net/ipv4/fib_trie.c

   1 /*
   2  *   This program is free software; you can redistribute it and/or
   3  *   modify it under the terms of the GNU General Public License
   4  *   as published by the Free Software Foundation; either version
   5  *   2 of the License, or (at your option) any later version.
   6  *
   7  *   Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet
   8  *     & Swedish University of Agricultural Sciences.
   9  *
  10  *   Jens Laas <jens.laas@data.slu.se> Swedish University of
  11  *     Agricultural Sciences.
  12  *
  13  *   Hans Liss <hans.liss@its.uu.se>  Uppsala Universitet
  14  *
  15  * This work is based on the LPC-trie which is originally descibed in:
  16  *
  17  * An experimental study of compression methods for dynamic tries
  18  * Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
  19  * http://www.nada.kth.se/~snilsson/public/papers/dyntrie2/
  20  *
  21  *
  22  * IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
  23  * IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
  24  *
  25  * Version:     $Id: fib_trie.c,v 1.3 2005/06/08 14:20:01 robert Exp $
  26  *
  27  *
  28  * Code from fib_hash has been reused which includes the following header:
  29  *
  30  *
  31  * INET         An implementation of the TCP/IP protocol suite for the LINUX
  32  *              operating system.  INET is implemented using the  BSD Socket
  33  *              interface as the means of communication with the user level.
  34  *
  35  *              IPv4 FIB: lookup engine and maintenance routines.
  36  *
  37  *
  38  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  39  *
  40  *              This program is free software; you can redistribute it and/or
  41  *              modify it under the terms of the GNU General Public License
  42  *              as published by the Free Software Foundation; either version
  43  *              2 of the License, or (at your option) any later version.
  44  */
  45
  46 #define VERSION "0.325"
  47
  48 #include <linux/config.h>
  49 #include <asm/uaccess.h>
  50 #include <asm/system.h>
  51 #include <asm/bitops.h>
  52 #include <linux/types.h>
  53 #include <linux/kernel.h>
  54 #include <linux/sched.h>
  55 #include <linux/mm.h>
  56 #include <linux/string.h>
  57 #include <linux/socket.h>
  58 #include <linux/sockios.h>
  59 #include <linux/errno.h>
  60 #include <linux/in.h>
  61 #include <linux/inet.h>
  62 #include <linux/netdevice.h>
  63 #include <linux/if_arp.h>
  64 #include <linux/proc_fs.h>
  65 #include <linux/skbuff.h>
  66 #include <linux/netlink.h>
  67 #include <linux/init.h>
  68 #include <linux/list.h>
  69 #include <net/ip.h>
  70 #include <net/protocol.h>
  71 #include <net/route.h>
  72 #include <net/tcp.h>
  73 #include <net/sock.h>
  74 #include <net/ip_fib.h>
  75 #include "fib_lookup.h"
  76
  77 #undef CONFIG_IP_FIB_TRIE_STATS
  78 #define MAX_CHILDS 16384
  79
  80 #define EXTRACT(p, n, str) ((str)<<(p)>>(32-(n)))
  81 #define KEYLENGTH (8*sizeof(t_key))
  82 #define MASK_PFX(k, l) (((l)==0)?0:(k >> (KEYLENGTH-l)) << (KEYLENGTH-l))
  83 #define TKEY_GET_MASK(offset, bits) (((bits)==0)?0:((t_key)(-1) << (KEYLENGTH - bits) >> offset))
  84
  85 static DEFINE_RWLOCK(fib_lock);
  86
  87 typedef unsigned int t_key;
  88
  89 #define T_TNODE 0
  90 #define T_LEAF  1
  91 #define NODE_TYPE_MASK  0x1UL
  92 #define NODE_PARENT(_node) \
  93         ((struct tnode *)((_node)->_parent & ~NODE_TYPE_MASK))
  94 #define NODE_SET_PARENT(_node, _ptr) \
  95         ((_node)->_parent = (((unsigned long)(_ptr)) | \
  96                      ((_node)->_parent & NODE_TYPE_MASK)))
  97 #define NODE_INIT_PARENT(_node, _type) \
  98         ((_node)->_parent = (_type))
  99 #define NODE_TYPE(_node) \
 100         ((_node)->_parent & NODE_TYPE_MASK)
 101
 102 #define IS_TNODE(n) (!(n->_parent & T_LEAF))
 103 #define IS_LEAF(n) (n->_parent & T_LEAF)
 104
 105 struct node {
 106         t_key key;
 107         unsigned long _parent;
 108 };
 109
 110 struct leaf {
 111         t_key key;
 112         unsigned long _parent;
 113         struct hlist_head list;
 114 };
 115
 116 struct leaf_info {
 117         struct hlist_node hlist;
 118         int plen;
 119         struct list_head falh;
 120 };
 121
 122 struct tnode {
 123         t_key key;
 124         unsigned long _parent;
 125         unsigned short pos:5;        /* 2log(KEYLENGTH) bits needed */
 126         unsigned short bits:5;       /* 2log(KEYLENGTH) bits needed */
 127         unsigned short full_children;  /* KEYLENGTH bits needed */
 128         unsigned short empty_children; /* KEYLENGTH bits needed */
 129         struct node *child[0];
 130 };
 131
 132 #ifdef CONFIG_IP_FIB_TRIE_STATS
 133 struct trie_use_stats {
 134         unsigned int gets;
 135         unsigned int backtrack;
 136         unsigned int semantic_match_passed;
 137         unsigned int semantic_match_miss;
 138         unsigned int null_node_hit;
 139         unsigned int resize_node_skipped;
 140 };
 141 #endif
 142
 143 struct trie_stat {
 144         unsigned int totdepth;
 145         unsigned int maxdepth;
 146         unsigned int tnodes;
 147         unsigned int leaves;
 148         unsigned int nullpointers;
 149         unsigned int nodesizes[MAX_CHILDS];
 150 };
 151
 152 struct trie {
 153         struct node *trie;
 154 #ifdef CONFIG_IP_FIB_TRIE_STATS
 155         struct trie_use_stats stats;
 156 #endif
 157         int size;
 158         unsigned int revision;
 159 };
 160
 161 static int trie_debug = 0;
 162
 163 static int tnode_full(struct tnode *tn, struct node *n);
 164 static void put_child(struct trie *t, struct tnode *tn, int i, struct node *n);
 165 static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int wasfull);
 166 static int tnode_child_length(struct tnode *tn);
 167 static struct node *resize(struct trie *t, struct tnode *tn);
