From owner-freebsd-net@FreeBSD.ORG  Tue Aug 28 02:15:29 2007
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 00FE916A418
	for <freebsd-net@freebsd.org>; Tue, 28 Aug 2007 02:15:29 +0000 (UTC)
	(envelope-from Susan.Lan@zyxel.com.tw)
Received: from zyfb01-66.zyxel.com.tw (zyfb01-66.zyxel.com.tw [59.124.183.66])
	by mx1.freebsd.org (Postfix) with ESMTP id 9F61913C46B
	for <freebsd-net@freebsd.org>; Tue, 28 Aug 2007 02:15:28 +0000 (UTC)
	(envelope-from Susan.Lan@zyxel.com.tw)
Received: from zytwbe01.zyxel.com ([172.23.5.10]) by zyfb01-66.zyxel.com.tw
	with Microsoft SMTPSVC(6.0.3790.1830); 
	Tue, 28 Aug 2007 10:15:27 +0800
Received: from zytwfe01.ZyXEL.com ([172.23.5.5]) by zytwbe01.zyxel.com with
	Microsoft SMTPSVC(6.0.3790.1830); Tue, 28 Aug 2007 10:15:26 +0800
Received: from [172.23.17.9] ([172.23.17.9]) by zytwfe01.ZyXEL.com with
	Microsoft SMTPSVC(6.0.3790.1830); Tue, 28 Aug 2007 10:15:26 +0800
Message-ID: <46D38543.4020507@zyxel.com.tw>
Date: Tue, 28 Aug 2007 10:15:31 +0800
From: blue <susan.lan@zyxel.com.tw>
User-Agent: Mozilla Thunderbird 0.9 (Windows/20041103)
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: freebsd-net@freebsd.org
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-OriginalArrivalTime: 28 Aug 2007 02:15:26.0600 (UTC)
	FILETIME=[4C3F0080:01C7E919]
Subject: infinite loop in esp6_ctlinput()?
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: Tue, 28 Aug 2007 02:15:29 -0000

Dear all:

When receiving a "packet too big" ICMP error message, FreeBSD will call 
the ctlinput() function of the upper protocol. If the preceding packet 
is an ESP  IPv6 packet, then FreeBSD will call esp6_ctlinput(). In 
esp6_ctlinput(), pfctlinput2() will be executed to traverse all possible 
upper protocols, and call their registered ctlinput() function. However, 
that would call esp6_ctlinput() again since ESP is one of the upper 
protocols! Then an infinite loop occurs!!

After comparing both IPSEC and FAST_IPSEC, the operations are exactly 
the same. Is it a bug?

Best regards,

Yi-Wen