Re: [PATCH nf] netfilter: nf_tables: map basechain priority to hardware priority

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Tue, Jul 30, 2019 at 12:54:17PM +0200, Pablo Neira Ayuso wrote:
[...]
> @@ -180,6 +181,29 @@ static int nft_setup_cb_call(struct nft_base_chain *basechain,
>  	return 0;
>  }
>  
> +/* Available priorities for hardware offload range: -8192..8191 */
> +#define NFT_BASECHAIN_OFFLOAD_PRIO_MAX		(SHRT_MAX / 4)
> +#define NFT_BASECHAIN_OFFLOAD_PRIO_MIN		(SHRT_MIN / 4)
> +#define NFT_BASECHAIN_OFFLOAD_PRIO_RANGE	(USHRT_MAX / 4)
> +/* tcf_auto_prio() uses 0xC000 as base, then subtract one for each new chain. */
> +#define NFT_BASECHAIN_OFFLOAD_HW_PRIO_BASE	(0xC000 + 1)
> +
> +u16 nft_chain_offload_priority(struct nft_base_chain *basechain)
> +{
> +	u16 prio;
> +
> +	if (basechain->ops.priority < NFT_BASECHAIN_OFFLOAD_PRIO_MIN ||
> +	    basechain->ops.priority > NFT_BASECHAIN_OFFLOAD_PRIO_MAX)
> +		return 0;
> +
> +	/* map netfilter chain priority to hardware priority. */
> +	prio = basechain->ops.priority +
> +		NFT_BASECHAIN_OFFLOAD_PRIO_MAX +
> +			NFT_BASECHAIN_OFFLOAD_HW_PRIO_BASE;
> +
> +	return prio;

This function should actually return:

        return prio << 16;

> +}
> +
>  static int nft_flow_offload_rule(struct nft_trans *trans,
>  				 enum flow_cls_command command)
>  {