From mboxrd@z Thu Jan 1 00:00:00 1970 From: Werner Almesberger Subject: Re: minimum ICMPv6 message size vs. RPL's DIS Date: Thu, 25 Jul 2013 11:32:23 -0300 Message-ID: <20130725143223.GC29572@ws> References: <20130724232852.GA29572@ws> <20130725061731.GA12365@order.stressinduktion.org> <20130725103048.GB29572@ws> <20130725135820.GB11592@order.stressinduktion.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: netdev@vger.kernel.org, davem@davemloft.net Return-path: Received: from hydra.openmoko.org ([144.76.72.4]:37689 "EHLO hydra.openmoko.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756258Ab3GYOdv (ORCPT ); Thu, 25 Jul 2013 10:33:51 -0400 Content-Disposition: inline In-Reply-To: <20130725135820.GB11592@order.stressinduktion.org> Sender: netdev-owner@vger.kernel.org List-ID: Hannes Frederic Sowa wrote: > I would say no problem. But as I just realized that it could be a bit > problematic because the new defines have actually pretty common names, > let's cc David Miller. Perhaps he has an advice? Yeah, I'll let the issue sit here for a while so that more people can comment. The change has numerous implications, including - there may actually be a minimum size requirement *somewhere* and I just didn't find it, in which case Linux would be right, - name pollution visible to future user space, - subtly changes kernel API semantics for ICMPv6 receivers, to the detriment of those that rely on the kernel to filter messages < 8 bytes and misbehave if exposed to them. So this is definitely not the kind of change I want to rush. Even the pointer fix changes the API in a way that could break applications that currently work (if only on 32 bit platforms, but it's not their fault that things would go wrong on 64 bit), so we can't apply that one before having a decision on the other issue as well. Thanks, - Werner