On 10/14/2017 08:01 PM, Eric Blake wrote: > From: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> > > Minimal implementation of structured read: one structured reply chunk, > no segmentation. > Minimal structured error implementation: no text message. > Support DF flag, but just ignore it, as there is no segmentation any > way. > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> > Signed-off-by: Eric Blake <ebl...@redhat.com> >
> +
> + case NBD_OPT_STRUCTURED_REPLY:
> + if (client->structured_reply) {
> + ret = nbd_negotiate_send_rep_err(
> + client->ioc, NBD_REP_ERR_INVALID, option, errp,
> + "structured reply already negotiated");
> + } else {
> + ret = nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK,
> + option, errp);
> + }
Fails spectacularly if the client sent a non-zero length payload along
with the option, because we forgot to nbd_drop the payload, getting the
server out-of-sync with the client's next option request. I'm
requesting clarification from the NBD list on how to best handle that
(presumably with NBD_REP_ERR_INVALID), and in the meantime will copy
what we do for NBD_OPT_LIST with unexpected payload. It also made me
realize that we don't reject unexpected payload for NBD_OPT_STARTTLS; a
common helper function would make that easier, so guess what I'm adding
in v5 :)
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
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