[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>

1 files changed, 2454 insertions, 0 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
new file mode 100644
index 000000000000..c0ece94fc63e
--- /dev/null
+++ b/net/ipv4/fib_trie.c
@@ -0,0 +1,2454 @@
+/*
+ *   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 descibed in:
+ * 
+ * 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/
+ *
+ *
+ * IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
+ * IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
+ *
+ * Version:     $Id: fib_trie.c,v 1.3 2005/06/08 14:20:01 robert Exp $
+ *
+ *
+ * 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.
+ */
+
+#define VERSION "0.323"
+
+#include <linux/config.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.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/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/proc_fs.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/init.h>
+#include <linux/list.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"
+
+#undef CONFIG_IP_FIB_TRIE_STATS
+#define MAX_CHILDS 16384
+
+#define EXTRACT(p, n, str) ((str)<<(p)>>(32-(n)))
+#define KEYLENGTH (8*sizeof(t_key))
+#define MASK_PFX(k, l) (((l)==0)?0:(k >> (KEYLENGTH-l)) << (KEYLENGTH-l))
+#define TKEY_GET_MASK(offset, bits) (((bits)==0)?0:((t_key)(-1) << (KEYLENGTH - bits) >> offset))
+
+static DEFINE_RWLOCK(fib_lock);
+
+typedef unsigned int t_key;
+
+#define T_TNODE 0
+#define T_LEAF  1
+#define NODE_TYPE_MASK  0x1UL
+#define NODE_PARENT(_node) \
+((struct tnode *)((_node)->_parent & ~NODE_TYPE_MASK))
+#define NODE_SET_PARENT(_node, _ptr) \
+((_node)->_parent = (((unsigned long)(_ptr)) | \
+                     ((_node)->_parent & NODE_TYPE_MASK)))
+#define NODE_INIT_PARENT(_node, _type) \
+((_node)->_parent = (_type))
+#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 node {
+        t_key key;
+        unsigned long _parent;
+};
+
+struct leaf {
+        t_key key;
+        unsigned long _parent;
+        struct hlist_head list;
+};
+
+struct leaf_info {
+        struct hlist_node hlist;
+        int plen;
+        struct list_head falh;
+};
+
+struct tnode {
+        t_key key;
+        unsigned long _parent;
+        unsigned short pos:5;        /* 2log(KEYLENGTH) bits needed */
+        unsigned short bits:5;       /* 2log(KEYLENGTH) bits needed */
+        unsigned short full_children;  /* KEYLENGTH bits needed */
+        unsigned short empty_children; /* KEYLENGTH bits needed */
+        struct node *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;
+};
+#endif
+
+struct trie_stat {
+        unsigned int totdepth;
+        unsigned int maxdepth;
+        unsigned int tnodes;
+        unsigned int leaves;
+        unsigned int nullpointers;
+        unsigned int nodesizes[MAX_CHILDS];
+};    
+
+struct trie {
+        struct node *trie;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+        struct trie_use_stats stats;
+#endif
+        int size;
+        unsigned int revision;
+};
+
+static int trie_debug = 0;
+
+static int tnode_full(struct tnode *tn, struct node *n);
+static void put_child(struct trie *t, struct tnode *tn, int i, struct node *n);
+static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int wasfull);
+static int tnode_child_length(struct tnode *tn);
+static struct 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);
+static void tnode_free(struct tnode *tn);
+static void trie_dump_seq(struct seq_file *seq, struct trie *t);
+extern struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio);
+extern int fib_detect_death(struct fib_info *fi, int order,
+                            struct fib_info **last_resort, int *last_idx, int *dflt);
+
+extern void rtmsg_fib(int event, u32 key, struct fib_alias *fa, int z, int tb_id,
+               struct nlmsghdr *n, struct netlink_skb_parms *req);
+
+static kmem_cache_t *fn_alias_kmem;
+static struct trie *trie_local = NULL, *trie_main = NULL;
+
+static void trie_bug(char *err)
+{
+        printk("Trie Bug: %s\n", err);
+        BUG();
+}
+
+static inline struct node *tnode_get_child(struct tnode *tn, int i) 
+{
+        if (i >=  1<<tn->bits) 
+                trie_bug("tnode_get_child");
+
+        return tn->child[i];
+}
+
+static inline int tnode_child_length(struct tnode *tn)
+{
+        return 1<<tn->bits;
+}
+
+/*
+  _________________________________________________________________
+  | 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
+  KEYLENGTH=32
+*/
+
+static inline t_key tkey_extract_bits(t_key a, int offset, 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;
+}
+
+/* Candiate for fib_semantics */
+
+static void fn_free_alias(struct fib_alias *fa)
+{
+        fib_release_info(fa->fa_info);
+        kmem_cache_free(fn_alias_kmem, fa);
+}
+
+/*
+  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 
+  necessitaded 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 void check_tnode(struct tnode *tn)
+{
+        if(tn && tn->pos+tn->bits > 32) {
+                printk("TNODE ERROR tn=%p, pos=%d, bits=%d\n", tn, tn->pos, tn->bits);
+        }
+}
+
+static int halve_threshold = 25;
+static int inflate_threshold = 50;
+
+static struct leaf *leaf_new(void)
+{
+        struct leaf *l = kmalloc(sizeof(struct leaf),  GFP_KERNEL);
+        if(l) {
+                NODE_INIT_PARENT(l, 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);
+        li->plen = plen;
+        INIT_LIST_HEAD(&li->falh);
+        return li;
+}
+
+static inline void free_leaf(struct leaf *l)
+{
+        kfree(l);
+}
+
+static inline void free_leaf_info(struct leaf_info *li)
+{
+        kfree(li);
+}
+
+static struct tnode* tnode_new(t_key key, int pos, int bits)
+{
+        int nchildren = 1<<bits;
+        int sz = sizeof(struct tnode) + nchildren * sizeof(struct node *);
+        struct tnode *tn = kmalloc(sz,  GFP_KERNEL);
+
+        if(tn)  {
+                memset(tn, 0, sz);
+                NODE_INIT_PARENT(tn, T_TNODE);
+                tn->pos = pos;
+                tn->bits = bits;
+                tn->key = key;
+                tn->full_children = 0;
+                tn->empty_children = 1<<bits;
+        }
+        if(trie_debug > 0) 
+                printk("AT %p s=%u %u\n", tn, (unsigned int) sizeof(struct tnode),
+                       (unsigned int) (sizeof(struct node) * 1<<bits));
+        return tn;
+}
+
+static void tnode_free(struct tnode *tn)
+{
+        if(!tn) {
+                trie_bug("tnode_free\n");
+        }
+        if(IS_LEAF(tn)) {
+                free_leaf((struct leaf *)tn);
+                if(trie_debug > 0 ) 
+                        printk("FL %p \n", tn);
+        }
+        else if(IS_TNODE(tn)) { 
+                kfree(tn);
+                if(trie_debug > 0 ) 
+                        printk("FT %p \n", tn);
+        }
+        else {
+                trie_bug("tnode_free\n");
+        }
+}
+
+/*
+ * 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(struct tnode *tn, struct 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 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 node *n, int wasfull) 
+{
+        struct node *chi;
+        int isfull;
+
+        if(i >=  1<<tn->bits) {
+                printk("bits=%d, i=%d\n", tn->bits, i);
+                trie_bug("tnode_put_child_reorg bits");
+        }
+        write_lock_bh(&fib_lock);
+        chi = tn->child[i];     
+
+        /* 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); 
+
+        tn->child[i] = n;
+        write_unlock_bh(&fib_lock);
+}
+
+static struct node *resize(struct trie *t, struct tnode *tn) 
+{
+        int i;
+
+        if (!tn)
+                return NULL;
+
+        if(trie_debug) 
+                printk("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(tn);
+                return NULL;
+        }
+        /* One child */
+        if (tn->empty_children == tnode_child_length(tn) - 1)
+                for (i = 0; i < tnode_child_length(tn); i++) {
+
+                        write_lock_bh(&fib_lock);
+                        if (tn->child[i] != NULL) {
+
+                                /* compress one level */
+                                struct node *n = tn->child[i];
+                                if(n)
+                                        NODE_INIT_PARENT(n, NODE_TYPE(n));
+
+                                write_unlock_bh(&fib_lock);
+                                tnode_free(tn);
+                                return n;
+                        }
+                        write_unlock_bh(&fib_lock);
+                }
+        /* 
+         * 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);
+
+        while ((tn->full_children > 0 &&
+               50 * (tn->full_children + tnode_child_length(tn) - tn->empty_children) >=
+                                inflate_threshold * tnode_child_length(tn))) {
+
+                tn = inflate(t, tn);
+        }
+
+        check_tnode(tn);
+
+        /*
+         * Halve as long as the number of empty children in this
+         * node is above threshold.
