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=-2.2 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 7F36AC7618F for ; Fri, 19 Jul 2019 16:47:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B9502186A for ; Fri, 19 Jul 2019 16:47:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727876AbfGSQrs (ORCPT ); Fri, 19 Jul 2019 12:47:48 -0400 Received: from mail.us.es ([193.147.175.20]:50516 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726072AbfGSQrr (ORCPT ); Fri, 19 Jul 2019 12:47:47 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 1423ABAEE7 for ; Fri, 19 Jul 2019 18:47:46 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 05631DA4D1 for ; Fri, 19 Jul 2019 18:47:46 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id EF4BEFF6CC; Fri, 19 Jul 2019 18:47:45 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 047C8DA704; Fri, 19 Jul 2019 18:47:44 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Fri, 19 Jul 2019 18:47:44 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from us.es (unknown [47.60.47.94]) (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 C51C04265A2F; Fri, 19 Jul 2019 18:47:43 +0200 (CEST) Date: Fri, 19 Jul 2019 18:47:42 +0200 X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: Michal Kubecek Cc: Florian Westphal , netfilter-devel@vger.kernel.org Subject: Re: userspace conntrack helper and confirming the master conntrack Message-ID: <20190719164742.iasbyklx47sqpw7y@salvia> References: <20190718084943.GE24551@unicorn.suse.cz> <20190718092128.zbw4qappq6jsb4ja@breakpoint.cc> <20190718101806.GF24551@unicorn.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190718101806.GF24551@unicorn.suse.cz> 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, Jul 18, 2019 at 12:18:06PM +0200, Michal Kubecek wrote: > On Thu, Jul 18, 2019 at 11:21:28AM +0200, Florian Westphal wrote: > > > I added some more tracing and this is what seems to happen: > > > > > > - ipv4_confirm() is called for the conntrack from ip_output() via hook > > > - nf_confirm() calls attached helper and calls its help() function > > > which is nfnl_userspace_cthelper(), that returns 0x78003 > > > - nf_confirm() returns that without calling nf_confirm_conntrack() > > > - verdict 0x78003 is returned to nf_hook_slow() which therefore calls > > > nf_queue() to pass this to userspace helper on queue 7 > > > - nf_queue() returns 0 which is also returned by nf_hook_slow() > > > - the packet reappears in nf_reinject() where it passes through > > > nf_reroute() and nf_iterate() to the main switch statement > > > - it takes NF_ACCEPT branch to call okfn which is ip_finish_output() > > > - unless I missed something, there is nothing that could confirm the > > > conntrack after that > > > > I broke this with > > commit 827318feb69cb07ed58bb9b9dd6c2eaa81a116ad > > ("netfilter: conntrack: remove helper hook again"). > > > > Seems we have to revert, i see no other solution at this time. > > Thanks for the quick reply. I can confirm that with commit 827318feb69c > reverted, the helper works as expected. I'll schedule a revert in the next net batch.