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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A6F5CC433EF for ; Fri, 13 May 2022 21:44:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1384769AbiEMVoB (ORCPT ); Fri, 13 May 2022 17:44:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1384742AbiEMVnw (ORCPT ); Fri, 13 May 2022 17:43:52 -0400 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 082512ED5A; Fri, 13 May 2022 14:43:52 -0700 (PDT) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com Subject: [PATCH net-next 15/17] netfilter: prefer extension check to pointer check Date: Fri, 13 May 2022 23:43:27 +0200 Message-Id: <20220513214329.1136459-16-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220513214329.1136459-1-pablo@netfilter.org> References: <20220513214329.1136459-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org From: Florian Westphal The pointer check usually results in a 'false positive': its likely that the ctnetlink module is loaded but no event monitoring is enabled. After recent change to autodetect ctnetlink usage and only allocate the ecache extension if a listener is active, check if the extension is present on a given conntrack. If its not there, there is nothing to report and calls to the notification framework can be elided. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_core.h | 2 +- include/net/netfilter/nf_conntrack_ecache.h | 31 ++++++++++----------- 2 files changed, 16 insertions(+), 17 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h index 13807ea94cd2..6406cfee34c2 100644 --- a/include/net/netfilter/nf_conntrack_core.h +++ b/include/net/netfilter/nf_conntrack_core.h @@ -60,7 +60,7 @@ static inline int nf_conntrack_confirm(struct sk_buff *skb) if (ct) { if (!nf_ct_is_confirmed(ct)) ret = __nf_conntrack_confirm(skb); - if (likely(ret == NF_ACCEPT)) + if (ret == NF_ACCEPT && nf_ct_ecache_exist(ct)) nf_ct_deliver_cached_events(ct); } return ret; diff --git a/include/net/netfilter/nf_conntrack_ecache.h b/include/net/netfilter/nf_conntrack_ecache.h index 2e3d58439e34..0c1dac318e02 100644 --- a/include/net/netfilter/nf_conntrack_ecache.h +++ b/include/net/netfilter/nf_conntrack_ecache.h @@ -36,6 +36,15 @@ nf_ct_ecache_find(const struct nf_conn *ct) #endif } +static inline bool nf_ct_ecache_exist(const struct nf_conn *ct) +{ +#ifdef CONFIG_NF_CONNTRACK_EVENTS + return nf_ct_ext_exist(ct, NF_CT_EXT_ECACHE); +#else + return false; +#endif +} + #ifdef CONFIG_NF_CONNTRACK_EVENTS /* This structure is passed to event handler */ @@ -108,30 +117,20 @@ nf_conntrack_event_report(enum ip_conntrack_events event, struct nf_conn *ct, u32 portid, int report) { #ifdef CONFIG_NF_CONNTRACK_EVENTS - const struct net *net = nf_ct_net(ct); - - if (!rcu_access_pointer(net->ct.nf_conntrack_event_cb)) - return 0; - - return nf_conntrack_eventmask_report(1 << event, ct, portid, report); -#else - return 0; + if (nf_ct_ecache_exist(ct)) + return nf_conntrack_eventmask_report(1 << event, ct, portid, report); #endif + return 0; } static inline int nf_conntrack_event(enum ip_conntrack_events event, struct nf_conn *ct) { #ifdef CONFIG_NF_CONNTRACK_EVENTS - const struct net *net = nf_ct_net(ct); - - if (!rcu_access_pointer(net->ct.nf_conntrack_event_cb)) - return 0; - - return nf_conntrack_eventmask_report(1 << event, ct, 0, 0); -#else - return 0; + if (nf_ct_ecache_exist(ct)) + return nf_conntrack_eventmask_report(1 << event, ct, 0, 0); #endif + return 0; } #ifdef CONFIG_NF_CONNTRACK_EVENTS -- 2.30.2