fib_trie.c 60.1 KB
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/*
 *   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.
 */

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#define VERSION "0.325"
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#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) \
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	((struct tnode *)((_node)->_parent & ~NODE_TYPE_MASK))
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#define NODE_SET_PARENT(_node, _ptr) \
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	((_node)->_parent = (((unsigned long)(_ptr)) | \
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                     ((_node)->_parent & NODE_TYPE_MASK)))
#define NODE_INIT_PARENT(_node, _type) \
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	((_node)->_parent = (_type))
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#define NODE_TYPE(_node) \
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	((_node)->_parent & NODE_TYPE_MASK)
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#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;
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	unsigned int resize_node_skipped;
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};
#endif

struct trie_stat {
	unsigned int totdepth;
	unsigned int maxdepth;
	unsigned int tnodes;
	unsigned int leaves;
	unsigned int nullpointers;
	unsigned int nodesizes[MAX_CHILDS];
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};
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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);
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static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err);
static struct tnode *halve(struct trie *t, struct tnode *tn, int *err);
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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();
}

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static inline struct node *tnode_get_child(struct tnode *tn, int i)
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{
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        if (i >= 1<<tn->bits)
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                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 |
  ----------------------------------------------------------------
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    0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
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  _________________________________________________________________
  | 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)
{
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	return a == b;
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}

static inline int tkey_sub_equals(t_key a, int offset, int bits, t_key b)
{
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	if (bits == 0 || offset >= KEYLENGTH)
		return 1;
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        bits = bits > KEYLENGTH ? KEYLENGTH : bits;
        return ((a ^ b) << offset) >> (KEYLENGTH - bits) == 0;
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}
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static inline int tkey_mismatch(t_key a, int offset, t_key b)
{
	t_key diff = a ^ b;
	int i = offset;

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	if (!diff)
		return 0;
	while ((diff << i) >> (KEYLENGTH-1) == 0)
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		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 |
  -----------------------------------------------------------------
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  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.
  
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  The rest of the bits, from (n->pos + n->bits) onward, are completely unknown
  at this point.

*/

static void check_tnode(struct tnode *tn)
{
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	if (tn && tn->pos+tn->bits > 32) {
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		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);
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	if (l) {
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		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);
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	if (li) {
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		li->plen = plen;
		INIT_LIST_HEAD(&li->falh);
	}
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	return li;
}

static inline void free_leaf(struct leaf *l)
{
	kfree(l);
}

static inline void free_leaf_info(struct leaf_info *li)
{
	kfree(li);
}

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static struct tnode *tnode_alloc(unsigned int size)
{
	if (size <= PAGE_SIZE) {
		return kmalloc(size, GFP_KERNEL);
	} else {
		return (struct tnode *)
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			__get_free_pages(GFP_KERNEL, get_order(size));
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	}
}

static void __tnode_free(struct tnode *tn)
{
	unsigned int size = sizeof(struct tnode) +
	                    (1<<tn->bits) * sizeof(struct node *);

	if (size <= PAGE_SIZE)
		kfree(tn);
	else
		free_pages((unsigned long)tn, get_order(size));
}

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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 *);
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	struct tnode *tn = tnode_alloc(sz);
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	if (tn)  {
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		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;
	}
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	if (trie_debug > 0)
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		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)
{
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	if (!tn) {
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		trie_bug("tnode_free\n");
	}
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	if (IS_LEAF(tn)) {
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		free_leaf((struct leaf *)tn);
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		if (trie_debug > 0 )
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			printk("FL %p \n", tn);
	}
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	else if (IS_TNODE(tn)) {
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		__tnode_free(tn);
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		if (trie_debug > 0 )
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			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)
{
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	if (n == NULL || IS_LEAF(n))
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		return 0;

	return ((struct tnode *) n)->pos == tn->pos + tn->bits;
}

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static inline void put_child(struct trie *t, struct tnode *tn, int i, struct node *n)
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{
	tnode_put_child_reorg(tn, i, n, -1);
}

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 /*
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  * Add a child at position i overwriting the old value.
  * Update the value of full_children and empty_children.
  */

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static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int wasfull)
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{
	struct node *chi;
	int isfull;

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	if (i >= 1<<tn->bits) {
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		printk("bits=%d, i=%d\n", tn->bits, i);
		trie_bug("tnode_put_child_reorg bits");
	}
	write_lock_bh(&fib_lock);
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	chi = tn->child[i];
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	/* update emptyChildren */
	if (n == NULL && chi != NULL)
		tn->empty_children++;
	else if (n != NULL && chi == NULL)
		tn->empty_children--;
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	/* update fullChildren */
        if (wasfull == -1)
		wasfull = tnode_full(tn, chi);

	isfull = tnode_full(tn, n);
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	if (wasfull && !isfull)
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		tn->full_children--;
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	else if (!wasfull && isfull)
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		tn->full_children++;
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	if (n)
		NODE_SET_PARENT(n, tn);
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	tn->child[i] = n;
	write_unlock_bh(&fib_lock);
}