+         */
+        while (tn->bits > 1 &&
+               100 * (tnode_child_length(tn) - tn->empty_children) <
+               halve_threshold * tnode_child_length(tn))
+
+                tn = halve(t, tn);
+  
+        /* Only one child remains */
+
+        if (tn->empty_children == tnode_child_length(tn) - 1)
+                for (i = 0; i < tnode_child_length(tn); i++) {
+                        
+                        write_lock_bh(&fib_lock);
+                        if (tn->child[i] != NULL) {
+                                /* compress one level */
+                                struct node *n = tn->child[i];
+
+                                if(n)
+                                        NODE_INIT_PARENT(n, NODE_TYPE(n));
+
+                                write_unlock_bh(&fib_lock);
+                                tnode_free(tn);
+                                return n;
+                        }
+                        write_unlock_bh(&fib_lock);
+                }
+
+        return (struct node *) tn;
+}
+
+static struct tnode *inflate(struct trie *t, struct tnode *tn)
+{
+        struct tnode *inode;
+        struct tnode *oldtnode = tn;
+        int olen = tnode_child_length(tn);
+        int i;
+
+        if(trie_debug) 
+                printk("In inflate\n");
+
+        tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits + 1);
+
+        if (!tn)
+                trie_bug("tnode_new failed");
+
+        for(i = 0; i < olen; i++) {
+                struct node *node = tnode_get_child(oldtnode, i);
+      
+                /* 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, tn->pos + tn->bits - 1,
+                                             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, inode->child[0]);
+                        put_child(t, tn, 2*i+1, inode->child[1]);
+
+                        tnode_free(inode);
+                }
+
+                        /* An internal node with more than two children */
+                else {
+                        struct tnode *left, *right;
+                        int size, j;
+
+                        /* 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)
+                         */
+
+                        t_key m = TKEY_GET_MASK(inode->pos, 1);
+ 
+                        /* Use the old key, but set the new significant 
+                         *   bit to zero. 
+                         */
+                        left = tnode_new(inode->key&(~m), inode->pos + 1,
+                                         inode->bits - 1);
+
+                        if(!left) 
+                                trie_bug("tnode_new failed");
+                        
+                        
+                        /* Use the old key, but set the new significant 
+                         * bit to one. 
+                         */
+                        right = tnode_new(inode->key|m, inode->pos + 1,
+                                          inode->bits - 1);
+
+                        if(!right) 
+                                trie_bug("tnode_new failed");
+                        
+                        size = tnode_child_length(left);
+                        for(j = 0; j < size; j++) {
+                                put_child(t, left, j, inode->child[j]);
+                                put_child(t, right, j, 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(inode);
+                }
+        }
+        tnode_free(oldtnode);
+        return tn;
+}
+
+static struct tnode *halve(struct trie *t, struct tnode *tn)
+{
+        struct tnode *oldtnode = tn;
+        struct node *left, *right;
+        int i;
+        int olen = tnode_child_length(tn);
+
+        if(trie_debug) printk("In halve\n");
+  
+        tn=tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits - 1);
+
+        if(!tn) 
+                trie_bug("tnode_new failed");
+
+        for(i = 0; i < olen; i += 2) {
+                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);
+                } else if (right == NULL)
+                        put_child(t, tn, i/2, left);
+     
+                /* Two nonempty children */
+                else {
+                        struct tnode *newBinNode =
+                                tnode_new(left->key, tn->pos + tn->bits, 1);
+
+                        if(!newBinNode) 
+                                trie_bug("tnode_new failed");
+
+                        put_child(t, newBinNode, 0, left);
+                        put_child(t, newBinNode, 1, right);
+                        put_child(t, tn, i/2, resize(t, newBinNode));
+                }
+        }
+        tnode_free(oldtnode);
+        return tn;
+}
+
+static void *trie_init(struct trie *t)
+{
+        if(t) {
+                t->size = 0;
+                t->trie = NULL;
+                t->revision = 0;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+                memset(&t->stats, 0, sizeof(struct trie_use_stats));
+#endif
+        }
+        return t;
+}
+
+static struct leaf_info *find_leaf_info(struct hlist_head *head, int plen)
+{
+        struct hlist_node *node;
+        struct leaf_info *li;
+
+        hlist_for_each_entry(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 list_head *fa_head=NULL;
+        struct leaf_info *li = find_leaf_info(&l->list, plen);
+        
+        if(li) 
+                fa_head = &li->falh;
+        
+        return fa_head;
+}
+
+static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
+{
+        struct leaf_info *li=NULL, *last=NULL;
+        struct hlist_node *node, *tmp;
+
+        write_lock_bh(&fib_lock);
+        
+        if(hlist_empty(head))
+                hlist_add_head(&new->hlist, head);
+        else {
+                hlist_for_each_entry_safe(li, node, tmp, head, hlist) {
+                        
+                        if (new->plen > li->plen) 
+                                break;
+                        
+                        last = li;
+                }
+                if(last) 
+                        hlist_add_after(&last->hlist, &new->hlist);
+                else 
+                        hlist_add_before(&new->hlist, &li->hlist);
+        }
+        write_unlock_bh(&fib_lock);
+}
+
+static struct leaf *
+fib_find_node(struct trie *t, u32 key)
+{
+        int pos;
+        struct tnode *tn;
+        struct node *n;
+
+        pos = 0;
+        n=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(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)) {
+                struct leaf *l = (struct leaf *) n;
+                return l;
+        }
+        return NULL;
+}
+
+static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
+{
+        int i = 0;
+        int wasfull;
+        t_key cindex, key;
+        struct tnode *tp = NULL;
+
+        if(!tn) 
+                BUG();
+        
+        key = tn->key;
+        i = 0;
+
+        while (tn != NULL && NODE_PARENT(tn) != NULL) {
+
+                if( i > 10 ) {
+                        printk("Rebalance tn=%p \n", tn);
