From owner-freebsd-bugs@FreeBSD.ORG  Fri Mar  5 10:55:46 2004
Return-Path: <owner-freebsd-bugs@FreeBSD.ORG>
Delivered-To: freebsd-bugs@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id 5C6ED16A4CE; Fri,  5 Mar 2004 10:55:46 -0800 (PST)
Received: from odin.ac.hmc.edu (Odin.AC.HMC.Edu [134.173.32.75])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id 3160C43D31; Fri,  5 Mar 2004 10:55:46 -0800 (PST)
	(envelope-from brdavis@odin.ac.hmc.edu)
Received: from odin.ac.hmc.edu (IDENT:brdavis@localhost.localdomain
	[127.0.0.1])
	by odin.ac.hmc.edu (8.12.10/8.12.3) with ESMTP id i25ItVRH020023;
	Fri, 5 Mar 2004 10:55:31 -0800
Received: (from brdavis@localhost)
	by odin.ac.hmc.edu (8.12.10/8.12.3/Submit) id i25ItU1d020021;
	Fri, 5 Mar 2004 10:55:30 -0800
Date: Fri, 5 Mar 2004 10:55:30 -0800
From: Brooks Davis <brooks@one-eyed-alien.net>
To: Stefan `Sec` Zehl <sec@42.org>
Message-ID: <20040305185527.GA16862@Odin.AC.HMC.Edu>
References: <20040304191443.67E9B1C8BA@ice.42.org>
	<200403041920.i24JK826047989@freefall.freebsd.org>
	<20040305181852.GC21713@ice.42.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20040305181852.GC21713@ice.42.org>
User-Agent: Mutt/1.5.4i
X-Virus-Scanned: by amavisd-milter (http://amavis.org/) on odin.ac.hmc.edu
cc: freebsd-bugs@freebsd.org
cc: FreeBSD-gnats-submit@freebsd.org
Subject: Re: kern/63772: tap device / exclusive open problem
X-BeenThere: freebsd-bugs@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Bug reports <freebsd-bugs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-bugs>
List-Post: <mailto:freebsd-bugs@freebsd.org>
List-Help: <mailto:freebsd-bugs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 05 Mar 2004 18:55:46 -0000

On Fri, Mar 05, 2004 at 07:18:52PM +0100, Stefan `Sec` Zehl wrote:
> On Thu, Mar 04, 2004 at 11:20 -0800, FreeBSD-gnats-submit@FreeBSD.org wrote:
> > Thank you very much for your problem report.
> > It has the internal identification `kern/63772'.
> 
> I have checked the if_tap.c in the current and stable branches, and was
> thus able to come up with an easy fix:
> 
> --- if_tap.c    Tue Feb 24 05:35:44 2004
> +++ if_tap.c.neu        Fri Mar  5 19:09:12 2004
> @@ -323,6 +323,9 @@
>         KASSERT(!(tp->tap_flags & TAP_OPEN), 
>                 ("%s flags is out of sync", tp->tap_if.if_xname));
>  
> +       if (tp->tap_flags & TAP_OPEN)
> +               return (EBUSY);
> +
>         bcopy(tp->arpcom.ac_enaddr, tp->ether_addr, sizeof(tp->ether_addr));
>  
>         tp->tap_pid = td->td_proc->p_pid;
> 
> 
> After this simple change, openvpn works with multiple tunnels again.

There's obviously something complicated going on since with INVARIANTS
enabled this would either return EBUSY or panic.  This should definitely
not be committed as is.

-- Brooks