Re: [PATCH] udev: create empty regular files to represent net interfaces

[Matt Domsch <Matt_Domsch@Dell.com>]

On Thu, Oct 22, 2009 at 12:36:20AM -0600, dann frazier wrote:
> Here's a proof of concept to further the discussion..
> 
> The default filename uses the format:
>   /dev/netdev/by-ifindex/$ifindex
> 
> This provides the infrastructure to permit udev rules to create aliases for
> network devices using symlinks, for example:
> 
>   /dev/netdev/by-name/eth0 -> ../by-ifindex/1
>   /dev/netdev/by-biosname/LOM0 -> ../by-ifindex/3
> 
> A library (such as the proposed libnetdevname) could use this information
> to provide an alias->realname mapping for network utilities.

yes, this could work, as IFINDEX is already exported in the uevents,
and that's the primary value udev needs to set up the mapping.

While I like the little ifindex2name script you've got, I think udev
could simply call if_indextoname() to get this, and not call an
external program?  I suppose it could be a really really simple
external program too.

I'd be fine with this approach.  It has the advantages of not
requiring a kernel change at all, and not creating a whole character
device which would be useless.  And it doesn't preclude someone in the
future from creating a char device for network devices should they so
choose.

Kay, what say you as udev owner?

Thanks,
Matt

-- 
Matt Domsch
Technology Strategist, Dell Office of the CTO
linux.dell.com & www.dell.com/linux