diff options
author | Florian Westphal <fw@strlen.de> | 2012-03-06 01:22:54 +0000 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2012-03-06 14:43:49 -0500 |
commit | 739e4505a0e8209622dc71743bfa1c804eacf7f4 (patch) | |
tree | df98d368f510e4e58f93e10bb8c77a8f7094b036 | |
parent | a157b9d5b5b626e46eba2ac4e342da8db25cabc4 (diff) |
bridge: netfilter: don't call iptables on vlan packets if sysctl is off
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 <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | 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 84122472656..dec4f381713 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; |