Source file src/syscall/syscall_windows.go

     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/bytealg"
    12  	"internal/itoa"
    13  	"internal/oserror"
    14  	"internal/race"
    15  	"runtime"
    16  	"sync"
    17  	"unsafe"
    18  )
    19  
    20  type Handle uintptr
    21  
    22  const InvalidHandle = ^Handle(0)
    23  
    24  // StringToUTF16 returns the UTF-16 encoding of the UTF-8 string s,
    25  // with a terminating NUL added. If s contains a NUL byte this
    26  // function panics instead of returning an error.
    27  //
    28  // Deprecated: Use UTF16FromString instead.
    29  func StringToUTF16(s string) []uint16 {
    30  	a, err := UTF16FromString(s)
    31  	if err != nil {
    32  		panic("syscall: string with NUL passed to StringToUTF16")
    33  	}
    34  	return a
    35  }
    36  
    37  // UTF16FromString returns the UTF-16 encoding of the UTF-8 string
    38  // s, with a terminating NUL added. If s contains a NUL byte at any
    39  // location, it returns (nil, EINVAL). Unpaired surrogates
    40  // are encoded using WTF-8.
    41  func UTF16FromString(s string) ([]uint16, error) {
    42  	if bytealg.IndexByteString(s, 0) != -1 {
    43  		return nil, EINVAL
    44  	}
    45  	// Valid UTF-8 characters between 1 and 3 bytes require one uint16.
    46  	// Valid UTF-8 characters of 4 bytes require two uint16.
    47  	// Bytes with invalid UTF-8 encoding require maximum one uint16 per byte.
    48  	// So the number of UTF-8 code units (len(s)) is always greater or
    49  	// equal than the number of UTF-16 code units.
    50  	// Also account for the terminating NUL character.
    51  	buf := make([]uint16, 0, len(s)+1)
    52  	buf = encodeWTF16(s, buf)
    53  	return append(buf, 0), nil
    54  }
    55  
    56  // UTF16ToString returns the UTF-8 encoding of the UTF-16 sequence s,
    57  // with a terminating NUL removed. Unpaired surrogates are decoded
    58  // using WTF-8 instead of UTF-8 encoding.
    59  func UTF16ToString(s []uint16) string {
    60  	maxLen := 0
    61  	for i, v := range s {
    62  		if v == 0 {
    63  			s = s[0:i]
    64  			break
    65  		}
    66  		switch {
    67  		case v <= rune1Max:
    68  			maxLen += 1
    69  		case v <= rune2Max:
    70  			maxLen += 2
    71  		default:
    72  			// r is a non-surrogate that decodes to 3 bytes,
    73  			// or is an unpaired surrogate (also 3 bytes in WTF-8),
    74  			// or is one half of a valid surrogate pair.
    75  			// If it is half of a pair, we will add 3 for the second surrogate
    76  			// (total of 6) and overestimate by 2 bytes for the pair,
    77  			// since the resulting rune only requires 4 bytes.
    78  			maxLen += 3
    79  		}
    80  	}
    81  	buf := decodeWTF16(s, make([]byte, 0, maxLen))
    82  	return unsafe.String(unsafe.SliceData(buf), len(buf))
    83  }
    84  
    85  // utf16PtrToString is like UTF16ToString, but takes *uint16
    86  // as a parameter instead of []uint16.
    87  func utf16PtrToString(p *uint16) string {
    88  	if p == nil {
    89  		return ""
    90  	}
    91  	end := unsafe.Pointer(p)
    92  	n := 0
    93  	for *(*uint16)(end) != 0 {
    94  		end = unsafe.Pointer(uintptr(end) + unsafe.Sizeof(*p))
    95  		n++
    96  	}
    97  	return UTF16ToString(unsafe.Slice(p, n))
    98  }
    99  
   100  // StringToUTF16Ptr returns pointer to the UTF-16 encoding of
   101  // the UTF-8 string s, with a terminating NUL added. If s
   102  // contains a NUL byte this function panics instead of
   103  // returning an error.
   104  //
   105  // Deprecated: Use UTF16PtrFromString instead.
   106  func StringToUTF16Ptr(s string) *uint16 { return &StringToUTF16(s)[0] }
   107  
   108  // UTF16PtrFromString returns pointer to the UTF-16 encoding of
   109  // the UTF-8 string s, with a terminating NUL added. If s
   110  // contains a NUL byte at any location, it returns (nil, EINVAL).
   111  // Unpaired surrogates are encoded using WTF-8.
   112  func UTF16PtrFromString(s string) (*uint16, error) {
   113  	a, err := UTF16FromString(s)
   114  	if err != nil {
   115  		return nil, err
   116  	}
   117  	return &a[0], nil
   118  }
   119  
   120  // Errno is the Windows error number.
   121  //
   122  // Errno values can be tested against error values using errors.Is.
   123  // For example:
   124  //
   125  //	_, _, err := syscall.Syscall(...)
   126  //	if errors.Is(err, fs.ErrNotExist) ...
   127  type Errno uintptr
   128  
   129  func langid(pri, sub uint16) uint32 { return uint32(sub)<<10 | uint32(pri) }
   130  
   131  // FormatMessage is deprecated (msgsrc should be uintptr, not uint32, but can
   132  // not be changed due to the Go 1 compatibility guarantee).
   133  //
   134  // Deprecated: Use FormatMessage from golang.org/x/sys/windows instead.
   135  func FormatMessage(flags uint32, msgsrc uint32, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) {
   136  	return formatMessage(flags, uintptr(msgsrc), msgid, langid, buf, args)
   137  }
   138  
   139  func (e Errno) Error() string {
   140  	// deal with special go errors
   141  	idx := int(e - APPLICATION_ERROR)
   142  	if 0 <= idx && idx < len(errors) {
   143  		return errors[idx]
   144  	}
   145  	// ask windows for the remaining errors
   146  	var flags uint32 = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ARGUMENT_ARRAY | FORMAT_MESSAGE_IGNORE_INSERTS
   147  	b := make([]uint16, 300)
   148  	n, err := formatMessage(flags, 0, uint32(e), langid(LANG_ENGLISH, SUBLANG_ENGLISH_US), b, nil)
   149  	if err != nil {
   150  		n, err = formatMessage(flags, 0, uint32(e), 0, b, nil)
   151  		if err != nil {
   152  			return "winapi error #" + itoa.Itoa(int(e))
   153  		}
   154  	}
   155  	// trim terminating \r and \n
   156  	for ; n > 0 && (b[n-1] == '\n' || b[n-1] == '\r'); n-- {
   157  	}
   158  	return UTF16ToString(b[:n])
   159  }
   160  
   161  const (
   162  	_ERROR_NOT_ENOUGH_MEMORY    = Errno(8)
   163  	_ERROR_NOT_SUPPORTED        = Errno(50)
   164  	_ERROR_BAD_NETPATH          = Errno(53)
   165  	_ERROR_CALL_NOT_IMPLEMENTED = Errno(120)
   166  )
   167  
   168  func (e Errno) Is(target error) bool {
   169  	switch target {
   170  	case oserror.ErrPermission:
   171  		return e == ERROR_ACCESS_DENIED ||
   172  			e == EACCES ||
   173  			e == EPERM
   174  	case oserror.ErrExist:
   175  		return e == ERROR_ALREADY_EXISTS ||
   176  			e == ERROR_DIR_NOT_EMPTY ||
   177  			e == ERROR_FILE_EXISTS ||
   178  			e == EEXIST ||
   179  			e == ENOTEMPTY
   180  	case oserror.ErrNotExist:
   181  		return e == ERROR_FILE_NOT_FOUND ||
   182  			e == _ERROR_BAD_NETPATH ||
   183  			e == ERROR_PATH_NOT_FOUND ||
   184  			e == ENOENT
   185  	case errorspkg.ErrUnsupported:
   186  		return e == _ERROR_NOT_SUPPORTED ||
   187  			e == _ERROR_CALL_NOT_IMPLEMENTED ||
   188  			e == ENOSYS ||
   189  			e == ENOTSUP ||
   190  			e == EOPNOTSUPP ||
   191  			e == EWINDOWS
   192  	}
   193  	return false
   194  }
   195  
   196  func (e Errno) Temporary() bool {
   197  	return e == EINTR || e == EMFILE || e.Timeout()
   198  }
   199  
   200  func (e Errno) Timeout() bool {
   201  	return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
   202  }
   203  
   204  // Implemented in runtime/syscall_windows.go.
   205  func compileCallback(fn any, cleanstack bool) uintptr
   206  
   207  // NewCallback converts a Go function to a function pointer conforming to the stdcall calling convention.
   208  // This is useful when interoperating with Windows code requiring callbacks.
   209  // 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.
   210  // Only a limited number of callbacks may be created in a single Go process, and any memory allocated
   211  // for these callbacks is never released.
