[PATCH] net/mlx5: zero encap UDP csum for IPv4 too

[Suanming Mou]

Hi,

> -----Original Message-----
> From: Bing Zhao <bingz at nvidia.com>
> Sent: Monday, November 13, 2023 3:30 PM
> To: Matan Azrad <matan at nvidia.com>; Slava Ovsiienko
> <viacheslavo at nvidia.com>; Raslan Darawsheh <rasland at nvidia.com>; Suanming
> Mou <suanmingm at nvidia.com>; Ori Kam <orika at nvidia.com>
> Cc: dev at dpdk.org; Eli Britstein <elibr at nvidia.com>; stable at dpdk.org
> Subject: [PATCH] net/mlx5: zero encap UDP csum for IPv4 too
> 
> From: Eli Britstein <elibr at nvidia.com>
> 
> A zero UDP csum indicates it should not be validated by the receiver.
> The HW may not calculate UDP csum after encap.
> 
> The cited commit made sure the UDP csum is zero for UDP over IPv6, mistakenly
> not handling UDP over IPv4. Fix it.
> 
> Fixes: bf1d7d9a033a ("net/mlx5: zero out UDP checksum in encapsulation")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Eli Britstein <elibr at nvidia.com>

Acked-by: Suanming Mou <suanmingm at nvidia.com>

> ---
>  drivers/net/mlx5/mlx5_flow_dv.c | 26 +++++++++++++++-----------
>  1 file changed, 15 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
> index 9753af2cb1..115d730317 100644
> --- a/drivers/net/mlx5/mlx5_flow_dv.c
> +++ b/drivers/net/mlx5/mlx5_flow_dv.c
> @@ -4713,6 +4713,7 @@ flow_dv_zero_encap_udp_csum(void *data, struct
> rte_flow_error *error)  {
>  	struct rte_ether_hdr *eth = NULL;
>  	struct rte_vlan_hdr *vlan = NULL;
> +	struct rte_ipv4_hdr *ipv4 = NULL;
>  	struct rte_ipv6_hdr *ipv6 = NULL;
>  	struct rte_udp_hdr *udp = NULL;
>  	char *next_hdr;
> @@ -4729,24 +4730,27 @@ flow_dv_zero_encap_udp_csum(void *data, struct
> rte_flow_error *error)
>  		next_hdr += sizeof(struct rte_vlan_hdr);
>  	}
> 
> -	/* HW calculates IPv4 csum. no need to proceed */
> -	if (proto == RTE_ETHER_TYPE_IPV4)
> -		return 0;
> -
>  	/* non IPv4/IPv6 header. not supported */
> -	if (proto != RTE_ETHER_TYPE_IPV6) {
> +	if (proto != RTE_ETHER_TYPE_IPV4 && proto != RTE_ETHER_TYPE_IPV6)
> {
>  		return rte_flow_error_set(error, ENOTSUP,
>  					  RTE_FLOW_ERROR_TYPE_ACTION,
>  					  NULL, "Cannot offload non
> IPv4/IPv6");
>  	}
> 
> -	ipv6 = (struct rte_ipv6_hdr *)next_hdr;
> -
> -	/* ignore non UDP */
> -	if (ipv6->proto != IPPROTO_UDP)
> -		return 0;
> +	if (proto == RTE_ETHER_TYPE_IPV4) {
> +		ipv4 = (struct rte_ipv4_hdr *)next_hdr;
> +		/* ignore non UDP */
> +		if (ipv4->next_proto_id != IPPROTO_UDP)
> +			return 0;
> +		udp = (struct rte_udp_hdr *)(ipv4 + 1);
> +	} else {
> +		ipv6 = (struct rte_ipv6_hdr *)next_hdr;
> +		/* ignore non UDP */
> +		if (ipv6->proto != IPPROTO_UDP)
> +			return 0;
> +		udp = (struct rte_udp_hdr *)(ipv6 + 1);
> +	}
> 
> -	udp = (struct rte_udp_hdr *)(ipv6 + 1);
>  	udp->dgram_cksum = 0;
> 
>  	return 0;
> --
> 2.34.1