syscall_windows.mx raw

   1  // Copyright 2009 The Go Authors. All rights reserved.
   2  // Use of this source code is governed by a BSD-style
   3  // license that can be found in the LICENSE file.
   4  
   5  // Windows system calls.
   6  
   7  package syscall
   8  
   9  import (
  10  	errorspkg "errors"
  11  	"internal/asan"
  12  	"internal/bytealg"
  13  	"internal/itoa"
  14  	"internal/msan"
  15  	"internal/oserror"
  16  	"internal/race"
  17  	"runtime"
  18  	"sync"
  19  	"unsafe"
  20  )
  21  
  22  type Handle uintptr
  23  
  24  const InvalidHandle = ^Handle(0)
  25  
  26  // StringToUTF16 returns the UTF-16 encoding of the UTF-8 string s,
  27  // with a terminating NUL added. If s contains a NUL byte this
  28  // function panics instead of returning an error.
  29  //
  30  // Deprecated: Use [UTF16FromString] instead.
  31  func StringToUTF16(s string) []uint16 {
  32  	a, err := UTF16FromString(s)
  33  	if err != nil {
  34  		panic("syscall: string with NUL passed to StringToUTF16")
  35  	}
  36  	return a
  37  }
  38  
  39  // UTF16FromString returns the UTF-16 encoding of the UTF-8 string
  40  // s, with a terminating NUL added. If s contains a NUL byte at any
  41  // location, it returns (nil, [EINVAL]). Unpaired surrogates
  42  // are encoded using WTF-8.
  43  func UTF16FromString(s string) ([]uint16, error) {
  44  	if bytealg.IndexByteString(s, 0) != -1 {
  45  		return nil, EINVAL
  46  	}
  47  	// Valid UTF-8 characters between 1 and 3 bytes require one uint16.
  48  	// Valid UTF-8 characters of 4 bytes require two uint16.
  49  	// Bytes with invalid UTF-8 encoding require maximum one uint16 per byte.
  50  	// So the number of UTF-8 code units (len(s)) is always greater or
  51  	// equal than the number of UTF-16 code units.
  52  	// Also account for the terminating NUL character.
  53  	buf := make([]uint16, 0, len(s)+1)
  54  	buf = encodeWTF16(s, buf)
  55  	return append(buf, 0), nil
  56  }
  57  
  58  // UTF16ToString returns the UTF-8 encoding of the UTF-16 sequence s,
  59  // with a terminating NUL removed. Unpaired surrogates are decoded
  60  // using WTF-8 instead of UTF-8 encoding.
  61  func UTF16ToString(s []uint16) string {
  62  	maxLen := 0
  63  	for i, v := range s {
  64  		if v == 0 {
  65  			s = s[0:i]
  66  			break
  67  		}
  68  		switch {
  69  		case v <= rune1Max:
  70  			maxLen += 1
  71  		case v <= rune2Max:
  72  			maxLen += 2
  73  		default:
  74  			// r is a non-surrogate that decodes to 3 bytes,
  75  			// or is an unpaired surrogate (also 3 bytes in WTF-8),
  76  			// or is one half of a valid surrogate pair.
  77  			// If it is half of a pair, we will add 3 for the second surrogate
  78  			// (total of 6) and overestimate by 2 bytes for the pair,
  79  			// since the resulting rune only requires 4 bytes.
  80  			maxLen += 3
  81  		}
  82  	}
  83  	buf := decodeWTF16(s, make([]byte, 0, maxLen))
  84  	return unsafe.String(unsafe.SliceData(buf), len(buf))
  85  }
  86  
  87  // utf16PtrToString is like UTF16ToString, but takes *uint16
  88  // as a parameter instead of []uint16.
  89  func utf16PtrToString(p *uint16) string {
  90  	if p == nil {
  91  		return ""
  92  	}
  93  	end := unsafe.Pointer(p)
  94  	n := 0
  95  	for *(*uint16)(end) != 0 {
  96  		end = unsafe.Pointer(uintptr(end) + unsafe.Sizeof(*p))
  97  		n++
  98  	}
  99  	return UTF16ToString(unsafe.Slice(p, n))
 100  }
 101  
 102  // StringToUTF16Ptr returns pointer to the UTF-16 encoding of
 103  // the UTF-8 string s, with a terminating NUL added. If s
 104  // contains a NUL byte this function panics instead of
 105  // returning an error.
 106  //
 107  // Deprecated: Use [UTF16PtrFromString] instead.
 108  func StringToUTF16Ptr(s string) *uint16 { return &StringToUTF16(s)[0] }
 109  
 110  // UTF16PtrFromString returns pointer to the UTF-16 encoding of
 111  // the UTF-8 string s, with a terminating NUL added. If s
 112  // contains a NUL byte at any location, it returns (nil, EINVAL).
 113  // Unpaired surrogates are encoded using WTF-8.
 114  func UTF16PtrFromString(s string) (*uint16, error) {
 115  	a, err := UTF16FromString(s)
 116  	if err != nil {
 117  		return nil, err
 118  	}
 119  	return &a[0], nil
 120  }
 121  
 122  // Errno is the Windows error number.
 123  //
 124  // Errno values can be tested against error values using [errors.Is].
 125  // For example:
 126  //
 127  //	_, _, err := syscall.Syscall(...)
 128  //	if errors.Is(err, fs.ErrNotExist) ...
 129  type Errno uintptr
 130  
 131  func langid(pri, sub uint16) uint32 { return uint32(sub)<<10 | uint32(pri) }
 132  
 133  // FormatMessage is deprecated (msgsrc should be uintptr, not uint32, but can
 134  // not be changed due to the Go 1 compatibility guarantee).
 135  //
 136  // Deprecated: Use FormatMessage from golang.org/x/sys/windows instead.
 137  func FormatMessage(flags uint32, msgsrc uint32, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) {
 138  	return formatMessage(flags, uintptr(msgsrc), msgid, langid, buf, args)
 139  }
 140  
 141  var errnoErrorCache sync.Map
 142  
 143  func (e Errno) Error() string {
 144  	// deal with special go errors
 145  	idx := int(e - APPLICATION_ERROR)
 146  	if 0 <= idx && idx < len(errors) {
 147  		return errors[idx]
 148  	}
 149  
 150  	cache := false
 151  	switch e {
 152  	case ERROR_FILE_NOT_FOUND, ERROR_PATH_NOT_FOUND:
 153  		if cached, ok := errnoErrorCache.Load(e); ok {
 154  			return cached.(string)
 155  		}
 156  		cache = true
 157  	}
 158  
 159  	result := e.error()
 160  	if cache {
 161  		errnoErrorCache.Store(e, result)
 162  	}
 163  	return result
 164  }
 165  
 166  func (e Errno) error() string {
 167  	// ask windows for the remaining errors
 168  	var flags uint32 = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ARGUMENT_ARRAY | FORMAT_MESSAGE_IGNORE_INSERTS
 169  	b := make([]uint16, 300)
 170  	n, err := formatMessage(flags, 0, uint32(e), langid(LANG_ENGLISH, SUBLANG_ENGLISH_US), b, nil)
 171  	if err != nil {
 172  		n, err = formatMessage(flags, 0, uint32(e), 0, b, nil)
 173  		if err != nil {
 174  			return "winapi error #" + itoa.Itoa(int(e))
 175  		}
 176  	}
 177  	// trim terminating \r and \n
 178  	for ; n > 0 && (b[n-1] == '\n' || b[n-1] == '\r'); n-- {
 179  	}
 180  	return UTF16ToString(b[:n])
 181  }
 182  
 183  const (
 184  	_ERROR_NOT_ENOUGH_MEMORY    = Errno(8)
 185  	_ERROR_NOT_SUPPORTED        = Errno(50)
 186  	_ERROR_BAD_NETPATH          = Errno(53)
 187  	_ERROR_CALL_NOT_IMPLEMENTED = Errno(120)
 188  )
 189  
 190  func (e Errno) Is(target error) bool {
 191  	switch target {
 192  	case oserror.ErrPermission:
 193  		return e == ERROR_ACCESS_DENIED ||
 194  			e == EACCES ||
 195  			e == EPERM
 196  	case oserror.ErrExist:
 197  		return e == ERROR_ALREADY_EXISTS ||
 198  			e == ERROR_DIR_NOT_EMPTY ||
 199  			e == ERROR_FILE_EXISTS ||
 200  			e == EEXIST ||
 201  			e == ENOTEMPTY
 202  	case oserror.ErrNotExist:
 203  		return e == ERROR_FILE_NOT_FOUND ||
 204  			e == _ERROR_BAD_NETPATH ||
 205  			e == ERROR_PATH_NOT_FOUND ||
 206  			e == ENOENT
 207  	case errorspkg.ErrUnsupported:
 208  		return e == _ERROR_NOT_SUPPORTED ||
 209  			e == _ERROR_CALL_NOT_IMPLEMENTED ||
 210  			e == ENOSYS ||
 211  			e == ENOTSUP ||
 212  			e == EOPNOTSUPP ||
 213  			e == EWINDOWS
 214  	}
 215  	return false
 216  }
 217  
 218  func (e Errno) Temporary() bool {
 219  	return e == EINTR || e == EMFILE || e.Timeout()
 220  }
 221  
 222  func (e Errno) Timeout() bool {
 223  	return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
 224  }
 225  
 226  // Implemented in runtime/syscall_windows.go.
 227  func compileCallback(fn any, cleanstack bool) uintptr
 228  
 229  // NewCallback converts a Go function to a function pointer conforming to the stdcall calling convention.
 230  // This is useful when interoperating with Windows code requiring callbacks.
