Re: [PATCH ghak90 V6 05/10] audit: add contid support for signalling the audit daemon

From: Neil Horman
Date: Tue Apr 09 2019 - 09:49:33 EST


On Tue, Apr 09, 2019 at 09:40:58AM -0400, Paul Moore wrote:
> On Tue, Apr 9, 2019 at 8:58 AM Ondrej Mosnacek <omosnace@xxxxxxxxxx> wrote:
> >
> > On Tue, Apr 9, 2019 at 5:40 AM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> > > Add audit container identifier support to the action of signalling the
> > > audit daemon.
> > >
> > > Since this would need to add an element to the audit_sig_info struct,
> > > a new record type AUDIT_SIGNAL_INFO2 was created with a new
> > > audit_sig_info2 struct. Corresponding support is required in the
> > > userspace code to reflect the new record request and reply type.
> > > An older userspace won't break since it won't know to request this
> > > record type.
> > >
> > > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> >
> > This looks good to me.
> >
> > Reviewed-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
> >
> > Although I'm wondering if we shouldn't try to future-proof the
> > AUDIT_SIGNAL_INFO2 format somehow, so that we don't need to add
> > another AUDIT_SIGNAL_INFO3 when the need arises to add yet-another
> > identifier to it... The simplest solution I can come up with is to add
> > a "version" field at the beginning (set to 2 initially), then v<N>_len
> > at the beginning of data for version <N>. But maybe this is too
> > complicated for too little gain...
>
> FWIW, I believe the long term solution to this is the fabled netlink
> attribute approach that we haven't talked about in some time, but I
> keep dreaming about (it has been mostly on the back burner becasue 1)
> time and 2) didn't want to impact the audit container ID work). While
> I'm not opposed to trying to make things like this a bit more robust
> by adding version fields and similar things, there are still so many
> (so very many) problems with the audit kernel/userspace interface that
> still need to be addressed.
>

Agreed, this change as-is is in keeping with the message structure that audit
has today, and so is ok with me, but the long term goal should be a conversion
to netlink attributes for all audit messages. Thats a big undertaking and
should be addressed separately though.

Neil

> --
> paul moore
> www.paul-moore.com
>