 168 static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err);
 169 static struct tnode *halve(struct trie *t, struct tnode *tn, int *err);
 170 static void tnode_free(struct tnode *tn);
 171 static void trie_dump_seq(struct seq_file *seq, struct trie *t);
 172 extern struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio);
 173 extern int fib_detect_death(struct fib_info *fi, int order,
 174                             struct fib_info **last_resort, int *last_idx, int *dflt);
 175
 176 extern void rtmsg_fib(int event, u32 key, struct fib_alias *fa, int z, int tb_id,
 177                struct nlmsghdr *n, struct netlink_skb_parms *req);
 178
 179 static kmem_cache_t *fn_alias_kmem;
 180 static struct trie *trie_local = NULL, *trie_main = NULL;
 181
 182 static void trie_bug(char *err)
 183 {
 184         printk("Trie Bug: %s\n", err);
 185         BUG();
 186 }
 187
 188 static inline struct node *tnode_get_child(struct tnode *tn, int i)
 189 {
 190         if (i >= 1<<tn->bits)
 191                 trie_bug("tnode_get_child");
 192
 193         return tn->child[i];
 194 }
 195
 196 static inline int tnode_child_length(struct tnode *tn)
 197 {
 198         return 1<<tn->bits;
 199 }
 200
 201 /*
 202   _________________________________________________________________
 203   | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
 204   ----------------------------------------------------------------
 205     0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
 206
 207   _________________________________________________________________
 208   | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
 209   -----------------------------------------------------------------
 210    16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31
 211
 212   tp->pos = 7
 213   tp->bits = 3
 214   n->pos = 15
 215   n->bits=4
 216   KEYLENGTH=32
 217 */
 218
 219 static inline t_key tkey_extract_bits(t_key a, int offset, int bits)
 220 {
 221         if (offset < KEYLENGTH)
 222                 return ((t_key)(a << offset)) >> (KEYLENGTH - bits);
 223         else
 224                 return 0;
 225 }
 226
 227 static inline int tkey_equals(t_key a, t_key b)
 228 {
 229         return a == b;
 230 }
 231
 232 static inline int tkey_sub_equals(t_key a, int offset, int bits, t_key b)
 233 {
 234         if (bits == 0 || offset >= KEYLENGTH)
 235                 return 1;
 236         bits = bits > KEYLENGTH ? KEYLENGTH : bits;
 237         return ((a ^ b) << offset) >> (KEYLENGTH - bits) == 0;
 238 }
 239
 240 static inline int tkey_mismatch(t_key a, int offset, t_key b)
 241 {
 242         t_key diff = a ^ b;
 243         int i = offset;
 244
 245         if (!diff)
 246                 return 0;
 247         while ((diff << i) >> (KEYLENGTH-1) == 0)
 248                 i++;
 249         return i;
 250 }
 251
 252 /* Candiate for fib_semantics */
 253
 254 static void fn_free_alias(struct fib_alias *fa)
 255 {
 256         fib_release_info(fa->fa_info);
 257         kmem_cache_free(fn_alias_kmem, fa);
 258 }
 259
 260 /*
 261   To understand this stuff, an understanding of keys and all their bits is
 262   necessary. Every node in the trie has a key associated with it, but not
 263   all of the bits in that key are significant.
 264
 265   Consider a node 'n' and its parent 'tp'.
 266
 267   If n is a leaf, every bit in its key is significant. Its presence is
 268   necessitaded by path compression, since during a tree traversal (when
 269   searching for a leaf - unless we are doing an insertion) we will completely
 270   ignore all skipped bits we encounter. Thus we need to verify, at the end of
 271   a potentially successful search, that we have indeed been walking the
 272   correct key path.
 273
 274   Note that we can never "miss" the correct key in the tree if present by
 275   following the wrong path. Path compression ensures that segments of the key
 276   that are the same for all keys with a given prefix are skipped, but the
 277   skipped part *is* identical for each node in the subtrie below the skipped
 278   bit! trie_insert() in this implementation takes care of that - note the
 279   call to tkey_sub_equals() in trie_insert().
 280
 281   if n is an internal node - a 'tnode' here, the various parts of its key
 282   have many different meanings.
 283
 284   Example:
 285   _________________________________________________________________
 286   | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
 287   -----------------------------------------------------------------
 288     0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
 289
 290   _________________________________________________________________
 291   | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
 292   -----------------------------------------------------------------
 293    16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31
 294
 295   tp->pos = 7
 296   tp->bits = 3
 297   n->pos = 15
 298   n->bits=4
 299
 300   First, let's just ignore the bits that come before the parent tp, that is
 301   the bits from 0 to (tp->pos-1). They are *known* but at this point we do
 302   not use them for anything.
 303
 304   The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
 305   index into the parent's child array. That is, they will be used to find
 306   'n' among tp's children.
 307
 308   The bits from (tp->pos + tp->bits) to (n->pos - 1) - "S" - are skipped bits
 309   for the node n.
 310
 311   All the bits we have seen so far are significant to the node n. The rest
 312   of the bits are really not needed or indeed known in n->key.
 313
 314   The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
 315   n's child array, and will of course be different for each child.
 316
 317
 318   The rest of the bits, from (n->pos + n->bits) onward, are completely unknown
 319   at this point.
