RE: nic enumeration

Loke, Chetan
2010-07-09T18:23:30Z

> -----Original Message-----
> From: Steve Fink [mailto:sphink@gmail.com]
> Sent: July 09, 2010 1:11 PM
> To: Loke, Chetan
> Cc: Florian Weimer; linux-net@vger.kernel.org; Matt Domsch; Michael Di
> Domenico; linux-kernel@vger.kernel.org; kay.sievers@vrfy.org
> Subject: Re: nic enumeration
>
> On Fri, Jul 9, 2010 at 9:27 AM, Loke, Chetan
<Chetan.Loke@netscout.com>
> wrote:
> > Ok, no renaming, I would like a reference. And symlink just doesn't
> work
> > w/ the udevadm trigger business. We've tried that already.
> >
> > What needs to be changed in udev etc to create a soft link? Any
place
> > where I should start digging and gotchas to lookout for?
>
> By "soft link", I assume you're talking figuratively?

Yes, I was using it loosely. symlink == I would like 'udev' to do the
linkage w/ the network-devices and create a reference to it.

> Soft (symbolic)
> links are a filesystem concept, implemented by filesystem-specific
> logic that knows how to read a filename out of an inode and restart
> lookup. In order for something similar to work for network devices,
> somebody would have had to explicitly implement similar functionality.
> (Symlinks are a big headache and source of security holes -- access
> control, loops, pointing to nonexistent files, etc. -- so there's a
> good reason to NOT have an equivalent for network devices.)
>

Huh? If the 'ethX' interface doesn't exist just don't create the 'link'.
So are you saying there are no security issues with udev-symlinks for
other subsystems? Why is renaming allowed on the network-interface then?
Isn't that a problem? I don't see the driver re-registering their RX/TX
queues with the new-if-name.

May be I'm overlooking at something really obvious. But how are people
managing [pv]drivers with multiple vNICs in their VMs if they need a
consistent naming scheme?

Regards
Chetan Loke