+                        if(tn)          printk("tn->parent=%p \n", NODE_PARENT(tn));
+                        
+                        printk("Rebalance tp=%p \n", tp);
+                        if(tp)          printk("tp->parent=%p \n", NODE_PARENT(tp));
+                }
+
+                if( i > 12 ) BUG();
+                i++;
+
+                tp = NODE_PARENT(tn);
+                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 node*)tn, wasfull);
+                
+                if(!NODE_PARENT(tn))
+                        break;
+
+                tn = NODE_PARENT(tn);
+        }
+        /* Handle last (top) tnode */
+        if (IS_TNODE(tn)) 
+                tn = (struct tnode*) resize(t, (struct tnode *)tn);
+
+        return (struct node*) tn;
+}
+
+static struct list_head *
+fib_insert_node(struct trie *t, u32 key, int plen)
+{
+        int pos, newpos;
+        struct tnode *tp = NULL, *tn = NULL;
+        struct node *n;
+        struct leaf *l;
+        int missbit;
+        struct list_head *fa_head=NULL;
+        struct leaf_info *li;
+        t_key cindex;
+
+        pos = 0;
+        n=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));
+
+                        if(n && NODE_PARENT(n) != tn) {
+                                printk("BUG tn=%p, n->parent=%p\n", tn, NODE_PARENT(n));
+                                BUG();
+                        }
+                }
+                else
+                        break;
+        }
+
+        /*
+         * n  ----> NULL, LEAF or TNODE
+         *
+         * tp is n's (parent) ----> NULL or TNODE  
+         */
+
+        if(tp && IS_LEAF(tp))
+                BUG();
+
+        t->revision++;
+
+        /* Case 1: n is a leaf. Compare prefixes */
+
+        if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key)) { 
+                struct leaf *l = ( struct leaf *)  n;
+                
+                li = leaf_info_new(plen);
+                
+                if(! li) 
+                        BUG();
+
+                fa_head = &li->falh;
+                insert_leaf_info(&l->list, li);
+                goto done;
+        }
+        t->size++;
+        l = leaf_new();
+
+        if(! l) 
+                BUG();
+
+        l->key = key;
+        li = leaf_info_new(plen);
+
+        if(! li) 
+                BUG();
+
+        fa_head = &li->falh;
+        insert_leaf_info(&l->list, li);
+
+        /* Case 2: n is NULL, and will just insert a new leaf */
+        if (t->trie && n == NULL) {
+
+                NODE_SET_PARENT(l, tp);
+                
+                if (!tp) 
+                        BUG();
+
+                else {
+                        cindex = tkey_extract_bits(key, tp->pos, tp->bits);
+                        put_child(t, (struct tnode *)tp, cindex, (struct node *)l);
+                }
+        }
+        /* Case 3: n is a LEAF or a TNODE and the key doesn't match. */
+        else {
+                /* 
+                 *  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) 
+                        trie_bug("tnode_pfx_new failed");
+
+                NODE_SET_PARENT(tn, tp);
+
+                missbit=tkey_extract_bits(key, newpos, 1);
+                put_child(t, tn, missbit, (struct 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 node *)tn);
+                }
+                else { 
+                        t->trie = (struct node*) tn; /* First tnode */
+                        tp = tn;
+                }
+        }
+        if(tp && tp->pos+tp->bits > 32) {
+                printk("ERROR tp=%p pos=%d, bits=%d, key=%0x plen=%d\n", 
+                       tp, tp->pos, tp->bits, key, plen);
+        }
+        /* Rebalance the trie */
+        t->trie = trie_rebalance(t, tp);
+done:;
+        return fa_head;
+}
+
+static int
+fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
+               struct nlmsghdr *nlhdr, struct netlink_skb_parms *req)
+{
+        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 = r->rtm_dst_len;
+        int type = r->rtm_type;
+        u8 tos = r->rtm_tos;
+        u32 key, mask;
+        int err;
+        struct leaf *l;
+
+        if (plen > 32)
+                return -EINVAL;
+
+        key = 0;
+        if (rta->rta_dst) 
+                memcpy(&key, rta->rta_dst, 4);
+
+        key = ntohl(key);
+
+        if(trie_debug)
+                printk("Insert table=%d %08x/%d\n", tb->tb_id, key, plen);
+
+        mask =  ntohl( inet_make_mask(plen) );
+
+        if(key & ~mask)
+                return -EINVAL;
+
+        key = key & mask;
+
+        if  ((fi = fib_create_info(r, rta, nlhdr, &err)) == NULL)
+                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_info->fib_priority == fi->fib_priority) {
+                struct fib_alias *fa_orig;
+
+                err = -EEXIST;
+                if (nlhdr->nlmsg_flags & NLM_F_EXCL)
+                        goto out;
+
+                if (nlhdr->nlmsg_flags & NLM_F_REPLACE) {
+                        struct fib_info *fi_drop;
+                        u8 state;
+
+                        write_lock_bh(&fib_lock);
+
+                        fi_drop = fa->fa_info;
+                        fa->fa_info = fi;
+                        fa->fa_type = type;
+                        fa->fa_scope = r->rtm_scope;
+                        state = fa->fa_state;
+                        fa->fa_state &= ~FA_S_ACCESSED;
+
+                        write_unlock_bh(&fib_lock);
+
+                        fib_release_info(fi_drop);
+                        if (state & FA_S_ACCESSED)
+                          rt_cache_flush(-1);
+
+                            goto succeeded;
+                }
+                /* Error if we find a perfect match which
+                 * uses the same scope, type, and nexthop
+                 * information.
+                 */
+                fa_orig = fa;
+                list_for_each_entry(fa, fa_orig->fa_list.prev, fa_list) {
+                        if (fa->fa_tos != tos)
+                                break;
+                        if (fa->fa_info->fib_priority != fi->fib_priority)
+                                break;
+                        if (fa->fa_type == type &&
+                            fa->fa_scope == r->rtm_scope &&
+                            fa->fa_info == fi) {
+                                goto out;
+                        }
+                }
+                if (!(nlhdr->nlmsg_flags & NLM_F_APPEND))
+                        fa = fa_orig;
+        }
+        err = -ENOENT;
+        if (!(nlhdr->nlmsg_flags&NLM_F_CREATE))
+                goto out;
+
+        err = -ENOBUFS;
+        new_fa = kmem_cache_alloc(fn_alias_kmem, SLAB_KERNEL);
+        if (new_fa == NULL)
+                goto out;
+
+        new_fa->fa_info = fi;
+        new_fa->fa_tos = tos;
+        new_fa->fa_type = type;
+        new_fa->fa_scope = r->rtm_scope;
+        new_fa->fa_state = 0;
+#if 0
+        new_fa->dst  = NULL;
+#endif
+        /*
+         * Insert new entry to the list.
