[PATCH] gro: fix the chain index in insert_new_item for more than 2 packets

[Hu, Jiayu]

> -----Original Message-----
> From: Kumara Parameshwaran <kumaraparamesh92 at gmail.com>
> Sent: Wednesday, September 7, 2022 5:32 PM
> To: Hu, Jiayu <jiayu.hu at intel.com>
> Cc: dev at dpdk.org; Kumara Parameshwaran
> <kumaraparamesh92 at gmail.com>
> Subject: [PATCH] gro: fix the chain index in insert_new_item for more than 2
> packets
> 
> From: Kumara Parameshwaran <kumaraparamesh92 at gmail.com>
> 
> When more than two packets are merged in a flow, and if we receive a 3rd
> packet which is matching the sequence of the 2nd packet the prev_idx will
> be 1 and not 2, hence resulting in packet re-ordering
> 
> Signed-off-by: Kumara Parameshwaran <kumaraparamesh92 at gmail.com>
> ---
> V1:
> 	Initial changes to fix packet reordering issue when
> 	more than 2 items are chained in a flow.
> 	Ex:
> 		3 mergeable TCP packets received in order.
> 		packet_0 - no flow found so insert the packet and new start
> 		index -> 0
> 		packet_1-> flow found. prev_idx, curr_index = 0. So merge
> works
> 		find packet_0->packet_1
> 		packet_2 flow found. prev_indx =0, curr_index = 1. Matching
> 		dequence numbers found but chained as
> 		packet_0->packet_2->packet_1
> 
>  lib/gro/gro_tcp4.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/gro/gro_tcp4.c b/lib/gro/gro_tcp4.c index
> 7498c66141..9758e28fd5 100644
> --- a/lib/gro/gro_tcp4.c
> +++ b/lib/gro/gro_tcp4.c
> @@ -305,7 +305,7 @@ gro_tcp4_reassemble(struct rte_mbuf *pkt,
>  			 * length is greater than the max value. Store
>  			 * the packet into the flow.
>  			 */
> -			if (insert_new_item(tbl, pkt, start_time, prev_idx,
> +			if (insert_new_item(tbl, pkt, start_time, cur_idx,
>  						sent_seq, ip_id, is_atomic)

Good catch.

Acked-by: Jiayu Hu <Jiayu.hu at intel.com>

Thanks,
Jiayu
> ==
>  					INVALID_ARRAY_INDEX)
>  				return -1;
> --
> 2.25.1