From owner-freebsd-net@FreeBSD.ORG  Fri Aug 23 14:01:41 2013
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTP id 410CFF24
 for <freebsd-net@freebsd.org>; Fri, 23 Aug 2013 14:01:41 +0000 (UTC)
 (envelope-from andre@freebsd.org)
Received: from c00l3r.networx.ch (c00l3r.networx.ch [62.48.2.2])
 (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by mx1.freebsd.org (Postfix) with ESMTPS id A59CD29A1
 for <freebsd-net@freebsd.org>; Fri, 23 Aug 2013 14:01:40 +0000 (UTC)
Received: (qmail 86676 invoked from network); 23 Aug 2013 14:44:24 -0000
Received: from c00l3r.networx.ch (HELO [127.0.0.1]) ([62.48.2.2])
 (envelope-sender <andre@freebsd.org>)
 by c00l3r.networx.ch (qmail-ldap-1.03) with SMTP
 for <htandra@gloriad.org>; 23 Aug 2013 14:44:24 -0000
Message-ID: <52176B3A.1040804@freebsd.org>
Date: Fri, 23 Aug 2013 16:01:30 +0200
From: Andre Oppermann <andre@freebsd.org>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64;
 rv:17.0) Gecko/20130801 Thunderbird/17.0.8
MIME-Version: 1.0
To: Harika Tandra <htandra@gloriad.org>
Subject: Re: Netmap ixgbe stripping Vlan tags
References: <FC9BCAD9-5D16-4E70-A9C5-FA9D9A22B84C@gloriad.org>
 <521708E8.4000105@freebsd.org>
 <CACVs6=_Er_rmOcKz2UdT-98JPZktmE7q4smZUOhA9Fn-z+8yCw@mail.gmail.com>
 <5217494C.6060302@freebsd.org>
 <EDB2CF64-2241-486E-8B10-F8977EF88048@gloriad.org>
In-Reply-To: <EDB2CF64-2241-486E-8B10-F8977EF88048@gloriad.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: Juli Mallett <jmallett@FreeBSD.org>,
 "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.14
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: Fri, 23 Aug 2013 14:01:41 -0000

On 23.08.2013 15:12, Harika Tandra wrote:
> Hi all,
>
> I agree with Andre's statement
>> A netmap consumer
>> typically doesn't expect packets be mangled at all, mostly likely netmap is
>> expressly used to get the packet exactly as they were seen on the wire.
>
> For my application I want to see the whole packet as is (as seen on the wire).
> I am sure it is important for many users who are interested in
> using netmap for speedup of packet capture in network security/monitoring applications.
>
> When I disable "vlanhwfilter" flag on the interface. It is behaving as expected and is
> not stripping the Vlan tags when placed in promiscuous mode. Netmap seems to be ignoring
> his setting or is resetting this option  someplace (??). Any suggestion on where in Netmap
> code this maybe ?

When you switch an interface to netmap mode it does a soft-reset first.
That reverts the vlanhwfilter configuration to default on.  It's not
netmap that does it but the driver.  It seems to happen in or around
ixgbe_setup_vlan_hw_support().

-- 
Andre