Re: [dpdk-dev] [PATCH 01/10] ethdev: reuse header definition in flow pattern item ETH

[Ori Kam <orika@nvidia.com>]

Hi Ivan,

> -----Original Message-----
> From: Ivan Malov <ivan.malov@oktetlabs.ru>
> Sent: Friday, March 12, 2021 11:32 AM
> 
> One ought to reuse existing header structs in flow items.
> This particular item contains non-header fields, so it's
> important to keep the header fields in a separate struct.
> 
> Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
> Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> Reviewed-by: Andy Moreton <amoreton@xilinx.com>
> ---
>  lib/librte_ethdev/rte_flow.h | 44 ++++++++++++++++++++++--------------
>  1 file changed, 27 insertions(+), 17 deletions(-)
> 
> diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h
> index 669e677e9..96fd93ee1 100644
> --- a/lib/librte_ethdev/rte_flow.h
> +++ b/lib/librte_ethdev/rte_flow.h
> @@ -728,22 +728,32 @@ static const struct rte_flow_item_raw
> rte_flow_item_raw_mask = {
>   *
>   * Matches an Ethernet header.
>   *
> - * The @p type field either stands for "EtherType" or "TPID" when followed
> - * by so-called layer 2.5 pattern items such as RTE_FLOW_ITEM_TYPE_VLAN.
> In
> - * the latter case, @p type refers to that of the outer header, with the
> - * inner EtherType/TPID provided by the subsequent pattern item. This is the
> - * same order as on the wire.
> - * If the @p type field contains a TPID value, then only tagged packets with the
> - * specified TPID will match the pattern.
> - * The field @p has_vlan can be used to match any type of tagged packets,
> - * instead of using the @p type field.
> - * If the @p type and @p has_vlan fields are not specified, then both tagged
> - * and untagged packets will match the pattern.
> + * Inside @p hdr field, the sub-field @p ether_type stands either for EtherType
> + * or TPID, depending on whether the item is followed by a VLAN item or not.
> If
> + * two VLAN items follow, the sub-field refers to the outer one, which, in turn,
> + * contains the inner TPID in the similar header field. The innermost VLAN
> item
> + * contains a layer-3 EtherType. All of that follows the order seen on the wire.
> + *
> + * If the field in question contains a TPID value, only tagged packets with the
> + * specified TPID will match the pattern. Alternatively, it's possible to match
> + * any type of tagged packets by means of the field @p has_vlan rather than
> use
> + * the EtherType/TPID field. Also, it's possible to leave the two fields unused.
> + * If this is the case, both tagged and untagged packets will match the pattern.
>   */
> +RTE_STD_C11
>  struct rte_flow_item_eth {
> -	struct rte_ether_addr dst; /**< Destination MAC. */
> -	struct rte_ether_addr src; /**< Source MAC. */
> -	rte_be16_t type; /**< EtherType or TPID. */
> +	union {
> +		struct {
> +			/*
> +			 * These fields are retained for compatibility.
> +			 * Please switch to the new header field below.
> +			 */
> +			struct rte_ether_addr dst; /**< Destination MAC. */
> +			struct rte_ether_addr src; /**< Source MAC. */
> +			rte_be16_t type; /**< EtherType or TPID. */
> +		};
> +		struct rte_ether_hdr hdr;
> +	};
>  	uint32_t has_vlan:1; /**< Packet header contains at least one VLAN. */
>  	uint32_t reserved:31; /**< Reserved, must be zero. */
>  };
> @@ -751,9 +761,9 @@ struct rte_flow_item_eth {
>  /** Default mask for RTE_FLOW_ITEM_TYPE_ETH. */
>  #ifndef __cplusplus
>  static const struct rte_flow_item_eth rte_flow_item_eth_mask = {
> -	.dst.addr_bytes = "\xff\xff\xff\xff\xff\xff",
> -	.src.addr_bytes = "\xff\xff\xff\xff\xff\xff",
> -	.type = RTE_BE16(0x0000),
> +	.hdr.d_addr.addr_bytes = "\xff\xff\xff\xff\xff\xff",
> +	.hdr.s_addr.addr_bytes = "\xff\xff\xff\xff\xff\xff",
> +	.hdr.ether_type = RTE_BE16(0x0000),
>  };
>  #endif
> 
> --
> 2.20.1

Acked-by: Ori Kam <orika@nvidia.com>
Best,
Ori