[ovs-discuss] ofputil_check_output_port() should permit NONE as port

[Ben Pfaff]

On Mon, Jul 25, 2011 at 06:37:34PM +0200, Andreas Schultz wrote:
> In lib/ofp-util.c, ofputil_check_output_port() validates to port in
> output actions. It currently rejects a output port with id NONE,
> however a output action with a port NONE is the only way to free all
> buffers associated with a packet without having to way for a timeout
> on the buffer.
>
> So it really should permit NONE as port id.

You're wrong about this in two ways.  First, you can use the empty set
of actions instead of an output action.  Second, OpenFlow 1.0 lists all
of the required and optional special ports supported by output actions
on page 6, and OFPP_NONE does not appear on the list.