   212  // Between NewCallback and NewCallbackCDecl, at least 1024 callbacks can always be created.
   213  func NewCallback(fn any) uintptr {
   214  	return compileCallback(fn, true)
   215  }
   216  
   217  // NewCallbackCDecl converts a Go function to a function pointer conforming to the cdecl calling convention.
   218  // This is useful when interoperating with Windows code requiring callbacks.
   219  // 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.
   220  // Only a limited number of callbacks may be created in a single Go process, and any memory allocated
   221  // for these callbacks is never released.
   222  // Between NewCallback and NewCallbackCDecl, at least 1024 callbacks can always be created.
   223  func NewCallbackCDecl(fn any) uintptr {
   224  	return compileCallback(fn, false)
   225  }
   226  
   227  // windows api calls
   228  
   229  //sys	GetLastError() (lasterr error)
   230  //sys	LoadLibrary(libname string) (handle Handle, err error) = LoadLibraryW
   231  //sys	FreeLibrary(handle Handle) (err error)
   232  //sys	GetProcAddress(module Handle, procname string) (proc uintptr, err error)
   233  //sys	GetVersion() (ver uint32, err error)
   234  //sys	rtlGetNtVersionNumbers(majorVersion *uint32, minorVersion *uint32, buildNumber *uint32) = ntdll.RtlGetNtVersionNumbers
   235  //sys	formatMessage(flags uint32, msgsrc uintptr, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) = FormatMessageW
   236  //sys	ExitProcess(exitcode uint32)
   237  //sys	CreateFile(name *uint16, access uint32, mode uint32, sa *SecurityAttributes, createmode uint32, attrs uint32, templatefile int32) (handle Handle, err error) [failretval==InvalidHandle] = CreateFileW
   238  //sys	readFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error) = ReadFile
   239  //sys	writeFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error) = WriteFile
   240  //sys	SetFilePointer(handle Handle, lowoffset int32, highoffsetptr *int32, whence uint32) (newlowoffset uint32, err error) [failretval==0xffffffff]
   241  //sys	CloseHandle(handle Handle) (err error)
   242  //sys	GetStdHandle(stdhandle int) (handle Handle, err error) [failretval==InvalidHandle]
   243  //sys	findFirstFile1(name *uint16, data *win32finddata1) (handle Handle, err error) [failretval==InvalidHandle] = FindFirstFileW
   244  //sys	findNextFile1(handle Handle, data *win32finddata1) (err error) = FindNextFileW
   245  //sys	FindClose(handle Handle) (err error)
   246  //sys	GetFileInformationByHandle(handle Handle, data *ByHandleFileInformation) (err error)
   247  //sys	GetCurrentDirectory(buflen uint32, buf *uint16) (n uint32, err error) = GetCurrentDirectoryW
   248  //sys	SetCurrentDirectory(path *uint16) (err error) = SetCurrentDirectoryW
   249  //sys	CreateDirectory(path *uint16, sa *SecurityAttributes) (err error) = CreateDirectoryW
   250  //sys	RemoveDirectory(path *uint16) (err error) = RemoveDirectoryW
   251  //sys	DeleteFile(path *uint16) (err error) = DeleteFileW
   252  //sys	MoveFile(from *uint16, to *uint16) (err error) = MoveFileW
   253  //sys	GetComputerName(buf *uint16, n *uint32) (err error) = GetComputerNameW
   254  //sys	SetEndOfFile(handle Handle) (err error)
   255  //sys	GetSystemTimeAsFileTime(time *Filetime)
   256  //sys	GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, err error) [failretval==0xffffffff]
   257  //sys	createIoCompletionPort(filehandle Handle, cphandle Handle, key uintptr, threadcnt uint32) (handle Handle, err error) = CreateIoCompletionPort
   258  //sys	getQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uintptr, overlapped **Overlapped, timeout uint32) (err error) = GetQueuedCompletionStatus
   259  //sys	postQueuedCompletionStatus(cphandle Handle, qty uint32, key uintptr, overlapped *Overlapped) (err error) = PostQueuedCompletionStatus
   260  //sys	CancelIo(s Handle) (err error)
   261  //sys	CancelIoEx(s Handle, o *Overlapped) (err error)
   262  //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
   263  //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
   264  //sys	OpenProcess(da uint32, inheritHandle bool, pid uint32) (handle Handle, err error)
   265  //sys	TerminateProcess(handle Handle, exitcode uint32) (err error)
   266  //sys	GetExitCodeProcess(handle Handle, exitcode *uint32) (err error)
   267  //sys	GetStartupInfo(startupInfo *StartupInfo) (err error) = GetStartupInfoW
   268  //sys	GetCurrentProcess() (pseudoHandle Handle, err error)
   269  //sys	GetProcessTimes(handle Handle, creationTime *Filetime, exitTime *Filetime, kernelTime *Filetime, userTime *Filetime) (err error)
   270  //sys	DuplicateHandle(hSourceProcessHandle Handle, hSourceHandle Handle, hTargetProcessHandle Handle, lpTargetHandle *Handle, dwDesiredAccess uint32, bInheritHandle bool, dwOptions uint32) (err error)
   271  //sys	WaitForSingleObject(handle Handle, waitMilliseconds uint32) (event uint32, err error) [failretval==0xffffffff]
   272  //sys	GetTempPath(buflen uint32, buf *uint16) (n uint32, err error) = GetTempPathW
   273  //sys	CreatePipe(readhandle *Handle, writehandle *Handle, sa *SecurityAttributes, size uint32) (err error)
   274  //sys	GetFileType(filehandle Handle) (n uint32, err error)
   275  //sys	CryptAcquireContext(provhandle *Handle, container *uint16, provider *uint16, provtype uint32, flags uint32) (err error) = advapi32.CryptAcquireContextW
   276  //sys	CryptReleaseContext(provhandle Handle, flags uint32) (err error) = advapi32.CryptReleaseContext
   277  //sys	CryptGenRandom(provhandle Handle, buflen uint32, buf *byte) (err error) = advapi32.CryptGenRandom
   278  //sys	GetEnvironmentStrings() (envs *uint16, err error) [failretval==nil] = kernel32.GetEnvironmentStringsW
   279  //sys	FreeEnvironmentStrings(envs *uint16) (err error) = kernel32.FreeEnvironmentStringsW
   280  //sys	GetEnvironmentVariable(name *uint16, buffer *uint16, size uint32) (n uint32, err error) = kernel32.GetEnvironmentVariableW
   281  //sys	SetEnvironmentVariable(name *uint16, value *uint16) (err error) = kernel32.SetEnvironmentVariableW
   282  //sys	SetFileTime(handle Handle, ctime *Filetime, atime *Filetime, wtime *Filetime) (err error)
   283  //sys	GetFileAttributes(name *uint16) (attrs uint32, err error) [failretval==INVALID_FILE_ATTRIBUTES] = kernel32.GetFileAttributesW
   284  //sys	SetFileAttributes(name *uint16, attrs uint32) (err error) = kernel32.SetFileAttributesW
   285  //sys	GetFileAttributesEx(name *uint16, level uint32, info *byte) (err error) = kernel32.GetFileAttributesExW
   286  //sys	GetCommandLine() (cmd *uint16) = kernel32.GetCommandLineW
   287  //sys	CommandLineToArgv(cmd *uint16, argc *int32) (argv *[8192]*[8192]uint16, err error) [failretval==nil] = shell32.CommandLineToArgvW
   288  //sys	LocalFree(hmem Handle) (handle Handle, err error) [failretval!=0]
   289  //sys	SetHandleInformation(handle Handle, mask uint32, flags uint32) (err error)
   290  //sys	FlushFileBuffers(handle Handle) (err error)
   291  //sys	GetFullPathName(path *uint16, buflen uint32, buf *uint16, fname **uint16) (n uint32, err error) = kernel32.GetFullPathNameW
   292  //sys	GetLongPathName(path *uint16, buf *uint16, buflen uint32) (n uint32, err error) = kernel32.GetLongPathNameW
   293  //sys	GetShortPathName(longpath *uint16, shortpath *uint16, buflen uint32) (n uint32, err error) = kernel32.GetShortPathNameW
   294  //sys	CreateFileMapping(fhandle Handle, sa *SecurityAttributes, prot uint32, maxSizeHigh uint32, maxSizeLow uint32, name *uint16) (handle Handle, err error) = kernel32.CreateFileMappingW
   295  //sys	MapViewOfFile(handle Handle, access uint32, offsetHigh uint32, offsetLow uint32, length uintptr) (addr uintptr, err error)
