From patchwork Tue Mar 10 11:25:55 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 448496 X-Patchwork-Delegate: pablo@netfilter.org Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 253C7140146 for ; Tue, 10 Mar 2015 22:22:16 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751879AbbCJLWP (ORCPT ); Tue, 10 Mar 2015 07:22:15 -0400 Received: from mail.us.es ([193.147.175.20]:36936 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750892AbbCJLWO (ORCPT ); Tue, 10 Mar 2015 07:22:14 -0400 Received: (qmail 20815 invoked from network); 10 Mar 2015 12:22:12 +0100 Received: from unknown (HELO us.es) (192.168.2.12) by us.es with SMTP; 10 Mar 2015 12:22:12 +0100 Received: (qmail 11293 invoked by uid 507); 10 Mar 2015 11:22:12 -0000 X-Qmail-Scanner-Diagnostics: from 127.0.0.1 by antivirus2 (envelope-from , uid 501) with qmail-scanner-2.10 (clamdscan: 0.98.6/20171. spamassassin: 3.4.0. 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Processed in 2.116374 secs); 10 Mar 2015 11:22:12 -0000 X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on antivirus2 X-Spam-Level: X-Spam-Status: No, score=-103.2 required=7.5 tests=BAYES_50,SMTPAUTH_US, USER_IN_WHITELIST autolearn=disabled version=3.4.0 X-Spam-ASN: AS12715 87.216.0.0/16 X-Envelope-From: pablo@netfilter.org Received: from unknown (HELO antivirus2) (127.0.0.1) by us.es with SMTP; 10 Mar 2015 11:22:10 -0000 Received: from 192.168.1.13 (192.168.1.13) by antivirus2 (F-Secure/fsigk_smtp/412/antivirus2); Tue, 10 Mar 2015 12:22:10 +0100 (CET) X-Virus-Status: clean(F-Secure/fsigk_smtp/412/antivirus2) Received: (qmail 7279 invoked from network); 10 Mar 2015 12:22:10 +0100 Received: from 129.166.216.87.static.jazztel.es (HELO salvia.here) (pneira@us.es@87.216.166.129) by mail.us.es with SMTP; 10 Mar 2015 12:22:10 +0100 From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: simon.horman@netronome.com, fw@strlen.de Subject: [PATCH nf-next] netfilter: bridge: use rcu hook to resolve br_netfilter dependency Date: Tue, 10 Mar 2015 12:25:55 +0100 Message-Id: <1425986755-3648-1-git-send-email-pablo@netfilter.org> X-Mailer: git-send-email 1.7.10.4 Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org e5de75b ("netfilter: bridge: move DNAT helper to br_netfilter") results in the following link problem: net/bridge/br_device.c:29: undefined reference to `br_nf_prerouting_finish_bridge` Moreover it creates a hard dependency between br_netfilter and the bridge core, which is what we've been trying to avoid so far. Resolve this problem by using a hook structure so we reduce #ifdef pollution and keep bridge netfilter specific code under br_netfilter.c which was the original intention. Reported-by: Simon Horman Signed-off-by: Pablo Neira Ayuso Reviewed-by: Simon Horman --- net/bridge/br_device.c | 7 ++++++- net/bridge/br_netfilter.c | 9 +++++++-- net/bridge/br_private.h | 10 +++++----- 3 files changed, 18 insertions(+), 8 deletions(-) diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index 294cbcc..4ff77a1 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -25,6 +25,9 @@ #define COMMON_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | \ NETIF_F_GSO_MASK | NETIF_F_HW_CSUM) +const struct nf_br_ops __rcu *nf_br_ops __read_mostly; +EXPORT_SYMBOL_GPL(nf_br_ops); + /* net device transmit always called with BH disabled */ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) { @@ -33,10 +36,12 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) struct net_bridge_fdb_entry *dst; struct net_bridge_mdb_entry *mdst; struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); + const struct nf_br_ops *nf_ops; u16 vid = 0; rcu_read_lock(); - if (br_nf_prerouting_finish_bridge(skb)) { + nf_ops = rcu_dereference(nf_br_ops); + if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) { rcu_read_unlock(); return NETDEV_TX_OK; } diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index a8361c7..b260a97 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -914,7 +914,7 @@ static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb) br_handle_frame_finish(skb); } -int br_nf_prerouting_finish_bridge(struct sk_buff *skb) +static int br_nf_dev_xmit(struct sk_buff *skb) { if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) { br_nf_pre_routing_finish_bridge_slow(skb); @@ -922,7 +922,10 @@ int br_nf_prerouting_finish_bridge(struct sk_buff *skb) } return 0; } -EXPORT_SYMBOL_GPL(br_nf_prerouting_finish_bridge); + +static const struct nf_br_ops br_ops = { + .br_dev_xmit_hook = br_nf_dev_xmit, +}; void br_netfilter_enable(void) { @@ -1061,12 +1064,14 @@ static int __init br_netfilter_init(void) return -ENOMEM; } #endif + RCU_INIT_POINTER(nf_br_ops, &br_ops); printk(KERN_NOTICE "Bridge firewalling registered\n"); return 0; } static void __exit br_netfilter_fini(void) { + RCU_INIT_POINTER(nf_br_ops, NULL); nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); #ifdef CONFIG_SYSCTL unregister_net_sysctl_table(brnf_sysctl_header); diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index d63fc17..7b6e235 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -762,17 +762,17 @@ static inline int br_vlan_enabled(struct net_bridge *br) } #endif +struct nf_br_ops { + int (*br_dev_xmit_hook)(struct sk_buff *skb); +}; +extern const struct nf_br_ops __rcu *nf_br_ops; + /* br_netfilter.c */ #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) -int br_nf_prerouting_finish_bridge(struct sk_buff *skb); int br_nf_core_init(void); void br_nf_core_fini(void); void br_netfilter_rtable_init(struct net_bridge *); #else -static inline int br_nf_prerouting_finish_bridge(struct sk_buff *skb) -{ - return 0; -} static inline int br_nf_core_init(void) { return 0; } static inline void br_nf_core_fini(void) {} #define br_netfilter_rtable_init(x)