[IPV4]: Add LC-Trie FIB lookup algorithm.

Signed-off-by: Robert Olsson <Robert.Olsson@data.slu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/Kconfig

@@ -1,6 +1,32 @@
 #
 # IP configuration
 #
+choice 
+	prompt "Choose IP: FIB lookup""
+	depends on INET
+	default IP_FIB_HASH
+
+config IP_FIB_HASH
+	bool "FIB_HASH"
+	---help---
+	Current FIB is very proven and good enough for most users.
+
+config IP_FIB_TRIE
+	bool "FIB_TRIE"
+	---help---
+	Use new experimental LC-trie as FIB lookup algoritm. 
+        This improves lookup performance
+	
+	LC-trie is described in:
+	
+ 	IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
+ 	IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
+	An experimental study of compression methods for dynamic tries
+ 	Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
+ 	http://www.nada.kth.se/~snilsson/public/papers/dyntrie2/
+       
+endchoice
+
 config IP_MULTICAST
 	bool "IP: multicasting"
 	depends on INET