return nil, errMissingAddress
		}
	case "listen":
	default:
		return nil, errors.New("unknown mode: " + mode)
	}

	fd, err := socket(ctx, net, syscall.AF_UNIX, sotype, 0, false, laddr, raddr, ctxCtrlFn)
	if err != nil {
		return nil, err
	}
	return fd, nil
}

func sockaddrToUnix(sa syscall.Sockaddr) Addr {
	if s, ok := sa.(*syscall.SockaddrUnix); ok {

	buf := make([]syscall.WSAProtocolInfo, n)
	n, err := syscall.WSAEnumProtocols(nil, &buf[0], &size)
	if err != nil {
		return false
	}
	for i := int32(0); i < n; i++ {
		if buf[i].AddressFamily == syscall.AF_UNIX {
			return true
		}
	}
	return false

	rsa, _ := syscall.Getpeername(s)
	switch lsa.(type) {
	case *syscall.SockaddrInet4:
		family = syscall.AF_INET
	case *syscall.SockaddrInet6:
		family = syscall.AF_INET6
	case *syscall.SockaddrUnix:
		family = syscall.AF_UNIX
	default:
		poll.CloseFunc(s)
		return nil, syscall.EPROTONOSUPPORT
	}
	fd, err := newFD(s, family, sotype, "")
	if err != nil {
		poll.CloseFunc(s)
		return nil, err
	}
	laddr := fd.addrFunc()(lsa)

	if err != nil {
		t.Fatal(err)
	}
	defer c.Close()

	off := make(chan bool)
	data := [5]byte{1, 2, 3, 4, 5}
	go func() {
		defer func() { off <- true }()
		s, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_DGRAM, 0)
		if err != nil {
			t.Error(err)
			return
		}
		defer syscall.Close(s)
		rsa := &syscall.SockaddrUnix{Name: addr}
		if err := syscall.Sendto(s, data[:], 0, rsa); err != nil {

	socketDialRetryPeriod = 1 * time.Second
	// Overall timeout value to dial a Unix domain socket, including retries
	socketDialTimeout = 4 * time.Second
)

// IsUnixDomainSocket returns whether a given file is a AF_UNIX socket file
// Note that due to the retry logic inside, it could take up to 4 seconds
// to determine whether or not the file path supplied is a Unix domain socket
func IsUnixDomainSocket(filePath string) (bool, error) {