Subject: Re: [vserver] pam_namespace inside a vserver
From: Herbert Poetzl <herbert@13thfloor.at>
Date: Tue, 6 Oct 2009 01:44:27 +0200

On Mon, Oct 05, 2009 at 07:46:23PM +0200, Wilhelm Meier wrote:

> 
> we use a vserver as terminal-server, quite a normal setup, i think.
> The host and guest are both debian lenny.

> For some reason we need a polyinstantiated /media directory. i would 
> like to do this with pam_namespace.

hmm .. could you elaborate on that?
sounds to me like you want to mount something there?

> When I use pam_namespace in the pamm-session-stack I get the following 
> error:

> Oct  5 19:28:23 192.168.222.12 kdm: 
> rich00E0C5600493.intern.kmux.de:1[27525]: pam_namespace(kdm:session): 
> Unable to unshare from parent namespace, Operation not permitted

assuming that the pam module does an unshare with
CLONE_NEWNS, you can permit that with the context
capability VXC_NAMESPACE

> It is not clear to me if this is possible, because it would
> result in somehow nested namespace: the new namespace inside the
> vserver-namespace?

a Linux-VServer guest consists of several namespaces,
the filesystem/mount namespace is only one of them
and more than that, it is fully hierarchical, so that
should be fine :)

> Any hints how to do this?

get recent and working kernel, use VXC_NAMESPACE, be happy :)

best,
Herbert

if you or your company use and like the Linux-VServer project, 
why not consider donating hardware or money, or getting a
service contract with the developers to ensure that it will
live on and continue to provide high quality free software?

> -- 
> Wilhelm