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static struct node *resize(struct trie *t, struct tnode *tn)
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{
	int i;
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	int err = 0;
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 	if (!tn)
		return NULL;

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	if (trie_debug)
		printk("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
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		      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];
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				if (n)
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					NODE_INIT_PARENT(n, NODE_TYPE(n));

				write_unlock_bh(&fib_lock);
				tnode_free(tn);
				return n;
			}
			write_unlock_bh(&fib_lock);
		}
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	/*
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	 * Double as long as the resulting node has a number of
	 * nonempty nodes that are above the threshold.
	 */

	/*
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	 * From "Implementing a dynamic compressed trie" by Stefan Nilsson of
	 * the Helsinki University of Technology and Matti Tikkanen of Nokia
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	 * Telecommunications, page 6:
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	 * "A node is doubled if the ratio of non-empty children to all
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	 * children in the *doubled* node is at least 'high'."
	 *
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	 * '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
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	 * multiply the left-hand side by 50.
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	 *
	 * 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"
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	 * children, that is non-null tnodes with a skip value of 0.
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	 * All of those will be doubled in the resulting inflated tnode, so
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	 * we just count them one extra time here.
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	 *
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	 * A clearer way to write this would be:
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	 *
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	 * to_be_doubled = tn->full_children;
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	 * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
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	 *     tn->full_children;
	 *
	 * new_child_length = tnode_child_length(tn) * 2;
	 *
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	 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
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	 *      new_child_length;
	 * if (new_fill_factor >= inflate_threshold)
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	 *
	 * ...and so on, tho it would mess up the while () loop.
	 *
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	 * anyway,
	 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
	 *      inflate_threshold
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	 *
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	 * avoid a division:
	 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
	 *      inflate_threshold * new_child_length
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	 *
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	 * expand not_to_be_doubled and to_be_doubled, and shorten:
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	 * 100 * (tnode_child_length(tn) - tn->empty_children +
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	 *    tn->full_children ) >= inflate_threshold * new_child_length
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	 *
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	 * expand new_child_length:
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	 * 100 * (tnode_child_length(tn) - tn->empty_children +
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	 *    tn->full_children ) >=
	 *      inflate_threshold * tnode_child_length(tn) * 2
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	 *
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	 * shorten again:
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	 * 50 * (tn->full_children + tnode_child_length(tn) -
	 *    tn->empty_children ) >= inflate_threshold *
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	 *    tnode_child_length(tn)
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	 *
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	 */

	check_tnode(tn);
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	err = 0;
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	while ((tn->full_children > 0 &&
	       50 * (tn->full_children + tnode_child_length(tn) - tn->empty_children) >=
				inflate_threshold * tnode_child_length(tn))) {

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		tn = inflate(t, tn, &err);

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		if (err) {
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#ifdef CONFIG_IP_FIB_TRIE_STATS
			t->stats.resize_node_skipped++;
#endif
			break;
		}
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	}

	check_tnode(tn);

	/*
	 * Halve as long as the number of empty children in this
	 * node is above threshold.
	 */
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	err = 0;
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	while (tn->bits > 1 &&
	       100 * (tnode_child_length(tn) - tn->empty_children) <
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	       halve_threshold * tnode_child_length(tn)) {

		tn = halve(t, tn, &err);

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		if (err) {
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#ifdef CONFIG_IP_FIB_TRIE_STATS
			t->stats.resize_node_skipped++;
#endif
			break;
		}
	}
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	/* Only one child remains */

	if (tn->empty_children == tnode_child_length(tn) - 1)
		for (i = 0; i < tnode_child_length(tn); i++) {
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			write_lock_bh(&fib_lock);
			if (tn->child[i] != NULL) {
				/* compress one level */
				struct node *n = tn->child[i];

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				if (n)
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					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;
}

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static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err)
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{
	struct tnode *inode;
	struct tnode *oldtnode = tn;
	int olen = tnode_child_length(tn);
	int i;

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  	if (trie_debug)
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		printk("In inflate\n");

	tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits + 1);

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	if (!tn) {
		*err = -ENOMEM;
		return oldtnode;
	}

	/*
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	 * 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
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	 * of tnode is ignored.
	 */
669
		
670 671 672 673 674 675 676 677 678 679
	for(i = 0; i < olen; i++) {
		struct tnode *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 = TKEY_GET_MASK(inode->pos, 1);
680

681 682 683
			left = tnode_new(inode->key&(~m), inode->pos + 1,
					 inode->bits - 1);

684 685
			if (!left) {
				*err = -ENOMEM;
686 687
				break;
			}
688
		
689 690 691
			right = tnode_new(inode->key|m, inode->pos + 1,
					  inode->bits - 1);

692 693
			if (!right) {
				*err = -ENOMEM;
694 695 696 697 698 699 700 701
				break;
			}

			put_child(t, tn, 2*i, (struct node *) left);
			put_child(t, tn, 2*i+1, (struct node *) right);
		}
	}

