Re: if_nameindex/getifaddrs and dhcpcd issue

[Natanael Copa <ncopa@alpinelinux.org>]

On Tue, 8 Apr 2014 11:07:47 +0100
Justin Cormack <justin@specialbusservice.com> wrote:

> On Tue, Apr 8, 2014 at 10:11 AM, Natanael Copa <ncopa@alpinelinux.org> wrote:
> > (snip)
> 
> I am not sure that it is appropriate that a netlink implementation,
> which is the only way to do the enumeration correctly in the potential
> absense of /proc, should go into Musl. I would be more inclined to
> implement a new library to do netlink stuff that provides compatible
> interfaces (you could use libnetlink too). The glibc implementation is
> 723 lines of code, and it is probably hard to make the implementation
> a lot smaller, but you could make a full netlink library in not much
> more as it is complicated but uniform (I wrote a partly complete one
> in 1000 lines of Lua).

I believe it can be better done than what glibc does.

> However I can see no reason why dhcp on a specified interface needs to
> enumerate interfaces at all, 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.

dhcpcd != dhcp.

In any case, i think if_nameindex should return a list of all
interfaces, not only those who have a configured ipv4 address.

I also think that the way getifaddrs uses /proc for ipv6 is ugly so I'd
say that both getifaddrs and if_nameindex would be better off with
netlink.

-nc