From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: multicasting netlink messages to groups > 31 from userspace Date: Thu, 05 Jul 2007 16:08:12 +0200 Message-ID: <468CFB4C.7040009@trash.net> References: <1183492286.4021.21.camel@johannes.berg> <1183643610.5163.76.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: Johannes Berg , netdev , Thomas Graf To: hadi@cyberus.ca Return-path: Received: from stinky.trash.net ([213.144.137.162]:64851 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756823AbXGEOIg (ORCPT ); Thu, 5 Jul 2007 10:08:36 -0400 In-Reply-To: <1183643610.5163.76.camel@localhost> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org jamal wrote: > >>Looking through the code that uses NL_NONROOT_SEND I just realised that >>it's impossible to send multicast messages from userspace to multicast >>groups with IDs higher than 31. That's not really good given that >>everywhere else we handle multicast groups up to 2^32-1 :/ > > > Yes, this is TheWayItHasBeen(tm). > Patrick had a patch a while back to allow for subscribing to higher > groups because bind() has a similar issue in that it allows you only to > subscribe to the first 32. So it is logical to fix connect, and sendmsg > in a similar fashion. For sendmsg I'd suggest to use cmsgs as in recvmsg().