   296  //sys	UnmapViewOfFile(addr uintptr) (err error)
   297  //sys	FlushViewOfFile(addr uintptr, length uintptr) (err error)
   298  //sys	VirtualLock(addr uintptr, length uintptr) (err error)
   299  //sys	VirtualUnlock(addr uintptr, length uintptr) (err error)
   300  //sys	TransmitFile(s Handle, handle Handle, bytesToWrite uint32, bytsPerSend uint32, overlapped *Overlapped, transmitFileBuf *TransmitFileBuffers, flags uint32) (err error) = mswsock.TransmitFile
   301  //sys	ReadDirectoryChanges(handle Handle, buf *byte, buflen uint32, watchSubTree bool, mask uint32, retlen *uint32, overlapped *Overlapped, completionRoutine uintptr) (err error) = kernel32.ReadDirectoryChangesW
   302  //sys	CertOpenSystemStore(hprov Handle, name *uint16) (store Handle, err error) = crypt32.CertOpenSystemStoreW
   303  //sys   CertOpenStore(storeProvider uintptr, msgAndCertEncodingType uint32, cryptProv uintptr, flags uint32, para uintptr) (handle Handle, err error) = crypt32.CertOpenStore
   304  //sys	CertEnumCertificatesInStore(store Handle, prevContext *CertContext) (context *CertContext, err error) [failretval==nil] = crypt32.CertEnumCertificatesInStore
   305  //sys   CertAddCertificateContextToStore(store Handle, certContext *CertContext, addDisposition uint32, storeContext **CertContext) (err error) = crypt32.CertAddCertificateContextToStore
   306  //sys	CertCloseStore(store Handle, flags uint32) (err error) = crypt32.CertCloseStore
   307  //sys   CertGetCertificateChain(engine Handle, leaf *CertContext, time *Filetime, additionalStore Handle, para *CertChainPara, flags uint32, reserved uintptr, chainCtx **CertChainContext) (err error) = crypt32.CertGetCertificateChain
   308  //sys   CertFreeCertificateChain(ctx *CertChainContext) = crypt32.CertFreeCertificateChain
   309  //sys   CertCreateCertificateContext(certEncodingType uint32, certEncoded *byte, encodedLen uint32) (context *CertContext, err error) [failretval==nil] = crypt32.CertCreateCertificateContext
   310  //sys   CertFreeCertificateContext(ctx *CertContext) (err error) = crypt32.CertFreeCertificateContext
   311  //sys   CertVerifyCertificateChainPolicy(policyOID uintptr, chain *CertChainContext, para *CertChainPolicyPara, status *CertChainPolicyStatus) (err error) = crypt32.CertVerifyCertificateChainPolicy
   312  //sys	RegOpenKeyEx(key Handle, subkey *uint16, options uint32, desiredAccess uint32, result *Handle) (regerrno error) = advapi32.RegOpenKeyExW
   313  //sys	RegCloseKey(key Handle) (regerrno error) = advapi32.RegCloseKey
   314  //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
   315  //sys	regEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno error) = advapi32.RegEnumKeyExW
   316  //sys	RegQueryValueEx(key Handle, name *uint16, reserved *uint32, valtype *uint32, buf *byte, buflen *uint32) (regerrno error) = advapi32.RegQueryValueExW
   317  //sys	getCurrentProcessId() (pid uint32) = kernel32.GetCurrentProcessId
   318  //sys	GetConsoleMode(console Handle, mode *uint32) (err error) = kernel32.GetConsoleMode
   319  //sys	WriteConsole(console Handle, buf *uint16, towrite uint32, written *uint32, reserved *byte) (err error) = kernel32.WriteConsoleW
   320  //sys	ReadConsole(console Handle, buf *uint16, toread uint32, read *uint32, inputControl *byte) (err error) = kernel32.ReadConsoleW
   321  //sys	CreateToolhelp32Snapshot(flags uint32, processId uint32) (handle Handle, err error) [failretval==InvalidHandle] = kernel32.CreateToolhelp32Snapshot
   322  //sys	Process32First(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32FirstW
   323  //sys	Process32Next(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32NextW
   324  //sys	DeviceIoControl(handle Handle, ioControlCode uint32, inBuffer *byte, inBufferSize uint32, outBuffer *byte, outBufferSize uint32, bytesReturned *uint32, overlapped *Overlapped) (err error)
   325  // This function returns 1 byte BOOLEAN rather than the 4 byte BOOL.
   326  //sys	CreateSymbolicLink(symlinkfilename *uint16, targetfilename *uint16, flags uint32) (err error) [failretval&0xff==0] = CreateSymbolicLinkW
   327  //sys	CreateHardLink(filename *uint16, existingfilename *uint16, reserved uintptr) (err error) [failretval&0xff==0] = CreateHardLinkW
   328  //sys	initializeProcThreadAttributeList(attrlist *_PROC_THREAD_ATTRIBUTE_LIST, attrcount uint32, flags uint32, size *uintptr) (err error) = InitializeProcThreadAttributeList
   329  //sys	deleteProcThreadAttributeList(attrlist *_PROC_THREAD_ATTRIBUTE_LIST) = DeleteProcThreadAttributeList
   330  //sys	updateProcThreadAttribute(attrlist *_PROC_THREAD_ATTRIBUTE_LIST, flags uint32, attr uintptr, value unsafe.Pointer, size uintptr, prevvalue unsafe.Pointer, returnedsize *uintptr) (err error) = UpdateProcThreadAttribute
   331  //sys	getFinalPathNameByHandle(file Handle, filePath *uint16, filePathSize uint32, flags uint32) (n uint32, err error) [n == 0 || n >= filePathSize] = kernel32.GetFinalPathNameByHandleW
   332  
   333  // syscall interface implementation for other packages
   334  
   335  func makeInheritSa() *SecurityAttributes {
   336  	var sa SecurityAttributes
   337  	sa.Length = uint32(unsafe.Sizeof(sa))
   338  	sa.InheritHandle = 1
   339  	return &sa
   340  }
   341  
   342  func Open(path string, mode int, perm uint32) (fd Handle, err error) {
   343  	if len(path) == 0 {
   344  		return InvalidHandle, ERROR_FILE_NOT_FOUND
   345  	}
   346  	pathp, err := UTF16PtrFromString(path)
   347  	if err != nil {
   348  		return InvalidHandle, err
   349  	}
   350  	var access uint32
   351  	switch mode & (O_RDONLY | O_WRONLY | O_RDWR) {
   352  	case O_RDONLY:
   353  		access = GENERIC_READ
   354  	case O_WRONLY:
   355  		access = GENERIC_WRITE
   356  	case O_RDWR:
   357  		access = GENERIC_READ | GENERIC_WRITE
   358  	}
   359  	if mode&O_CREAT != 0 {
   360  		access |= GENERIC_WRITE
   361  	}
   362  	if mode&O_APPEND != 0 {
   363  		access &^= GENERIC_WRITE
   364  		access |= FILE_APPEND_DATA
   365  	}
   366  	sharemode := uint32(FILE_SHARE_READ | FILE_SHARE_WRITE)
   367  	var sa *SecurityAttributes
   368  	if mode&O_CLOEXEC == 0 {
   369  		sa = makeInheritSa()
   370  	}
   371  	var createmode uint32
   372  	switch {
   373  	case mode&(O_CREAT|O_EXCL) == (O_CREAT | O_EXCL):
   374  		createmode = CREATE_NEW
   375  	case mode&(O_CREAT|O_TRUNC) == (O_CREAT | O_TRUNC):
   376  		createmode = CREATE_ALWAYS
   377  	case mode&O_CREAT == O_CREAT:
   378  		createmode = OPEN_ALWAYS
   379  	case mode&O_TRUNC == O_TRUNC:
   380  		createmode = TRUNCATE_EXISTING
   381  	default:
   382  		createmode = OPEN_EXISTING
   383  	}
   384  	var attrs uint32 = FILE_ATTRIBUTE_NORMAL
   385  	if perm&S_IWRITE == 0 {
   386  		attrs = FILE_ATTRIBUTE_READONLY
   387  		if createmode == CREATE_ALWAYS {
   388  			// We have been asked to create a read-only file.
   389  			// If the file already exists, the semantics of
   390  			// the Unix open system call is to preserve the
   391  			// existing permissions. If we pass CREATE_ALWAYS
   392  			// and FILE_ATTRIBUTE_READONLY to CreateFile,
   393  			// and the file already exists, CreateFile will
   394  			// change the file permissions.
   395  			// Avoid that to preserve the Unix semantics.
   396  			h, e := CreateFile(pathp, access, sharemode, sa, TRUNCATE_EXISTING, FILE_ATTRIBUTE_NORMAL, 0)
   397  			switch e {
   398  			case ERROR_FILE_NOT_FOUND, _ERROR_BAD_NETPATH, ERROR_PATH_NOT_FOUND:
   399  				// File does not exist. These are the same
   400  				// errors as Errno.Is checks for ErrNotExist.
   401  				// Carry on to create the file.
