From: David Miller <davem@davemloft.net>
To: netdev@vger.kernel.org
Cc: nhorman@tuxdriver.com, ilpo.jarvinen@helsinki.fi
Subject: BSD 4.2 style TCP keepalives
Date: Tue, 05 Jan 2010 16:39:11 -0800 (PST) [thread overview]
Message-ID: <20100105.163911.10233438.davem@davemloft.net> (raw)
To make a long story short, there are still some Windows 2000
machines out there emitting BSD 4.2 style keepalives (one garbage
byte instead of an empty out-of-window probe frame).
We don't ACK these because of how tcp_sequence() sees ->end_seq
as being equal to ->rcv_wup
But we can't change tcp_sequence() to reject these frames, because if
we do then we end up mishandling connection attempts (SYN, SYN+ACK)
and retransmits of such.
Neil has shown me a patch that does a by-hand special case of this
one-garbage-byte keepalive inside of tcp_rcv_established().
Anyone have suggestions for an alternative and perhaps cleaner
implementation of a fix?
Thanks!
next reply other threads:[~2010-01-06 0:39 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-06 0:39 David Miller [this message]
2010-01-06 2:07 ` BSD 4.2 style TCP keepalives 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
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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