github.com/gocuntian/go@v0.0.0-20160610041250-fee02d270bf8/src/syscall/syscall_windows.go (about)

     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/race"
    12  	"sync"
    13  	"unicode/utf16"
    14  	"unsafe"
    15  )
    16  
    17  //go:generate go run mksyscall_windows.go -systemdll -output zsyscall_windows.go syscall_windows.go security_windows.go
    18  
    19  type Handle uintptr
    20  
    21  const InvalidHandle = ^Handle(0)
    22  
    23  // StringToUTF16 returns the UTF-16 encoding of the UTF-8 string s,
    24  // with a terminating NUL added. If s contains a NUL byte this
    25  // function panics instead of returning an error.
    26  //
    27  // Deprecated: Use UTF16FromString instead.
    28  func StringToUTF16(s string) []uint16 {
    29  	a, err := UTF16FromString(s)
    30  	if err != nil {
    31  		panic("syscall: string with NUL passed to StringToUTF16")
    32  	}
    33  	return a
    34  }
    35  
    36  // UTF16FromString returns the UTF-16 encoding of the UTF-8 string
    37  // s, with a terminating NUL added. If s contains a NUL byte at any
    38  // location, it returns (nil, EINVAL).
    39  func UTF16FromString(s string) ([]uint16, error) {
    40  	for i := 0; i < len(s); i++ {
    41  		if s[i] == 0 {
    42  			return nil, EINVAL
    43  		}
    44  	}
    45  	return utf16.Encode([]rune(s + "\x00")), nil
    46  }
    47  
    48  // UTF16ToString returns the UTF-8 encoding of the UTF-16 sequence s,
    49  // with a terminating NUL removed.
    50  func UTF16ToString(s []uint16) string {
    51  	for i, v := range s {
    52  		if v == 0 {
    53  			s = s[0:i]
    54  			break
    55  		}
    56  	}
    57  	return string(utf16.Decode(s))
    58  }
    59  
    60  // StringToUTF16Ptr returns pointer to the UTF-16 encoding of
    61  // the UTF-8 string s, with a terminating NUL added. If s
    62  // If s contains a NUL byte this function panics instead of
    63  // returning an error.
    64  //
    65  // Deprecated: Use UTF16PtrFromString instead.
    66  func StringToUTF16Ptr(s string) *uint16 { return &StringToUTF16(s)[0] }
    67  
    68  // UTF16PtrFromString returns pointer to the UTF-16 encoding of
    69  // the UTF-8 string s, with a terminating NUL added. If s
    70  // contains a NUL byte at any location, it returns (nil, EINVAL).
    71  func UTF16PtrFromString(s string) (*uint16, error) {
    72  	a, err := UTF16FromString(s)
    73  	if err != nil {
    74  		return nil, err
    75  	}
    76  	return &a[0], nil
    77  }
    78  
    79  func Getpagesize() int { return 4096 }
    80  
    81  // Errno is the Windows error number.
    82  type Errno uintptr
    83  
    84  func langid(pri, sub uint16) uint32 { return uint32(sub)<<10 | uint32(pri) }
    85  
    86  // FormatMessage is deprecated (msgsrc should be uintptr, not uint32, but can
    87  // not be changed due to the Go 1 compatibility guarantee).
    88  //
    89  // Deprecated: Use FormatMessage from golang.org/x/sys/windows instead.
    90  func FormatMessage(flags uint32, msgsrc uint32, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) {
    91  	return formatMessage(flags, uintptr(msgsrc), msgid, langid, buf, args)
    92  }
    93  
    94  func (e Errno) Error() string {
    95  	// deal with special go errors
    96  	idx := int(e - APPLICATION_ERROR)
    97  	if 0 <= idx && idx < len(errors) {
    98  		return errors[idx]
    99  	}
   100  	// ask windows for the remaining errors
   101  	var flags uint32 = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ARGUMENT_ARRAY | FORMAT_MESSAGE_IGNORE_INSERTS
   102  	b := make([]uint16, 300)
   103  	n, err := formatMessage(flags, 0, uint32(e), langid(LANG_ENGLISH, SUBLANG_ENGLISH_US), b, nil)
   104  	if err != nil {
   105  		n, err = formatMessage(flags, 0, uint32(e), 0, b, nil)
   106  		if err != nil {
   107  			return "winapi error #" + itoa(int(e))
   108  		}
   109  	}
   110  	// trim terminating \r and \n
   111  	for ; n > 0 && (b[n-1] == '\n' || b[n-1] == '\r'); n-- {
   112  	}
   113  	return string(utf16.Decode(b[:n]))
   114  }
   115  
   116  func (e Errno) Temporary() bool {
   117  	return e == EINTR || e == EMFILE || e.Timeout()
   118  }
   119  
   120  func (e Errno) Timeout() bool {
   121  	return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
   122  }
   123  
   124  // Implemented in runtime/syscall_windows.go.
   125  func compileCallback(fn interface{}, cleanstack bool) uintptr
   126  
   127  // Converts a Go function to a function pointer conforming
   128  // to the stdcall calling convention. This is useful when
   129  // interoperating with Windows code requiring callbacks.
   130  func NewCallback(fn interface{}) uintptr {
   131  	return compileCallback(fn, true)
   132  }
   133  
   134  // Converts a Go function to a function pointer conforming
   135  // to the cdecl calling convention. This is useful when
   136  // interoperating with Windows code requiring callbacks.
