From owner-freebsd-hackers@FreeBSD.ORG  Sun Jul 21 04:13:40 2013
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by hub.freebsd.org (Postfix) with ESMTP id 2F503E7D
 for <freebsd-hackers@freebsd.org>; Sun, 21 Jul 2013 04:13:40 +0000 (UTC)
 (envelope-from n7w@delta.emu.st)
Received: from smtp1.bushwire.net (f5.bushwire.net [199.48.133.46])
 by mx1.freebsd.org (Postfix) with SMTP id D613E162
 for <freebsd-hackers@freebsd.org>; Sun, 21 Jul 2013 04:13:38 +0000 (UTC)
Received: (qmail 2129 invoked by uid 1001); 21 Jul 2013 04:13:38 -0000
Delivered-To: qmda-intercept-freebsd-hackers@freebsd.org
DomainKey-Signature: a=rsa-sha1; q=dns; c=simple; s=s384; d=delta.emu.st; 
 b=k2VMzWegp4iV+q4/Al7OWqMdPrgIQLeda7PozB2rUrrUIP5L9DMIbkODQjNNajnq;
Comments: DomainKeys? See http://en.wikipedia.org/wiki/DomainKeys
DomainKey-Trace-MD: h=13; b=20; l=C18R70D32M64F38T31S69R80?45M17C39C27I57;
Comments: QMDA 0.3
Received: (qmail 2122 invoked by uid 1001); 21 Jul 2013 04:13:38 -0000
Date: 21 Jul 2013 04:13:38 +0000
Message-ID: <20130721041338.2121.qmail@f5-external.bushwire.net>
From: "Mark Delany" <n7w@delta.emu.st>
To: freebsd-hackers@freebsd.org
Subject: Re: bin/176713: [patch] nc(1) closes network socket too soon
References: <CAGwOe2ZEV3o-=Z1A3PgBtChAEhMbqB5fwPx-7emGbTSJ7AyMPA@mail.gmail.com>
 <24574.1374375946@server1.tristatelogic.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <24574.1374375946@server1.tristatelogic.com>
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
 <freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
 <mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 21 Jul 2013 04:13:40 -0000

> servers running certain protocols.  For example, the rules of the SMTP
> protocol... just to name one... require that a client wait until the
> server has sent out an initial greeting banner before the client sends
> anything to the server.  Some SMTP servers are lenient about enforcing
> this protocol rule, so in practice it may often not be necessary to wait

A while back "fast talkers" as they were called, were a known
signature of some spam bots. The guess is that they would just write
the whole SMTP transaction in one write() immediately following the
connect() and be done with it. A useful optimization when you're
blatting out billions of spam.

You don't see a big mention of this in search engines, so I don't know
how prevalent they are now.

Point being that such an option might be useful to avoid triggering
any detectors that might still be looking for this.


Mark.