702
	if (*err) {
703 704 705
		int size = tnode_child_length(tn);
		int j;

706 707
		for(j = 0; j < size; j++)
			if (tn->child[j])
708 709 710
				tnode_free((struct tnode *)tn->child[j]);

		tnode_free(tn);
711
	
712 713 714
		*err = -ENOMEM;
		return oldtnode;
	}
715 716 717

	for(i = 0; i < olen; i++) {
		struct node *node = tnode_get_child(oldtnode, i);
718

719 720 721 722 723 724
		/* An empty child */
		if (node == NULL)
			continue;

		/* A leaf or an internal node with skipped bits */

725
		if (IS_LEAF(node) || ((struct tnode *) node)->pos >
726
		   tn->pos + tn->bits - 1) {
727
			if (tkey_extract_bits(node->key, oldtnode->pos + oldtnode->bits,
728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749
					     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;

750 751 752 753 754 755 756 757 758 759 760
			/* 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
761 762
			 * left and right. So... we synthesize that bit in the
			 * two  new keys.
763
			 * The mask 'm' below will be a single "one" bit at
764 765 766
			 * the position (inode->pos)
			 */

767 768
			/* Use the old key, but set the new significant
			 *   bit to zero.
769 770
			 */

771 772 773
			left = (struct tnode *) tnode_get_child(tn, 2*i);
			put_child(t, tn, 2*i, NULL);

774
			if (!left)
775 776 777 778 779
				BUG();

			right = (struct tnode *) tnode_get_child(tn, 2*i+1);
			put_child(t, tn, 2*i+1, NULL);

780
			if (!right)
781
				BUG();
782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797

			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;
}

798
static struct tnode *halve(struct trie *t, struct tnode *tn, int *err)
799 800 801 802 803 804
{
	struct tnode *oldtnode = tn;
	struct node *left, *right;
	int i;
	int olen = tnode_child_length(tn);

805 806 807
	if (trie_debug) printk("In halve\n");

	tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits - 1);
808

809 810 811 812 813 814
	if (!tn) {
		*err = -ENOMEM;
		return oldtnode;
	}

	/*
815 816 817
	 * 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
818 819 820 821 822 823
	 * of tnode is ignored.
	 */

	for(i = 0; i < olen; i += 2) {
		left = tnode_get_child(oldtnode, i);
		right = tnode_get_child(oldtnode, i+1);
824

825
		/* Two nonempty children */
826
		if (left && right)  {
827 828 829
			struct tnode *newBinNode =
				tnode_new(left->key, tn->pos + tn->bits, 1);

830 831
			if (!newBinNode) {
				*err = -ENOMEM;
832 833 834 835 836 837
				break;
			}
			put_child(t, tn, i/2, (struct node *)newBinNode);
		}
	}

838
	if (*err) {
839 840 841
		int size = tnode_child_length(tn);
		int j;

842 843
		for(j = 0; j < size; j++)
			if (tn->child[j])
844 845 846
				tnode_free((struct tnode *)tn->child[j]);

		tnode_free(tn);
847
	
848 849 850
		*err = -ENOMEM;
		return oldtnode;
	}
851 852 853 854

	for(i = 0; i < olen; i += 2) {
		left = tnode_get_child(oldtnode, i);
		right = tnode_get_child(oldtnode, i+1);
855

856 857 858 859 860 861 862
		/* 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);
863

864 865 866
		/* Two nonempty children */
		else {
			struct tnode *newBinNode =
867 868
				(struct tnode *) tnode_get_child(tn, i/2);
			put_child(t, tn, i/2, NULL);
869

870
			if (!newBinNode)
871
				BUG();
872 873 874 875 876 877 878 879 880 881 882 883

			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)
{
884
	if (t) {
885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900
		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) {
901
		if (li->plen == plen)
902 903 904 905 906 907 908
			return li;
	}
	return NULL;
}

static inline struct list_head * get_fa_head(struct leaf *l, int plen)
{
909
	struct list_head *fa_head = NULL;
910
	struct leaf_info *li = find_leaf_info(&l->list, plen);
911 912

	if (li)
913
		fa_head = &li->falh;
914

915 916 917 918 919
	return fa_head;
}

static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
{
920
	struct leaf_info *li = NULL, *last = NULL;
921 922 923
	struct hlist_node *node, *tmp;

	write_lock_bh(&fib_lock);
924 925

	if (hlist_empty(head))
926 927 928
		hlist_add_head(&new->hlist, head);
	else {
		hlist_for_each_entry_safe(li, node, tmp, head, hlist) {
929 930
		
			if (new->plen > li->plen)
931
				break;
932
		
933 934
			last = li;
		}
935
		if (last)
936
			hlist_add_after(&last->hlist, &new->hlist);
937
		else
938 939 940 941 942 943 944 945 946 947 948 949 950
			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;
951
	n = t->trie;
952 953 954

	while (n != NULL &&  NODE_TYPE(n) == T_TNODE) {
		tn = (struct tnode *) n;
955
		
956
		check_tnode(tn);
957 958
		
		if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980
			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;

