+	return
+}
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_I386
@@ -0,0 +1,36 @@
+// +build amd64 arm64
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+import (
+	"fmt"
+
+	"golang.org/x/sys/windows"
+)
+
+func (opthdr *IMAGE_OPTIONAL_HEADER) imageOffset() uintptr {
+	return uintptr(opthdr.ImageBase & 0xffffffff00000000)
+}
+
+func (module *Module) check4GBBoundaries(alignedImageSize uintptr) (err error) {
+	for (module.codeBase >> 32) < ((module.codeBase + alignedImageSize) >> 32) {
+		node := &addressList{
+			next:    module.blockedMemory,
+			address: module.codeBase,
+		}
+		module.blockedMemory = node
+		module.codeBase, err = windows.VirtualAlloc(0,
+			alignedImageSize,
+			windows.MEM_RESERVE|windows.MEM_COMMIT,
+			windows.PAGE_READWRITE)
+		if err != nil {
+			return fmt.Errorf("Error allocating memory block: %v", err)
+		}
+	}
+	return
+}
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_AMD64
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_ARMNT
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+const imageFileProcess = IMAGE_FILE_MACHINE_ARM64
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go syscall_windows.go
@@ -0,0 +1,343 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+import "unsafe"
+
+const (
+	IMAGE_DOS_SIGNATURE    = 0x5A4D     // MZ
+	IMAGE_OS2_SIGNATURE    = 0x454E     // NE
+	IMAGE_OS2_SIGNATURE_LE = 0x454C     // LE
+	IMAGE_VXD_SIGNATURE    = 0x454C     // LE
+	IMAGE_NT_SIGNATURE     = 0x00004550 // PE00
+)
+
+// DOS .EXE header
+type IMAGE_DOS_HEADER struct {
+	E_magic    uint16     // Magic number
+	E_cblp     uint16     // Bytes on last page of file
+	E_cp       uint16     // Pages in file
+	E_crlc     uint16     // Relocations
+	E_cparhdr  uint16     // Size of header in paragraphs
+	E_minalloc uint16     // Minimum extra paragraphs needed
+	E_maxalloc uint16     // Maximum extra paragraphs needed
+	E_ss       uint16     // Initial (relative) SS value
+	E_sp       uint16     // Initial SP value
+	E_csum     uint16     // Checksum
+	E_ip       uint16     // Initial IP value
+	E_cs       uint16     // Initial (relative) CS value
+	E_lfarlc   uint16     // File address of relocation table
+	E_ovno     uint16     // Overlay number
+	E_res      [4]uint16  // Reserved words
+	E_oemid    uint16     // OEM identifier (for e_oeminfo)
+	E_oeminfo  uint16     // OEM information; e_oemid specific
+	E_res2     [10]uint16 // Reserved words
+	E_lfanew   int32      // File address of new exe header
+}
+
+// File header format
+type IMAGE_FILE_HEADER struct {
+	Machine              uint16
+	NumberOfSections     uint16
+	TimeDateStamp        uint32
+	PointerToSymbolTable uint32
+	NumberOfSymbols      uint32
+	SizeOfOptionalHeader uint16
+	Characteristics      uint16
+}
+
+const (
+	IMAGE_SIZEOF_FILE_HEADER = 20
+
+	IMAGE_FILE_RELOCS_STRIPPED         = 0x0001 // Relocation info stripped from file.
+	IMAGE_FILE_EXECUTABLE_IMAGE        = 0x0002 // File is executable  (i.e. no unresolved external references).
+	IMAGE_FILE_LINE_NUMS_STRIPPED      = 0x0004 // Line nunbers stripped from file.
+	IMAGE_FILE_LOCAL_SYMS_STRIPPED     = 0x0008 // Local symbols stripped from file.
+	IMAGE_FILE_AGGRESIVE_WS_TRIM       = 0x0010 // Aggressively trim working set
+	IMAGE_FILE_LARGE_ADDRESS_AWARE     = 0x0020 // App can handle >2gb addresses
+	IMAGE_FILE_BYTES_REVERSED_LO       = 0x0080 // Bytes of machine word are reversed.
+	IMAGE_FILE_32BIT_MACHINE           = 0x0100 // 32 bit word machine.
