From owner-freebsd-net@FreeBSD.ORG  Thu Dec 13 11:46:29 2012
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
 by hub.freebsd.org (Postfix) with ESMTP id F3E02B97
 for <freebsd-net@FreeBSD.org>; Thu, 13 Dec 2012 11:46:28 +0000 (UTC)
 (envelope-from avg@FreeBSD.org)
Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140])
 by mx1.freebsd.org (Postfix) with ESMTP id 4D5AD8FC08
 for <freebsd-net@FreeBSD.org>; Thu, 13 Dec 2012 11:46:27 +0000 (UTC)
Received: from odyssey.starpoint.kiev.ua (alpha-e.starpoint.kiev.ua
 [212.40.38.101])
 by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id NAA14855
 for <freebsd-net@freebsd.org>; Thu, 13 Dec 2012 13:46:26 +0200 (EET)
 (envelope-from avg@FreeBSD.org)
Message-ID: <50C9C012.8020306@FreeBSD.org>
Date: Thu, 13 Dec 2012 13:46:26 +0200
From: Andriy Gapon <avg@FreeBSD.org>
User-Agent: Mozilla/5.0 (X11; FreeBSD amd64;
 rv:17.0) Gecko/17.0 Thunderbird/17.0
MIME-Version: 1.0
To: freebsd-net@FreeBSD.org
Subject: ng_ether naming
X-Enigmail-Version: 1.4.6
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
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: Thu, 13 Dec 2012 11:46:29 -0000


ng_ether uses if_xname for naming its nodes.
This could be troublesome for mapping interface names to their ng_ether companions
in the face of interface renaming capability.  Especially given that interface
renaming and ng_ether _module_ loading may happen in an arbitrary order.

I am not sure how to solve this best.

One possibility is to use if_dname+if_dunit combination for ng_ether naming.  This
should be stable and available for querying.  This behavior should also be
backward compatible with ng_ether being compiled into kernel (if_dname+if_dunit ==
if_xname before any renaming could occur).

Another possibility is to do ng_ether renaming when its interface is renamed.
This seems nicer but appears to be more work and more intrusive, because
interfaces would have to know about their ng_ether nodes.

What do you think?
Thank you.

And just in case:
$ ifconfig -l
net0 lo0
$ ngctl list
There are 2 total nodes:
  Name: re0             Type: ether           ID: 00000001   Num hooks: 0
  Name: ngctl11353      Type: socket          ID: 00000003   Num hooks: 0

-- 
Andriy Gapon