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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 60AECC33CB1 for ; Thu, 16 Jan 2020 11:22:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3AA522073A for ; Thu, 16 Jan 2020 11:22:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726084AbgAPLWx convert rfc822-to-8bit (ORCPT ); Thu, 16 Jan 2020 06:22:53 -0500 Received: from correo.us.es ([193.147.175.20]:57504 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725800AbgAPLWw (ORCPT ); Thu, 16 Jan 2020 06:22:52 -0500 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 6557D191902 for ; Thu, 16 Jan 2020 12:22:50 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 55C0CDA72A for ; Thu, 16 Jan 2020 12:22:50 +0100 (CET) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 4B7B0DA723; Thu, 16 Jan 2020 12:22:50 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 52EC8DA703; Thu, 16 Jan 2020 12:22:48 +0100 (CET) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Thu, 16 Jan 2020 12:22:48 +0100 (CET) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from us.es (unknown [90.77.255.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: 1984lsi) by entrada.int (Postfix) with ESMTPSA id 3624342EE396; Thu, 16 Jan 2020 12:22:48 +0100 (CET) Date: Thu, 16 Jan 2020 12:22:47 +0100 X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: Jeremy Sowden Cc: Netfilter Devel Subject: Re: [PATCH nf-next v4 00/10] netfilter: nft_bitwise: shift support Message-ID: <20200116112247.pfhkhii6b44iiw3n@salvia> References: <20200115213216.77493-1-jeremy@azazel.net> <20200116085133.GG999973@azazel.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <20200116085133.GG999973@azazel.net> User-Agent: NeoMutt/20170113 (1.7.2) X-Virus-Scanned: ClamAV using ClamSMTP Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On Thu, Jan 16, 2020 at 08:51:33AM +0000, Jeremy Sowden wrote: > On 2020-01-15, at 21:32:06 +0000, Jeremy Sowden wrote: > > The connmark xtables extension supports bit-shifts. Add support for > > shifts to nft_bitwise in order to allow nftables to do likewise, e.g.: > > > > nft add rule t c oif lo ct mark set meta mark << 8 | 0xab > > nft add rule t c iif lo meta mark & 0xff 0xab ct mark set meta mark >> 8 > > > > Changes since v3: > > > > * the length of shift values sent by nft may be less than sizeof(u32). > > Actually, having thought about this some more, I believe I had it right > in v3. The difference between v3 and v4 is this: > > @@ -146,7 +146,7 @@ static int nft_bitwise_init_shift(struct nft_bitwise *priv, > tb[NFTA_BITWISE_DATA]); > if (err < 0) > return err; > - if (d.type != NFT_DATA_VALUE || d.len != sizeof(u32) || > + if (d.type != NFT_DATA_VALUE || d.len > sizeof(u32) || > priv->data.data[0] >= BITS_PER_TYPE(u32)) { Why restrict this to 32-bits? > nft_data_release(&priv->data, d.type); > return -EINVAL; > > However, I now think the problem is in userspace and nft should always > send four bytes. If it sends fewer, it makes it more complicated to get > the endianness right. > > Unless you think there are other changes needed that will required a v5, > shall we just ignore v4 and stick with v3?