   402  			default:
   403  				// Success or some different error.
   404  				return h, e
   405  			}
   406  		}
   407  	}
   408  	if createmode == OPEN_EXISTING && access == GENERIC_READ {
   409  		// Necessary for opening directory handles.
   410  		attrs |= FILE_FLAG_BACKUP_SEMANTICS
   411  	}
   412  	return CreateFile(pathp, access, sharemode, sa, createmode, attrs, 0)
   413  }
   414  
   415  func Read(fd Handle, p []byte) (n int, err error) {
   416  	var done uint32
   417  	e := ReadFile(fd, p, &done, nil)
   418  	if e != nil {
   419  		if e == ERROR_BROKEN_PIPE {
   420  			// NOTE(brainman): work around ERROR_BROKEN_PIPE is returned on reading EOF from stdin
   421  			return 0, nil
   422  		}
   423  		return 0, e
   424  	}
   425  	return int(done), nil
   426  }
   427  
   428  func Write(fd Handle, p []byte) (n int, err error) {
   429  	var done uint32
   430  	e := WriteFile(fd, p, &done, nil)
   431  	if e != nil {
   432  		return 0, e
   433  	}
   434  	return int(done), nil
   435  }
   436  
   437  func ReadFile(fd Handle, p []byte, done *uint32, overlapped *Overlapped) error {
   438  	err := readFile(fd, p, done, overlapped)
   439  	if race.Enabled {
   440  		if *done > 0 {
   441  			race.WriteRange(unsafe.Pointer(&p[0]), int(*done))
   442  		}
   443  		race.Acquire(unsafe.Pointer(&ioSync))
   444  	}
   445  	if msanenabled && *done > 0 {
   446  		msanWrite(unsafe.Pointer(&p[0]), int(*done))
   447  	}
   448  	if asanenabled && *done > 0 {
   449  		asanWrite(unsafe.Pointer(&p[0]), int(*done))
   450  	}
   451  	return err
   452  }
   453  
   454  func WriteFile(fd Handle, p []byte, done *uint32, overlapped *Overlapped) error {
   455  	if race.Enabled {
   456  		race.ReleaseMerge(unsafe.Pointer(&ioSync))
   457  	}
   458  	err := writeFile(fd, p, done, overlapped)
   459  	if race.Enabled && *done > 0 {
   460  		race.ReadRange(unsafe.Pointer(&p[0]), int(*done))
   461  	}
   462  	if msanenabled && *done > 0 {
   463  		msanRead(unsafe.Pointer(&p[0]), int(*done))
   464  	}
   465  	if asanenabled && *done > 0 {
   466  		asanRead(unsafe.Pointer(&p[0]), int(*done))
   467  	}
   468  	return err
   469  }
   470  
   471  var ioSync int64
   472  
   473  var procSetFilePointerEx = modkernel32.NewProc("SetFilePointerEx")
   474  
   475  const ptrSize = unsafe.Sizeof(uintptr(0))
   476  
   477  // setFilePointerEx calls SetFilePointerEx.
   478  // See https://msdn.microsoft.com/en-us/library/windows/desktop/aa365542(v=vs.85).aspx
   479  func setFilePointerEx(handle Handle, distToMove int64, newFilePointer *int64, whence uint32) error {
   480  	var e1 Errno
   481  	if unsafe.Sizeof(uintptr(0)) == 8 {
   482  		_, _, e1 = Syscall6(procSetFilePointerEx.Addr(), 4, uintptr(handle), uintptr(distToMove), uintptr(unsafe.Pointer(newFilePointer)), uintptr(whence), 0, 0)
   483  	} else {
   484  		// Different 32-bit systems disgaree about whether distToMove starts 8-byte aligned.
   485  		switch runtime.GOARCH {
   486  		default:
   487  			panic("unsupported 32-bit architecture")
   488  		case "386":
   489  			// distToMove is a LARGE_INTEGER, which is 64 bits.
   490  			_, _, e1 = Syscall6(procSetFilePointerEx.Addr(), 5, uintptr(handle), uintptr(distToMove), uintptr(distToMove>>32), uintptr(unsafe.Pointer(newFilePointer)), uintptr(whence), 0)
   491  		case "arm":
   492  			// distToMove must be 8-byte aligned per ARM calling convention
   493  			// https://docs.microsoft.com/en-us/cpp/build/overview-of-arm-abi-conventions#stage-c-assignment-of-arguments-to-registers-and-stack
   494  			_, _, e1 = Syscall6(procSetFilePointerEx.Addr(), 6, uintptr(handle), 0, uintptr(distToMove), uintptr(distToMove>>32), uintptr(unsafe.Pointer(newFilePointer)), uintptr(whence))
   495  		}
   496  	}
   497  	if e1 != 0 {
   498  		return errnoErr(e1)
   499  	}
   500  	return nil
   501  }
   502  
   503  func Seek(fd Handle, offset int64, whence int) (newoffset int64, err error) {
   504  	var w uint32
   505  	switch whence {
   506  	case 0:
   507  		w = FILE_BEGIN
   508  	case 1:
   509  		w = FILE_CURRENT
   510  	case 2:
   511  		w = FILE_END
   512  	}
   513  	err = setFilePointerEx(fd, offset, &newoffset, w)
   514  	return
   515  }
   516  
   517  func Close(fd Handle) (err error) {
   518  	return CloseHandle(fd)
   519  }
   520  
   521  var (
   522  	Stdin  = getStdHandle(STD_INPUT_HANDLE)
   523  	Stdout = getStdHandle(STD_OUTPUT_HANDLE)
   524  	Stderr = getStdHandle(STD_ERROR_HANDLE)
   525  )
   526  
   527  func getStdHandle(h int) (fd Handle) {
   528  	r, _ := GetStdHandle(h)
   529  	return r
   530  }
   531  
   532  const ImplementsGetwd = true
   533  
   534  func Getwd() (wd string, err error) {
   535  	b := make([]uint16, 300)
   536  	// The path of the current directory may not fit in the initial 300-word
   537  	// buffer when long path support is enabled. The current directory may also
   538  	// change between subsequent calls of GetCurrentDirectory. As a result, we
   539  	// need to retry the call in a loop until the current directory fits, each
   540  	// time with a bigger buffer.
   541  	for {
   542  		n, e := GetCurrentDirectory(uint32(len(b)), &b[0])
   543  		if e != nil {
   544  			return "", e
   545  		}
   546  		if int(n) <= len(b) {
   547  			return UTF16ToString(b[:n]), nil
   548  		}
   549  		b = make([]uint16, n)
   550  	}
   551  }
   552  
   553  func Chdir(path string) (err error) {
   554  	pathp, err := UTF16PtrFromString(path)
   555  	if err != nil {
   556  		return err
   557  	}
   558  	return SetCurrentDirectory(pathp)
   559  }
   560  
   561  func Mkdir(path string, mode uint32) (err error) {
   562  	pathp, err := UTF16PtrFromString(path)
   563  	if err != nil {
   564  		return err
   565  	}
   566  	return CreateDirectory(pathp, nil)
   567  }
   568  
   569  func Rmdir(path string) (err error) {
   570  	pathp, err := UTF16PtrFromString(path)
   571  	if err != nil {
   572  		return err
   573  	}
   574  	return RemoveDirectory(pathp)
   575  }
   576  
   577  func Unlink(path string) (err error) {
   578  	pathp, err := UTF16PtrFromString(path)
   579  	if err != nil {
   580  		return err
   581  	}
   582  	return DeleteFile(pathp)
   583  }
   584  
   585  func Rename(oldpath, newpath string) (err error) {
   586  	from, err := UTF16PtrFromString(oldpath)
   587  	if err != nil {
   588  		return err
   589  	}
   590  	to, err := UTF16PtrFromString(newpath)
   591  	if err != nil {
   592  		return err
   593  	}
   594  	return MoveFile(from, to)
   595  }
   596  
   597  func ComputerName() (name string, err error) {
   598  	var n uint32 = MAX_COMPUTERNAME_LENGTH + 1
   599  	b := make([]uint16, n)
   600  	e := GetComputerName(&b[0], &n)
   601  	if e != nil {
   602  		return "", e
   603  	}
   604  	return UTF16ToString(b[:n]), nil
   605  }
   606  
   607  func Ftruncate(fd Handle, length int64) (err error) {
   608  	curoffset, e := Seek(fd, 0, 1)
   609  	if e != nil {
   610  		return e
   611  	}
   612  	defer Seek(fd, curoffset, 0)
   613  	_, e = Seek(fd, length, 0)
   614  	if e != nil {
   615  		return e
   616  	}
   617  	e = SetEndOfFile(fd)
   618  	if e != nil {
   619  		return e
   620  	}
   621  	return nil
   622  }
   623  
   624  func Gettimeofday(tv *Timeval) (err error) {
   625  	var ft Filetime
   626  	GetSystemTimeAsFileTime(&ft)
   627  	*tv = NsecToTimeval(ft.Nanoseconds())
   628  	return nil
   629  }
   630  
   631  func Pipe(p []Handle) (err error) {
   632  	if len(p) != 2 {
   633  		return EINVAL
   634  	}
   635  	var r, w Handle
   636  	e := CreatePipe(&r, &w, makeInheritSa(), 0)
   637  	if e != nil {
   638  		return e
   639  	}
   640  	p[0] = r
   641  	p[1] = w
   642  	return nil
   643  }
   644  
   645  func Utimes(path string, tv []Timeval) (err error) {
   646  	if len(tv) != 2 {
   647  		return EINVAL
   648  	}
   649  	pathp, e := UTF16PtrFromString(path)
   650  	if e != nil {
   651  		return e
   652  	}
   653  	h, e := CreateFile(pathp,
   654  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
   655  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
   656  	if e != nil {
   657  		return e
   658  	}
   659  	defer Close(h)
   660  	a := Filetime{}
   661  	w := Filetime{}
   662  	if tv[0].Nanoseconds() != 0 {
   663  		a = NsecToFiletime(tv[0].Nanoseconds())
   664  	}
   665  	if tv[0].Nanoseconds() != 0 {
   666  		w = NsecToFiletime(tv[1].Nanoseconds())
   667  	}
   668  	return SetFileTime(h, nil, &a, &w)
   669  }
   670  
   671  // This matches the value in os/file_windows.go.
