Re: [PATCH iproute2-next v3 0/2] f_flower: match on the number of vlan tags

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue, 26 Apr 2022 12:14:15 +0300
Boris Sukholitko <boris.sukholitko@broadcom.com> wrote:

> Hi,
> 
> Our customers in the fiber telecom world have network configurations
> where they would like to control their traffic according to the number
> of tags appearing in the packet.
> 
> For example, TR247 GPON conformance test suite specification mostly
> talks about untagged, single, double tagged packets and gives lax
> guidelines on the vlan protocol vs. number of vlan tags.
> 
> This is different from the common IT networks where 802.1Q and 802.1ad
> protocols are usually describe single and double tagged packet. GPON
> configurations that we work with have arbitrary mix the above protocols
> and number of vlan tags in the packet.
> 
> The following patch series implement number of vlans flower filter. They
> add num_of_vlans flower filter as an alternative to vlan ethtype protocol
> matching. The end result is that the following command becomes possible:
> 
> tc filter add dev eth1 ingress flower \
>   num_of_vlans 1 vlan_prio 5 action drop
> 
> Also, from our logs, we have redirect rules such that:
> 
> tc filter add dev $GPON ingress flower num_of_vlans $N \
>      action mirred egress redirect dev $DEV
> 
> where N can range from 0 to 3 and $DEV is the function of $N.
> 
> Also there are rules setting skb mark based on the number of vlans:
> 
> tc filter add dev $GPON ingress flower num_of_vlans $N vlan_prio \
>     $P action skbedit mark $M
> 
> Thanks,
> Boris.
> 
> - v3: rebased to the latest iproute2-next
> - v2: add missing f_flower subject prefix
> 
> Boris Sukholitko (2):
>   f_flower: Add num of vlans parameter
>   f_flower: Check args with num_of_vlans
> 
>  tc/f_flower.c | 57 ++++++++++++++++++++++++++++++++++++---------------
>  1 file changed, 41 insertions(+), 16 deletions(-)

Can you do this with BPF? instead of kernel change?