[comp.protocols.nfs] PC-NFS permissions

15340TDD@MSU.BITNET (Tom Davis) (07/29/89)

Another PC-NFS question...  I have a file system "mounted" with PC-NFS and
I am having difficulty "touching" a file from the PC.  If I have OWNER
privileges on the file it works fine, but if I have GROUP privileges on
the file it fails!  I have group privileges to the directory in both cases.
What gives??

geoff@hinode.East.Sun.COM (Geoff Arnold @ Sun BOS - R.H. coast near the top) (08/01/89)

In article <13415340TDD@MSU> 15340TDD@MSU.BITNET (Tom Davis) writes:
>Another PC-NFS question...  I have a file system "mounted" with PC-NFS and
>I am having difficulty "touching" a file from the PC.  If I have OWNER
>privileges on the file it works fine, but if I have GROUP privileges on
>the file it fails!  I have group privileges to the directory in both cases.
>What gives??

This seems to be an artefact of the NFS server implementation. When you
issue a SetAttributes call the server checks to see if you are the owner of
the file; if you are not, and you are trying to change certain key attributes,
the call is rejected. We ran into this when fixing a bug (NOT fixed in 3.0.1)
when a non-owner was trying to shrink a file. PC-NFS issues a SetAttributes
with the new file size, but incorrectly includes the permission bits
in the settable attributes structure. The NFS server rejects the whole
request and the file doesn't shrink.

Geoff

Geoff Arnold,                              Internet: garnold@East.Sun.COM
Manager, PC-NFS Engineering                UUCP: ....!sun!East!garnold
PCDS Group, Sun Microsystems Inc.

mike@relgyro.stanford.edu (Mike Macgirvin) (08/08/89)

In article <648@east.East.Sun.COM> geoff@hinode.East.Sun.COM (Geoff Arnold @ Sun BOS - R.H. coast near the top) writes:
>In article <13415340TDD@MSU> 15340TDD@MSU.BITNET (Tom Davis) writes:
>>Another PC-NFS question...  I have a file system "mounted" with PC-NFS and
>>I am having difficulty "touching" a file from the PC.  If I have OWNER
>>privileges on the file it works fine, but if I have GROUP privileges on
>>the file it fails!  I have group privileges to the directory in both cases.
>
>This seems to be an artefact of the NFS server implementation. When you
>issue a SetAttributes call the server checks to see if you are the owner of
>Geoff Arnold,                              Internet: garnold@East.Sun.COM
>Manager, PC-NFS Engineering                UUCP: ....!sun!East!garnold
>PCDS Group, Sun Microsystems Inc.

	With all respects, Geoff, I think Mr. Davis might just be talking
about the 'one GID' problem with PC-NFS. PC-NFS, at least to 3.0, only
allows you to be a member of ONE group, which is the one in your passwd
file on the server. Touching files with which you have group access under
Unix, cannot be done under DOS if they are not your default group.
	I was told by Mr. Arnold (several months ago) that this would be
fixed in a future PC-NFS release, using YP maps to bring the full spectrum
of Unix groups into the PC's domain.
	I have patched an earlier release of the 'pcnfsd.c' authentication
daemon to allow one to 'login' to a given group to which he/she has access,
so that they can use the files which they can use under Unix. I might be
able to send someone the hacked up version, but it still is a contorted
solution, which still allows only ONE group, but it can be any group you
belong to, and you can 'login' again to change groups.

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+  Mike Macgirvin                                                           +
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geoff@hinode.East.Sun.COM (Geoff Arnold @ Sun BOS - R.H. coast near the top) (08/09/89)

In article <321@helens.Stanford.EDU> mike@relgyro.STANFORD.EDU (Mike Macgirvin) writes:
>	[...] I think Mr. Davis might just be talking
>about the 'one GID' problem with PC-NFS. PC-NFS, at least to 3.0, only
>allows you to be a member of ONE group, which is the one in your passwd
>file on the server. Touching files with which you have group access under
>Unix, cannot be done under DOS if they are not your default group.

I don't know which he was talking about, but both issues need
to be resolved.

>	I was told by Mr. Arnold (several months ago) that this would be
>fixed in a future PC-NFS release, using YP maps to bring the full spectrum
>of Unix groups into the PC's domain.

This is indeed fixed in 3.0.1. I'm going to post the info on 3.0.1
in a moment.

Geoff

Geoff Arnold,                              Internet: garnold@East.Sun.COM
Manager, PC-NFS Engineering                UUCP: ....!sun!East!garnold
PCDS Group, Sun Microsystems Inc.