[ovs-dev] [PATCH v2 1/8] ofproto: Allow xlate_actions() to fail.

[Ben Pfaff]

On Fri, Nov 06, 2015 at 04:10:48PM -0800, Jarno Rajahalme wrote:
> Sometimes xlate_actions() fails due to too deep recursion, too many
> MPLS labels, or missing recirculation context.  Make xlate_actions()
> fail in these circumstances, so that we can install a drop flow
> instead of a flow with partially translated actions.
> 
> Before this action it was possible that the revalidation installed a
> flow with a recirculation ID with an invalid recirc ID (== 0), due to
> the introduction of in-place modification in commit 43b2f131a229
> (ofproto: Allow in-place modifications of datapath flows).
> 
> Signed-off-by: Jarno Rajahalme <jrajahalme at nicira.com>

Do the callers do something on failure that is significantly different
from what they'd do on a success that returns no actions?  Flow
translation is already hard enough for the clients to get right, and it
would be ideal if they didn't have to be even more careful.