[NETFILTER]: bridge-nf: filter bridged IPv4/IPv6 encapsulated in pppoe traffic
The attached patch by Michael Milner adds support for using iptables and
ip6tables on bridged traffic encapsulated in ppoe frames, similar to
what's already supported for vlan.
Signed-off-by: Michael Milner <milner@blissisland.ca>
Signed-off-by: Bart De Schuymer <bdschuym@pandora.be>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index fd70d04..9b2986b 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -29,6 +29,8 @@
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
+#include <linux/if_pppox.h>
+#include <linux/ppp_defs.h>
#include <linux/netfilter_bridge.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
@@ -57,8 +59,10 @@
static int brnf_call_ip6tables __read_mostly = 1;
static int brnf_call_arptables __read_mostly = 1;
static int brnf_filter_vlan_tagged __read_mostly = 1;
+static int brnf_filter_pppoe_tagged __read_mostly = 1;
#else
#define brnf_filter_vlan_tagged 1
+#define brnf_filter_pppoe_tagged 1
#endif
static inline __be16 vlan_proto(const struct sk_buff *skb)
@@ -81,6 +85,22 @@
vlan_proto(skb) == htons(ETH_P_ARP) && \
brnf_filter_vlan_tagged)
+static inline __be16 pppoe_proto(const struct sk_buff *skb)
+{
+ return *((__be16 *)(skb_mac_header(skb) + ETH_HLEN +
+ sizeof(struct pppoe_hdr)));
+}
+
+#define IS_PPPOE_IP(skb) \
+ (skb->protocol == htons(ETH_P_PPP_SES) && \
+ pppoe_proto(skb) == htons(PPP_IP) && \
+ brnf_filter_pppoe_tagged)
+
+#define IS_PPPOE_IPV6(skb) \
+ (skb->protocol == htons(ETH_P_PPP_SES) && \
+ pppoe_proto(skb) == htons(PPP_IPV6) && \
+ brnf_filter_pppoe_tagged)
+
/* We need these fake structures to make netfilter happy --
* lots of places assume that skb->dst != NULL, which isn't
* all that unreasonable.
@@ -128,6 +148,8 @@
if (skb->protocol == htons(ETH_P_8021Q))
header_size += VLAN_HLEN;
+ else if (skb->protocol == htons(ETH_P_PPP_SES))
+ header_size += PPPOE_SES_HLEN;
skb_copy_from_linear_data_offset(skb, -header_size,
skb->nf_bridge->data, header_size);
@@ -144,6 +166,8 @@
if (skb->protocol == htons(ETH_P_8021Q))
header_size += VLAN_HLEN;
+ else if (skb->protocol == htons(ETH_P_PPP_SES))
+ header_size += PPPOE_SES_HLEN;
err = skb_cow(skb, header_size);
if (err)
@@ -154,6 +178,8 @@
if (skb->protocol == htons(ETH_P_8021Q))
__skb_push(skb, VLAN_HLEN);
+ else if (skb->protocol == htons(ETH_P_PPP_SES))
+ __skb_push(skb, PPPOE_SES_HLEN);
return 0;
}
@@ -177,6 +203,9 @@
if (skb->protocol == htons(ETH_P_8021Q)) {
skb_push(skb, VLAN_HLEN);
skb->network_header -= VLAN_HLEN;
+ } else if (skb->protocol == htons(ETH_P_PPP_SES)) {
+ skb_push(skb, PPPOE_SES_HLEN);
+ skb->network_header -= PPPOE_SES_HLEN;
}
NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
br_handle_frame_finish, 1);
@@ -258,6 +287,9 @@
if (skb->protocol == htons(ETH_P_8021Q)) {
skb_pull(skb, VLAN_HLEN);
skb->network_header += VLAN_HLEN;
+ } else if (skb->protocol == htons(ETH_P_PPP_SES)) {
+ skb_pull(skb, PPPOE_SES_HLEN);
+ skb->network_header += PPPOE_SES_HLEN;
}
skb->dst->output(skb);
}
@@ -328,6 +360,10 @@
htons(ETH_P_8021Q)) {
skb_push(skb, VLAN_HLEN);
skb->network_header -= VLAN_HLEN;
+ } else if(skb->protocol ==
+ htons(ETH_P_PPP_SES)) {
+ skb_push(skb, PPPOE_SES_HLEN);
+ skb->network_header -= PPPOE_SES_HLEN;
}
NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING,
skb, skb->dev, NULL,
@@ -347,6 +383,9 @@
if (skb->protocol == htons(ETH_P_8021Q)) {
skb_push(skb, VLAN_HLEN);
