NFSv4 ACLs

[J. Bruce Fields]

On Fri, Apr 20, 2012 at 11:55:53AM -0700, Jeremy Allison wrote:
> On Fri, Apr 20, 2012 at 12:04:02PM +0200, Ondrej Valousek wrote:
> > Hi List,
> > 
> > I know this has been asked many times, but I will ask one more time:
> > I would like to export NFSv4 mounted filesystem with Samba and would
> > like to be able to use windows "security tab" in explorer to modify
> > these ACLs.
> > Do I have any chance with Samba on RHEL-5/6?
> 
> Does Linux have local API's to manipulate mounted NFSv4 ACLs ?
> 
> Samba has VFS modules to cope with mapping Windows ACLs onto
> NFSv4 ACLs but currently they only work on AIX, Linux with IBM's
> gpfs and Solaris right now.
> 
> If you can point me a docs showing the library APIs for Linux
> to allow programatic manipulation of NFSv4 ACLs then I can
> make it work on Linux too.

It's a bit idiosyncratic, but should be easy enough to handle if you
want, I think: on the linux client, on an nfs4 filesystem, the
"system.nfs4_acl" xattr contains the xdr-encoded ACL as it came in on
the wire (network-byte-order and all).  See the definition of fattr4_acl
in rfc 3530.

--b.