 231  // The argument is expected to be a function with one uintptr-sized result. The function must not have arguments with size larger than the size of uintptr.
 232  // Only a limited number of callbacks may be created in a single Go process, and any memory allocated
 233  // for these callbacks is never released.
 234  // Between NewCallback and NewCallbackCDecl, at least 1024 callbacks can always be created.
 235  func NewCallback(fn any) uintptr {
 236  	return compileCallback(fn, true)
 237  }
 238  
 239  // NewCallbackCDecl converts a Go function to a function pointer conforming to the cdecl calling convention.
 240  // This is useful when interoperating with Windows code requiring callbacks.
 241  // The argument is expected to be a function with one uintptr-sized result. The function must not have arguments with size larger than the size of uintptr.
 242  // Only a limited number of callbacks may be created in a single Go process, and any memory allocated
 243  // for these callbacks is never released.
 244  // Between NewCallback and NewCallbackCDecl, at least 1024 callbacks can always be created.
 245  func NewCallbackCDecl(fn any) uintptr {
 246  	return compileCallback(fn, false)
 247  }
 248  
 249  // windows api calls
 250  
 251  //sys	GetLastError() (lasterr error)
 252  //sys	LoadLibrary(libname string) (handle Handle, err error) = LoadLibraryW
 253  //sys	FreeLibrary(handle Handle) (err error)
 254  //sys	GetProcAddress(module Handle, procname string) (proc uintptr, err error)
 255  //sys	GetVersion() (ver uint32, err error)
 256  //sys	formatMessage(flags uint32, msgsrc uintptr, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) = FormatMessageW
 257  //sys	ExitProcess(exitcode uint32)
 258  //sys	createFile(name *uint16, access uint32, mode uint32, sa *SecurityAttributes, createmode uint32, attrs uint32, templatefile int32) (handle Handle, err error) [failretval == InvalidHandle || e1 == ERROR_ALREADY_EXISTS ] = CreateFileW
 259  //sys	readFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error) = ReadFile
 260  //sys	writeFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error) = WriteFile
 261  //sys	SetFilePointer(handle Handle, lowoffset int32, highoffsetptr *int32, whence uint32) (newlowoffset uint32, err error) [failretval==0xffffffff]
 262  //sys	CloseHandle(handle Handle) (err error)
 263  //sys	GetStdHandle(stdhandle int) (handle Handle, err error) [failretval==InvalidHandle]
 264  //sys	findFirstFile1(name *uint16, data *win32finddata1) (handle Handle, err error) [failretval==InvalidHandle] = FindFirstFileW
 265  //sys	findNextFile1(handle Handle, data *win32finddata1) (err error) = FindNextFileW
 266  //sys	FindClose(handle Handle) (err error)
 267  //sys	GetFileInformationByHandle(handle Handle, data *ByHandleFileInformation) (err error)
 268  //sys	GetCurrentDirectory(buflen uint32, buf *uint16) (n uint32, err error) = GetCurrentDirectoryW
 269  //sys	SetCurrentDirectory(path *uint16) (err error) = SetCurrentDirectoryW
 270  //sys	CreateDirectory(path *uint16, sa *SecurityAttributes) (err error) = CreateDirectoryW
 271  //sys	RemoveDirectory(path *uint16) (err error) = RemoveDirectoryW
 272  //sys	DeleteFile(path *uint16) (err error) = DeleteFileW
 273  //sys	MoveFile(from *uint16, to *uint16) (err error) = MoveFileW
 274  //sys	GetComputerName(buf *uint16, n *uint32) (err error) = GetComputerNameW
 275  //sys	SetEndOfFile(handle Handle) (err error)
 276  //sys	GetSystemTimeAsFileTime(time *Filetime)
 277  //sys	GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, err error) [failretval==0xffffffff]
 278  //sys	createIoCompletionPort(filehandle Handle, cphandle Handle, key uintptr, threadcnt uint32) (handle Handle, err error) = CreateIoCompletionPort
 279  //sys	getQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uintptr, overlapped **Overlapped, timeout uint32) (err error) = GetQueuedCompletionStatus
 280  //sys	postQueuedCompletionStatus(cphandle Handle, qty uint32, key uintptr, overlapped *Overlapped) (err error) = PostQueuedCompletionStatus
 281  //sys	CancelIo(s Handle) (err error)
 282  //sys	CancelIoEx(s Handle, o *Overlapped) (err error)
 283  //sys	CreateProcess(appName *uint16, commandLine *uint16, procSecurity *SecurityAttributes, threadSecurity *SecurityAttributes, inheritHandles bool, creationFlags uint32, env *uint16, currentDir *uint16, startupInfo *StartupInfo, outProcInfo *ProcessInformation) (err error) = CreateProcessW
 284  //sys	CreateProcessAsUser(token Token, appName *uint16, commandLine *uint16, procSecurity *SecurityAttributes, threadSecurity *SecurityAttributes, inheritHandles bool, creationFlags uint32, env *uint16, currentDir *uint16, startupInfo *StartupInfo, outProcInfo *ProcessInformation) (err error) = advapi32.CreateProcessAsUserW
 285  //sys	OpenProcess(da uint32, inheritHandle bool, pid uint32) (handle Handle, err error)
 286  //sys	TerminateProcess(handle Handle, exitcode uint32) (err error)
 287  //sys	GetExitCodeProcess(handle Handle, exitcode *uint32) (err error)
 288  //sys	getStartupInfo(startupInfo *StartupInfo) = GetStartupInfoW
 289  //sys	GetCurrentProcess() (pseudoHandle Handle, err error)
 290  //sys	GetProcessTimes(handle Handle, creationTime *Filetime, exitTime *Filetime, kernelTime *Filetime, userTime *Filetime) (err error)
 291  //sys	DuplicateHandle(hSourceProcessHandle Handle, hSourceHandle Handle, hTargetProcessHandle Handle, lpTargetHandle *Handle, dwDesiredAccess uint32, bInheritHandle bool, dwOptions uint32) (err error)
 292  //sys	WaitForSingleObject(handle Handle, waitMilliseconds uint32) (event uint32, err error) [failretval==0xffffffff]
 293  //sys	GetTempPath(buflen uint32, buf *uint16) (n uint32, err error) = GetTempPathW
 294  //sys	CreatePipe(readhandle *Handle, writehandle *Handle, sa *SecurityAttributes, size uint32) (err error)
 295  //sys	GetFileType(filehandle Handle) (n uint32, err error)
 296  //sys	CryptAcquireContext(provhandle *Handle, container *uint16, provider *uint16, provtype uint32, flags uint32) (err error) = advapi32.CryptAcquireContextW
 297  //sys	CryptReleaseContext(provhandle Handle, flags uint32) (err error) = advapi32.CryptReleaseContext
 298  //sys	CryptGenRandom(provhandle Handle, buflen uint32, buf *byte) (err error) = advapi32.CryptGenRandom
 299  //sys	GetEnvironmentStrings() (envs *uint16, err error) [failretval==nil] = kernel32.GetEnvironmentStringsW
 300  //sys	FreeEnvironmentStrings(envs *uint16) (err error) = kernel32.FreeEnvironmentStringsW
 301  //sys	GetEnvironmentVariable(name *uint16, buffer *uint16, size uint32) (n uint32, err error) = kernel32.GetEnvironmentVariableW
 302  //sys	SetEnvironmentVariable(name *uint16, value *uint16) (err error) = kernel32.SetEnvironmentVariableW
 303  //sys	SetFileTime(handle Handle, ctime *Filetime, atime *Filetime, wtime *Filetime) (err error)
 304  //sys	GetFileAttributes(name *uint16) (attrs uint32, err error) [failretval==INVALID_FILE_ATTRIBUTES] = kernel32.GetFileAttributesW
 305  //sys	SetFileAttributes(name *uint16, attrs uint32) (err error) = kernel32.SetFileAttributesW
 306  //sys	GetFileAttributesEx(name *uint16, level uint32, info *byte) (err error) = kernel32.GetFileAttributesExW
 307  //sys	GetCommandLine() (cmd *uint16) = kernel32.GetCommandLineW
 308  //sys	CommandLineToArgv(cmd *uint16, argc *int32) (argv *[8192]*[8192]uint16, err error) [failretval==nil] = shell32.CommandLineToArgvW
 309  //sys	LocalFree(hmem Handle) (handle Handle, err error) [failretval!=0]
 310  //sys	localAlloc(flags uint32, length uint32) (ptr uintptr, err error) = kernel32.LocalAlloc
 311  //sys	SetHandleInformation(handle Handle, mask uint32, flags uint32) (err error)
 312  //sys	FlushFileBuffers(handle Handle) (err error)
 313  //sys	GetFullPathName(path *uint16, buflen uint32, buf *uint16, fname **uint16) (n uint32, err error) = kernel32.GetFullPathNameW
 314  //sys	GetLongPathName(path *uint16, buf *uint16, buflen uint32) (n uint32, err error) = kernel32.GetLongPathNameW
 315  //sys	GetShortPathName(longpath *uint16, shortpath *uint16, buflen uint32) (n uint32, err error) = kernel32.GetShortPathNameW
 316  //sys	CreateFileMapping(fhandle Handle, sa *SecurityAttributes, prot uint32, maxSizeHigh uint32, maxSizeLow uint32, name *uint16) (handle Handle, err error) = kernel32.CreateFileMappingW
