Re: if_nameindex/getifaddrs and dhcpcd issue

[Justin Cormack <justin@specialbusservice.com>]

On Tue, Apr 8, 2014 at 2:42 PM, Rich Felker <dalias@aerifal.cx> wrote:
>> and it only needs to read ipv4 addresses,
>> unless it is implementing dhcp6 too, maybe it does now. Again dhcp6
>> needs netlink, the Musl ipv6 parts for getifaddrs already use /proc
>> which is definitely unreliable for early boot config in a distro in my
>> view.
>
> In what way does dhcp6 need netlink? What's made this discussion
> difficult so far on IRC is assertions of that form (although not the
> same one) without an explanation of why it's believed to be true, so
> I'd like to keep rational discussion possible by making sure that such
> claims are backed up by explanation rather than just stated as fact.

I was under the impression that the ioctl-based interface for ipv6 is
incomplete under Linux. That does not mean anything needs to be in
libc though. ISC dhcp for v6 just calls out to ip in scripts, rather
than ifconfig that it uses for v4, so it is indirectly uses netlink,
but does not require any libc support, indeed all the C code is
portable.

Justin