+	IMAGE_FILE_DEBUG_STRIPPED          = 0x0200 // Debugging info stripped from file in .DBG file
+	IMAGE_FILE_REMOVABLE_RUN_FROM_SWAP = 0x0400 // If Image is on removable media, copy and run from the swap file.
+	IMAGE_FILE_NET_RUN_FROM_SWAP       = 0x0800 // If Image is on Net, copy and run from the swap file.
+	IMAGE_FILE_SYSTEM                  = 0x1000 // System File.
+	IMAGE_FILE_DLL                     = 0x2000 // File is a DLL.
+	IMAGE_FILE_UP_SYSTEM_ONLY          = 0x4000 // File should only be run on a UP machine
+	IMAGE_FILE_BYTES_REVERSED_HI       = 0x8000 // Bytes of machine word are reversed.
+
+	IMAGE_FILE_MACHINE_UNKNOWN     = 0
+	IMAGE_FILE_MACHINE_TARGET_HOST = 0x0001 // Useful for indicating we want to interact with the host and not a WoW guest.
+	IMAGE_FILE_MACHINE_I386        = 0x014c // Intel 386.
+	IMAGE_FILE_MACHINE_R3000       = 0x0162 // MIPS little-endian, 0x160 big-endian
+	IMAGE_FILE_MACHINE_R4000       = 0x0166 // MIPS little-endian
+	IMAGE_FILE_MACHINE_R10000      = 0x0168 // MIPS little-endian
+	IMAGE_FILE_MACHINE_WCEMIPSV2   = 0x0169 // MIPS little-endian WCE v2
+	IMAGE_FILE_MACHINE_ALPHA       = 0x0184 // Alpha_AXP
+	IMAGE_FILE_MACHINE_SH3         = 0x01a2 // SH3 little-endian
+	IMAGE_FILE_MACHINE_SH3DSP      = 0x01a3
+	IMAGE_FILE_MACHINE_SH3E        = 0x01a4 // SH3E little-endian
+	IMAGE_FILE_MACHINE_SH4         = 0x01a6 // SH4 little-endian
+	IMAGE_FILE_MACHINE_SH5         = 0x01a8 // SH5
+	IMAGE_FILE_MACHINE_ARM         = 0x01c0 // ARM Little-Endian
+	IMAGE_FILE_MACHINE_THUMB       = 0x01c2 // ARM Thumb/Thumb-2 Little-Endian
+	IMAGE_FILE_MACHINE_ARMNT       = 0x01c4 // ARM Thumb-2 Little-Endian
+	IMAGE_FILE_MACHINE_AM33        = 0x01d3
+	IMAGE_FILE_MACHINE_POWERPC     = 0x01F0 // IBM PowerPC Little-Endian
+	IMAGE_FILE_MACHINE_POWERPCFP   = 0x01f1
+	IMAGE_FILE_MACHINE_IA64        = 0x0200 // Intel 64
+	IMAGE_FILE_MACHINE_MIPS16      = 0x0266 // MIPS
+	IMAGE_FILE_MACHINE_ALPHA64     = 0x0284 // ALPHA64
+	IMAGE_FILE_MACHINE_MIPSFPU     = 0x0366 // MIPS
+	IMAGE_FILE_MACHINE_MIPSFPU16   = 0x0466 // MIPS
+	IMAGE_FILE_MACHINE_AXP64       = IMAGE_FILE_MACHINE_ALPHA64
+	IMAGE_FILE_MACHINE_TRICORE     = 0x0520 // Infineon
+	IMAGE_FILE_MACHINE_CEF         = 0x0CEF
+	IMAGE_FILE_MACHINE_EBC         = 0x0EBC // EFI Byte Code
+	IMAGE_FILE_MACHINE_AMD64       = 0x8664 // AMD64 (K8)
+	IMAGE_FILE_MACHINE_M32R        = 0x9041 // M32R little-endian
+	IMAGE_FILE_MACHINE_ARM64       = 0xAA64 // ARM64 Little-Endian
+	IMAGE_FILE_MACHINE_CEE         = 0xC0EE
+)
+
+// Directory format
+type IMAGE_DATA_DIRECTORY struct {
+	VirtualAddress uint32
+	Size           uint32
+}
+
+const IMAGE_NUMBEROF_DIRECTORY_ENTRIES = 16
+
+type IMAGE_NT_HEADERS struct {
+	Signature      uint32
+	FileHeader     IMAGE_FILE_HEADER
