[ovs-dev] [PATCH 2/8] ofp-util: Flow Dump Protocol for OpenFlow 12

[Ben Pfaff]

On Tue, Nov 20, 2012 at 09:39:56AM +0900, Simon Horman wrote:
> On Mon, Nov 19, 2012 at 10:13:22AM -0800, Ben Pfaff wrote:
> > On Mon, Nov 19, 2012 at 02:59:29PM +0900, Simon Horman wrote:
> > > Allow only OpenFlow 12 as a flow dump protocol for OpenFlow12.
> > > Allow OpenFlow10 and NXM as flow dump protocols for other OpenFlow versions.
> > > This only changes the behaviour prior to this patch in the case of OpenFlow12
> > > which seemed broken as an attempt would be made to set NXM as the
> > > flow dump format using an OpenFlow 1.0 message even though an OpenFlow 1.2
> > > connection had been negotiated..
> > > 
> > > Signed-off-by: Simon Horman <horms at verge.net.au>
> > 
> > I think that this is no longer needed with the changes that I made a few
> > patches back.  set_protocol_for_flow_dump() will try to set the protocol
> > with try_set_protocol(), which in turn will call
> > ofputil_encode_set_protocol(), which in turn will see that the versions
> > are incompatible, with:
> > 
> >     cur_version = ofputil_protocol_to_ofp_version(current);
> >     want_version = ofputil_protocol_to_ofp_version(want);
> >     if (cur_version != want_version) {
> >         *next = current;
> >         return NULL;
> >     }
> > 
> > which makes try_set_protocol() return that it failed to set that
> > protocol, which makes set_protocol_for_flow_dump() go on to the next
> > one.
> 
> I'm somewhat unsure how you envisage this working.
> 
> Without this patch  the code you refer to does indeed see that
> all versions are incompatible. But in the end it runs out of options
> and produces a fatal error.

Do we just need to add OFPUTIL_P_OF12_OXM to
ofputil_flow_dump_protocols[], at the beginning?