981
	if (!tn)
982
		BUG();
983

984 985 986 987 988
	key = tn->key;
	i = 0;

	while (tn != NULL && NODE_PARENT(tn) != NULL) {

989
		if (i > 10) {
990
			printk("Rebalance tn=%p \n", tn);
991 992
			if (tn) 		printk("tn->parent=%p \n", NODE_PARENT(tn));
		
993
			printk("Rebalance tp=%p \n", tp);
994
			if (tp) 		printk("tp->parent=%p \n", NODE_PARENT(tp));
995 996
		}

997
		if (i > 12) BUG();
998 999 1000 1001 1002 1003 1004
		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);
1005 1006
	
		if (!NODE_PARENT(tn))
1007 1008 1009 1010 1011
			break;

		tn = NODE_PARENT(tn);
	}
	/* Handle last (top) tnode */
1012
	if (IS_TNODE(tn))
1013 1014 1015 1016 1017
		tn = (struct tnode*) resize(t, (struct tnode *)tn);

	return (struct node*) tn;
}

1018 1019
static  struct list_head *
fib_insert_node(struct trie *t, int *err, u32 key, int plen)
1020 1021 1022 1023 1024 1025
{
	int pos, newpos;
	struct tnode *tp = NULL, *tn = NULL;
	struct node *n;
	struct leaf *l;
	int missbit;
1026
	struct list_head *fa_head = NULL;
1027 1028 1029 1030
	struct leaf_info *li;
	t_key cindex;

	pos = 0;
1031
	n = t->trie;
1032

1033 1034
	/* 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,
1035
	 * and we should just put our new leaf in that.
1036 1037
	 * 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
1038 1039
	 * not be the parent's 'pos'+'bits'!
	 *
1040
	 * If it does match the current key, get pos/bits from it, extract
1041 1042 1043 1044
	 * 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.
	 *
1045 1046 1047
	 * 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.
1048 1049 1050 1051 1052 1053
	 * 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;
		
1054 1055 1056
		check_tnode(tn);
	
		if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
1057 1058 1059 1060
			tp = tn;
			pos=tn->pos + tn->bits;
			n = tnode_get_child(tn, tkey_extract_bits(key, tn->pos, tn->bits));

1061
			if (n && NODE_PARENT(n) != tn) {
1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072
				printk("BUG tn=%p, n->parent=%p\n", tn, NODE_PARENT(n));
				BUG();
			}
		}
		else
			break;
	}

	/*
	 * n  ----> NULL, LEAF or TNODE
	 *
1073
	 * tp is n's (parent) ----> NULL or TNODE
1074 1075
	 */

1076
	if (tp && IS_LEAF(tp))
1077 1078 1079 1080 1081
		BUG();


	/* Case 1: n is a leaf. Compare prefixes */

1082
	if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key)) {
1083
		struct leaf *l = ( struct leaf *)  n;
1084
	
1085
		li = leaf_info_new(plen);
1086 1087
	
		if (!li) {
1088 1089 1090
			*err = -ENOMEM;
			goto err;
		}
1091 1092 1093 1094 1095 1096 1097 1098

		fa_head = &li->falh;
		insert_leaf_info(&l->list, li);
		goto done;
	}
	t->size++;
	l = leaf_new();

1099
	if (!l) {
1100 1101 1102
		*err = -ENOMEM;
		goto err;
	}
1103 1104 1105 1106

	l->key = key;
	li = leaf_info_new(plen);

1107
	if (!li) {
1108 1109 1110 1111
		tnode_free((struct tnode *) l);
		*err = -ENOMEM;
		goto err;
	}
1112 1113 1114 1115 1116 1117 1118 1119

	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);
1120 1121
	
		if (!tp)
1122 1123 1124 1125 1126 1127 1128 1129 1130
			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 {
1131 1132
		/*
		 *  Add a new tnode here
1133 1134 1135 1136 1137 1138 1139
		 *  first tnode need some special handling
		 */

		if (tp)
			pos=tp->pos+tp->bits;
		else
			pos=0;
1140
		if (n) {
1141 1142 1143 1144 1145
			newpos = tkey_mismatch(key, pos, n->key);
			tn = tnode_new(n->key, newpos, 1);
		}
		else {
			newpos = 0;
1146
			tn = tnode_new(key, newpos, 1); /* First tnode */
1147 1148
		}

1149
		if (!tn) {
1150 1151 1152 1153
			free_leaf_info(li);
			tnode_free((struct tnode *) l);
			*err = -ENOMEM;
			goto err;
1154 1155
		}		
		
1156 1157 1158 1159 1160 1161
		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);

