On Mon, 18 May 2026 at 15:27, Robin Jarry <[email protected]> wrote:
>
> The VLAN and QinQ code paths in rte_net_get_ptype handle at most two
> tags with duplicated logic. Replace them with a single loop that
> consumes all consecutive VLAN/QinQ headers regardless of depth.
>
> Bugzilla ID: 1941
> Suggested-by: David Marchand <[email protected]>
> Signed-off-by: Robin Jarry <[email protected]>

For the record, I am still skeptical about the usecase behind this change.


> ---
>  lib/net/rte_net.c | 35 ++++++++++++++++-------------------
>  1 file changed, 16 insertions(+), 19 deletions(-)
>
> diff --git a/lib/net/rte_net.c b/lib/net/rte_net.c
> index c70b57fdc0f8..d3cded961fb5 100644
> --- a/lib/net/rte_net.c
> +++ b/lib/net/rte_net.c
> @@ -349,29 +349,26 @@ uint32_t rte_net_get_ptype(const struct rte_mbuf *m,
>         if (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV4))
>                 goto l3; /* fast path if packet is IPv4 */
>
> -       if (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_VLAN)) {
> +       if ((proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_VLAN)) ||
> +               (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_QINQ))) {
>                 const struct rte_vlan_hdr *vh;
>                 struct rte_vlan_hdr vh_copy;
>
> -               pkt_type = RTE_PTYPE_L2_ETHER_VLAN;
> -               vh = rte_pktmbuf_read(m, off, sizeof(*vh), &vh_copy);
> -               if (unlikely(vh == NULL))
> -                       return pkt_type;
> -               off += sizeof(*vh);
> -               hdr_lens->l2_len += sizeof(*vh);
> -               proto = vh->eth_proto;
> -       } else if (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_QINQ)) {
> -               const struct rte_vlan_hdr *vh;
> -               struct rte_vlan_hdr vh_copy;
> +               if (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_VLAN))
> +                       pkt_type = RTE_PTYPE_L2_ETHER_VLAN;
> +               else
> +                       pkt_type = RTE_PTYPE_L2_ETHER_QINQ;
> +
> +               do {
> +                       vh = rte_pktmbuf_read(m, off, sizeof(*vh), &vh_copy);
> +                       if (unlikely(vh == NULL))
> +                               return pkt_type;

Kevin noted that it is weird to report back some packet type when the
packet is malformed.
Maybe return RTE_PTYPE_UNKNOWN here so that the application is forced
to validate the packet? (it should already be doing it, in any
case..).


> +                       off += sizeof(*vh);
> +                       hdr_lens->l2_len += sizeof(*vh);
> +                       proto = vh->eth_proto;
> +               } while (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_VLAN) ||
> +                       proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_QINQ));
>
> -               pkt_type = RTE_PTYPE_L2_ETHER_QINQ;
> -               vh = rte_pktmbuf_read(m, off + sizeof(*vh), sizeof(*vh),
> -                       &vh_copy);
> -               if (unlikely(vh == NULL))
> -                       return pkt_type;
> -               off += 2 * sizeof(*vh);
> -               hdr_lens->l2_len += 2 * sizeof(*vh);
> -               proto = vh->eth_proto;
>         } else if ((proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_MPLS)) ||
>                 (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_MPLSM))) {
>                 unsigned int i;


-- 
David Marchand

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