 320
 321 */
 322
 323 static void check_tnode(struct tnode *tn)
 324 {
 325         if (tn && tn->pos+tn->bits > 32) {
 326                 printk("TNODE ERROR tn=%p, pos=%d, bits=%d\n", tn, tn->pos, tn->bits);
 327         }
 328 }
 329
 330 static int halve_threshold = 25;
 331 static int inflate_threshold = 50;
 332
 333 static struct leaf *leaf_new(void)
 334 {
 335         struct leaf *l = kmalloc(sizeof(struct leaf),  GFP_KERNEL);
 336         if (l) {
 337                 NODE_INIT_PARENT(l, T_LEAF);
 338                 INIT_HLIST_HEAD(&l->list);
 339         }
 340         return l;
 341 }
 342
 343 static struct leaf_info *leaf_info_new(int plen)
 344 {
 345         struct leaf_info *li = kmalloc(sizeof(struct leaf_info),  GFP_KERNEL);
 346         if (li) {
 347                 li->plen = plen;
 348                 INIT_LIST_HEAD(&li->falh);
 349         }
 350         return li;
 351 }
 352
 353 static inline void free_leaf(struct leaf *l)
 354 {
 355         kfree(l);
 356 }
 357
 358 static inline void free_leaf_info(struct leaf_info *li)
 359 {
 360         kfree(li);
 361 }
 362
 363 static struct tnode *tnode_alloc(unsigned int size)
 364 {
 365         if (size <= PAGE_SIZE) {
 366                 return kmalloc(size, GFP_KERNEL);
 367         } else {
 368                 return (struct tnode *)
 369                         __get_free_pages(GFP_KERNEL, get_order(size));
 370         }
 371 }
 372
 373 static void __tnode_free(struct tnode *tn)
 374 {
 375         unsigned int size = sizeof(struct tnode) +
 376                             (1<<tn->bits) * sizeof(struct node *);
 377
 378         if (size <= PAGE_SIZE)
 379                 kfree(tn);
 380         else
 381                 free_pages((unsigned long)tn, get_order(size));
 382 }
 383
 384 static struct tnode* tnode_new(t_key key, int pos, int bits)
 385 {
 386         int nchildren = 1<<bits;
 387         int sz = sizeof(struct tnode) + nchildren * sizeof(struct node *);
 388         struct tnode *tn = tnode_alloc(sz);
 389
 390         if (tn)  {
 391                 memset(tn, 0, sz);
 392                 NODE_INIT_PARENT(tn, T_TNODE);
 393                 tn->pos = pos;
 394                 tn->bits = bits;
 395                 tn->key = key;
 396                 tn->full_children = 0;
 397                 tn->empty_children = 1<<bits;
 398         }
 399
 400         if (trie_debug > 0)
 401                 printk("AT %p s=%u %u\n", tn, (unsigned int) sizeof(struct tnode),
 402                        (unsigned int) (sizeof(struct node) * 1<<bits));
 403         return tn;
 404 }
 405
 406 static void tnode_free(struct tnode *tn)
 407 {
 408         if (!tn) {
 409                 trie_bug("tnode_free\n");
 410         }
 411         if (IS_LEAF(tn)) {
 412                 free_leaf((struct leaf *)tn);
 413                 if (trie_debug > 0 )
 414                         printk("FL %p \n", tn);
 415         }
 416         else if (IS_TNODE(tn)) {
 417                 __tnode_free(tn);
 418                 if (trie_debug > 0 )
 419                         printk("FT %p \n", tn);
 420         }
 421         else {
 422                 trie_bug("tnode_free\n");
 423         }
 424 }
 425
 426 /*
 427  * Check whether a tnode 'n' is "full", i.e. it is an internal node
 428  * and no bits are skipped. See discussion in dyntree paper p. 6
 429  */
 430
 431 static inline int tnode_full(struct tnode *tn, struct node *n)
 432 {
 433         if (n == NULL || IS_LEAF(n))
 434                 return 0;
 435
 436         return ((struct tnode *) n)->pos == tn->pos + tn->bits;
 437 }
 438
 439 static inline void put_child(struct trie *t, struct tnode *tn, int i, struct node *n)
 440 {
 441         tnode_put_child_reorg(tn, i, n, -1);
 442 }
 443
 444  /*
 445   * Add a child at position i overwriting the old value.
 446   * Update the value of full_children and empty_children.
 447   */
 448
 449 static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int wasfull)
 450 {
 451         struct node *chi;
 452         int isfull;
 453
 454         if (i >= 1<<tn->bits) {
 455                 printk("bits=%d, i=%d\n", tn->bits, i);
 456                 trie_bug("tnode_put_child_reorg bits");
 457         }
 458         write_lock_bh(&fib_lock);
 459         chi = tn->child[i];
 460
 461         /* update emptyChildren */
 462         if (n == NULL && chi != NULL)
 463                 tn->empty_children++;
 464         else if (n != NULL && chi == NULL)
 465                 tn->empty_children--;
 466
 467         /* update fullChildren */
 468         if (wasfull == -1)
 469                 wasfull = tnode_full(tn, chi);
 470
 471         isfull = tnode_full(tn, n);
 472         if (wasfull && !isfull)
 473                 tn->full_children--;
 474
 475         else if (!wasfull && isfull)
 476                 tn->full_children++;
 477         if (n)
 478                 NODE_SET_PARENT(n, tn);
 479
 480         tn->child[i] = n;
 481         write_unlock_bh(&fib_lock);
 482 }
 483
 484 static struct node *resize(struct trie *t, struct tnode *tn)
 485 {
 486         int i;
 487         int err = 0;
 488
 489         if (!tn)
 490                 return NULL;
 491
 492         if (trie_debug)
 493                 printk("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
 494                       tn, inflate_threshold, halve_threshold);
 495
 496         /* No children */
 497         if (tn->empty_children == tnode_child_length(tn)) {
 498                 tnode_free(tn);
 499                 return NULL;
 500         }
 501         /* One child */
 502         if (tn->empty_children == tnode_child_length(tn) - 1)
 503                 for (i = 0; i < tnode_child_length(tn); i++) {
 504
 505                         write_lock_bh(&fib_lock);
 506                         if (tn->child[i] != NULL) {
 507
 508                                 /* compress one level */
 509                                 struct node *n = tn->child[i];
 510                                 if (n)
 511                                         NODE_INIT_PARENT(n, NODE_TYPE(n));
 512
 513                                 write_unlock_bh(&fib_lock);
 514                                 tnode_free(tn);
 515                                 return n;
 516                         }
 517                         write_unlock_bh(&fib_lock);
 518                 }
 519         /*
 520          * Double as long as the resulting node has a number of
 521          * nonempty nodes that are above the threshold.
 522          */
 523
 524         /*
 525          * From "Implementing a dynamic compressed trie" by Stefan Nilsson of
 526          * the Helsinki University of Technology and Matti Tikkanen of Nokia
 527          * Telecommunications, page 6:
 528          * "A node is doubled if the ratio of non-empty children to all
 529          * children in the *doubled* node is at least 'high'."
