From: David Miller <davem@davemloft.net>
To: ilpo.jarvinen@helsinki.fi
Cc: netdev@vger.kernel.org, nhorman@tuxdriver.com
Subject: Re: BSD 4.2 style TCP keepalives
Date: Wed, 06 Jan 2010 16:59:33 -0800 (PST) [thread overview]
Message-ID: <20100106.165933.226786062.davem@davemloft.net> (raw)
In-Reply-To: <alpine.DEB.2.00.1001070231540.26362@melkinpaasi.cs.helsinki.fi>
From: "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi>
Date: Thu, 7 Jan 2010 02:34:51 +0200 (EET)
> On Wed, 6 Jan 2010, David Miller wrote:
>
>> 3) tcp_data_queue() should make it to, and hit, this conditional:
>>
>> if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) {
>>
>> which will schedule an ACK the same exact way we would if
>> tcp_sequence() rejected the sequence range.
>>
>> So it's a mystery why we aren't responding to Windows 2000's
>> BSD 4.2 style zero window probes.
>>
>> Can someone please validate my analysis?
>
> In 3) I don't see why we'd hit that one as peer's snd_una+1 would be
> larger than rcv_nxt.
Peer constructs keepalive packet using sequence [snd.una-1,snd.una],
both of which are <= rcv_nxt
next prev parent reply other threads:[~2010-01-07 0:59 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-06 0:39 BSD 4.2 style TCP keepalives David Miller
2010-01-06 2:07 ` Neil Horman
2010-01-06 3:59 ` David Miller
2010-01-06 17:21 ` Rick Jones
2010-01-06 20:50 ` Neil Horman
2010-01-06 8:23 ` David Miller
2010-01-06 23:04 ` David Miller
2010-01-07 0:14 ` David Miller
2010-01-07 3:21 ` David Miller
2010-01-07 3:36 ` David Miller
2010-01-07 0:34 ` Ilpo Järvinen
2010-01-07 0:59 ` David Miller [this message]
2010-01-07 7:55 ` Ilpo Järvinen
2010-01-08 12:40 ` Neil Horman
2010-01-08 21:21 ` David Miller
2010-01-09 1:22 ` Neil Horman
2010-01-09 1:41 ` David Miller
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