[ovs-discuss] Anyway to move/load data between ct_mark/ct_label and field/register ?

[Ben Pfaff]

What's your high-level goal?  Most fields will be the same on every trip
through the connection tracker for a given (half-)connection, so there
would be limited value in that.

On Thu, May 11, 2017 at 02:37:13PM +0000, Zang MingJie wrote:
> It can only set to immediately value, I want to copy some field into
> ct_label
> 
> On Thu, May 11, 2017, 21:30 Ben Pfaff <blp at ovn.org> wrote:
> 
> > On Thu, May 11, 2017 at 11:11:58AM +0000, Zang MingJie wrote:
> > > I wonder if there is any way to move data from or to ct_label like nicira
> > > move or load extension ?
> > >
> > > I want to store some value of packet field or register to ct_lable on the
> > > first packet, and the load ct_label to some fields of the following
> > packet.
> >
> > ovs-ofctl(8) says, in the documentation for the ct action:
> >
> >                      exec([action][,action...])
> >                             Perform  actions  within the context of
> > connection
> >                             tracking. This is  a  restricted  set  of
> > actions
> >                             which  are  in the same format as their
> > specifica‐
> >                             tions as part of a flow. Only actions which
> > modify
> >                             the ct_mark or ct_label fields are accepted
> > within
> >                             the exec action, and these fields may only be
> > mod‐
> >                             ified with this option. For example:
> >
> >                             set_field:value[/mask]->ct_mark
> >                                    Store a 32-bit metadata value with the
> > con‐
> >                                    nection.  Subsequent lookups for
> > packets in
> >                                    this  connection  will populate the
> > ct_mark
> >                                    flow field when the packet is sent  to
> > the
> >                                    connection  tracker  with  the table
> > speci‐
> >                                    fied.
> >
> >                             set_field:value[/mask]->ct_label
> >                                    Store a 128-bit  metadata  value  with
> > the
> >                                    connection.  Subsequent lookups for
> > packets
> >                                    in  this  connection  will   populate
> >  the
> >                                    ct_label flow field when the packet is
> > sent
> >                                    to the connection tracker  with  the
> > table
> >                                    specified.
> >
> >                             The  commit  parameter  must  be  specified to
> > use
> >                             exec(...).
> >