On Fri, Apr 24, 2020 at 02:50:43PM +0000, Luca Mancini wrote: > I am trying to implement a new openflow action on an openvswitch, that upon > request by the controller buffers a given packet. > > So assume a topology like H1—s1--s2—H2 where h1 sends packets to h2, the > controller would specify a BUFFER action to all packets going from h1 to h2 > Making the s1 switch create a buffer where all these packets are stored until > the buffer is full and then send the buffer (as a new packet) down the path > to H2. > I have found very little material regarding the implementation of a new > openflow action to ovs: > > I followed this guide a little bit but I’m finding some things a bit > confusing https://mcfelix.me/blog/modifying-ovs/ > Some questions I have are: > -is this type of action possible? > -where exactly do I need to code the actual action function? > -how and where are packets defined in OVS? I’m having trouble understading if > the packet I need to be storing is the sk_buff that is passed as a parameter > or if it’s something else
This should be possible. You'll need to make the action send packets that need to be buffered to userspace, with a "userspace" kernel action. Then you can accumulate the packets in userspace until they should be released. Since you'll only be dealing with userspace packets, struct dp_packet is primarily what you need to care about. The FAQ says this: Q: How do I add support for a new OpenFlow action? A: Add your new action to ``enum ofp_raw_action_type`` in ``lib/ofp-actions.c``, following the existing pattern. Then recompile and fix all of the new warnings, implementing new functionality for the new action as needed. (If you configure with ``--enable-Werror``, as described in the :doc:`/intro/install/general`, then it is impossible to miss any warnings.) If you need to add an OpenFlow vendor extension action for a vendor that doesn't yet have any extension actions, then you will also need to add the vendor to ``vendor_map`` in ``build-aux/extract-ofp-actions``. Also, you will need to add support for the vendor to ``ofpact_decode_raw()`` and ``ofpact_put_raw()`` in ``lib/ofp-actions.c``. (If you have a choice of how to design your vendor extension actions, it will be easier if you make them resemble the ONF and OVS extension actions.) _______________________________________________ discuss mailing list disc...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-discuss