 530          *
 531          * 'high' in this instance is the variable 'inflate_threshold'. It
 532          * is expressed as a percentage, so we multiply it with
 533          * tnode_child_length() and instead of multiplying by 2 (since the
 534          * child array will be doubled by inflate()) and multiplying
 535          * the left-hand side by 100 (to handle the percentage thing) we
 536          * multiply the left-hand side by 50.
 537          *
 538          * The left-hand side may look a bit weird: tnode_child_length(tn)
 539          * - tn->empty_children is of course the number of non-null children
 540          * in the current node. tn->full_children is the number of "full"
 541          * children, that is non-null tnodes with a skip value of 0.
 542          * All of those will be doubled in the resulting inflated tnode, so
 543          * we just count them one extra time here.
 544          *
 545          * A clearer way to write this would be:
 546          *
 547          * to_be_doubled = tn->full_children;
 548          * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
 549          *     tn->full_children;
 550          *
 551          * new_child_length = tnode_child_length(tn) * 2;
 552          *
 553          * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
 554          *      new_child_length;
 555          * if (new_fill_factor >= inflate_threshold)
 556          *
 557          * ...and so on, tho it would mess up the while () loop.
 558          *
 559          * anyway,
 560          * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
 561          *      inflate_threshold
 562          *
 563          * avoid a division:
 564          * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
 565          *      inflate_threshold * new_child_length
 566          *
 567          * expand not_to_be_doubled and to_be_doubled, and shorten:
 568          * 100 * (tnode_child_length(tn) - tn->empty_children +
 569          *    tn->full_children ) >= inflate_threshold * new_child_length
 570          *
 571          * expand new_child_length:
 572          * 100 * (tnode_child_length(tn) - tn->empty_children +
 573          *    tn->full_children ) >=
 574          *      inflate_threshold * tnode_child_length(tn) * 2
 575          *
 576          * shorten again:
 577          * 50 * (tn->full_children + tnode_child_length(tn) -
 578          *    tn->empty_children ) >= inflate_threshold *
 579          *    tnode_child_length(tn)
 580          *
 581          */
 582
 583         check_tnode(tn);
 584
 585         err = 0;
 586         while ((tn->full_children > 0 &&
 587                50 * (tn->full_children + tnode_child_length(tn) - tn->empty_children) >=
 588                                 inflate_threshold * tnode_child_length(tn))) {
 589
 590                 tn = inflate(t, tn, &err);
 591
 592                 if (err) {
 593 #ifdef CONFIG_IP_FIB_TRIE_STATS
 594                         t->stats.resize_node_skipped++;
 595 #endif
 596                         break;
 597                 }
 598         }
 599
 600         check_tnode(tn);
 601
 602         /*
 603          * Halve as long as the number of empty children in this
 604          * node is above threshold.
 605          */
 606
 607         err = 0;
 608         while (tn->bits > 1 &&
 609                100 * (tnode_child_length(tn) - tn->empty_children) <
 610                halve_threshold * tnode_child_length(tn)) {
 611
 612                 tn = halve(t, tn, &err);
 613
 614                 if (err) {
 615 #ifdef CONFIG_IP_FIB_TRIE_STATS
 616                         t->stats.resize_node_skipped++;
 617 #endif
 618                         break;
 619                 }
 620         }
 621
 622
 623         /* Only one child remains */
 624
 625         if (tn->empty_children == tnode_child_length(tn) - 1)
 626                 for (i = 0; i < tnode_child_length(tn); i++) {
 627
 628                         write_lock_bh(&fib_lock);
 629                         if (tn->child[i] != NULL) {
 630                                 /* compress one level */
 631                                 struct node *n = tn->child[i];
 632
 633                                 if (n)
 634                                         NODE_INIT_PARENT(n, NODE_TYPE(n));
 635
 636                                 write_unlock_bh(&fib_lock);
 637                                 tnode_free(tn);
 638                                 return n;
 639                         }
 640                         write_unlock_bh(&fib_lock);
 641                 }
 642
 643         return (struct node *) tn;
 644 }
 645
 646 static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err)
 647 {
 648         struct tnode *inode;
 649         struct tnode *oldtnode = tn;
 650         int olen = tnode_child_length(tn);
 651         int i;
 652
 653         if (trie_debug)
 654                 printk("In inflate\n");
 655
 656         tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits + 1);
 657
 658         if (!tn) {
 659                 *err = -ENOMEM;
 660                 return oldtnode;
 661         }
 662
 663         /*
 664          * Preallocate and store tnodes before the actual work so we
 665          * don't get into an inconsistent state if memory allocation
 666          * fails. In case of failure we return the oldnode and  inflate
 667          * of tnode is ignored.
 668          */
 669
 670         for(i = 0; i < olen; i++) {
 671                 struct tnode *inode = (struct tnode *) tnode_get_child(oldtnode, i);
 672
 673                 if (inode &&
 674                     IS_TNODE(inode) &&
 675                     inode->pos == oldtnode->pos + oldtnode->bits &&
 676                     inode->bits > 1) {
 677                         struct tnode *left, *right;
 678
 679                         t_key m = TKEY_GET_MASK(inode->pos, 1);
 680
 681                         left = tnode_new(inode->key&(~m), inode->pos + 1,
 682                                          inode->bits - 1);
 683
 684                         if (!left) {
 685                                 *err = -ENOMEM;
 686                                 break;
 687                         }
 688
 689                         right = tnode_new(inode->key|m, inode->pos + 1,
 690                                           inode->bits - 1);
 691
 692                         if (!right) {
 693                                 *err = -ENOMEM;
 694                                 break;
 695                         }
 696
 697                         put_child(t, tn, 2*i, (struct node *) left);
 698                         put_child(t, tn, 2*i+1, (struct node *) right);
 699                 }
 700         }
 701
 702         if (*err) {
 703                 int size = tnode_child_length(tn);
 704                 int j;
 705
 706                 for(j = 0; j < size; j++)
 707                         if (tn->child[j])
 708                                 tnode_free((struct tnode *)tn->child[j]);
 709
 710                 tnode_free(tn);
 711
 712                 *err = -ENOMEM;
 713                 return oldtnode;
 714         }
 715
 716         for(i = 0; i < olen; i++) {
 717                 struct node *node = tnode_get_child(oldtnode, i);
 718
 719                 /* An empty child */
 720                 if (node == NULL)
 721                         continue;
 722
 723                 /* A leaf or an internal node with skipped bits */
 724
 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                                              1) == 0)
 729                                 put_child(t, tn, 2*i, node);
 730                         else
 731                                 put_child(t, tn, 2*i+1, node);
 732                         continue;
 733                 }
 734
 735                 /* An internal node with two children */
 736                 inode = (struct tnode *) node;
 737
 738                 if (inode->bits == 1) {
 739                         put_child(t, tn, 2*i, inode->child[0]);
 740                         put_child(t, tn, 2*i+1, inode->child[1]);
 741
 742                         tnode_free(inode);
 743                 }
 744
 745                         /* An internal node with more than two children */
 746                 else {
 747                         struct tnode *left, *right;
 748                         int size, j;
 749
 750                         /* We will replace this node 'inode' with two new
 751                          * ones, 'left' and 'right', each with half of the
 752                          * original children. The two new nodes will have
 753                          * a position one bit further down the key and this
 754                          * means that the "significant" part of their keys
 755                          * (see the discussion near the top of this file)
 756                          * will differ by one bit, which will be "0" in
 757                          * left's key and "1" in right's key. Since we are
 758                          * moving the key position by one step, the bit that
 759                          * we are moving away from - the bit at position
 760                          * (inode->pos) - is the one that will differ between
 761                          * left and right. So... we synthesize that bit in the
 762                          * two  new keys.
