case *syscall.SockaddrInet6:
		return &IPAddr{IP: sa.Addr[0:], Zone: zoneCache.name(int(sa.ZoneId))}
	}
	return nil
}

func (a *IPAddr) family() int {
	if a == nil || len(a.IP) <= IPv4len {
		return syscall.AF_INET
	}
	if a.IP.To4() != nil {
		return syscall.AF_INET
	}
	return syscall.AF_INET6
}

func (a *IPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
	if a == nil {

				return nil, errors.New("cannot parse network mask for interface: " + status)
			}
			var mask IPMask
			if ip.To4() != nil { // IPv4 or IPv6 IPv4-mapped address
				mask = CIDRMask(pfxlen-8*len(v4InV6Prefix), 8*IPv4len)
			}
			if ip.To16() != nil && ip.To4() == nil { // IPv6 address
				mask = CIDRMask(pfxlen, 8*IPv6len)
			}

			addrs = append(addrs, &IPNet{IP: ip, Mask: mask})
		}
	}

	return addrs, nil

	case *syscall.SockaddrInet6:
		return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneCache.name(int(sa.ZoneId))}
	}
	return nil
}

func (a *UDPAddr) family() int {
	if a == nil || len(a.IP) <= IPv4len {
		return syscall.AF_INET
	}
	if a.IP.To4() != nil {
		return syscall.AF_INET
	}
	return syscall.AF_INET6
}

func (a *UDPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
	if a == nil {

	case *syscall.SockaddrInet6:
		return &TCPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneCache.name(int(sa.ZoneId))}
	}
	return nil
}

func (a *TCPAddr) family() int {
	if a == nil || len(a.IP) <= IPv4len {
		return syscall.AF_INET
	}
	if a.IP.To4() != nil {
		return syscall.AF_INET
	}
	return syscall.AF_INET6
}

func (a *TCPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
	if a == nil {