   672  const _UTIME_OMIT = -1
   673  
   674  func UtimesNano(path string, ts []Timespec) (err error) {
   675  	if len(ts) != 2 {
   676  		return EINVAL
   677  	}
   678  	pathp, e := UTF16PtrFromString(path)
   679  	if e != nil {
   680  		return e
   681  	}
   682  	h, e := CreateFile(pathp,
   683  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
   684  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
   685  	if e != nil {
   686  		return e
   687  	}
   688  	defer Close(h)
   689  	a := Filetime{}
   690  	w := Filetime{}
   691  	if ts[0].Nsec != _UTIME_OMIT {
   692  		a = NsecToFiletime(TimespecToNsec(ts[0]))
   693  	}
   694  	if ts[1].Nsec != _UTIME_OMIT {
   695  		w = NsecToFiletime(TimespecToNsec(ts[1]))
   696  	}
   697  	return SetFileTime(h, nil, &a, &w)
   698  }
   699  
   700  func Fsync(fd Handle) (err error) {
   701  	return FlushFileBuffers(fd)
   702  }
   703  
   704  func Chmod(path string, mode uint32) (err error) {
   705  	p, e := UTF16PtrFromString(path)
   706  	if e != nil {
   707  		return e
   708  	}
   709  	attrs, e := GetFileAttributes(p)
   710  	if e != nil {
   711  		return e
   712  	}
   713  	if mode&S_IWRITE != 0 {
   714  		attrs &^= FILE_ATTRIBUTE_READONLY
   715  	} else {
   716  		attrs |= FILE_ATTRIBUTE_READONLY
   717  	}
   718  	return SetFileAttributes(p, attrs)
   719  }
   720  
   721  func LoadCancelIoEx() error {
   722  	return procCancelIoEx.Find()
   723  }
   724  
   725  func LoadSetFileCompletionNotificationModes() error {
   726  	return procSetFileCompletionNotificationModes.Find()
   727  }
   728  
   729  // net api calls
   730  
   731  const socket_error = uintptr(^uint32(0))
   732  
   733  //sys	WSAStartup(verreq uint32, data *WSAData) (sockerr error) = ws2_32.WSAStartup
   734  //sys	WSACleanup() (err error) [failretval==socket_error] = ws2_32.WSACleanup
   735  //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
   736  //sys	socket(af int32, typ int32, protocol int32) (handle Handle, err error) [failretval==InvalidHandle] = ws2_32.socket
   737  //sys	Setsockopt(s Handle, level int32, optname int32, optval *byte, optlen int32) (err error) [failretval==socket_error] = ws2_32.setsockopt
   738  //sys	Getsockopt(s Handle, level int32, optname int32, optval *byte, optlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockopt
   739  //sys	bind(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.bind
   740  //sys	connect(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.connect
   741  //sys	getsockname(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockname
   742  //sys	getpeername(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getpeername
   743  //sys	listen(s Handle, backlog int32) (err error) [failretval==socket_error] = ws2_32.listen
   744  //sys	shutdown(s Handle, how int32) (err error) [failretval==socket_error] = ws2_32.shutdown
   745  //sys	Closesocket(s Handle) (err error) [failretval==socket_error] = ws2_32.closesocket
   746  //sys	AcceptEx(ls Handle, as Handle, buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, recvd *uint32, overlapped *Overlapped) (err error) = mswsock.AcceptEx
   747  //sys	GetAcceptExSockaddrs(buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, lrsa **RawSockaddrAny, lrsalen *int32, rrsa **RawSockaddrAny, rrsalen *int32) = mswsock.GetAcceptExSockaddrs
   748  //sys	WSARecv(s Handle, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSARecv
   749  //sys	WSASend(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSASend
   750  //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
   751  //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
   752  //sys	GetHostByName(name string) (h *Hostent, err error) [failretval==nil] = ws2_32.gethostbyname
   753  //sys	GetServByName(name string, proto string) (s *Servent, err error) [failretval==nil] = ws2_32.getservbyname
   754  //sys	Ntohs(netshort uint16) (u uint16) = ws2_32.ntohs
   755  //sys	GetProtoByName(name string) (p *Protoent, err error) [failretval==nil] = ws2_32.getprotobyname
   756  //sys	DnsQuery(name string, qtype uint16, options uint32, extra *byte, qrs **DNSRecord, pr *byte) (status error) = dnsapi.DnsQuery_W
   757  //sys	DnsRecordListFree(rl *DNSRecord, freetype uint32) = dnsapi.DnsRecordListFree
   758  //sys	DnsNameCompare(name1 *uint16, name2 *uint16) (same bool) = dnsapi.DnsNameCompare_W
   759  //sys	GetAddrInfoW(nodename *uint16, servicename *uint16, hints *AddrinfoW, result **AddrinfoW) (sockerr error) = ws2_32.GetAddrInfoW
   760  //sys	FreeAddrInfoW(addrinfo *AddrinfoW) = ws2_32.FreeAddrInfoW
   761  //sys	GetIfEntry(pIfRow *MibIfRow) (errcode error) = iphlpapi.GetIfEntry
   762  //sys	GetAdaptersInfo(ai *IpAdapterInfo, ol *uint32) (errcode error) = iphlpapi.GetAdaptersInfo
   763  //sys	SetFileCompletionNotificationModes(handle Handle, flags uint8) (err error) = kernel32.SetFileCompletionNotificationModes
   764  //sys	WSAEnumProtocols(protocols *int32, protocolBuffer *WSAProtocolInfo, bufferLength *uint32) (n int32, err error) [failretval==-1] = ws2_32.WSAEnumProtocolsW
   765  
   766  // For testing: clients can set this flag to force
   767  // creation of IPv6 sockets to return EAFNOSUPPORT.
   768  var SocketDisableIPv6 bool
   769  
   770  type RawSockaddrInet4 struct {
   771  	Family uint16
   772  	Port   uint16
   773  	Addr   [4]byte /* in_addr */
   774  	Zero   [8]uint8
   775  }
   776  
   777  type RawSockaddrInet6 struct {
   778  	Family   uint16
   779  	Port     uint16
   780  	Flowinfo uint32
   781  	Addr     [16]byte /* in6_addr */
   782  	Scope_id uint32
   783  }
   784  
   785  type RawSockaddr struct {
   786  	Family uint16
   787  	Data   [14]int8
   788  }
   789  
   790  type RawSockaddrAny struct {
   791  	Addr RawSockaddr
   792  	Pad  [100]int8
   793  }
   794  
   795  type Sockaddr interface {
   796  	sockaddr() (ptr unsafe.Pointer, len int32, err error) // lowercase; only we can define Sockaddrs
   797  }
   798  
   799  type SockaddrInet4 struct {
   800  	Port int
   801  	Addr [4]byte
   802  	raw  RawSockaddrInet4
   803  }
   804  
   805  func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, int32, error) {
   806  	if sa.Port < 0 || sa.Port > 0xFFFF {
   807  		return nil, 0, EINVAL
   808  	}
   809  	sa.raw.Family = AF_INET
   810  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   811  	p[0] = byte(sa.Port >> 8)
   812  	p[1] = byte(sa.Port)
   813  	sa.raw.Addr = sa.Addr
   814  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
   815  }
   816  
   817  type SockaddrInet6 struct {
   818  	Port   int
   819  	ZoneId uint32
   820  	Addr   [16]byte
   821  	raw    RawSockaddrInet6
   822  }
   823  
   824  func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, int32, error) {
   825  	if sa.Port < 0 || sa.Port > 0xFFFF {
   826  		return nil, 0, EINVAL
   827  	}
   828  	sa.raw.Family = AF_INET6
   829  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   830  	p[0] = byte(sa.Port >> 8)
   831  	p[1] = byte(sa.Port)
   832  	sa.raw.Scope_id = sa.ZoneId
   833  	sa.raw.Addr = sa.Addr
   834  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
   835  }
   836  
   837  type RawSockaddrUnix struct {
   838  	Family uint16
   839  	Path   [UNIX_PATH_MAX]int8
   840  }
   841  
   842  type SockaddrUnix struct {
   843  	Name string
   844  	raw  RawSockaddrUnix
   845  }
   846  
   847  func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, int32, error) {
   848  	name := sa.Name
   849  	n := len(name)
   850  	if n > len(sa.raw.Path) {
   851  		return nil, 0, EINVAL
   852  	}
   853  	if n == len(sa.raw.Path) && name[0] != '@' {
   854  		return nil, 0, EINVAL
   855  	}
   856  	sa.raw.Family = AF_UNIX
   857  	for i := 0; i < n; i++ {
   858  		sa.raw.Path[i] = int8(name[i])
   859  	}
   860  	// length is family (uint16), name, NUL.