+         */
+
+        if(!fa_head)
+                fa_head = fib_insert_node(t, key, plen);
+
+        write_lock_bh(&fib_lock);
+
+        list_add_tail(&new_fa->fa_list,
+                 (fa ? &fa->fa_list : fa_head));
+
+        write_unlock_bh(&fib_lock);
+
+        rt_cache_flush(-1);
+        rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id, nlhdr, req);
+succeeded:
+        return 0;
+out:
+        fib_release_info(fi);
+err:;   
+        return err;
+}
+
+static inline int check_leaf(struct trie *t, struct leaf *l,  t_key key, int *plen, const struct flowi *flp, 
+                             struct fib_result *res, int *err)
+{
+        int i;
+        t_key mask;
+        struct leaf_info *li;
+        struct hlist_head *hhead = &l->list;
+        struct hlist_node *node;
+        
+        hlist_for_each_entry(li, node, hhead, hlist) {
+
+                i = li->plen;
+                mask = ntohl(inet_make_mask(i));
+                if (l->key != (key & mask)) 
+                        continue;
+
+                if (((*err) = fib_semantic_match(&li->falh, flp, res, l->key, mask, i)) == 0) {
+                        *plen = i;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+                        t->stats.semantic_match_passed++;
+#endif
+                        return 1;
+                }
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+                t->stats.semantic_match_miss++;
+#endif
+        }
+        return 0;
+}
+
+static int
+fn_trie_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
+{
+        struct trie *t = (struct trie *) tb->tb_data;
+        int plen, ret = 0;
+        struct node *n;
+        struct tnode *pn;
+        int pos, bits;
+        t_key key=ntohl(flp->fl4_dst);
+        int chopped_off;
+        t_key cindex = 0;
+        int current_prefix_length = KEYLENGTH;
+        n = t->trie;
+
+        read_lock(&fib_lock);
+        if(!n)
+                goto failed;
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+        t->stats.gets++;
+#endif
+
+        /* Just a leaf? */
+        if (IS_LEAF(n)) {
+                if( check_leaf(t, (struct leaf *)n, key, &plen, flp, res, &ret) )
+                        goto found;
+                goto failed;
+        }
+        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(pn, cindex);
+
+                if (n == NULL) {
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+                        t->stats.null_node_hit++;
+#endif
+                        goto backtrace;
+                }
+
+                if (IS_TNODE(n)) {
+#define HL_OPTIMIZE
+#ifdef HL_OPTIMIZE
+                        struct tnode *cn = (struct tnode *)n;
+                        t_key node_prefix, key_prefix, pref_mismatch;
+                        int mp;
+
+                        /*
+                         * 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) != 0 ||
+                                    !(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.
+                         */
+
+                        node_prefix = MASK_PFX(cn->key, cn->pos);
+                        key_prefix =  MASK_PFX(key, cn->pos);
+                        pref_mismatch = key_prefix^node_prefix;
+                        mp = 0;
+
+                        /* In short: If skipped bits in this node do not match the search 
+                         * key, enter the "prefix matching" state.directly.
+                         */
+                        if (pref_mismatch) {
+                                while (!(pref_mismatch & (1<<(KEYLENGTH-1)))) {
+                                        mp++;
+                                        pref_mismatch = pref_mismatch <<1;
+                                }
+                                key_prefix = tkey_extract_bits(cn->key, mp, cn->pos-mp);
+                                
+                                if (key_prefix != 0)
+                                        goto backtrace;
+
+                                if (current_prefix_length >= cn->pos)
+                                        current_prefix_length=mp;
+                       }
+#endif
+                       pn = (struct tnode *)n; /* Descend */
+                       chopped_off = 0;
+                       continue;
+                } 
+                if (IS_LEAF(n)) {       
+                        if( check_leaf(t, (struct leaf *)n, key, &plen, flp, res, &ret))
+                                goto found;
+               }
+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 {
+                        if( NODE_PARENT(pn) == NULL)
+                                goto failed;
+                        
+                        /* Get Child's index */
+                        cindex = tkey_extract_bits(pn->key, NODE_PARENT(pn)->pos, NODE_PARENT(pn)->bits);
+                        pn = NODE_PARENT(pn);
+                        chopped_off = 0;
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+                        t->stats.backtrack++;
+#endif
+                        goto backtrace;
+                } 
+        }
+failed:
+        ret =  1;
+found:
+        read_unlock(&fib_lock);
+        return ret;
+}
+
+static int trie_leaf_remove(struct trie *t, t_key key)
+{
+        t_key cindex;
+        struct tnode *tp = NULL;
+        struct node *n = t->trie;
+        struct leaf *l;
+
+        if(trie_debug) 
+                printk("entering trie_leaf_remove(%p)\n", n);
+
+        /* Note that in the case skipped bits, those bits are *not* checked!
+         * When we finish this, we will have NULL or a T_LEAF, and the 
+         * T_LEAF may or may not match our key.
+         */
+
+        while (n != NULL && IS_TNODE(n)) {
+                struct tnode *tn = (struct tnode *) n;
+                check_tnode(tn);
+                n = tnode_get_child(tn ,tkey_extract_bits(key, tn->pos, tn->bits));
+
+                        if(n && NODE_PARENT(n) != tn) {
+                                printk("BUG tn=%p, n->parent=%p\n", tn, NODE_PARENT(n));
+                                BUG();
+                        }
+        }
+        l = (struct leaf *) n;
+
+        if(!n || !tkey_equals(l->key, key)) 
+                return 0;
+    
+        /* 
+         * Key found. 
