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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 67ACEC433E0 for ; Sun, 2 Aug 2020 18:32:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5500620792 for ; Sun, 2 Aug 2020 18:32:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727063AbgHBScG (ORCPT ); Sun, 2 Aug 2020 14:32:06 -0400 Received: from correo.us.es ([193.147.175.20]:45732 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725917AbgHBScF (ORCPT ); Sun, 2 Aug 2020 14:32:05 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 738FEE4B82 for ; Sun, 2 Aug 2020 20:32:02 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 5DFEBDA791 for ; Sun, 2 Aug 2020 20:32:02 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 53056DA78D; Sun, 2 Aug 2020 20:32:02 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id E5759DA73D; Sun, 2 Aug 2020 20:31:59 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Sun, 02 Aug 2020 20:31:59 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from localhost.localdomain (120.205.137.78.rev.vodafone.pt [78.137.205.120]) (Authenticated sender: pneira@us.es) by entrada.int (Postfix) with ESMTPA id 1E8104265A32; Sun, 2 Aug 2020 20:31:58 +0200 (CEST) X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org Subject: [PATCH 2/7] ipvs: queue delayed work to expire no destination connections if expire_nodest_conn=1 Date: Sun, 2 Aug 2020 20:31:43 +0200 Message-Id: <20200802183149.2808-3-pablo@netfilter.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200802183149.2808-1-pablo@netfilter.org> References: <20200802183149.2808-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Virus-Scanned: ClamAV using ClamSMTP Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Andrew Sy Kim When expire_nodest_conn=1 and a destination is deleted, IPVS does not expire the existing connections until the next matching incoming packet. If there are many connection entries from a single client to a single destination, many packets may get dropped before all the connections are expired (more likely with lots of UDP traffic). An optimization can be made where upon deletion of a destination, IPVS queues up delayed work to immediately expire any connections with a deleted destination. This ensures any reused source ports from a client (within the IPVS timeouts) are scheduled to new real servers instead of silently dropped. Signed-off-by: Andrew Sy Kim Signed-off-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso --- include/net/ip_vs.h | 29 ++++++++++++++++++++ net/netfilter/ipvs/ip_vs_conn.c | 39 +++++++++++++++++++++++++++ net/netfilter/ipvs/ip_vs_core.c | 47 ++++++++++++++------------------- net/netfilter/ipvs/ip_vs_ctl.c | 22 +++++++++++++++ 4 files changed, 110 insertions(+), 27 deletions(-) diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index 011f407b76fe..9a59a33787cb 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -14,6 +14,7 @@ #include /* for struct rwlock_t */ #include /* for struct atomic_t */ #include /* for struct refcount_t */ +#include #include #include @@ -886,6 +887,8 @@ struct netns_ipvs { atomic_t conn_out_counter; #ifdef CONFIG_SYSCTL + /* delayed work for expiring no dest connections */ + struct delayed_work expire_nodest_conn_work; /* 1/rate drop and drop-entry variables */ struct delayed_work defense_work; /* Work handler */ int drop_rate; @@ -1051,6 +1054,11 @@ static inline int sysctl_conn_reuse_mode(struct netns_ipvs *ipvs) return ipvs->sysctl_conn_reuse_mode; } +static inline int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) +{ + return ipvs->sysctl_expire_nodest_conn; +} + static inline int sysctl_schedule_icmp(struct netns_ipvs *ipvs) { return ipvs->sysctl_schedule_icmp; @@ -1138,6 +1146,11 @@ static inline int sysctl_conn_reuse_mode(struct netns_ipvs *ipvs) return 1; } +static inline int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) +{ + return 0; +} + static inline int sysctl_schedule_icmp(struct netns_ipvs *ipvs) { return 0; @@ -1507,6 +1520,22 @@ static inline int ip_vs_todrop(struct netns_ipvs *ipvs) static inline int ip_vs_todrop(struct netns_ipvs *ipvs) { return 0; } #endif +#ifdef CONFIG_SYSCTL +/* Enqueue delayed work for expiring no dest connections + * Only run when sysctl_expire_nodest=1 + */ +static inline void ip_vs_enqueue_expire_nodest_conns(struct netns_ipvs *ipvs) +{ + if (sysctl_expire_nodest_conn(ipvs)) + queue_delayed_work(system_long_wq, + &ipvs->expire_nodest_conn_work, 1); +} + +void ip_vs_expire_nodest_conn_flush(struct netns_ipvs *ipvs); +#else +static inline void ip_vs_enqueue_expire_nodest_conns(struct netns_ipvs *ipvs) {} +#endif + #define IP_VS_DFWD_METHOD(dest) (atomic_read(&(dest)->conn_flags) & \ IP_VS_CONN_F_FWD_MASK) diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c index b3921ae92740..a90b8eac16ac 100644 --- a/net/netfilter/ipvs/ip_vs_conn.c +++ b/net/netfilter/ipvs/ip_vs_conn.c @@ -1389,6 +1389,45 @@ static void ip_vs_conn_flush(struct netns_ipvs *ipvs) goto flush_again; } } + +#ifdef CONFIG_SYSCTL +void ip_vs_expire_nodest_conn_flush(struct netns_ipvs *ipvs) +{ + int idx; + struct ip_vs_conn *cp, *cp_c; + struct ip_vs_dest *dest; + + rcu_read_lock(); + for (idx = 0; idx < ip_vs_conn_tab_size; idx++) { + hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) { + if (cp->ipvs != ipvs) + continue; + + dest = cp->dest; + if (!dest || (dest->flags & IP_VS_DEST_F_AVAILABLE)) + continue; + + if (atomic_read(&cp->n_control)) + continue; + + cp_c = cp->control; + IP_VS_DBG(4, "del connection\n"); + ip_vs_conn_del(cp); + if (cp_c && !atomic_read(&cp_c->n_control)) { + IP_VS_DBG(4, "del controlling connection\n"); + ip_vs_conn_del(cp_c); + } + } + cond_resched_rcu(); + + /* netns clean up started, abort delayed work */ + if (!ipvs->enable) + break; + } + rcu_read_unlock(); +} +#endif + /* * per netns init and exit */ diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index b4a6b7662f3f..e3668a6e54e4 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -694,16 +694,10 @@ static int sysctl_nat_icmp_send(struct netns_ipvs *ipvs) return ipvs->sysctl_nat_icmp_send; } -static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) -{ - return ipvs->sysctl_expire_nodest_conn; -} - #else static int sysctl_snat_reroute(struct netns_ipvs *ipvs) { return 0; } static int sysctl_nat_icmp_send(struct netns_ipvs *ipvs) { return 0; } -static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) { return 0; } #endif @@ -2097,36 +2091,35 @@ ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int } } - if (unlikely(!cp)) { - int v; - - if (!ip_vs_try_to_schedule(ipvs, af, skb, pd, &v, &cp, &iph)) - return v; - } - - IP_VS_DBG_PKT(11, af, pp, skb, iph.off, "Incoming packet"); - /* Check the server status */ - if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) { + if (cp && cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) { /* the destination server is not available */ + if (sysctl_expire_nodest_conn(ipvs)) { + bool old_ct = ip_vs_conn_uses_old_conntrack(cp, skb); - __u32 flags = cp->flags; - - /* when timer already started, silently drop the packet.*/ - if (timer_pending(&cp->timer)) - __ip_vs_conn_put(cp); - else - ip_vs_conn_put(cp); + if (!old_ct) + cp->flags &= ~IP_VS_CONN_F_NFCT; - if (sysctl_expire_nodest_conn(ipvs) && - !(flags & IP_VS_CONN_F_ONE_PACKET)) { - /* try to expire the connection immediately */ ip_vs_conn_expire_now(cp); + __ip_vs_conn_put(cp); + if (old_ct) + return NF_DROP; + cp = NULL; + } else { + __ip_vs_conn_put(cp); + return NF_DROP; } + } - return NF_DROP; + if (unlikely(!cp)) { + int v; + + if (!ip_vs_try_to_schedule(ipvs, af, skb, pd, &v, &cp, &iph)) + return v; } + IP_VS_DBG_PKT(11, af, pp, skb, iph.off, "Incoming packet"); + ip_vs_in_stats(cp, skb); ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd); if (cp->packet_xmit) diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 4af83f466dfc..f984d2c881ff 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -210,6 +210,17 @@ static void update_defense_level(struct netns_ipvs *ipvs) local_bh_enable(); } +/* Handler for delayed work for expiring no + * destination connections + */ +static void expire_nodest_conn_handler(struct work_struct *work) +{ + struct netns_ipvs *ipvs; + + ipvs = container_of(work, struct netns_ipvs, + expire_nodest_conn_work.work); + ip_vs_expire_nodest_conn_flush(ipvs); +} /* * Timer for checking the defense @@ -1164,6 +1175,12 @@ static void __ip_vs_del_dest(struct netns_ipvs *ipvs, struct ip_vs_dest *dest, list_add(&dest->t_list, &ipvs->dest_trash); dest->idle_start = 0; spin_unlock_bh(&ipvs->dest_trash_lock); + + /* Queue up delayed work to expire all no destination connections. + * No-op when CONFIG_SYSCTL is disabled. + */ + if (!cleanup) + ip_vs_enqueue_expire_nodest_conns(ipvs); } @@ -4086,6 +4103,10 @@ static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs) queue_delayed_work(system_long_wq, &ipvs->defense_work, DEFENSE_TIMER_PERIOD); + /* Init delayed work for expiring no dest conn */ + INIT_DELAYED_WORK(&ipvs->expire_nodest_conn_work, + expire_nodest_conn_handler); + return 0; } @@ -4093,6 +4114,7 @@ static void __net_exit ip_vs_control_net_cleanup_sysctl(struct netns_ipvs *ipvs) { struct net *net = ipvs->net; + cancel_delayed_work_sync(&ipvs->expire_nodest_conn_work); cancel_delayed_work_sync(&ipvs->defense_work); cancel_work_sync(&ipvs->defense_work.work); unregister_net_sysctl_table(ipvs->sysctl_hdr); -- 2.20.1