 763                          * The mask 'm' below will be a single "one" bit at
 764                          * the position (inode->pos)
 765                          */
 766
 767                         /* Use the old key, but set the new significant
 768                          *   bit to zero.
 769                          */
 770
 771                         left = (struct tnode *) tnode_get_child(tn, 2*i);
 772                         put_child(t, tn, 2*i, NULL);
 773
 774                         if (!left)
 775                                 BUG();
 776
 777                         right = (struct tnode *) tnode_get_child(tn, 2*i+1);
 778                         put_child(t, tn, 2*i+1, NULL);
 779
 780                         if (!right)
 781                                 BUG();
 782
 783                         size = tnode_child_length(left);
 784                         for(j = 0; j < size; j++) {
 785                                 put_child(t, left, j, inode->child[j]);
 786                                 put_child(t, right, j, inode->child[j + size]);
 787                         }
 788                         put_child(t, tn, 2*i, resize(t, left));
 789                         put_child(t, tn, 2*i+1, resize(t, right));
 790
 791                         tnode_free(inode);
 792                 }
 793         }
 794         tnode_free(oldtnode);
 795         return tn;
 796 }
 797
 798 static struct tnode *halve(struct trie *t, struct tnode *tn, int *err)
 799 {
 800         struct tnode *oldtnode = tn;
 801         struct node *left, *right;
 802         int i;
 803         int olen = tnode_child_length(tn);
 804
 805         if (trie_debug) printk("In halve\n");
 806
 807         tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits - 1);
 808
 809         if (!tn) {
 810                 *err = -ENOMEM;
 811                 return oldtnode;
 812         }
 813
 814         /*
 815          * Preallocate and store tnodes before the actual work so we
 816          * don't get into an inconsistent state if memory allocation
 817          * fails. In case of failure we return the oldnode and halve
 818          * of tnode is ignored.
 819          */
 820
 821         for(i = 0; i < olen; i += 2) {
 822                 left = tnode_get_child(oldtnode, i);
 823                 right = tnode_get_child(oldtnode, i+1);
 824
 825                 /* Two nonempty children */
 826                 if (left && right)  {
 827                         struct tnode *newBinNode =
 828                                 tnode_new(left->key, tn->pos + tn->bits, 1);
 829
 830                         if (!newBinNode) {
 831                                 *err = -ENOMEM;
 832                                 break;
 833                         }
 834                         put_child(t, tn, i/2, (struct node *)newBinNode);
 835                 }
 836         }
 837
 838         if (*err) {
 839                 int size = tnode_child_length(tn);
 840                 int j;
 841
 842                 for(j = 0; j < size; j++)
 843                         if (tn->child[j])
 844                                 tnode_free((struct tnode *)tn->child[j]);
 845
 846                 tnode_free(tn);
 847
 848                 *err = -ENOMEM;
 849                 return oldtnode;
 850         }
 851
 852         for(i = 0; i < olen; i += 2) {
 853                 left = tnode_get_child(oldtnode, i);
 854                 right = tnode_get_child(oldtnode, i+1);
 855
 856                 /* At least one of the children is empty */
 857                 if (left == NULL) {
 858                         if (right == NULL)    /* Both are empty */
 859                                 continue;
 860                         put_child(t, tn, i/2, right);
 861                 } else if (right == NULL)
 862                         put_child(t, tn, i/2, left);
 863
 864                 /* Two nonempty children */
 865                 else {
 866                         struct tnode *newBinNode =
 867                                 (struct tnode *) tnode_get_child(tn, i/2);
 868                         put_child(t, tn, i/2, NULL);
 869
 870                         if (!newBinNode)
 871                                 BUG();
 872
 873                         put_child(t, newBinNode, 0, left);
 874                         put_child(t, newBinNode, 1, right);
 875                         put_child(t, tn, i/2, resize(t, newBinNode));
 876                 }
 877         }
 878         tnode_free(oldtnode);
 879         return tn;
 880 }
 881
 882 static void *trie_init(struct trie *t)
 883 {
 884         if (t) {
 885                 t->size = 0;
 886                 t->trie = NULL;
 887                 t->revision = 0;
 888 #ifdef CONFIG_IP_FIB_TRIE_STATS
 889                 memset(&t->stats, 0, sizeof(struct trie_use_stats));
 890 #endif
 891         }
 892         return t;
 893 }
 894
 895 static struct leaf_info *find_leaf_info(struct hlist_head *head, int plen)
 896 {
 897         struct hlist_node *node;
 898         struct leaf_info *li;
 899
 900         hlist_for_each_entry(li, node, head, hlist) {
 901                 if (li->plen == plen)
 902                         return li;
 903         }
 904         return NULL;
 905 }
 906
 907 static inline struct list_head * get_fa_head(struct leaf *l, int plen)
 908 {
 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         return fa_head;
 916 }
 917
 918 static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
 919 {
 920         struct leaf_info *li = NULL, *last = NULL;
 921         struct hlist_node *node, *tmp;
 922
 923         write_lock_bh(&fib_lock);
 924
 925         if (hlist_empty(head))
 926                 hlist_add_head(&new->hlist, head);
 927         else {
 928                 hlist_for_each_entry_safe(li, node, tmp, head, hlist) {
 929
 930                         if (new->plen > li->plen)
 931                                 break;
 932
 933                         last = li;
 934                 }
 935                 if (last)
 936                         hlist_add_after(&last->hlist, &new->hlist);
 937                 else
 938                         hlist_add_before(&new->hlist, &li->hlist);
 939         }
 940         write_unlock_bh(&fib_lock);
