From owner-freebsd-net@FreeBSD.ORG  Fri Nov 29 02:54:07 2013
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 0FE347FC
 for <freebsd-net@freebsd.org>; Fri, 29 Nov 2013 02:54:07 +0000 (UTC)
Received: from mail-qe0-x22e.google.com (mail-qe0-x22e.google.com
 [IPv6:2607:f8b0:400d:c02::22e])
 (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits))
 (No client certificate requested)
 by mx1.freebsd.org (Postfix) with ESMTPS id C39C316B4
 for <freebsd-net@freebsd.org>; Fri, 29 Nov 2013 02:54:06 +0000 (UTC)
Received: by mail-qe0-f46.google.com with SMTP id a11so9956961qen.33
 for <freebsd-net@freebsd.org>; Thu, 28 Nov 2013 18:54:05 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113;
 h=mime-version:sender:in-reply-to:references:date:message-id:subject
 :from:to:cc:content-type;
 bh=l7bXGn4RWCL9aJDBclDTsVV5YTeEqUzatdpYX93lqVU=;
 b=IjKKIdDf+8u+15GcsQ1QqKgRgQii2T46wpp/50e7HMZmrIY6atOaidn5X1v0KlvN5B
 V/pd298Lg2hQJNceulS0ljPyPUvnMc8fK7GO987CCWrwJY8PIL1bgQCOWOloJKNW2W5U
 dyW5oGf3rZAD9jjrG1vTaIc17xrdWhFEroRhK2MhjCkqTD7Zj/Szl8ezE9O5Jw+XJTXw
 g1ilKLR8W+sjtBxi95RnjgHEvqzgK9+VcYqa6mYHvXMN/txP4mp+YRxSnV9WrTUZUK5o
 bEbUmWcuNsjEI34kXtPS5XpB0pNjyXNNlLegtgD6SDsyjffNNJurZSDDdsnuvRTQn0cl
 kSUw==
MIME-Version: 1.0
X-Received: by 10.224.64.196 with SMTP id f4mr46775344qai.55.1385693645882;
 Thu, 28 Nov 2013 18:54:05 -0800 (PST)
Sender: adrian.chadd@gmail.com
Received: by 10.224.53.200 with HTTP; Thu, 28 Nov 2013 18:54:05 -0800 (PST)
In-Reply-To: <BF7B04F7-0D45-4708-99A8-8BE030109CEC@lurchi.franken.de>
References: <BF7B04F7-0D45-4708-99A8-8BE030109CEC@lurchi.franken.de>
Date: Thu, 28 Nov 2013 18:54:05 -0800
X-Google-Sender-Auth: NMQInoVflg0HIHYQkEjTSakV1aM
Message-ID: <CAJ-Vmo=Jsf=7uXxwJ=Md5KLFpvSYAcaaNrq+bHsw75nfSG_ZaQ@mail.gmail.com>
Subject: Re: ip_output()/if_output() behaviour
From: Adrian Chadd <adrian@freebsd.org>
To: Michael Tuexen <Michael.Tuexen@lurchi.franken.de>
Content-Type: text/plain; charset=ISO-8859-1
Cc: "freebsd-net@freebsd.org list" <freebsd-net@freebsd.org>
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.16
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, 29 Nov 2013 02:54:07 -0000

On 28 November 2013 12:35, Michael Tuexen
<Michael.Tuexen@lurchi.franken.de> wrote:
> Dear all,
>
> I'm investigating a problem and need to understand the behaviour
> of ip_output(). Is it correct that if ip_output() returns an
> non-zero error, the corresponding packet was never sent?
> In the SCTP stack we assume this, but it seems that at least
> the em and the igb driver might return an error from
> igb_mq_start_locked(), for example, but have accepted the packet.

Which error(s) ?

> Before digging further, I would like to know what the intended
> behaviour of ip_output() is.


-adrian