+         * Remove the leaf and rebalance the tree 
+         */
+
+        t->revision++;
+        t->size--;
+
+        tp = NODE_PARENT(n);
+        tnode_free((struct tnode *) n);
+
+        if(tp) {
+                cindex = tkey_extract_bits(key, tp->pos, tp->bits);
+                put_child(t, (struct tnode *)tp, cindex, NULL);
+                t->trie = trie_rebalance(t, tp);
+        }
+        else
+                t->trie = NULL;
+
+        return 1;
+}
+
+static int
+fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
+               struct nlmsghdr *nlhdr, struct netlink_skb_parms *req)
+{
+        struct trie *t = (struct trie *) tb->tb_data;
+        u32 key, mask;
+        int plen = r->rtm_dst_len;
+        u8 tos = r->rtm_tos;
+        struct fib_alias *fa, *fa_to_delete;
+        struct list_head *fa_head;
+        struct leaf *l;
+
+        if (plen > 32) 
+                return -EINVAL;
+
+        key = 0;
+        if (rta->rta_dst) 
+                memcpy(&key, rta->rta_dst, 4);
+
+        key = ntohl(key);
+        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;
+
+        if (trie_debug)
+                printk("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
+
+        fa_to_delete = NULL;
+        fa_head = fa->fa_list.prev;
+        list_for_each_entry(fa, fa_head, fa_list) {
+                struct fib_info *fi = fa->fa_info;
+
+                if (fa->fa_tos != tos)
+                        break;
+
+                if ((!r->rtm_type ||
+                     fa->fa_type == r->rtm_type) &&
+                    (r->rtm_scope == RT_SCOPE_NOWHERE ||
+                     fa->fa_scope == r->rtm_scope) &&
+                    (!r->rtm_protocol ||
+                     fi->fib_protocol == r->rtm_protocol) &&
+                    fib_nh_match(r, nlhdr, rta, fi) == 0) {
+                        fa_to_delete = fa;
+                        break;
+                }
+        }
+
+        if (fa_to_delete) {
+                int kill_li = 0;
+                struct leaf_info *li;
+
+                fa = fa_to_delete;
+                rtmsg_fib(RTM_DELROUTE, htonl(key), fa, plen, tb->tb_id, nlhdr, req);
+
+                l = fib_find_node(t, key);
+                li = find_leaf_info(&l->list, plen);
+
+                write_lock_bh(&fib_lock);
+
+                list_del(&fa->fa_list);
+
+                if(list_empty(fa_head)) {
+                        hlist_del(&li->hlist);
+                        kill_li = 1;
+                }
+                write_unlock_bh(&fib_lock);
+                
+                if(kill_li)
+                        free_leaf_info(li);
+
+                if(hlist_empty(&l->list))
+                        trie_leaf_remove(t, key);
+
+                if (fa->fa_state & FA_S_ACCESSED)
+                        rt_cache_flush(-1);
+
+                fn_free_alias(fa);
+                return 0;
+        }
+        return -ESRCH;
+}
+
+static int trie_flush_list(struct trie *t, 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)) {
+
+                        write_lock_bh(&fib_lock);       
+                        list_del(&fa->fa_list);
+                        write_unlock_bh(&fib_lock); 
+
+                        fn_free_alias(fa);
+                        found++;
+                }
+        }
+        return found;
+}
+
+static int trie_flush_leaf(struct trie *t, 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(t, &li->falh);
+
+                if (list_empty(&li->falh)) {
+
+                        write_lock_bh(&fib_lock); 
+                        hlist_del(&li->hlist);
+                        write_unlock_bh(&fib_lock); 
+
+                        free_leaf_info(li);
+                }
+        }
+        return found;
+}
+
+static struct leaf *nextleaf(struct trie *t, struct leaf *thisleaf)
+{
+        struct node *c = (struct node *) thisleaf;
+        struct tnode *p;
+        int idx;
+
+        if(c == NULL) {
+                if(t->trie == NULL)
+                        return NULL;
+
+                if (IS_LEAF(t->trie))          /* trie w. just a leaf */
+                        return (struct leaf *) t->trie;
+
+                p = (struct tnode*) t->trie;  /* Start */
+        }
+        else 
+                p = (struct tnode *) NODE_PARENT(c);
+        while (p) {
+                int pos, last;
+
+                /*  Find the next child of the parent */
+                if(c)
+                        pos  = 1 + tkey_extract_bits(c->key, p->pos, p->bits);
+                else 
+                        pos = 0;
+
+                last = 1 << p->bits;
+                for(idx = pos; idx < last ; idx++) {
+                        if( p->child[idx]) {
+
+                                /* Decend if tnode */
+
+                                while (IS_TNODE(p->child[idx])) {
+                                        p = (struct tnode*) p->child[idx];
+                                        idx = 0;
+                                        
+                                        /* Rightmost non-NULL branch */
+                                        if( p && IS_TNODE(p) )
+                                                while ( p->child[idx] == NULL && idx < (1 << p->bits) ) idx++;
+
+                                        /* Done with this tnode? */
+                                        if( idx >= (1 << p->bits) || p->child[idx] == NULL ) 
+                                                goto up;
+                                }
+                                return (struct leaf*) p->child[idx];
+                        }
+                }
+up:
+                /* No more children go up one step  */
+                c = (struct node*) p;
+                p = (struct tnode *) NODE_PARENT(p);
+        }
+        return NULL; /* Ready. Root of trie */
+}
+
+static int fn_trie_flush(struct fib_table *tb)
+{
+        struct trie *t = (struct trie *) tb->tb_data;
+        struct leaf *ll = NULL, *l = NULL;
+        int found = 0, h;
+
+        t->revision++;
+
+        for (h=0; (l = nextleaf(t, l)) != NULL; h++) {
+                found += trie_flush_leaf(t, l);
+
+                if (ll && hlist_empty(&ll->list))
+                        trie_leaf_remove(t, ll->key);
+                ll = l;
+        }
+
+        if (ll && hlist_empty(&ll->list))
+                trie_leaf_remove(t, ll->key);
+
+        if(trie_debug) 
+                printk("trie_flush found=%d\n", found);
+        return found;
+}
+
+static int trie_last_dflt=-1;
+
+static void
+fn_trie_select_default(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
+{
+        struct trie *t = (struct trie *) tb->tb_data;
+        int order, last_idx;
+        struct fib_info *fi = NULL;
+        struct fib_info *last_resort;
+        struct fib_alias *fa = NULL;
+        struct list_head *fa_head;
+        struct leaf *l;
+
+        last_idx = -1;
+        last_resort = NULL;
+        order = -1;
+
+        read_lock(&fib_lock);
+        
+        l = fib_find_node(t, 0);
+        if(!l) 
+                goto out;
+
+        fa_head = get_fa_head(l, 0);
+        if(!fa_head)
+                goto out;
+
+        if (list_empty(fa_head)) 
+                goto out;
+
+        list_for_each_entry(fa, fa_head, fa_list) {
+                struct fib_info *next_fi = fa->fa_info;
+                
+                if (fa->fa_scope != res->scope ||
+                    fa->fa_type != RTN_UNICAST)
+                        continue;
+                
+                if (next_fi->fib_priority > res->fi->fib_priority)
+                        break;
+                if (!next_fi->fib_nh[0].nh_gw ||
+                    next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
+                        continue;
+                fa->fa_state |= FA_S_ACCESSED;
+                
+                if (fi == NULL) {
+                        if (next_fi != res->fi)
+                                break;
+                } else if (!fib_detect_death(fi, order, &last_resort,
+                                             &last_idx, &trie_last_dflt)) {
+                        if (res->fi)
+                                fib_info_put(res->fi);
+                        res->fi = fi;
+                        atomic_inc(&fi->fib_clntref);
+                        trie_last_dflt = order;
+                        goto out;
+                }
+                fi = next_fi;
+                order++;
+        }
+        if (order <= 0 || fi == NULL) {
+                trie_last_dflt = -1;
+                goto out;
+        }
+
+        if (!fib_detect_death(fi, order, &last_resort, &last_idx, &trie_last_dflt)) {
+                if (res->fi)
+                        fib_info_put(res->fi);
+                res->fi = fi;
+                atomic_inc(&fi->fib_clntref);
+                trie_last_dflt = order;
+                goto out;
+        }
+        if (last_idx >= 0) {
+                if (res->fi)
+                        fib_info_put(res->fi);
+                res->fi = last_resort;
+                if (last_resort)
+                        atomic_inc(&last_resort->fib_clntref);
+        }
+        trie_last_dflt = last_idx;
+ out:;
+        read_unlock(&fib_lock); 
+}
+
