Subject: Re: [PATCH net-next v1 1/7] net: flow_offload: provision conntrack info in ct_metadata

From: Simon Horman <[email-masked]>
Date: Fri, 13 Jan 2023 10:12:38 +0100

+ Baowen Zheng, [email-masked]

On Tue, Jan 10, 2023 at 02:30:17PM +0100, Vlad Buslov wrote:
> In order to offload connections in other states besides "established" the
> driver offload callbacks need to have access to connection conntrack info.
> Extend flow offload intermediate representation data structure
> flow_action_entry->ct_metadata with new enum ip_conntrack_info field and
> fill it in tcf_ct_flow_table_add_action_meta() callback.
> 
> Reject offloading IP_CT_NEW connections for now by returning an error in
> relevant driver callbacks based on value of ctinfo. Support for offloading
> such connections will need to be added to the drivers afterwards.
> 
> Signed-off-by: Vlad Buslov <[email-masked]>
> ---

...

> diff --git a/drivers/net/ethernet/netronome/nfp/flower/conntrack.c b/drivers/net/ethernet/netronome/nfp/flower/conntrack.c
> index f693119541d5..2c550a1792b7 100644
> --- a/drivers/net/ethernet/netronome/nfp/flower/conntrack.c
> +++ b/drivers/net/ethernet/netronome/nfp/flower/conntrack.c
> @@ -1964,6 +1964,23 @@ int nfp_fl_ct_stats(struct flow_cls_offload *flow,
>  	return 0;
>  }
>  
> +static bool
> +nfp_fl_ct_offload_supported(struct flow_cls_offload *flow)
> +{
> +	struct flow_rule *flow_rule = flow->rule;
> +	struct flow_action *flow_action =
> +		&flow_rule->action;
> +	struct flow_action_entry *act;
> +	int i;
> +
> +	flow_action_for_each(i, act, flow_action) {
> +		if (act->id == FLOW_ACTION_CT_METADATA)
> +			return act->ct_metadata.ctinfo != IP_CT_NEW;
> +	}
> +
> +	return false;
> +}
> +

Hi Vlad,

Some feedback from Baowen Zheng, who asked me to pass it on here:

  It is confusing that after FLOW_ACTION_CT_METADATA check, this functoin
  will return false, that is -EOPNOTSUPP.

  Since this function is only used to check nft table, It seems better to
  change its name to nfp_fl_ct_offload_nft_supported(). This would make things
  clearer and may avoid it being used in the wrong way.

...