Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 2636 insertions, 0 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
new file mode 100644
index 00000000..30b88d7b
--- /dev/null
+++ b/net/ipv4/fib_trie.c
@@ -0,0 +1,2636 @@
+/*
+ *   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.
+ *
+ *   Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet
+ *     & Swedish University of Agricultural Sciences.
+ *
+ *   Jens Laas <jens.laas@data.slu.se> Swedish University of
+ *     Agricultural Sciences.
+ *
+ *   Hans Liss <hans.liss@its.uu.se>  Uppsala Universitet
+ *
+ * This work is based on the LPC-trie which is originally described in:
+ *
+ * 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/
+ *
+ *
+ * IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
+ * IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
+ *
+ *
+ * Code from fib_hash has been reused which includes the following header:
+ *
+ *
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		IPv4 FIB: lookup engine and maintenance routines.
+ *
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *		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.
+ *
+ * Substantial contributions to this work comes from:
+ *
+ *		David S. Miller, <davem@davemloft.net>
+ *		Stephen Hemminger <shemminger@osdl.org>
+ *		Paul E. McKenney <paulmck@us.ibm.com>
+ *		Patrick McHardy <kaber@trash.net>
+ */
+
+#define VERSION "0.409"
+
+#include <asm/uaccess.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/proc_fs.h>
+#include <linux/rcupdate.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/prefetch.h>
+#include <linux/export.h>
+#include <net/net_namespace.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <net/ip_fib.h>
+#include "fib_lookup.h"
+
+#define MAX_STAT_DEPTH 32
+
+#define KEYLENGTH (8*sizeof(t_key))
+
+typedef unsigned int t_key;
+
+#define T_TNODE 0
+#define T_LEAF  1
+#define NODE_TYPE_MASK	0x1UL
+#define NODE_TYPE(node) ((node)->parent & NODE_TYPE_MASK)
+
+#define IS_TNODE(n) (!(n->parent & T_LEAF))
+#define IS_LEAF(n) (n->parent & T_LEAF)
+
+struct rt_trie_node {
+	unsigned long parent;
+	t_key key;
+};
+
+struct leaf {
+	unsigned long parent;
+	t_key key;
+	struct hlist_head list;
+	struct rcu_head rcu;
+};
+
+struct leaf_info {
+	struct hlist_node hlist;
+	int plen;
+	u32 mask_plen; /* ntohl(inet_make_mask(plen)) */
+	struct list_head falh;
+	struct rcu_head rcu;
+};
+
+struct tnode {
+	unsigned long parent;
+	t_key key;
+	unsigned char pos;		/* 2log(KEYLENGTH) bits needed */
+	unsigned char bits;		/* 2log(KEYLENGTH) bits needed */
+	unsigned int full_children;	/* KEYLENGTH bits needed */
+	unsigned int empty_children;	/* KEYLENGTH bits needed */
+	union {
+		struct rcu_head rcu;
+		struct work_struct work;
+		struct tnode *tnode_free;
+	};
+	struct rt_trie_node __rcu *child[0];
+};
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+struct trie_use_stats {
+	unsigned int gets;
+	unsigned int backtrack;
+	unsigned int semantic_match_passed;
+	unsigned int semantic_match_miss;
+	unsigned int null_node_hit;
+	unsigned int resize_node_skipped;
+};
+#endif
+
+struct trie_stat {
+	unsigned int totdepth;
+	unsigned int maxdepth;
+	unsigned int tnodes;
+	unsigned int leaves;
+	unsigned int nullpointers;
+	unsigned int prefixes;
+	unsigned int nodesizes[MAX_STAT_DEPTH];
+};
+
+struct trie {
+	struct rt_trie_node __rcu *trie;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+	struct trie_use_stats stats;
+#endif
+};
+
+static void put_child(struct trie *t, struct tnode *tn, int i, struct rt_trie_node *n);
+static void tnode_put_child_reorg(struct tnode *tn, int i, struct rt_trie_node *n,
+				  int wasfull);
+static struct rt_trie_node *resize(struct trie *t, struct tnode *tn);
+static struct tnode *inflate(struct trie *t, struct tnode *tn);
+static struct tnode *halve(struct trie *t, struct tnode *tn);
+/* tnodes to free after resize(); protected by RTNL */
+static struct tnode *tnode_free_head;
+static size_t tnode_free_size;
+
+/*
+ * synchronize_rcu after call_rcu for that many pages; it should be especially
+ * useful before resizing the root node with PREEMPT_NONE configs; the value was
+ * obtained experimentally, aiming to avoid visible slowdown.
+ */
+static const int sync_pages = 128;
+
+static struct kmem_cache *fn_alias_kmem __read_mostly;
+static struct kmem_cache *trie_leaf_kmem __read_mostly;
+
+/*
+ * caller must hold RTNL
+ */
+static inline struct tnode *node_parent(const struct rt_trie_node *node)
+{
+	unsigned long parent;
+
+	parent = rcu_dereference_index_check(node->parent, lockdep_rtnl_is_held());
+
+	return (struct tnode *)(parent & ~NODE_TYPE_MASK);
+}
+
+/*
+ * caller must hold RCU read lock or RTNL
+ */
+static inline struct tnode *node_parent_rcu(const struct rt_trie_node *node)
+{
+	unsigned long parent;
+
+	parent = rcu_dereference_index_check(node->parent, rcu_read_lock_held() ||
+							   lockdep_rtnl_is_held());
+
+	return (struct tnode *)(parent & ~NODE_TYPE_MASK);
+}
+
+/* Same as rcu_assign_pointer
+ * but that macro() assumes that value is a pointer.
+ */
+static inline void node_set_parent(struct rt_trie_node *node, struct tnode *ptr)
+{
+	smp_wmb();
+	node->parent = (unsigned long)ptr | NODE_TYPE(node);
+}
+
+/*
+ * caller must hold RTNL
+ */
+static inline struct rt_trie_node *tnode_get_child(const struct tnode *tn, unsigned int i)
+{
+	BUG_ON(i >= 1U << tn->bits);
+
+	return rtnl_dereference(tn->child[i]);
+}
+
+/*
+ * caller must hold RCU read lock or RTNL
+ */
+static inline struct rt_trie_node *tnode_get_child_rcu(const struct tnode *tn, unsigned int i)
+{
+	BUG_ON(i >= 1U << tn->bits);
+
+	return rcu_dereference_rtnl(tn->child[i]);
+}
+
+static inline int tnode_child_length(const struct tnode *tn)
+{
+	return 1 << tn->bits;
+}
+
+static inline t_key mask_pfx(t_key k, unsigned int l)
+{
+	return (l == 0) ? 0 : k >> (KEYLENGTH-l) << (KEYLENGTH-l);
+}
+
+static inline t_key tkey_extract_bits(t_key a, unsigned int offset, unsigned int bits)
+{
+	if (offset < KEYLENGTH)
+		return ((t_key)(a << offset)) >> (KEYLENGTH - bits);
+	else
+		return 0;
+}
+
+static inline int tkey_equals(t_key a, t_key b)
+{
+	return a == b;
+}
+
+static inline int tkey_sub_equals(t_key a, int offset, int bits, t_key b)
+{
+	if (bits == 0 || offset >= KEYLENGTH)
+		return 1;
+	bits = bits > KEYLENGTH ? KEYLENGTH : bits;
+	return ((a ^ b) << offset) >> (KEYLENGTH - bits) == 0;
+}
+
+static inline int tkey_mismatch(t_key a, int offset, t_key b)
+{
+	t_key diff = a ^ b;
+	int i = offset;
+
+	if (!diff)
+		return 0;
+	while ((diff << i) >> (KEYLENGTH-1) == 0)
+		i++;
+	return i;
+}
+
+/*
+  To understand this stuff, an understanding of keys and all their bits is
+  necessary. Every node in the trie has a key associated with it, but not
+  all of the bits in that key are significant.
+
+  Consider a node 'n' and its parent 'tp'.
+
+  If n is a leaf, every bit in its key is significant. Its presence is
+  necessitated by path compression, since during a tree traversal (when
+  searching for a leaf - unless we are doing an insertion) we will completely
+  ignore all skipped bits we encounter. Thus we need to verify, at the end of
+  a potentially successful search, that we have indeed been walking the
+  correct key path.
+
+  Note that we can never "miss" the correct key in the tree if present by
+  following the wrong path. Path compression ensures that segments of the key
+  that are the same for all keys with a given prefix are skipped, but the
+  skipped part *is* identical for each node in the subtrie below the skipped
+  bit! trie_insert() in this implementation takes care of that - note the
+  call to tkey_sub_equals() in trie_insert().
+
+  if n is an internal node - a 'tnode' here, the various parts of its key
+  have many different meanings.
+
+  Example:
+  _________________________________________________________________
+  | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
+  -----------------------------------------------------------------
+    0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
+
+  _________________________________________________________________
+  | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
+  -----------------------------------------------------------------
+   16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31
+
+  tp->pos = 7
+  tp->bits = 3
+  n->pos = 15
+  n->bits = 4
+
+  First, let's just ignore the bits that come before the parent tp, that is
+  the bits from 0 to (tp->pos-1). They are *known* but at this point we do
+  not use them for anything.
+
+  The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
+  index into the parent's child array. That is, they will be used to find
+  'n' among tp's children.
+
+  The bits from (tp->pos + tp->bits) to (n->pos - 1) - "S" - are skipped bits
+  for the node n.
+
+  All the bits we have seen so far are significant to the node n. The rest
+  of the bits are really not needed or indeed known in n->key.
+
+  The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
+  n's child array, and will of course be different for each child.
+
+
+  The rest of the bits, from (n->pos + n->bits) onward, are completely unknown
+  at this point.