+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;
+
+        u32 xkey=htonl(key);
+
+        s_i=cb->args[3];
+        i = 0;
+
+        list_for_each_entry(fa, fah, fa_list) {
+                if (i < s_i) {
+                        i++;
+                        continue;
+                }
+                if (fa->fa_info->fib_nh == NULL) {
+                        printk("Trie error _fib_nh=NULL in fa[%d] k=%08x plen=%d\n", i, key, plen);
+                        i++;
+                        continue;
+                }
+                if (fa->fa_info == NULL) {
+                        printk("Trie error fa_info=NULL in fa[%d] k=%08x plen=%d\n", i, key, plen);
+                        i++;
+                        continue;
+                }
+
+                if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
+                                  cb->nlh->nlmsg_seq,
+                                  RTM_NEWROUTE,
+                                  tb->tb_id,
+                                  fa->fa_type,
+                                  fa->fa_scope,
+                                  &xkey,
+                                  plen,
+                                  fa->fa_tos,
+                                  fa->fa_info) < 0) {
+                        cb->args[3] = i;
+                        return -1;
+                        }
+                i++;
+        }
+        cb->args[3]=i;
+        return skb->len;
+}
+
+static int fn_trie_dump_plen(struct trie *t, int plen, struct fib_table *tb, struct sk_buff *skb, 
+                             struct netlink_callback *cb)
+{
+        int h, s_h;
+        struct list_head *fa_head;
+        struct leaf *l = NULL;
+        s_h=cb->args[2];
+
+        for (h=0; (l = nextleaf(t, l)) != NULL; h++) {
+
+                if (h < s_h)
+                        continue;
+                if (h > s_h)
+                        memset(&cb->args[3], 0,
+                               sizeof(cb->args) - 3*sizeof(cb->args[0]));
+
+                fa_head = get_fa_head(l, plen);
+                
+                if(!fa_head)
+                        continue;
+
+                if(list_empty(fa_head))
+                        continue;
+
+                if (fn_trie_dump_fa(l->key, plen, fa_head, tb, skb, cb)<0) {
+                        cb->args[2]=h;
+                        return -1;
+                }
+        }
+        cb->args[2]=h;
+        return skb->len;
+}
+
+static int fn_trie_dump(struct fib_table *tb, struct sk_buff *skb, struct netlink_callback *cb)
+{
+        int m, s_m;
+        struct trie *t = (struct trie *) tb->tb_data;
+
+        s_m = cb->args[1];
+
+        read_lock(&fib_lock);
+        for (m=0; m<=32; m++) {
+
+                if (m < s_m)
+                        continue;
+                if (m > s_m)
+                        memset(&cb->args[2], 0,
+                               sizeof(cb->args) - 2*sizeof(cb->args[0]));
+
+                if (fn_trie_dump_plen(t, 32-m, tb, skb, cb)<0) {
+                        cb->args[1] = m;
+                        goto out;
+                }
+        }
+        read_unlock(&fib_lock);
+        cb->args[1] = m;
+        return skb->len;
+ out:
+        read_unlock(&fib_lock);
+        return -1;
+}
+
+/* Fix more generic FIB names for init later */
+
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+struct fib_table * fib_hash_init(int id)
+#else
+struct fib_table * __init fib_hash_init(int id)
+#endif
+{
+        struct fib_table *tb;
+        struct trie *t;
+
+        if (fn_alias_kmem == NULL)
+                fn_alias_kmem = kmem_cache_create("ip_fib_alias",
+                                                  sizeof(struct fib_alias),
+                                                  0, SLAB_HWCACHE_ALIGN,
+                                                  NULL, NULL);
+
+        tb = kmalloc(sizeof(struct fib_table) + sizeof(struct trie),
+                     GFP_KERNEL);
+        if (tb == NULL)
+                return NULL;
+
+        tb->tb_id = id;
+        tb->tb_lookup = fn_trie_lookup;
+        tb->tb_insert = fn_trie_insert;
+        tb->tb_delete = fn_trie_delete;
+        tb->tb_flush = fn_trie_flush;
+        tb->tb_select_default = fn_trie_select_default;
+        tb->tb_dump = fn_trie_dump;
+        memset(tb->tb_data, 0, sizeof(struct trie));
+
+        t = (struct trie *) tb->tb_data;
+
+        trie_init(t);
+
+        if (id == RT_TABLE_LOCAL) 
+                trie_local=t;
+          else if (id == RT_TABLE_MAIN) 
+                trie_main=t;
+
+        if (id == RT_TABLE_LOCAL)
+                printk("IPv4 FIB: Using LC-trie version %s\n", VERSION);
+
+        return tb;
+}
+
+/* Trie dump functions */
+
+static void putspace_seq(struct seq_file *seq, int n)
+{
+        while (n--) seq_printf(seq, " ");
+}
+
+static void printbin_seq(struct seq_file *seq, unsigned int v, int bits)
+{
+        while (bits--)
+                seq_printf(seq, "%s", (v & (1<<bits))?"1":"0");
+}
+
+static void printnode_seq(struct seq_file *seq, int indent, struct node *n, 
+                   int pend, int cindex, int bits)
+{
+        putspace_seq(seq, indent);
+        if (IS_LEAF(n))
+                seq_printf(seq, "|");
+        else
+                seq_printf(seq, "+");
+        if (bits) {
+                seq_printf(seq, "%d/", cindex);
+                printbin_seq(seq, cindex, bits);
+                seq_printf(seq, ": ");
+        }
+        else
+                seq_printf(seq, "<root>: ");
+        seq_printf(seq, "%s:%p ", IS_LEAF(n)?"Leaf":"Internal node", n);
+
+        if (IS_LEAF(n))
+                seq_printf(seq, "key=%d.%d.%d.%d\n", 
+                           n->key >> 24, (n->key >> 16) % 256, (n->key >> 8) % 256, n->key % 256);
+        else {
+                int plen=((struct tnode *)n)->pos;
+                t_key prf=MASK_PFX(n->key, plen);
+                seq_printf(seq, "key=%d.%d.%d.%d/%d\n", 
+                           prf >> 24, (prf >> 16) % 256, (prf >> 8) % 256, prf % 256, plen);
+        }
+        if (IS_LEAF(n)) {
+                struct leaf *l=(struct leaf *)n;
+                struct fib_alias *fa;
+                int i;
+                for (i=32; i>=0; i--)
+                  if(find_leaf_info(&l->list, i)) {
+                        
+                                struct list_head *fa_head = get_fa_head(l, i);
+                                
+                                if(!fa_head)
+                                        continue;
+
+                                if(list_empty(fa_head))
+                                        continue;
+
+                                putspace_seq(seq, indent+2);
+                                seq_printf(seq, "{/%d...dumping}\n", i);
+
+
+                                list_for_each_entry(fa, fa_head, fa_list) {
+                                        putspace_seq(seq, indent+2);
+                                        if (fa->fa_info->fib_nh == NULL) {
+                                                seq_printf(seq, "Error _fib_nh=NULL\n");
+                                                continue;
+                                        }
+                                        if (fa->fa_info == NULL) {
+                                                seq_printf(seq, "Error fa_info=NULL\n");
+                                                continue;
+                                        }
+
+                                        seq_printf(seq, "{type=%d scope=%d TOS=%d}\n",
+                                              fa->fa_type,
+                                              fa->fa_scope,
+                                              fa->fa_tos);
+                                }
+                        }
+        }
+        else if (IS_TNODE(n)) {
+                struct tnode *tn=(struct tnode *)n;
+                putspace_seq(seq, indent); seq_printf(seq, "|    ");
+                seq_printf(seq, "{key prefix=%08x/", tn->key&TKEY_GET_MASK(0, tn->pos));
+                printbin_seq(seq, tkey_extract_bits(tn->key, 0, tn->pos), tn->pos);
+                seq_printf(seq, "}\n");
+                putspace_seq(seq, indent); seq_printf(seq, "|    ");
+                seq_printf(seq, "{pos=%d", tn->pos);
+                seq_printf(seq, " (skip=%d bits)", tn->pos - pend);
+                seq_printf(seq, " bits=%d (%u children)}\n", tn->bits, (1 << tn->bits));
+                putspace_seq(seq, indent); seq_printf(seq, "|    ");
+                seq_printf(seq, "{empty=%d full=%d}\n", tn->empty_children, tn->full_children);
+        }
+}
+
+static void trie_dump_seq(struct seq_file *seq, struct trie *t)
+{
+        struct node *n=t->trie;
+        int cindex=0;
+        int indent=1;
+        int pend=0;
+        int depth = 0;
+
+        read_lock(&fib_lock);
+
+        seq_printf(seq, "------ trie_dump of t=%p ------\n", t);
+        if (n) {
+                printnode_seq(seq, indent, n, pend, cindex, 0);
+                if (IS_TNODE(n)) {
+                        struct tnode *tn=(struct tnode *)n;
+                        pend = tn->pos+tn->bits;
+                        putspace_seq(seq, indent); seq_printf(seq, "\\--\n");
+                        indent += 3;