 941 }
 942
 943 static struct leaf *
 944 fib_find_node(struct trie *t, u32 key)
 945 {
 946         int pos;
 947         struct tnode *tn;
 948         struct node *n;
 949
 950         pos = 0;
 951         n = t->trie;
 952
 953         while (n != NULL &&  NODE_TYPE(n) == T_TNODE) {
 954                 tn = (struct tnode *) n;
 955
 956                 check_tnode(tn);
 957
 958                 if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
 959                         pos=tn->pos + tn->bits;
 960                         n = tnode_get_child(tn, tkey_extract_bits(key, tn->pos, tn->bits));
 961                 }
 962                 else
 963                         break;
 964         }
 965         /* Case we have found a leaf. Compare prefixes */
 966
 967         if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key)) {
 968                 struct leaf *l = (struct leaf *) n;
 969                 return l;
 970         }
 971         return NULL;
 972 }
 973
 974 static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
 975 {
 976         int i = 0;
 977         int wasfull;
 978         t_key cindex, key;
 979         struct tnode *tp = NULL;
 980
 981         if (!tn)
 982                 BUG();
 983
 984         key = tn->key;
 985         i = 0;
 986
 987         while (tn != NULL && NODE_PARENT(tn) != NULL) {
 988
 989                 if (i > 10) {
 990                         printk("Rebalance tn=%p \n", tn);
 991                         if (tn)                 printk("tn->parent=%p \n", NODE_PARENT(tn));
 992
 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                 i++;
 999
1000                 tp = NODE_PARENT(tn);
1001                 cindex = tkey_extract_bits(key, tp->pos, tp->bits);
1002                 wasfull = tnode_full(tp, tnode_get_child(tp, cindex));
1003                 tn = (struct tnode *) resize (t, (struct tnode *)tn);
1004                 tnode_put_child_reorg((struct tnode *)tp, cindex,(struct node*)tn, wasfull);
1005
1006                 if (!NODE_PARENT(tn))
1007                         break;
1008
1009                 tn = NODE_PARENT(tn);
1010         }
1011         /* Handle last (top) tnode */
1012         if (IS_TNODE(tn))
1013                 tn = (struct tnode*) resize(t, (struct tnode *)tn);
1014
1015         return (struct node*) tn;
1016 }
1017
1018 static  struct list_head *
1019 fib_insert_node(struct trie *t, int *err, u32 key, int plen)
1020 {
1021         int pos, newpos;
1022         struct tnode *tp = NULL, *tn = NULL;
1023         struct node *n;
1024         struct leaf *l;
1025         int missbit;
1026         struct list_head *fa_head = NULL;
1027         struct leaf_info *li;
1028         t_key cindex;
1029
1030         pos = 0;
1031         n = t->trie;
1032
1033         /* If we point to NULL, stop. Either the tree is empty and we should
1034          * 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          * If we point to a T_TNODE, check if it matches our key. Note that
1037          * a T_TNODE might be skipping any number of bits - its 'pos' need
1038          * not be the parent's 'pos'+'bits'!
1039          *
1040          * If it does match the current key, get pos/bits from it, extract
1041          * the index from our key, push the T_TNODE and walk the tree.
1042          *
1043          * If it doesn't, we have to replace it with a new T_TNODE.
1044          *
1045          * If we point to a T_LEAF, it might or might not have the same key
1046          * as we do. If it does, just change the value, update the T_LEAF's
1047          * value, and return it.
1048          * If it doesn't, we need to replace it with a T_TNODE.
1049          */
1050
1051         while (n != NULL &&  NODE_TYPE(n) == T_TNODE) {
1052                 tn = (struct tnode *) n;
1053
1054                 check_tnode(tn);
1055
1056                 if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
1057                         tp = tn;
1058                         pos=tn->pos + tn->bits;
1059                         n = tnode_get_child(tn, tkey_extract_bits(key, tn->pos, tn->bits));
1060
1061                         if (n && NODE_PARENT(n) != tn) {
1062                                 printk("BUG tn=%p, n->parent=%p\n", tn, NODE_PARENT(n));
1063                                 BUG();
1064                         }
1065                 }
1066                 else
1067                         break;
1068         }
1069
1070         /*
1071          * n  ----> NULL, LEAF or TNODE
1072          *
1073          * tp is n's (parent) ----> NULL or TNODE
1074          */
1075
1076         if (tp && IS_LEAF(tp))
1077                 BUG();
1078
1079
1080         /* Case 1: n is a leaf. Compare prefixes */
1081
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                         *err = -ENOMEM;
1089                         goto err;
1090                 }
1091
1092                 fa_head = &li->falh;
1093                 insert_leaf_info(&l->list, li);
1094                 goto done;
1095         }
1096         t->size++;
1097         l = leaf_new();
1098
1099         if (!l) {
1100                 *err = -ENOMEM;
1101                 goto err;
1102         }
1103
1104         l->key = key;
1105         li = leaf_info_new(plen);
1106
1107         if (!li) {
1108                 tnode_free((struct tnode *) l);
1109                 *err = -ENOMEM;
1110                 goto err;
1111         }
1112
1113         fa_head = &li->falh;
1114         insert_leaf_info(&l->list, li);
1115
1116         /* Case 2: n is NULL, and will just insert a new leaf */
1117         if (t->trie && n == NULL) {
1118
1119                 NODE_SET_PARENT(l, tp);
1120
1121                 if (!tp)
1122                         BUG();
1123
1124                 else {
1125                         cindex = tkey_extract_bits(key, tp->pos, tp->bits);
1126                         put_child(t, (struct tnode *)tp, cindex, (struct node *)l);
1127                 }
1128         }
1129         /* Case 3: n is a LEAF or a TNODE and the key doesn't match. */
1130         else {
1131                 /*
1132                  *  Add a new tnode here
1133                  *  first tnode need some special handling
1134                  */
1135