+	OptionalHeader IMAGE_OPTIONAL_HEADER
+}
+
+func (ntheader *IMAGE_NT_HEADERS) Sections() []IMAGE_SECTION_HEADER {
+	return (*[0xffff]IMAGE_SECTION_HEADER)(unsafe.Pointer(
+		(uintptr)(unsafe.Pointer(ntheader)) +
+			unsafe.Offsetof(ntheader.OptionalHeader) +
+			uintptr(ntheader.FileHeader.SizeOfOptionalHeader)))[:ntheader.FileHeader.NumberOfSections]
+}
+
+const (
+	IMAGE_DIRECTORY_ENTRY_EXPORT         = 0  // Export Directory
+	IMAGE_DIRECTORY_ENTRY_IMPORT         = 1  // Import Directory
+	IMAGE_DIRECTORY_ENTRY_RESOURCE       = 2  // Resource Directory
+	IMAGE_DIRECTORY_ENTRY_EXCEPTION      = 3  // Exception Directory
+	IMAGE_DIRECTORY_ENTRY_SECURITY       = 4  // Security Directory
+	IMAGE_DIRECTORY_ENTRY_BASERELOC      = 5  // Base Relocation Table
+	IMAGE_DIRECTORY_ENTRY_DEBUG          = 6  // Debug Directory
+	IMAGE_DIRECTORY_ENTRY_COPYRIGHT      = 7  // (X86 usage)
+	IMAGE_DIRECTORY_ENTRY_ARCHITECTURE   = 7  // Architecture Specific Data
+	IMAGE_DIRECTORY_ENTRY_GLOBALPTR      = 8  // RVA of GP
+	IMAGE_DIRECTORY_ENTRY_TLS            = 9  // TLS Directory
+	IMAGE_DIRECTORY_ENTRY_LOAD_CONFIG    = 10 // Load Configuration Directory
+	IMAGE_DIRECTORY_ENTRY_BOUND_IMPORT   = 11 // Bound Import Directory in headers
+	IMAGE_DIRECTORY_ENTRY_IAT            = 12 // Import Address Table
+	IMAGE_DIRECTORY_ENTRY_DELAY_IMPORT   = 13 // Delay Load Import Descriptors
+	IMAGE_DIRECTORY_ENTRY_COM_DESCRIPTOR = 14 // COM Runtime descriptor
+)
+
+const IMAGE_SIZEOF_SHORT_NAME = 8
+
+// Section header format
+type IMAGE_SECTION_HEADER struct {
+	Name                         [IMAGE_SIZEOF_SHORT_NAME]byte
+	physicalAddressOrVirtualSize uint32
+	VirtualAddress               uint32
+	SizeOfRawData                uint32
+	PointerToRawData             uint32
+	PointerToRelocations         uint32
+	PointerToLinenumbers         uint32
+	NumberOfRelocations          uint16
+	NumberOfLinenumbers          uint16
+	Characteristics              uint32
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) PhysicalAddress() uint32 {
+	return ishdr.physicalAddressOrVirtualSize
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) SetPhysicalAddress(addr uint32) {
+	ishdr.physicalAddressOrVirtualSize = addr
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) VirtualSize() uint32 {
+	return ishdr.physicalAddressOrVirtualSize
+}
+
+func (ishdr *IMAGE_SECTION_HEADER) SetVirtualSize(addr uint32) {
+	ishdr.physicalAddressOrVirtualSize = addr
+}
+
+const (
+	// Section characteristics.
+	IMAGE_SCN_TYPE_REG    = 0x00000000 // Reserved.
+	IMAGE_SCN_TYPE_DSECT  = 0x00000001 // Reserved.
+	IMAGE_SCN_TYPE_NOLOAD = 0x00000002 // Reserved.
+	IMAGE_SCN_TYPE_GROUP  = 0x00000004 // Reserved.
+	IMAGE_SCN_TYPE_NO_PAD = 0x00000008 // Reserved.
+	IMAGE_SCN_TYPE_COPY   = 0x00000010 // Reserved.