   137  func NewCallbackCDecl(fn interface{}) uintptr {
   138  	return compileCallback(fn, false)
   139  }
   140  
   141  // windows api calls
   142  
   143  //sys	GetLastError() (lasterr error)
   144  //sys	LoadLibrary(libname string) (handle Handle, err error) = LoadLibraryW
   145  //sys	FreeLibrary(handle Handle) (err error)
   146  //sys	GetProcAddress(module Handle, procname string) (proc uintptr, err error)
   147  //sys	GetVersion() (ver uint32, err error)
   148  //sys	formatMessage(flags uint32, msgsrc uintptr, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) = FormatMessageW
   149  //sys	ExitProcess(exitcode uint32)
   150  //sys	CreateFile(name *uint16, access uint32, mode uint32, sa *SecurityAttributes, createmode uint32, attrs uint32, templatefile int32) (handle Handle, err error) [failretval==InvalidHandle] = CreateFileW
   151  //sys	ReadFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error)
   152  //sys	WriteFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error)
   153  //sys	SetFilePointer(handle Handle, lowoffset int32, highoffsetptr *int32, whence uint32) (newlowoffset uint32, err error) [failretval==0xffffffff]
   154  //sys	CloseHandle(handle Handle) (err error)
   155  //sys	GetStdHandle(stdhandle int) (handle Handle, err error) [failretval==InvalidHandle]
   156  //sys	findFirstFile1(name *uint16, data *win32finddata1) (handle Handle, err error) [failretval==InvalidHandle] = FindFirstFileW
   157  //sys	findNextFile1(handle Handle, data *win32finddata1) (err error) = FindNextFileW
   158  //sys	FindClose(handle Handle) (err error)
   159  //sys	GetFileInformationByHandle(handle Handle, data *ByHandleFileInformation) (err error)
   160  //sys	GetCurrentDirectory(buflen uint32, buf *uint16) (n uint32, err error) = GetCurrentDirectoryW
   161  //sys	SetCurrentDirectory(path *uint16) (err error) = SetCurrentDirectoryW
   162  //sys	CreateDirectory(path *uint16, sa *SecurityAttributes) (err error) = CreateDirectoryW
   163  //sys	RemoveDirectory(path *uint16) (err error) = RemoveDirectoryW
   164  //sys	DeleteFile(path *uint16) (err error) = DeleteFileW
   165  //sys	MoveFile(from *uint16, to *uint16) (err error) = MoveFileW
   166  //sys	GetComputerName(buf *uint16, n *uint32) (err error) = GetComputerNameW
   167  //sys	SetEndOfFile(handle Handle) (err error)
   168  //sys	GetSystemTimeAsFileTime(time *Filetime)
   169  //sys	GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, err error) [failretval==0xffffffff]
   170  //sys	CreateIoCompletionPort(filehandle Handle, cphandle Handle, key uint32, threadcnt uint32) (handle Handle, err error)
   171  //sys	GetQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uint32, overlapped **Overlapped, timeout uint32) (err error)
   172  //sys	PostQueuedCompletionStatus(cphandle Handle, qty uint32, key uint32, overlapped *Overlapped) (err error)
   173  //sys	CancelIo(s Handle) (err error)
   174  //sys	CancelIoEx(s Handle, o *Overlapped) (err error)
   175  //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
   176  //sys	OpenProcess(da uint32, inheritHandle bool, pid uint32) (handle Handle, err error)
   177  //sys	TerminateProcess(handle Handle, exitcode uint32) (err error)
   178  //sys	GetExitCodeProcess(handle Handle, exitcode *uint32) (err error)
   179  //sys	GetStartupInfo(startupInfo *StartupInfo) (err error) = GetStartupInfoW
   180  //sys	GetCurrentProcess() (pseudoHandle Handle, err error)
   181  //sys	GetProcessTimes(handle Handle, creationTime *Filetime, exitTime *Filetime, kernelTime *Filetime, userTime *Filetime) (err error)
   182  //sys	DuplicateHandle(hSourceProcessHandle Handle, hSourceHandle Handle, hTargetProcessHandle Handle, lpTargetHandle *Handle, dwDesiredAccess uint32, bInheritHandle bool, dwOptions uint32) (err error)
   183  //sys	WaitForSingleObject(handle Handle, waitMilliseconds uint32) (event uint32, err error) [failretval==0xffffffff]
   184  //sys	GetTempPath(buflen uint32, buf *uint16) (n uint32, err error) = GetTempPathW
   185  //sys	CreatePipe(readhandle *Handle, writehandle *Handle, sa *SecurityAttributes, size uint32) (err error)
   186  //sys	GetFileType(filehandle Handle) (n uint32, err error)
   187  //sys	CryptAcquireContext(provhandle *Handle, container *uint16, provider *uint16, provtype uint32, flags uint32) (err error) = advapi32.CryptAcquireContextW
   188  //sys	CryptReleaseContext(provhandle Handle, flags uint32) (err error) = advapi32.CryptReleaseContext
   189  //sys	CryptGenRandom(provhandle Handle, buflen uint32, buf *byte) (err error) = advapi32.CryptGenRandom
   190  //sys	GetEnvironmentStrings() (envs *uint16, err error) [failretval==nil] = kernel32.GetEnvironmentStringsW
   191  //sys	FreeEnvironmentStrings(envs *uint16) (err error) = kernel32.FreeEnvironmentStringsW
   192  //sys	GetEnvironmentVariable(name *uint16, buffer *uint16, size uint32) (n uint32, err error) = kernel32.GetEnvironmentVariableW
   193  //sys	SetEnvironmentVariable(name *uint16, value *uint16) (err error) = kernel32.SetEnvironmentVariableW
   194  //sys	SetFileTime(handle Handle, ctime *Filetime, atime *Filetime, wtime *Filetime) (err error)
   195  //sys	GetFileAttributes(name *uint16) (attrs uint32, err error) [failretval==INVALID_FILE_ATTRIBUTES] = kernel32.GetFileAttributesW
