Re: [PATCH v2] net: fix parsing of frames with arbitrary VLAN stacks

[Thomas Monjalon <thomas@monjalon.net>]

15/01/2026 14:14, Gregory Etelson:
> The rte_net_get_ptype() supported only 2 types of VLAN headers frames
> that are defined in the IEEE standards 802.1Q and 802.1ad:
> 
> frames with a single 0x8100 VLAN header:
>   eth type VLAN / vlan / [IPv4 | IPv6 ]
> 
> frames with 0x88A8 QinQ header followed by 0x8100 VLAN:
>  eth type QinQ / vlan type VLAN / vlan / [IPv4 | IPv6 ]
> 
> The function did not parse frames where VLAN headers were stacked in
> different configurations.
> Such frames should also be allowed to provide HW vendor flexibility.
> As a result, ptype bitmask and header length returned from
> rte_net_get_ptype() for a custom VLAN frame were wrong.
> 
> For example, the parser result for the frame
>   eth type QinQ / vlan type QinQ / vlan type VLAN / vlan / ipv4
> was:
> pkt_type:=0x120007
>    RTE_PTYPE_L2_ETHER_QINQ         0x00000007 OK
>    RTE_PTYPE_INNER_L2_ETHER_VLAN   0x00020000 wrong
>    RTE_PTYPE_INNER_L3_IPV4         0x00100000 wrong
> 
> hdr_lens:={
>   l2_len       = 22 wrong
>   inner_l2_len =  4 wrong
>   l3_len       =  0 wrong
>   inner_l3_len = 20 wrong
> }
> 
> The patch changes:
> 1. Allow frames with up to RTE_NET_VLAN_MAX_DEPTH:=8
>    number of VLAN headers.
> 
> 2. Set each parsed VLAN type in the returned ptype bitmask.
>    Multiple VLAN headers are referenced by a single
>    RTE_PTYPE_L2_ETHER_VLAN bit.
>    Multiple QinQ headers are references by a single
>    RTE_PTYPE_L2_ETHER_QINQ bit.
> 
> 3. Preserve RTE_PTYPE_L2_ETHER bit if VLAN or QinQ type was detected.
> 
> Fixes: eb173c8def0a ("net: support VLAN in software packet type parser")
> Fixes: 218a163efd67 ("net: support QinQ in software packet type parser")
> 
> Cc: stable@dpdk.org
> 
> Signed-off-by: Gregory Etelson <getelson@nvidia.com>

There's no ack, probably because the parsing code looks complex.
v1 was sent in November with a review helped by AI.
v2 solves the only issue found.
So it's time to merge.

Applied, thanks.