Re: [PATCH] app/testpmd: add ipv6 extension header parse

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 8 Jan 2025 10:46:32 +0800
Jie Hai <haijie1@huawei.com> wrote:

> From: Jie Hai <haijie1@huawei.com>
> To: <dev@dpdk.org>, <thomas@monjalon.net>, <ferruh.yigit@amd.com>, Aman Singh  <aman.deep.singh@intel.com>
> CC: <lihuisong@huawei.com>, <fengcengwen@huawei.com>, <haijie1@huawei.com>,  <huangdengdui@huawei.com>
> Subject: [PATCH] app/testpmd: add ipv6 extension header parse
> Date: Wed, 8 Jan 2025 10:46:32 +0800
> X-Mailer: git-send-email 2.22.0
> 
> This patch support parse ipv6 extension header, and
> support TSO for ipv6tcp packets with extension header.
> 
> Signed-off-by: Jie Hai <haijie1@huawei.com>
> ---
>  app/test-pmd/csumonly.c | 47 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 46 insertions(+), 1 deletion(-)
> 
> diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c
> index 2246c22e8e56..a7b11490fe27 100644
> --- a/app/test-pmd/csumonly.c
> +++ b/app/test-pmd/csumonly.c
> @@ -124,14 +124,59 @@ parse_ipv4(struct rte_ipv4_hdr *ipv4_hdr, struct testpmd_offload_info *info)
>  		info->l4_len = 0;
>  }
>  
> +static uint16_t
> +parse_ipv6_ext(struct rte_ipv6_hdr *ipv6_hdr, uint32_t *off)
> +{
> +	struct ext_hdr {
> +		uint8_t next_hdr;
> +		uint8_t len;
> +	};
> +	struct ext_hdr *xh;
> +	uint16_t proto;
> +	char *xh_fst;
> +	uint16_t i;
> +
> +	proto = ipv6_hdr->proto;
> +	xh_fst = (char *)ipv6_hdr + sizeof(*ipv6_hdr);
> +#define MAX_EXT_HDRS 9
> +	for (i = 0; i < MAX_EXT_HDRS; i++) {
> +		switch (proto) {
> +		case IPPROTO_HOPOPTS:
> +		case IPPROTO_ROUTING:
> +		case IPPROTO_DSTOPTS:
> +			xh = (struct ext_hdr *)(xh_fst + *off);
> +			*off += (xh->len + 1) * 8;
> +			proto = xh->next_hdr;
> +			break;
> +		case IPPROTO_AH:
> +			xh = (struct ext_hdr *)(xh_fst + *off);
> +			*off += (xh->len + 2) * 4;
> +			proto = xh->next_hdr;
> +			break;
> +		case IPPROTO_FRAGMENT:
> +			xh = (struct ext_hdr *)(xh_fst + *off);
> +			*off += 8;
> +			proto = xh->next_hdr;
> +			return proto; /* this is always the last ext hdr */
> +		case IPPROTO_NONE:
> +			return proto;
> +		default:
> +			return proto;
> +		}
> +	}
> +	return proto;
> +}
> +

Why copy/paste of rte_net_skip_ip6_ext, why not use that?
Having two copies of same codes means that bugs need to be fixed in two places later.