   196  //sys	SetFileAttributes(name *uint16, attrs uint32) (err error) = kernel32.SetFileAttributesW
   197  //sys	GetFileAttributesEx(name *uint16, level uint32, info *byte) (err error) = kernel32.GetFileAttributesExW
   198  //sys	GetCommandLine() (cmd *uint16) = kernel32.GetCommandLineW
   199  //sys	CommandLineToArgv(cmd *uint16, argc *int32) (argv *[8192]*[8192]uint16, err error) [failretval==nil] = shell32.CommandLineToArgvW
   200  //sys	LocalFree(hmem Handle) (handle Handle, err error) [failretval!=0]
   201  //sys	SetHandleInformation(handle Handle, mask uint32, flags uint32) (err error)
   202  //sys	FlushFileBuffers(handle Handle) (err error)
   203  //sys	GetFullPathName(path *uint16, buflen uint32, buf *uint16, fname **uint16) (n uint32, err error) = kernel32.GetFullPathNameW
   204  //sys	GetLongPathName(path *uint16, buf *uint16, buflen uint32) (n uint32, err error) = kernel32.GetLongPathNameW
   205  //sys	GetShortPathName(longpath *uint16, shortpath *uint16, buflen uint32) (n uint32, err error) = kernel32.GetShortPathNameW
   206  //sys	CreateFileMapping(fhandle Handle, sa *SecurityAttributes, prot uint32, maxSizeHigh uint32, maxSizeLow uint32, name *uint16) (handle Handle, err error) = kernel32.CreateFileMappingW
   207  //sys	MapViewOfFile(handle Handle, access uint32, offsetHigh uint32, offsetLow uint32, length uintptr) (addr uintptr, err error)
   208  //sys	UnmapViewOfFile(addr uintptr) (err error)
   209  //sys	FlushViewOfFile(addr uintptr, length uintptr) (err error)
   210  //sys	VirtualLock(addr uintptr, length uintptr) (err error)
   211  //sys	VirtualUnlock(addr uintptr, length uintptr) (err error)
   212  //sys	TransmitFile(s Handle, handle Handle, bytesToWrite uint32, bytsPerSend uint32, overlapped *Overlapped, transmitFileBuf *TransmitFileBuffers, flags uint32) (err error) = mswsock.TransmitFile
   213  //sys	ReadDirectoryChanges(handle Handle, buf *byte, buflen uint32, watchSubTree bool, mask uint32, retlen *uint32, overlapped *Overlapped, completionRoutine uintptr) (err error) = kernel32.ReadDirectoryChangesW
   214  //sys	CertOpenSystemStore(hprov Handle, name *uint16) (store Handle, err error) = crypt32.CertOpenSystemStoreW
   215  //sys   CertOpenStore(storeProvider uintptr, msgAndCertEncodingType uint32, cryptProv uintptr, flags uint32, para uintptr) (handle Handle, err error) [failretval==InvalidHandle] = crypt32.CertOpenStore
   216  //sys	CertEnumCertificatesInStore(store Handle, prevContext *CertContext) (context *CertContext, err error) [failretval==nil] = crypt32.CertEnumCertificatesInStore
   217  //sys   CertAddCertificateContextToStore(store Handle, certContext *CertContext, addDisposition uint32, storeContext **CertContext) (err error) = crypt32.CertAddCertificateContextToStore
   218  //sys	CertCloseStore(store Handle, flags uint32) (err error) = crypt32.CertCloseStore
   219  //sys   CertGetCertificateChain(engine Handle, leaf *CertContext, time *Filetime, additionalStore Handle, para *CertChainPara, flags uint32, reserved uintptr, chainCtx **CertChainContext) (err error) = crypt32.CertGetCertificateChain
   220  //sys   CertFreeCertificateChain(ctx *CertChainContext) = crypt32.CertFreeCertificateChain
   221  //sys   CertCreateCertificateContext(certEncodingType uint32, certEncoded *byte, encodedLen uint32) (context *CertContext, err error) [failretval==nil] = crypt32.CertCreateCertificateContext
   222  //sys   CertFreeCertificateContext(ctx *CertContext) (err error) = crypt32.CertFreeCertificateContext
   223  //sys   CertVerifyCertificateChainPolicy(policyOID uintptr, chain *CertChainContext, para *CertChainPolicyPara, status *CertChainPolicyStatus) (err error) = crypt32.CertVerifyCertificateChainPolicy
   224  //sys	RegOpenKeyEx(key Handle, subkey *uint16, options uint32, desiredAccess uint32, result *Handle) (regerrno error) = advapi32.RegOpenKeyExW
   225  //sys	RegCloseKey(key Handle) (regerrno error) = advapi32.RegCloseKey
   226  //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
   227  //sys	RegEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno error) = advapi32.RegEnumKeyExW
   228  //sys	RegQueryValueEx(key Handle, name *uint16, reserved *uint32, valtype *uint32, buf *byte, buflen *uint32) (regerrno error) = advapi32.RegQueryValueExW
   229  //sys	getCurrentProcessId() (pid uint32) = kernel32.GetCurrentProcessId
   230  //sys	GetConsoleMode(console Handle, mode *uint32) (err error) = kernel32.GetConsoleMode
   231  //sys	WriteConsole(console Handle, buf *uint16, towrite uint32, written *uint32, reserved *byte) (err error) = kernel32.WriteConsoleW
   232  //sys	ReadConsole(console Handle, buf *uint16, toread uint32, read *uint32, inputControl *byte) (err error) = kernel32.ReadConsoleW
   233  //sys	CreateToolhelp32Snapshot(flags uint32, processId uint32) (handle Handle, err error) [failretval==InvalidHandle] = kernel32.CreateToolhelp32Snapshot
   234  //sys	Process32First(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32FirstW
   235  //sys	Process32Next(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32NextW
   236  //sys	DeviceIoControl(handle Handle, ioControlCode uint32, inBuffer *byte, inBufferSize uint32, outBuffer *byte, outBufferSize uint32, bytesReturned *uint32, overlapped *Overlapped) (err error)
   237  // This function returns 1 byte BOOLEAN rather than the 4 byte BOOL.