   861  	sl := int32(2)
   862  	if n > 0 {
   863  		sl += int32(n) + 1
   864  	}
   865  	if sa.raw.Path[0] == '@' {
   866  		sa.raw.Path[0] = 0
   867  		// Don't count trailing NUL for abstract address.
   868  		sl--
   869  	}
   870  
   871  	return unsafe.Pointer(&sa.raw), sl, nil
   872  }
   873  
   874  func (rsa *RawSockaddrAny) Sockaddr() (Sockaddr, error) {
   875  	switch rsa.Addr.Family {
   876  	case AF_UNIX:
   877  		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
   878  		sa := new(SockaddrUnix)
   879  		if pp.Path[0] == 0 {
   880  			// "Abstract" Unix domain socket.
   881  			// Rewrite leading NUL as @ for textual display.
   882  			// (This is the standard convention.)
   883  			// Not friendly to overwrite in place,
   884  			// but the callers below don't care.
   885  			pp.Path[0] = '@'
   886  		}
   887  
   888  		// Assume path ends at NUL.
   889  		// This is not technically the Linux semantics for
   890  		// abstract Unix domain sockets--they are supposed
   891  		// to be uninterpreted fixed-size binary blobs--but
   892  		// everyone uses this convention.
   893  		n := 0
   894  		for n < len(pp.Path) && pp.Path[n] != 0 {
   895  			n++
   896  		}
   897  		sa.Name = string(unsafe.Slice((*byte)(unsafe.Pointer(&pp.Path[0])), n))
   898  		return sa, nil
   899  
   900  	case AF_INET:
   901  		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
   902  		sa := new(SockaddrInet4)
   903  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   904  		sa.Port = int(p[0])<<8 + int(p[1])
   905  		sa.Addr = pp.Addr
   906  		return sa, nil
   907  
   908  	case AF_INET6:
   909  		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
   910  		sa := new(SockaddrInet6)
   911  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   912  		sa.Port = int(p[0])<<8 + int(p[1])
   913  		sa.ZoneId = pp.Scope_id
   914  		sa.Addr = pp.Addr
   915  		return sa, nil
   916  	}
   917  	return nil, EAFNOSUPPORT
   918  }
   919  
   920  func Socket(domain, typ, proto int) (fd Handle, err error) {
   921  	if domain == AF_INET6 && SocketDisableIPv6 {
   922  		return InvalidHandle, EAFNOSUPPORT
   923  	}
   924  	return socket(int32(domain), int32(typ), int32(proto))
   925  }
   926  
   927  func SetsockoptInt(fd Handle, level, opt int, value int) (err error) {
   928  	v := int32(value)
   929  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&v)), int32(unsafe.Sizeof(v)))
   930  }
   931  
   932  func Bind(fd Handle, sa Sockaddr) (err error) {
   933  	ptr, n, err := sa.sockaddr()
   934  	if err != nil {
   935  		return err
   936  	}
   937  	return bind(fd, ptr, n)
   938  }
   939  
   940  func Connect(fd Handle, sa Sockaddr) (err error) {
   941  	ptr, n, err := sa.sockaddr()
   942  	if err != nil {
   943  		return err
   944  	}
   945  	return connect(fd, ptr, n)
   946  }
   947  
   948  func Getsockname(fd Handle) (sa Sockaddr, err error) {
   949  	var rsa RawSockaddrAny
   950  	l := int32(unsafe.Sizeof(rsa))
   951  	if err = getsockname(fd, &rsa, &l); err != nil {
   952  		return
   953  	}
   954  	return rsa.Sockaddr()
   955  }
   956  
   957  func Getpeername(fd Handle) (sa Sockaddr, err error) {
   958  	var rsa RawSockaddrAny
   959  	l := int32(unsafe.Sizeof(rsa))
   960  	if err = getpeername(fd, &rsa, &l); err != nil {
   961  		return
   962  	}
   963  	return rsa.Sockaddr()
   964  }
   965  
   966  func Listen(s Handle, n int) (err error) {
   967  	return listen(s, int32(n))
   968  }
   969  
   970  func Shutdown(fd Handle, how int) (err error) {
   971  	return shutdown(fd, int32(how))
   972  }
   973  
   974  func WSASendto(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to Sockaddr, overlapped *Overlapped, croutine *byte) (err error) {
   975  	var rsa unsafe.Pointer
   976  	var len int32
   977  	if to != nil {
   978  		rsa, len, err = to.sockaddr()
   979  		if err != nil {
   980  			return err
   981  		}
   982  	}
   983  	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)))
   984  	if r1 == socket_error {
   985  		if e1 != 0 {
   986  			err = errnoErr(e1)
   987  		} else {
   988  			err = EINVAL
   989  		}
   990  	}
   991  	return err
   992  }
   993  
   994  func wsaSendtoInet4(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *SockaddrInet4, overlapped *Overlapped, croutine *byte) (err error) {
   995  	rsa, len, err := to.sockaddr()
   996  	if err != nil {
   997  		return err
   998  	}
   999  	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)))
  1000  	if r1 == socket_error {
  1001  		if e1 != 0 {
  1002  			err = errnoErr(e1)
  1003  		} else {
  1004  			err = EINVAL
  1005  		}
  1006  	}
  1007  	return err
  1008  }
  1009  
  1010  func wsaSendtoInet6(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *SockaddrInet6, overlapped *Overlapped, croutine *byte) (err error) {
  1011  	rsa, len, err := to.sockaddr()
  1012  	if err != nil {
  1013  		return err
  1014  	}
  1015  	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)))
  1016  	if r1 == socket_error {
  1017  		if e1 != 0 {
  1018  			err = errnoErr(e1)
  1019  		} else {
  1020  			err = EINVAL
  1021  		}
  1022  	}
  1023  	return err
  1024  }
  1025  
  1026  func LoadGetAddrInfo() error {
  1027  	return procGetAddrInfoW.Find()
  1028  }
  1029  
  1030  var connectExFunc struct {
  1031  	once sync.Once
  1032  	addr uintptr
  1033  	err  error
  1034  }
  1035  
  1036  func LoadConnectEx() error {
  1037  	connectExFunc.once.Do(func() {
  1038  		var s Handle
  1039  		s, connectExFunc.err = Socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)
  1040  		if connectExFunc.err != nil {
  1041  			return
  1042  		}
  1043  		defer CloseHandle(s)
  1044  		var n uint32
  1045  		connectExFunc.err = WSAIoctl(s,
  1046  			SIO_GET_EXTENSION_FUNCTION_POINTER,
  1047  			(*byte)(unsafe.Pointer(&WSAID_CONNECTEX)),
  1048  			uint32(unsafe.Sizeof(WSAID_CONNECTEX)),
  1049  			(*byte)(unsafe.Pointer(&connectExFunc.addr)),
  1050  			uint32(unsafe.Sizeof(connectExFunc.addr)),
  1051  			&n, nil, 0)
  1052  	})
  1053  	return connectExFunc.err
  1054  }
  1055  
  1056  func connectEx(s Handle, name unsafe.Pointer, namelen int32, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) (err error) {
  1057  	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)
  1058  	if r1 == 0 {
  1059  		if e1 != 0 {
  1060  			err = error(e1)
  1061  		} else {
  1062  			err = EINVAL
  1063  		}
  1064  	}
  1065  	return
  1066  }
  1067  
  1068  func ConnectEx(fd Handle, sa Sockaddr, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) error {
  1069  	err := LoadConnectEx()
  1070  	if err != nil {
  1071  		return errorspkg.New("failed to find ConnectEx: " + err.Error())
  1072  	}
  1073  	ptr, n, err := sa.sockaddr()
  1074  	if err != nil {
  1075  		return err
  1076  	}
  1077  	return connectEx(fd, ptr, n, sendBuf, sendDataLen, bytesSent, overlapped)
  1078  }
  1079  
  1080  // Invented structures to support what package os expects.