+
+	IMAGE_SCN_CNT_CODE               = 0x00000020 // Section contains code.
+	IMAGE_SCN_CNT_INITIALIZED_DATA   = 0x00000040 // Section contains initialized data.
+	IMAGE_SCN_CNT_UNINITIALIZED_DATA = 0x00000080 // Section contains uninitialized data.
+
+	IMAGE_SCN_LNK_OTHER         = 0x00000100 // Reserved.
+	IMAGE_SCN_LNK_INFO          = 0x00000200 // Section contains comments or some other type of information.
+	IMAGE_SCN_TYPE_OVER         = 0x00000400 // Reserved.
+	IMAGE_SCN_LNK_REMOVE        = 0x00000800 // Section contents will not become part of image.
+	IMAGE_SCN_LNK_COMDAT        = 0x00001000 // Section contents comdat.
+	IMAGE_SCN_MEM_PROTECTED     = 0x00004000 // Obsolete.
+	IMAGE_SCN_NO_DEFER_SPEC_EXC = 0x00004000 // Reset speculative exceptions handling bits in the TLB entries for this section.
+	IMAGE_SCN_GPREL             = 0x00008000 // Section content can be accessed relative to GP
+	IMAGE_SCN_MEM_FARDATA       = 0x00008000
+	IMAGE_SCN_MEM_SYSHEAP       = 0x00010000 // Obsolete.
+	IMAGE_SCN_MEM_PURGEABLE     = 0x00020000
+	IMAGE_SCN_MEM_16BIT         = 0x00020000
+	IMAGE_SCN_MEM_LOCKED        = 0x00040000
+	IMAGE_SCN_MEM_PRELOAD       = 0x00080000
+
+	IMAGE_SCN_ALIGN_1BYTES    = 0x00100000 //
+	IMAGE_SCN_ALIGN_2BYTES    = 0x00200000 //
+	IMAGE_SCN_ALIGN_4BYTES    = 0x00300000 //
+	IMAGE_SCN_ALIGN_8BYTES    = 0x00400000 //
+	IMAGE_SCN_ALIGN_16BYTES   = 0x00500000 // Default alignment if no others are specified.
+	IMAGE_SCN_ALIGN_32BYTES   = 0x00600000 //
+	IMAGE_SCN_ALIGN_64BYTES   = 0x00700000 //
+	IMAGE_SCN_ALIGN_128BYTES  = 0x00800000 //
+	IMAGE_SCN_ALIGN_256BYTES  = 0x00900000 //
+	IMAGE_SCN_ALIGN_512BYTES  = 0x00A00000 //
+	IMAGE_SCN_ALIGN_1024BYTES = 0x00B00000 //
+	IMAGE_SCN_ALIGN_2048BYTES = 0x00C00000 //
+	IMAGE_SCN_ALIGN_4096BYTES = 0x00D00000 //
+	IMAGE_SCN_ALIGN_8192BYTES = 0x00E00000 //
+	IMAGE_SCN_ALIGN_MASK      = 0x00F00000
+
+	IMAGE_SCN_LNK_NRELOC_OVFL = 0x01000000 // Section contains extended relocations.
+	IMAGE_SCN_MEM_DISCARDABLE = 0x02000000 // Section can be discarded.
+	IMAGE_SCN_MEM_NOT_CACHED  = 0x04000000 // Section is not cachable.
+	IMAGE_SCN_MEM_NOT_PAGED   = 0x08000000 // Section is not pageable.
+	IMAGE_SCN_MEM_SHARED      = 0x10000000 // Section is shareable.
+	IMAGE_SCN_MEM_EXECUTE     = 0x20000000 // Section is executable.
+	IMAGE_SCN_MEM_READ        = 0x40000000 // Section is readable.
+	IMAGE_SCN_MEM_WRITE       = 0x80000000 // Section is writeable.
+
+	// TLS Characteristic Flags
+	IMAGE_SCN_SCALE_INDEX = 0x00000001 // Tls index is scaled.