   238  //sys	CreateSymbolicLink(symlinkfilename *uint16, targetfilename *uint16, flags uint32) (err error) [failretval&0xff==0] = CreateSymbolicLinkW
   239  //sys	CreateHardLink(filename *uint16, existingfilename *uint16, reserved uintptr) (err error) [failretval&0xff==0] = CreateHardLinkW
   240  
   241  // syscall interface implementation for other packages
   242  
   243  func Exit(code int) { ExitProcess(uint32(code)) }
   244  
   245  func makeInheritSa() *SecurityAttributes {
   246  	var sa SecurityAttributes
   247  	sa.Length = uint32(unsafe.Sizeof(sa))
   248  	sa.InheritHandle = 1
   249  	return &sa
   250  }
   251  
   252  func Open(path string, mode int, perm uint32) (fd Handle, err error) {
   253  	if len(path) == 0 {
   254  		return InvalidHandle, ERROR_FILE_NOT_FOUND
   255  	}
   256  	pathp, err := UTF16PtrFromString(path)
   257  	if err != nil {
   258  		return InvalidHandle, err
   259  	}
   260  	var access uint32
   261  	switch mode & (O_RDONLY | O_WRONLY | O_RDWR) {
   262  	case O_RDONLY:
   263  		access = GENERIC_READ
   264  	case O_WRONLY:
   265  		access = GENERIC_WRITE
   266  	case O_RDWR:
   267  		access = GENERIC_READ | GENERIC_WRITE
   268  	}
   269  	if mode&O_CREAT != 0 {
   270  		access |= GENERIC_WRITE
   271  	}
   272  	if mode&O_APPEND != 0 {
   273  		access &^= GENERIC_WRITE
   274  		access |= FILE_APPEND_DATA
   275  	}
   276  	sharemode := uint32(FILE_SHARE_READ | FILE_SHARE_WRITE)
   277  	var sa *SecurityAttributes
   278  	if mode&O_CLOEXEC == 0 {
   279  		sa = makeInheritSa()
   280  	}
   281  	var createmode uint32
   282  	switch {
   283  	case mode&(O_CREAT|O_EXCL) == (O_CREAT | O_EXCL):
   284  		createmode = CREATE_NEW
   285  	case mode&(O_CREAT|O_TRUNC) == (O_CREAT | O_TRUNC):
   286  		createmode = CREATE_ALWAYS
   287  	case mode&O_CREAT == O_CREAT:
   288  		createmode = OPEN_ALWAYS
   289  	case mode&O_TRUNC == O_TRUNC:
   290  		createmode = TRUNCATE_EXISTING
   291  	default:
   292  		createmode = OPEN_EXISTING
   293  	}
   294  	h, e := CreateFile(pathp, access, sharemode, sa, createmode, FILE_ATTRIBUTE_NORMAL, 0)
   295  	return h, e
   296  }
   297  
   298  func Read(fd Handle, p []byte) (n int, err error) {
   299  	var done uint32
   300  	e := ReadFile(fd, p, &done, nil)
   301  	if e != nil {
   302  		if e == ERROR_BROKEN_PIPE {
   303  			// NOTE(brainman): work around ERROR_BROKEN_PIPE is returned on reading EOF from stdin
   304  			return 0, nil
   305  		}
   306  		return 0, e
   307  	}
   308  	if race.Enabled {
   309  		if done > 0 {
   310  			race.WriteRange(unsafe.Pointer(&p[0]), int(done))
   311  		}
   312  		race.Acquire(unsafe.Pointer(&ioSync))
   313  	}
   314  	if msanenabled && done > 0 {
   315  		msanWrite(unsafe.Pointer(&p[0]), int(done))
   316  	}
   317  	return int(done), nil
   318  }
   319  
   320  func Write(fd Handle, p []byte) (n int, err error) {
   321  	if race.Enabled {
   322  		race.ReleaseMerge(unsafe.Pointer(&ioSync))
   323  	}
   324  	var done uint32
   325  	e := WriteFile(fd, p, &done, nil)
   326  	if e != nil {
   327  		return 0, e
   328  	}
   329  	if race.Enabled && done > 0 {
   330  		race.ReadRange(unsafe.Pointer(&p[0]), int(done))
   331  	}
   332  	if msanenabled && done > 0 {
   333  		msanRead(unsafe.Pointer(&p[0]), int(done))
   334  	}
   335  	return int(done), nil
   336  }
   337  
   338  var ioSync int64
   339  
   340  func Seek(fd Handle, offset int64, whence int) (newoffset int64, err error) {
   341  	var w uint32
   342  	switch whence {
   343  	case 0:
   344  		w = FILE_BEGIN
   345  	case 1:
   346  		w = FILE_CURRENT
   347  	case 2:
   348  		w = FILE_END
   349  	}
   350  	hi := int32(offset >> 32)
   351  	lo := int32(offset)
   352  	// use GetFileType to check pipe, pipe can't do seek
   353  	ft, _ := GetFileType(fd)
   354  	if ft == FILE_TYPE_PIPE {
   355  		return 0, EPIPE
   356  	}
   357  	rlo, e := SetFilePointer(fd, lo, &hi, w)
   358  	if e != nil {
   359  		return 0, e
   360  	}
   361  	return int64(hi)<<32 + int64(rlo), nil
   362  }
   363  
   364  func Close(fd Handle) (err error) {
   365  	return CloseHandle(fd)
   366  }
   367  
   368  var (
   369  	Stdin  = getStdHandle(STD_INPUT_HANDLE)
   370  	Stdout = getStdHandle(STD_OUTPUT_HANDLE)
   371  	Stderr = getStdHandle(STD_ERROR_HANDLE)
   372  )
   373  
   374  func getStdHandle(h int) (fd Handle) {
   375  	r, _ := GetStdHandle(h)
   376  	CloseOnExec(r)
   377  	return r
   378  }
   379  
   380  const ImplementsGetwd = true
   381  
   382  func Getwd() (wd string, err error) {
   383  	b := make([]uint16, 300)
   384  	n, e := GetCurrentDirectory(uint32(len(b)), &b[0])
   385  	if e != nil {
   386  		return "", e
   387  	}
   388  	return string(utf16.Decode(b[0:n])), nil
   389  }
   390  
   391  func Chdir(path string) (err error) {
   392  	pathp, err := UTF16PtrFromString(path)
   393  	if err != nil {
   394  		return err
   395  	}
   396  	return SetCurrentDirectory(pathp)
   397  }
   398  
   399  func Mkdir(path string, mode uint32) (err error) {
   400  	pathp, err := UTF16PtrFromString(path)
   401  	if err != nil {
   402  		return err
   403  	}
   404  	return CreateDirectory(pathp, nil)
   405  }
   406  
   407  func Rmdir(path string) (err error) {
   408  	pathp, err := UTF16PtrFromString(path)
   409  	if err != nil {
   410  		return err
   411  	}
   412  	return RemoveDirectory(pathp)
   413  }
   414  
   415  func Unlink(path string) (err error) {
   416  	pathp, err := UTF16PtrFromString(path)
   417  	if err != nil {
   418  		return err
   419  	}
   420  	return DeleteFile(pathp)
   421  }
   422  
   423  func Rename(oldpath, newpath string) (err error) {
   424  	from, err := UTF16PtrFromString(oldpath)
   425  	if err != nil {
   426  		return err
   427  	}
   428  	to, err := UTF16PtrFromString(newpath)
   429  	if err != nil {
   430  		return err
   431  	}
   432  	return MoveFile(from, to)
   433  }
   434  
   435  func ComputerName() (name string, err error) {
   436  	var n uint32 = MAX_COMPUTERNAME_LENGTH + 1
   437  	b := make([]uint16, n)
   438  	e := GetComputerName(&b[0], &n)
   439  	if e != nil {
   440  		return "", e
   441  	}
   442  	return string(utf16.Decode(b[0:n])), nil
   443  }
   444  
   445  func Ftruncate(fd Handle, length int64) (err error) {
   446  	curoffset, e := Seek(fd, 0, 1)
   447  	if e != nil {
   448  		return e
   449  	}
