From owner-freebsd-net@FreeBSD.ORG Sun Jan 6 17:50:05 2008 Return-Path: Delivered-To: freebsd-net@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9538D16A417 for ; Sun, 6 Jan 2008 17:50:05 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 92EFF13C45B for ; Sun, 6 Jan 2008 17:50:05 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.2/8.14.2) with ESMTP id m06Ho5nb010168 for ; Sun, 6 Jan 2008 17:50:05 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.2/8.14.1/Submit) id m06Ho5bX010167; Sun, 6 Jan 2008 17:50:05 GMT (envelope-from gnats) Date: Sun, 6 Jan 2008 17:50:05 GMT Message-Id: <200801061750.m06Ho5bX010167@freefall.freebsd.org> To: freebsd-net@FreeBSD.org From: Bob Van Zant Cc: Subject: Re: kern/116837: ifconfig tunX destroy: panic X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Bob Van Zant List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 06 Jan 2008 17:50:05 -0000 The following reply was made to PR kern/116837; it has been noted by GNATS. From: Bob Van Zant To: bug-followup@FreeBSD.org Cc: Subject: Re: kern/116837: ifconfig tunX destroy: panic Date: Sun, 6 Jan 2008 22:46:09 +0530 My FreeBSD 7.0-PRERELEASE box has been running into this problem a lot recently when I reset my ppp connection to counteract the effects of having a very poor ISP. I would like to fix this bug. Is there anyone that can help me identify what the proper behavior is? In my case the repro is something along the lines of: - Create ppp connection (tun0) - Create six-to-four connection (stf0) - The ppp connection gets wedged - /etc/rc.d/ppp stop - ifconfig tun0 destroy - kernel panic My hunch is that the stf0 interface being "on top" of tun0 is causing the problem. I've changed the script, maybe the panic will stop happening. But what should the behavior be? Should the if_tun code make an attempt to clean up whatever it can and then just destroy the interface like requested? Or should it return some sort of error and the ifconfig request to destroy the interface fails? The if_tap code appears to have the same assert in its destroy function and we may want to fix that as well. I tend to get a few spare hours during any given week to play with these sorts of things and I'd like to be able to help out with this one. Any sort of direction folks can give in working towards a solution will be appreciated. -Bob