 317  //sys	MapViewOfFile(handle Handle, access uint32, offsetHigh uint32, offsetLow uint32, length uintptr) (addr uintptr, err error)
 318  //sys	UnmapViewOfFile(addr uintptr) (err error)
 319  //sys	FlushViewOfFile(addr uintptr, length uintptr) (err error)
 320  //sys	VirtualLock(addr uintptr, length uintptr) (err error)
 321  //sys	VirtualUnlock(addr uintptr, length uintptr) (err error)
 322  //sys	TransmitFile(s Handle, handle Handle, bytesToWrite uint32, bytsPerSend uint32, overlapped *Overlapped, transmitFileBuf *TransmitFileBuffers, flags uint32) (err error) = mswsock.TransmitFile
 323  //sys	ReadDirectoryChanges(handle Handle, buf *byte, buflen uint32, watchSubTree bool, mask uint32, retlen *uint32, overlapped *Overlapped, completionRoutine uintptr) (err error) = kernel32.ReadDirectoryChangesW
 324  //sys	CertOpenSystemStore(hprov Handle, name *uint16) (store Handle, err error) = crypt32.CertOpenSystemStoreW
 325  //sys   CertOpenStore(storeProvider uintptr, msgAndCertEncodingType uint32, cryptProv uintptr, flags uint32, para uintptr) (handle Handle, err error) = crypt32.CertOpenStore
 326  //sys	CertEnumCertificatesInStore(store Handle, prevContext *CertContext) (context *CertContext, err error) [failretval==nil] = crypt32.CertEnumCertificatesInStore
 327  //sys   CertAddCertificateContextToStore(store Handle, certContext *CertContext, addDisposition uint32, storeContext **CertContext) (err error) = crypt32.CertAddCertificateContextToStore
 328  //sys	CertCloseStore(store Handle, flags uint32) (err error) = crypt32.CertCloseStore
 329  //sys   CertGetCertificateChain(engine Handle, leaf *CertContext, time *Filetime, additionalStore Handle, para *CertChainPara, flags uint32, reserved uintptr, chainCtx **CertChainContext) (err error) = crypt32.CertGetCertificateChain
 330  //sys   CertFreeCertificateChain(ctx *CertChainContext) = crypt32.CertFreeCertificateChain
 331  //sys   CertCreateCertificateContext(certEncodingType uint32, certEncoded *byte, encodedLen uint32) (context *CertContext, err error) [failretval==nil] = crypt32.CertCreateCertificateContext
 332  //sys   CertFreeCertificateContext(ctx *CertContext) (err error) = crypt32.CertFreeCertificateContext
 333  //sys   CertVerifyCertificateChainPolicy(policyOID uintptr, chain *CertChainContext, para *CertChainPolicyPara, status *CertChainPolicyStatus) (err error) = crypt32.CertVerifyCertificateChainPolicy
 334  //sys	RegOpenKeyEx(key Handle, subkey *uint16, options uint32, desiredAccess uint32, result *Handle) (regerrno error) = advapi32.RegOpenKeyExW
 335  //sys	RegCloseKey(key Handle) (regerrno error) = advapi32.RegCloseKey
 336  //sys	RegQueryInfoKey(key Handle, class *uint16, classLen *uint32, reserved *uint32, subkeysLen *uint32, maxSubkeyLen *uint32, maxClassLen *uint32, valuesLen *uint32, maxValueNameLen *uint32, maxValueLen *uint32, saLen *uint32, lastWriteTime *Filetime) (regerrno error) = advapi32.RegQueryInfoKeyW
 337  //sys	regEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno error) = advapi32.RegEnumKeyExW
 338  //sys	RegQueryValueEx(key Handle, name *uint16, reserved *uint32, valtype *uint32, buf *byte, buflen *uint32) (regerrno error) = advapi32.RegQueryValueExW
 339  //sys	getCurrentProcessId() (pid uint32) = kernel32.GetCurrentProcessId
 340  //sys	GetConsoleMode(console Handle, mode *uint32) (err error) = kernel32.GetConsoleMode
 341  //sys	WriteConsole(console Handle, buf *uint16, towrite uint32, written *uint32, reserved *byte) (err error) = kernel32.WriteConsoleW
 342  //sys	ReadConsole(console Handle, buf *uint16, toread uint32, read *uint32, inputControl *byte) (err error) = kernel32.ReadConsoleW
 343  //sys	CreateToolhelp32Snapshot(flags uint32, processId uint32) (handle Handle, err error) [failretval==InvalidHandle] = kernel32.CreateToolhelp32Snapshot
 344  //sys	Process32First(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32FirstW
 345  //sys	Process32Next(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32NextW
 346  //sys	DeviceIoControl(handle Handle, ioControlCode uint32, inBuffer *byte, inBufferSize uint32, outBuffer *byte, outBufferSize uint32, bytesReturned *uint32, overlapped *Overlapped) (err error)
 347  //sys	setFileInformationByHandle(handle Handle, fileInformationClass uint32, buf unsafe.Pointer, bufsize uint32) (err error) = kernel32.SetFileInformationByHandle
 348  // This function returns 1 byte BOOLEAN rather than the 4 byte BOOL.
 349  //sys	CreateSymbolicLink(symlinkfilename *uint16, targetfilename *uint16, flags uint32) (err error) [failretval&0xff==0] = CreateSymbolicLinkW
 350  //sys	CreateHardLink(filename *uint16, existingfilename *uint16, reserved uintptr) (err error) [failretval&0xff==0] = CreateHardLinkW
 351  //sys	initializeProcThreadAttributeList(attrlist *_PROC_THREAD_ATTRIBUTE_LIST, attrcount uint32, flags uint32, size *uintptr) (err error) = InitializeProcThreadAttributeList
 352  //sys	deleteProcThreadAttributeList(attrlist *_PROC_THREAD_ATTRIBUTE_LIST) = DeleteProcThreadAttributeList
 353  //sys	updateProcThreadAttribute(attrlist *_PROC_THREAD_ATTRIBUTE_LIST, flags uint32, attr uintptr, value unsafe.Pointer, size uintptr, prevvalue unsafe.Pointer, returnedsize *uintptr) (err error) = UpdateProcThreadAttribute
 354  //sys	getFinalPathNameByHandle(file Handle, filePath *uint16, filePathSize uint32, flags uint32) (n uint32, err error) [n == 0 || n >= filePathSize] = kernel32.GetFinalPathNameByHandleW
 355  
 356  // syscall interface implementation for other packages
 357  
 358  func makeInheritSa() *SecurityAttributes {
 359  	var sa SecurityAttributes
 360  	sa.Length = uint32(unsafe.Sizeof(sa))
 361  	sa.InheritHandle = 1
 362  	return &sa
 363  }
 364  
 365  func Open(name string, flag int, perm uint32) (fd Handle, err error) {
 366  	if len(name) == 0 {
 367  		return InvalidHandle, ERROR_FILE_NOT_FOUND
 368  	}
 369  	namep, err := UTF16PtrFromString(name)
 370  	if err != nil {
 371  		return InvalidHandle, err
 372  	}
 373  	accessFlags := flag & (O_RDONLY | O_WRONLY | O_RDWR)
 374  	var access uint32
 375  	switch accessFlags {
 376  	case O_RDONLY:
 377  		access = GENERIC_READ
 378  	case O_WRONLY:
 379  		access = GENERIC_WRITE
 380  	case O_RDWR:
 381  		access = GENERIC_READ | GENERIC_WRITE
 382  	}
 383  	if flag&O_CREAT != 0 {
 384  		access |= GENERIC_WRITE
 385  	}
 386  	if flag&O_APPEND != 0 {
 387  		// Remove GENERIC_WRITE unless O_TRUNC is set, in which case we need it to truncate the file.
 388  		// We can't just remove FILE_WRITE_DATA because GENERIC_WRITE without FILE_WRITE_DATA
 389  		// starts appending at the beginning of the file rather than at the end.
 390  		if flag&O_TRUNC == 0 {
 391  			access &^= GENERIC_WRITE
 392  		}
 393  		// Set all access rights granted by GENERIC_WRITE except for FILE_WRITE_DATA.
 394  		access |= FILE_APPEND_DATA | FILE_WRITE_ATTRIBUTES | _FILE_WRITE_EA | STANDARD_RIGHTS_WRITE | SYNCHRONIZE
 395  	}
 396  	sharemode := uint32(FILE_SHARE_READ | FILE_SHARE_WRITE)
 397  	var sa *SecurityAttributes
 398  	if flag&O_CLOEXEC == 0 {
 399  		sa = makeInheritSa()
 400  	}
 401  	var attrs uint32 = FILE_ATTRIBUTE_NORMAL
 402  	if perm&S_IWRITE == 0 {
 403  		attrs = FILE_ATTRIBUTE_READONLY
 404  	}
 405  	switch accessFlags {
 406  	case O_WRONLY, O_RDWR:
 407  		// Unix doesn't allow opening a directory with O_WRONLY
 408  		// or O_RDWR, so we don't set the flag in that case,
 409  		// which will make CreateFile fail with ERROR_ACCESS_DENIED.
 410  		// We will map that to EISDIR if the file is a directory.
 411  	default:
 412  		// We might be opening a directory for reading,
 413  		// and CreateFile requires FILE_FLAG_BACKUP_SEMANTICS
 414  		// to work with directories.
 415  		attrs |= FILE_FLAG_BACKUP_SEMANTICS
 416  	}
 417  	if flag&O_SYNC != 0 {
 418  		const _FILE_FLAG_WRITE_THROUGH = 0x80000000
 419  		attrs |= _FILE_FLAG_WRITE_THROUGH
 420  	}
 421  	// We don't use CREATE_ALWAYS, because when opening a file with
 422  	// FILE_ATTRIBUTE_READONLY these will replace an existing file
 423  	// with a new, read-only one. See https://go.dev/issue/38225.
 424  	//
 425  	// Instead, we ftruncate the file after opening when O_TRUNC is set.