+)
+
+// Based relocation format
+type IMAGE_BASE_RELOCATION struct {
+	VirtualAddress uint32
+	SizeOfBlock    uint32
+}
+
+const (
+	IMAGE_REL_BASED_ABSOLUTE           = 0
+	IMAGE_REL_BASED_HIGH               = 1
+	IMAGE_REL_BASED_LOW                = 2
+	IMAGE_REL_BASED_HIGHLOW            = 3
+	IMAGE_REL_BASED_HIGHADJ            = 4
+	IMAGE_REL_BASED_MACHINE_SPECIFIC_5 = 5
+	IMAGE_REL_BASED_RESERVED           = 6
+	IMAGE_REL_BASED_MACHINE_SPECIFIC_7 = 7
+	IMAGE_REL_BASED_MACHINE_SPECIFIC_8 = 8
+	IMAGE_REL_BASED_MACHINE_SPECIFIC_9 = 9
+	IMAGE_REL_BASED_DIR64              = 10
+
+	IMAGE_REL_BASED_IA64_IMM64 = 9
+
+	IMAGE_REL_BASED_MIPS_JMPADDR   = 5
+	IMAGE_REL_BASED_MIPS_JMPADDR16 = 9
+
+	IMAGE_REL_BASED_ARM_MOV32   = 5
+	IMAGE_REL_BASED_THUMB_MOV32 = 7
+)
+
+// Export Format
+type IMAGE_EXPORT_DIRECTORY struct {
+	Characteristics       uint32
+	TimeDateStamp         uint32
+	MajorVersion          uint16
+	MinorVersion          uint16
+	Name                  uint32
+	Base                  uint32
+	NumberOfFunctions     uint32
+	NumberOfNames         uint32
+	AddressOfFunctions    uint32 // RVA from base of image
+	AddressOfNames        uint32 // RVA from base of image
+	AddressOfNameOrdinals uint32 // RVA from base of image
+}
+
+type IMAGE_IMPORT_BY_NAME struct {
+	Hint uint16
+	Name [1]byte
+}
+
+func IMAGE_ORDINAL(ordinal uintptr) uintptr {
+	return ordinal & 0xffff
+}
+
+func IMAGE_SNAP_BY_ORDINAL(ordinal uintptr) bool {
+	return (ordinal & IMAGE_ORDINAL_FLAG) != 0
+}
+
+// Thread Local Storage
+type IMAGE_TLS_DIRECTORY struct {
+	StartAddressOfRawData uintptr
+	EndAddressOfRawData   uintptr
+	AddressOfIndex        uintptr // PDWORD
+	AddressOfCallbacks    uintptr // PIMAGE_TLS_CALLBACK *;
+	SizeOfZeroFill        uint32
+	Characteristics       uint32
+}
+
+type IMAGE_IMPORT_DESCRIPTOR struct {
+	characteristicsOrOriginalFirstThunk uint32 // 0 for terminating null import descriptor
+	// RVA to original unbound IAT (PIMAGE_THUNK_DATA)
+	TimeDateStamp uint32 // 0 if not bound,
+	// -1 if bound, and real date\time stamp
+	//     in IMAGE_DIRECTORY_ENTRY_BOUND_IMPORT (new BIND)
+	// O.W. date/time stamp of DLL bound to (Old BIND)
+	ForwarderChain uint32 // -1 if no forwarders
+	Name           uint32
+	FirstThunk     uint32 // RVA to IAT (if bound this IAT has actual addresses)
+}
+
+func (imgimpdesc *IMAGE_IMPORT_DESCRIPTOR) Characteristics() uint32 {
+	return imgimpdesc.characteristicsOrOriginalFirstThunk
+}
+
+func (imgimpdesc *IMAGE_IMPORT_DESCRIPTOR) OriginalFirstThunk() uint32 {
+	return imgimpdesc.characteristicsOrOriginalFirstThunk
+}
+
+const (
+	DLL_PROCESS_ATTACH = 1
+	DLL_THREAD_ATTACH  = 2
+	DLL_THREAD_DETACH  = 3
+	DLL_PROCESS_DETACH = 0
+)
+
+//sys	loadLibraryA(libFileName *byte) (module windows.Handle, err error) = kernel32.LoadLibraryA
+//sys	getProcAddress(module windows.Handle, procName *byte) (addr uintptr, err error) = kernel32.GetProcAddress
+//sys	isBadReadPtr(addr uintptr, ucb uintptr) (ret bool) = kernel32.IsBadReadPtr
+
+type SYSTEM_INFO struct {
+	ProcessorArchitecture     uint16
+	Reserved                  uint16
+	PageSize                  uint32
+	MinimumApplicationAddress uintptr
+	MaximumApplicationAddress uintptr
+	ActiveProcessorMask       uintptr
+	NumberOfProcessors        uint32
+	ProcessorType             uint32
+	AllocationGranularity     uint32
+	ProcessorLevel            uint16
+	ProcessorRevision         uint16
