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Re: [Xense-devel] ACM doesnt scale

To: aq <aquynh@xxxxxxxxx>
Subject: Re: [Xense-devel] ACM doesnt scale
From: Reiner Sailer <sailer@xxxxxxxxxx>
Date: Fri, 24 Jun 2005 22:22:41 -0400
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> > 
> > Could you plesae be a little more specific about the "scaling"?  What 
is
> > your
> > application of the ACM module that determines there's a "scaling" 
problem?
> > 
> 
> at the moment, all the security models (chinesewall (A) and ste (B))
> are hard-coded, and we have 3 combinations of models (not count NULL
> policy): A, B and A_AND_B.
> 
> i guess that there are more models to come in the future, suppose 3:
> C, D, E. so we will have much more combinations. and obviously the
> current organization of code in ACM doesnt scale to that change.
> 
> regards,
> aq
> 
> 
I can't see how it does not scale. If you would like to add a new policy,
you just write a file alike those that are implementing chinese wall or
type enforcement. Then you set primary or secondary policy to this model.

For example, if you would like to use a multi-level security policy 
instead 
of the type enforcement policy, then just register the your multi-level 
policy.

One thing that seems benefitial here would be separate #defines
for the separate policies instead of a single one. Other than that
you might need to add one or two lines of code to the acm_init that 
sets the policies according to the two separate #defines for primary
and secondary policy. If need be, the acm_init can VERY easily be 
adapted to the need.

Since all policy-specific management functions (init, dumppolicy, 
setpolicy,initstate...) are defined in the hooks, the management 
scales as well (if code-size and complexity is the factor).

Not such a big deal.

Reiner

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