+
+*/
+
+static inline void check_tnode(const struct tnode *tn)
+{
+	WARN_ON(tn && tn->pos+tn->bits > 32);
+}
+
+static const int halve_threshold = 25;
+static const int inflate_threshold = 50;
+static const int halve_threshold_root = 15;
+static const int inflate_threshold_root = 30;
+
+static void __alias_free_mem(struct rcu_head *head)
+{
+	struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
+	kmem_cache_free(fn_alias_kmem, fa);
+}
+
+static inline void alias_free_mem_rcu(struct fib_alias *fa)
+{
+	call_rcu(&fa->rcu, __alias_free_mem);
+}
+
+static void __leaf_free_rcu(struct rcu_head *head)
+{
+	struct leaf *l = container_of(head, struct leaf, rcu);
+	kmem_cache_free(trie_leaf_kmem, l);
+}
+
+static inline void free_leaf(struct leaf *l)
+{
+	call_rcu_bh(&l->rcu, __leaf_free_rcu);
+}
+
+static inline void free_leaf_info(struct leaf_info *leaf)
+{
+	kfree_rcu(leaf, rcu);
+}
+
+static struct tnode *tnode_alloc(size_t size)
+{
+	if (size <= PAGE_SIZE)
+		return kzalloc(size, GFP_KERNEL);
+	else
+		return vzalloc(size);
+}
+
+static void __tnode_vfree(struct work_struct *arg)
+{
+	struct tnode *tn = container_of(arg, struct tnode, work);
+	vfree(tn);
+}
+
+static void __tnode_free_rcu(struct rcu_head *head)
+{
+	struct tnode *tn = container_of(head, struct tnode, rcu);
+	size_t size = sizeof(struct tnode) +
+		      (sizeof(struct rt_trie_node *) << tn->bits);
+
+	if (size <= PAGE_SIZE)
+		kfree(tn);
+	else {
+		INIT_WORK(&tn->work, __tnode_vfree);
+		schedule_work(&tn->work);
+	}
+}
+
+static inline void tnode_free(struct tnode *tn)
+{
+	if (IS_LEAF(tn))
+		free_leaf((struct leaf *) tn);
+	else
+		call_rcu(&tn->rcu, __tnode_free_rcu);
+}
+
+static void tnode_free_safe(struct tnode *tn)
+{
+	BUG_ON(IS_LEAF(tn));
+	tn->tnode_free = tnode_free_head;
+	tnode_free_head = tn;
+	tnode_free_size += sizeof(struct tnode) +
+			   (sizeof(struct rt_trie_node *) << tn->bits);
+}
+
+static void tnode_free_flush(void)
+{
+	struct tnode *tn;
+
+	while ((tn = tnode_free_head)) {
+		tnode_free_head = tn->tnode_free;
+		tn->tnode_free = NULL;
+		tnode_free(tn);
+	}
+
+	if (tnode_free_size >= PAGE_SIZE * sync_pages) {
+		tnode_free_size = 0;
+		synchronize_rcu();
+	}
+}
+
+static struct leaf *leaf_new(void)
+{
+	struct leaf *l = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
+	if (l) {
+		l->parent = T_LEAF;
+		INIT_HLIST_HEAD(&l->list);
+	}
+	return l;
+}
+
+static struct leaf_info *leaf_info_new(int plen)
+{
+	struct leaf_info *li = kmalloc(sizeof(struct leaf_info),  GFP_KERNEL);
+	if (li) {
+		li->plen = plen;
+		li->mask_plen = ntohl(inet_make_mask(plen));
+		INIT_LIST_HEAD(&li->falh);
+	}
+	return li;
+}
+
+static struct tnode *tnode_new(t_key key, int pos, int bits)
+{
+	size_t sz = sizeof(struct tnode) + (sizeof(struct rt_trie_node *) << bits);
+	struct tnode *tn = tnode_alloc(sz);
+
+	if (tn) {
+		tn->parent = T_TNODE;
+		tn->pos = pos;
+		tn->bits = bits;
+		tn->key = key;
+		tn->full_children = 0;
+		tn->empty_children = 1<<bits;
+	}
+
+	pr_debug("AT %p s=%zu %zu\n", tn, sizeof(struct tnode),
+		 sizeof(struct rt_trie_node) << bits);
+	return tn;
+}
+
+/*
+ * Check whether a tnode 'n' is "full", i.e. it is an internal node
+ * and no bits are skipped. See discussion in dyntree paper p. 6
+ */
+
+static inline int tnode_full(const struct tnode *tn, const struct rt_trie_node *n)
+{
+	if (n == NULL || IS_LEAF(n))
+		return 0;
+
+	return ((struct tnode *) n)->pos == tn->pos + tn->bits;
+}
+
+static inline void put_child(struct trie *t, struct tnode *tn, int i,
+			     struct rt_trie_node *n)
+{
+	tnode_put_child_reorg(tn, i, n, -1);
+}
+
+ /*
+  * Add a child at position i overwriting the old value.
+  * Update the value of full_children and empty_children.
+  */
+
+static void tnode_put_child_reorg(struct tnode *tn, int i, struct rt_trie_node *n,
+				  int wasfull)
+{
+	struct rt_trie_node *chi = rtnl_dereference(tn->child[i]);
+	int isfull;
+
+	BUG_ON(i >= 1<<tn->bits);
+
+	/* update emptyChildren */
+	if (n == NULL && chi != NULL)
+		tn->empty_children++;
+	else if (n != NULL && chi == NULL)
+		tn->empty_children--;
+
+	/* update fullChildren */
+	if (wasfull == -1)
+		wasfull = tnode_full(tn, chi);
+
+	isfull = tnode_full(tn, n);
+	if (wasfull && !isfull)
+		tn->full_children--;
+	else if (!wasfull && isfull)
+		tn->full_children++;
+
+	if (n)
+		node_set_parent(n, tn);
+
+	rcu_assign_pointer(tn->child[i], n);
+}
+
+#define MAX_WORK 10
+static struct rt_trie_node *resize(struct trie *t, struct tnode *tn)
+{
+	int i;
+	struct tnode *old_tn;
+	int inflate_threshold_use;
+	int halve_threshold_use;
+	int max_work;
+
+	if (!tn)
+		return NULL;
+
+	pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
+		 tn, inflate_threshold, halve_threshold);
+
+	/* No children */
+	if (tn->empty_children == tnode_child_length(tn)) {
+		tnode_free_safe(tn);
+		return NULL;
+	}
+	/* One child */
+	if (tn->empty_children == tnode_child_length(tn) - 1)
+		goto one_child;
+	/*
+	 * Double as long as the resulting node has a number of
+	 * nonempty nodes that are above the threshold.
+	 */
+
+	/*
+	 * From "Implementing a dynamic compressed trie" by Stefan Nilsson of
+	 * the Helsinki University of Technology and Matti Tikkanen of Nokia
+	 * Telecommunications, page 6:
+	 * "A node is doubled if the ratio of non-empty children to all
+	 * children in the *doubled* node is at least 'high'."
+	 *
+	 * 'high' in this instance is the variable 'inflate_threshold'. It
+	 * is expressed as a percentage, so we multiply it with
+	 * tnode_child_length() and instead of multiplying by 2 (since the
+	 * child array will be doubled by inflate()) and multiplying
+	 * the left-hand side by 100 (to handle the percentage thing) we
+	 * multiply the left-hand side by 50.
+	 *
+	 * The left-hand side may look a bit weird: tnode_child_length(tn)
+	 * - tn->empty_children is of course the number of non-null children
+	 * in the current node. tn->full_children is the number of "full"
+	 * children, that is non-null tnodes with a skip value of 0.
+	 * All of those will be doubled in the resulting inflated tnode, so
+	 * we just count them one extra time here.
+	 *
+	 * A clearer way to write this would be:
+	 *
+	 * to_be_doubled = tn->full_children;
+	 * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
+	 *     tn->full_children;
+	 *
+	 * new_child_length = tnode_child_length(tn) * 2;
+	 *
+	 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
+	 *      new_child_length;
+	 * if (new_fill_factor >= inflate_threshold)
+	 *
+	 * ...and so on, tho it would mess up the while () loop.
+	 *
+	 * anyway,
+	 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
+	 *      inflate_threshold
+	 *
+	 * avoid a division:
+	 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
+	 *      inflate_threshold * new_child_length
+	 *
+	 * expand not_to_be_doubled and to_be_doubled, and shorten:
+	 * 100 * (tnode_child_length(tn) - tn->empty_children +
+	 *    tn->full_children) >= inflate_threshold * new_child_length
+	 *
+	 * expand new_child_length:
+	 * 100 * (tnode_child_length(tn) - tn->empty_children +
+	 *    tn->full_children) >=
+	 *      inflate_threshold * tnode_child_length(tn) * 2
+	 *
+	 * shorten again:
+	 * 50 * (tn->full_children + tnode_child_length(tn) -
+	 *    tn->empty_children) >= inflate_threshold *
+	 *    tnode_child_length(tn)
+	 *
+	 */
+
+	check_tnode(tn);
+
+	/* Keep root node larger  */
+
+	if (!node_parent((struct rt_trie_node *)tn)) {
+		inflate_threshold_use = inflate_threshold_root;
+		halve_threshold_use = halve_threshold_root;
+	} else {
+		inflate_threshold_use = inflate_threshold;
+		halve_threshold_use = halve_threshold;
+	}
+
+	max_work = MAX_WORK;
+	while ((tn->full_children > 0 &&  max_work-- &&
+		50 * (tn->full_children + tnode_child_length(tn)
+		      - tn->empty_children)
+		>= inflate_threshold_use * tnode_child_length(tn))) {
+
+		old_tn = tn;
+		tn = inflate(t, tn);
+
+		if (IS_ERR(tn)) {
+			tn = old_tn;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+			t->stats.resize_node_skipped++;
+#endif
+			break;
+		}
+	}
+
+	check_tnode(tn);
+
+	/* Return if at least one inflate is run */
+	if (max_work != MAX_WORK)
+		return (struct rt_trie_node *) tn;
+
+	/*
+	 * Halve as long as the number of empty children in this
+	 * node is above threshold.