   450  	defer Seek(fd, curoffset, 0)
   451  	_, e = Seek(fd, length, 0)
   452  	if e != nil {
   453  		return e
   454  	}
   455  	e = SetEndOfFile(fd)
   456  	if e != nil {
   457  		return e
   458  	}
   459  	return nil
   460  }
   461  
   462  func Gettimeofday(tv *Timeval) (err error) {
   463  	var ft Filetime
   464  	GetSystemTimeAsFileTime(&ft)
   465  	*tv = NsecToTimeval(ft.Nanoseconds())
   466  	return nil
   467  }
   468  
   469  func Pipe(p []Handle) (err error) {
   470  	if len(p) != 2 {
   471  		return EINVAL
   472  	}
   473  	var r, w Handle
   474  	e := CreatePipe(&r, &w, makeInheritSa(), 0)
   475  	if e != nil {
   476  		return e
   477  	}
   478  	p[0] = r
   479  	p[1] = w
   480  	return nil
   481  }
   482  
   483  func Utimes(path string, tv []Timeval) (err error) {
   484  	if len(tv) != 2 {
   485  		return EINVAL
   486  	}
   487  	pathp, e := UTF16PtrFromString(path)
   488  	if e != nil {
   489  		return e
   490  	}
   491  	h, e := CreateFile(pathp,
   492  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
   493  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
   494  	if e != nil {
   495  		return e
   496  	}
   497  	defer Close(h)
   498  	a := NsecToFiletime(tv[0].Nanoseconds())
   499  	w := NsecToFiletime(tv[1].Nanoseconds())
   500  	return SetFileTime(h, nil, &a, &w)
   501  }
   502  
   503  func UtimesNano(path string, ts []Timespec) (err error) {
   504  	if len(ts) != 2 {
   505  		return EINVAL
   506  	}
   507  	pathp, e := UTF16PtrFromString(path)
   508  	if e != nil {
   509  		return e
   510  	}
   511  	h, e := CreateFile(pathp,
   512  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
   513  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
   514  	if e != nil {
   515  		return e
   516  	}
   517  	defer Close(h)
   518  	a := NsecToFiletime(TimespecToNsec(ts[0]))
   519  	w := NsecToFiletime(TimespecToNsec(ts[1]))
   520  	return SetFileTime(h, nil, &a, &w)
   521  }
   522  
   523  func Fsync(fd Handle) (err error) {
   524  	return FlushFileBuffers(fd)
   525  }
   526  
   527  func Chmod(path string, mode uint32) (err error) {
   528  	if mode == 0 {
   529  		return EINVAL
   530  	}
   531  	p, e := UTF16PtrFromString(path)
   532  	if e != nil {
   533  		return e
   534  	}
   535  	attrs, e := GetFileAttributes(p)
   536  	if e != nil {
   537  		return e
   538  	}
   539  	if mode&S_IWRITE != 0 {
   540  		attrs &^= FILE_ATTRIBUTE_READONLY
   541  	} else {
   542  		attrs |= FILE_ATTRIBUTE_READONLY
   543  	}
   544  	return SetFileAttributes(p, attrs)
   545  }
   546  
   547  func LoadCancelIoEx() error {
   548  	return procCancelIoEx.Find()
   549  }
   550  
   551  func LoadSetFileCompletionNotificationModes() error {
   552  	return procSetFileCompletionNotificationModes.Find()
   553  }
   554  
   555  // net api calls
   556  
   557  const socket_error = uintptr(^uint32(0))
   558  
   559  //sys	WSAStartup(verreq uint32, data *WSAData) (sockerr error) = ws2_32.WSAStartup
   560  //sys	WSACleanup() (err error) [failretval==socket_error] = ws2_32.WSACleanup
   561  //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
   562  //sys	socket(af int32, typ int32, protocol int32) (handle Handle, err error) [failretval==InvalidHandle] = ws2_32.socket
   563  //sys	Setsockopt(s Handle, level int32, optname int32, optval *byte, optlen int32) (err error) [failretval==socket_error] = ws2_32.setsockopt
   564  //sys	Getsockopt(s Handle, level int32, optname int32, optval *byte, optlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockopt
   565  //sys	bind(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.bind
   566  //sys	connect(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.connect
   567  //sys	getsockname(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockname
   568  //sys	getpeername(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getpeername
   569  //sys	listen(s Handle, backlog int32) (err error) [failretval==socket_error] = ws2_32.listen
   570  //sys	shutdown(s Handle, how int32) (err error) [failretval==socket_error] = ws2_32.shutdown
   571  //sys	Closesocket(s Handle) (err error) [failretval==socket_error] = ws2_32.closesocket
   572  //sys	AcceptEx(ls Handle, as Handle, buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, recvd *uint32, overlapped *Overlapped) (err error) = mswsock.AcceptEx
   573  //sys	GetAcceptExSockaddrs(buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, lrsa **RawSockaddrAny, lrsalen *int32, rrsa **RawSockaddrAny, rrsalen *int32) = mswsock.GetAcceptExSockaddrs
   574  //sys	WSARecv(s Handle, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSARecv
   575  //sys	WSASend(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSASend
   576  //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
   577  //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
   578  //sys	GetHostByName(name string) (h *Hostent, err error) [failretval==nil] = ws2_32.gethostbyname
   579  //sys	GetServByName(name string, proto string) (s *Servent, err error) [failretval==nil] = ws2_32.getservbyname
   580  //sys	Ntohs(netshort uint16) (u uint16) = ws2_32.ntohs
   581  //sys	GetProtoByName(name string) (p *Protoent, err error) [failretval==nil] = ws2_32.getprotobyname
   582  //sys	DnsQuery(name string, qtype uint16, options uint32, extra *byte, qrs **DNSRecord, pr *byte) (status error) = dnsapi.DnsQuery_W
   583  //sys	DnsRecordListFree(rl *DNSRecord, freetype uint32) = dnsapi.DnsRecordListFree
   584  //sys	DnsNameCompare(name1 *uint16, name2 *uint16) (same bool) = dnsapi.DnsNameCompare_W
   585  //sys	GetAddrInfoW(nodename *uint16, servicename *uint16, hints *AddrinfoW, result **AddrinfoW) (sockerr error) = ws2_32.GetAddrInfoW
   586  //sys	FreeAddrInfoW(addrinfo *AddrinfoW) = ws2_32.FreeAddrInfoW
   587  //sys	GetIfEntry(pIfRow *MibIfRow) (errcode error) = iphlpapi.GetIfEntry
   588  //sys	GetAdaptersInfo(ai *IpAdapterInfo, ol *uint32) (errcode error) = iphlpapi.GetAdaptersInfo
   589  //sys	SetFileCompletionNotificationModes(handle Handle, flags uint8) (err error) = kernel32.SetFileCompletionNotificationModes
   590  //sys	WSAEnumProtocols(protocols *int32, protocolBuffer *WSAProtocolInfo, bufferLength *uint32) (n int32, err error) [failretval==-1] = ws2_32.WSAEnumProtocolsW
   591  
   592  // For testing: clients can set this flag to force
   593  // creation of IPv6 sockets to return EAFNOSUPPORT.