1162
		if (tp) {
1163 1164 1165
			cindex = tkey_extract_bits(key, tp->pos, tp->bits);
			put_child(t, (struct tnode *)tp, cindex, (struct node *)tn);
		}
1166
		else {
1167 1168 1169 1170
			t->trie = (struct node*) tn; /* First tnode */
			tp = tn;
		}
	}
1171 1172
	if (tp && tp->pos+tp->bits > 32) {
		printk("ERROR tp=%p pos=%d, bits=%d, key=%0x plen=%d\n",
1173 1174 1175 1176
		       tp, tp->pos, tp->bits, key, plen);
	}
	/* Rebalance the trie */
	t->trie = trie_rebalance(t, tp);
1177 1178 1179
done:
	t->revision++;
err:;
1180 1181 1182 1183 1184 1185 1186 1187 1188
	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;
1189
	struct list_head *fa_head = NULL;
1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201
	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;
1202
	if (rta->rta_dst)
1203 1204 1205 1206
		memcpy(&key, rta->rta_dst, 4);

	key = ntohl(key);

1207
	if (trie_debug)
1208 1209
		printk("Insert table=%d %08x/%d\n", tb->tb_id, key, plen);

1210
	mask = ntohl( inet_make_mask(plen) );
1211

1212
	if (key & ~mask)
1213 1214 1215 1216 1217 1218 1219 1220
		return -EINVAL;

	key = key & mask;

	if  ((fi = fib_create_info(r, rta, nlhdr, &err)) == NULL)
		goto err;

	l = fib_find_node(t, key);
1221
	fa = NULL;
1222

1223
	if (l) {
1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301
		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
1302
	new_fa->dst = NULL;
1303 1304 1305 1306 1307
#endif
	/*
	 * Insert new entry to the list.
	 */

1308
	if (!fa_head) {
1309 1310
		fa_head = fib_insert_node(t, &err, key, plen);
		err = 0;
1311
		if (err)
1312 1313
			goto out_free_new_fa;
	}
1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325

	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;
1326 1327 1328

out_free_new_fa:
	kmem_cache_free(fn_alias_kmem, new_fa);
1329 1330
out:
	fib_release_info(fi);
1331
err:;
1332 1333 1334
	return err;
}

1335
static inline int check_leaf(struct trie *t, struct leaf *l,  t_key key, int *plen, const struct flowi *flp,
1336
			     struct fib_result *res)
1337
{
1338
	int err, i;
1339 1340 1341 1342
	t_key mask;
	struct leaf_info *li;
	struct hlist_head *hhead = &l->list;
	struct hlist_node *node;
1343

1344 1345 1346 1347
	hlist_for_each_entry(li, node, hhead, hlist) {

		i = li->plen;
		mask = ntohl(inet_make_mask(i));
1348
		if (l->key != (key & mask))
1349 1350
			continue;

1351
		if ((err = fib_semantic_match(&li->falh, flp, res, l->key, mask, i)) <= 0) {
1352 1353 1354 1355
			*plen = i;
#ifdef CONFIG_IP_FIB_TRIE_STATS
			t->stats.semantic_match_passed++;
#endif
1356
			return err;
1357 1358 1359 1360 1361
		}
#ifdef CONFIG_IP_FIB_TRIE_STATS
		t->stats.semantic_match_miss++;
#endif
	}
1362
	return 1;
1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379
}

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);
1380
	if (!n)
1381 1382 1383 1384 1385 1386 1387 1388
		goto failed;

#ifdef CONFIG_IP_FIB_TRIE_STATS
	t->stats.gets++;
#endif

	/* Just a leaf? */
	if (IS_LEAF(n)) {
1389
		if ((ret = check_leaf(t, (struct leaf *)n, key, &plen, flp, res)) <= 0)
1390 1391 1392 1393 1394
			goto found;
		goto failed;
	}
	pn = (struct tnode *) n;
	chopped_off = 0;
1395

1396 1397 1398 1399 1400
        while (pn) {

		pos = pn->pos;
		bits = pn->bits;

1401
		if (!chopped_off)
1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420
			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;

			/*
1421
			 * It's a tnode, and we can do some extra checks here if we
1422
			 * like, to avoid descending into a dead-end branch.
1423 1424 1425
			 * 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
1426
			 * subprefix, padded with zero at the end.
1427 1428
			 * We can also take a look at any skipped bits in this
			 * tnode - everything up to p_pos is supposed to be ok,
1429
			 * and the non-chopped bits of the index (se previous
1430
			 * paragraph) are also guaranteed ok, but the rest is
1431 1432 1433 1434
			 * considered unknown.
			 *
			 * The skipped bits are key[pos+bits..cn->pos].
			 */
1435 1436 1437 1438 1439
		
			/* 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
1440
			 * prefix present. Here we can only check the skipped
1441 1442
			 * bits. Remember, since we have already indexed into the
			 * parent's child array, we know that the bits we chopped of
1443 1444 1445 1446
			 * *are* zero.
			 */

			/* NOTA BENE: CHECKING ONLY SKIPPED BITS FOR THE NEW NODE HERE */
1447
		
1448 1449 1450 1451 1452 1453 1454 1455
			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;
			}

