On 5/18/26 2:27 PM, Robin Jarry wrote:
> This reverts commit 1f250674085aeb4ffd15ac2519a68efc04faf7ac.
>
> rte_net_get_ptype() now uses |= to set the L2 ptype inside the VLAN
> parsing loop. Since pkt_type is already initialized with
> RTE_PTYPE_L2_ETHER (0x1), or-ing it with RTE_PTYPE_L2_ETHER_VLAN (0x6)
> results in RTE_PTYPE_L2_ETHER_QINQ (0x7). This causes single VLAN frames
> to be misidentified as QinQ.
>
> This was detected while testing DPDK 25.11.1 in grout. The net/tap
> driver calls rte_net_get_ptype() in tap_verify_csum() to determine the
> L2 header length. With the wrong ptype, l2_len is set to 22 (ether
> + QinQ = 14 + 8) instead of 18 (ether + VLAN = 14 + 4), shifting the IP
> header pointer by 4 bytes. The checksum is then computed on garbage
> data, causing valid packets to be dropped.
>
> Bugzilla ID: 1941
> Fixes: 1f250674085a ("net: fix packet type for stacked VLAN")
> Cc: [email protected]
> Signed-off-by: Robin Jarry <[email protected]>
> ---
> lib/net/rte_net.c | 29 +++++++++++++++--------------
> 1 file changed, 15 insertions(+), 14 deletions(-)
>
Acked-by: Kevin Traynor <[email protected]>
