netdev - Re: [PATCH net-next] tcp: accept RST for rcv_nxt

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Message-ID: <6bbb94ef-9be6-6238-270b-fec5304a65c7@hpe.com>
Date:   Tue, 17 Jan 2017 11:19:58 -0800
From:   Rick Jones <rick.jones2@....com>
To:     Eric Dumazet <edumazet@...gle.com>
Cc:     Jason Baron <jbaron@...mai.com>,
        David Miller <davem@...emloft.net>,
        netdev <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next] tcp: accept RST for rcv_nxt - 1 after receiving
 a FIN

On 01/17/2017 11:13 AM, Eric Dumazet wrote:
> On Tue, Jan 17, 2017 at 11:04 AM, Rick Jones <rick.jones2@....com> wrote:
>> Drifting a bit, and it doesn't change the value of dealing with it, but out
>> of curiosity, when you say mostly in CLOSE_WAIT, why aren't the server-side
>> applications reacting to the read return of zero triggered by the arrival of
>> the FIN?
>
> Even if the application reacts, and calls close(fd), kernel will still
> try to push the data that was queued into socket write queue prior to
> receiving the FIN.
>
> By allowing this RST, we can flush the whole data and react much
> faster, avoiding locking memory in the kernel for very long time.

Understood.  I was just wondering if there is also an application bug here.

happy benchmarking,

rick jones