//go:linkname WSASendtoInet6 syscall.wsaSendtoInet6
//go:noescape
func WSASendtoInet6(s syscall.Handle, bufs *syscall.WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *syscall.SockaddrInet6, overlapped *syscall.Overlapped, croutine *byte) (err error)

const (

	r1, _, e1 := Syscall9(procDeviceIoControl.Addr(), 8, uintptr(handle), uintptr(ioControlCode), uintptr(unsafe.Pointer(inBuffer)), uintptr(inBufferSize), uintptr(unsafe.Pointer(outBuffer)), uintptr(outBufferSize), uintptr(unsafe.Pointer(bytesReturned)), uintptr(unsafe.Pointer(overlapped)), 0)
	if r1 == 0 {
		err = errnoErr(e1)
	}
	return
}

	// method to return a handle that uses ordinary synchronous I/O.”
	// However, LockFileEx still requires an OVERLAPPED structure,
	// which contains the file offset of the beginning of the lock range.
	// We want to lock the entire file, so we leave the offset as zero.
	ol := new(syscall.Overlapped)

	err := windows.LockFileEx(syscall.Handle(f.Fd()), uint32(lt), reserved, allBytes, allBytes, ol)
	if err != nil {

}

//sys LockFileEx(file syscall.Handle, flags uint32, reserved uint32, bytesLow uint32, bytesHigh uint32, overlapped *syscall.Overlapped) (err error) = kernel32.LockFileEx
//sys UnlockFileEx(file syscall.Handle, reserved uint32, bytesLow uint32, bytesHigh uint32, overlapped *syscall.Overlapped) (err error) = kernel32.UnlockFileEx

const (
	LOCKFILE_FAIL_IMMEDIATELY = 0x00000001
	LOCKFILE_EXCLUSIVE_LOCK   = 0x00000002
)

//sys	getQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uintptr, overlapped **Overlapped, timeout uint32) (err error) = GetQueuedCompletionStatus
//sys	postQueuedCompletionStatus(cphandle Handle, qty uint32, key uintptr, overlapped *Overlapped) (err error) = PostQueuedCompletionStatus
//sys	CancelIo(s Handle) (err error)
//sys	CancelIoEx(s Handle, o *Overlapped) (err error)

func (fd *FD) WSAIoctl(iocc uint32, inbuf *byte, cbif uint32, outbuf *byte, cbob uint32, cbbr *uint32, overlapped *syscall.Overlapped, completionRoutine uintptr) error {
	if err := fd.incref(); err != nil {
		return err
	}
	defer fd.decref()
	return syscall.WSAIoctl(fd.Sysfd, iocc, inbuf, cbif, outbuf, cbob, cbbr, overlapped, completionRoutine)

//sys	readFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error) = ReadFile
//sys	writeFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error) = WriteFile
//sys	GetOverlappedResult(handle Handle, overlapped *Overlapped, done *uint32, wait bool) (err error)

	const SIO_TCP_INFO = syscall.IOC_INOUT | syscall.IOC_VENDOR | 39
	inbuf := uint32(0)
	var outbuf _TCP_INFO_v0
	cbbr := uint32(0)

	var ov syscall.Overlapped
	// Create an event so that we can efficiently wait for completion
	// of a requested overlapped I/O operation.
	ov.HEvent, _ = windows.CreateEvent(nil, 0, 0, nil)
	if ov.HEvent == 0 {
		t.Fatalf("could not create the event!")
	}

func (sw *Switch) AcceptEx(ls syscall.Handle, as syscall.Handle, b *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, rcvd *uint32, overlapped *syscall.Overlapped) error {
	so := sw.sockso(ls)
	if so == nil {
		return syscall.AcceptEx(ls, as, b, rxdatalen, laddrlen, raddrlen, rcvd, overlapped)
	}
	sw.fmu.RLock()
	f, _ := sw.fltab[FilterAccept]
	sw.fmu.RUnlock()

	af, err := f.apply(so)
	if err != nil {

var AcceptFunc func(syscall.Handle, syscall.Handle, *byte, uint32, uint32, uint32, *uint32, *syscall.Overlapped) error = syscall.AcceptEx

// ConnectExFunc is used to hook the ConnectEx call.