[PATCH] Allow compile without IPv6.

[Marcel Holtmann]

Hi Gustavo,

> >> I think new projects from 2010 should not have ipv4-only. This time
> >> should be over, finally. And people should get used to see ipv6
> >> everywhere, and we should try to break the chicken-egg thing wherever
> >> possible. :)
> >>
> >> I can see the use for a systemd without any IP networking, but
> >> compiling-out ipv6 seems like the wrong thing to me. Sure, we should
> >> make sure, that systemd handles a kernel without ipv6 gracefully, but
> >> not offer a switch to stay in the IP stone age. :)
> >
> > That means I'll have to maintain this patch outside tree forever? :-)
> 
> btw, if you allow my patch to get in, in consideration I will kindly
> create a new patch that flags if ipv6 support is present and if not
> fallback to my ipv4 code... but that also means we need review of my
> provided ipv4 code ;-)

this is the wrong approach. I agree with Kay here in that systemd needs
to handle gracefully a kernel where IPv6 is disabled, but that should be
all that it is doing.

Regards

Marcel