 426  	var createmode uint32
 427  	switch {
 428  	case flag&(O_CREAT|O_EXCL) == (O_CREAT | O_EXCL):
 429  		createmode = CREATE_NEW
 430  		attrs |= FILE_FLAG_OPEN_REPARSE_POINT // don't follow symlinks
 431  	case flag&O_CREAT == O_CREAT:
 432  		createmode = OPEN_ALWAYS
 433  	default:
 434  		createmode = OPEN_EXISTING
 435  	}
 436  	h, err := createFile(namep, access, sharemode, sa, createmode, attrs, 0)
 437  	if h == InvalidHandle {
 438  		if err == ERROR_ACCESS_DENIED && (attrs&FILE_FLAG_BACKUP_SEMANTICS == 0) {
 439  			// We should return EISDIR when we are trying to open a directory with write access.
 440  			fa, e1 := GetFileAttributes(namep)
 441  			if e1 == nil && fa&FILE_ATTRIBUTE_DIRECTORY != 0 {
 442  				err = EISDIR
 443  			}
 444  		}
 445  		return h, err
 446  	}
 447  	// Ignore O_TRUNC if the file has just been created.
 448  	if flag&O_TRUNC == O_TRUNC &&
 449  		(createmode == OPEN_EXISTING || (createmode == OPEN_ALWAYS && err == ERROR_ALREADY_EXISTS)) {
 450  		err = Ftruncate(h, 0)
 451  		if err != nil {
 452  			CloseHandle(h)
 453  			return InvalidHandle, err
 454  		}
 455  	}
 456  	return h, nil
 457  }
 458  
 459  func Read(fd Handle, p []byte) (n int, err error) {
 460  	var done uint32
 461  	e := ReadFile(fd, p, &done, nil)
 462  	if e != nil {
 463  		if e == ERROR_BROKEN_PIPE {
 464  			// NOTE(brainman): work around ERROR_BROKEN_PIPE is returned on reading EOF from stdin
 465  			return 0, nil
 466  		}
 467  		return 0, e
 468  	}
 469  	return int(done), nil
 470  }
 471  
 472  func Write(fd Handle, p []byte) (n int, err error) {
 473  	var done uint32
 474  	e := WriteFile(fd, p, &done, nil)
 475  	if e != nil {
 476  		return 0, e
 477  	}
 478  	return int(done), nil
 479  }
 480  
 481  func ReadFile(fd Handle, p []byte, done *uint32, overlapped *Overlapped) error {
 482  	err := readFile(fd, p, done, overlapped)
 483  	if race.Enabled {
 484  		if *done > 0 {
 485  			race.WriteRange(unsafe.Pointer(&p[0]), int(*done))
 486  		}
 487  		race.Acquire(unsafe.Pointer(&ioSync))
 488  	}
 489  	if msan.Enabled && *done > 0 {
 490  		msan.Write(unsafe.Pointer(&p[0]), uintptr(*done))
 491  	}
 492  	if asan.Enabled && *done > 0 {
 493  		asan.Write(unsafe.Pointer(&p[0]), uintptr(*done))
 494  	}
 495  	return err
 496  }
 497  
 498  func WriteFile(fd Handle, p []byte, done *uint32, overlapped *Overlapped) error {
 499  	if race.Enabled {
 500  		race.ReleaseMerge(unsafe.Pointer(&ioSync))
 501  	}
 502  	err := writeFile(fd, p, done, overlapped)
 503  	if race.Enabled && *done > 0 {
 504  		race.ReadRange(unsafe.Pointer(&p[0]), int(*done))
 505  	}
 506  	if msan.Enabled && *done > 0 {
 507  		msan.Read(unsafe.Pointer(&p[0]), uintptr(*done))
 508  	}
 509  	if asan.Enabled && *done > 0 {
 510  		asan.Read(unsafe.Pointer(&p[0]), uintptr(*done))
 511  	}
 512  	return err
 513  }
 514  
 515  var ioSync int64
 516  
 517  var procSetFilePointerEx = modkernel32.NewProc("SetFilePointerEx")
 518  
 519  const ptrSize = unsafe.Sizeof(uintptr(0))
 520  
 521  // setFilePointerEx calls SetFilePointerEx.
 522  // See https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-setfilepointerex
 523  func setFilePointerEx(handle Handle, distToMove int64, newFilePointer *int64, whence uint32) error {
 524  	var e1 Errno
 525  	if unsafe.Sizeof(uintptr(0)) == 8 {
 526  		_, _, e1 = Syscall6(procSetFilePointerEx.Addr(), 4, uintptr(handle), uintptr(distToMove), uintptr(unsafe.Pointer(newFilePointer)), uintptr(whence), 0, 0)
 527  	} else {
 528  		// Different 32-bit systems disgaree about whether distToMove starts 8-byte aligned.
 529  		switch runtime.GOARCH {
 530  		default:
 531  			panic("unsupported 32-bit architecture")
 532  		case "386":
 533  			// distToMove is a LARGE_INTEGER, which is 64 bits.
 534  			_, _, e1 = Syscall6(procSetFilePointerEx.Addr(), 5, uintptr(handle), uintptr(distToMove), uintptr(distToMove>>32), uintptr(unsafe.Pointer(newFilePointer)), uintptr(whence), 0)
 535  		case "arm":
 536  			// distToMove must be 8-byte aligned per ARM calling convention
 537  			// https://docs.microsoft.com/en-us/cpp/build/overview-of-arm-abi-conventions#stage-c-assignment-of-arguments-to-registers-and-stack
 538  			_, _, e1 = Syscall6(procSetFilePointerEx.Addr(), 6, uintptr(handle), 0, uintptr(distToMove), uintptr(distToMove>>32), uintptr(unsafe.Pointer(newFilePointer)), uintptr(whence))
 539  		}
 540  	}
 541  	if e1 != 0 {
 542  		return errnoErr(e1)
 543  	}
 544  	return nil
 545  }
 546  
 547  func Seek(fd Handle, offset int64, whence int) (newoffset int64, err error) {
 548  	var w uint32
 549  	switch whence {
 550  	case 0:
 551  		w = FILE_BEGIN
 552  	case 1:
 553  		w = FILE_CURRENT
 554  	case 2:
 555  		w = FILE_END
 556  	}
 557  	err = setFilePointerEx(fd, offset, &newoffset, w)
 558  	return
 559  }
 560  
 561  func Close(fd Handle) (err error) {
 562  	return CloseHandle(fd)
 563  }
 564  
 565  var (
 566  	Stdin  = getStdHandle(STD_INPUT_HANDLE)
 567  	Stdout = getStdHandle(STD_OUTPUT_HANDLE)
 568  	Stderr = getStdHandle(STD_ERROR_HANDLE)
 569  )
 570  
 571  func getStdHandle(h int) (fd Handle) {
 572  	r, _ := GetStdHandle(h)
 573  	return r
 574  }
 575  
 576  const ImplementsGetwd = true
 577  
 578  func Getwd() (wd string, err error) {
 579  	b := make([]uint16, 300)
 580  	// The path of the current directory may not fit in the initial 300-word
 581  	// buffer when long path support is enabled. The current directory may also
 582  	// change between subsequent calls of GetCurrentDirectory. As a result, we
 583  	// need to retry the call in a loop until the current directory fits, each
 584  	// time with a bigger buffer.
 585  	for {
 586  		n, e := GetCurrentDirectory(uint32(len(b)), &b[0])
 587  		if e != nil {
 588  			return "", e
 589  		}
 590  		if int(n) <= len(b) {
 591  			return UTF16ToString(b[:n]), nil
 592  		}
 593  		b = make([]uint16, n)
 594  	}
 595  }
 596  
 597  func Chdir(path string) (err error) {
 598  	pathp, err := UTF16PtrFromString(path)
 599  	if err != nil {
 600  		return err
 601  	}
 602  	return SetCurrentDirectory(pathp)
 603  }
 604  
 605  func Mkdir(path string, mode uint32) (err error) {
 606  	pathp, err := UTF16PtrFromString(path)
 607  	if err != nil {
 608  		return err
 609  	}
 610  	return CreateDirectory(pathp, nil)
 611  }
 612  
 613  func Rmdir(path string) (err error) {
 614  	pathp, err := UTF16PtrFromString(path)
 615  	if err != nil {
 616  		return err
 617  	}
 618  	return RemoveDirectory(pathp)
 619  }
 620  
 621  func Unlink(path string) (err error) {
 622  	pathp, err := UTF16PtrFromString(path)
 623  	if err != nil {
 624  		return err
 625  	}
 626  	return DeleteFile(pathp)
 627  }
 628  
 629  func Rename(oldpath, newpath string) (err error) {
 630  	from, err := UTF16PtrFromString(oldpath)
 631  	if err != nil {
 632  		return err
 633  	}
 634  	to, err := UTF16PtrFromString(newpath)
 635  	if err != nil {
 636  		return err
 637  	}
 638  	return MoveFile(from, to)
 639  }
 640  
 641  func ComputerName() (name string, err error) {
 642  	var n uint32 = MAX_COMPUTERNAME_LENGTH + 1
 643  	b := make([]uint16, n)
 644  	e := GetComputerName(&b[0], &n)
 645  	if e != nil {
 646  		return "", e
 647  	}
 648  	return UTF16ToString(b[:n]), nil
 649  }
 650  
 651  func Ftruncate(fd Handle, length int64) (err error) {
 652  	type _FILE_END_OF_FILE_INFO struct {
 653  		EndOfFile int64
 654  	}
 655  	const FileEndOfFileInfo = 6
 656  	var info _FILE_END_OF_FILE_INFO
 657  	info.EndOfFile = length
 658  	return setFileInformationByHandle(fd, FileEndOfFileInfo, unsafe.Pointer(&info), uint32(unsafe.Sizeof(info)))
 659  }
 660  
 661  func Gettimeofday(tv *Timeval) (err error) {
 662  	var ft Filetime
 663  	GetSystemTimeAsFileTime(&ft)
 664  	*tv = NsecToTimeval(ft.Nanoseconds())
 665  	return nil
 666  }
 667  
 668  func Pipe(p []Handle) (err error) {
 669  	if len(p) != 2 {
 670  		return EINVAL
 671  	}
 672  	var r, w Handle
 673  	e := CreatePipe(&r, &w, makeInheritSa(), 0)
 674  	if e != nil {
 675  		return e
 676  	}
 677  	p[0] = r
 678  	p[1] = w
 679  	return nil
 680  }
 681  
 682  func Utimes(path string, tv []Timeval) (err error) {
 683  	if len(tv) != 2 {
 684  		return EINVAL
 685  	}
 686  	pathp, e := UTF16PtrFromString(path)
 687  	if e != nil {
 688  		return e
 689  	}
 690  	h, e := CreateFile(pathp,
 691  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
 692  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
 693  	if e != nil {
 694  		return e
 695  	}
 696  	defer Close(h)
 697  	a := Filetime{}
 698  	w := Filetime{}
 699  	if tv[0].Nanoseconds() != 0 {
 700  		a = NsecToFiletime(tv[0].Nanoseconds())
 701  	}
 702  	if tv[0].Nanoseconds() != 0 {
 703  		w = NsecToFiletime(tv[1].Nanoseconds())
 704  	}
 705  	return SetFileTime(h, nil, &a, &w)
 706  }
 707  
 708  // This matches the value in os/file_windows.go.