  1081  type Rusage struct {
  1082  	CreationTime Filetime
  1083  	ExitTime     Filetime
  1084  	KernelTime   Filetime
  1085  	UserTime     Filetime
  1086  }
  1087  
  1088  type WaitStatus struct {
  1089  	ExitCode uint32
  1090  }
  1091  
  1092  func (w WaitStatus) Exited() bool { return true }
  1093  
  1094  func (w WaitStatus) ExitStatus() int { return int(w.ExitCode) }
  1095  
  1096  func (w WaitStatus) Signal() Signal { return -1 }
  1097  
  1098  func (w WaitStatus) CoreDump() bool { return false }
  1099  
  1100  func (w WaitStatus) Stopped() bool { return false }
  1101  
  1102  func (w WaitStatus) Continued() bool { return false }
  1103  
  1104  func (w WaitStatus) StopSignal() Signal { return -1 }
  1105  
  1106  func (w WaitStatus) Signaled() bool { return false }
  1107  
  1108  func (w WaitStatus) TrapCause() int { return -1 }
  1109  
  1110  // Timespec is an invented structure on Windows, but here for
  1111  // consistency with the syscall package for other operating systems.
  1112  type Timespec struct {
  1113  	Sec  int64
  1114  	Nsec int64
  1115  }
  1116  
  1117  func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
  1118  
  1119  func NsecToTimespec(nsec int64) (ts Timespec) {
  1120  	ts.Sec = nsec / 1e9
  1121  	ts.Nsec = nsec % 1e9
  1122  	return
  1123  }
  1124  
  1125  // TODO(brainman): fix all needed for net
  1126  
  1127  func Accept(fd Handle) (nfd Handle, sa Sockaddr, err error) { return 0, nil, EWINDOWS }
  1128  func Recvfrom(fd Handle, p []byte, flags int) (n int, from Sockaddr, err error) {
  1129  	return 0, nil, EWINDOWS
  1130  }
  1131  func Sendto(fd Handle, p []byte, flags int, to Sockaddr) (err error)       { return EWINDOWS }
  1132  func SetsockoptTimeval(fd Handle, level, opt int, tv *Timeval) (err error) { return EWINDOWS }
  1133  
  1134  // The Linger struct is wrong but we only noticed after Go 1.
  1135  // sysLinger is the real system call structure.
  1136  
  1137  // BUG(brainman): The definition of Linger is not appropriate for direct use
  1138  // with Setsockopt and Getsockopt.
  1139  // Use SetsockoptLinger instead.
  1140  
  1141  type Linger struct {
  1142  	Onoff  int32
  1143  	Linger int32
  1144  }
  1145  
  1146  type sysLinger struct {
  1147  	Onoff  uint16
  1148  	Linger uint16
  1149  }
  1150  
  1151  type IPMreq struct {
  1152  	Multiaddr [4]byte /* in_addr */
  1153  	Interface [4]byte /* in_addr */
  1154  }
  1155  
  1156  type IPv6Mreq struct {
  1157  	Multiaddr [16]byte /* in6_addr */
  1158  	Interface uint32
  1159  }
  1160  
  1161  func GetsockoptInt(fd Handle, level, opt int) (int, error) { return -1, EWINDOWS }
  1162  
  1163  func SetsockoptLinger(fd Handle, level, opt int, l *Linger) (err error) {
  1164  	sys := sysLinger{Onoff: uint16(l.Onoff), Linger: uint16(l.Linger)}
  1165  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&sys)), int32(unsafe.Sizeof(sys)))
  1166  }
  1167  
  1168  func SetsockoptInet4Addr(fd Handle, level, opt int, value [4]byte) (err error) {
  1169  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&value[0])), 4)
  1170  }
  1171  func SetsockoptIPMreq(fd Handle, level, opt int, mreq *IPMreq) (err error) {
  1172  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(mreq)), int32(unsafe.Sizeof(*mreq)))
  1173  }
  1174  func SetsockoptIPv6Mreq(fd Handle, level, opt int, mreq *IPv6Mreq) (err error) { return EWINDOWS }
  1175  
  1176  func Getpid() (pid int) { return int(getCurrentProcessId()) }
  1177  
  1178  func FindFirstFile(name *uint16, data *Win32finddata) (handle Handle, err error) {
  1179  	// NOTE(rsc): The Win32finddata struct is wrong for the system call:
  1180  	// the two paths are each one uint16 short. Use the correct struct,
  1181  	// a win32finddata1, and then copy the results out.
  1182  	// There is no loss of expressivity here, because the final
  1183  	// uint16, if it is used, is supposed to be a NUL, and Go doesn't need that.
  1184  	// For Go 1.1, we might avoid the allocation of win32finddata1 here
  1185  	// by adding a final Bug [2]uint16 field to the struct and then
  1186  	// adjusting the fields in the result directly.
  1187  	var data1 win32finddata1
  1188  	handle, err = findFirstFile1(name, &data1)
  1189  	if err == nil {
  1190  		copyFindData(data, &data1)
  1191  	}
  1192  	return
  1193  }
  1194  
  1195  func FindNextFile(handle Handle, data *Win32finddata) (err error) {
  1196  	var data1 win32finddata1
  1197  	err = findNextFile1(handle, &data1)
  1198  	if err == nil {
  1199  		copyFindData(data, &data1)
  1200  	}
  1201  	return
  1202  }
  1203  
  1204  func getProcessEntry(pid int) (*ProcessEntry32, error) {
  1205  	snapshot, err := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)
  1206  	if err != nil {
  1207  		return nil, err
  1208  	}
  1209  	defer CloseHandle(snapshot)
  1210  	var procEntry ProcessEntry32
  1211  	procEntry.Size = uint32(unsafe.Sizeof(procEntry))
  1212  	if err = Process32First(snapshot, &procEntry); err != nil {
  1213  		return nil, err
  1214  	}
  1215  	for {
  1216  		if procEntry.ProcessID == uint32(pid) {
  1217  			return &procEntry, nil
  1218  		}
  1219  		err = Process32Next(snapshot, &procEntry)
  1220  		if err != nil {
  1221  			return nil, err
  1222  		}
  1223  	}
  1224  }
  1225  
  1226  func Getppid() (ppid int) {
  1227  	pe, err := getProcessEntry(Getpid())
  1228  	if err != nil {
  1229  		return -1
  1230  	}
  1231  	return int(pe.ParentProcessID)
  1232  }
  1233  
  1234  func fdpath(fd Handle, buf []uint16) ([]uint16, error) {
  1235  	const (
  1236  		FILE_NAME_NORMALIZED = 0
  1237  		VOLUME_NAME_DOS      = 0
  1238  	)
  1239  	for {
  1240  		n, err := getFinalPathNameByHandle(fd, &buf[0], uint32(len(buf)), FILE_NAME_NORMALIZED|VOLUME_NAME_DOS)
  1241  		if err == nil {
  1242  			buf = buf[:n]
  1243  			break
  1244  		}
  1245  		if err != _ERROR_NOT_ENOUGH_MEMORY {
  1246  			return nil, err
  1247  		}
  1248  		buf = append(buf, make([]uint16, n-uint32(len(buf)))...)
  1249  	}
  1250  	return buf, nil
  1251  }
  1252  
  1253  func Fchdir(fd Handle) (err error) {
  1254  	var buf [MAX_PATH + 1]uint16
  1255  	path, err := fdpath(fd, buf[:])
  1256  	if err != nil {
  1257  		return err
  1258  	}
  1259  	// When using VOLUME_NAME_DOS, the path is always pefixed by "\\?\".
  1260  	// That prefix tells the Windows APIs to disable all string parsing and to send
  1261  	// the string that follows it straight to the file system.
  1262  	// Although SetCurrentDirectory and GetCurrentDirectory do support the "\\?\" prefix,
  1263  	// some other Windows APIs don't. If the prefix is not removed here, it will leak
  1264  	// to Getwd, and we don't want such a general-purpose function to always return a
  1265  	// path with the "\\?\" prefix after Fchdir is called.
  1266  	// The downside is that APIs that do support it will parse the path and try to normalize it,
  1267  	// when it's already normalized.
