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References: <20231129165721.337302-1-dima@arista.com> <20231129165721.337302-3-dima@arista.com>
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From:   Eric Dumazet <edumazet@google.com>
Date:   Wed, 29 Nov 2023 18:02:03 +0100
Message-ID: <CANn89iLr53_W2183MU97Eqd9A4sZp7M_kEB79sLp+1pPa7pFcA@mail.gmail.com>
Subject: Re: [PATCH v4 2/7] net/tcp: Consistently align TCP-AO option in the header
To:     Dmitry Safonov <dima@arista.com>
Cc:     David Ahern <dsahern@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
        Jakub Kicinski <kuba@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        linux-kernel@vger.kernel.org,
        Dmitry Safonov <0x7f454c46@gmail.com>,
        Francesco Ruggeri <fruggeri05@gmail.com>,
        Salam Noureddine <noureddine@arista.com>,
        Simon Horman <horms@kernel.org>, netdev@vger.kernel.org
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On Wed, Nov 29, 2023 at 5:57=E2=80=AFPM Dmitry Safonov <dima@arista.com> wr=
ote:
>
> Currently functions that pre-calculate TCP header options length use
> unaligned TCP-AO header + MAC-length for skb reservation.
> And the functions that actually write TCP-AO options into skb do align
> the header. Nothing good can come out of this for ((maclen % 4) !=3D 0).
>
> Provide tcp_ao_len_aligned() helper and use it everywhere for TCP
> header options space calculations.
>
> Fixes: 1e03d32bea8e ("net/tcp: Add TCP-AO sign to outgoing packets")
> Signed-off-by: Dmitry Safonov <dima@arista.com>

Reviewed-by: Eric Dumazet <edumazet@google.com>