skb->network_header -= VLAN_HLEN;
+ } else if (skb->protocol == htons(ETH_P_PPP_SES)) {
+ skb_push(skb, PPPOE_SES_HLEN);
+ skb->network_header -= PPPOE_SES_HLEN;
}
NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
br_handle_frame_finish, 1);
@@ -489,7 +528,8 @@
__u32 len;
struct sk_buff *skb = *pskb;
- if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb)) {
+ if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) ||
+ IS_PPPOE_IPV6(skb)) {
#ifdef CONFIG_SYSCTL
if (!brnf_call_ip6tables)
return NF_ACCEPT;
@@ -500,6 +540,9 @@
if (skb->protocol == htons(ETH_P_8021Q)) {
skb_pull_rcsum(skb, VLAN_HLEN);
skb->network_header += VLAN_HLEN;
+ } else if (skb->protocol == htons(ETH_P_PPP_SES)) {
+ skb_pull_rcsum(skb, PPPOE_SES_HLEN);
+ skb->network_header += PPPOE_SES_HLEN;
}
return br_nf_pre_routing_ipv6(hook, skb, in, out, okfn);
}
@@ -508,7 +551,8 @@
return NF_ACCEPT;
#endif
- if (skb->protocol != htons(ETH_P_IP) && !IS_VLAN_IP(skb))
+ if (skb->protocol != htons(ETH_P_IP) && !IS_VLAN_IP(skb) &&
+ !IS_PPPOE_IP(skb))
return NF_ACCEPT;
if ((skb = skb_share_check(*pskb, GFP_ATOMIC)) == NULL)
@@ -517,6 +561,9 @@
if (skb->protocol == htons(ETH_P_8021Q)) {
skb_pull_rcsum(skb, VLAN_HLEN);
skb->network_header += VLAN_HLEN;
+ } else if (skb->protocol == htons(ETH_P_PPP_SES)) {
+ skb_pull_rcsum(skb, PPPOE_SES_HLEN);
+ skb->network_header += PPPOE_SES_HLEN;
}
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
@@ -598,6 +645,9 @@
if (skb->protocol == htons(ETH_P_8021Q)) {
skb_push(skb, VLAN_HLEN);
skb->network_header -= VLAN_HLEN;
+ } else if (skb->protocol == htons(ETH_P_PPP_SES)) {
+ skb_push(skb, PPPOE_SES_HLEN);
+ skb->network_header -= PPPOE_SES_HLEN;
}
NF_HOOK_THRESH(PF_BRIDGE, NF_BR_FORWARD, skb, in,
skb->dev, br_forward_finish, 1);
@@ -626,7 +676,8 @@
if (!parent)
return NF_DROP;
- if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb))
+ if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb) ||
+ IS_PPPOE_IP(skb))
pf = PF_INET;
else
pf = PF_INET6;
@@ -634,6 +685,9 @@
if (skb->protocol == htons(ETH_P_8021Q)) {
skb_pull(*pskb, VLAN_HLEN);
(*pskb)->network_header += VLAN_HLEN;
+ } else if (skb->protocol == htons(ETH_P_PPP_SES)) {
+ skb_pull(*pskb, PPPOE_SES_HLEN);
+ (*pskb)->network_header += PPPOE_SES_HLEN;
}
nf_bridge = skb->nf_bridge;
@@ -726,6 +780,9 @@
if (skb->protocol == htons(ETH_P_8021Q)) {
skb_push(skb, VLAN_HLEN);
skb->network_header -= VLAN_HLEN;
+ } else if (skb->protocol == htons(ETH_P_PPP_SES)) {
+ skb_push(skb, PPPOE_SES_HLEN);
+ skb->network_header -= PPPOE_SES_HLEN;
}
NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, realindev, skb->dev,
@@ -771,7 +828,8 @@
if (!realoutdev)
return NF_DROP;
- if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb))
+ if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb) ||
+ IS_PPPOE_IP(skb))
pf = PF_INET;
else
pf = PF_INET6;
@@ -793,6 +851,9 @@
if (skb->protocol == htons(ETH_P_8021Q)) {
skb_pull(skb, VLAN_HLEN);
skb->network_header += VLAN_HLEN;
+ } else if (skb->protocol == htons(ETH_P_PPP_SES)) {
+ skb_pull(skb, PPPOE_SES_HLEN);
+ skb->network_header += PPPOE_SES_HLEN;
}
nf_bridge_save_header(skb);
@@ -930,6 +991,14 @@
.mode = 0644,
.proc_handler = &brnf_sysctl_call_tables,
},
+ {
+ .ctl_name = NET_BRIDGE_NF_FILTER_PPPOE_TAGGED,
+ .procname = "bridge-nf-filter-pppoe-tagged",
+ .data = &brnf_filter_pppoe_tagged,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &brnf_sysctl_call_tables,
+ },
{ .ctl_name = 0 }
};