Interesting TCP issue

[Steve Watt]

On Jan 22,  9:15, Uwe Doering wrote:
} Subject: Re: Interesting TCP issue
} Steve Watt wrote:
} > In <459AD141.5010502 at elischer.org>, Julian Elischer wrote:
} > 
} > [ Snip discussion of symptoms of window scaling broken when
} > talking to at least the skype mail servers. ]
} > 
} >> we have seen this since 4.x
} >> I think a fix may be in 7.0 but I'm not sure..
} >> I thin kthere is a problem when the far end sets the window down to 1 
} >> but scales it by a factor of 2^{big number}.
} >>
} >> Andre, can you check out this problem and MFC the correct fix
} >> if it is indeed the same problem in 6.2?
} > 
} > It is the same problem; I took the (one-line) fix as indicated by
} > 
} >> http://cvs.ironport.com/cgi-bin/viewcvs.cgi/freebsd/src/sys/netinet/tcp_syncache.c.diff?r1=1.84&r2=1.85
} > 
} > (well, not cvs.ironport.com, which doesn't seem to exist at the moment),
} > and applied the diff from 1.84 to
} > 1.85 and to a 6.2-PRERELEASE box updated around 25 Dec 06.
} > It works like a charm.
} > 
} > I would vote to MFC 1.85 now that 6.2 is out.
} 
} I wonder whether it is that easy.  As far as I can tell the commit to 
} HEAD actually comprised changes to three files:

I wonder as well, but that single diff fixes the problem I was running
into with the skype mail servers.

} http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_input.c.diff?r1=1.290&r2=1.291
} http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_syncache.c.diff?r1=1.84&r2=1.85
} http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_var.h.diff?r1=1.127&r2=1.128
} 
} How about the modifications in 'tcp_input.c'?  Are they relevant to the 
} problem this thread is about?  If so, assessing the correctness of an 
} MFC might prove to be a little harder.

Looking at it, yeah, those probably need to be picked up in some form as
well.  I didn't look closely at the tcpdump after, only observing that
it worked where it didn't before.

Hmm.

-- 
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