+	 */
+
+	max_work = MAX_WORK;
+	while (tn->bits > 1 &&  max_work-- &&
+	       100 * (tnode_child_length(tn) - tn->empty_children) <
+	       halve_threshold_use * tnode_child_length(tn)) {
+
+		old_tn = tn;
+		tn = halve(t, tn);
+		if (IS_ERR(tn)) {
+			tn = old_tn;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+			t->stats.resize_node_skipped++;
+#endif
+			break;
+		}
+	}
+
+
+	/* Only one child remains */
+	if (tn->empty_children == tnode_child_length(tn) - 1) {
+one_child:
+		for (i = 0; i < tnode_child_length(tn); i++) {
+			struct rt_trie_node *n;
+
+			n = rtnl_dereference(tn->child[i]);
+			if (!n)
+				continue;
+
+			/* compress one level */
+
+			node_set_parent(n, NULL);
+			tnode_free_safe(tn);
+			return n;
+		}
+	}
+	return (struct rt_trie_node *) tn;
+}
+
+
+static void tnode_clean_free(struct tnode *tn)
+{
+	int i;
+	struct tnode *tofree;
+
+	for (i = 0; i < tnode_child_length(tn); i++) {
+		tofree = (struct tnode *)rtnl_dereference(tn->child[i]);
+		if (tofree)
+			tnode_free(tofree);
+	}
+	tnode_free(tn);
+}
+
+static struct tnode *inflate(struct trie *t, struct tnode *tn)
+{
+	struct tnode *oldtnode = tn;
+	int olen = tnode_child_length(tn);
+	int i;
+
+	pr_debug("In inflate\n");
+
+	tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits + 1);
+
+	if (!tn)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * Preallocate and store tnodes before the actual work so we
+	 * don't get into an inconsistent state if memory allocation
+	 * fails. In case of failure we return the oldnode and  inflate
+	 * of tnode is ignored.
+	 */
+
+	for (i = 0; i < olen; i++) {
+		struct tnode *inode;
+
+		inode = (struct tnode *) tnode_get_child(oldtnode, i);
+		if (inode &&
+		    IS_TNODE(inode) &&
+		    inode->pos == oldtnode->pos + oldtnode->bits &&
+		    inode->bits > 1) {
+			struct tnode *left, *right;
+			t_key m = ~0U << (KEYLENGTH - 1) >> inode->pos;
+
+			left = tnode_new(inode->key&(~m), inode->pos + 1,
+					 inode->bits - 1);
+			if (!left)
+				goto nomem;
+
+			right = tnode_new(inode->key|m, inode->pos + 1,
+					  inode->bits - 1);
+
+			if (!right) {
+				tnode_free(left);
+				goto nomem;
+			}
+
+			put_child(t, tn, 2*i, (struct rt_trie_node *) left);
+			put_child(t, tn, 2*i+1, (struct rt_trie_node *) right);
+		}
+	}
+
+	for (i = 0; i < olen; i++) {
+		struct tnode *inode;
+		struct rt_trie_node *node = tnode_get_child(oldtnode, i);
+		struct tnode *left, *right;
+		int size, j;
+
+		/* An empty child */
+		if (node == NULL)
+			continue;
+
+		/* A leaf or an internal node with skipped bits */
+
+		if (IS_LEAF(node) || ((struct tnode *) node)->pos >
+		   tn->pos + tn->bits - 1) {
+			if (tkey_extract_bits(node->key,
+					      oldtnode->pos + oldtnode->bits,
+					      1) == 0)
+				put_child(t, tn, 2*i, node);
+			else
+				put_child(t, tn, 2*i+1, node);
+			continue;
+		}
+
+		/* An internal node with two children */
+		inode = (struct tnode *) node;
+
+		if (inode->bits == 1) {
+			put_child(t, tn, 2*i, rtnl_dereference(inode->child[0]));
+			put_child(t, tn, 2*i+1, rtnl_dereference(inode->child[1]));
+
+			tnode_free_safe(inode);
+			continue;
+		}
+
+		/* An internal node with more than two children */
+
+		/* We will replace this node 'inode' with two new
+		 * ones, 'left' and 'right', each with half of the
+		 * original children. The two new nodes will have
+		 * a position one bit further down the key and this
+		 * means that the "significant" part of their keys
+		 * (see the discussion near the top of this file)
+		 * will differ by one bit, which will be "0" in
+		 * left's key and "1" in right's key. Since we are
+		 * moving the key position by one step, the bit that
+		 * we are moving away from - the bit at position
+		 * (inode->pos) - is the one that will differ between
+		 * left and right. So... we synthesize that bit in the
+		 * two  new keys.
+		 * The mask 'm' below will be a single "one" bit at
+		 * the position (inode->pos)
+		 */
+
+		/* Use the old key, but set the new significant
+		 *   bit to zero.
+		 */
+
+		left = (struct tnode *) tnode_get_child(tn, 2*i);
+		put_child(t, tn, 2*i, NULL);
+
+		BUG_ON(!left);
+
+		right = (struct tnode *) tnode_get_child(tn, 2*i+1);
+		put_child(t, tn, 2*i+1, NULL);
+
+		BUG_ON(!right);
+
+		size = tnode_child_length(left);
+		for (j = 0; j < size; j++) {
+			put_child(t, left, j, rtnl_dereference(inode->child[j]));
+			put_child(t, right, j, rtnl_dereference(inode->child[j + size]));
+		}
+		put_child(t, tn, 2*i, resize(t, left));
+		put_child(t, tn, 2*i+1, resize(t, right));
+
+		tnode_free_safe(inode);
+	}
+	tnode_free_safe(oldtnode);
+	return tn;
+nomem:
+	tnode_clean_free(tn);
+	return ERR_PTR(-ENOMEM);
+}
+
+static struct tnode *halve(struct trie *t, struct tnode *tn)
+{
+	struct tnode *oldtnode = tn;
+	struct rt_trie_node *left, *right;
+	int i;
+	int olen = tnode_child_length(tn);
+
+	pr_debug("In halve\n");
+
+	tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits - 1);
+
+	if (!tn)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * Preallocate and store tnodes before the actual work so we
+	 * don't get into an inconsistent state if memory allocation
+	 * fails. In case of failure we return the oldnode and halve
+	 * of tnode is ignored.
+	 */
+
+	for (i = 0; i < olen; i += 2) {
+		left = tnode_get_child(oldtnode, i);
+		right = tnode_get_child(oldtnode, i+1);
+
+		/* Two nonempty children */
+		if (left && right) {
+			struct tnode *newn;
+
+			newn = tnode_new(left->key, tn->pos + tn->bits, 1);
+
+			if (!newn)
+				goto nomem;
+
+			put_child(t, tn, i/2, (struct rt_trie_node *)newn);
+		}
+
+	}
+
+	for (i = 0; i < olen; i += 2) {
+		struct tnode *newBinNode;
+
+		left = tnode_get_child(oldtnode, i);
+		right = tnode_get_child(oldtnode, i+1);
+
+		/* At least one of the children is empty */
+		if (left == NULL) {
+			if (right == NULL)    /* Both are empty */
+				continue;
+			put_child(t, tn, i/2, right);
+			continue;
+		}
+
+		if (right == NULL) {
+			put_child(t, tn, i/2, left);
+			continue;
+		}
+
+		/* Two nonempty children */
+		newBinNode = (struct tnode *) tnode_get_child(tn, i/2);
+		put_child(t, tn, i/2, NULL);
+		put_child(t, newBinNode, 0, left);
+		put_child(t, newBinNode, 1, right);
+		put_child(t, tn, i/2, resize(t, newBinNode));
+	}
+	tnode_free_safe(oldtnode);
+	return tn;
+nomem:
+	tnode_clean_free(tn);
+	return ERR_PTR(-ENOMEM);
+}
+
+/* readside must use rcu_read_lock currently dump routines
+ via get_fa_head and dump */
+
+static struct leaf_info *find_leaf_info(struct leaf *l, int plen)
+{
+	struct hlist_head *head = &l->list;
+	struct hlist_node *node;
+	struct leaf_info *li;
+
+	hlist_for_each_entry_rcu(li, node, head, hlist)
+		if (li->plen == plen)
+			return li;
+
+	return NULL;
+}
+
+static inline struct list_head *get_fa_head(struct leaf *l, int plen)
+{
+	struct leaf_info *li = find_leaf_info(l, plen);
+
+	if (!li)
+		return NULL;
+
+	return &li->falh;
+}
+
+static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
+{
+	struct leaf_info *li = NULL, *last = NULL;
+	struct hlist_node *node;
+
+	if (hlist_empty(head)) {
+		hlist_add_head_rcu(&new->hlist, head);
+	} else {
+		hlist_for_each_entry(li, node, head, hlist) {
+			if (new->plen > li->plen)
+				break;
+
+			last = li;
+		}
+		if (last)
+			hlist_add_after_rcu(&last->hlist, &new->hlist);
+		else
+			hlist_add_before_rcu(&new->hlist, &li->hlist);
+	}
+}
+
+/* rcu_read_lock needs to be hold by caller from readside */
+
+static struct leaf *
+fib_find_node(struct trie *t, u32 key)
+{
+	int pos;
+	struct tnode *tn;
+	struct rt_trie_node *n;
+
+	pos = 0;
+	n = rcu_dereference_rtnl(t->trie);
+
+	while (n != NULL &&  NODE_TYPE(n) == T_TNODE) {
+		tn = (struct tnode *) n;
+
+		check_tnode(tn);
+
+		if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
+			pos = tn->pos + tn->bits;
+			n = tnode_get_child_rcu(tn,
+						tkey_extract_bits(key,
+								  tn->pos,
+								  tn->bits));
+		} else
+			break;
+	}
+	/* Case we have found a leaf. Compare prefixes */
+
+	if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key))
+		return (struct leaf *)n;
+
+	return NULL;
+}
+
+static void trie_rebalance(struct trie *t, struct tnode *tn)
+{
+	int wasfull;
+	t_key cindex, key;
+	struct tnode *tp;
+
+	key = tn->key;
+
+	while (tn != NULL && (tp = node_parent((struct rt_trie_node *)tn)) != NULL) {
+		cindex = tkey_extract_bits(key, tp->pos, tp->bits);
+		wasfull = tnode_full(tp, tnode_get_child(tp, cindex));
+		tn = (struct tnode *) resize(t, (struct tnode *)tn);
+
+		tnode_put_child_reorg((struct tnode *)tp, cindex,
+				      (struct rt_trie_node *)tn, wasfull);
+
+		tp = node_parent((struct rt_trie_node *) tn);
+		if (!tp)
+			rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+
+		tnode_free_flush();
+		if (!tp)
+			break;
+		tn = tp;
+	}
+
+	/* Handle last (top) tnode */
+	if (IS_TNODE(tn))
+		tn = (struct tnode *)resize(t, (struct tnode *)tn);
+
+	rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+	tnode_free_flush();
+}
+
+/* only used from updater-side */
+
+static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
+{
+	int pos, newpos;
+	struct tnode *tp = NULL, *tn = NULL;
+	struct rt_trie_node *n;
+	struct leaf *l;
+	int missbit;
+	struct list_head *fa_head = NULL;
+	struct leaf_info *li;
+	t_key cindex;
+
+	pos = 0;
+	n = rtnl_dereference(t->trie);
+
+	/* If we point to NULL, stop. Either the tree is empty and we should
+	 * just put a new leaf in if, or we have reached an empty child slot,
+	 * and we should just put our new leaf in that.
