From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: [PATCH 08/24] [NETFILTER]: rename NF_ARP to AF_ARP and assign a non-clashing value Date: Thu, 03 Apr 2008 15:17:39 +0200 Message-ID: <47F4D8F3.70606@trash.net> References: <1207134726-28689-1-git-send-email-jengelh@computergmbh.de> <846a3697441043b20a99abac8046aad205938256.1207134547.git.jengelh@computergmbh.de> <47F4C686.2000700@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: netfilter-devel@vger.kernel.org To: Jan Engelhardt Return-path: Received: from stinky.trash.net ([213.144.137.162]:34272 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753850AbYDCNRq (ORCPT ); Thu, 3 Apr 2008 09:17:46 -0400 In-Reply-To: Sender: netfilter-devel-owner@vger.kernel.org List-ID: Jan Engelhardt wrote: > > On Thursday 2008-04-03 13:59, Patrick McHardy wrote: >> Jan Engelhardt wrote: >>> For coming Xtables patches, we want to use AF_UNSPEC, but NF_ARP >>> currently evaluates to the same value so it gets changed. >>> >>> --- a/include/linux/socket.h >>> +++ b/include/linux/socket.h >>> @@ -179,6 +179,7 @@ struct ucred { >>> #define AF_ASH 18 /* Ash */ >>> #define AF_ECONET 19 /* Acorn Econet */ >>> #define AF_ATMSVC 20 /* ATM SVCs */ >>> +#define AF_ARP 21 /* Address Resolution for IPv4 */ >> >> Did you make sure this value wasn't ever used by something else? > > There are no traces of 21 in the entire history [/nico/archive.git, > /tglx/history.git]. > >> Is this used by userspace? If not, why change it? > > Change, because NF_ARP is used to wrongly index into xt_afinfo -- it > overlaps with PF_UNSPEC. Since NF_ARP is only used very internally in > the kernel, it can be changed. To avoid problems, PF_ARP gets a > proper slot. I don't like exporting this since, as you say, userspace doesn't need it and arp isn't an address family. I would suggest to just define something kernel-internally that doesn't clash, like using AF_MAX + X as base.