 709  const _UTIME_OMIT = -1
 710  
 711  func UtimesNano(path string, ts []Timespec) (err error) {
 712  	if len(ts) != 2 {
 713  		return EINVAL
 714  	}
 715  	pathp, e := UTF16PtrFromString(path)
 716  	if e != nil {
 717  		return e
 718  	}
 719  	h, e := CreateFile(pathp,
 720  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
 721  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
 722  	if e != nil {
 723  		return e
 724  	}
 725  	defer Close(h)
 726  	a := Filetime{}
 727  	w := Filetime{}
 728  	if ts[0].Nsec != _UTIME_OMIT {
 729  		a = NsecToFiletime(TimespecToNsec(ts[0]))
 730  	}
 731  	if ts[1].Nsec != _UTIME_OMIT {
 732  		w = NsecToFiletime(TimespecToNsec(ts[1]))
 733  	}
 734  	return SetFileTime(h, nil, &a, &w)
 735  }
 736  
 737  func Fsync(fd Handle) (err error) {
 738  	return FlushFileBuffers(fd)
 739  }
 740  
 741  func Chmod(path string, mode uint32) (err error) {
 742  	p, e := UTF16PtrFromString(path)
 743  	if e != nil {
 744  		return e
 745  	}
 746  	attrs, e := GetFileAttributes(p)
 747  	if e != nil {
 748  		return e
 749  	}
 750  	if mode&S_IWRITE != 0 {
 751  		attrs &^= FILE_ATTRIBUTE_READONLY
 752  	} else {
 753  		attrs |= FILE_ATTRIBUTE_READONLY
 754  	}
 755  	return SetFileAttributes(p, attrs)
 756  }
 757  
 758  func LoadCancelIoEx() error {
 759  	return procCancelIoEx.Find()
 760  }
 761  
 762  func LoadSetFileCompletionNotificationModes() error {
 763  	return procSetFileCompletionNotificationModes.Find()
 764  }
 765  
 766  // net api calls
 767  
 768  const socket_error = uintptr(^uint32(0))
 769  
 770  //sys	WSAStartup(verreq uint32, data *WSAData) (sockerr error) = ws2_32.WSAStartup
 771  //sys	WSACleanup() (err error) [failretval==socket_error] = ws2_32.WSACleanup
 772  //sys	WSAIoctl(s Handle, iocc uint32, inbuf *byte, cbif uint32, outbuf *byte, cbob uint32, cbbr *uint32, overlapped *Overlapped, completionRoutine uintptr) (err error) [failretval==socket_error] = ws2_32.WSAIoctl
 773  //sys	socket(af int32, typ int32, protocol int32) (handle Handle, err error) [failretval==InvalidHandle] = ws2_32.socket
 774  //sys	Setsockopt(s Handle, level int32, optname int32, optval *byte, optlen int32) (err error) [failretval==socket_error] = ws2_32.setsockopt
 775  //sys	Getsockopt(s Handle, level int32, optname int32, optval *byte, optlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockopt
 776  //sys	bind(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.bind
 777  //sys	connect(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.connect
 778  //sys	getsockname(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockname
 779  //sys	getpeername(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getpeername
 780  //sys	listen(s Handle, backlog int32) (err error) [failretval==socket_error] = ws2_32.listen
 781  //sys	shutdown(s Handle, how int32) (err error) [failretval==socket_error] = ws2_32.shutdown
 782  //sys	Closesocket(s Handle) (err error) [failretval==socket_error] = ws2_32.closesocket
 783  //sys	AcceptEx(ls Handle, as Handle, buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, recvd *uint32, overlapped *Overlapped) (err error) = mswsock.AcceptEx
 784  //sys	GetAcceptExSockaddrs(buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, lrsa **RawSockaddrAny, lrsalen *int32, rrsa **RawSockaddrAny, rrsalen *int32) = mswsock.GetAcceptExSockaddrs
 785  //sys	WSARecv(s Handle, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSARecv
 786  //sys	WSASend(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSASend
 787  //sys	WSARecvFrom(s Handle, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32,  from *RawSockaddrAny, fromlen *int32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSARecvFrom
 788  //sys	WSASendTo(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *RawSockaddrAny, tolen int32,  overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSASendTo
 789  //sys	GetHostByName(name string) (h *Hostent, err error) [failretval==nil] = ws2_32.gethostbyname
 790  //sys	GetServByName(name string, proto string) (s *Servent, err error) [failretval==nil] = ws2_32.getservbyname
 791  //sys	Ntohs(netshort uint16) (u uint16) = ws2_32.ntohs
 792  //sys	GetProtoByName(name string) (p *Protoent, err error) [failretval==nil] = ws2_32.getprotobyname
 793  //sys	DnsQuery(name string, qtype uint16, options uint32, extra *byte, qrs **DNSRecord, pr *byte) (status error) = dnsapi.DnsQuery_W
 794  //sys	DnsRecordListFree(rl *DNSRecord, freetype uint32) = dnsapi.DnsRecordListFree
 795  //sys	DnsNameCompare(name1 *uint16, name2 *uint16) (same bool) = dnsapi.DnsNameCompare_W
 796  //sys	GetAddrInfoW(nodename *uint16, servicename *uint16, hints *AddrinfoW, result **AddrinfoW) (sockerr error) = ws2_32.GetAddrInfoW
 797  //sys	FreeAddrInfoW(addrinfo *AddrinfoW) = ws2_32.FreeAddrInfoW
 798  //sys	GetIfEntry(pIfRow *MibIfRow) (errcode error) = iphlpapi.GetIfEntry
 799  //sys	GetAdaptersInfo(ai *IpAdapterInfo, ol *uint32) (errcode error) = iphlpapi.GetAdaptersInfo
 800  //sys	SetFileCompletionNotificationModes(handle Handle, flags uint8) (err error) = kernel32.SetFileCompletionNotificationModes
 801  //sys	WSAEnumProtocols(protocols *int32, protocolBuffer *WSAProtocolInfo, bufferLength *uint32) (n int32, err error) [failretval==-1] = ws2_32.WSAEnumProtocolsW
 802  
 803  // For testing: clients can set this flag to force
 804  // creation of IPv6 sockets to return [EAFNOSUPPORT].
 805  var SocketDisableIPv6 bool
 806  
 807  type RawSockaddrInet4 struct {
 808  	Family uint16
 809  	Port   uint16
 810  	Addr   [4]byte /* in_addr */
 811  	Zero   [8]uint8
 812  }
 813  
 814  type RawSockaddrInet6 struct {
 815  	Family   uint16
 816  	Port     uint16
 817  	Flowinfo uint32
 818  	Addr     [16]byte /* in6_addr */
 819  	Scope_id uint32
 820  }
 821  
 822  type RawSockaddr struct {
 823  	Family uint16
 824  	Data   [14]int8
 825  }
 826  
 827  type RawSockaddrAny struct {
 828  	Addr RawSockaddr
 829  	Pad  [100]int8
 830  }
 831  
 832  type Sockaddr interface {
 833  	sockaddr() (ptr unsafe.Pointer, len int32, err error) // lowercase; only we can define Sockaddrs
 834  }
 835  
 836  type SockaddrInet4 struct {
 837  	Port int
 838  	Addr [4]byte
 839  	raw  RawSockaddrInet4
 840  }
 841  
 842  func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, int32, error) {
 843  	if sa.Port < 0 || sa.Port > 0xFFFF {
 844  		return nil, 0, EINVAL
 845  	}
 846  	sa.raw.Family = AF_INET
 847  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
 848  	p[0] = byte(sa.Port >> 8)
 849  	p[1] = byte(sa.Port)
 850  	sa.raw.Addr = sa.Addr
 851  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
 852  }
 853  
 854  type SockaddrInet6 struct {
 855  	Port   int
 856  	ZoneId uint32
 857  	Addr   [16]byte
 858  	raw    RawSockaddrInet6
 859  }
 860  
 861  func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, int32, error) {
 862  	if sa.Port < 0 || sa.Port > 0xFFFF {
 863  		return nil, 0, EINVAL
 864  	}
 865  	sa.raw.Family = AF_INET6
 866  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
 867  	p[0] = byte(sa.Port >> 8)
 868  	p[1] = byte(sa.Port)
 869  	sa.raw.Scope_id = sa.ZoneId
 870  	sa.raw.Addr = sa.Addr
 871  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
 872  }
 873  
 874  type RawSockaddrUnix struct {
 875  	Family uint16
 876  	Path   [UNIX_PATH_MAX]int8
 877  }
 878  
 879  type SockaddrUnix struct {
 880  	Name string
 881  	raw  RawSockaddrUnix
 882  }
 883  
 884  func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, int32, error) {
 885  	name := sa.Name
 886  	n := len(name)
 887  	if n > len(sa.raw.Path) {
 888  		return nil, 0, EINVAL
 889  	}
 890  	// Abstract addresses start with NUL.