+                        depth++;
+
+                        while (tn && cindex < (1 << tn->bits)) {
+                                if (tn->child[cindex]) {
+                                        
+                                        /* Got a child */
+                                        
+                                        printnode_seq(seq, indent, tn->child[cindex], pend, cindex, tn->bits);
+                                        if (IS_LEAF(tn->child[cindex])) { 
+                                                cindex++;
+                                                
+                                        }
+                                        else {
+                                                /* 
+                                                 * New tnode. Decend one level 
+                                                 */
+                                                
+                                                depth++;
+                                                n=tn->child[cindex];
+                                                tn=(struct tnode *)n;
+                                                pend=tn->pos+tn->bits;
+                                                putspace_seq(seq, indent); seq_printf(seq, "\\--\n");
+                                                indent+=3;
+                                                cindex=0;
+                                        }
+                                }
+                                else 
+                                        cindex++;
+
+                                /*
+                                 * Test if we are done 
+                                 */
+                                
+                                while (cindex >= (1 << tn->bits)) {
+
+                                        /*
+                                         * Move upwards and test for root
+                                         * pop off all traversed  nodes
+                                         */
+                                        
+                                        if (NODE_PARENT(tn) == NULL) {
+                                                tn = NULL;
+                                                n = NULL;
+                                                break;
+                                        }
+                                        else {
+                                                cindex = tkey_extract_bits(tn->key, NODE_PARENT(tn)->pos, NODE_PARENT(tn)->bits);
+                                                tn = NODE_PARENT(tn);
+                                                cindex++;
+                                                n=(struct node *)tn;
+                                                pend=tn->pos+tn->bits;
+                                                indent-=3;
+                                                depth--;
+                                        }
+                                }
+                        }
+                }
+                else n = NULL;
+        }
+        else seq_printf(seq, "------ trie is empty\n");
+
+        read_unlock(&fib_lock);
+}
+
+static struct trie_stat *trie_stat_new(void)
+{
+        struct trie_stat *s = kmalloc(sizeof(struct trie_stat), GFP_KERNEL);
+        int i;
+        
+        if(s) {
+                s->totdepth = 0;
+                s->maxdepth = 0;
+                s->tnodes = 0;
+                s->leaves = 0;
+                s->nullpointers = 0;
+                
+                for(i=0; i< MAX_CHILDS; i++)
+                        s->nodesizes[i] = 0;
+        }
+        return s;
+}    
+
+static struct trie_stat *trie_collect_stats(struct trie *t)
+{
+        struct node *n=t->trie;
+        struct trie_stat *s = trie_stat_new();
+        int cindex = 0;
+        int indent = 1;
+        int pend = 0;
+        int depth = 0;
+
+        read_lock(&fib_lock);           
+
+        if (s) {
+                if (n) {
+                        if (IS_TNODE(n)) {
+                                struct tnode *tn = (struct tnode *)n;
+                                pend=tn->pos+tn->bits;
+                                indent += 3;
+                                s->nodesizes[tn->bits]++;
+                                depth++;
+
+                                while (tn && cindex < (1 << tn->bits)) {
+                                        if (tn->child[cindex]) {
+                                                /* Got a child */
+                                        
+                                                if (IS_LEAF(tn->child[cindex])) { 
+                                                        cindex++;
+                                                
+                                                        /* stats */
+                                                        if (depth > s->maxdepth)
+                                                                s->maxdepth = depth;
+                                                        s->totdepth += depth;
+                                                        s->leaves++;
+                                                }
+                                        
+                                                else {
+                                                        /* 
+                                                         * New tnode. Decend one level 
+                                                         */
+                                                
+                                                        s->tnodes++;
+                                                        s->nodesizes[tn->bits]++;
+                                                        depth++;
+                                                
+                                                        n = tn->child[cindex];
+                                                        tn = (struct tnode *)n;
+                                                        pend = tn->pos+tn->bits;
+
+                                                        indent += 3;
+                                                        cindex = 0;
+                                                }
+                                        }
+                                        else {
+                                                cindex++;
+                                                s->nullpointers++; 
+                                        }
+
+                                        /*
+                                         * Test if we are done 
+                                         */
+                                
+                                        while (cindex >= (1 << tn->bits)) {
+
+                                                /*
+                                                 * Move upwards and test for root
+                                                 * pop off all traversed  nodes
+                                                 */
+
+                                                
+                                                if (NODE_PARENT(tn) == NULL) {
+                                                        tn = NULL;
+                                                        n = NULL;
+                                                        break;
+                                                }
+                                                else {
+                                                        cindex = tkey_extract_bits(tn->key, NODE_PARENT(tn)->pos, NODE_PARENT(tn)->bits);
+                                                        tn = NODE_PARENT(tn);
+                                                        cindex++; 
+                                                        n = (struct node *)tn;
+                                                        pend=tn->pos+tn->bits;
+                                                        indent -= 3;
+                                                        depth--;
+                                                }
+                                        }
+                                }
+                        }
+                        else n = NULL;
+                }
+        }
+
+        read_unlock(&fib_lock);         
+        return s;
+}
+
+#ifdef CONFIG_PROC_FS
+
+static struct fib_alias *fib_triestat_get_first(struct seq_file *seq)
+{
+        return NULL;
+}
+
+static struct fib_alias *fib_triestat_get_next(struct seq_file *seq)
+{
+        return NULL;
+}
+
+static void *fib_triestat_seq_start(struct seq_file *seq, loff_t *pos)
+{
+        void *v = NULL;
+
+        if (ip_fib_main_table)
+                v = *pos ? fib_triestat_get_next(seq) : SEQ_START_TOKEN;
+        return v;
+}
+
+static void *fib_triestat_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        ++*pos;
+        return v == SEQ_START_TOKEN ? fib_triestat_get_first(seq) : fib_triestat_get_next(seq);
+}
+
+static void fib_triestat_seq_stop(struct seq_file *seq, void *v)
+{
+
+}
+
+/* 
+ *      This outputs /proc/net/fib_triestats
+ *
+ *      It always works in backward compatibility mode.
