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=-2.5 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 C6EA2C06510 for ; Tue, 2 Jul 2019 18:04:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A1C202089C for ; Tue, 2 Jul 2019 18:04:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726529AbfGBSEe (ORCPT ); Tue, 2 Jul 2019 14:04:34 -0400 Received: from orbyte.nwl.cc ([151.80.46.58]:44014 "EHLO orbyte.nwl.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726329AbfGBSEe (ORCPT ); Tue, 2 Jul 2019 14:04:34 -0400 Received: from n0-1 by orbyte.nwl.cc with local (Exim 4.91) (envelope-from ) id 1hiN8q-0004GB-IM; Tue, 02 Jul 2019 20:04:32 +0200 Date: Tue, 2 Jul 2019 20:04:32 +0200 From: Phil Sutter To: Pablo Neira Ayuso Cc: netfilter-devel@vger.kernel.org Subject: Re: [iptables PATCH RFC] nft: Set socket receive buffer Message-ID: <20190702180432.GW31548@orbyte.nwl.cc> Mail-Followup-To: Phil Sutter , Pablo Neira Ayuso , netfilter-devel@vger.kernel.org References: <20190702151201.592-1-phil@nwl.cc> <20190702172615.t4lwms6zu4acq63e@salvia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190702172615.t4lwms6zu4acq63e@salvia> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On Tue, Jul 02, 2019 at 07:26:15PM +0200, Pablo Neira Ayuso wrote: > On Tue, Jul 02, 2019 at 05:12:01PM +0200, Phil Sutter wrote: > > When trying to delete user-defined chains in a large ruleset, > > iptables-nft aborts with "No buffer space available". This can be > > reproduced using the following script: > > > > | #! /bin/bash > > | iptables-nft-restore <( > > | > > | echo "*filter" > > | for i in $(seq 0 200000);do > > | printf ":chain_%06x - [0:0]\n" $i > > | done > > | for i in $(seq 0 200000);do > > | printf -- "-A INPUT -j chain_%06x\n" $i > > | printf -- "-A INPUT -j chain_%06x\n" $i > > | done > > | echo COMMIT > > | > > | ) > > | iptables-nft -X > > > > Note that calling 'iptables-nft -F' before the last call avoids the > > issue. Also, correct behaviour is indicated by a different error > > message, namely: > > > > | iptables v1.8.3 (nf_tables): CHAIN_USER_DEL failed (Device or resource busy): chain chain_000000 > > > > The used multiplier value is a result of trial-and-error, it is the > > first one which eliminated the ENOBUFS condition. > > This is triggering a lots of errors (ack messages) to userspace. > > Could you estimate the buffer size based on the number of commands? > > mnl_batch_talk() is called before iterating over the list of commands, > so this number is already in place. Then, pass it to > mnl_nft_socket_sendmsg(). > > I'd suggest you add a mnl_set_rcvbuffer() too. You could assume that > getpagesize() is the maximum size for an acknoledgment. Ah, I didn't get that kernel reply depends on number of commands sent, not batch size. Thanks for your tip, this seems to work fine! Thanks, Phil