setgroups problems on FreeBSD - proposed fix

[Bjoern Jacke]

Hi James,

On Wed, May 23, 2007 at 08:35:46AM -0700, James Peach wrote:
> FWIW, Darwin does the same as FreeBSD ...

maybe you can bring some light into the dark here: I did some tests with
Darwin (OS X with most recent patches) to see how it behaves with the
maximum number of supplementary groups. sysctl says ngroups max is 16
like on all *BSD systems.

I saw that it is quite difficult to actually add any new groups on an
OS X client machine. I found that it is possible to add groups if you
download 50MB ServerAdminTools from Apple and connect to the "localhost"
server with the workgroup manager tool. This was the only way I found
out on OS X to add new groups, is there an easier way to create/manage
groups?

Then I put myself into 17 newly created groups but "id" was saying that
I would only be in 15 groups (including the group which is reported
to be my primary group - but I don't know if OS X is actually making a
difference between primary and supplementary groups internally, does it?).
So on OS X it only seems to be possible to have 14 supplementary groups
at all. Is this by design?

Thanks
Bjoern


PS: I've put up an overview of the different group limitations of Unix
systems at http://j3e.de/ngroups.html Comments and additions to this are
very welcome.