From owner-freebsd-net@FreeBSD.ORG  Fri Jun 19 21:43:27 2009
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 838671065676;
	Fri, 19 Jun 2009 21:43:27 +0000 (UTC)
	(envelope-from wollman@hergotha.csail.mit.edu)
Received: from hergotha.csail.mit.edu (hergotha.csail.mit.edu [66.92.79.170])
	by mx1.freebsd.org (Postfix) with ESMTP id 384D68FC15;
	Fri, 19 Jun 2009 21:43:26 +0000 (UTC)
	(envelope-from wollman@hergotha.csail.mit.edu)
Received: from hergotha.csail.mit.edu (localhost [127.0.0.1])
	by hergotha.csail.mit.edu (8.14.2/8.14.2) with ESMTP id n5JLRTbY042618; 
	Fri, 19 Jun 2009 17:27:29 -0400 (EDT)
	(envelope-from wollman@hergotha.csail.mit.edu)
Received: (from wollman@localhost)
	by hergotha.csail.mit.edu (8.14.2/8.13.8/Submit) id n5JLRTtE042617;
	Fri, 19 Jun 2009 17:27:29 -0400 (EDT) (envelope-from wollman)
Date: Fri, 19 Jun 2009 17:27:29 -0400 (EDT)
From: Garrett Wollman <wollman@hergotha.csail.mit.edu>
Message-Id: <200906192127.n5JLRTtE042617@hergotha.csail.mit.edu>
To: andre@freebsd.org
X-Newsgroups: mit.lcs.mail.freebsd-net
In-Reply-To: <4A3BF2DF.6080603@freebsd.org>
References: <20090619191756.R581@beagle.kn.op.dlr.de>
Organization: None
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0
	(hergotha.csail.mit.edu [127.0.0.1]);
	Fri, 19 Jun 2009 17:27:29 -0400 (EDT)
X-Spam-Status: No, score=-1.4 required=5.0 tests=ALL_TRUSTED
	autolearn=disabled version=3.2.5
X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on
	hergotha.csail.mit.edu
Cc: net@freebsd.org
Subject: Re: TCP bug?
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 19 Jun 2009 21:43:27 -0000

In article <4A3BF2DF.6080603@freebsd.org>, Andre writes:

>2) in old T/TCP (RFC1644) which we supported in our TCP code the SYN/FIN
>    combination was a valid one, though not directly intended for SYN/ACK/FIN.

It still is valid, and should be possible to generate using sendmsg()
and MSG_EOF.  Nothing about this depends on T/TCP, which is solely
about reducing the three-way handshake to a two-way handshake.

-GAWollman