+}
@@ -0,0 +1,45 @@
+// +build 386 arm
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+// Optional header format
+type IMAGE_OPTIONAL_HEADER struct {
+	Magic                       uint16
+	MajorLinkerVersion          uint8
+	MinorLinkerVersion          uint8
+	SizeOfCode                  uint32
+	SizeOfInitializedData       uint32
+	SizeOfUninitializedData     uint32
+	AddressOfEntryPoint         uint32
+	BaseOfCode                  uint32
+	BaseOfData                  uint32
+	ImageBase                   uintptr
+	SectionAlignment            uint32
+	FileAlignment               uint32
+	MajorOperatingSystemVersion uint16
+	MinorOperatingSystemVersion uint16
+	MajorImageVersion           uint16
+	MinorImageVersion           uint16
+	MajorSubsystemVersion       uint16
+	MinorSubsystemVersion       uint16
+	Win32VersionValue           uint32
+	SizeOfImage                 uint32
+	SizeOfHeaders               uint32
+	CheckSum                    uint32
+	Subsystem                   uint16
+	DllCharacteristics          uint16
+	SizeOfStackReserve          uintptr
+	SizeOfStackCommit           uintptr
+	SizeOfHeapReserve           uintptr
+	SizeOfHeapCommit            uintptr
+	LoaderFlags                 uint32
+	NumberOfRvaAndSizes         uint32
+	DataDirectory               [IMAGE_NUMBEROF_DIRECTORY_ENTRIES]IMAGE_DATA_DIRECTORY
+}
+
+const IMAGE_ORDINAL_FLAG uintptr = 0x80000000
@@ -0,0 +1,44 @@
+// +build amd64 arm64
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package memmod
+
+// Optional header format
+type IMAGE_OPTIONAL_HEADER struct {
+	Magic                       uint16
+	MajorLinkerVersion          uint8
+	MinorLinkerVersion          uint8
+	SizeOfCode                  uint32
+	SizeOfInitializedData       uint32
+	SizeOfUninitializedData     uint32
+	AddressOfEntryPoint         uint32
+	BaseOfCode                  uint32
+	ImageBase                   uintptr
+	SectionAlignment            uint32
+	FileAlignment               uint32
+	MajorOperatingSystemVersion uint16
+	MinorOperatingSystemVersion uint16
+	MajorImageVersion           uint16
+	MinorImageVersion           uint16
+	MajorSubsystemVersion       uint16
+	MinorSubsystemVersion       uint16
+	Win32VersionValue           uint32
+	SizeOfImage                 uint32
+	SizeOfHeaders               uint32
+	CheckSum                    uint32
+	Subsystem                   uint16
+	DllCharacteristics          uint16
+	SizeOfStackReserve          uintptr
+	SizeOfStackCommit           uintptr
+	SizeOfHeapReserve           uintptr
+	SizeOfHeapCommit            uintptr
+	LoaderFlags                 uint32
+	NumberOfRvaAndSizes         uint32
+	DataDirectory               [IMAGE_NUMBEROF_DIRECTORY_ENTRIES]IMAGE_DATA_DIRECTORY
+}
+
+const IMAGE_ORDINAL_FLAG uintptr = 0x8000000000000000
@@ -0,0 +1,70 @@
+// Code generated by 'go generate'; DO NOT EDIT.
+
+package memmod
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+	errnoERROR_IO_PENDING = 997
+)
+
+var (
+	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+	errERROR_EINVAL     error = syscall.EINVAL
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+	switch e {
+	case 0:
+		return errERROR_EINVAL
+	case errnoERROR_IO_PENDING:
+		return errERROR_IO_PENDING
+	}
+	// TODO: add more here, after collecting data on the common
+	// error values see on Windows. (perhaps when running
+	// all.bat?)
