Re: [dpdk-dev] [RFC] ethdev: add GRE optional fields to flow API

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue, 14 May 2019 10:18:29 +0300
Xiaoyu Min <jackmin@mellanox.com> wrote:

> Add GRE's checksum, key, and sequence field to the
> struct rte_flow_item_gre in order to match.
> 
> Signed-off-by: Xiaoyu Min <jackmin@mellanox.com>
> ---
>  lib/librte_ethdev/rte_flow.h | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h
> index 63f84fca65..fb04af3268 100644
> --- a/lib/librte_ethdev/rte_flow.h
> +++ b/lib/librte_ethdev/rte_flow.h
> @@ -847,6 +847,10 @@ struct rte_flow_item_gre {
>  	 */
>  	rte_be16_t c_rsvd0_ver;
>  	rte_be16_t protocol; /**< Protocol type. */
> +	rte_be16_t checksum; /**< chksum for the header and payload, optional.*/
> +	rte_be16_t rsvd1; /**< present when C bit is set, optional. */
> +	rte_be32_t key; /**< application specific key value, optional. */
> +	rte_be32_t sequence; /**< sequence num for the GRE packet, optional. */
>  };
>  
>  /** Default mask for RTE_FLOW_ITEM_TYPE_GRE. */

This breaks ABI.

To extend you need to add a new flow item type and keep old
one as legacy.