   594  var SocketDisableIPv6 bool
   595  
   596  type RawSockaddrInet4 struct {
   597  	Family uint16
   598  	Port   uint16
   599  	Addr   [4]byte /* in_addr */
   600  	Zero   [8]uint8
   601  }
   602  
   603  type RawSockaddrInet6 struct {
   604  	Family   uint16
   605  	Port     uint16
   606  	Flowinfo uint32
   607  	Addr     [16]byte /* in6_addr */
   608  	Scope_id uint32
   609  }
   610  
   611  type RawSockaddr struct {
   612  	Family uint16
   613  	Data   [14]int8
   614  }
   615  
   616  type RawSockaddrAny struct {
   617  	Addr RawSockaddr
   618  	Pad  [96]int8
   619  }
   620  
   621  type Sockaddr interface {
   622  	sockaddr() (ptr unsafe.Pointer, len int32, err error) // lowercase; only we can define Sockaddrs
   623  }
   624  
   625  type SockaddrInet4 struct {
   626  	Port int
   627  	Addr [4]byte
   628  	raw  RawSockaddrInet4
   629  }
   630  
   631  func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, int32, error) {
   632  	if sa.Port < 0 || sa.Port > 0xFFFF {
   633  		return nil, 0, EINVAL
   634  	}
   635  	sa.raw.Family = AF_INET
   636  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   637  	p[0] = byte(sa.Port >> 8)
   638  	p[1] = byte(sa.Port)
   639  	for i := 0; i < len(sa.Addr); i++ {
   640  		sa.raw.Addr[i] = sa.Addr[i]
   641  	}
   642  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
   643  }
   644  
   645  type SockaddrInet6 struct {
   646  	Port   int
   647  	ZoneId uint32
   648  	Addr   [16]byte
   649  	raw    RawSockaddrInet6
   650  }
   651  
   652  func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, int32, error) {
   653  	if sa.Port < 0 || sa.Port > 0xFFFF {
   654  		return nil, 0, EINVAL
   655  	}
   656  	sa.raw.Family = AF_INET6
   657  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   658  	p[0] = byte(sa.Port >> 8)
   659  	p[1] = byte(sa.Port)
   660  	sa.raw.Scope_id = sa.ZoneId
   661  	for i := 0; i < len(sa.Addr); i++ {
   662  		sa.raw.Addr[i] = sa.Addr[i]
   663  	}
   664  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
   665  }
   666  
   667  type SockaddrUnix struct {
   668  	Name string
   669  }
   670  
   671  func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, int32, error) {
   672  	// TODO(brainman): implement SockaddrUnix.sockaddr()
   673  	return nil, 0, EWINDOWS
   674  }
   675  
   676  func (rsa *RawSockaddrAny) Sockaddr() (Sockaddr, error) {
   677  	switch rsa.Addr.Family {
   678  	case AF_UNIX:
   679  		return nil, EWINDOWS
   680  
   681  	case AF_INET:
   682  		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
   683  		sa := new(SockaddrInet4)
   684  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   685  		sa.Port = int(p[0])<<8 + int(p[1])
   686  		for i := 0; i < len(sa.Addr); i++ {
   687  			sa.Addr[i] = pp.Addr[i]
   688  		}
   689  		return sa, nil
   690  
   691  	case AF_INET6:
   692  		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
   693  		sa := new(SockaddrInet6)
   694  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   695  		sa.Port = int(p[0])<<8 + int(p[1])
   696  		sa.ZoneId = pp.Scope_id
   697  		for i := 0; i < len(sa.Addr); i++ {
   698  			sa.Addr[i] = pp.Addr[i]
   699  		}
   700  		return sa, nil
   701  	}
   702  	return nil, EAFNOSUPPORT
   703  }
   704  
   705  func Socket(domain, typ, proto int) (fd Handle, err error) {
   706  	if domain == AF_INET6 && SocketDisableIPv6 {
   707  		return InvalidHandle, EAFNOSUPPORT
   708  	}
   709  	return socket(int32(domain), int32(typ), int32(proto))
   710  }
   711  
   712  func SetsockoptInt(fd Handle, level, opt int, value int) (err error) {
   713  	v := int32(value)
   714  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&v)), int32(unsafe.Sizeof(v)))
   715  }
   716  
   717  func Bind(fd Handle, sa Sockaddr) (err error) {
   718  	ptr, n, err := sa.sockaddr()
   719  	if err != nil {
   720  		return err
   721  	}
   722  	return bind(fd, ptr, n)
   723  }
   724  
   725  func Connect(fd Handle, sa Sockaddr) (err error) {
   726  	ptr, n, err := sa.sockaddr()
   727  	if err != nil {
   728  		return err
   729  	}
   730  	return connect(fd, ptr, n)
   731  }
   732  
   733  func Getsockname(fd Handle) (sa Sockaddr, err error) {
   734  	var rsa RawSockaddrAny
   735  	l := int32(unsafe.Sizeof(rsa))
   736  	if err = getsockname(fd, &rsa, &l); err != nil {
   737  		return
   738  	}
   739  	return rsa.Sockaddr()
   740  }
   741  
   742  func Getpeername(fd Handle) (sa Sockaddr, err error) {
   743  	var rsa RawSockaddrAny
   744  	l := int32(unsafe.Sizeof(rsa))
   745  	if err = getpeername(fd, &rsa, &l); err != nil {
