From owner-freebsd-net@FreeBSD.ORG Wed Nov 8 14:34:42 2006 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 35D2816A407 for ; Wed, 8 Nov 2006 14:34:42 +0000 (UTC) (envelope-from bms@FreeBSD.org) Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com [66.111.4.25]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8AB9543E01 for ; Wed, 8 Nov 2006 14:33:10 +0000 (GMT) (envelope-from bms@FreeBSD.org) Received: from db2.internal (db2.internal [10.202.2.12]) by frontend1.messagingengine.com (Postfix) with ESMTP id E5DAADC13ED; Wed, 8 Nov 2006 09:33:01 -0500 (EST) Received: from heartbeat2.messagingengine.com ([10.202.2.161]) by db2.internal (MEProxy); Wed, 08 Nov 2006 09:33:03 -0500 X-Sasl-enc: tQYMA8AwW5IGw5PjGu4a/qXBd+nNab1T82vmCIifBBKe 1162996383 Received: from [192.168.123.18] (82-35-112-254.cable.ubr07.dals.blueyonder.co.uk [82.35.112.254]) by mail.messagingengine.com (Postfix) with ESMTP id B663910C96; Wed, 8 Nov 2006 09:33:02 -0500 (EST) Message-ID: <4551EA9C.5050309@FreeBSD.org> Date: Wed, 08 Nov 2006 14:33:00 +0000 From: "Bruce M. Simpson" User-Agent: Thunderbird 1.5.0.5 (X11/20060825) MIME-Version: 1.0 To: Landon Fuller References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: Re: [patch] tun(4) and tap(4) if_clone support. X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 08 Nov 2006 14:34:42 -0000 Landon Fuller wrote: > Nick Barkas (snb@threerings.net) and I have added interface cloning > support to the tun(4) and tap(4) drivers. > > We maintained backwards-compatible support for devfs cloning, which is > now disabled by default -- it can be re-enabled via a sysctl. > Interfaces that are created via devfs cloning may still be removed via > ifconfig destroy. > > The latest patch is available here > http://www.opendarwin.org/~landonf/code/patch-tuntap_ifclone > > I've submitted kern/105228 with the patch, and I'd be most > appreciative of comments/suggestions. Interesting stuff. If it eliminates a race on creation, that has to be a good thing; I may have run into this race in the past month or two. It would however change tap/tun behaviour in that currently I have a few scripts which use dd(1) to force the device node to be created. This is undocumented behaviour specific to its devfs implementation which perhaps I shouldn't be relying upon, before I go on to create a bridge from several tap instances (which are then hooked up to QEMU virtual machines). Good work! BMS