 891  	// '@' is also a valid way to specify abstract addresses.
 892  	isAbstract := n > 0 && (name[0] == '@' || name[0] == '\x00')
 893  
 894  	// Non-abstract named addresses are NUL terminated.
 895  	// The length can't use the full capacity as we need to add NUL.
 896  	if n == len(sa.raw.Path) && !isAbstract {
 897  		return nil, 0, EINVAL
 898  	}
 899  	sa.raw.Family = AF_UNIX
 900  	for i := 0; i < n; i++ {
 901  		sa.raw.Path[i] = int8(name[i])
 902  	}
 903  	// Length is family + name (+ NUL if non-abstract).
 904  	// Family is of type uint16 (2 bytes).
 905  	sl := int32(2 + n)
 906  	if isAbstract {
 907  		// Abstract addresses are not NUL terminated.
 908  		// We rewrite '@' prefix to NUL here.
 909  		sa.raw.Path[0] = 0
 910  	} else if n > 0 {
 911  		// Add NUL for non-abstract named addresses.
 912  		sl++
 913  	}
 914  
 915  	return unsafe.Pointer(&sa.raw), sl, nil
 916  }
 917  
 918  func (rsa *RawSockaddrAny) Sockaddr() (Sockaddr, error) {
 919  	switch rsa.Addr.Family {
 920  	case AF_UNIX:
 921  		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
 922  		sa := new(SockaddrUnix)
 923  		if pp.Path[0] == 0 {
 924  			// "Abstract" Unix domain socket.
 925  			// Rewrite leading NUL as @ for textual display.
 926  			// (This is the standard convention.)
 927  			// Not friendly to overwrite in place,
 928  			// but the callers below don't care.
 929  			pp.Path[0] = '@'
 930  		}
 931  
 932  		// Assume path ends at NUL.
 933  		// This is not technically the Linux semantics for
 934  		// abstract Unix domain sockets--they are supposed
 935  		// to be uninterpreted fixed-size binary blobs--but
 936  		// everyone uses this convention.
 937  		n := 0
 938  		for n < len(pp.Path) && pp.Path[n] != 0 {
 939  			n++
 940  		}
 941  		sa.Name = string(unsafe.Slice((*byte)(unsafe.Pointer(&pp.Path[0])), n))
 942  		return sa, nil
 943  
 944  	case AF_INET:
 945  		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
 946  		sa := new(SockaddrInet4)
 947  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
 948  		sa.Port = int(p[0])<<8 + int(p[1])
 949  		sa.Addr = pp.Addr
 950  		return sa, nil
 951  
 952  	case AF_INET6:
 953  		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
 954  		sa := new(SockaddrInet6)
 955  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
 956  		sa.Port = int(p[0])<<8 + int(p[1])
 957  		sa.ZoneId = pp.Scope_id
 958  		sa.Addr = pp.Addr
 959  		return sa, nil
 960  	}
 961  	return nil, EAFNOSUPPORT
 962  }
 963  
 964  func Socket(domain, typ, proto int) (fd Handle, err error) {
 965  	if domain == AF_INET6 && SocketDisableIPv6 {
 966  		return InvalidHandle, EAFNOSUPPORT
 967  	}
 968  	return socket(int32(domain), int32(typ), int32(proto))
 969  }
 970  
 971  func SetsockoptInt(fd Handle, level, opt int, value int) (err error) {
 972  	v := int32(value)
 973  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&v)), int32(unsafe.Sizeof(v)))
 974  }
 975  
 976  func Bind(fd Handle, sa Sockaddr) (err error) {
 977  	ptr, n, err := sa.sockaddr()
 978  	if err != nil {
 979  		return err
 980  	}
 981  	return bind(fd, ptr, n)
 982  }
 983  
 984  func Connect(fd Handle, sa Sockaddr) (err error) {
 985  	ptr, n, err := sa.sockaddr()
 986  	if err != nil {
 987  		return err
 988  	}
 989  	return connect(fd, ptr, n)
 990  }
 991  
 992  func Getsockname(fd Handle) (sa Sockaddr, err error) {
 993  	var rsa RawSockaddrAny
 994  	l := int32(unsafe.Sizeof(rsa))
 995  	if err = getsockname(fd, &rsa, &l); err != nil {
 996  		return
 997  	}
 998  	return rsa.Sockaddr()
 999  }
1000  
1001  func Getpeername(fd Handle) (sa Sockaddr, err error) {
1002  	var rsa RawSockaddrAny
1003  	l := int32(unsafe.Sizeof(rsa))
1004  	if err = getpeername(fd, &rsa, &l); err != nil {
1005  		return
1006  	}
1007  	return rsa.Sockaddr()
1008  }
1009  
1010  func Listen(s Handle, n int) (err error) {
1011  	return listen(s, int32(n))
1012  }
1013  
1014  func Shutdown(fd Handle, how int) (err error) {
1015  	return shutdown(fd, int32(how))
1016  }
1017  
1018  func WSASendto(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to Sockaddr, overlapped *Overlapped, croutine *byte) (err error) {
1019  	var rsa unsafe.Pointer
1020  	var len int32
1021  	if to != nil {
1022  		rsa, len, err = to.sockaddr()
1023  		if err != nil {
1024  			return err
1025  		}
1026  	}
1027  	r1, _, e1 := Syscall9(procWSASendTo.Addr(), 9, uintptr(s), uintptr(unsafe.Pointer(bufs)), uintptr(bufcnt), uintptr(unsafe.Pointer(sent)), uintptr(flags), uintptr(unsafe.Pointer(rsa)), uintptr(len), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(croutine)))
1028  	if r1 == socket_error {
1029  		if e1 != 0 {
1030  			err = errnoErr(e1)
1031  		} else {
1032  			err = EINVAL
1033  		}
1034  	}
1035  	return err
1036  }
1037  
1038  func wsaSendtoInet4(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *SockaddrInet4, overlapped *Overlapped, croutine *byte) (err error) {
1039  	rsa, len, err := to.sockaddr()
1040  	if err != nil {
1041  		return err
1042  	}
1043  	r1, _, e1 := Syscall9(procWSASendTo.Addr(), 9, uintptr(s), uintptr(unsafe.Pointer(bufs)), uintptr(bufcnt), uintptr(unsafe.Pointer(sent)), uintptr(flags), uintptr(unsafe.Pointer(rsa)), uintptr(len), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(croutine)))
1044  	if r1 == socket_error {
1045  		if e1 != 0 {
1046  			err = errnoErr(e1)
1047  		} else {
1048  			err = EINVAL
1049  		}
1050  	}
1051  	return err
1052  }
1053  
1054  func wsaSendtoInet6(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *SockaddrInet6, overlapped *Overlapped, croutine *byte) (err error) {
1055  	rsa, len, err := to.sockaddr()
1056  	if err != nil {
1057  		return err
1058  	}
1059  	r1, _, e1 := Syscall9(procWSASendTo.Addr(), 9, uintptr(s), uintptr(unsafe.Pointer(bufs)), uintptr(bufcnt), uintptr(unsafe.Pointer(sent)), uintptr(flags), uintptr(unsafe.Pointer(rsa)), uintptr(len), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(croutine)))
1060  	if r1 == socket_error {
1061  		if e1 != 0 {
1062  			err = errnoErr(e1)
1063  		} else {
1064  			err = EINVAL
1065  		}
1066  	}
1067  	return err
1068  }
1069  
1070  func LoadGetAddrInfo() error {
1071  	return procGetAddrInfoW.Find()
1072  }
1073  
1074  var connectExFunc struct {
1075  	once sync.Once
1076  	addr uintptr
1077  	err  error
1078  }
1079  
1080  func LoadConnectEx() error {
1081  	connectExFunc.once.Do(func() {
1082  		var s Handle
1083  		s, connectExFunc.err = Socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)
1084  		if connectExFunc.err != nil {
1085  			return
1086  		}
1087  		defer CloseHandle(s)
1088  		var n uint32
1089  		connectExFunc.err = WSAIoctl(s,
1090  			SIO_GET_EXTENSION_FUNCTION_POINTER,
1091  			(*byte)(unsafe.Pointer(&WSAID_CONNECTEX)),
1092  			uint32(unsafe.Sizeof(WSAID_CONNECTEX)),
1093  			(*byte)(unsafe.Pointer(&connectExFunc.addr)),
1094  			uint32(unsafe.Sizeof(connectExFunc.addr)),
1095  			&n, nil, 0)
1096  	})
1097  	return connectExFunc.err
1098  }
1099  
1100  func connectEx(s Handle, name unsafe.Pointer, namelen int32, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) (err error) {
1101  	r1, _, e1 := Syscall9(connectExFunc.addr, 7, uintptr(s), uintptr(name), uintptr(namelen), uintptr(unsafe.Pointer(sendBuf)), uintptr(sendDataLen), uintptr(unsafe.Pointer(bytesSent)), uintptr(unsafe.Pointer(overlapped)), 0, 0)
1102  	if r1 == 0 {
1103  		if e1 != 0 {
1104  			err = error(e1)
1105  		} else {
1106  			err = EINVAL
1107  		}
1108  	}
1109  	return
1110  }
1111  
1112  func ConnectEx(fd Handle, sa Sockaddr, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) error {
1113  	err := LoadConnectEx()
1114  	if err != nil {
1115  		return errorspkg.New("failed to find ConnectEx: " + err.Error())
1116  	}
1117  	ptr, n, err := sa.sockaddr()
1118  	if err != nil {
1119  		return err
1120  	}
1121  	return connectEx(fd, ptr, n, sendBuf, sendDataLen, bytesSent, overlapped)
1122  }
1123  
1124  // Invented structures to support what package os expects.