+ *      The format of the file is not supposed to be changed.
+ */
+
+static void collect_and_show(struct trie *t, struct seq_file *seq)
+{
+        int bytes = 0; /* How many bytes are used, a ref is 4 bytes */
+        int i, max, pointers;
+        struct trie_stat *stat;
+        int avdepth;
+
+        stat = trie_collect_stats(t);
+
+        bytes=0;
+        seq_printf(seq, "trie=%p\n", t);
+
+        if (stat) {
+                if (stat->leaves)
+                        avdepth=stat->totdepth*100 / stat->leaves;
+                else
+                        avdepth=0;
+                seq_printf(seq, "Aver depth: %d.%02d\n", avdepth / 100, avdepth % 100 );
+                seq_printf(seq, "Max depth: %4d\n", stat->maxdepth);
+                                
+                seq_printf(seq, "Leaves: %d\n", stat->leaves);
+                bytes += sizeof(struct leaf) * stat->leaves;
+                seq_printf(seq, "Internal nodes: %d\n", stat->tnodes);
+                bytes += sizeof(struct tnode) * stat->tnodes;
+
+                max = MAX_CHILDS-1;
+
+                while (max >= 0 && stat->nodesizes[max] == 0)
+                        max--;
+                pointers = 0;
+
+                for (i = 1; i <= max; i++) 
+                        if (stat->nodesizes[i] != 0) {
+                                seq_printf(seq, "  %d: %d",  i, stat->nodesizes[i]);
+                                pointers += (1<<i) * stat->nodesizes[i];
+                        }
+                seq_printf(seq, "\n");
+                seq_printf(seq, "Pointers: %d\n", pointers);
+                bytes += sizeof(struct node *) * pointers;
+                seq_printf(seq, "Null ptrs: %d\n", stat->nullpointers);
+                seq_printf(seq, "Total size: %d  kB\n", bytes / 1024);
+
+                kfree(stat);
+        }
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+        seq_printf(seq, "Counters:\n---------\n");
+        seq_printf(seq,"gets = %d\n", t->stats.gets);
+        seq_printf(seq,"backtracks = %d\n", t->stats.backtrack);
+        seq_printf(seq,"semantic match passed = %d\n", t->stats.semantic_match_passed);
+        seq_printf(seq,"semantic match miss = %d\n", t->stats.semantic_match_miss);
+        seq_printf(seq,"null node hit= %d\n", t->stats.null_node_hit);
+#ifdef CLEAR_STATS
+        memset(&(t->stats), 0, sizeof(t->stats));
+#endif
+#endif /*  CONFIG_IP_FIB_TRIE_STATS */
+}
+
+static int fib_triestat_seq_show(struct seq_file *seq, void *v)
+{
+        char bf[128];
+    
+        if (v == SEQ_START_TOKEN) {
+                seq_printf(seq, "Basic info: size of leaf: %Zd bytes, size of tnode: %Zd bytes.\n", 
+                           sizeof(struct leaf), sizeof(struct tnode));
+                if (trie_local) 
+                        collect_and_show(trie_local, seq);
+
+                if (trie_main) 
+                        collect_and_show(trie_main, seq);
+        }
+        else {
+                snprintf(bf, sizeof(bf),
+                         "*\t%08X\t%08X", 200, 400);
+                
+                seq_printf(seq, "%-127s\n", bf);
+        }
+        return 0;
+}
+
+static struct seq_operations fib_triestat_seq_ops = {
+        .start  = fib_triestat_seq_start,
+        .next   = fib_triestat_seq_next,
+        .stop   = fib_triestat_seq_stop,
+        .show   = fib_triestat_seq_show,
+};
+
+static int fib_triestat_seq_open(struct inode *inode, struct file *file)
+{
+        struct seq_file *seq;
+        int rc = -ENOMEM;
+
+        rc = seq_open(file, &fib_triestat_seq_ops);
+        if (rc)
+                goto out_kfree;
+
+        seq          = file->private_data;
+out:
+        return rc;
+out_kfree:
+        goto out;
+}
+
+static struct file_operations fib_triestat_seq_fops = {
+        .owner          = THIS_MODULE,
+        .open           = fib_triestat_seq_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = seq_release_private,
+};
+
+int __init fib_stat_proc_init(void)
+{
+        if (!proc_net_fops_create("fib_triestat", S_IRUGO, &fib_triestat_seq_fops))
+                return -ENOMEM;
+        return 0;
+}
+
+void __init fib_stat_proc_exit(void)
+{
+        proc_net_remove("fib_triestat");
+}
+
+static struct fib_alias *fib_trie_get_first(struct seq_file *seq)
+{
+        return NULL;
+}
+
+static struct fib_alias *fib_trie_get_next(struct seq_file *seq)
+{
+        return NULL;
+}
+
+static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
+{
+        void *v = NULL;
+
+        if (ip_fib_main_table)
+                v = *pos ? fib_trie_get_next(seq) : SEQ_START_TOKEN;
+        return v;
+}
+
+static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        ++*pos;
+        return v == SEQ_START_TOKEN ? fib_trie_get_first(seq) : fib_trie_get_next(seq);
+}
+
+static void fib_trie_seq_stop(struct seq_file *seq, void *v)
+{
+
+}
+
+/* 
+ *      This outputs /proc/net/fib_trie.
+ *
+ *      It always works in backward compatibility mode.
+ *      The format of the file is not supposed to be changed.
+ */
+
+static int fib_trie_seq_show(struct seq_file *seq, void *v)
+{
+        char bf[128];
+
+        if (v == SEQ_START_TOKEN) {
+                if (trie_local) 
+                        trie_dump_seq(seq, trie_local);
+
+                if (trie_main) 
+                        trie_dump_seq(seq, trie_main);
+        }
+
+        else {
+                snprintf(bf, sizeof(bf),
+                         "*\t%08X\t%08X", 200, 400);
+                seq_printf(seq, "%-127s\n", bf);
+        }
+
+        return 0;
+}
+
+static 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)
+{
+        struct seq_file *seq;
+        int rc = -ENOMEM;
+
+        rc = seq_open(file, &fib_trie_seq_ops);
+        if (rc)
+                goto out_kfree;
+
+        seq          = file->private_data;
+out:
+        return rc;
+out_kfree:
+        goto out;
+}
+
+static struct file_operations fib_trie_seq_fops = {
+        .owner          = THIS_MODULE,
+        .open           = fib_trie_seq_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = seq_release_private,
+};
+
+int __init fib_proc_init(void)
+{
+        if (!proc_net_fops_create("fib_trie", S_IRUGO, &fib_trie_seq_fops))
+                return -ENOMEM;
+        return 0;
+}
+
+void __init fib_proc_exit(void)
+{
+        proc_net_remove("fib_trie");
+}
+
+#endif /* CONFIG_PROC_FS */