From patchwork Mon Mar 5 11:13:40 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 144657 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 6A7BAB7044 for ; Mon, 5 Mar 2012 22:12:33 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756788Ab2CELLp (ORCPT ); Mon, 5 Mar 2012 06:11:45 -0500 Received: from Chamillionaire.breakpoint.cc ([85.10.199.196]:50011 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756857Ab2CELLo (ORCPT ); Mon, 5 Mar 2012 06:11:44 -0500 Received: id: fw by Chamillionaire.breakpoint.cc authenticated by fw with local (easymta 1.00 BETA 1) id 1S4VpP-0005YH-2b; Mon, 05 Mar 2012 12:11:43 +0100 From: Florian Westphal To: netfilter-devel Cc: Florian Westphal Subject: [PATCH v2] bridge: netfilter: don't call iptables on vlan packets if sysctl is off Date: Mon, 5 Mar 2012 12:13:40 +0100 Message-Id: <1330946020-25748-1-git-send-email-fw@strlen.de> X-Mailer: git-send-email 1.7.3.4 Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org When net.bridge.bridge-nf-filter-vlan-tagged is 0 (default), vlan packets arriving should not be sent to ip(6)tables by bridge netfilter. However, it turns out that we currently always send VLAN packets to netfilter, if .. a), CONFIG_VLAN_8021Q is enabled ; or b), CONFIG_VLAN_8021Q is not set but rx vlan offload is enabled on the bridge port. This is because bridge netfilter treats skb with skb->protocol == ETH_P_IP{V6} as "non-vlan packet". With rx vlan offload on or CONFIG_VLAN_8021Q=y, the vlan header has already been removed here, and we cannot rely on skb->protocol alone. Fix this by only using skb->protocol if the skb has no vlan tag, or if a vlan tag is present and filter-vlan-tagged bridge netfilter sysctl is enabled. We cannot remove the skb->protocol == htons(ETH_P_8021Q) test because the vlan tag is still around in the CONFIG_VLAN_8021Q=n && "ethtool -K $itf rxvlan off" case. reproducer: iptables -t raw -I PREROUTING -i br0 iptables -t raw -I PREROUTING -i br0.1 Then send packets to an ip address configured on br0.1 interface. Even with net.bridge.bridge-nf-filter-vlan-tagged=0, the 1st rule will match instead of the 2nd one. With this patch applied, the 2nd rule will match instead. In the non-local address case, netfilter won't be consulted after this patch unless the sysctl is switched on. Signed-off-by: Florian Westphal --- Changes since v1: Keep IS_VLAN_* macros around (requested by Bart De Schuymer) net/bridge/br_netfilter.c | 32 ++++++++++++++++++-------------- 1 files changed, 18 insertions(+), 14 deletions(-) diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 8412247..dec4f38 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -62,6 +62,15 @@ static int brnf_filter_pppoe_tagged __read_mostly = 0; #define brnf_filter_pppoe_tagged 0 #endif +#define IS_IP(skb) \ + (!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_IP)) + +#define IS_IPV6(skb) \ + (!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_IPV6)) + +#define IS_ARP(skb) \ + (!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_ARP)) + static inline __be16 vlan_proto(const struct sk_buff *skb) { if (vlan_tx_tag_present(skb)) @@ -639,8 +648,7 @@ static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff *skb, return NF_DROP; br = p->br; - if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) || - IS_PPPOE_IPV6(skb)) { + if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) { if (!brnf_call_ip6tables && !br->nf_call_ip6tables) return NF_ACCEPT; @@ -651,8 +659,7 @@ static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff *skb, if (!brnf_call_iptables && !br->nf_call_iptables) return NF_ACCEPT; - if (skb->protocol != htons(ETH_P_IP) && !IS_VLAN_IP(skb) && - !IS_PPPOE_IP(skb)) + if (!IS_IP(skb) && !IS_VLAN_IP(skb) && !IS_PPPOE_IP(skb)) return NF_ACCEPT; nf_bridge_pull_encap_header_rcsum(skb); @@ -701,7 +708,7 @@ static int br_nf_forward_finish(struct sk_buff *skb) struct nf_bridge_info *nf_bridge = skb->nf_bridge; struct net_device *in; - if (skb->protocol != htons(ETH_P_ARP) && !IS_VLAN_ARP(skb)) { + if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) { in = nf_bridge->physindev; if (nf_bridge->mask & BRNF_PKT_TYPE) { skb->pkt_type = PACKET_OTHERHOST; @@ -718,6 +725,7 @@ static int br_nf_forward_finish(struct sk_buff *skb) return 0; } + /* This is the 'purely bridged' case. For IP, we pass the packet to * netfilter with indev and outdev set to the bridge device, * but we are still able to filter on the 'real' indev/outdev @@ -744,11 +752,9 @@ static unsigned int br_nf_forward_ip(unsigned int hook, struct sk_buff *skb, if (!parent) return NF_DROP; - if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb) || - IS_PPPOE_IP(skb)) + if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb)) pf = PF_INET; - else if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) || - IS_PPPOE_IPV6(skb)) + else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) pf = PF_INET6; else return NF_ACCEPT; @@ -795,7 +801,7 @@ static unsigned int br_nf_forward_arp(unsigned int hook, struct sk_buff *skb, if (!brnf_call_arptables && !br->nf_call_arptables) return NF_ACCEPT; - if (skb->protocol != htons(ETH_P_ARP)) { + if (!IS_ARP(skb)) { if (!IS_VLAN_ARP(skb)) return NF_ACCEPT; nf_bridge_pull_encap_header(skb); @@ -853,11 +859,9 @@ static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff *skb, if (!realoutdev) return NF_DROP; - if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb) || - IS_PPPOE_IP(skb)) + if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb)) pf = PF_INET; - else if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) || - IS_PPPOE_IPV6(skb)) + else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) pf = PF_INET6; else return NF_ACCEPT;