1125  type Rusage struct {
1126  	CreationTime Filetime
1127  	ExitTime     Filetime
1128  	KernelTime   Filetime
1129  	UserTime     Filetime
1130  }
1131  
1132  type WaitStatus struct {
1133  	ExitCode uint32
1134  }
1135  
1136  func (w WaitStatus) Exited() bool { return true }
1137  
1138  func (w WaitStatus) ExitStatus() int { return int(w.ExitCode) }
1139  
1140  func (w WaitStatus) Signal() Signal { return -1 }
1141  
1142  func (w WaitStatus) CoreDump() bool { return false }
1143  
1144  func (w WaitStatus) Stopped() bool { return false }
1145  
1146  func (w WaitStatus) Continued() bool { return false }
1147  
1148  func (w WaitStatus) StopSignal() Signal { return -1 }
1149  
1150  func (w WaitStatus) Signaled() bool { return false }
1151  
1152  func (w WaitStatus) TrapCause() int { return -1 }
1153  
1154  // Timespec is an invented structure on Windows, but here for
1155  // consistency with the syscall package for other operating systems.
1156  type Timespec struct {
1157  	Sec  int64
1158  	Nsec int64
1159  }
1160  
1161  func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
1162  
1163  func NsecToTimespec(nsec int64) (ts Timespec) {
1164  	ts.Sec = nsec / 1e9
1165  	ts.Nsec = nsec % 1e9
1166  	return
1167  }
1168  
1169  // TODO(brainman): fix all needed for net
1170  
1171  func Accept(fd Handle) (nfd Handle, sa Sockaddr, err error) { return 0, nil, EWINDOWS }
1172  func Recvfrom(fd Handle, p []byte, flags int) (n int, from Sockaddr, err error) {
1173  	return 0, nil, EWINDOWS
1174  }
1175  func Sendto(fd Handle, p []byte, flags int, to Sockaddr) (err error)       { return EWINDOWS }
1176  func SetsockoptTimeval(fd Handle, level, opt int, tv *Timeval) (err error) { return EWINDOWS }
1177  
1178  // The Linger struct is wrong but we only noticed after Go 1.
1179  // sysLinger is the real system call structure.
1180  
1181  // BUG(brainman): The definition of Linger is not appropriate for direct use
1182  // with Setsockopt and Getsockopt.
1183  // Use SetsockoptLinger instead.
1184  
1185  type Linger struct {
1186  	Onoff  int32
1187  	Linger int32
1188  }
1189  
1190  type sysLinger struct {
1191  	Onoff  uint16
1192  	Linger uint16
1193  }
1194  
1195  type IPMreq struct {
1196  	Multiaddr [4]byte /* in_addr */
1197  	Interface [4]byte /* in_addr */
1198  }
1199  
1200  type IPv6Mreq struct {
1201  	Multiaddr [16]byte /* in6_addr */
1202  	Interface uint32
1203  }
1204  
1205  func GetsockoptInt(fd Handle, level, opt int) (int, error) {
1206  	optval := int32(0)
1207  	optlen := int32(unsafe.Sizeof(optval))
1208  	err := Getsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&optval)), &optlen)
1209  	return int(optval), err
1210  }
1211  
1212  func SetsockoptLinger(fd Handle, level, opt int, l *Linger) (err error) {
1213  	sys := sysLinger{Onoff: uint16(l.Onoff), Linger: uint16(l.Linger)}
1214  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&sys)), int32(unsafe.Sizeof(sys)))
1215  }
1216  
1217  func SetsockoptInet4Addr(fd Handle, level, opt int, value [4]byte) (err error) {
1218  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&value[0])), 4)
1219  }
1220  func SetsockoptIPMreq(fd Handle, level, opt int, mreq *IPMreq) (err error) {
1221  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(mreq)), int32(unsafe.Sizeof(*mreq)))
1222  }
1223  func SetsockoptIPv6Mreq(fd Handle, level, opt int, mreq *IPv6Mreq) (err error) {
1224  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(mreq)), int32(unsafe.Sizeof(*mreq)))
1225  }
1226  
1227  func Getpid() (pid int) { return int(getCurrentProcessId()) }
1228  
1229  func FindFirstFile(name *uint16, data *Win32finddata) (handle Handle, err error) {
1230  	// NOTE(rsc): The Win32finddata struct is wrong for the system call:
1231  	// the two paths are each one uint16 short. Use the correct struct,
1232  	// a win32finddata1, and then copy the results out.
1233  	// There is no loss of expressivity here, because the final
1234  	// uint16, if it is used, is supposed to be a NUL, and Go doesn't need that.
1235  	// For Go 1.1, we might avoid the allocation of win32finddata1 here
1236  	// by adding a final Bug [2]uint16 field to the struct and then
1237  	// adjusting the fields in the result directly.
1238  	var data1 win32finddata1
1239  	handle, err = findFirstFile1(name, &data1)
1240  	if err == nil {
1241  		copyFindData(data, &data1)
1242  	}
1243  	return
1244  }
1245  
1246  func FindNextFile(handle Handle, data *Win32finddata) (err error) {
1247  	var data1 win32finddata1
1248  	err = findNextFile1(handle, &data1)
1249  	if err == nil {
1250  		copyFindData(data, &data1)
1251  	}
1252  	return
1253  }
1254  
1255  func getProcessEntry(pid int) (*ProcessEntry32, error) {
1256  	snapshot, err := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)
1257  	if err != nil {
1258  		return nil, err
1259  	}
1260  	defer CloseHandle(snapshot)
1261  	var procEntry ProcessEntry32
1262  	procEntry.Size = uint32(unsafe.Sizeof(procEntry))
1263  	if err = Process32First(snapshot, &procEntry); err != nil {
1264  		return nil, err
1265  	}
1266  	for {
1267  		if procEntry.ProcessID == uint32(pid) {
1268  			return &procEntry, nil
1269  		}
1270  		err = Process32Next(snapshot, &procEntry)
1271  		if err != nil {
1272  			return nil, err
1273  		}
1274  	}
1275  }
1276  
1277  func Getppid() (ppid int) {
1278  	pe, err := getProcessEntry(Getpid())
1279  	if err != nil {
1280  		return -1
1281  	}
1282  	return int(pe.ParentProcessID)
1283  }
1284  
1285  func fdpath(fd Handle, buf []uint16) ([]uint16, error) {
1286  	const (
1287  		FILE_NAME_NORMALIZED = 0
1288  		VOLUME_NAME_DOS      = 0
1289  	)
1290  	for {
1291  		n, err := getFinalPathNameByHandle(fd, &buf[0], uint32(len(buf)), FILE_NAME_NORMALIZED|VOLUME_NAME_DOS)
1292  		if err == nil {
1293  			buf = buf[:n]
1294  			break
1295  		}
1296  		if err != _ERROR_NOT_ENOUGH_MEMORY {
1297  			return nil, err
1298  		}
1299  		buf = append(buf, make([]uint16, n-uint32(len(buf)))...)
1300  	}
1301  	return buf, nil
1302  }
1303  
1304  func Fchdir(fd Handle) (err error) {
1305  	var buf [MAX_PATH + 1]uint16
1306  	path, err := fdpath(fd, buf[:])
1307  	if err != nil {
1308  		return err
1309  	}
1310  	// When using VOLUME_NAME_DOS, the path is always prefixed by "\\?\".
1311  	// That prefix tells the Windows APIs to disable all string parsing and to send
1312  	// the string that follows it straight to the file system.
1313  	// Although SetCurrentDirectory and GetCurrentDirectory do support the "\\?\" prefix,
1314  	// some other Windows APIs don't. If the prefix is not removed here, it will leak
1315  	// to Getwd, and we don't want such a general-purpose function to always return a
1316  	// path with the "\\?\" prefix after Fchdir is called.
1317  	// The downside is that APIs that do support it will parse the path and try to normalize it,
1318  	// when it's already normalized.
