ipv4: Remove fib_hash.

The time has finally come to remove the hash based routing table
implementation in ipv4.

FIB Trie is mature, well tested, and I've done an audit of it's code
to confirm that it implements insert, delete, and lookup with the same
identical semantics as fib_hash did.

If there are any semantic differences found in fib_trie, we should
simply fix them.

I've placed the trie statistic config option under advanced router
configuration.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>

net/ipv4/Kconfig

@@ -55,45 +55,9 @@ config IP_ADVANCED_ROUTER
 
 	  If unsure, say N here.
 
-choice
-	prompt "Choose IP: FIB lookup algorithm (choose FIB_HASH if unsure)"
-	depends on IP_ADVANCED_ROUTER
-	default ASK_IP_FIB_HASH
-
-config ASK_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 algorithm.
-	  This improves lookup performance if you have a large
-	  number of routes.
-
-	  LC-trie is a longest matching prefix lookup algorithm which
-	  performs better than FIB_HASH for large routing tables.
-	  But, it consumes more memory and is more complex.
-
-	  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.csc.kth.se/~snilsson/software/dyntrie2/>
-
-endchoice
-
-config IP_FIB_HASH
-	def_bool ASK_IP_FIB_HASH || !IP_ADVANCED_ROUTER
-
 config IP_FIB_TRIE_STATS
 	bool "FIB TRIE statistics"
-	depends on IP_FIB_TRIE
+	depends on IP_ADVANCED_ROUTER
 	---help---
 	  Keep track of statistics on structure of FIB TRIE table.
 	  Useful for testing and measuring TRIE performance.

net/ipv4/Makefile

@@ -10,12 +10,10 @@ obj-y     := route.o inetpeer.o protocol.o \
 	     tcp_minisocks.o tcp_cong.o \
 	     datagram.o raw.o udp.o udplite.o \
 	     arp.o icmp.o devinet.o af_inet.o  igmp.o \
-	     fib_frontend.o fib_semantics.o \
+	     fib_frontend.o fib_semantics.o fib_trie.o \
 	     inet_fragment.o
 
 obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o
-obj-$(CONFIG_IP_FIB_HASH) += fib_hash.o
-obj-$(CONFIG_IP_FIB_TRIE) += fib_trie.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_IP_MULTIPLE_TABLES) += fib_rules.o
 obj-$(CONFIG_IP_MROUTE) += ipmr.o