From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757665AbXKTKir (ORCPT ); Tue, 20 Nov 2007 05:38:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752853AbXKTKij (ORCPT ); Tue, 20 Nov 2007 05:38:39 -0500 Received: from mail.univits.se ([212.247.11.167]:6742 "EHLO mail.univits.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751210AbXKTKii (ORCPT ); Tue, 20 Nov 2007 05:38:38 -0500 X-Greylist: delayed 1417 seconds by postgrey-1.27 at vger.kernel.org; Tue, 20 Nov 2007 05:38:38 EST Message-ID: <4742B3A3.2050103@univits.com> Date: Tue, 20 Nov 2007 11:14:59 +0100 From: =?ISO-8859-1?Q?Mikael_St=E5ldal?= User-Agent: Thunderbird 2.0.0.6 (X11/20071022) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Possibility to adjust the only-root-can-bind-to-port-under-1024 limit Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In Linux you have to be root in order to listen to TCP or UDP ports below 1024 (the well-known ports). As far as I know, this limit is hardcoded in the kernel. In some cases, this limit do more harm than good, so it would be nice to be able to adjust it. FreeBSD have a pair of sysctl parameters allowing you to adjust (or effectively remove) this limit, net.inet.ip.portrange.reservedlow and net.inet.ip.portrange.reservedhigh. It would be nice if something similar to net.inet.ip.portrange.reservedhigh was implemented in Linux (with default value 1023). I have no patch for this, since I have never done any kernel hacking before. But it seems like it should be easy to implement by replacing the PROT_SOCK constant with net.inet.ip.portrange.reservedhigh + 1. (See my blog post for a more elaborate discussion about this: http://www.staldal.nu/tech/2007/10/31/why-can-only-root-listen-to-ports-below-1024/) /Mikael