Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 7 Aug 2002 07:13:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 7 Aug 2002 07:13:23 -0400 Received: from chaos.analogic.com ([204.178.40.224]:43909 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id ; Wed, 7 Aug 2002 07:13:22 -0400 Date: Wed, 7 Aug 2002 07:18:17 -0400 (EDT) From: "Richard B. Johnson" Reply-To: root@chaos.analogic.com To: Dax Kelson cc: "linux-kernel@vger.kernel.org" Subject: Re: ethtool documentation In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2310 Lines: 60 On Tue, 6 Aug 2002, Dax Kelson wrote: > On Tue, 6 Aug 2002, Richard B. Johnson wrote: > > > If you let a user write to this area, you will allow the user > > to destroy the connectivity on a LAN. > > > > Because of this, there is no such thing as 'unused eeprom space' in > > the Ethernet Controllers. Be careful about putting this weapon in > > the hands of the 'public'. All you need is for one Linux Machine > > on a LAN to end up with the same IEEE Station Address as another > > on that LAN and connectivity to everything on that segment will > > stop. You do this once at an important site and Linux will get a > > very black eye. > > Dick, this "weapon" has been the in the hands of admins and evil-doers for > YEARS! > > It is called /sbin/ifconfig > > With this evil command nearly any NIC can masquerade as any one of > ~281474976710656 possible IEEE Station Addresses. This weapon of > destruction has seen wide spread proliferation across most Unix varients. > Human sacrifice, dogs and cats living together, mass hysteria! > > Err, no wait. > > The sky is not falling, you protest too much. > > Dax Kelson > That capability is not permanent. If you let users write to the SEEPROM, permanently changing the IEEE Station Address, you have let users permanently break their network boards. I do protest when this capability is in the kernel. Anybody, who knows how can, write a driver that can destroy their disk drives, their modems, their audio boards, their screen-cards, their motherboards, ...the list goes on..., because EEPROMS are being used now days. But, you don't put that capability in the kernel as a default. If you do, you get complaints from those who have had the misfortune of being interrogated by lawyers. Also, if you want to destroy Ethernet, mucking with the MAC address is an easy way to do it. Cheers, Dick Johnson Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips). The US military has given us many words, FUBAR, SNAFU, now ENRON. Yes, top management were graduates of West Point and Annapolis. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/