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From:   Eric Dumazet <edumazet@google.com>
Date:   Wed, 11 Oct 2023 20:10:19 +0200
Message-ID: <CANn89iLD=ySFfPYkrb+oN2fuMhimxXfHrhs4Pv9_60f912rzmQ@mail.gmail.com>
Subject: Re: [PATCH v14 net-next 09/23] net/tcp: Add TCP-AO sign to twsk
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,
        Andy Lutomirski <luto@amacapital.net>,
        Ard Biesheuvel <ardb@kernel.org>,
        Bob Gilligan <gilligan@arista.com>,
        Dan Carpenter <error27@gmail.com>,
        David Laight <David.Laight@aculab.com>,
        Dmitry Safonov <0x7f454c46@gmail.com>,
        Donald Cassidy <dcassidy@redhat.com>,
        Eric Biggers <ebiggers@kernel.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Francesco Ruggeri <fruggeri05@gmail.com>,
        "Gaillardetz, Dominik" <dgaillar@ciena.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        Ivan Delalande <colona@arista.com>,
        Leonard Crestez <cdleonard@gmail.com>,
        "Nassiri, Mohammad" <mnassiri@ciena.com>,
        Salam Noureddine <noureddine@arista.com>,
        Simon Horman <simon.horman@corigine.com>,
        "Tetreault, Francois" <ftetreau@ciena.com>, netdev@vger.kernel.org
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On Tue, Oct 10, 2023 at 1:07=E2=80=AFAM Dmitry Safonov <dima@arista.com> wr=
ote:
>
> Add support for sockets in time-wait state.
> ao_info as well as all keys are inherited on transition to time-wait
> socket. The lifetime of ao_info is now protected by ref counter, so
> that tcp_ao_destroy_sock() will destruct it only when the last user is
> gone.
>
> Co-developed-by: Francesco Ruggeri <fruggeri@arista.com>
> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
> Co-developed-by: Salam Noureddine <noureddine@arista.com>
> Signed-off-by: Salam Noureddine <noureddine@arista.com>
> Signed-off-by: Dmitry Safonov <dima@arista.com>
> Acked-by: David Ahern <dsahern@kernel.org>
> ---
>  include/linux/tcp.h      |  3 ++
>  include/net/tcp_ao.h     | 11 ++++-
>  net/ipv4/tcp_ao.c        | 46 +++++++++++++++++---
>  net/ipv4/tcp_ipv4.c      | 92 +++++++++++++++++++++++++++++++---------
>  net/ipv4/tcp_minisocks.c |  4 +-
>  net/ipv4/tcp_output.c    |  2 +-
>  net/ipv6/tcp_ipv6.c      | 72 ++++++++++++++++++++++---------
>  7 files changed, 181 insertions(+), 49 deletions(-)
>
> diff --git a/include/linux/tcp.h b/include/linux/tcp.h
> index c38778b0baa0..51458219be4e 100644
> --- a/include/linux/tcp.h
> +++ b/include/linux/tcp.h
> @@ -512,6 +512,9 @@ struct tcp_timewait_sock {
>  #ifdef CONFIG_TCP_MD5SIG
>         struct tcp_md5sig_key     *tw_md5_key;
>  #endif
> +#ifdef CONFIG_TCP_AO
> +       struct tcp_ao_info      __rcu *ao_info;
> +#endif
>  };
>
>  static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)
> diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
> index 629ab0365b83..af2caf7e76fc 100644
> --- a/include/net/tcp_ao.h
> +++ b/include/net/tcp_ao.h
> @@ -85,6 +85,7 @@ struct tcp_ao_info {
>                                 __unused        :31;
>         __be32                  lisn;
>         __be32                  risn;
> +       atomic_t                refcnt;         /* Protects twsk destruct=
ion */

This needs to be a refcount_t