+	 * If we point to a T_TNODE, check if it matches our key. Note that
+	 * a T_TNODE might be skipping any number of bits - its 'pos' need
+	 * not be the parent's 'pos'+'bits'!
+	 *
+	 * If it does match the current key, get pos/bits from it, extract
+	 * the index from our key, push the T_TNODE and walk the tree.
+	 *
+	 * If it doesn't, we have to replace it with a new T_TNODE.
+	 *
+	 * If we point to a T_LEAF, it might or might not have the same key
+	 * as we do. If it does, just change the value, update the T_LEAF's
+	 * value, and return it.
+	 * If it doesn't, we need to replace it with a T_TNODE.
+	 */
+
+	while (n != NULL &&  NODE_TYPE(n) == T_TNODE) {
+		tn = (struct tnode *) n;
+
+		check_tnode(tn);
+
+		if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
+			tp = tn;
+			pos = tn->pos + tn->bits;
+			n = tnode_get_child(tn,
+					    tkey_extract_bits(key,
+							      tn->pos,
+							      tn->bits));
+
+			BUG_ON(n && node_parent(n) != tn);
+		} else
+			break;
+	}
+
+	/*
+	 * n  ----> NULL, LEAF or TNODE
+	 *
+	 * tp is n's (parent) ----> NULL or TNODE
+	 */
+
+	BUG_ON(tp && IS_LEAF(tp));
+
+	/* Case 1: n is a leaf. Compare prefixes */
+
+	if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key)) {
+		l = (struct leaf *) n;
+		li = leaf_info_new(plen);
+
+		if (!li)
+			return NULL;
+
+		fa_head = &li->falh;
+		insert_leaf_info(&l->list, li);
+		goto done;
+	}
+	l = leaf_new();
+
+	if (!l)
+		return NULL;
+
+	l->key = key;
+	li = leaf_info_new(plen);
+
+	if (!li) {
+		free_leaf(l);
+		return NULL;
+	}
+
+	fa_head = &li->falh;
+	insert_leaf_info(&l->list, li);
+
+	if (t->trie && n == NULL) {
+		/* Case 2: n is NULL, and will just insert a new leaf */
+
+		node_set_parent((struct rt_trie_node *)l, tp);
+
+		cindex = tkey_extract_bits(key, tp->pos, tp->bits);
+		put_child(t, (struct tnode *)tp, cindex, (struct rt_trie_node *)l);
+	} else {
+		/* Case 3: n is a LEAF or a TNODE and the key doesn't match. */
+		/*
+		 *  Add a new tnode here
+		 *  first tnode need some special handling
+		 */
+
+		if (tp)
+			pos = tp->pos+tp->bits;
+		else
+			pos = 0;
+
+		if (n) {
+			newpos = tkey_mismatch(key, pos, n->key);
+			tn = tnode_new(n->key, newpos, 1);
+		} else {
+			newpos = 0;
+			tn = tnode_new(key, newpos, 1); /* First tnode */
+		}
+
+		if (!tn) {
+			free_leaf_info(li);
+			free_leaf(l);
+			return NULL;
+		}
+
+		node_set_parent((struct rt_trie_node *)tn, tp);
+
+		missbit = tkey_extract_bits(key, newpos, 1);
+		put_child(t, tn, missbit, (struct rt_trie_node *)l);
+		put_child(t, tn, 1-missbit, n);
+
+		if (tp) {
+			cindex = tkey_extract_bits(key, tp->pos, tp->bits);
+			put_child(t, (struct tnode *)tp, cindex,
+				  (struct rt_trie_node *)tn);
+		} else {
+			rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+			tp = tn;
+		}
+	}
+
+	if (tp && tp->pos + tp->bits > 32)
+		pr_warn("fib_trie tp=%p pos=%d, bits=%d, key=%0x plen=%d\n",
+			tp, tp->pos, tp->bits, key, plen);
+
+	/* Rebalance the trie */
+
+	trie_rebalance(t, tp);
+done:
+	return fa_head;
+}
+
+/*
+ * Caller must hold RTNL.
+ */
+int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
+{
+	struct trie *t = (struct trie *) tb->tb_data;
+	struct fib_alias *fa, *new_fa;
+	struct list_head *fa_head = NULL;
+	struct fib_info *fi;
+	int plen = cfg->fc_dst_len;
+	u8 tos = cfg->fc_tos;
+	u32 key, mask;
+	int err;
+	struct leaf *l;
+
+	if (plen > 32)
+		return -EINVAL;
+
+	key = ntohl(cfg->fc_dst);
+
+	pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
+
+	mask = ntohl(inet_make_mask(plen));
+
+	if (key & ~mask)
+		return -EINVAL;
+
+	key = key & mask;
+
+	fi = fib_create_info(cfg);
+	if (IS_ERR(fi)) {
+		err = PTR_ERR(fi);
+		goto err;
+	}
+
+	l = fib_find_node(t, key);
+	fa = NULL;
+
+	if (l) {
+		fa_head = get_fa_head(l, plen);
+		fa = fib_find_alias(fa_head, tos, fi->fib_priority);
+	}
+
+	/* Now fa, if non-NULL, points to the first fib alias
+	 * with the same keys [prefix,tos,priority], if such key already
+	 * exists or to the node before which we will insert new one.
+	 *
+	 * If fa is NULL, we will need to allocate a new one and
+	 * insert to the head of f.
+	 *
+	 * If f is NULL, no fib node matched the destination key
+	 * and we need to allocate a new one of those as well.
+	 */
+
+	if (fa && fa->fa_tos == tos &&
+	    fa->fa_info->fib_priority == fi->fib_priority) {
+		struct fib_alias *fa_first, *fa_match;
+
+		err = -EEXIST;
+		if (cfg->fc_nlflags & NLM_F_EXCL)
+			goto out;
+
+		/* We have 2 goals:
+		 * 1. Find exact match for type, scope, fib_info to avoid
+		 * duplicate routes
+		 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
+		 */
+		fa_match = NULL;
+		fa_first = fa;
+		fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
+		list_for_each_entry_continue(fa, fa_head, fa_list) {
+			if (fa->fa_tos != tos)
+				break;
+			if (fa->fa_info->fib_priority != fi->fib_priority)
+				break;
+			if (fa->fa_type == cfg->fc_type &&
+			    fa->fa_info == fi) {
+				fa_match = fa;
+				break;
+			}
+		}
+
+		if (cfg->fc_nlflags & NLM_F_REPLACE) {
+			struct fib_info *fi_drop;
+			u8 state;
+
+			fa = fa_first;
+			if (fa_match) {
+				if (fa == fa_match)
+					err = 0;
+				goto out;
+			}
+			err = -ENOBUFS;
+			new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
+			if (new_fa == NULL)
+				goto out;
+
+			fi_drop = fa->fa_info;
+			new_fa->fa_tos = fa->fa_tos;
+			new_fa->fa_info = fi;
+			new_fa->fa_type = cfg->fc_type;
+			state = fa->fa_state;
+			new_fa->fa_state = state & ~FA_S_ACCESSED;
+
+			list_replace_rcu(&fa->fa_list, &new_fa->fa_list);
+			alias_free_mem_rcu(fa);
+
+			fib_release_info(fi_drop);
+			if (state & FA_S_ACCESSED)
+				rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
+			rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
+				tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE);
+
+			goto succeeded;
+		}
+		/* Error if we find a perfect match which
+		 * uses the same scope, type, and nexthop
+		 * information.
