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From:   Eyal Birger <eyal.birger@gmail.com>
Date:   Mon, 27 Feb 2023 11:30:34 +0200
Message-ID: <CAHsH6GtArNCyA3UAJbSYYD86fb2QxskbSoNQo2RVHQzKC643zg@mail.gmail.com>
Subject: Re: [PATCH v2 0/1] net: geneve: accept every ethertype
To:     Josef Miegl <josef@miegl.cz>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
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Hi,

On Mon, Feb 27, 2023 at 10:19=E2=80=AFAM Josef Miegl <josef@miegl.cz> wrote=
:
>
> The Geneve encapsulation, as defined in RFC 8926, has a Protocol Type
> field, which states the Ethertype of the payload appearing after the
> Geneve header.
>
> Commit 435fe1c0c1f7 ("net: geneve: support IPv4/IPv6 as inner protocol")
> introduced a new IFLA_GENEVE_INNER_PROTO_INHERIT flag that allowed the
> use of other Ethertypes than Ethernet. However, for a reason not known
> to me, it imposed a restriction that prohibits receiving payloads other
> than IPv4, IPv6 and Ethernet.

FWIW I added support for IPv4/IPv6 because these are the use cases I had
and could validate. I don't know what problems could arise from supporting
all possible ethertypes and can't test that.

>
> This patch removes this restriction, making it possible to receive any
> Ethertype as a payload, if the IFLA_GENEVE_INNER_PROTO_INHERIT flag is
> set.

This seems like an addition not a bugfix so personally seems like it should
be targeting net-next (which is currently closed afaik).

Eyal.

>
> This is especially useful if one wants to encapsulate MPLS, because with
> this patch the control-plane traffic (IP, LLC) and the data-plane
> traffic (MPLS) can be encapsulated without an Ethernet frame, making
> lightweight overlay networks a possibility.
>
> Changes in v2:
>   - added a cover letter
>   - lines no longer exceed 80 columns
>
>
> Josef Miegl (1):
>   net: geneve: accept every ethertype
>
>  drivers/net/geneve.c | 15 ++++-----------
>  1 file changed, 4 insertions(+), 11 deletions(-)
>
> --
> 2.37.1
>