netdev - Re: [PATCH bpf 0/3] Fix csum unnecessary on bpf_skb_adjust

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Date:   Tue, 2 Jun 2020 16:19:34 +0100
From:   Lorenz Bauer <lmb@...udflare.com>
To:     Daniel Borkmann <daniel@...earbox.net>
Cc:     Alexei Starovoitov <alexei.starovoitov@...il.com>,
        Alan Maguire <alan.maguire@...cle.com>,
        bpf <bpf@...r.kernel.org>, Networking <netdev@...r.kernel.org>
Subject: Re: [PATCH bpf 0/3] Fix csum unnecessary on bpf_skb_adjust_room

On Tue, 2 Jun 2020 at 15:58, Daniel Borkmann <daniel@...earbox.net> wrote:
>
> This series fixes an issue originally reported by Lorenz Bauer where using
> the bpf_skb_adjust_room() helper hid a checksum bug since it wasn't adjusting
> CHECKSUM_UNNECESSARY's skb->csum_level after decap. The fix is two-fold:
>  i) We do a safe reset in bpf_skb_adjust_room() to CHECKSUM_NONE with an opt-
>     out flag BPF_F_ADJ_ROOM_NO_CSUM_RESET.
> ii) We add a new bpf_csum_level() for the latter in order to allow users to
>     manually inc/dec the skb->csum_level when needed.
> The series is rebased against latest bpf-next tree. It can be applied there,
> or to bpf after the merge win sync from net-next.
>
> Thanks!
>
> Daniel Borkmann (3):
>   bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
>   bpf: add csum_level helper for fixing up csum levels
>   bpf, selftests: adapt cls_redirect to call csum_level helper
>
>  include/linux/skbuff.h                        |  8 +++
>  include/uapi/linux/bpf.h                      | 51 ++++++++++++++++++-
>  net/core/filter.c                             | 46 ++++++++++++++++-
>  tools/include/uapi/linux/bpf.h                | 51 ++++++++++++++++++-
>  .../selftests/bpf/progs/test_cls_redirect.c   |  9 ++--
>  5 files changed, 158 insertions(+), 7 deletions(-)
>
> --
> 2.21.0
>

Thanks for pushing this out, Daniel!

-- 
Lorenz Bauer  |  Systems Engineer
6th Floor, County Hall/The Riverside Building, SE1 7PB, UK

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