+		 */
+		if (fa_match)
+			goto out;
+
+		if (!(cfg->fc_nlflags & NLM_F_APPEND))
+			fa = fa_first;
+	}
+	err = -ENOENT;
+	if (!(cfg->fc_nlflags & NLM_F_CREATE))
+		goto out;
+
+	err = -ENOBUFS;
+	new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
+	if (new_fa == NULL)
+		goto out;
+
+	new_fa->fa_info = fi;
+	new_fa->fa_tos = tos;
+	new_fa->fa_type = cfg->fc_type;
+	new_fa->fa_state = 0;
+	/*
+	 * Insert new entry to the list.
+	 */
+
+	if (!fa_head) {
+		fa_head = fib_insert_node(t, key, plen);
+		if (unlikely(!fa_head)) {
+			err = -ENOMEM;
+			goto out_free_new_fa;
+		}
+	}
+
+	if (!plen)
+		tb->tb_num_default++;
+
+	list_add_tail_rcu(&new_fa->fa_list,
+			  (fa ? &fa->fa_list : fa_head));
+
+	rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
+	rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id,
+		  &cfg->fc_nlinfo, 0);
+succeeded:
+	return 0;
+
+out_free_new_fa:
+	kmem_cache_free(fn_alias_kmem, new_fa);
+out:
+	fib_release_info(fi);
+err:
+	return err;
+}
+
+/* should be called with rcu_read_lock */
+static int check_leaf(struct fib_table *tb, struct trie *t, struct leaf *l,
+		      t_key key,  const struct flowi4 *flp,
+		      struct fib_result *res, int fib_flags)
+{
+	struct leaf_info *li;
+	struct hlist_head *hhead = &l->list;
+	struct hlist_node *node;
+
+	hlist_for_each_entry_rcu(li, node, hhead, hlist) {
+		struct fib_alias *fa;
+
+		if (l->key != (key & li->mask_plen))
+			continue;
+
+		list_for_each_entry_rcu(fa, &li->falh, fa_list) {
+			struct fib_info *fi = fa->fa_info;
+			int nhsel, err;
+
+			if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
+				continue;
+			if (fi->fib_dead)
+				continue;
+			if (fa->fa_info->fib_scope < flp->flowi4_scope)
+				continue;
+			fib_alias_accessed(fa);
+			err = fib_props[fa->fa_type].error;
+			if (err) {
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+				t->stats.semantic_match_passed++;
+#endif
+				return err;
+			}
+			if (fi->fib_flags & RTNH_F_DEAD)
+				continue;
+			for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
+				const struct fib_nh *nh = &fi->fib_nh[nhsel];
+
+				if (nh->nh_flags & RTNH_F_DEAD)
+					continue;
+				if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif)
+					continue;
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+				t->stats.semantic_match_passed++;
+#endif
+				res->prefixlen = li->plen;
+				res->nh_sel = nhsel;
+				res->type = fa->fa_type;
+				res->scope = fa->fa_info->fib_scope;
+				res->fi = fi;
+				res->table = tb;
+				res->fa_head = &li->falh;
+				if (!(fib_flags & FIB_LOOKUP_NOREF))
+					atomic_inc(&fi->fib_clntref);
+				return 0;
+			}
+		}
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+		t->stats.semantic_match_miss++;
+#endif
+	}
+
+	return 1;
+}
+
+int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
+		     struct fib_result *res, int fib_flags)
+{
+	struct trie *t = (struct trie *) tb->tb_data;
+	int ret;
+	struct rt_trie_node *n;
+	struct tnode *pn;
+	unsigned int pos, bits;
+	t_key key = ntohl(flp->daddr);
+	unsigned int chopped_off;
+	t_key cindex = 0;
+	unsigned int current_prefix_length = KEYLENGTH;
+	struct tnode *cn;
+	t_key pref_mismatch;
+
+	rcu_read_lock();
+
+	n = rcu_dereference(t->trie);
+	if (!n)
+		goto failed;
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+	t->stats.gets++;
+#endif
+
+	/* Just a leaf? */
+	if (IS_LEAF(n)) {
+		ret = check_leaf(tb, t, (struct leaf *)n, key, flp, res, fib_flags);
+		goto found;
+	}
+
+	pn = (struct tnode *) n;
+	chopped_off = 0;
+
+	while (pn) {
+		pos = pn->pos;
+		bits = pn->bits;
+
+		if (!chopped_off)
+			cindex = tkey_extract_bits(mask_pfx(key, current_prefix_length),
+						   pos, bits);
+
+		n = tnode_get_child_rcu(pn, cindex);
+
+		if (n == NULL) {
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+			t->stats.null_node_hit++;
+#endif
+			goto backtrace;
+		}
+
+		if (IS_LEAF(n)) {
+			ret = check_leaf(tb, t, (struct leaf *)n, key, flp, res, fib_flags);
+			if (ret > 0)
+				goto backtrace;
+			goto found;
+		}
+
+		cn = (struct tnode *)n;
+
+		/*
+		 * It's a tnode, and we can do some extra checks here if we
+		 * like, to avoid descending into a dead-end branch.
+		 * This tnode is in the parent's child array at index
+		 * key[p_pos..p_pos+p_bits] but potentially with some bits
+		 * chopped off, so in reality the index may be just a
+		 * subprefix, padded with zero at the end.
+		 * We can also take a look at any skipped bits in this
+		 * tnode - everything up to p_pos is supposed to be ok,
+		 * and the non-chopped bits of the index (se previous
+		 * paragraph) are also guaranteed ok, but the rest is
+		 * considered unknown.
+		 *
+		 * The skipped bits are key[pos+bits..cn->pos].
+		 */
+
+		/* If current_prefix_length < pos+bits, we are already doing
+		 * actual prefix  matching, which means everything from
+		 * pos+(bits-chopped_off) onward must be zero along some
+		 * branch of this subtree - otherwise there is *no* valid
+		 * prefix present. Here we can only check the skipped
+		 * bits. Remember, since we have already indexed into the
+		 * parent's child array, we know that the bits we chopped of
+		 * *are* zero.
+		 */
+
+		/* NOTA BENE: Checking only skipped bits
+		   for the new node here */
+
+		if (current_prefix_length < pos+bits) {
+			if (tkey_extract_bits(cn->key, current_prefix_length,
+						cn->pos - current_prefix_length)
+			    || !(cn->child[0]))
+				goto backtrace;
+		}
+
+		/*
+		 * If chopped_off=0, the index is fully validated and we
+		 * only need to look at the skipped bits for this, the new,
+		 * tnode. What we actually want to do is to find out if
+		 * these skipped bits match our key perfectly, or if we will
+		 * have to count on finding a matching prefix further down,
+		 * because if we do, we would like to have some way of
+		 * verifying the existence of such a prefix at this point.
+		 */
+
+		/* The only thing we can do at this point is to verify that
+		 * any such matching prefix can indeed be a prefix to our
+		 * key, and if the bits in the node we are inspecting that
+		 * do not match our key are not ZERO, this cannot be true.
+		 * Thus, find out where there is a mismatch (before cn->pos)
+		 * and verify that all the mismatching bits are zero in the
+		 * new tnode's key.
+		 */
+
+		/*
+		 * Note: We aren't very concerned about the piece of
+		 * the key that precede pn->pos+pn->bits, since these
+		 * have already been checked. The bits after cn->pos
+		 * aren't checked since these are by definition
+		 * "unknown" at this point. Thus, what we want to see
+		 * is if we are about to enter the "prefix matching"
+		 * state, and in that case verify that the skipped
+		 * bits that will prevail throughout this subtree are
+		 * zero, as they have to be if we are to find a
+		 * matching prefix.
+		 */
+
+		pref_mismatch = mask_pfx(cn->key ^ key, cn->pos);
+
+		/*
+		 * In short: If skipped bits in this node do not match
+		 * the search key, enter the "prefix matching"
+		 * state.directly.
+		 */
+		if (pref_mismatch) {
+			int mp = KEYLENGTH - fls(pref_mismatch);
+
+			if (tkey_extract_bits(cn->key, mp, cn->pos - mp) != 0)
+				goto backtrace;
+
+			if (current_prefix_length >= cn->pos)
+				current_prefix_length = mp;
+		}
+
+		pn = (struct tnode *)n; /* Descend */
+		chopped_off = 0;
+		continue;
+
+backtrace:
+		chopped_off++;
+
+		/* As zero don't change the child key (cindex) */
+		while ((chopped_off <= pn->bits)
+		       && !(cindex & (1<<(chopped_off-1))))
+			chopped_off++;
+
+		/* Decrease current_... with bits chopped off */
+		if (current_prefix_length > pn->pos + pn->bits - chopped_off)
+			current_prefix_length = pn->pos + pn->bits
+				- chopped_off;
+
+		/*
+		 * Either we do the actual chop off according or if we have
+		 * chopped off all bits in this tnode walk up to our parent.
+		 */
+
+		if (chopped_off <= pn->bits) {
+			cindex &= ~(1 << (chopped_off-1));
+		} else {
+			struct tnode *parent = node_parent_rcu((struct rt_trie_node *) pn);
+			if (!parent)
+				goto failed;
+
+			/* Get Child's index */
+			cindex = tkey_extract_bits(pn->key, parent->pos, parent->bits);
+			pn = parent;
+			chopped_off = 0;
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+			t->stats.backtrack++;
+#endif
+			goto backtrace;
+		}
+	}
+failed:
+	ret = 1;
+found:
+	rcu_read_unlock();
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fib_table_lookup);
+
+/*
+ * Remove the leaf and return parent.
