From owner-freebsd-net@FreeBSD.ORG  Thu Sep 25 19:44:20 2014
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id 8DB07E58;
 Thu, 25 Sep 2014 19:44:20 +0000 (UTC)
Received: from cell.glebius.int.ru (glebius.int.ru [81.19.69.10])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client CN "cell.glebius.int.ru", Issuer "cell.glebius.int.ru" (not verified))
 by mx1.freebsd.org (Postfix) with ESMTPS id 0D51768E;
 Thu, 25 Sep 2014 19:44:19 +0000 (UTC)
Received: from cell.glebius.int.ru (localhost [127.0.0.1])
 by cell.glebius.int.ru (8.14.9/8.14.9) with ESMTP id s8PJiFpq042734
 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO);
 Thu, 25 Sep 2014 23:44:15 +0400 (MSK)
 (envelope-from glebius@FreeBSD.org)
Received: (from glebius@localhost)
 by cell.glebius.int.ru (8.14.9/8.14.9/Submit) id s8PJiFZD042733;
 Thu, 25 Sep 2014 23:44:15 +0400 (MSK)
 (envelope-from glebius@FreeBSD.org)
X-Authentication-Warning: cell.glebius.int.ru: glebius set sender to
 glebius@FreeBSD.org using -f
Date: Thu, 25 Sep 2014 23:44:15 +0400
From: Gleb Smirnoff <glebius@FreeBSD.org>
To: "Andrey V. Elsukov" <ae@FreeBSD.org>
Subject: Re: svn commit: r272089 - head/sys/netpfil/ipfw
Message-ID: <20140925194415.GD884@glebius.int.ru>
References: <201409250226.s8P2Q6AS055635@svn.freebsd.org>
 <CAJ-VmomsRHxiUtDw8FpP=ZGcE136dBLpDyzcpnRVbVFyk0Jmnw@mail.gmail.com>
 <20140925051808.GS884@FreeBSD.org> <1411643223.2161.2.camel@bruno>
 <54241F1D.4080206@FreeBSD.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <54241F1D.4080206@FreeBSD.org>
User-Agent: Mutt/1.5.23 (2014-03-12)
Cc: FreeBSD Net <freebsd-net@freebsd.org>,
 David Carlier <david.carlier@hardenedbsd.org>,
 Adrian Chadd <adrian@freebsd.org>
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.18-1
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/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: Thu, 25 Sep 2014 19:44:20 -0000

On Thu, Sep 25, 2014 at 05:56:45PM +0400, Andrey V. Elsukov wrote:
A> > Ok, moving off to freebsd-net.  How should we proceded with debugging
A> > further?
A> 
A> Probably this can occurs when outgoing interface disappeared
A> (netgrapg/tun/tap/lagg/vlan/usb ethernet), but packets were not send yet
A> (delayed in the dummynet pipe). I think this is well known problem.

AFAIK, when an mbuf leaves an interface, it completely detaches
from it. There is no mechanism to clear all rcvif pointers on all
mbufs travelling through stack when interface departs. Yes, here
I describe another problem: interface departs, and rcvif pointers
are stale. This is known and old problem. But the pointers are
not NULL.

-- 
Totus tuus, Glebius.