			/*
1456 1457
			 * If chopped_off=0, the index is fully validated and we
			 * only need to look at the skipped bits for this, the new,
1458 1459
			 * tnode. What we actually want to do is to find out if
			 * these skipped bits match our key perfectly, or if we will
1460 1461 1462
			 * 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.
1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473
			 */

			/* 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.
			 */

1474 1475 1476 1477 1478 1479 1480
			/* 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
1481 1482 1483 1484
			 * to find a matching prefix.
			 */

			node_prefix = MASK_PFX(cn->key, cn->pos);
1485
			key_prefix = MASK_PFX(key, cn->pos);
1486 1487 1488
			pref_mismatch = key_prefix^node_prefix;
			mp = 0;

1489
			/* In short: If skipped bits in this node do not match the search
1490 1491 1492 1493 1494 1495 1496 1497
			 * 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);
1498
			
1499 1500 1501 1502 1503 1504 1505 1506 1507 1508
				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;
1509 1510
		}
		if (IS_LEAF(n)) {
1511
			if ((ret = check_leaf(t, (struct leaf *)n, key, &plen, flp, res)) <= 0)
1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524
				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;
1525
	
1526
		/*
1527
		 * Either we do the actual chop off according or if we have
1528 1529 1530
		 * chopped off all bits in this tnode walk up to our parent.
		 */

1531
		if (chopped_off <= pn->bits)
1532 1533
			cindex &= ~(1 << (chopped_off-1));
		else {
1534
			if (NODE_PARENT(pn) == NULL)
1535
				goto failed;
1536
		
1537 1538 1539 1540 1541 1542 1543 1544 1545
			/* 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;
1546
		}
1547 1548
	}
failed:
1549
	ret = 1;
1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561
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;

1562
	if (trie_debug)
1563 1564 1565
		printk("entering trie_leaf_remove(%p)\n", n);

	/* Note that in the case skipped bits, those bits are *not* checked!
1566
	 * When we finish this, we will have NULL or a T_LEAF, and the
1567 1568 1569 1570 1571 1572 1573 1574
	 * 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));

1575
			if (n && NODE_PARENT(n) != tn) {
1576 1577 1578 1579 1580 1581
				printk("BUG tn=%p, n->parent=%p\n", tn, NODE_PARENT(n));
				BUG();
			}
        }
	l = (struct leaf *) n;

1582
	if (!n || !tkey_equals(l->key, key))
1583
		return 0;
1584 1585 1586 1587

	/*
	 * Key found.
	 * Remove the leaf and rebalance the tree
1588 1589 1590 1591 1592 1593 1594 1595
	 */

	t->revision++;
	t->size--;

	tp = NODE_PARENT(n);
	tnode_free((struct tnode *) n);

1596
	if (tp) {
1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618
		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;

1619
	if (plen > 32)
1620 1621 1622
		return -EINVAL;

	key = 0;
1623
	if (rta->rta_dst)
1624 1625 1626
		memcpy(&key, rta->rta_dst, 4);

	key = ntohl(key);
1627
	mask = ntohl( inet_make_mask(plen) );
1628

1629
	if (key & ~mask)
1630 1631 1632 1633 1634
		return -EINVAL;

	key = key & mask;
	l = fib_find_node(t, key);

1635
	if (!l)
1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680
		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);

1681
		if (list_empty(fa_head)) {
1682 1683 1684 1685
			hlist_del(&li->hlist);
			kill_li = 1;
		}
		write_unlock_bh(&fib_lock);
1686 1687
	
		if (kill_li)
1688 1689
			free_leaf_info(li);

1690
		if (hlist_empty(&l->list))
1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708
			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;
1709
	
1710 1711
		if (fi && (fi->fib_flags&RTNH_F_DEAD)) {

1712
 			write_lock_bh(&fib_lock);
1713
			list_del(&fa->fa_list);
1714
			write_unlock_bh(&fib_lock);
1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730

			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) {
1731
		
1732 1733 1734 1735
		found += trie_flush_list(t, &li->falh);

		if (list_empty(&li->falh)) {

1736
 			write_lock_bh(&fib_lock);
1737
			hlist_del(&li->hlist);
1738
			write_unlock_bh(&fib_lock);
1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751

			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;

1752 1753
	if (c == NULL) {
		if (t->trie == NULL)
1754 1755 1756 1757 1758 1759 1760
			return NULL;

		if (IS_LEAF(t->trie))          /* trie w. just a leaf */
			return (struct leaf *) t->trie;

		p = (struct tnode*) t->trie;  /* Start */
	}
1761
	else
1762
		p = (struct tnode *) NODE_PARENT(c);
1763

1764 1765 1766 1767
	while (p) {
		int pos, last;

		/*  Find the next child of the parent */
1768 1769 1770
		if (c)
			pos = 1 + tkey_extract_bits(c->key, p->pos, p->bits);
		else
1771 1772 1773 1774
			pos = 0;

		last = 1 << p->bits;
		for(idx = pos; idx < last ; idx++) {
1775
			if (p->child[idx]) {
1776 1777 1778 1779 1780 1781

