[PATCH v2 1/2] net: fix offset calculation for GENEVE packet

[huangdengdui]

I have also found some bugs about the tunnel packet type parsing API[1], including one of the problems fixed by this patch.

[1] https://patchwork.dpdk.org/project/dpdk/list/?series=35233

On 2025/5/21 13:11, skori at marvell.com wrote:
> From: Sunil Kumar Kori <skori at marvell.com>
> 
> While parsing packet headers, offset must be added to get next
> header but for geneve header parsing offset is overwritten.
> Also inner_l2_len is not set in case of geneve packets.
> 
> Fixes: 64ed7f854cf4 ("net: add tunnel packet type parsing")
> 
> Signed-off-by: Sunil Kumar Kori <skori at marvell.com>
> ---
>  lib/net/rte_net.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/net/rte_net.c b/lib/net/rte_net.c
> index be24690fdf..1264f33d61 100644
> --- a/lib/net/rte_net.c
> +++ b/lib/net/rte_net.c
> @@ -251,7 +251,8 @@ ptype_tunnel_with_udp(uint16_t *proto, const struct rte_mbuf *m,
>  		if (unlikely(gnh == NULL))
>  			return 0;
>  		geneve_len = sizeof(*gnh) + gnh->opt_len * 4;
> -		*off = geneve_len;
> +		*off += geneve_len;
> +		hdr_lens->inner_l2_len = sizeof(struct rte_udp_hdr) + geneve_len;

The l2_len in mbuf is also calculated from the outer L4 header, so it is calculated in the same way here.
However, this is easy to be misunderstood, can we add a note to inner_l2_len as follows?

struct rte_net_hdr_lens {
	uint8_t l2_len;
	/* Outer_L4_len + ... + inner L2_len for tunneling pkt. */
	uint8_t inner_l2_len;
	uint16_t l3_len;
	uint16_t inner_l3_len;
	uint16_t tunnel_len;
	uint8_t l4_len;
	uint8_t inner_l4_len;
};


>  		*proto = gnh->proto;
>  		if (gnh->proto == 0)
>  			*proto = rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV4);