1136                 if (tp)
1137                         pos=tp->pos+tp->bits;
1138                 else
1139                         pos=0;
1140                 if (n) {
1141                         newpos = tkey_mismatch(key, pos, n->key);
1142                         tn = tnode_new(n->key, newpos, 1);
1143                 }
1144                 else {
1145                         newpos = 0;
1146                         tn = tnode_new(key, newpos, 1); /* First tnode */
1147                 }
1148
1149                 if (!tn) {
1150                         free_leaf_info(li);
1151                         tnode_free((struct tnode *) l);
1152                         *err = -ENOMEM;
1153                         goto err;
1154                 }
1155
1156                 NODE_SET_PARENT(tn, tp);
1157
1158                 missbit=tkey_extract_bits(key, newpos, 1);
1159                 put_child(t, tn, missbit, (struct node *)l);
1160                 put_child(t, tn, 1-missbit, n);
1161
1162                 if (tp) {
1163                         cindex = tkey_extract_bits(key, tp->pos, tp->bits);
1164                         put_child(t, (struct tnode *)tp, cindex, (struct node *)tn);
1165                 }
1166                 else {
1167                         t->trie = (struct node*) tn; /* First tnode */
1168                         tp = tn;
1169                 }
1170         }
1171         if (tp && tp->pos+tp->bits > 32) {
1172                 printk("ERROR tp=%p pos=%d, bits=%d, key=%0x plen=%d\n",
1173                        tp, tp->pos, tp->bits, key, plen);
1174         }
1175         /* Rebalance the trie */
1176         t->trie = trie_rebalance(t, tp);
1177 done:
1178         t->revision++;
1179 err:;
1180         return fa_head;
1181 }
1182
1183 static int
1184 fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
1185                struct nlmsghdr *nlhdr, struct netlink_skb_parms *req)
1186 {
1187         struct trie *t = (struct trie *) tb->tb_data;
1188         struct fib_alias *fa, *new_fa;
1189         struct list_head *fa_head = NULL;
1190         struct fib_info *fi;
1191         int plen = r->rtm_dst_len;
1192         int type = r->rtm_type;
1193         u8 tos = r->rtm_tos;
1194         u32 key, mask;
1195         int err;
1196         struct leaf *l;
1197
1198         if (plen > 32)
1199                 return -EINVAL;
1200
1201         key = 0;
1202         if (rta->rta_dst)
1203                 memcpy(&key, rta->rta_dst, 4);
1204
1205         key = ntohl(key);
1206
1207         if (trie_debug)
1208                 printk("Insert table=%d %08x/%d\n", tb->tb_id, key, plen);
1209
1210         mask = ntohl( inet_make_mask(plen) );
1211
1212         if (key & ~mask)
1213                 return -EINVAL;
1214
1215         key = key & mask;
1216
1217         if  ((fi = fib_create_info(r, rta, nlhdr, &err)) == NULL)
1218                 goto err;
1219
1220         l = fib_find_node(t, key);
1221         fa = NULL;
1222
1223         if (l) {
1224                 fa_head = get_fa_head(l, plen);
1225                 fa = fib_find_alias(fa_head, tos, fi->fib_priority);
1226         }
1227
1228         /* Now fa, if non-NULL, points to the first fib alias
1229          * with the same keys [prefix,tos,priority], if such key already
1230          * exists or to the node before which we will insert new one.
1231          *
1232          * If fa is NULL, we will need to allocate a new one and
1233          * insert to the head of f.
1234          *
1235          * If f is NULL, no fib node matched the destination key
1236          * and we need to allocate a new one of those as well.
1237          */
1238
1239         if (fa &&
1240             fa->fa_info->fib_priority == fi->fib_priority) {
1241                 struct fib_alias *fa_orig;
1242
1243                 err = -EEXIST;
1244                 if (nlhdr->nlmsg_flags & NLM_F_EXCL)
1245                         goto out;
1246
1247                 if (nlhdr->nlmsg_flags & NLM_F_REPLACE) {
1248                         struct fib_info *fi_drop;
1249                         u8 state;
1250
1251                         write_lock_bh(&fib_lock);
1252
1253                         fi_drop = fa->fa_info;
1254                         fa->fa_info = fi;
1255                         fa->fa_type = type;
1256                         fa->fa_scope = r->rtm_scope;
1257                         state = fa->fa_state;
1258                         fa->fa_state &= ~FA_S_ACCESSED;
1259
1260                         write_unlock_bh(&fib_lock);
1261
1262                         fib_release_info(fi_drop);
1263                         if (state & FA_S_ACCESSED)
1264                           rt_cache_flush(-1);
1265
1266                             goto succeeded;
1267                 }
1268                 /* Error if we find a perfect match which
1269                  * uses the same scope, type, and nexthop
1270                  * information.
1271                  */
1272                 fa_orig = fa;
1273                 list_for_each_entry(fa, fa_orig->fa_list.prev, fa_list) {
1274                         if (fa->fa_tos != tos)
1275                                 break;
1276                         if (fa->fa_info->fib_priority != fi->fib_priority)
1277                                 break;
1278                         if (fa->fa_type == type &&
1279                             fa->fa_scope == r->rtm_scope &&
1280                             fa->fa_info == fi) {
1281                                 goto out;
1282                         }
1283                 }
1284                 if (!(nlhdr->nlmsg_flags & NLM_F_APPEND))
1285                         fa = fa_orig;
1286         }
1287         err = -ENOENT;
1288         if (!(nlhdr->nlmsg_flags&NLM_F_CREATE))
1289                 goto out;
1290
1291         err = -ENOBUFS;
1292         new_fa = kmem_cache_alloc(fn_alias_kmem, SLAB_KERNEL);
1293         if (new_fa == NULL)
1294                 goto out;
1295
1296         new_fa->fa_info = fi;
1297         new_fa->fa_tos = tos;
1298         new_fa->fa_type = type;
1299         new_fa->fa_scope = r->rtm_scope;
1300         new_fa->fa_state = 0;
1301 #if 0
1302         new_fa->dst = NULL;
1303 #endif
1304         /*
1305          * Insert new entry to the list.
