case syscall.AF_INET:
		sa, err := addrPortToSockaddrInet4(addr)
		if err != nil {
			return 0, err
		}
		return c.fd.writeToInet4(b, &sa)
	case syscall.AF_INET6:
		sa, err := addrPortToSockaddrInet6(addr)
		if err != nil {
			return 0, err
		}
		return c.fd.writeToInet6(b, &sa)
	default:
		return 0, &AddrError{Err: "invalid address family", Addr: addr.Addr().String()}
	}
}

	}
	sa := syscall.SockaddrInet4{
		Addr: addr.As4(),
		Port: int(ap.Port()),
	}
	return sa, nil
}

func addrPortToSockaddrInet6(ap netip.AddrPort) (syscall.SockaddrInet6, error) {
	// ipToSockaddrInet6 has special handling here for zero length slices.
	// We do not, because netip has no concept of a generic zero IP address.
	//