net/mlx5: fix LRO checksum completence

  The TCP checksum includes IPV4 pseudo-header checksum and L3
payload checksum which include TCP header and TCP payload.
When mlx5 LRO is enabled, HW will calculate the TCP payload
checksum, PMD need complete the IPV4 pseudo-header checksum
and the TCP header checksum.

The mlx5_lro_update_tcp_hdr function completes the TCP header
checksum, but this function using lower 4 bits of data-offset
field in TCP header to get the whole TCP header length, this
will cause TCP header checksum wrong calculation.

Update the code using higher 4 bits of data-offset field
instead of lower 4 bits.

Fixes: e4c2a16eb1de ("net/mlx5: handle LRO packets in Rx queue")
Cc: stable@dpdk.org

Signed-off-by: Bill Zhou <dongz@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
  

Hi,

> -----Original Message-----
> From: Bill Zhou <dongz@mellanox.com>
> Sent: Friday, June 12, 2020 11:58 AM
> To: dev@dpdk.org
> Cc: stable@dpdk.org; Raslan Darawsheh <rasland@mellanox.com>; Matan
> Azrad <matan@mellanox.com>
> Subject: [PATCH] net/mlx5: fix LRO checksum completence
> 
> The TCP checksum includes IPV4 pseudo-header checksum and L3
> payload checksum which include TCP header and TCP payload.
> When mlx5 LRO is enabled, HW will calculate the TCP payload
> checksum, PMD need complete the IPV4 pseudo-header checksum
> and the TCP header checksum.
> 
> The mlx5_lro_update_tcp_hdr function completes the TCP header
> checksum, but this function using lower 4 bits of data-offset
> field in TCP header to get the whole TCP header length, this
> will cause TCP header checksum wrong calculation.
> 
> Update the code using higher 4 bits of data-offset field
> instead of lower 4 bits.
> 
> Fixes: e4c2a16eb1de ("net/mlx5: handle LRO packets in Rx queue")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Bill Zhou <dongz@mellanox.com>
> Acked-by: Matan Azrad <matan@mellanox.com>
> ---
>  drivers/net/mlx5/mlx5_rxtx.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
> index 6a17a9a5d0..e4c1c95b0e 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.c
> +++ b/drivers/net/mlx5/mlx5_rxtx.c
> @@ -1529,7 +1529,7 @@ mlx5_lro_update_tcp_hdr(struct rte_tcp_hdr
> *restrict tcp,
>  	if (cqe->lro_tcppsh_abort_dupack & MLX5_CQE_LRO_PUSH_MASK)
>  		tcp->tcp_flags |= RTE_TCP_PSH_FLAG;
>  	tcp->cksum = 0;
> -	csum += rte_raw_cksum(tcp, (tcp->data_off & 0xF) * 4);
> +	csum += rte_raw_cksum(tcp, (tcp->data_off >> 4) * 4);
>  	csum = ((csum & 0xffff0000) >> 16) + (csum & 0xffff);
>  	csum = (~csum) & 0xffff;
>  	if (csum == 0)
> --
> 2.21.0


Patch applied to next-net-mlx,

Kindest regards,
Raslan Darawsheh