lkml.org 
[lkml]   [2007]   [Aug]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] Send quota messages via netlink
On Wed 29-08-07 15:06:43, Eric W. Biederman wrote:
> Jan Kara <jack@suse.cz> writes:
> >> However I'm still confused about the use of current->user. If that
> >> is what we really want and not the user who's quota will be charged
> >> it gets to be a really trick business, because potentially the uid
> >> we want to deliver varies depending on who opened the netlink socket.
> > I see it's a complicated matter :). What I need to somehow pass to
> > userspace is something (and I don't really care whether it will be number,
> > string or whatever) that userspace can read and e.g. find a terminal
> > window or desktop the affected user has open and also translate the
> > identity to some user-understandable name (average user Joe has to
> > understand that he should quickly cleanup his home directory ;).
> > Thinking more about it, we could probably pass a string to userspace in
> > the format:
> > <namespace type>:<user identification>
> >
> > So for example we can have something like:
> > unix:1000 (traditional unix UIDs)
> > nfs4:joe@machine
> >
> > The problem is: Are we able to find out in which "namespace type" we are
> > and send enough identifying information from a context of unpriviledged
> > user?
>
> Ok. This provides enough context to understand what you are trying to do.
> You do want the unix user id, not the filesystem notion. Because you
> are looking for the user.
>
> So we have to figure out how to do the hard thing which is look at
> who opened our netlink broadcast see if they are in the same user
> namespace as current->user. Which is a pain and we don't currently
> have the infrastructure for.
There can be arbitrary number of listeners (potentially from different
namespaces if I understand it correctly) listening to broadcasts. So I
think we should pass some universal identifier rather than try to find out
who is listening etc. I think such identifiers would be useful for other
things too, won't they?
BTW: Do you have some idea, when would be the infrastructure clearer?
Whether it makes sence to currently proceed with UIDs and later change it
to something generic or whether I should wait before you sort it out :).

Honza
--
Jan Kara <jack@suse.cz>
SuSE CR Labs
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-08-30 11:09    [W:0.156 / U:0.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site