				/* Decend if tnode */

				while (IS_TNODE(p->child[idx])) {
					p = (struct tnode*) p->child[idx];
					idx = 0;
1782
				
1783
					/* Rightmost non-NULL branch */
1784 1785
					if (p && IS_TNODE(p))
						while (p->child[idx] == NULL && idx < (1 << p->bits)) idx++;
1786 1787

					/* Done with this tnode? */
1788
					if (idx >= (1 << p->bits) || p->child[idx] == NULL )
1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820
						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);

1821
	if (trie_debug)
1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843
		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);
1844

1845
	l = fib_find_node(t, 0);
1846
	if (!l)
1847 1848 1849
		goto out;

	fa_head = get_fa_head(l, 0);
1850
	if (!fa_head)
1851 1852
		goto out;

1853
	if (list_empty(fa_head))
1854 1855 1856 1857
		goto out;

	list_for_each_entry(fa, fa_head, fa_list) {
		struct fib_info *next_fi = fa->fa_info;
1858
	
1859 1860 1861
		if (fa->fa_scope != res->scope ||
		    fa->fa_type != RTN_UNICAST)
			continue;
1862
	
1863 1864 1865 1866 1867 1868
		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;
1869
	
1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906
		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:;
1907
	read_unlock(&fib_lock);
1908 1909
}

1910
static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah, struct fib_table *tb,
1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945
			   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,
1946
				  fa->fa_info, 0) < 0) {
1947 1948 1949 1950 1951 1952 1953 1954 1955
			cb->args[3] = i;
			return -1;
			}
		i++;
	}
	cb->args[3]=i;
	return skb->len;
}

1956
static int fn_trie_dump_plen(struct trie *t, int plen, struct fib_table *tb, struct sk_buff *skb,
1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972
			     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);
1973 1974
	
		if (!fa_head)
1975 1976
			continue;

1977
		if (list_empty(fa_head))
1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052
			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);

2053 2054 2055 2056
	if (id == RT_TABLE_LOCAL)
                trie_local = t;
	else if (id == RT_TABLE_MAIN)
                trie_main = t;
2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076

	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");
}

2077
static void printnode_seq(struct seq_file *seq, int indent, struct node *n,
2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094
		   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))
2095
		seq_printf(seq, "key=%d.%d.%d.%d\n",
2096 2097
			   n->key >> 24, (n->key >> 16) % 256, (n->key >> 8) % 256, n->key % 256);
	else {
2098
		int plen = ((struct tnode *)n)->pos;
2099
		t_key prf=MASK_PFX(n->key, plen);
2100
		seq_printf(seq, "key=%d.%d.%d.%d/%d\n",
2101 2102 2103 2104 2105 2106 2107
			   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--)
2108 2109
		  if (find_leaf_info(&l->list, i)) {
		
2110
				struct list_head *fa_head = get_fa_head(l, i);
2111 2112
			
				if (!fa_head)
2113 2114
					continue;

2115
				if (list_empty(fa_head))
2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140
					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)) {
2141
		struct tnode *tn = (struct tnode *)n;
2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156
		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)
{
2157
	struct node *n = t->trie;
2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168
	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)) {
2169
			struct tnode *tn = (struct tnode *)n;
2170 2171 2172 2173 2174 2175 2176
			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]) {
2177
				
2178
					/* Got a child */
2179
				
2180
					printnode_seq(seq, indent, tn->child[cindex], pend, cindex, tn->bits);
2181
					if (IS_LEAF(tn->child[cindex])) {
2182
						cindex++;
2183
					
2184 2185
					}
					else {
2186 2187
						/*
						 * New tnode. Decend one level
2188
						 */
2189
					
2190
						depth++;
2191 2192 2193
						n = tn->child[cindex];
						tn = (struct tnode *)n;
						pend = tn->pos+tn->bits;
2194 2195 2196 2197 2198
						putspace_seq(seq, indent); seq_printf(seq, "\\--\n");
						indent+=3;
						cindex=0;
					}
				}
2199
				else
2200 2201 2202
					cindex++;

				/*
2203
				 * Test if we are done
2204
				 */
2205
			
2206 2207 2208 2209 2210 2211
				while (cindex >= (1 << tn->bits)) {

					/*
					 * Move upwards and test for root
					 * pop off all traversed  nodes
					 */
2212
				
2213 2214 2215 2216 2217 2218 2219 2220 2221
					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++;
2222 2223
						n = (struct node *)tn;
						pend = tn->pos+tn->bits;
2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240
						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;
2241 2242

	if (s) {
2243 2244 2245 2246 2247
		s->totdepth = 0;
		s->maxdepth = 0;
		s->tnodes = 0;
		s->leaves = 0;
		s->nullpointers = 0;
2248
	
2249 2250 2251 2252
		for(i=0; i< MAX_CHILDS; i++)
			s->nodesizes[i] = 0;
	}
	return s;
2253
}
2254 2255 2256

static struct trie_stat *trie_collect_stats(struct trie *t)
{
2257
	struct node *n = t->trie;
2258 2259 2260 2261 2262 2263
	struct trie_stat *s = trie_stat_new();
	int cindex = 0;
	int indent = 1;
	int pend = 0;
	int depth = 0;