   746  		return
   747  	}
   748  	return rsa.Sockaddr()
   749  }
   750  
   751  func Listen(s Handle, n int) (err error) {
   752  	return listen(s, int32(n))
   753  }
   754  
   755  func Shutdown(fd Handle, how int) (err error) {
   756  	return shutdown(fd, int32(how))
   757  }
   758  
   759  func WSASendto(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to Sockaddr, overlapped *Overlapped, croutine *byte) (err error) {
   760  	rsa, l, err := to.sockaddr()
   761  	if err != nil {
   762  		return err
   763  	}
   764  	return WSASendTo(s, bufs, bufcnt, sent, flags, (*RawSockaddrAny)(unsafe.Pointer(rsa)), l, overlapped, croutine)
   765  }
   766  
   767  func LoadGetAddrInfo() error {
   768  	return procGetAddrInfoW.Find()
   769  }
   770  
   771  var connectExFunc struct {
   772  	once sync.Once
   773  	addr uintptr
   774  	err  error
   775  }
   776  
   777  func LoadConnectEx() error {
   778  	connectExFunc.once.Do(func() {
   779  		var s Handle
   780  		s, connectExFunc.err = Socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)
   781  		if connectExFunc.err != nil {
   782  			return
   783  		}
   784  		defer CloseHandle(s)
   785  		var n uint32
   786  		connectExFunc.err = WSAIoctl(s,
   787  			SIO_GET_EXTENSION_FUNCTION_POINTER,
   788  			(*byte)(unsafe.Pointer(&WSAID_CONNECTEX)),
   789  			uint32(unsafe.Sizeof(WSAID_CONNECTEX)),
   790  			(*byte)(unsafe.Pointer(&connectExFunc.addr)),
   791  			uint32(unsafe.Sizeof(connectExFunc.addr)),
   792  			&n, nil, 0)
   793  	})
   794  	return connectExFunc.err
   795  }
   796  
   797  func connectEx(s Handle, name unsafe.Pointer, namelen int32, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) (err error) {
   798  	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)
   799  	if r1 == 0 {
   800  		if e1 != 0 {
   801  			err = error(e1)
   802  		} else {
   803  			err = EINVAL
   804  		}
   805  	}
   806  	return
   807  }
   808  
   809  func ConnectEx(fd Handle, sa Sockaddr, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) error {
   810  	err := LoadConnectEx()
   811  	if err != nil {
   812  		return errorspkg.New("failed to find ConnectEx: " + err.Error())
   813  	}
   814  	ptr, n, err := sa.sockaddr()
   815  	if err != nil {
   816  		return err
   817  	}
   818  	return connectEx(fd, ptr, n, sendBuf, sendDataLen, bytesSent, overlapped)
   819  }
   820  
   821  // Invented structures to support what package os expects.
   822  type Rusage struct {
   823  	CreationTime Filetime
   824  	ExitTime     Filetime
   825  	KernelTime   Filetime
   826  	UserTime     Filetime
   827  }
   828  
   829  type WaitStatus struct {
   830  	ExitCode uint32
   831  }
   832  
   833  func (w WaitStatus) Exited() bool { return true }
   834  
   835  func (w WaitStatus) ExitStatus() int { return int(w.ExitCode) }
   836  
   837  func (w WaitStatus) Signal() Signal { return -1 }
   838  
   839  func (w WaitStatus) CoreDump() bool { return false }
   840  
   841  func (w WaitStatus) Stopped() bool { return false }
   842  
   843  func (w WaitStatus) Continued() bool { return false }
   844  
   845  func (w WaitStatus) StopSignal() Signal { return -1 }
   846  
   847  func (w WaitStatus) Signaled() bool { return false }
   848  
   849  func (w WaitStatus) TrapCause() int { return -1 }
   850  
   851  // Timespec is an invented structure on Windows, but here for
   852  // consistency with the syscall package for other operating systems.
   853  type Timespec struct {
   854  	Sec  int64
   855  	Nsec int64
   856  }
   857  
   858  func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
   859  
   860  func NsecToTimespec(nsec int64) (ts Timespec) {
   861  	ts.Sec = nsec / 1e9
   862  	ts.Nsec = nsec % 1e9
   863  	return
   864  }
   865  
   866  // TODO(brainman): fix all needed for net
   867  
   868  func Accept(fd Handle) (nfd Handle, sa Sockaddr, err error) { return 0, nil, EWINDOWS }
   869  func Recvfrom(fd Handle, p []byte, flags int) (n int, from Sockaddr, err error) {
   870  	return 0, nil, EWINDOWS
   871  }
   872  func Sendto(fd Handle, p []byte, flags int, to Sockaddr) (err error)       { return EWINDOWS }
   873  func SetsockoptTimeval(fd Handle, level, opt int, tv *Timeval) (err error) { return EWINDOWS }
   874  
   875  // The Linger struct is wrong but we only noticed after Go 1.
   876  // sysLinger is the real system call structure.
   877  
   878  // BUG(brainman): The definition of Linger is not appropriate for direct use
   879  // with Setsockopt and Getsockopt.
   880  // Use SetsockoptLinger instead.
