netdev - Re: Network Device Naming mechanism and policy

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 24 Mar 2009 17:21:16 +0100
From:	Patrick McHardy <kaber@...sh.net>
To:	Matt Domsch <Matt_Domsch@...l.com>
CC:	netdev@...r.kernel.org, linux-hotplug@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: Network Device Naming mechanism and policy

Matt Domsch wrote:
> 2) udev may have rules to change the device names.  This is most often
>    seen in the '70-persistent-net.rules' file.  Here we have
>    additional challenges:
> 
> ...
> 
>    c) udev may not always be able to change a device's name.  If udev
>       uses the kernel assignment namespace (ethN), then a rename of
>       eth0->eth1 may require renaming eth1->eth0 (or something else).
>       Udev operates on a single device instance at a time, it becomes
>       difficult to switch names around for multiple devices, within
>       the single namespace.

I would classify this as a bug, especially the fact that udev doesn't
undo a failed rename, so you end up with ethX_rename. Virtual devices
using the same MAC address trigger this reliably unless you add
exceptions to the udev rules.

You state that it only operates on one device at a time. If that is
correct, I'm not sure why the _rename suffix is used at all instead
of simply trying to assign the final name, which would avoid this
problem.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html