From: Andi Kleen <andi@firstfloor•org>
To: Oliver Zheng <mailinglists+netdev@oliverzheng•com>
Cc: netdev@vger•kernel.org
Subject: Re: TCP/IP stack interpretation of acceptable packet
Date: Sat, 28 Feb 2009 16:50:46 +0100 [thread overview]
Message-ID: <87iqmu36i1.fsf@basil.nowhere.org> (raw)
In-Reply-To: <2ff60cd60902241459q1de39054lb3dc5233f13b69c3@mail.gmail.com> (Oliver Zheng's message of "Tue, 24 Feb 2009 14:59:55 -0800")
Oliver Zheng <mailinglists+netdev@oliverzheng•com> writes:
> I was investigating behaviour of the TCP/IP stacks and noticed that
> Linux has a peculiarity. When a packet is received with the correct
> sequence number but incorrect acknowledgement number (in my tests, it
> was higher than the correct acknowledgement number), the stack accepts
> the packet as a valid packet and passes the data up to the application
> (I do not know whether the ack information is accepted). According to
> the list of tests described here in the TCP RFC 793 [1], accepting a
> packet requires the packet to satisfy both sequence and
> acknowledgement number tests; otherwise, the entirety of the packet
> (its data and its acknowledgement information confirming reception of
> previous data) should be dropped. Is this intentional, a bug, or am I
> misinterpreting something? A nice flow chart that explains this
> procedure is here [2].
Sounds like a bug to me, when the ack is outside the window.
-Andi
--
ak@linux•intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2009-02-28 15:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-24 22:59 TCP/IP stack interpretation of acceptable packet Oliver Zheng
2009-02-28 15:50 ` Andi Kleen [this message]
2009-03-19 0:44 ` [PATCH net-next-2.6] " John Dykstra
2009-03-19 1:47 ` Oliver Zheng
2009-03-23 4:50 ` David Miller
2009-03-23 12:28 ` Andi Kleen
2009-03-23 15:13 ` John Dykstra
2009-03-23 18:58 ` David Miller
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