Re: [PATCH] ethtool: allow non-netadmin to query settings

[Stephen Hemminger <shemminger@vyatta.com>]

On Mon, 23 Aug 2010 22:24:38 +0100
Ben Hutchings <bhutchings@solarflare.com> wrote:

> On Mon, 2010-08-23 at 13:24 -0700, Stephen Hemminger wrote:
> > The SNMP daemon uses ethtool to determine the speed of
> > network interfaces. This fails on Debian (and probably elsewhere)
> > because for security SNMP daemon runs as non-root user (snmp).
> > 
> > Note: A similar patch was rejected previously because of a concern about
> > the possibility that on some hardware querying the ethtool settings
> > requires access to the PHY and could slow the machine down.  But the
> > security risk of requiring SNMP daemon (and related services)
> > to run as root far out weighs the risk of denial-of-service.
> [...]
> 
> Speed and duplex are now exposed through world-readable attributes in
> sysfs.  Currently this is implemented by calling the ethtool
> get_settings() operations but that could be improved on by adding speed
> and duplex fields to struct net_device or by allowing drivers to
> implement a cheaper operation that provides just this information.
> 

Changing daemon is possible, but changing every driver to do this
is not a practical option.