Re: if_nameindex/getifaddrs and dhcpcd issue

[Natanael Copa <ncopa@alpinelinux.org>]

On Tue, 8 Apr 2014 11:38:41 -0400
Rich Felker <dalias@aerifal.cx> wrote:

> On Tue, Apr 08, 2014 at 03:16:10PM +0100, Justin Cormack wrote:
> > I was under the impression that the ioctl-based interface for ipv6 is
> > incomplete under Linux.
> 
> Probably "incomplete" in a sense that it can't do some special-purpose
> stuff that most users don't need.

You cannot get the configured ipv6 addresses via SIOCGIFCONF. That is
why musl needs to parse /proc for that.

ioctl-based interface for ipv4 is also "incomplete". You cannot get
anything else than the primary address so current musl getifaddrs will
not give you all configured ipv4 addresses.

> Busybox entirely avoids netlink, as
> far as I can tell,

Not entirely. the iproute implementation in bb uses netlink, but you
can of course disable that during configuration. A quick grep also
indicate that busybox ifplugd uses netlink.

> and it's perfectly acceptable for setting up ipv6,
> at least in simple setups. You don't even need busybox's iproute2
> workalikes; ifconfig and route work fine.

And if you do that, then you cannot assign more than one ip addr on
each interface. (you'll have to use alias, eth0:1 for that), but yes,
thats no longer a simple setup.

-nc