Looks good to me.

On 3/10/2022 7:50 PM, Gregory Etelson wrote:
> GTP header can be followed by an optional 32 bits extension.
> GTP notifies about the extension presence through the E, S or PN
> header bits.
>
> Csum GTP header parser did not check the extension bits value.
>
> The patch updates GTP header length if header extension bits are set.
Can we rephrase above line "if at-least one of the extension bit is set."
To make it more clear.
>
> Cc:stable@dpdk.org
>
> Fixes: d8e5e69f3a9b ("app/testpmd: add GTP parsing and Tx checksum offload")
> Signed-off-by: Gregory Etelson<getelson@nvidia.com>
Acked-by: Aman Singh <aman.deep.singh@intel.com>
> ---
>   app/test-pmd/csumonly.c | 7 +++----
>   1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c
> index 5274d498ee..f8abcded2b 100644
> --- a/app/test-pmd/csumonly.c
> +++ b/app/test-pmd/csumonly.c
> @@ -223,15 +223,14 @@ parse_gtp(struct rte_udp_hdr *udp_hdr,
>   
>   	gtp_hdr = (struct rte_gtp_hdr *)((char *)udp_hdr +
>   		  sizeof(struct rte_udp_hdr));
> -
> +	if (gtp_hdr->e || gtp_hdr->s || gtp_hdr->pn)
> +		gtp_len += sizeof(struct rte_gtp_hdr_ext_word);
>   	/*
>   	 * Check message type. If message type is 0xff, it is
>   	 * a GTP data packet. If not, it is a GTP control packet
>   	 */
>   	if (gtp_hdr->msg_type == 0xff) {
> -		ip_ver = *(uint8_t *)((char *)udp_hdr +
> -			 sizeof(struct rte_udp_hdr) +
> -			 sizeof(struct rte_gtp_hdr));
> +		ip_ver = *(uint8_t *)((char *)gtp_hdr + gtp_len);
>   		ip_ver = (ip_ver) & 0xf0;
>   
>   		if (ip_ver == RTE_GTP_TYPE_IPV4) {