2264
	read_lock(&fib_lock);	
2265 2266 2267 2268 2269

	if (s) {
		if (n) {
			if (IS_TNODE(n)) {
				struct tnode *tn = (struct tnode *)n;
2270
				pend = tn->pos+tn->bits;
2271 2272 2273 2274 2275 2276 2277
				indent += 3;
				s->nodesizes[tn->bits]++;
				depth++;

				while (tn && cindex < (1 << tn->bits)) {
					if (tn->child[cindex]) {
						/* Got a child */
2278 2279
				
						if (IS_LEAF(tn->child[cindex])) {
2280
							cindex++;
2281
					
2282 2283 2284 2285 2286 2287
							/* stats */
							if (depth > s->maxdepth)
								s->maxdepth = depth;
							s->totdepth += depth;
							s->leaves++;
						}
2288
				
2289
						else {
2290 2291
							/*
							 * New tnode. Decend one level
2292
							 */
2293
					
2294 2295 2296
							s->tnodes++;
							s->nodesizes[tn->bits]++;
							depth++;
2297
					
2298 2299 2300 2301 2302 2303 2304 2305 2306 2307
							n = tn->child[cindex];
							tn = (struct tnode *)n;
							pend = tn->pos+tn->bits;

							indent += 3;
							cindex = 0;
						}
					}
					else {
						cindex++;
2308
						s->nullpointers++;
2309 2310 2311
					}

					/*
2312
					 * Test if we are done
2313
					 */
2314
			
2315 2316 2317 2318 2319 2320 2321
					while (cindex >= (1 << tn->bits)) {

						/*
						 * Move upwards and test for root
						 * pop off all traversed  nodes
						 */

2322
					
2323 2324 2325 2326 2327 2328 2329 2330
						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);
2331
							cindex++;
2332
							n = (struct node *)tn;
2333
							pend = tn->pos+tn->bits;
2334 2335 2336 2337 2338 2339 2340 2341 2342 2343
							indent -= 3;
							depth--;
						}
 					}
				}
			}
			else n = NULL;
		}
	}

2344
	read_unlock(&fib_lock);	
2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379
	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)
{

}

2380
/*
2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405
 *	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);
2406
			
2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417
		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;

2418
		for (i = 1; i <= max; i++)
2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438
			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);
2439
	seq_printf(seq,"skipped node resize = %d\n", t->stats.resize_node_skipped);
2440 2441 2442 2443 2444 2445 2446 2447 2448
#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];
2449

2450
	if (v == SEQ_START_TOKEN) {
2451
		seq_printf(seq, "Basic info: size of leaf: %Zd bytes, size of tnode: %Zd bytes.\n",
2452
			   sizeof(struct leaf), sizeof(struct tnode));
2453
		if (trie_local)
2454 2455
			collect_and_show(trie_local, seq);

2456
		if (trie_main)
2457 2458 2459 2460 2461
			collect_and_show(trie_main, seq);
	}
	else {
		snprintf(bf, sizeof(bf),
			 "*\t%08X\t%08X", 200, 400);
2462
	
2463 2464 2465 2466 2467 2468
		seq_printf(seq, "%-127s\n", bf);
	}
	return 0;
}

static struct seq_operations fib_triestat_seq_ops = {
2469 2470 2471 2472
	.start = fib_triestat_seq_start,
	.next  = fib_triestat_seq_next,
	.stop  = fib_triestat_seq_stop,
	.show  = fib_triestat_seq_show,
2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483
};

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;

2484
	seq = file->private_data;
2485 2486 2487 2488 2489 2490 2491
out:
	return rc;
out_kfree:
	goto out;
}

static struct file_operations fib_triestat_seq_fops = {
2492 2493 2494 2495 2496
	.owner	= THIS_MODULE,
	.open	= fib_triestat_seq_open,
	.read	= seq_read,
	.llseek	= seq_lseek,
	.release = seq_release_private,
2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540
};

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)
{

}

2541
/*
2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552
 *	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) {
2553
		if (trie_local)
2554 2555
			trie_dump_seq(seq, trie_local);

2556
		if (trie_main)
2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569
			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 = {
2570 2571 2572 2573
	.start = fib_trie_seq_start,
	.next  = fib_trie_seq_next,
	.stop  = fib_trie_seq_stop,
	.show  = fib_trie_seq_show,
2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584
};

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;

2585
	seq = file->private_data;
2586 2587 2588 2589 2590 2591 2592
out:
	return rc;
out_kfree:
	goto out;
}

static struct file_operations fib_trie_seq_fops = {
2593 2594 2595 2596 2597
	.owner	= THIS_MODULE,
	.open	= fib_trie_seq_open,
	.read	= seq_read,
	.llseek	= seq_lseek,
	.release= seq_release_private,
2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612
};

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 */