From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81D34C41604 for ; Tue, 6 Oct 2020 09:37:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28991206B5 for ; Tue, 6 Oct 2020 09:37:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725943AbgJFJhp (ORCPT ); Tue, 6 Oct 2020 05:37:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725862AbgJFJhp (ORCPT ); Tue, 6 Oct 2020 05:37:45 -0400 Received: from orbyte.nwl.cc (orbyte.nwl.cc [IPv6:2001:41d0:e:133a::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C28DC061755 for ; Tue, 6 Oct 2020 02:37:45 -0700 (PDT) Received: from n0-1 by orbyte.nwl.cc with local (Exim 4.94) (envelope-from ) id 1kPjPk-0007RV-6g; Tue, 06 Oct 2020 11:37:44 +0200 Date: Tue, 6 Oct 2020 11:37:44 +0200 From: Phil Sutter To: Pablo Neira Ayuso Cc: netfilter-devel@vger.kernel.org Subject: Re: [iptables PATCH] nft: Optimize class-based IP prefix matches Message-ID: <20201006093744.GL29050@orbyte.nwl.cc> Mail-Followup-To: Phil Sutter , Pablo Neira Ayuso , netfilter-devel@vger.kernel.org References: <20201002090334.29788-1-phil@nwl.cc> <20201006085621.GA16275@salvia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201006085621.GA16275@salvia> Sender: Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On Tue, Oct 06, 2020 at 10:56:21AM +0200, Pablo Neira Ayuso wrote: > On Fri, Oct 02, 2020 at 11:03:34AM +0200, Phil Sutter wrote: > > Payload expression works on byte-boundaries, leverage this with suitable > > prefix lengths. > > Interesing. But it kicks in the raw payload expression in nftables. > > # nft list ruleset > table ip filter { > chain INPUT { > type filter hook input priority filter; policy accept; > @nh,96,24 8323072 counter packets 0 bytes 0 > } > > Would you send a patch for nftables too? There is already approximate > offset matching in the tree, it should not be too hard to amend. I had a quick look but it didn't seem trivial to me. It is in payload_expr_complete() where a template lookup happens based on expression offset and length which fails due to the unexpected length. Is this the right place to adjust or am I wrong? Strictly speaking, this is just a lack of feature in nftables and nothing breaks due to it. Do you still want to block the iptables change for it? Cheers, Phil