On Fri, Dec 21, 2012 at 6:42 PM, Ethan Jackson <et...@nicira.com> wrote: > >> I'm not sure that OFPP_NONE is the right value to return here, at >> least not without additional checks. Before both >> handle_miss_upcalls() and handle_sflow_upcalls() explicitly checked >> for not being able to find an ofport before and would abort. However, >> now I think they will silently continue with a different meaning. At >> the very least, we've lost some logging of this situation in >> handle_miss_upcalls() > > > Actually, I think the existing code has the correct behavior, it's just > written badly and therefore confusing. Both handle_miss_upcalls() and > handle_sflow_upcalls() pass in 'ofproto' to ofproto_receive(). Therefore, > ofproto_receive() will return ODP_FIT_ERROR when it attempts to populate > 'ofproto' if there is no corresponding ofport. That said, this is terribly > confusing, and should be refactored.
OK, I see that now. > Ideally, I would just return ODP_FIT_ERROR whenever odp_port_to_ofport() > fails. However, trace relies on being able to set no, or a non-existent > ofport and proceeding with an in_port of OFPP_NONE. That's why I > implemented it this way. I'm wondering if we should just remove that > feature, and require the in_port to trace actually exist? I don't have a > sense of how useful it is to be able to specify OFPP_NONE as an in_port in > this case. The unit tests utilize it fairly extensively at any rate. OpenFlow allows sending packets like this (and it's actually a relatively common behavior in some applications) so it's probably important to allow trace to handle them. I think the main problem is that it is just done implicitly. handle_miss_upcall() used to log this situation, which probably isn't a bad idea and if we enabled that to happen then it might have the effect of making things more obvious in general. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
