[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/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 054c515..af6a63a 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1015,7 +1015,12 @@
Default: 1
bridge-nf-filter-vlan-tagged - BOOLEAN
- 1 : pass bridged vlan-tagged ARP/IP traffic to arptables/iptables.
+ 1 : pass bridged vlan-tagged ARP/IP/IPv6 traffic to {arp,ip,ip6}tables.
+ 0 : disable this.
+ Default: 1
+
+bridge-nf-filter-pppoe-tagged - BOOLEAN
+ 1 : pass bridged pppoe-tagged IP/IPv6 traffic to {ip,ip6}tables.
0 : disable this.
Default: 1
diff --git a/include/linux/if_pppox.h b/include/linux/if_pppox.h
index 29d6579..6f987be 100644
--- a/include/linux/if_pppox.h
+++ b/include/linux/if_pppox.h
@@ -111,6 +111,9 @@
struct pppoe_tag tag[0];
} __attribute__ ((packed));
+/* Length of entire PPPoE + PPP header */
+#define PPPOE_SES_HLEN 8
+
#ifdef __KERNEL__
#include <linux/skbuff.h>
diff --git a/include/linux/netfilter_bridge.h b/include/linux/netfilter_bridge.h
index 55689f3..1906003 100644
--- a/include/linux/netfilter_bridge.h
+++ b/include/linux/netfilter_bridge.h
@@ -7,6 +7,7 @@
#include <linux/netfilter.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
+#include <linux/if_pppox.h>
/* Bridge Hooks */
/* After promisc drops, checksum checks. */
@@ -58,8 +59,14 @@
* enough room for the encapsulating header (if there is one). */
static inline int nf_bridge_pad(const struct sk_buff *skb)
{
- return (skb->nf_bridge && skb->protocol == htons(ETH_P_8021Q))
- ? VLAN_HLEN : 0;
+ int padding = 0;
+
+ if (skb->nf_bridge && skb->protocol == htons(ETH_P_8021Q))
+ padding = VLAN_HLEN;
+ else if (skb->nf_bridge && skb->protocol == htons(ETH_P_PPP_SES))
+ padding = PPPOE_SES_HLEN;
+
+ return padding;
}
struct bridge_skb_cb {
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index df2d9ed..47f1c53 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -792,6 +792,7 @@
NET_BRIDGE_NF_CALL_IPTABLES = 2,
NET_BRIDGE_NF_CALL_IP6TABLES = 3,
NET_BRIDGE_NF_FILTER_VLAN_TAGGED = 4,
+ NET_BRIDGE_NF_FILTER_PPPOE_TAGGED = 5,
};
/* CTL_FS names: */
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 }
};