compilation problems with some code from Linux

[Andrew Falanga]

Hi,

I'm trying to port some code from Linux to FreeBSD and I've got an issue
that revolves around something I've never dealt with before.  The code
includes the following header:

#include <sys/ucred.h>

Apparently, program is attempting to make use of the xucred structure
defined in there, because the rest of the stuff in the file seems to be for
the kernel.  However, when I try to compile, gcc continually bails with the
following error (among others), "NGROUPS was not declared in this scope."
The NGROUPS appears to be a macro, but it's not defined earlier on.  Would
anyone here know where it's defined so I can include that file too?

Secondly, I'm also getting errors because gcc can't find <sys/vfs.h>
either.  True enough, there isn't any vfs.h file in /usr/include/sys.  Since
this file is in Linux, what should I include for FreeBSD?

Thanks,
Andy