c.Control(func(fdPtr uintptr) {
			// got socket file descriptor to set parameters.
			fd := int(fdPtr)

			_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)

			_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)

			// Enable custom socket send/recv buffers.
			if opts.SendBufSize > 0 {
				_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_SNDBUF, opts.SendBufSize)
			}

			if opts.RecvBufSize > 0 {

	}
	return n, nil
}

func (fd *netFD) writeBuffers(buf *Buffers) (int64, error) {
	n, err := fd.pfd.Writev((*[][]byte)(buf))
	runtime.KeepAlive(fd)
	return n, wrapSyscallError("wsasend", err)
}

func (fd *netFD) accept() (*netFD, error) {
	s, rawsa, rsan, errcall, err := fd.pfd.Accept(func() (syscall.Handle, error) {
		return sysSocket(fd.family, fd.sotype, 0)
	})

	if err != nil {
		if errcall != "" {

//sys	Fchown(fd int, uid int, gid int) (err error)
//sys	Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
//sys	Fdatasync(fd int) (err error)
//sys	Flock(fd int, how int) (err error)
//sys	Fpathconf(fd int, name int) (val int, err error)
//sys	Fstat(fd int, stat *Stat_t) (err error)
//sys	Fstatat(fd int, path string, stat *Stat_t, flags int) (err error)
//sys	Fstatvfs(fd int, vfsstat *Statvfs_t) (err error)

package syscall

func Socket(proto, sotype, unused int) (fd int, err error) {
	return 0, ENOSYS
}

func Bind(fd int, sa Sockaddr) error {
	return ENOSYS
}

func StopIO(fd int) error {
	return ENOSYS
}

func Listen(fd int, backlog int) error {
	return ENOSYS
}

func Accept(fd int) (newfd int, sa Sockaddr, err error) {
	return 0, nil, ENOSYS
}

func Connect(fd int, sa Sockaddr) error {
	return ENOSYS
}

	return ioctlPtr(fd, req, unsafe.Pointer(value))
}

// IoctlSetTermios performs an ioctl on fd with a *Termios.
//
// The req value will usually be TCSETA or TIOCSETA.
func IoctlSetTermios(fd int, req int, value *Termios) error {
	// TODO: if we get the chance, remove the req parameter.
	return ioctlPtr(fd, req, unsafe.Pointer(value))
}

// IoctlGetInt performs an ioctl operation which gets an integer value

	return ioctlPtr(fd, req, unsafe.Pointer(value))
}

// IoctlSetTermios performs an ioctl on fd with a *Termios.
//
// The req value will usually be TCSETA or TIOCSETA.
func IoctlSetTermios(fd int, req uint, value *Termios) error {
	// TODO: if we get the chance, remove the req parameter.
	return ioctlPtr(fd, req, unsafe.Pointer(value))
}

// IoctlGetInt performs an ioctl operation which gets an integer value

//sysnb socketpair(domain int, typ int, proto int, fd *[2]int32) (err error)

func GetsockoptByte(fd, level, opt int) (value byte, err error) {
	var n byte
	vallen := _Socklen(1)
	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
	return n, err
}

func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
	vallen := _Socklen(4)
	err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)

	if !c.ok() {
		return 0, syscall.EINVAL
	}
	n, err := c.fd.writeBuffers(v)
	if err != nil {
		return n, &OpError{Op: "writev", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}
	return n, nil
}

func (fd *netFD) writeBuffers(v *Buffers) (n int64, err error) {
	n, err = fd.pfd.Writev((*[][]byte)(v))
	runtime.KeepAlive(fd)
	return n, wrapSyscallError("writev", err)

	"syscall"
	"testing"
	"unsafe"
)

type loggedFD struct {
	Net string
	FD  *poll.FD
	Err error
}

var (
	logMu     sync.Mutex
	loggedFDs map[syscall.Handle]*loggedFD
)

func logFD(net string, fd *poll.FD, err error) {
	logMu.Lock()
	defer logMu.Unlock()

	loggedFDs[fd.Sysfd] = &loggedFD{
		Net: net,
		FD:  fd,
		Err: err,
	}
}

func init() {

		return nil, syscall.EINVAL
	}
	return newRawConn(c.fd), nil
}

// ReadFromIP acts like ReadFrom but returns an IPAddr.
func (c *IPConn) ReadFromIP(b []byte) (int, *IPAddr, error) {
	if !c.ok() {
		return 0, nil, syscall.EINVAL
	}
	n, addr, err := c.readFrom(b)
	if err != nil {
		err = &OpError{Op: "read", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}
	return n, addr, err
}