[ovs-discuss] FF group liveness

[Ben Pfaff]

On Fri, Apr 08, 2016 at 10:24:31AM +0200, Miklós Pelyva wrote:
> Hi!
> 
> I have a question regarding some difference between OpenFlow protocol
> version 1.3.5 and vanilla Open vSwitch implementation version 2.5.0.
> 
> If someone would like to use fast failover type group without bucket
> liveness set, then it would return an OFPERR_OFPGMFC_INVALID_GROUP error
> code.
> However, based on the protocol (1.3.5) invalid group error should be
> returned only in the following two cases:
> 1) "If a specified group type is invalid (ie: includes fields such as weight
> that are unde ned for the specified group type) then the switch must refuse
> to add the group entry and must send an ofp_error_msg with
> OFPET_GROUP_MOD_FAILED type and OFPGMFC_INVALID_GROUP code."
> 2) "If a delete request includes some buckets in the Group-Mod message, then
> the switch must return an ofp_error_msg with OFPET_GROUP_MOD_FAILED type and
> OFPGMFC_INVALID_GROUP code."
> 
> The particular piece of code from ofp-util.c in ofputil_decode_group_mod,
> l:8878 is the following:
>         case OFPGT11_FF:
>             if (!ofputil_bucket_has_liveness(bucket)) {
>                 return OFPERR_OFPGMFC_INVALID_GROUP;
>             }
>             break;
> 
> Is the above error code handling not written into the protocol by purpose or
> by accident, or is it just not explicitly determined by the protocol how to
> handle fast failover type groups without bucket liveness?

"Invalid group" seems like a reasonable error code to me for this
problem.  What error code do you prefer?