Subject: Re: NFSv4 ACL ambiguity

From: marius aamodt eriksen <[email-masked]>
Date: Thu, 22 Aug 2002 15:31:30 -0400

hi - 

in writing up a proposed method to map POSIX and NFSv4 ACLs, i more
closely exacmined the ACL text in the RFC.  i find the following to be
ambiguous:

   To determine if an ACCESS or OPEN request succeeds each nfsace4 entry
   is processed in order by the server.  Only ACEs which have a "who"
   that matches the requester are considered.  Each ACE is processed
   until all of the bits of the requester's access have been ALLOWED.
   Once a bit (see below) has been ALLOWED by an ACCESS_ALLOWED_ACE, it

   is no longer considered in the processing of later ACEs. If an
   ACCESS_DENIED_ACE is encountered where the requester's mode still has
   unALLOWED bits in common with the "access_mask" of the ACE, the
   requet is denied.

the ambiguitiy lies in that it does not specify what to do if the
requested access mask was not all ALLOWed, but also not DENYed.  i
have always assumed to deny in this case, but it is not clear.  if
this is the case, i propose to add the following sentence:

   When the ACL is is fully processed, if there are remaining
   unALLOWed bits in the mask, the request is denied.

marius.

-- 
> [email-masked] > http://www.citi.umich.edu/u/marius

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From: marius aamodt eriksen <[email-masked]>
Date: Thu, 29 Aug 2002 17:02:47 -0400

does anyone have an opinion on this?

marius.

--

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From: Mike Eisler <[email-masked]>
Date: Thu, 29 Aug 2002 13:35:44 -0700

> does anyone have an opinion on this?

Yes.

I think this is only an issue if you implement neither the
mode attribute nor the EVERYONE, or you allow files to not have the
mode and EVERYONE  ace. In which case, I think the results are
undefined. 

I'll propose some text.

	-mre