From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Lodal Subject: Re: RFC: Partial IP4 syntax Date: Wed, 29 Sep 2004 18:38:12 +0200 Sender: netfilter-devel-bounces@lists.netfilter.org Message-ID: <415AE4F4.2000903@parknet.dk> References: <415A12AE.1060901@parknet.dk> <415A3263.7080708@xgendev.com> <415A4B4E.1080801@parknet.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Ben Efros , Henrik Nordstrom Return-path: To: netfilter-devel@lists.netfilter.org In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: netfilter-devel-bounces@lists.netfilter.org List-Id: netfilter-devel.vger.kernel.org Henrik Nordstrom skrev: > IETF has not defined such ascii representation of IPv4 addresses, but > the BSD libc inet_aton function does and this has been inherited by very > many systems and tools. > > This notation is being depreated as it does not serve a very useful > purpose and can be somewhat confusing, but it exists and conflicting > with it would be a bad idea. Ok, let's see where we may get compatibility problems: 1) iptables input: iptables' support for full 32bit format addresses is both lacking and undocumented and could disappear without notice. So if any programs use it they should rather be fixed. 2) iptables output: There is a potential problem here, if programs parse iptables or iptables-save output, and they know about the full 32bit form. iptables -L is for human eyes while iptables-save is for machine parsing. So what if we make iptables -L print in any format it likes (not intended for machine parsing anyway), but have iptables-save always print addresses in full dotted quad? >> If it is really a problem I agree my scheme will break it. Could >> probably be solved by changing the default to incomplete-at-beginning, >> so 10 = .10 = 0.0.0.10. > > > Not without breaking existing "industry standards" on how IP numbers can > be typed. Why? I certainly do not want to break anything, formalized or not, only extend. > You could use 10. for the 10.0.0.0/8 network. That is what I propose. The question is how to interpret a single number. Implicitly append or prepend a dot? Or interpret as full 32bit notation? Or ignore it? Simon