libsemanage issue with bzip-blocksize=0 and compressed modules in store
On Mon, 2009-08-24 at 10:57 -0400, Chris PeBenito wrote:
> On Mon, 2009-08-24 at 10:04 -0400, Stephen Smalley wrote:
> > On Mon, 2009-08-24 at 09:54 -0400, Chris PeBenito wrote:
> > > I took the current release of libsemanage and added the patch to add a
> > > bzip blocksize option[1]. The modules in my store were already
> > > compressed with the stock release. I put bzip-blocksize=0 in my
> > > semanage.conf and I do semodule -B and get:
> > >
> > > libsepol.module_package_read_offsets: wrong magic number for module
> > > package: expected 0xf97cff8f, got 0x39685a42 (No such file or
> > > directory).
> > > libsemanage.semanage_load_module: Error while reading from module
> > > file /etc/selinux/strict/modules/tmp/modules/apm.pp. (No such file or
> > > directory).
> > > semodule: Failed!
> > >
> > > If I do semodule -l, it will also get the magic number error. If I
> > > remove the blocksize option, it works again. I was able to reinsert all
> > > of the modules to get it working again with the blocksize 0 option.
> > >
> > > [1] http://userspace.selinuxproject.org/trac/changeset/ee9827000137fed2d3300124115fc1572acafe2f
> >
> > Yes, that's what I would expect. The expectation is that either one
> > would set that option before installing the policy for the first time,
> > or that one completely re-installs the policy after setting that option.
>
> Can we have a little better handling of this case? I don't mind
> reinstalling the policy, but the error messages aren't helpful. In
> addition, with semodule -l being broken, I have to look into the module
> store to see what modules are installed or guess.
Seems like it is just as easy to just support pre-existing compressed
modules, see below.
Explicitly probe for the bzip2 magic string prefix and fall through to
BZ2_bzReadOpen() if the module is bzipped even if bzip-blocksize=0.
Thus bzip-blocksize=0 will prevent any further compression of
subsequently installed/updated modules, but will continue to function
with existing compressed modules.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
1 file changed