  1268  	if len(path) >= 4 && path[0] == '\\' && path[1] == '\\' && path[2] == '?' && path[3] == '\\' {
  1269  		path = path[4:]
  1270  	}
  1271  	return SetCurrentDirectory(&path[0])
  1272  }
  1273  
  1274  // TODO(brainman): fix all needed for os
  1275  func Link(oldpath, newpath string) (err error) { return EWINDOWS }
  1276  func Symlink(path, link string) (err error)    { return EWINDOWS }
  1277  
  1278  func Fchmod(fd Handle, mode uint32) (err error)        { return EWINDOWS }
  1279  func Chown(path string, uid int, gid int) (err error)  { return EWINDOWS }
  1280  func Lchown(path string, uid int, gid int) (err error) { return EWINDOWS }
  1281  func Fchown(fd Handle, uid int, gid int) (err error)   { return EWINDOWS }
  1282  
  1283  func Getuid() (uid int)                  { return -1 }
  1284  func Geteuid() (euid int)                { return -1 }
  1285  func Getgid() (gid int)                  { return -1 }
  1286  func Getegid() (egid int)                { return -1 }
  1287  func Getgroups() (gids []int, err error) { return nil, EWINDOWS }
  1288  
  1289  type Signal int
  1290  
  1291  func (s Signal) Signal() {}
  1292  
  1293  func (s Signal) String() string {
  1294  	if 0 <= s && int(s) < len(signals) {
  1295  		str := signals[s]
  1296  		if str != "" {
  1297  			return str
  1298  		}
  1299  	}
  1300  	return "signal " + itoa.Itoa(int(s))
  1301  }
  1302  
  1303  func LoadCreateSymbolicLink() error {
  1304  	return procCreateSymbolicLinkW.Find()
  1305  }
  1306  
  1307  // Readlink returns the destination of the named symbolic link.
  1308  func Readlink(path string, buf []byte) (n int, err error) {
  1309  	fd, err := CreateFile(StringToUTF16Ptr(path), GENERIC_READ, 0, nil, OPEN_EXISTING,
  1310  		FILE_FLAG_OPEN_REPARSE_POINT|FILE_FLAG_BACKUP_SEMANTICS, 0)
  1311  	if err != nil {
  1312  		return -1, err
  1313  	}
  1314  	defer CloseHandle(fd)
  1315  
  1316  	rdbbuf := make([]byte, MAXIMUM_REPARSE_DATA_BUFFER_SIZE)
  1317  	var bytesReturned uint32
  1318  	err = DeviceIoControl(fd, FSCTL_GET_REPARSE_POINT, nil, 0, &rdbbuf[0], uint32(len(rdbbuf)), &bytesReturned, nil)
  1319  	if err != nil {
  1320  		return -1, err
  1321  	}
  1322  
  1323  	rdb := (*reparseDataBuffer)(unsafe.Pointer(&rdbbuf[0]))
  1324  	var s string
  1325  	switch rdb.ReparseTag {
  1326  	case IO_REPARSE_TAG_SYMLINK:
  1327  		data := (*symbolicLinkReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
  1328  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
  1329  		s = UTF16ToString(p[data.SubstituteNameOffset/2 : (data.SubstituteNameOffset+data.SubstituteNameLength)/2])
  1330  		if data.Flags&_SYMLINK_FLAG_RELATIVE == 0 {
  1331  			if len(s) >= 4 && s[:4] == `\??\` {
  1332  				s = s[4:]
  1333  				switch {
  1334  				case len(s) >= 2 && s[1] == ':': // \??\C:\foo\bar
  1335  					// do nothing
  1336  				case len(s) >= 4 && s[:4] == `UNC\`: // \??\UNC\foo\bar
  1337  					s = `\\` + s[4:]
  1338  				default:
  1339  					// unexpected; do nothing
  1340  				}
  1341  			} else {
  1342  				// unexpected; do nothing
  1343  			}
  1344  		}
  1345  	case _IO_REPARSE_TAG_MOUNT_POINT:
  1346  		data := (*mountPointReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
  1347  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
  1348  		s = UTF16ToString(p[data.SubstituteNameOffset/2 : (data.SubstituteNameOffset+data.SubstituteNameLength)/2])
  1349  		if len(s) >= 4 && s[:4] == `\??\` { // \??\C:\foo\bar
  1350  			s = s[4:]
  1351  		} else {
  1352  			// unexpected; do nothing
  1353  		}
  1354  	default:
  1355  		// the path is not a symlink or junction but another type of reparse
  1356  		// point
  1357  		return -1, ENOENT
  1358  	}
  1359  	n = copy(buf, []byte(s))
  1360  
  1361  	return n, nil
  1362  }
  1363  
  1364  // Deprecated: CreateIoCompletionPort has the wrong function signature. Use x/sys/windows.CreateIoCompletionPort.
  1365  func CreateIoCompletionPort(filehandle Handle, cphandle Handle, key uint32, threadcnt uint32) (Handle, error) {
  1366  	return createIoCompletionPort(filehandle, cphandle, uintptr(key), threadcnt)
  1367  }
  1368  
  1369  // Deprecated: GetQueuedCompletionStatus has the wrong function signature. Use x/sys/windows.GetQueuedCompletionStatus.
  1370  func GetQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uint32, overlapped **Overlapped, timeout uint32) error {
  1371  	var ukey uintptr
  1372  	var pukey *uintptr
  1373  	if key != nil {
  1374  		ukey = uintptr(*key)
  1375  		pukey = &ukey
  1376  	}
  1377  	err := getQueuedCompletionStatus(cphandle, qty, pukey, overlapped, timeout)
  1378  	if key != nil {
  1379  		*key = uint32(ukey)
  1380  		if uintptr(*key) != ukey && err == nil {
  1381  			err = errorspkg.New("GetQueuedCompletionStatus returned key overflow")
  1382  		}
  1383  	}
  1384  	return err
  1385  }
  1386  
  1387  // Deprecated: PostQueuedCompletionStatus has the wrong function signature. Use x/sys/windows.PostQueuedCompletionStatus.
  1388  func PostQueuedCompletionStatus(cphandle Handle, qty uint32, key uint32, overlapped *Overlapped) error {
  1389  	return postQueuedCompletionStatus(cphandle, qty, uintptr(key), overlapped)
  1390  }
  1391  
  1392  // newProcThreadAttributeList allocates new PROC_THREAD_ATTRIBUTE_LIST, with
  1393  // the requested maximum number of attributes, which must be cleaned up by
  1394  // deleteProcThreadAttributeList.
  1395  func newProcThreadAttributeList(maxAttrCount uint32) (*_PROC_THREAD_ATTRIBUTE_LIST, error) {
  1396  	var size uintptr
  1397  	err := initializeProcThreadAttributeList(nil, maxAttrCount, 0, &size)
  1398  	if err != ERROR_INSUFFICIENT_BUFFER {
  1399  		if err == nil {
  1400  			return nil, errorspkg.New("unable to query buffer size from InitializeProcThreadAttributeList")
  1401  		}
  1402  		return nil, err
  1403  	}
  1404  	// size is guaranteed to be ≥1 by initializeProcThreadAttributeList.
  1405  	al := (*_PROC_THREAD_ATTRIBUTE_LIST)(unsafe.Pointer(&make([]byte, size)[0]))
  1406  	err = initializeProcThreadAttributeList(al, maxAttrCount, 0, &size)
  1407  	if err != nil {
  1408  		return nil, err
  1409  	}
  1410  	return al, nil
  1411  }
  1412  
  1413  // RegEnumKeyEx enumerates the subkeys of an open registry key.
  1414  // Each call retrieves information about one subkey. name is
  1415  // a buffer that should be large enough to hold the name of the
  1416  // subkey plus a null terminating character. nameLen is its
  1417  // length. On return, nameLen will contain the actual length of the
  1418  // subkey.
  1419  //
  1420  // Should name not be large enough to hold the subkey, this function
  1421  // will return ERROR_MORE_DATA, and must be called again with an
  1422  // appropriately sized buffer.
  1423  //
  1424  // reserved must be nil. class and classLen behave like name and nameLen
  1425  // but for the class of the subkey, except that they are optional.
  1426  // lastWriteTime, if not nil, will be populated with the time the subkey
  1427  // was last written.
  1428  //
  1429  // The caller must enumerate all subkeys in order. That is
  1430  // RegEnumKeyEx must be called with index starting at 0, incrementing
  1431  // the index until the function returns ERROR_NO_MORE_ITEMS, or with
  1432  // the index of the last subkey (obtainable from RegQueryInfoKey),
  1433  // decrementing until index 0 is enumerated.
  1434  //
  1435  // Successive calls to this API must happen on the same OS thread,
  1436  // so call runtime.LockOSThread before calling this function.
  1437  func RegEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno error) {
  1438  	return regEnumKeyEx(key, index, name, nameLen, reserved, class, classLen, lastWriteTime)
  1439  }
  1440  

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