Subject: Re: [PATCH iwl-net] igc: Check VLAN EtherType mask

From: Vinicius Costa Gomes <[email-masked]>
Date: Wed, 06 Dec 2023 17:26:05 -0800

Kurt Kanzenbach <[email-masked]> writes:

> Currently the driver accepts VLAN EtherType steering rules regardless of
> the configured mask. And things might fail silently or with confusing error
> messages to the user. The VLAN EtherType can only be matched by full
> mask. Therefore, add a check for that.
>
> For instance the following rule is invalid, but the driver accepts it and
> ignores the user specified mask:
> |root@host:~# ethtool -N enp3s0 flow-type ether vlan-etype 0x8100 \
> |             m 0x00ff action 0
> |Added rule with ID 63
> |root@host:~# ethtool --show-ntuple enp3s0
> |4 RX rings available
> |Total 1 rules
> |
> |Filter: 63
> |        Flow Type: Raw Ethernet
> |        Src MAC addr: 00:00:00:00:00:00 mask: FF:FF:FF:FF:FF:FF
> |        Dest MAC addr: 00:00:00:00:00:00 mask: FF:FF:FF:FF:FF:FF
> |        Ethertype: 0x0 mask: 0xFFFF
> |        VLAN EtherType: 0x8100 mask: 0x0
> |        VLAN: 0x0 mask: 0xffff
> |        User-defined: 0x0 mask: 0xffffffffffffffff
> |        Action: Direct to queue 0
>
> After:
> |root@host:~# ethtool -N enp3s0 flow-type ether vlan-etype 0x8100 \
> |             m 0x00ff action 0
> |rmgr: Cannot insert RX class rule: Operation not supported
>
> Fixes: 2b477d057e33 ("igc: Integrate flex filter into ethtool ops")
> Suggested-by: Suman Ghosh <[email-masked]>
> Signed-off-by: Kurt Kanzenbach <[email-masked]>
> ---

I was just wondering if an alternative would be to use flex filters for
matching vlan-etype with a partial mask. But I don't think there's any
real use case for partial masks, better to reject them:

Acked-by: Vinicius Costa Gomes <[email-masked]>

Cheers,
-- 
Vinicius