Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <a9109da1-ba49-d8f4-1315-278e5c890b99@nbd.name>
Date:   Tue, 8 Nov 2022 10:46:54 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0)
 Gecko/20100101 Thunderbird/102.3.2
Content-Language: en-US
To:     Vladimir Oltean <olteanv@gmail.com>
Cc:     netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, linux-kernel@vger.kernel.org
References: <20221107185452.90711-1-nbd@nbd.name>
 <20221107185452.90711-8-nbd@nbd.name> <20221107215745.ascdvnxqrbw4meuv@skbuf>
 <3b275dda-39ac-282d-8a46-d3a95fdfc766@nbd.name>
 <20221108090039.imamht5iyh2bbbnl@skbuf>
 <0948d841-b0eb-8281-455a-92f44586e0c0@nbd.name>
 <20221108094018.6cspe3mkh3hakxpd@skbuf>
From:   Felix Fietkau <nbd@nbd.name>
Subject: Re: [PATCH 08/14] net: vlan: remove invalid VLAN protocol warning
In-Reply-To: <20221108094018.6cspe3mkh3hakxpd@skbuf>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 08.11.22 10:40, Vladimir Oltean wrote:
> On Tue, Nov 08, 2022 at 10:20:44AM +0100, Felix Fietkau wrote:
>> I need to look into how METADATA_HW_PORT_MUX works, but I think it could
>> work.
> 
> Could you please coordinate with Maxime to come up with something
> common? Currently he proposes a generic "oob" tagger, while you propose
> that we stay with the "mtk"/"qca" taggers, but they are taught to look
> after offloaded metadata rather than in the packet. IMO your proposal
> sounds better; the name of the tagging protocol is already exposed to
> user space via /sys/class/net/<dsa-master>/dsa/tagging and therefore ABI.
> It's just that we need a way to figure out how to make the flow
> dissector and other layers not adjust for DSA header length if the DSA
> tag is offloaded and not present in the packet.
I think it depends on the hardware. If you can rely on the hardware 
always reporting the port out-of-band, a generic "oob" tagger would be 
fine.
In my case, it depends on whether a second non-DSA ethernet MAC is 
active on the same device, so I do need to continue using the "mtk" tag 
driver.
The flow dissector part is already solved: I simply used the existing 
.flow_dissect() tag op.

- Felix