Re: [dpdk-dev] [PATCH v2 1/4] ethdev: allow negative values in flow rule types

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 9/8/20 11:15 PM, Gregory Etelson wrote:
> From: Gregory Etelson <getelson@mellanox.com>
> 
> RTE flow items & actions use positive values in item & action type.
> Negative values are reserved for PMD private types. PMD
> items & actions usually are not exposed to application and are not
> used to create RTE flows.
> 
> The patch allows applications with access to PMD flow
> items & actions ability to integrate RTE and PMD items & actions
> and use them to create flow rule.
> 
> RTE flow library functions cannot work with PMD private items and
> actions (elements) because RTE flow has no API to query PMD flow
> object size. In the patch, PMD flow elements use object pointer.
> RTE flow library functions handle PMD element object size as
> size of a pointer. PMD handles its objects internally.
> 
> Signed-off-by: Gregory Etelson <getelson@mellanox.com>
> Acked-by: Ori Kam <orika@mellanox.com>
> ---
> v2:
> * Update commit log
> ---
>  lib/librte_ethdev/rte_flow.c | 30 ++++++++++++++++++++++++------
>  1 file changed, 24 insertions(+), 6 deletions(-)
> 
> diff --git a/lib/librte_ethdev/rte_flow.c b/lib/librte_ethdev/rte_flow.c
> index f8fdd68fe9..9905426bc9 100644
> --- a/lib/librte_ethdev/rte_flow.c
> +++ b/lib/librte_ethdev/rte_flow.c
> @@ -564,7 +564,12 @@ rte_flow_conv_item_spec(void *buf, const size_t size,
>  		}
>  		break;
>  	default:
> -		off = rte_flow_desc_item[item->type].size;
> +		/**
> +		 * allow PMD private flow item
> +		 */
> +		off = (uint32_t)item->type <= INT_MAX ?

It looks inconsistent to cast to uint32_t and compare vs
INT_MAX. It should be either cast to 'unsigned int' or
compare vs INT32_MAX. I think cast to 'unsigned int' is
better for 'enum' values.
But may be it should be 'int' and < 0 in fact to match
the description that negative values are vendor-specific.

> +			rte_flow_desc_item[item->type].size :
> +			sizeof(void *);
>  		rte_memcpy(buf, data, (size > off ? off : size));
>  		break;
>  	}
> @@ -667,7 +672,12 @@ rte_flow_conv_action_conf(void *buf, const size_t size,
>  		}
>  		break;
>  	default:
> -		off = rte_flow_desc_action[action->type].size;
> +		/**
> +		 * allow PMD private flow action
> +		 */
> +		off = (uint32_t)action->type <= INT_MAX ?

Same

> +			rte_flow_desc_action[action->type].size :
> +			sizeof(void *);
>  		rte_memcpy(buf, action->conf, (size > off ? off : size));
>  		break;
>  	}
> @@ -709,8 +719,12 @@ rte_flow_conv_pattern(struct rte_flow_item *dst,
>  	unsigned int i;
>  
>  	for (i = 0, off = 0; !num || i != num; ++i, ++src, ++dst) {
> -		if ((size_t)src->type >= RTE_DIM(rte_flow_desc_item) ||
> -		    !rte_flow_desc_item[src->type].name)
> +		/**
> +		 * allow PMD private flow item
> +		 */
> +		if (((uint32_t)src->type <= INT_MAX) &&

Same

> +			((size_t)src->type >= RTE_DIM(rte_flow_desc_item) ||
> +		    !rte_flow_desc_item[src->type].name))
>  			return rte_flow_error_set
>  				(error, ENOTSUP, RTE_FLOW_ERROR_TYPE_ITEM, src,
>  				 "cannot convert unknown item type");
> @@ -798,8 +812,12 @@ rte_flow_conv_actions(struct rte_flow_action *dst,
>  	unsigned int i;
>  
>  	for (i = 0, off = 0; !num || i != num; ++i, ++src, ++dst) {
> -		if ((size_t)src->type >= RTE_DIM(rte_flow_desc_action) ||
> -		    !rte_flow_desc_action[src->type].name)
> +		/**
> +		 * allow PMD private flow action
> +		 */
> +		if (((uint32_t)src->type <= INT_MAX) &&

Same

> +		    ((size_t)src->type >= RTE_DIM(rte_flow_desc_action) ||
> +		    !rte_flow_desc_action[src->type].name))
>  			return rte_flow_error_set
>  				(error, ENOTSUP, RTE_FLOW_ERROR_TYPE_ACTION,
>  				 src, "cannot convert unknown action type");
>