From owner-freebsd-bugs@FreeBSD.ORG  Wed Dec 16 16:38:11 2009
Return-Path: <owner-freebsd-bugs@FreeBSD.ORG>
Delivered-To: freebsd-bugs@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 0FE3C1065670
	for <freebsd-bugs@freebsd.org>; Wed, 16 Dec 2009 16:38:11 +0000 (UTC)
	(envelope-from fengdreamer@126.com)
Received: from m15-75.126.com (m15-75.126.com [220.181.15.75])
	by mx1.freebsd.org (Postfix) with SMTP id 0FA108FC17
	for <freebsd-bugs@freebsd.org>; Wed, 16 Dec 2009 16:38:09 +0000 (UTC)
Received: from fengdreamer (  [219.237.185.38] ) by ajax-webmail-wmsvr75
	(Coremail) ; Thu, 17 Dec 2009 00:07:23 +0800 (CST)
Date: Thu, 17 Dec 2009 00:07:23 +0800 (CST)
From: =?gbk?B?zfW0urfn?= <fengdreamer@126.com>
To: freebsd-bugs <freebsd-bugs@freebsd.org>
Message-ID: <7633578.1174971260979643891.JavaMail.coremail@bj126app75.126.com>
MIME-Version: 1.0
X-Originating-IP: [219.237.185.38]
X-Priority: 3
X-Mailer: Coremail Webmail Server Version SP_ntes V3.5 build
	090923(9022.2651.2651) Copyright (c) 2002-2009 www.mailtech.cn 126com
X-CM-CTRLDATA: prFDBGZvb3Rlcl9odG09MTI3OTo0NA==
X-CM-TRANSID: S8qowLA79CW8BSlLwA4WAg--.23563W
X-CM-SenderInfo: pihqwv5uhdzvbu6rjloofrz/1tbi3gg7s0kZi+n+mgAAsI
X-Coremail-Antispam: 1Ur529EdanIXcx71UUUUU7IcSsGvfJTRUUUbbkYjxAI6xAIw2
	8IcVW8XFylb7IF0VCF04k20xvEw2I207IF0wAYjxAI6xCIbckI1I0E57IF64kEYxAxMc80
	4VCqF7xvr2I5M4IEnf9ElVAFpTB2q-sK649IAas0WaI_GwCS07vEb7Iv0xC_Jr1lV2xY67
	kC6x804xWlV2xY67AvxsIEb2xv6ckvw2WlV2xY67CY07I20VC2zVCF04k26cxKx2IYs7xG
	6rWj6s0DMIAIbVAFxVCF77xC64kEw24lV2xY67C26IkvcIIF6IxKo4kEV4ylV2xY628EF7
	xvwVC0I7IYx2IY67AKxVWDJVCq3wCS07vE84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_GcCE
	3s1lV2xY628EF7xvwVC2z280aVAFwI0_GcCE3s1lV2xY628EF7xvwVC2z280aVCY1x0267
	AKxVW0oVCq3wCS07vE5I8CrVACY4xI64kE6c02F40Ex7xfMIAIbVAv7VC0I7IYx2IY67AK
	xVWUGVWUXwCS07vEYx0Ex4A2jsIE14v26r1j6r4UMIAIbVCjxxvEw4WlV2xY6xkIecxEwV
	AFwVWUMIAIbVCY0x0Ix7I2Y4AK64vIr41lV2xY6xCjnVCjjxCrMIAIbVC2zVAF1VAY17CE
	14v26r1j6r15MIAIbVCI42IY6xAIw20EY4v20xvaj40_Wr1j6rW3JrUvcSsGvfC2KfnxnU
	U==
X-Mailman-Approved-At: Wed, 16 Dec 2009 16:46:58 +0000
Content-Type: text/plain; charset=gbk
Content-Transfer-Encoding: 7bit
X-Content-Filtered-By: Mailman/MimeDel 2.1.5
Subject: Bug discussion:Tcp snd_nxt will not be increased.
X-BeenThere: freebsd-bugs@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Bug reports <freebsd-bugs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-bugs>
List-Post: <mailto:freebsd-bugs@freebsd.org>
List-Help: <mailto:freebsd-bugs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 16 Dec 2009 16:38:11 -0000

Hello All:
 
There's a problem i am facing. Is it a bug ?
It's tcp connect socket, SYN will be send, but if before SYN ACK was received, the SYN will be retransmited, there'll be some problem.
the restransmit is like this: move the snd_nxt to snd_una, and begin to sendout by tcp_output. after send the snd_nxt will return to normal just like the below picture. 
 before tcp_output               after tcp output
 |--Seq--|--Seq+1--|             |--Seq--|--Seq+1--|
  snd_una                         snd_una  snd_nxt
  snd_nxt               
If the tcp_output just have some error, for example: when alloc mbuf, it returns NULL, and then the snd_nxt number will not be return to normal.
If just in this time, SYN Ack arrives, freeBSD can't handle this situdition.
 
Thanks!