Re: [PATCH] Drop Posix Capabilities

[Steve Grubb <sgrubb@redhat.com>]

On Sunday 27 September 2009 04:31:25 pm Marcel Holtmann wrote:
> > > > +AC_DEFUN([LIBCAP_NG_PATH],
> > > > +[
> > > > +     AC_ARG_WITH(libcap-ng,
> > > > +     [ --with-libcap-ng=[auto/yes/no]  Add Libcap-ng support
> > > > +             [default=auto]],, with_libcap_ng=auto)
> > > > +
> > >
> > > I mention this to Bastien already. I want pkgconfig support here and
> > > not some old style aclocal magic.
> >
> > libcap-ng itself does not provide any pkgconfig support. I'll check on
> > this.
> 
> According to the bug you guys have open for this, you try to fix this
> upstream in libcap-ng. So please push a pkgconfig file to libcap-ng and
> then I am more than happy to accept a patch for this.

The bug report only said pkg-config support might be nice, but it was not 
specified as a requirement. Anyways, I made a new release of libcap-ng today 
with a pkg-config file added. There are no other user of that file, so please let 
me know if something is wrong with it.

http://people.redhat.com/sgrubb/libcap-ng/libcap-ng-0.6.2.tar.gz
 
> I like to have capability dropping in bluetoothd, but I do wanna do it
> with a proper upstream project.

one other thing I thought I would point out. The patch I sent can make it easy 
to run the bluetooth daemon as non-root user. If we switch this line:

capng_apply(CAPNG_SELECT_BOTH);

to

capng_change_id(uid, gid, CAPNG_DROP_SUPP_GRP | CAPNG_CLEAR_BOUNDING);

then the job is easier. Of course you would likely need to fixup file 
permissions in places, but in theory a non-root bluetooth daemon is possible 
with a 1 line change in the patch. You would probably want to add error 
handling and a way to specify the uid/gid, too.

-Steve