I was thinking, if we're not planning on use the chardev/kernel route.  There already exists an ifindex file in /sys/class/net/XXX/ifindex.
Should udev/helper be creating links to this, or is it better to keep everything under the /dev/ tree?
Using this method would require the patch to udev to handle renaming events.

--jordan hargrave
Dell Enterprise Linux Engineering



-----Original Message-----
From: dann frazier [mailto:dannf@hp.com]
Sent: Wed 10/28/2009 10:09
To: Domsch, Matt
Cc: Kay Sievers; linux-hotplug@vger.kernel.org; K, Narendra; netdev@vger.kernel.org; Hargrave, Jordan; Rose, Charles; Ben Hutchings
Subject: Re: [PATCH] udev: create empty regular files to represent net interfaces
 
On Wed, Oct 28, 2009 at 08:03:08AM -0500, Matt Domsch wrote:

On Wed, Oct 28, 2009 at 09:23:57AM +0100, Kay Sievers wrote:

[...]

quoted

That all sounds very much like something which will hit us back some
day. I'm not sure, if udev should publish such dead text files in
/dev, it does not seem to fit the usual APIs/assumptions where /sys
and /dev match, and libudev provides access to both. It all sounds
more like a database for a possible netdevname library, which does not
need to be public in /dev, right?

Right, it doesn't need to be in /dev.  We could have udev rules that
simply call yet another program to maintain that database, in yet
another way.

Or have udev maintain them in a private directory (e.g.,
/var/lib/udev/netalias). Personally, I like the approach of having
udev manage them as files - its an abstraction our users already get,
and they don't have to learn two mechanisms when aliasing disks and
nics (SYMLINK ftw). Plus there's obviously a lot of code reuse to be
had (most of my patch was moving code into a common section).

If we want to hide the file implementation - we could invent another
udev construct that basically aliases SYMLINK (e.g. NETALIAS) that
works iff the device is a netdevice. That would let us switch out
implementations in the future, but would obviously be much more
invasive.

-- 
dann frazier