ila: Add generic ILA translation facility

This patch implements an ILA tanslation table. This table can be
configured with identifier to locator mappings, and can be be queried
to resolve a mapping. Queries can be parameterized based on interface,
direction (incoming or outoing), and matching locator.  The table is
implemented using rhashtable and is configured via netlink (through
"ip ila .." in iproute).

The table may be used as alternative means to do do ILA tanslations
other than the lw tunnels

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ila.h

@@ -0,0 +1,18 @@
+/*
+ * ILA kernel interface
+ *
+ * Copyright (c) 2015 Tom Herbert <tom@herbertland.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#ifndef _NET_ILA_H
+#define _NET_ILA_H
+
+int ila_xlat_outgoing(struct sk_buff *skb);
+int ila_xlat_incoming(struct sk_buff *skb);
+
+#endif /* _NET_ILA_H */