1319  	if len(path) >= 4 && path[0] == '\\' && path[1] == '\\' && path[2] == '?' && path[3] == '\\' {
1320  		path = path[4:]
1321  	}
1322  	return SetCurrentDirectory(&path[0])
1323  }
1324  
1325  // TODO(brainman): fix all needed for os
1326  func Link(oldpath, newpath string) (err error) { return EWINDOWS }
1327  func Symlink(path, link string) (err error)    { return EWINDOWS }
1328  
1329  func Fchmod(fd Handle, mode uint32) (err error)        { return EWINDOWS }
1330  func Chown(path string, uid int, gid int) (err error)  { return EWINDOWS }
1331  func Lchown(path string, uid int, gid int) (err error) { return EWINDOWS }
1332  func Fchown(fd Handle, uid int, gid int) (err error)   { return EWINDOWS }
1333  
1334  func Getuid() (uid int)                  { return -1 }
1335  func Geteuid() (euid int)                { return -1 }
1336  func Getgid() (gid int)                  { return -1 }
1337  func Getegid() (egid int)                { return -1 }
1338  func Getgroups() (gids []int, err error) { return nil, EWINDOWS }
1339  
1340  type Signal int
1341  
1342  func (s Signal) Signal() {}
1343  
1344  func (s Signal) String() string {
1345  	if 0 <= s && int(s) < len(signals) {
1346  		str := signals[s]
1347  		if str != "" {
1348  			return str
1349  		}
1350  	}
1351  	return "signal " + itoa.Itoa(int(s))
1352  }
1353  
1354  func LoadCreateSymbolicLink() error {
1355  	return procCreateSymbolicLinkW.Find()
1356  }
1357  
1358  // Readlink returns the destination of the named symbolic link.
1359  func Readlink(path string, buf []byte) (n int, err error) {
1360  	fd, err := CreateFile(StringToUTF16Ptr(path), GENERIC_READ, 0, nil, OPEN_EXISTING,
1361  		FILE_FLAG_OPEN_REPARSE_POINT|FILE_FLAG_BACKUP_SEMANTICS, 0)
1362  	if err != nil {
1363  		return -1, err
1364  	}
1365  	defer CloseHandle(fd)
1366  
1367  	rdbbuf := make([]byte, MAXIMUM_REPARSE_DATA_BUFFER_SIZE)
1368  	var bytesReturned uint32
1369  	err = DeviceIoControl(fd, FSCTL_GET_REPARSE_POINT, nil, 0, &rdbbuf[0], uint32(len(rdbbuf)), &bytesReturned, nil)
1370  	if err != nil {
1371  		return -1, err
1372  	}
1373  
1374  	rdb := (*reparseDataBuffer)(unsafe.Pointer(&rdbbuf[0]))
1375  	var s string
1376  	switch rdb.ReparseTag {
1377  	case IO_REPARSE_TAG_SYMLINK:
1378  		data := (*symbolicLinkReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
1379  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
1380  		s = UTF16ToString(p[data.SubstituteNameOffset/2 : (data.SubstituteNameOffset+data.SubstituteNameLength)/2])
1381  		if data.Flags&_SYMLINK_FLAG_RELATIVE == 0 {
1382  			if len(s) >= 4 && s[:4] == `\??\` {
1383  				s = s[4:]
1384  				switch {
1385  				case len(s) >= 2 && s[1] == ':': // \??\C:\foo\bar
1386  					// do nothing
1387  				case len(s) >= 4 && s[:4] == `UNC\`: // \??\UNC\foo\bar
1388  					s = `\\` + s[4:]
1389  				default:
1390  					// unexpected; do nothing
1391  				}
1392  			} else {
1393  				// unexpected; do nothing
1394  			}
1395  		}
1396  	case _IO_REPARSE_TAG_MOUNT_POINT:
1397  		data := (*mountPointReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
1398  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
1399  		s = UTF16ToString(p[data.SubstituteNameOffset/2 : (data.SubstituteNameOffset+data.SubstituteNameLength)/2])
1400  		if len(s) >= 4 && s[:4] == `\??\` { // \??\C:\foo\bar
1401  			s = s[4:]
1402  		} else {
1403  			// unexpected; do nothing
1404  		}
1405  	default:
1406  		// the path is not a symlink or junction but another type of reparse
1407  		// point
1408  		return -1, ENOENT
1409  	}
1410  	n = copy(buf, []byte(s))
1411  
1412  	return n, nil
1413  }
1414  
1415  // Deprecated: CreateIoCompletionPort has the wrong function signature. Use x/sys/windows.CreateIoCompletionPort.
1416  func CreateIoCompletionPort(filehandle Handle, cphandle Handle, key uint32, threadcnt uint32) (Handle, error) {
1417  	return createIoCompletionPort(filehandle, cphandle, uintptr(key), threadcnt)
1418  }
1419  
1420  // Deprecated: GetQueuedCompletionStatus has the wrong function signature. Use x/sys/windows.GetQueuedCompletionStatus.
1421  func GetQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uint32, overlapped **Overlapped, timeout uint32) error {
1422  	var ukey uintptr
1423  	var pukey *uintptr
1424  	if key != nil {
1425  		ukey = uintptr(*key)
1426  		pukey = &ukey
1427  	}
1428  	err := getQueuedCompletionStatus(cphandle, qty, pukey, overlapped, timeout)
1429  	if key != nil {
1430  		*key = uint32(ukey)
1431  		if uintptr(*key) != ukey && err == nil {
1432  			err = errorspkg.New("GetQueuedCompletionStatus returned key overflow")
1433  		}
1434  	}
1435  	return err
1436  }
1437  
1438  // Deprecated: PostQueuedCompletionStatus has the wrong function signature. Use x/sys/windows.PostQueuedCompletionStatus.
1439  func PostQueuedCompletionStatus(cphandle Handle, qty uint32, key uint32, overlapped *Overlapped) error {
1440  	return postQueuedCompletionStatus(cphandle, qty, uintptr(key), overlapped)
1441  }
1442  
1443  // newProcThreadAttributeList allocates a new [procThreadAttributeListContainer], with the requested maximum number of attributes.
1444  func newProcThreadAttributeList(maxAttrCount uint32) (*procThreadAttributeListContainer, error) {
1445  	var size uintptr
1446  	err := initializeProcThreadAttributeList(nil, maxAttrCount, 0, &size)
1447  	if err != ERROR_INSUFFICIENT_BUFFER {
1448  		if err == nil {
1449  			return nil, errorspkg.New("unable to query buffer size from InitializeProcThreadAttributeList")
1450  		}
1451  		return nil, err
1452  	}
1453  	const LMEM_FIXED = 0
1454  	alloc, err := localAlloc(LMEM_FIXED, uint32(size))
1455  	if err != nil {
1456  		return nil, err
1457  	}
1458  	// size is guaranteed to be ≥1 by InitializeProcThreadAttributeList.
1459  	al := &procThreadAttributeListContainer{data: (*_PROC_THREAD_ATTRIBUTE_LIST)(unsafe.Pointer(alloc))}
1460  	err = initializeProcThreadAttributeList(al.data, maxAttrCount, 0, &size)
1461  	if err != nil {
1462  		return nil, err
1463  	}
1464  	al.pointers = make([]unsafe.Pointer, 0, maxAttrCount)
1465  	return al, err
1466  }
1467  
1468  // Update modifies the ProcThreadAttributeList using UpdateProcThreadAttribute.
1469  func (al *procThreadAttributeListContainer) update(attribute uintptr, value unsafe.Pointer, size uintptr) error {
1470  	al.pointers = append(al.pointers, value)
1471  	return updateProcThreadAttribute(al.data, 0, attribute, value, size, nil, nil)
1472  }
1473  
1474  // Delete frees ProcThreadAttributeList's resources.
1475  func (al *procThreadAttributeListContainer) delete() {
1476  	deleteProcThreadAttributeList(al.data)
1477  	LocalFree(Handle(unsafe.Pointer(al.data)))
1478  	al.data = nil
1479  	al.pointers = nil
1480  }
1481  
1482  // List returns the actual ProcThreadAttributeList to be passed to StartupInfoEx.
1483  func (al *procThreadAttributeListContainer) list() *_PROC_THREAD_ATTRIBUTE_LIST {
1484  	return al.data
1485  }
1486  
1487  // RegEnumKeyEx enumerates the subkeys of an open registry key.
1488  // Each call retrieves information about one subkey. name is
1489  // a buffer that should be large enough to hold the name of the
1490  // subkey plus a null terminating character. nameLen is its
1491  // length. On return, nameLen will contain the actual length of the
1492  // subkey.
1493  //
1494  // Should name not be large enough to hold the subkey, this function
1495  // will return ERROR_MORE_DATA, and must be called again with an
1496  // appropriately sized buffer.
1497  //
1498  // reserved must be nil. class and classLen behave like name and nameLen
1499  // but for the class of the subkey, except that they are optional.
1500  // lastWriteTime, if not nil, will be populated with the time the subkey
1501  // was last written.
1502  //
1503  // The caller must enumerate all subkeys in order. That is
1504  // RegEnumKeyEx must be called with index starting at 0, incrementing
1505  // the index until the function returns ERROR_NO_MORE_ITEMS, or with
1506  // the index of the last subkey (obtainable from RegQueryInfoKey),
1507  // decrementing until index 0 is enumerated.
1508  //
1509  // Successive calls to this API must happen on the same OS thread,
1510  // so call [runtime.LockOSThread] before calling this function.
1511  func RegEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno error) {
1512  	return regEnumKeyEx(key, index, name, nameLen, reserved, class, classLen, lastWriteTime)
1513  }
1514  
1515  func GetStartupInfo(startupInfo *StartupInfo) error {
1516  	getStartupInfo(startupInfo)
1517  	return nil
1518  }
1519  
1520  func CreateFile(name *uint16, access uint32, mode uint32, sa *SecurityAttributes, createmode uint32, attrs uint32, templatefile int32) (handle Handle, err error) {
1521  	handle, err = createFile(name, access, mode, sa, createmode, attrs, templatefile)
1522  	if handle != InvalidHandle {
1523  		// CreateFileW can return ERROR_ALREADY_EXISTS with a valid handle.
1524  		// We only want to return an error if the handle is invalid.
1525  		err = nil
1526  	}
1527  	return handle, err
1528  }
1529