Messages in this thread | | | Date | Thu, 4 Dec 2008 13:24:12 -0600 | From | "Serge E. Hallyn" <> | Subject | Re: [PATCH 2/6] integrity: Linux Integrity Module(LIM) |
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Quoting Christoph Hellwig (hch@infradead.org): > On Wed, Dec 03, 2008 at 05:17:35PM -0500, Mimi Zohar wrote: > > > I have a bit of a problem parsing the above, and it certainly doesn't > > > look like a justification for keeping all that unused code around. > > > > The purpose of LIM is to provide an integrity infrastructure to support > > different types of integrity data. IMA implements both the LIM > > API for it's own internal use, and exports it for others to call. > > > > As Dave Safford pointed out in http://lkml.org/lkml/2008/11/17/362, > > there are other projects that want to add differently structured > > measurements to the TPM measurement list. The template abstraction is > > critical to allowing these differently formatted messages to be added to > > the list. > > I think we're talking past each other. > > In integrity.h there are two operation vectors defines: > > - struct integrity_operations delcares the operations called from the > VFS. This one is actually used. While I don't agree to Dave's > argument, because we don't put bloat in just because people might > eventually some day use it when they are in the right mood and the > sun shines, thisn't isn't the one I'm talking about in this thread. > - struct template_operations on the others is not only really badly > named for appearing in a global header but also not used in a > meaningfull way. There is one single instace of it, > ima_template_ops, and while there are five helpers added in the > second patch that use it (integrity_collect_measurement, > integrity_appraise_measurement, integrity_store_measurement, > integrity_store_template, integrity_must_measure) none of them > is used at all during the patch series. There are two direct > uses of these template added in the third path, to implement the > show operations for the "binary_runtime_measurements" and > "ascii_runtime_measurements" files ins securityfs, but given that > those are inside ima there no reason for the indirection at all.
Yeah I can definately see that.
Mimi, you used to have another template (I thought) which just tracked security_ops to try and prevent subversion of the LSM hooks. Or something like that. That was a separate template_ops, right? Can you post that again? That might answer both Christoph's query about the usefulness of the indirection, and Dave's question about "how could I use this, anyway".
If you do repost it, please be very clear about what it is expected to do/protect against, and how, using no acronyms which you don't define on first use :)
thanks, -serge
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