+ */
+static void trie_leaf_remove(struct trie *t, struct leaf *l)
+{
+	struct tnode *tp = node_parent((struct rt_trie_node *) l);
+
+	pr_debug("entering trie_leaf_remove(%p)\n", l);
+
+	if (tp) {
+		t_key cindex = tkey_extract_bits(l->key, tp->pos, tp->bits);
+		put_child(t, (struct tnode *)tp, cindex, NULL);
+		trie_rebalance(t, tp);
+	} else
+		RCU_INIT_POINTER(t->trie, NULL);
+
+	free_leaf(l);
+}
+
+/*
+ * Caller must hold RTNL.
+ */
+int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
+{
+	struct trie *t = (struct trie *) tb->tb_data;
+	u32 key, mask;
+	int plen = cfg->fc_dst_len;
+	u8 tos = cfg->fc_tos;
+	struct fib_alias *fa, *fa_to_delete;
+	struct list_head *fa_head;
+	struct leaf *l;
+	struct leaf_info *li;
+
+	if (plen > 32)
+		return -EINVAL;
+
+	key = ntohl(cfg->fc_dst);
+	mask = ntohl(inet_make_mask(plen));
+
+	if (key & ~mask)
+		return -EINVAL;
+
+	key = key & mask;
+	l = fib_find_node(t, key);
+
+	if (!l)
+		return -ESRCH;
+
+	fa_head = get_fa_head(l, plen);
+	fa = fib_find_alias(fa_head, tos, 0);
+
+	if (!fa)
+		return -ESRCH;
+
+	pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
+
+	fa_to_delete = NULL;
+	fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
+	list_for_each_entry_continue(fa, fa_head, fa_list) {
+		struct fib_info *fi = fa->fa_info;
+
+		if (fa->fa_tos != tos)
+			break;
+
+		if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
+		    (cfg->fc_scope == RT_SCOPE_NOWHERE ||
+		     fa->fa_info->fib_scope == cfg->fc_scope) &&
+		    (!cfg->fc_prefsrc ||
+		     fi->fib_prefsrc == cfg->fc_prefsrc) &&
+		    (!cfg->fc_protocol ||
+		     fi->fib_protocol == cfg->fc_protocol) &&
+		    fib_nh_match(cfg, fi) == 0) {
+			fa_to_delete = fa;
+			break;
+		}
+	}
+
+	if (!fa_to_delete)
+		return -ESRCH;
+
+	fa = fa_to_delete;
+	rtmsg_fib(RTM_DELROUTE, htonl(key), fa, plen, tb->tb_id,
+		  &cfg->fc_nlinfo, 0);
+
+	l = fib_find_node(t, key);
+	li = find_leaf_info(l, plen);
+
+	list_del_rcu(&fa->fa_list);
+
+	if (!plen)
+		tb->tb_num_default--;
+
+	if (list_empty(fa_head)) {
+		hlist_del_rcu(&li->hlist);
+		free_leaf_info(li);
+	}
+
+	if (hlist_empty(&l->list))
+		trie_leaf_remove(t, l);
+
+	if (fa->fa_state & FA_S_ACCESSED)
+		rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
+
+	fib_release_info(fa->fa_info);
+	alias_free_mem_rcu(fa);
+	return 0;
+}
+
+static int trie_flush_list(struct list_head *head)
+{
+	struct fib_alias *fa, *fa_node;
+	int found = 0;
+
+	list_for_each_entry_safe(fa, fa_node, head, fa_list) {
+		struct fib_info *fi = fa->fa_info;
+
+		if (fi && (fi->fib_flags & RTNH_F_DEAD)) {
+			list_del_rcu(&fa->fa_list);
+			fib_release_info(fa->fa_info);
+			alias_free_mem_rcu(fa);
+			found++;
+		}
+	}
+	return found;
+}
+
+static int trie_flush_leaf(struct leaf *l)
+{
+	int found = 0;
+	struct hlist_head *lih = &l->list;
+	struct hlist_node *node, *tmp;
+	struct leaf_info *li = NULL;
+
+	hlist_for_each_entry_safe(li, node, tmp, lih, hlist) {
+		found += trie_flush_list(&li->falh);
+
+		if (list_empty(&li->falh)) {
+			hlist_del_rcu(&li->hlist);
+			free_leaf_info(li);
+		}
+	}
+	return found;
+}
+
+/*
+ * Scan for the next right leaf starting at node p->child[idx]
+ * Since we have back pointer, no recursion necessary.
+ */
+static struct leaf *leaf_walk_rcu(struct tnode *p, struct rt_trie_node *c)
+{
+	do {
+		t_key idx;
+
+		if (c)
+			idx = tkey_extract_bits(c->key, p->pos, p->bits) + 1;
+		else
+			idx = 0;
+
+		while (idx < 1u << p->bits) {
+			c = tnode_get_child_rcu(p, idx++);
+			if (!c)
+				continue;
+
+			if (IS_LEAF(c)) {
+				prefetch(rcu_dereference_rtnl(p->child[idx]));
+				return (struct leaf *) c;
+			}
+
+			/* Rescan start scanning in new node */
+			p = (struct tnode *) c;
+			idx = 0;
+		}
+
+		/* Node empty, walk back up to parent */
+		c = (struct rt_trie_node *) p;
+	} while ((p = node_parent_rcu(c)) != NULL);
+
+	return NULL; /* Root of trie */
+}
+
+static struct leaf *trie_firstleaf(struct trie *t)
+{
+	struct tnode *n = (struct tnode *)rcu_dereference_rtnl(t->trie);
+
+	if (!n)
+		return NULL;
+
+	if (IS_LEAF(n))          /* trie is just a leaf */
+		return (struct leaf *) n;
+
+	return leaf_walk_rcu(n, NULL);
+}
+
+static struct leaf *trie_nextleaf(struct leaf *l)
+{
+	struct rt_trie_node *c = (struct rt_trie_node *) l;
+	struct tnode *p = node_parent_rcu(c);
+
+	if (!p)
+		return NULL;	/* trie with just one leaf */
+
+	return leaf_walk_rcu(p, c);
+}
+
+static struct leaf *trie_leafindex(struct trie *t, int index)
+{
+	struct leaf *l = trie_firstleaf(t);
+
+	while (l && index-- > 0)
+		l = trie_nextleaf(l);
+
+	return l;
+}
+
+
+/*
+ * Caller must hold RTNL.
+ */
+int fib_table_flush(struct fib_table *tb)
+{
+	struct trie *t = (struct trie *) tb->tb_data;
+	struct leaf *l, *ll = NULL;
+	int found = 0;
+
+	for (l = trie_firstleaf(t); l; l = trie_nextleaf(l)) {
+		found += trie_flush_leaf(l);
+
+		if (ll && hlist_empty(&ll->list))
+			trie_leaf_remove(t, ll);
+		ll = l;
+	}
+
+	if (ll && hlist_empty(&ll->list))
+		trie_leaf_remove(t, ll);
+
+	pr_debug("trie_flush found=%d\n", found);
+	return found;
+}
+
+void fib_free_table(struct fib_table *tb)
+{
+	kfree(tb);
+}
+
+static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah,
+			   struct fib_table *tb,
+			   struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int i, s_i;
+	struct fib_alias *fa;
+	__be32 xkey = htonl(key);
+
+	s_i = cb->args[5];
+	i = 0;
+
+	/* rcu_read_lock is hold by caller */
+
+	list_for_each_entry_rcu(fa, fah, fa_list) {
+		if (i < s_i) {
+			i++;
+			continue;
+		}
+
+		if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
+				  cb->nlh->nlmsg_seq,
+				  RTM_NEWROUTE,
+				  tb->tb_id,
+				  fa->fa_type,
+				  xkey,
+				  plen,
+				  fa->fa_tos,
+				  fa->fa_info, NLM_F_MULTI) < 0) {
+			cb->args[5] = i;
+			return -1;
+		}
+		i++;
+	}
+	cb->args[5] = i;
+	return skb->len;
+}
+
+static int fn_trie_dump_leaf(struct leaf *l, struct fib_table *tb,
+			struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct leaf_info *li;
+	struct hlist_node *node;
+	int i, s_i;
+
+	s_i = cb->args[4];
+	i = 0;
+
+	/* rcu_read_lock is hold by caller */
+	hlist_for_each_entry_rcu(li, node, &l->list, hlist) {
+		if (i < s_i) {
+			i++;
+			continue;
+		}
+
+		if (i > s_i)
+			cb->args[5] = 0;
+
+		if (list_empty(&li->falh))
+			continue;
+
+		if (fn_trie_dump_fa(l->key, li->plen, &li->falh, tb, skb, cb) < 0) {
+			cb->args[4] = i;
+			return -1;
+		}
+		i++;
+	}
+
+	cb->args[4] = i;
+	return skb->len;
+}
+
+int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
+		   struct netlink_callback *cb)
+{
+	struct leaf *l;
+	struct trie *t = (struct trie *) tb->tb_data;
+	t_key key = cb->args[2];
+	int count = cb->args[3];
+
+	rcu_read_lock();
+	/* Dump starting at last key.
+	 * Note: 0.0.0.0/0 (ie default) is first key.
