Re: sys_vserver

[Chris Wright <chrisw@osdl.org>]

* Herbert Poetzl (herbert@13thfloor.at) wrote:
> 
> one of the advantages the current _and_ future vserver project
> has over 'changing/setting some features for a process' is the
> concept of a context layer, residing between kernel and processes
> _belonging_ to a context ...

Yes, I agree, this is a useful abstraction.

> you could, for example set up a context which allows a maximum
> of 10 processes, limited to one ethernet interface, using it's
> own root/user quota, start some 'virtual' server in this context
> doing all this init stuff, and then visit this context from
> outside, via a simple 'context' change ... if you've got the
> right capabilities/permissions ...
> 
> I can not imagine how you would do that with the /proc/<pid>/attr/
> interface, but I'm sure you can explain it to me ...

Put it this way, typical security modules have a notion of a
context, and the ability to grant/deny actions base on the context.
The /proc/<pid>/attr interface is how you can set/retrieve the context
per process, and subsequent fork/exec's can chose how to propagate
that context.  I believe a reasonable portion of vserver can become a
security module, but there would clearly remain a need for some of the
virtualization (e.g. hostname, etc.).

thanks,
-chris
-- 
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