internal label representation

[Ilmar S. Habibulin]

On Fri, 26 Oct 2001, Robert Watson wrote:

> > I'm thinking of making network interconnection possible in trustedbsd.
> > Rigth now i can't directly insert my work in mac patch, cause existing
> > label representation differs from mine. So maybe change it? There is
> > type field, so what if just replace it with special label levels (HIGH,
> > LOW and EQUAL?). So i would be able to label network packets as equal
> > and let them pass in (This is the case of trusted server and labeled
> > client exchange, when server have to deal with different labeled
> > clients).
> I borrowed this model from the SGI approach, which uses a tuple that
> includes a type field in each label.
I saw it in their sources.

> In a purely hierarchal scheme, I think you're right that it does add some
> complexity.  However, in a model with non-hierarchal components, it seemed
> simpler to me.  Also, it avoids the classic bug case where magic values
> are taken out of a namespace to have special meaning, but are
> inconsistently checked.  I'm not opposed to changing, however.  Right now,
Well, i'll try to explain what i want to do and why do i propose to use
"magic value" for the label. If two processes exchange packets using UDP
then they must have equal labels (i simplify this case and will not review
label ranges), but if we have DNS lookup queries or portmap(rpcbind)
queries, then trusted server (named or rpcbind) must supply correct label
in the reply packet. So i propose the simpliest solution - use some "magic
value" as "equal label" in UDP packets. It's just to make labeling work
over network somehow, because i'm affraid of changing systems' API and
different server programs (some of them are contributed). I think it is
hard work and can be done in the next MAC implementation iteration.

> I'm working to integrate your higher level VFS approach to access control
> into my MAC patch, and also setting up a Perforce repository for the work
What is Perforce?

> on FreeBSD.org.  I hope to have a new patch available within a week or two
> that incorporates these changes, and propagate access control and labeling
> further through the tree.
Be waiting for.
And what about capabilities patch? Will you commit it someday?



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