+	 */
+	if (count == 0)
+		l = trie_firstleaf(t);
+	else {
+		/* Normally, continue from last key, but if that is missing
+		 * fallback to using slow rescan
+		 */
+		l = fib_find_node(t, key);
+		if (!l)
+			l = trie_leafindex(t, count);
+	}
+
+	while (l) {
+		cb->args[2] = l->key;
+		if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) {
+			cb->args[3] = count;
+			rcu_read_unlock();
+			return -1;
+		}
+
+		++count;
+		l = trie_nextleaf(l);
+		memset(&cb->args[4], 0,
+		       sizeof(cb->args) - 4*sizeof(cb->args[0]));
+	}
+	cb->args[3] = count;
+	rcu_read_unlock();
+
+	return skb->len;
+}
+
+void __init fib_trie_init(void)
+{
+	fn_alias_kmem = kmem_cache_create("ip_fib_alias",
+					  sizeof(struct fib_alias),
+					  0, SLAB_PANIC, NULL);
+
+	trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
+					   max(sizeof(struct leaf),
+					       sizeof(struct leaf_info)),
+					   0, SLAB_PANIC, NULL);
+}
+
+
+struct fib_table *fib_trie_table(u32 id)
+{
+	struct fib_table *tb;
+	struct trie *t;
+
+	tb = kmalloc(sizeof(struct fib_table) + sizeof(struct trie),
+		     GFP_KERNEL);
+	if (tb == NULL)
+		return NULL;
+
+	tb->tb_id = id;
+	tb->tb_default = -1;
+	tb->tb_num_default = 0;
+
+	t = (struct trie *) tb->tb_data;
+	memset(t, 0, sizeof(*t));
+
+	return tb;
+}
+
+#ifdef CONFIG_PROC_FS
+/* Depth first Trie walk iterator */
+struct fib_trie_iter {
+	struct seq_net_private p;
+	struct fib_table *tb;
+	struct tnode *tnode;
+	unsigned int index;
+	unsigned int depth;
+};
+
+static struct rt_trie_node *fib_trie_get_next(struct fib_trie_iter *iter)
+{
+	struct tnode *tn = iter->tnode;
+	unsigned int cindex = iter->index;
+	struct tnode *p;
+
+	/* A single entry routing table */
+	if (!tn)
+		return NULL;
+
+	pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
+		 iter->tnode, iter->index, iter->depth);
+rescan:
+	while (cindex < (1<<tn->bits)) {
+		struct rt_trie_node *n = tnode_get_child_rcu(tn, cindex);
+
+		if (n) {
+			if (IS_LEAF(n)) {
+				iter->tnode = tn;
+				iter->index = cindex + 1;
+			} else {
+				/* push down one level */
+				iter->tnode = (struct tnode *) n;
+				iter->index = 0;
+				++iter->depth;
+			}
+			return n;
+		}
+
+		++cindex;
+	}
+
+	/* Current node exhausted, pop back up */
+	p = node_parent_rcu((struct rt_trie_node *)tn);
+	if (p) {
+		cindex = tkey_extract_bits(tn->key, p->pos, p->bits)+1;
+		tn = p;
+		--iter->depth;
+		goto rescan;
+	}
+
+	/* got root? */
+	return NULL;
+}
+
+static struct rt_trie_node *fib_trie_get_first(struct fib_trie_iter *iter,
+				       struct trie *t)
+{
+	struct rt_trie_node *n;
+
+	if (!t)
+		return NULL;
+
+	n = rcu_dereference(t->trie);
+	if (!n)
+		return NULL;
+
+	if (IS_TNODE(n)) {
+		iter->tnode = (struct tnode *) n;
+		iter->index = 0;
+		iter->depth = 1;
+	} else {
+		iter->tnode = NULL;
+		iter->index = 0;
+		iter->depth = 0;
+	}
+
+	return n;
+}
+
+static void trie_collect_stats(struct trie *t, struct trie_stat *s)
+{
+	struct rt_trie_node *n;
+	struct fib_trie_iter iter;
+
+	memset(s, 0, sizeof(*s));
+
+	rcu_read_lock();
+	for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
+		if (IS_LEAF(n)) {
+			struct leaf *l = (struct leaf *)n;
+			struct leaf_info *li;
+			struct hlist_node *tmp;
+
+			s->leaves++;
+			s->totdepth += iter.depth;
+			if (iter.depth > s->maxdepth)
+				s->maxdepth = iter.depth;
+
+			hlist_for_each_entry_rcu(li, tmp, &l->list, hlist)
+				++s->prefixes;
+		} else {
+			const struct tnode *tn = (const struct tnode *) n;
+			int i;
+
+			s->tnodes++;
+			if (tn->bits < MAX_STAT_DEPTH)
+				s->nodesizes[tn->bits]++;
+
+			for (i = 0; i < (1<<tn->bits); i++)
+				if (!tn->child[i])
+					s->nullpointers++;
+		}
+	}
+	rcu_read_unlock();
+}
+
+/*
+ *	This outputs /proc/net/fib_triestats
+ */
+static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
+{
+	unsigned int i, max, pointers, bytes, avdepth;
+
+	if (stat->leaves)
+		avdepth = stat->totdepth*100 / stat->leaves;
+	else
+		avdepth = 0;
+
+	seq_printf(seq, "\tAver depth:     %u.%02d\n",
+		   avdepth / 100, avdepth % 100);
+	seq_printf(seq, "\tMax depth:      %u\n", stat->maxdepth);
+
+	seq_printf(seq, "\tLeaves:         %u\n", stat->leaves);
+	bytes = sizeof(struct leaf) * stat->leaves;
+
+	seq_printf(seq, "\tPrefixes:       %u\n", stat->prefixes);
+	bytes += sizeof(struct leaf_info) * stat->prefixes;
+
+	seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
+	bytes += sizeof(struct tnode) * stat->tnodes;
+
+	max = MAX_STAT_DEPTH;
+	while (max > 0 && stat->nodesizes[max-1] == 0)
+		max--;
+
+	pointers = 0;
+	for (i = 1; i <= max; i++)
+		if (stat->nodesizes[i] != 0) {
+			seq_printf(seq, "  %u: %u",  i, stat->nodesizes[i]);
+			pointers += (1<<i) * stat->nodesizes[i];
+		}
+	seq_putc(seq, '\n');
+	seq_printf(seq, "\tPointers: %u\n", pointers);
+
+	bytes += sizeof(struct rt_trie_node *) * pointers;
+	seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
+	seq_printf(seq, "Total size: %u  kB\n", (bytes + 1023) / 1024);
+}
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+static void trie_show_usage(struct seq_file *seq,
+			    const struct trie_use_stats *stats)
+{
+	seq_printf(seq, "\nCounters:\n---------\n");
+	seq_printf(seq, "gets = %u\n", stats->gets);
+	seq_printf(seq, "backtracks = %u\n", stats->backtrack);
+	seq_printf(seq, "semantic match passed = %u\n",
+		   stats->semantic_match_passed);
+	seq_printf(seq, "semantic match miss = %u\n",
+		   stats->semantic_match_miss);
+	seq_printf(seq, "null node hit= %u\n", stats->null_node_hit);
+	seq_printf(seq, "skipped node resize = %u\n\n",
+		   stats->resize_node_skipped);
+}
+#endif /*  CONFIG_IP_FIB_TRIE_STATS */
+
+static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
+{
+	if (tb->tb_id == RT_TABLE_LOCAL)
+		seq_puts(seq, "Local:\n");
+	else if (tb->tb_id == RT_TABLE_MAIN)
+		seq_puts(seq, "Main:\n");
+	else
+		seq_printf(seq, "Id %d:\n", tb->tb_id);
+}
+
+
+static int fib_triestat_seq_show(struct seq_file *seq, void *v)
+{
+	struct net *net = (struct net *)seq->private;
+	unsigned int h;
+
+	seq_printf(seq,
+		   "Basic info: size of leaf:"
+		   " %Zd bytes, size of tnode: %Zd bytes.\n",
+		   sizeof(struct leaf), sizeof(struct tnode));
+
+	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+		struct hlist_node *node;
+		struct fib_table *tb;
+
+		hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
+			struct trie *t = (struct trie *) tb->tb_data;
+			struct trie_stat stat;
+
+			if (!t)
+				continue;
+
+			fib_table_print(seq, tb);
+
+			trie_collect_stats(t, &stat);
+			trie_show_stats(seq, &stat);
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+			trie_show_usage(seq, &t->stats);
+#endif
+		}
+	}
+
+	return 0;
+}
+
+static int fib_triestat_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open_net(inode, file, fib_triestat_seq_show);
+}
+
+static const struct file_operations fib_triestat_fops = {
+	.owner	= THIS_MODULE,
+	.open	= fib_triestat_seq_open,
+	.read	= seq_read,
+	.llseek	= seq_lseek,
+	.release = single_release_net,
+};
+
+static struct rt_trie_node *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct fib_trie_iter *iter = seq->private;
+	struct net *net = seq_file_net(seq);
+	loff_t idx = 0;
+	unsigned int h;
+
+	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+		struct hlist_node *node;
+		struct fib_table *tb;
+
+		hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
+			struct rt_trie_node *n;
+
+			for (n = fib_trie_get_first(iter,
+						    (struct trie *) tb->tb_data);
+			     n; n = fib_trie_get_next(iter))
+				if (pos == idx++) {
+					iter->tb = tb;
+					return n;
+				}
+		}
+	}
+
+	return NULL;
+}
+
+static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(RCU)
+{
+	rcu_read_lock();
+	return fib_trie_get_idx(seq, *pos);
+}
+
+static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct fib_trie_iter *iter = seq->private;
+	struct net *net = seq_file_net(seq);
+	struct fib_table *tb = iter->tb;
+	struct hlist_node *tb_node;
+	unsigned int h;
+	struct rt_trie_node *n;
+
+	++*pos;
+	/* next node in same table */
+	n = fib_trie_get_next(iter);
+	if (n)
+		return n;
+
+	/* walk rest of this hash chain */
