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From:   Yan Zhai <yan@cloudflare.com>
Date:   Thu, 13 Jul 2023 23:27:51 -0500
Message-ID: <CAO3-Pbr8kypYNSJchh3b4KCe4e0XH038BU6YQm3i+u+EHt2iDw@mail.gmail.com>
Subject: Re: [PATCH v2 net] gso: fix dodgy bit handling for GSO_UDP_L4
To:     Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc:     "open list:NETWORKING [TCP]" <netdev@vger.kernel.org>,
        kernel-team@cloudflare.com, Eric Dumazet <edumazet@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        David Ahern <dsahern@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>,
        Xin Long <lucien.xin@gmail.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Andrew Melnychenko <andrew@daynix.com>,
        Jason Wang <jasowang@redhat.com>,
        open list <linux-kernel@vger.kernel.org>,
        "open list:SCTP PROTOCOL" <linux-sctp@vger.kernel.org>
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On Thu, Jul 13, 2023 at 12:38=E2=80=AFPM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Thu, Jul 13, 2023 at 1:28=E2=80=AFPM Yan Zhai <yan@cloudflare.com> wro=
te:
> >
> > Commit 1fd54773c267 ("udp: allow header check for dodgy GSO_UDP_L4
> > packets.") checks DODGY bit for UDP, but for packets that can be fed
> > directly to the device after gso_segs reset, it actually falls through
> > to fragmentation:
> >
> > https://lore.kernel.org/all/CAJPywTKDdjtwkLVUW6LRA2FU912qcDmQOQGt2WaDo2=
8KzYDg+A@mail.gmail.com/
> >
> > This change restores the expected behavior of GSO_UDP_L4 packets.
> >
> > Fixes: 1fd54773c267 ("udp: allow header check for dodgy GSO_UDP_L4 pack=
ets.")
> > Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
> > Signed-off-by: Yan Zhai <yan@cloudflare.com>
>
> Reviewed-by: Willem de Bruijn <willemb@google.com>
>
> for next time: places hyperlinks in the block of tags at the bottom of
> the commit as "Link: ${URL}"

Good to learn, thanks!
--
Yan