+ * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev)
+ *
+ * RFC3069 supports proxy arp replies back to the same interface. This
+ * is done to support (ethernet) switch features, like RFC 3069, where
+ * the individual ports are not allowed to communicate with each
+ * other, BUT they are allowed to talk to the upstream router. As
+ * described in RFC 3069, it is possible to allow these hosts to
+ * communicate through the upstream router, by proxy_arp'ing.
+ *
+ * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation"
+ *
+ * This technology is known by different names:
+ * In RFC 3069 it is called VLAN Aggregation.
+ * Cisco and Allied Telesyn call it Private VLAN.
+ * Hewlett-Packard call it Source-Port filtering or port-isolation.
+ * Ericsson call it MAC-Forced Forwarding (RFC Draft).
+ *
+ */
+static inline int arp_fwd_pvlan(struct in_device *in_dev,
+ struct net_device *dev, struct rtable *rt,
+ __be32 sip, __be32 tip)
+{
+ /* Private VLAN is only concerned about the same ethernet segment */
+ if (rt->u.dst.dev != dev)
+ return 0;
+
+ /* Don't reply on self probes (often done by windowz boxes)*/
+ if (sip == tip)
+ return 0;
+
+ if (IN_DEV_PROXY_ARP_PVLAN(in_dev))
+ return 1;
+ else
+ return 0;
+}
+
+/*