[ovs-dev] Implementation of Packet-Out in Bundles

[André Mantas]

Hi. I'm currently adding support for packet-out messages in bundles.

I started to look at *handle_packet_out*, *handle_bundle_add *and
*do_bundle_commit
*functions to understand how things work. Here is what I did in each
function:

*handle_bundle_add:* added if case for OFPTYPE_PACKET_OUT which does all
the validations performed in handle_packet_out as well as saving the
packet_out info in the bundle_entry. For this I added a new
ofproto_packet_out struct to the union in ofp_bundle_entry. This new struct
(created in the same way as ofproto_flow_mod and ofproto_port_mod) contains
an ofputil_packet_out, a dp_packet *payload and a flow. If I understand
correctly, this three structs are needed later to send the packet_out in
the commit phase.

*do_bundle_commit: *added if case for OFPTYPE_PACKET_OUT in phase 3
(finish) which calls the ofproto->ofproto_class->packet_out function using
the data saved in the bundle entry and then deletes de payload (as done in
handle_packet_out).
In phase 1 (begin) I only added prev_is_port_mod = false; to the packet-out
"if case" because all the validations were done before.

Is there a way to verify if the packet can be sent without actually sending
it?
If not, the ofproto->ofproto_class->packet_out can still return errors, but
this will be in the finish phase, which cannot be rolled back.
I think that in this case the bundle should still be committed (because it
does not affect other modifications like flow-mods and port-mods) and
errors can be returned to the controller. Would this be a good option?

I would also like to know if I'm going in the right direction or if I did
something wrong.

Thanks in advance.