}
	return nil
}

// CloseWrite shuts down the writing side of the TCP connection.
// Most callers should just use Close.
func (c *TCPConn) CloseWrite() error {
	if !c.ok() {
		return syscall.EINVAL
	}
	if err := c.fd.closeWrite(); err != nil {
		return &OpError{Op: "close", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}
	return nil
}

//sys	Chroot(path string) (err error)
//sys	Close(fd int) (err error)
//sys	closedir(dir uintptr) (err error)
//sys	Dup(fd int) (nfd int, err error)
//sys	Dup2(from int, to int) (err error)
//sys	Exchangedata(path1 string, path2 string, options int) (err error)
//sys	Fchdir(fd int) (err error)
//sys	Fchflags(fd int, flags int) (err error)
//sys	Fchmod(fd int, mode uint32) (err error)
//sys	Fchown(fd int, uid int, gid int) (err error)

type fakeNs struct {
	closed *atomic.Bool
	fd     uintptr
	inode  uint64
}

func newFakeNs(fd uintptr) *fakeNs {
	// the fake inode is the fd! magic.
	return &fakeNs{closed: &atomic.Bool{}, fd: fd, inode: uint64(fd)}
}

func newFakeNsInode(fd uintptr, inode uint64) *fakeNs {
	return &fakeNs{closed: &atomic.Bool{}, fd: fd, inode: inode}
}

// Fd returns the file descriptor
func (f *fakeNs) Fd() uintptr {

	}
	sa, err := addr.sockaddr(c.fd.family)
	if err != nil {
		return 0, err
	}
	return c.fd.writeTo(b, sa)
}

func (c *IPConn) writeMsg(b, oob []byte, addr *IPAddr) (n, oobn int, err error) {
	if c.fd.isConnected {
		return 0, 0, ErrWriteToConnected
	}
	if addr == nil {
		return 0, 0, errMissingAddress
	}
	sa, err := addr.sockaddr(c.fd.family)
	if err != nil {
		return 0, 0, err
	}

		// reissued the fd in a later call to open(2), leading
		// to crashes being written to the wrong file.
		//
		// So, we duplicate the fd to obtain a private one
		// that cannot be closed by the user.
		// This also alleviates us from concerns about the
		// lifetime and finalization of f.
		// (DupCloseOnExec returns an fd, not a *File, so
		// there is no finalizer, and we are responsible for

		}
	}

	// Pass 1: look for fd[i] < i and move those up above len(fd)
	// so that pass 2 won't stomp on an fd it needs later.
	if pipe < nextfd {
		r1, _, _ = RawSyscall(SYS_DUP, uintptr(pipe), uintptr(nextfd), 0)
		if int32(r1) == -1 {
			goto childerror
		}
		pipe = nextfd
		nextfd++
	}
	for i = 0; i < len(fd); i++ {
		if fd[i] >= 0 && fd[i] < i {
			if nextfd == pipe { // don't stomp on pipe

		remain, r = lr.N, lr.R
		if remain <= 0 {
			return 0, nil, true
		}
	}

	var s *netFD
	switch v := r.(type) {
	case *TCPConn:
		s = v.fd
	case tcpConnWithoutWriteTo:
		s = v.fd
	case *UnixConn:
		if v.fd.net != "unix" {
			return 0, nil, false
		}
		s = v.fd
	default:
		return 0, nil, false
	}

	written, handled, err = pollSplice(&c.pfd, &s.pfd, remain)
	if lr != nil {
		lr.N -= written
	}

	"time"
)

func getCurrentKeepAliveSettings(fd fdType) (cfg KeepAliveConfig, err error) {
	tcpKeepAlive, err := syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_KEEPALIVE)
	if err != nil {
		return
	}
	tcpKeepAliveIdle, err := syscall.GetsockoptInt(fd, syscall.IPPROTO_TCP, syscall_TCP_KEEPIDLE)
	if err != nil {
		return
	}
	tcpKeepAliveInterval, err := syscall.GetsockoptInt(fd, syscall.IPPROTO_TCP, syscall_TCP_KEEPINTVL)

	if err != nil {
		return nil, err
	}
	return newTCPConn(fd, ln.lc.KeepAlive, ln.lc.KeepAliveConfig, testPreHookSetKeepAlive, testHookSetKeepAlive), nil
}

func (ln *TCPListener) close() error {
	if err := ln.fd.pfd.Close(); err != nil {
		return err
	}
	if _, err := ln.fd.ctl.WriteString("hangup"); err != nil {
		ln.fd.ctl.Close()
		return err
	}
	if err := ln.fd.ctl.Close(); err != nil {
		return err
	}

	runtime.KeepAlive(fd)
	return wrapSyscallError("setsockopt", err)
}

func setKeepAliveCount(fd *netFD, n int) error {
	if !unix.SupportTCPKeepAliveIdleIntvlCNT() {
		return syscall.EPROTOTYPE
	}

	if n == 0 {
		n = defaultTCPKeepAliveCount
	} else if n < 0 {
		return nil
	}
	err := fd.pfd.SetsockoptInt(syscall.IPPROTO_TCP, sysTCP_KEEPCNT, n)
	runtime.KeepAlive(fd)