From owner-freebsd-net@FreeBSD.ORG Thu Feb 15 21:47:26 2007 Return-Path: X-Original-To: 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 7198C16A408 for ; Thu, 15 Feb 2007 21:47:26 +0000 (UTC) (envelope-from jdp@polstra.com) Received: from rock.polstra.com (rock.polstra.com [64.119.0.113]) by mx1.freebsd.org (Postfix) with ESMTP id 531BB13C4BD for ; Thu, 15 Feb 2007 21:47:26 +0000 (UTC) (envelope-from jdp@polstra.com) Received: from strings.polstra.com (strings.polstra.com [64.81.189.67]) (authenticated bits=0) by rock.polstra.com (8.13.8/8.13.8) with ESMTP id l1FLlONp003668; Thu, 15 Feb 2007 13:47:25 -0800 (PST) (envelope-from jdp@polstra.com) Message-ID: X-Mailer: XFMail 1.5.5 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: Date: Thu, 15 Feb 2007 13:47:24 -0800 (PST) From: John Polstra To: Kip Macy X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-3.0 (rock.polstra.com [64.119.0.113]); Thu, 15 Feb 2007 13:47:25 -0800 (PST) Cc: freebsd-net@freebsd.org Subject: Re: bge0: discard frame w/o packet header 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: Thu, 15 Feb 2007 21:47:26 -0000 On 15-Feb-2007 Kip Macy wrote: >> >> The "discard frame w/o packet header" message comes from ether_input() >> if it gets an mbuf that doesn't have the M_PKTHDR flag set. That >> can't happen unless something is very wrong with the system. I'd like >> to make it a panic. At least then the machine would reboot instead of >> just becoming unreachable. Any objections? > > Please don't make it the default. Odds are ifconfig down, ifconfig up > would fix it for those of us with console access. That may be the case, but you might not notice it for many hours. I'd think most folks would want the system to recover on its own, by rebooting. > Either way it sounds like someone has discovered a DOS in bge. No, it just about has to be a bug -- either in the mbuf allocator, the driver, or the NIC hardware. M_PKTHDR is a flag in the mbuf header, an area that isn't touched by packet data. The driver allocates all of its receive mbufs with the M_PKTHDR flag set. There's no legitimate way for the flag to get cleared, and nothing coming in on the wire should be able to cause it to be cleared. John