FreeBSD and Nagios - permissions

[Mel]

On Thursday 16 October 2008 22:07:43 Per olof Ljungmark wrote:
> Per olof Ljungmark wrote:
> > Daniel Bye wrote:
> >> On Thu, Oct 16, 2008 at 12:05:01PM +0100, Daniel Bye wrote:
> >>> It is possible to configure sudo to run only exactly the required
> >>> command
> >>> (including arguments) precisely to guard against this type of abuse -
> >>> I use it extensively in my own nagios setup.
> >>>
> >>> This Cmnd_Alias in sudoers will do the trick:
> >>>
> >>> Cmnd_Alias NAGIOS_CMNDS = /sbin/camcontrol inquiry da0
> >>>
> >>> man sudoers for more information about what you can do with sudo.
> >>
> >> I just realised this example is woefully incomplete - apologies for
> >> that.
> >>
> >> There are a few ways you can set up /usr/local/etc/sudoers (make sure
> >> you use visudo to edit it, as it will catch any syntax errors for you,
> >> thus helping somewhat to prevent breaking your setup).
> >>
> >> The simplest case will just be to allow nagios to run the command, as
> >> root,
> >> without a password:
> >>
> >> nagios ALL=(root) NOPASSWD: /sbin/camcontrol inquiry da0
> >>
> >> If, as is quite possible, nagios should be able to run more than just
> >> that one command, you can define a Cmnd_Alias, as above. To include more
> >> than one command in the alias, simply separate them with a comma. You
> >> can use `\' to escape newlines and make your file a little easier to
> >> read:
> >>
> >> Cmnd_Alias NAGIOS_CMNDS = /sbin/camcontrol inquiry da0 \
> >>                           /sbin/camcontrol inquiry da1
> >>
> >> and so on. Now, to use that alias, set the user's permissions to
> >>
> >> nagios ALL=(root) NOPASSWD: NAGIOS_CMNDS
                 ^^^^

> For the records, even this won't work because nagois needs access to
> /dev/xpt0 as well and once there sudo can't help.
>
> sudo -u nagios /sbin/camcontrol inquiry da0
> camcontrol: cam_lookup_pass: couldn't open /dev/xpt0
> cam_lookup_pass: Permission denied

The idea is to let this be run as root, tho personally, I'd put nagios in a 
group that can rw /dev/xpt0, /dev/pass0 and /dev/da0, setup devfs.rules 
properly and the let it execute a script that does the inquiry and the 
inquiry only.

On a related note, it would be a 'nice to have', if the more dangerous 
commands of camcontrol had a sysctl knob that only allows them to be executed 
only as root.
-- 
Mel

Problem with today's modular software: they start with the modules
    and never get to the software part.