netdev - Re: [PATCH net-next v3 3/6] tcp: add dropreasons in tcp_rcv_state

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Message-ID: <CANn89iKmG=PbXpCfOotWJ3_890Zm-PKYKA5nB2dFhdvdd6YfEQ@mail.gmail.com>
Date: Mon, 12 Feb 2024 16:32:55 +0100
From: Eric Dumazet <edumazet@...gle.com>
To: Jason Xing <kerneljasonxing@...il.com>
Cc: davem@...emloft.net, kuba@...nel.org, pabeni@...hat.com, 
	dsahern@...nel.org, netdev@...r.kernel.org, 
	Jason Xing <kernelxing@...cent.com>
Subject: Re: [PATCH net-next v3 3/6] tcp: add dropreasons in tcp_rcv_state_process()

On Mon, Feb 12, 2024 at 10:29 AM Jason Xing <kerneljasonxing@...il.com> wrote:
>
> From: Jason Xing <kernelxing@...cent.com>


>                         if (!acceptable)
> -                               return 1;
> +                               /* This reason isn't clear. We can refine it in the future */
> +                               return SKB_DROP_REASON_TCP_CONNREQNOTACCEPTABLE;

tcp_conn_request() might return 0 when a syncookie has been generated.

Technically speaking, the incoming SYN was not dropped :)

I think you need to have a patch to change tcp_conn_request() and its
friends to return a 'refined' drop_reason
to avoid future questions / patches.