On Tue, Dec 01, 2015 at 03:59:56PM +0100, Mateusz Guzik wrote: > CHROOT_IN/OUT around commandvf are definitely problematic. chroot should be > done in the child, which also removes the need to chroot out in the > parent.
The CHROOT_IN/OUT business does need to be rewritten. Every instance where we currently do something like: CHROOT_IN; r = stat (fd, &statbuf); CHROOT_OUT [https://github.com/libguestfs/libguestfs/blob/master/daemon/stat.c#L93-L95] should instead be forking a subprocess, chrooting in the subprocess, and doing the system call in the subprocess. The problem which makes it not so easy is that instead of using a nice local variable, we would have to pass back the result from a subprocess to the parent process (the pair (r, statbuf) in the above example). So that means .. a pipe, and serializing the result down the pipe. The good news is that since this all runs on the same machine in the same compiled program, it's quite acceptable to dump a C struct into the pipe. But it's still a lot of work .. patches welcome of course. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html _______________________________________________ Libguestfs mailing list Libguestfs@redhat.com https://www.redhat.com/mailman/listinfo/libguestfs
