ip = addr.IP
		wildcard = addr.isWildcard()
	}

	// Test wildcard IP addresses.
	if wildcard && !testenv.HasExternalNetwork() {
		return false
	}

	// Test functionality of IPv4 communication using AF_INET and
	// IPv6 communication using AF_INET6 sockets.
	if !supportsIPv4() && ip.To4() != nil {
		return false
	}
	if !supportsIPv6() && ip.To16() != nil && ip.To4() == nil {
		return false
	}

	return &realDeps{}
}

type realDeps struct{}

func (m *realDeps) ipsetIPHashCreate(name string, v6 bool) error {
	var family uint8

	if v6 {
		family = unix.AF_INET6
	} else {
		family = unix.AF_INET
	}
	err := netlink.IpsetCreate(name, "hash:ip", netlink.IpsetCreateOptions{Comments: true, Replace: true, Family: family})
	if ipsetErr, ok := err.(nl.IPSetError); ok && ipsetErr == nl.IPSET_ERR_EXIST {
		return nil
	}

		fd.Close()
		return nil, err
	}
	return fd, nil
}

func validateResolvedAddr(net string, family int, sa sockaddr) error {
	validateIP := func(ip IP) error {
		switch family {
		case syscall.AF_INET:
			if len(ip) != 4 {
				return &AddrError{
					Err:  "non-IPv4 address",
					Addr: ip.String(),
				}
			}
		case syscall.AF_INET6:
			if len(ip) != 16 {
				return &AddrError{

	port int
}

func NewDelayedListener() (*DelayedListener, error) {
	d := &DelayedListener{}
	addr := &syscall.SockaddrInet4{
		Port: 0,
		Addr: [4]byte{0, 0, 0, 0},
	}
	s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_STREAM, syscall.IPPROTO_IP)
	if err != nil {
		return nil, err
	}
	d.fd = s
	if err := syscall.Bind(s, addr); err != nil {
		return nil, err
	}
	sa, err := syscall.Getsockname(s)
	if err != nil {

func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
	if sa.Port < 0 || sa.Port > 0xFFFF {
		return nil, 0, EINVAL
	}
	sa.raw.Len = SizeofSockaddrInet4
	sa.raw.Family = AF_INET
	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
	p[0] = byte(sa.Port >> 8)
	p[1] = byte(sa.Port)
	sa.raw.Addr = sa.Addr
	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
}

			ipPointToPoint = true
			break
		}
	}
	for _, a := range attrs {
		if ipPointToPoint && a.Attr.Type == syscall.IFA_ADDRESS {
			continue
		}
		switch ifam.Family {
		case syscall.AF_INET:
			return &IPNet{IP: IPv4(a.Value[0], a.Value[1], a.Value[2], a.Value[3]), Mask: CIDRMask(int(ifam.Prefixlen), 8*IPv4len)}
		case syscall.AF_INET6:

func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
	if sa.Port < 0 || sa.Port > 0xFFFF {
		return nil, 0, EINVAL
	}
	sa.raw.Len = SizeofSockaddrInet4
	sa.raw.Family = AF_INET
	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
	p[0] = byte(sa.Port >> 8)
	p[1] = byte(sa.Port)
	sa.raw.Addr = sa.Addr
	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
}

}

func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
	if sa.Port < 0 || sa.Port > 0xFFFF {
		return nil, 0, EINVAL
	}
	sa.raw.Family = AF_INET
	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
	p[0] = byte(sa.Port >> 8)
	p[1] = byte(sa.Port)
	sa.raw.Addr = sa.Addr
	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet4, nil
}

		return 0, nil, err
	}
	return nfd, sa, nil
}

func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
	if sa.Port < 0 || sa.Port > 0xFFFF {
		return nil, 0, EINVAL
	}
	sa.raw.Family = AF_INET
	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
	p[0] = byte(sa.Port >> 8)
	p[1] = byte(sa.Port)
	sa.raw.Addr = sa.Addr
	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet4, nil
}

func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
	if sa.Port < 0 || sa.Port > 0xFFFF {
		return nil, 0, EINVAL
	}
	sa.raw.Family = AF_INET
	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
	p[0] = byte(sa.Port >> 8)
	p[1] = byte(sa.Port)
	sa.raw.Addr = sa.Addr
	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet4, nil
}