Re: [PATCH net-next RFC] netfilter: flowtable: add CT metadata action for nft flowtables

[Pablo Neira Ayuso]

On Tue, Sep 16, 2025 at 07:49:34PM +0300, Elad Yifee wrote:
> Hi all,
> 
> One caveat: this change will cause some existing drivers to start
> returning -EOPNOTSUPP, since they walk the action list and treat any
> unknown action as fatal in their default switch. In other words, adding
> CT metadata unconditionally would break offload in those drivers until
> they are updated.
> 
> Follow-up patches will therefore be needed to make drivers either parse
> or safely ignore FLOW_ACTION_CT_METADATA. Because this action is only
> advisory, it should be harmless for drivers that don’t use it to simply
> accept and no-op it.
> 
> Just flagging this up front: the core patch by itself will break some
> drivers, and additional work is required to make them tolerant of the
> new metadata.

May I ask, where is the software plane extension for this feature?
Will you add it for net/sched/act_ct.c?

Adding the hardware offload feature only is a deal breaker IMO.