   881  
   882  type Linger struct {
   883  	Onoff  int32
   884  	Linger int32
   885  }
   886  
   887  type sysLinger struct {
   888  	Onoff  uint16
   889  	Linger uint16
   890  }
   891  
   892  type IPMreq struct {
   893  	Multiaddr [4]byte /* in_addr */
   894  	Interface [4]byte /* in_addr */
   895  }
   896  
   897  type IPv6Mreq struct {
   898  	Multiaddr [16]byte /* in6_addr */
   899  	Interface uint32
   900  }
   901  
   902  func GetsockoptInt(fd Handle, level, opt int) (int, error) { return -1, EWINDOWS }
   903  
   904  func SetsockoptLinger(fd Handle, level, opt int, l *Linger) (err error) {
   905  	sys := sysLinger{Onoff: uint16(l.Onoff), Linger: uint16(l.Linger)}
   906  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&sys)), int32(unsafe.Sizeof(sys)))
   907  }
   908  
   909  func SetsockoptInet4Addr(fd Handle, level, opt int, value [4]byte) (err error) {
   910  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&value[0])), 4)
   911  }
   912  func SetsockoptIPMreq(fd Handle, level, opt int, mreq *IPMreq) (err error) {
   913  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(mreq)), int32(unsafe.Sizeof(*mreq)))
   914  }
   915  func SetsockoptIPv6Mreq(fd Handle, level, opt int, mreq *IPv6Mreq) (err error) { return EWINDOWS }
   916  
   917  func Getpid() (pid int) { return int(getCurrentProcessId()) }
   918  
   919  func FindFirstFile(name *uint16, data *Win32finddata) (handle Handle, err error) {
   920  	// NOTE(rsc): The Win32finddata struct is wrong for the system call:
   921  	// the two paths are each one uint16 short. Use the correct struct,
   922  	// a win32finddata1, and then copy the results out.
   923  	// There is no loss of expressivity here, because the final
   924  	// uint16, if it is used, is supposed to be a NUL, and Go doesn't need that.
   925  	// For Go 1.1, we might avoid the allocation of win32finddata1 here
   926  	// by adding a final Bug [2]uint16 field to the struct and then
   927  	// adjusting the fields in the result directly.
   928  	var data1 win32finddata1
   929  	handle, err = findFirstFile1(name, &data1)
   930  	if err == nil {
   931  		copyFindData(data, &data1)
   932  	}
   933  	return
   934  }
   935  
   936  func FindNextFile(handle Handle, data *Win32finddata) (err error) {
   937  	var data1 win32finddata1
   938  	err = findNextFile1(handle, &data1)
   939  	if err == nil {
   940  		copyFindData(data, &data1)
   941  	}
   942  	return
   943  }
   944  
   945  func getProcessEntry(pid int) (*ProcessEntry32, error) {
   946  	snapshot, err := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)
   947  	if err != nil {
   948  		return nil, err
   949  	}
   950  	defer CloseHandle(snapshot)
   951  	var procEntry ProcessEntry32
   952  	procEntry.Size = uint32(unsafe.Sizeof(procEntry))
   953  	if err = Process32First(snapshot, &procEntry); err != nil {
   954  		return nil, err
   955  	}
   956  	for {
   957  		if procEntry.ProcessID == uint32(pid) {
   958  			return &procEntry, nil
   959  		}
   960  		err = Process32Next(snapshot, &procEntry)
   961  		if err != nil {
   962  			return nil, err
   963  		}
   964  	}
   965  }
   966  
   967  func Getppid() (ppid int) {
   968  	pe, err := getProcessEntry(Getpid())
   969  	if err != nil {
   970  		return -1
   971  	}
   972  	return int(pe.ParentProcessID)
   973  }
   974  
   975  // TODO(brainman): fix all needed for os
   976  func Fchdir(fd Handle) (err error)             { return EWINDOWS }
   977  func Link(oldpath, newpath string) (err error) { return EWINDOWS }
   978  func Symlink(path, link string) (err error)    { return EWINDOWS }
   979  
   980  func Fchmod(fd Handle, mode uint32) (err error)        { return EWINDOWS }
   981  func Chown(path string, uid int, gid int) (err error)  { return EWINDOWS }
   982  func Lchown(path string, uid int, gid int) (err error) { return EWINDOWS }
   983  func Fchown(fd Handle, uid int, gid int) (err error)   { return EWINDOWS }
   984  
   985  func Getuid() (uid int)                  { return -1 }
   986  func Geteuid() (euid int)                { return -1 }
   987  func Getgid() (gid int)                  { return -1 }
   988  func Getegid() (egid int)                { return -1 }
   989  func Getgroups() (gids []int, err error) { return nil, EWINDOWS }
   990  
   991  type Signal int
   992  
   993  func (s Signal) Signal() {}
   994  
   995  func (s Signal) String() string {
   996  	if 0 <= s && int(s) < len(signals) {
   997  		str := signals[s]
   998  		if str != "" {
   999  			return str
  1000  		}
  1001  	}
  1002  	return "signal " + itoa(int(s))
  1003  }
  1004  
  1005  func LoadCreateSymbolicLink() error {
  1006  	return procCreateSymbolicLinkW.Find()
  1007  }
  1008  
  1009  // Readlink returns the destination of the named symbolic link.
  1010  func Readlink(path string, buf []byte) (n int, err error) {
  1011  	fd, err := CreateFile(StringToUTF16Ptr(path), GENERIC_READ, 0, nil, OPEN_EXISTING,
  1012  		FILE_FLAG_OPEN_REPARSE_POINT|FILE_FLAG_BACKUP_SEMANTICS, 0)
  1013  	if err != nil {
  1014  		return -1, err
  1015  	}
  1016  	defer CloseHandle(fd)
  1017  
  1018  	rdbbuf := make([]byte, MAXIMUM_REPARSE_DATA_BUFFER_SIZE)
  1019  	var bytesReturned uint32
  1020  	err = DeviceIoControl(fd, FSCTL_GET_REPARSE_POINT, nil, 0, &rdbbuf[0], uint32(len(rdbbuf)), &bytesReturned, nil)
  1021  	if err != nil {
  1022  		return -1, err
  1023  	}
  1024  
  1025  	rdb := (*reparseDataBuffer)(unsafe.Pointer(&rdbbuf[0]))
  1026  	var s string
  1027  	switch rdb.ReparseTag {
  1028  	case IO_REPARSE_TAG_SYMLINK:
  1029  		data := (*symbolicLinkReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
  1030  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
  1031  		s = UTF16ToString(p[data.PrintNameOffset/2 : (data.PrintNameLength-data.PrintNameOffset)/2])
  1032  	case _IO_REPARSE_TAG_MOUNT_POINT:
  1033  		data := (*mountPointReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
  1034  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
  1035  		s = UTF16ToString(p[data.PrintNameOffset/2 : (data.PrintNameLength-data.PrintNameOffset)/2])
  1036  	default:
  1037  		// the path is not a symlink or junction but another type of reparse
  1038  		// point
  1039  		return -1, ENOENT
  1040  	}
  1041  	n = copy(buf, []byte(s))
  1042  
  1043  	return n, nil
  1044  }