[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/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>