From owner-freebsd-net@FreeBSD.ORG Fri Dec 12 00:35:24 2003 Return-Path: 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 C43B016A4CE for ; Fri, 12 Dec 2003 00:35:24 -0800 (PST) Received: from pit.databus.com (p70-227.acedsl.com [66.114.70.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8B04143D09 for ; Fri, 12 Dec 2003 00:35:23 -0800 (PST) (envelope-from barney@pit.databus.com) Received: from pit.databus.com (localhost [127.0.0.1]) by pit.databus.com (8.12.10/8.12.10) with ESMTP id hBC8ZNiR024672; Fri, 12 Dec 2003 03:35:23 -0500 (EST) (envelope-from barney@pit.databus.com) Received: (from barney@localhost) by pit.databus.com (8.12.10/8.12.10/Submit) id hBC8ZMb7024671; Fri, 12 Dec 2003 03:35:22 -0500 (EST) (envelope-from barney) Date: Fri, 12 Dec 2003 03:35:22 -0500 From: Barney Wolff To: Brett Glass Message-ID: <20031212083522.GA24267@pit.databus.com> References: <200312120312.UAA10720@lariat.org> <20031212074519.GA23452@pit.databus.com> <6.0.0.22.2.20031212011133.047ae798@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6.0.0.22.2.20031212011133.047ae798@localhost> User-Agent: Mutt/1.4.1i X-Scanned-By: MIMEDefang 2.38 cc: net@freebsd.org Subject: Re: Controlling ports used by natd X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Dec 2003 08:35:24 -0000 On Fri, Dec 12, 2003 at 01:19:34AM -0700, Brett Glass wrote: > At 12:45 AM 12/12/2003, Barney Wolff wrote: > > >UTSL libpcap/alias_db.c > > I can find no such file in /usr/src/contrib/libpcap. I did find > one in /usr/src/lib/libalias. It seems to have in it a function > called FindNewPortGroup that hunts for ports at random, but > there's no discipline there to make it avoid specific ports > or groups of ports. Are you suggesting that I modify this > function to add port exclusion as a new feature? I suppose that > I could do this, but it would involve changing data structures > that were used by many programs, including natd and ppp. So, > there could be a huge ripple effect. Oops, sorry for the confusion. How fancy a change is up to you, but changing ALIAS_PORT_BASE and ALIAS_PORT_MASK (and _EVEN) would let you confine the port range without much work. Un-nat'd folks are most likely using ports in the hi range, and usually without trouble - presumably normal programs don't make special checks for trojan ports. -- Barney Wolff http://www.databus.com/bwresume.pdf I'm available by contract or FT, in the NYC metro area or via the 'Net.