+	return e
+}
+
+var (
+	modkernel32 = windows.NewLazySystemDLL("kernel32.dll")
+
+	procGetProcAddress = modkernel32.NewProc("GetProcAddress")
+	procIsBadReadPtr   = modkernel32.NewProc("IsBadReadPtr")
+	procLoadLibraryA   = modkernel32.NewProc("LoadLibraryA")
+)
+
+func getProcAddress(module windows.Handle, procName *byte) (addr uintptr, err error) {
+	r0, _, e1 := syscall.Syscall(procGetProcAddress.Addr(), 2, uintptr(module), uintptr(unsafe.Pointer(procName)), 0)
+	addr = uintptr(r0)
+	if addr == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func isBadReadPtr(addr uintptr, ucb uintptr) (ret bool) {
+	r0, _, _ := syscall.Syscall(procIsBadReadPtr.Addr(), 2, uintptr(addr), uintptr(ucb), 0)
+	ret = r0 != 0
+	return
+}
+
+func loadLibraryA(libFileName *byte) (module windows.Handle, err error) {
+	r0, _, e1 := syscall.Syscall(procLoadLibraryA.Addr(), 1, uintptr(unsafe.Pointer(libFileName)), 0, 0)
+	module = windows.Handle(r0)
+	if module == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package resource
+
+//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go 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
+}
@@ -0,0 +1,112 @@
+// Code generated by 'go generate'; DO NOT EDIT.
+
+package resource
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+	errnoERROR_IO_PENDING = 997
+)
+
+var (
+	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+	switch e {
+	case 0:
+		return nil
+	case errnoERROR_IO_PENDING:
+		return errERROR_IO_PENDING
+	}
+	// TODO: add more here, after collecting data on the common
+	// error values see on Windows. (perhaps when running
+	// all.bat?)
+	return e
+}
+
+var (
+	modkernel32 = windows.NewLazySystemDLL("kernel32.dll")
+	modversion  = windows.NewLazySystemDLL("version.dll")
+
+	procFindResourceW  = modkernel32.NewProc("FindResourceW")
+	procSizeofResource = modkernel32.NewProc("SizeofResource")
+	procLoadResource   = modkernel32.NewProc("LoadResource")
+	procLockResource   = modkernel32.NewProc("LockResource")
+	procVerQueryValueW = modversion.NewProc("VerQueryValueW")
+)
+
+func findResource(module windows.Handle, name *uint16, resType *uint16) (resInfo windows.Handle, err error) {
+	r0, _, e1 := syscall.Syscall(procFindResourceW.Addr(), 3, uintptr(module), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(resType)))
+	resInfo = windows.Handle(r0)
+	if resInfo == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func sizeofResource(module windows.Handle, resInfo windows.Handle) (size uint32, err error) {
+	r0, _, e1 := syscall.Syscall(procSizeofResource.Addr(), 2, uintptr(module), uintptr(resInfo), 0)
+	size = uint32(r0)
+	if size == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func loadResource(module windows.Handle, resInfo windows.Handle) (resData windows.Handle, err error) {
+	r0, _, e1 := syscall.Syscall(procLoadResource.Addr(), 2, uintptr(module), uintptr(resInfo), 0)
+	resData = windows.Handle(r0)
+	if resData == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func lockResource(resData windows.Handle) (addr uintptr, err error) {
+	r0, _, e1 := syscall.Syscall(procLockResource.Addr(), 1, uintptr(resData), 0, 0)
+	addr = uintptr(r0)
+	if addr == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func verQueryValue(block *byte, section *uint16, value **byte, size *uint32) (err error) {
+	r1, _, e1 := syscall.Syscall6(procVerQueryValueW.Addr(), 4, uintptr(unsafe.Pointer(block)), uintptr(unsafe.Pointer(section)), uintptr(unsafe.Pointer(value)), uintptr(unsafe.Pointer(size)), 0, 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
@@ -34,7 +34,7 @@ type Adapter struct {
 }

 var (
-	modwintun = windows.NewLazyDLL("wintun.dll")
+	modwintun = newLazyDLL("wintun.dll")

 	procWintunCreateAdapter           = modwintun.NewProc("WintunCreateAdapter")
 	procWintunDeleteAdapter           = modwintun.NewProc("WintunDeleteAdapter")