+	h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
+	while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
+		tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
+		n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
+		if (n)
+			goto found;
+	}
+
+	/* new hash chain */
+	while (++h < FIB_TABLE_HASHSZ) {
+		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+		hlist_for_each_entry_rcu(tb, tb_node, head, tb_hlist) {
+			n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
+			if (n)
+				goto found;
+		}
+	}
+	return NULL;
+
+found:
+	iter->tb = tb;
+	return n;
+}
+
+static void fib_trie_seq_stop(struct seq_file *seq, void *v)
+	__releases(RCU)
+{
+	rcu_read_unlock();
+}
+
+static void seq_indent(struct seq_file *seq, int n)
+{
+	while (n-- > 0)
+		seq_puts(seq, "   ");
+}
+
+static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
+{
+	switch (s) {
+	case RT_SCOPE_UNIVERSE: return "universe";
+	case RT_SCOPE_SITE:	return "site";
+	case RT_SCOPE_LINK:	return "link";
+	case RT_SCOPE_HOST:	return "host";
+	case RT_SCOPE_NOWHERE:	return "nowhere";
+	default:
+		snprintf(buf, len, "scope=%d", s);
+		return buf;
+	}
+}
+
+static const char *const rtn_type_names[__RTN_MAX] = {
+	[RTN_UNSPEC] = "UNSPEC",
+	[RTN_UNICAST] = "UNICAST",
+	[RTN_LOCAL] = "LOCAL",
+	[RTN_BROADCAST] = "BROADCAST",
+	[RTN_ANYCAST] = "ANYCAST",
+	[RTN_MULTICAST] = "MULTICAST",
+	[RTN_BLACKHOLE] = "BLACKHOLE",
+	[RTN_UNREACHABLE] = "UNREACHABLE",
+	[RTN_PROHIBIT] = "PROHIBIT",
+	[RTN_THROW] = "THROW",
+	[RTN_NAT] = "NAT",
+	[RTN_XRESOLVE] = "XRESOLVE",
+};
+
+static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
+{
+	if (t < __RTN_MAX && rtn_type_names[t])
+		return rtn_type_names[t];
+	snprintf(buf, len, "type %u", t);
+	return buf;
+}
+
+/* Pretty print the trie */
+static int fib_trie_seq_show(struct seq_file *seq, void *v)
+{
+	const struct fib_trie_iter *iter = seq->private;
+	struct rt_trie_node *n = v;
+
+	if (!node_parent_rcu(n))
+		fib_table_print(seq, iter->tb);
+
+	if (IS_TNODE(n)) {
+		struct tnode *tn = (struct tnode *) n;
+		__be32 prf = htonl(mask_pfx(tn->key, tn->pos));
+
+		seq_indent(seq, iter->depth-1);
+		seq_printf(seq, "  +-- %pI4/%d %d %d %d\n",
+			   &prf, tn->pos, tn->bits, tn->full_children,
+			   tn->empty_children);
+
+	} else {
+		struct leaf *l = (struct leaf *) n;
+		struct leaf_info *li;
+		struct hlist_node *node;
+		__be32 val = htonl(l->key);
+
+		seq_indent(seq, iter->depth);
+		seq_printf(seq, "  |-- %pI4\n", &val);
+
+		hlist_for_each_entry_rcu(li, node, &l->list, hlist) {
+			struct fib_alias *fa;
+
+			list_for_each_entry_rcu(fa, &li->falh, fa_list) {
+				char buf1[32], buf2[32];
+
+				seq_indent(seq, iter->depth+1);
+				seq_printf(seq, "  /%d %s %s", li->plen,
+					   rtn_scope(buf1, sizeof(buf1),
+						     fa->fa_info->fib_scope),
+					   rtn_type(buf2, sizeof(buf2),
+						    fa->fa_type));
+				if (fa->fa_tos)
+					seq_printf(seq, " tos=%d", fa->fa_tos);
+				seq_putc(seq, '\n');
+			}
+		}
+	}
+
+	return 0;
+}
+
+static const struct seq_operations fib_trie_seq_ops = {
+	.start  = fib_trie_seq_start,
+	.next   = fib_trie_seq_next,
+	.stop   = fib_trie_seq_stop,
+	.show   = fib_trie_seq_show,
+};
+
+static int fib_trie_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open_net(inode, file, &fib_trie_seq_ops,
+			    sizeof(struct fib_trie_iter));
+}
+
+static const struct file_operations fib_trie_fops = {
+	.owner  = THIS_MODULE,
+	.open   = fib_trie_seq_open,
+	.read   = seq_read,
+	.llseek = seq_lseek,
+	.release = seq_release_net,
+};
+
+struct fib_route_iter {
+	struct seq_net_private p;
+	struct trie *main_trie;
+	loff_t	pos;
+	t_key	key;
+};
+
+static struct leaf *fib_route_get_idx(struct fib_route_iter *iter, loff_t pos)
+{
+	struct leaf *l = NULL;
+	struct trie *t = iter->main_trie;
+
+	/* use cache location of last found key */
+	if (iter->pos > 0 && pos >= iter->pos && (l = fib_find_node(t, iter->key)))
+		pos -= iter->pos;
+	else {
+		iter->pos = 0;
+		l = trie_firstleaf(t);
+	}
+
+	while (l && pos-- > 0) {
+		iter->pos++;
+		l = trie_nextleaf(l);
+	}
+
+	if (l)
+		iter->key = pos;	/* remember it */
+	else
+		iter->pos = 0;		/* forget it */
+
+	return l;
+}
+
+static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(RCU)
+{
+	struct fib_route_iter *iter = seq->private;
+	struct fib_table *tb;
+
+	rcu_read_lock();
+	tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
+	if (!tb)
+		return NULL;
+
+	iter->main_trie = (struct trie *) tb->tb_data;
+	if (*pos == 0)
+		return SEQ_START_TOKEN;
+	else
+		return fib_route_get_idx(iter, *pos - 1);
+}
+
+static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct fib_route_iter *iter = seq->private;
+	struct leaf *l = v;
+
+	++*pos;
+	if (v == SEQ_START_TOKEN) {
+		iter->pos = 0;
+		l = trie_firstleaf(iter->main_trie);
+	} else {
+		iter->pos++;
+		l = trie_nextleaf(l);
+	}
+
+	if (l)
+		iter->key = l->key;
+	else
+		iter->pos = 0;
+	return l;
+}
+
+static void fib_route_seq_stop(struct seq_file *seq, void *v)
+	__releases(RCU)
+{
+	rcu_read_unlock();
+}
+
+static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
+{
+	unsigned int flags = 0;
+
+	if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
+		flags = RTF_REJECT;
+	if (fi && fi->fib_nh->nh_gw)
+		flags |= RTF_GATEWAY;
+	if (mask == htonl(0xFFFFFFFF))
+		flags |= RTF_HOST;
+	flags |= RTF_UP;
+	return flags;
+}
+
+/*
+ *	This outputs /proc/net/route.
+ *	The format of the file is not supposed to be changed
+ *	and needs to be same as fib_hash output to avoid breaking
+ *	legacy utilities
+ */
+static int fib_route_seq_show(struct seq_file *seq, void *v)
+{
+	struct leaf *l = v;
+	struct leaf_info *li;
+	struct hlist_node *node;
+
+	if (v == SEQ_START_TOKEN) {
+		seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
+			   "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
+			   "\tWindow\tIRTT");
+		return 0;
+	}
+
+	hlist_for_each_entry_rcu(li, node, &l->list, hlist) {
+		struct fib_alias *fa;
+		__be32 mask, prefix;
+
+		mask = inet_make_mask(li->plen);
+		prefix = htonl(l->key);
+
+		list_for_each_entry_rcu(fa, &li->falh, fa_list) {
+			const struct fib_info *fi = fa->fa_info;
+			unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
+			int len;
+
+			if (fa->fa_type == RTN_BROADCAST
+			    || fa->fa_type == RTN_MULTICAST)
+				continue;
+
+			if (fi)
+				seq_printf(seq,
+					 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
+					 "%d\t%08X\t%d\t%u\t%u%n",
+					 fi->fib_dev ? fi->fib_dev->name : "*",
+					 prefix,
+					 fi->fib_nh->nh_gw, flags, 0, 0,
+					 fi->fib_priority,
+					 mask,
+					 (fi->fib_advmss ?
+					  fi->fib_advmss + 40 : 0),
+					 fi->fib_window,
+					 fi->fib_rtt >> 3, &len);
+			else
+				seq_printf(seq,
+					 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
+					 "%d\t%08X\t%d\t%u\t%u%n",
+					 prefix, 0, flags, 0, 0, 0,
+					 mask, 0, 0, 0, &len);
+
+			seq_printf(seq, "%*s\n", 127 - len, "");
+		}
+	}
+
+	return 0;
+}
+
+static const struct seq_operations fib_route_seq_ops = {
+	.start  = fib_route_seq_start,
+	.next   = fib_route_seq_next,
+	.stop   = fib_route_seq_stop,
+	.show   = fib_route_seq_show,
+};
+
+static int fib_route_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open_net(inode, file, &fib_route_seq_ops,
+			    sizeof(struct fib_route_iter));
+}
+
+static const struct file_operations fib_route_fops = {
+	.owner  = THIS_MODULE,
+	.open   = fib_route_seq_open,
+	.read   = seq_read,
+	.llseek = seq_lseek,
+	.release = seq_release_net,
+};
+
+int __net_init fib_proc_init(struct net *net)
+{
+	if (!proc_net_fops_create(net, "fib_trie", S_IRUGO, &fib_trie_fops))
+		goto out1;
+
+	if (!proc_net_fops_create(net, "fib_triestat", S_IRUGO,
+				  &fib_triestat_fops))
+		goto out2;
+
+	if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_route_fops))
+		goto out3;
+
+	return 0;
+
+out3:
+	proc_net_remove(net, "fib_triestat");
+out2:
+	proc_net_remove(net, "fib_trie");
+out1:
+	return -ENOMEM;
+}
+
+void __net_exit fib_proc_exit(struct net *net)
+{
+	proc_net_remove(net, "fib_trie");
+	proc_net_remove(net, "fib_triestat");
+	proc_net_remove(net, "route");
+}
+
+#endif /* CONFIG_PROC_FS */