On Thu, Sep 21, 2023 at 03:58:01PM -0500, Eric Blake wrote: > When fuzzing, it is more desirable to always provoke the server into > sending a response, rather than sometimes accidentally skipping a wire > call because a client-side strictness test failed. > > [Our fuzzer could probably be made even more powerful by changing the > fuzzer input file to be a series of records, where each record is the > API to call and then the server's response; right now, the sequence of > APIs called is hard-coded, which is not as powerful at testing > potential cross-command coupling. But that's a project for another > day.]
Intrigued by how this would work exactly. The current file is just a stream of bytes from the "server" (the output from libnbd is discarded). Would the input file be of the form: ( [ request + args ] [ stream of bytes from server ] )* where [ request + args ] would be a simple serialized representation of a synchronous nbd_* API call? I think that would work ... Rich. > Signed-off-by: Eric Blake <ebl...@redhat.com> > Reviewed-by: Richard W.M. Jones <rjo...@redhat.com> > Reviewed-by: Laszlo Ersek <ler...@redhat.com> > --- > fuzzing/libnbd-fuzz-wrapper.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/fuzzing/libnbd-fuzz-wrapper.c b/fuzzing/libnbd-fuzz-wrapper.c > index cbd55380..fcd1d04c 100644 > --- a/fuzzing/libnbd-fuzz-wrapper.c > +++ b/fuzzing/libnbd-fuzz-wrapper.c > @@ -193,8 +193,11 @@ client (int sock) > } > > /* Note we ignore errors in these calls because we are only > - * interested in whether the process crashes. > + * interested in whether the process crashes. Likewise, we don't > + * want to accidentally avoid sending traffic to the server merely > + * because client side strictness sees a problem. > */ > + nbd_set_strict_mode (nbd, 0); > > /* Enable a metadata context, for block status below. */ > nbd_add_meta_context (nbd, LIBNBD_CONTEXT_BASE_ALLOCATION); > -- > 2.41.0 -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top _______________________________________________ Libguestfs mailing list Libguestfs@redhat.com https://listman.redhat.com/mailman/listinfo/libguestfs
