From: "H.K. Jerry Chu" <hkjerry.chu@gmail.com>
To: David Miller <davem@davemloft.net>
Cc: eric.dumazet@gmail.com, alex@linlab.net, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] tcp: Wrong timeout for SYN segments
Date: Thu, 30 Aug 2012 11:04:21 -0700 [thread overview]
Message-ID: <CAFbMe2P-QhdkGGp=K6mdiW=g3CB_Z0C=Q8y=nz-nV6h2Q6WkcQ@mail.gmail.com> (raw)
In-Reply-To: <20120830.124543.1590020152319166487.davem@davemloft.net>
On Thu, Aug 30, 2012 at 9:45 AM, David Miller <davem@davemloft.net> wrote:
> From: Eric Dumazet <eric.dumazet@gmail.com>
> Date: Thu, 30 Aug 2012 06:12:30 -0700
>
>> On Wed, 2012-08-29 at 10:25 -0700, H.K. Jerry Chu wrote:
>>
>>> But it probably matter slightly more for TCP Fast Open (the server
>>> side patch has
>>> been completed and will be posted soon, after I finish breaking it up
>>> into smaller
>>> pieces for ease of review purpose), when a full socket will be created with data
>>> passed to the app upon a valid SYN+data. Dropping a fully functioning socket
>>> won't be the same as dropping a request_sock unknown to the app and letting
>>> the other side retransmitting SYN (w/o data this time).
>>>
>>> >
>>> > Sure, RFC numbers are what they are, but in practice, I doubt someone
>>> > will really miss the extra SYNACK sent after ~32 seconds, since it would
>>> > matter only for the last SYN attempted.
>>>
>>> I'd slightly prefer 1 extra retry plus longer wait time just to make
>>> TCP Fast Open
>>> a little more robust (even though the app protocol is required to be
>>> idempotent).
>>> But this is not a showstopper.
>>
>> Thats very good points indeed, thanks.
>>
>> Maybe we can increase SYNACK max retrans only if the FastOpen SYN cookie
>> was validated.
>>
>> This way, we increase reliability without amplifying the effect of wild
>> SYN packets.
>
> Can we come to a final conclusion on this last point and arrive at a final
> patch?
>
> Thanks.
Acked-by: H.K. Jerry Chu <hkchu@google.com>
next prev parent reply other threads:[~2012-08-30 18:04 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-21 23:29 [PATCH 1/1] tcp: Wrong timeout for SYN segments Alex Bergmann
2012-08-22 8:06 ` Eric Dumazet
2012-08-22 8:48 ` Alex Bergmann
2012-08-22 8:58 ` Eric Dumazet
2012-08-22 9:29 ` Alex Bergmann
2012-08-22 9:59 ` Eric Dumazet
2012-08-22 10:03 ` Eric Dumazet
2012-08-22 17:29 ` H.K. Jerry Chu
2012-08-22 16:44 ` H.K. Jerry Chu
[not found] ` <CAFbMe2M7ekc94bQk7vTS1LhScPd49VZ-zKOCUXhqwxXtL-nkuA@mail.gmail.com>
2012-08-23 11:58 ` Alex Bergmann
2012-08-23 12:15 ` Eric Dumazet
2012-08-23 12:35 ` David Laight
2012-08-23 12:51 ` Eric Dumazet
2012-08-23 12:37 ` Alex Bergmann
2012-08-23 12:49 ` Eric Dumazet
2012-08-24 12:17 ` Alex Bergmann
2012-08-24 17:42 ` David Miller
2012-08-25 8:48 ` Alexander Bergmann
2012-08-25 9:01 ` Eric Dumazet
2012-08-28 8:44 ` Carsten Wolff
[not found] ` <1346414260.2591.8.camel@edumazet-glaptop>
2012-08-31 12:48 ` Alexander Bergmann
2012-08-31 13:25 ` Eric Dumazet
2012-08-31 19:42 ` David Miller
2012-08-31 19:47 ` David Miller
2012-08-29 4:34 ` H.K. Jerry Chu
2012-08-29 8:51 ` Eric Dumazet
2012-08-29 17:25 ` H.K. Jerry Chu
2012-08-30 13:12 ` Eric Dumazet
2012-08-30 16:45 ` David Miller
2012-08-30 18:04 ` H.K. Jerry Chu [this message]
2012-08-30 17:59 ` H.K. Jerry Chu
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