From owner-freebsd-net@FreeBSD.ORG Fri Dec 12 10:19:46 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 30C3216A4CE for ; Fri, 12 Dec 2003 10:19:46 -0800 (PST) Received: from pit.databus.com (p70-227.acedsl.com [66.114.70.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id E342743D2D for ; Fri, 12 Dec 2003 10:19:44 -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 hBCIJiiR033574; Fri, 12 Dec 2003 13:19:44 -0500 (EST) (envelope-from barney@pit.databus.com) Received: (from barney@localhost) by pit.databus.com (8.12.10/8.12.10/Submit) id hBCIJisC033573; Fri, 12 Dec 2003 13:19:44 -0500 (EST) (envelope-from barney) Date: Fri, 12 Dec 2003 13:19:44 -0500 From: Barney Wolff To: Brett Glass Message-ID: <20031212181944.GA33245@pit.databus.com> References: <200312120312.UAA10720@lariat.org> <20031212074519.GA23452@pit.databus.com> <6.0.0.22.2.20031212011133.047ae798@localhost> <20031212083522.GA24267@pit.databus.com> <6.0.0.22.2.20031212103142.04611738@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6.0.0.22.2.20031212103142.04611738@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 18:19:46 -0000 On Fri, Dec 12, 2003 at 10:41:50AM -0700, Brett Glass wrote: > At 01:35 AM 12/12/2003, Barney Wolff wrote: > > >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. > > The current algorithm works so long as the blocked ports have > numbers less than 32768. But there are now lots of Trojans and > worms that use higher ports, and admins may want to block them. > So, there ought to be a way to tell libalias "don't assign anything > in this set of ports" -- via a list or a bitmap. How is this problem confined to NAT? Seems to me that any system connecting to the Internet would have the same issue, if it's actually a problem at all. So if I were going to solve it (which I'm not) I would expose the kernel's "pick a high port" function, add hitlist capability, and have libalias use it. -- Barney Wolff http://www.databus.com/bwresume.pdf I'm available by contract or FT, in the NYC metro area or via the 'Net.