[Bacula-devel] Re: Development status of ACL support

[Michael K. J. <a12...@da...>]

On Thu, May 06, 2004 at 11:58:59PM +0200, Tim Oberf=F6ll wrote:
> I'm not sure if I'm experienced enough for such a task, but I would lik=
e to
> try it. So, a short summarize of what should be done would be great. Up=
 to
> now I worked a little bit with the libacl and wrote a tiny ACL backup p=
rogram
> (just writing the ACLs of a given path (and containing files) into a bz=
2
> file).
>
> Maybe with a summarize I'm able to rate if it is possible for me to hel=
p.

Well, I don't have to re-summarize the acl functions, since you already
know about them.  One thing that should be changed, however: after you
get the text form of the acl with acl_to_text, you will want to attach
text representations of the numeric owner and group.  Joerg Schilling,
in star, implemented the SCHILY vendor defined attributes for posix tar
with such an extension.  He says:
>The access control lists are stored in the short text form as
>defined in POSIX 1003.1e draft standard 17. To each named user
>ACL entry a fourth colon separated field field containing the
>user identifier (UID) of the associated user is appended. To each
>named group entry a fourth colon separated field containing the
>group identifier (GID) of the associated group is appended. (POSIX
>1003.1e draft standard 17 allows to add fields to ACL entries.)

This textual ACL information should then be stored in a stream;
bacula allows more than one stream per file.

Max can explain how to add new streams better than I can; he has
been in that source code for his MacOS work and I haven't.  You
might read the "HFSPlus Attribs & STREAM_UNIX_ATTRIBUTES_EX" thread
for more details on that.  (Ask me in private email if you want me
to bounce that whole thread to you.)

(Once this is done, storing EAs will be easy; there are similar
functions for manipulating EAs -- we'll just want to ignore all
system.posix_acl* keys while doing so, since the ACL functions
will deal with all those keys in a portable manner.)

michaelkjohnson

"Ever wonder why the SAME PEOPLE make up ALL the conspiracy theories?"