1306          */
1307
1308         if (!fa_head) {
1309                 fa_head = fib_insert_node(t, &err, key, plen);
1310                 err = 0;
1311                 if (err)
1312                         goto out_free_new_fa;
1313         }
1314
1315         write_lock_bh(&fib_lock);
1316
1317         list_add_tail(&new_fa->fa_list,
1318                  (fa ? &fa->fa_list : fa_head));
1319
1320         write_unlock_bh(&fib_lock);
1321
1322         rt_cache_flush(-1);
1323         rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id, nlhdr, req);
1324 succeeded:
1325         return 0;
1326
1327 out_free_new_fa:
1328         kmem_cache_free(fn_alias_kmem, new_fa);
1329 out:
1330         fib_release_info(fi);
1331 err:;
1332         return err;
1333 }
1334
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, int *err)
1337 {
1338         int i;
1339         t_key mask;
1340         struct leaf_info *li;
1341         struct hlist_head *hhead = &l->list;
1342         struct hlist_node *node;
1343
1344         hlist_for_each_entry(li, node, hhead, hlist) {
1345
1346                 i = li->plen;
1347                 mask = ntohl(inet_make_mask(i));
1348                 if (l->key != (key & mask))
1349                         continue;
1350
1351                 if (((*err) = fib_semantic_match(&li->falh, flp, res, l->key, mask, i)) == 0) {
1352                         *plen = i;
1353 #ifdef CONFIG_IP_FIB_TRIE_STATS
1354                         t->stats.semantic_match_passed++;
1355 #endif
1356                         return 1;
1357                 }
1358 #ifdef CONFIG_IP_FIB_TRIE_STATS
1359                 t->stats.semantic_match_miss++;
1360 #endif
1361         }
1362         return 0;
1363 }
1364
1365 static int
1366 fn_trie_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
1367 {
1368         struct trie *t = (struct trie *) tb->tb_data;
1369         int plen, ret = 0;
1370         struct node *n;
1371         struct tnode *pn;
1372         int pos, bits;
1373         t_key key=ntohl(flp->fl4_dst);
1374         int chopped_off;
1375         t_key cindex = 0;
1376         int current_prefix_length = KEYLENGTH;
1377         n = t->trie;
1378
1379         read_lock(&fib_lock);
1380         if (!n)
1381                 goto failed;
1382
1383 #ifdef CONFIG_IP_FIB_TRIE_STATS
1384         t->stats.gets++;
1385 #endif
1386
1387         /* Just a leaf? */
1388         if (IS_LEAF(n)) {
1389                 if (check_leaf(t, (struct leaf *)n, key, &plen, flp, res, &ret))
1390                         goto found;
1391                 goto failed;
1392         }
1393         pn = (struct tnode *) n;
1394         chopped_off = 0;
1395
1396         while (pn) {
1397
1398                 pos = pn->pos;
1399                 bits = pn->bits;
1400
1401                 if (!chopped_off)
1402                         cindex = tkey_extract_bits(MASK_PFX(key, current_prefix_length), pos, bits);
1403
1404                 n = tnode_get_child(pn, cindex);
1405
1406                 if (n == NULL) {
1407 #ifdef CONFIG_IP_FIB_TRIE_STATS
1408                         t->stats.null_node_hit++;
1409 #endif
1410                         goto backtrace;
1411                 }
1412
1413                 if (IS_TNODE(n)) {
1414 #define HL_OPTIMIZE
1415 #ifdef HL_OPTIMIZE
1416                         struct tnode *cn = (struct tnode *)n;
1417                         t_key node_prefix, key_prefix, pref_mismatch;
1418                         int mp;
1419
1420                         /*
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                          * This tnode is in the parent's child array at index
1424                          * key[p_pos..p_pos+p_bits] but potentially with some bits
1425                          * chopped off, so in reality the index may be just a
1426                          * subprefix, padded with zero at the end.
1427                          * We can also take a look at any skipped bits in this
1428                          * 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                          * considered unknown.
1432                          *
1433                          * The skipped bits are key[pos+bits..cn->pos].
1434                          */
1435
1436                         /* If current_prefix_length < pos+bits, we are already doing
1437                          * actual prefix  matching, which means everything from
1438                          * pos+(bits-chopped_off) onward must be zero along some
1439                          * branch of this subtree - otherwise there is *no* valid
1440                          * prefix present. Here we can only check the skipped
1441                          * bits. Remember, since we have already indexed into the
1442                          * parent's child array, we know that the bits we chopped of
1443                          * *are* zero.
1444                          */
1445
1446                         /* NOTA BENE: CHECKING ONLY SKIPPED BITS FOR THE NEW NODE HERE */
1447
1448                         if (current_prefix_length < pos+bits) {
1449                                 if (tkey_extract_bits(cn->key, current_prefix_length,
1450                                                       cn->pos - current_prefix_length) != 0 ||
1451                                     !(cn->child[0]))
1452                                         goto backtrace;
1453                         }
1454
1455                         /*
1456                          * If chopped_off=0, the index is fully validated and we
1457                          * only need to look at the skipped bits for this, the new,
1458                          * tnode. What we actually want to do is to find out if
1459                          * these skipped bits match our key perfectly, or if we will
1460                          * have to count on finding a matching prefix further down,
1461                          * because if we do, we would like to have some way of
1462                          * verifying the existence of such a prefix at this point.
1463                          */
1464
1465                         /* The only thing we can do at this point is to verify that
1466                          * any such matching prefix can indeed be a prefix to our
1467                          * key, and if the bits in the node we are inspecting that
1468                          * do not match our key are not ZERO, this cannot be true.
1469                          * Thus, find out where there is a mismatch (before cn->pos)
1470                          * and verify that all the mismatching bits are zero in the
1471                          * new tnode's key.
1472                          */
1473
1474                         /* Note: We aren't very concerned about the piece of the key
1475                          * that precede pn->pos+pn->bits, since these have already been
1476                          * checked. The bits after cn->pos aren't checked since these are
1477                          * by definition "unknown" at this point. Thus, what we want to
1478                          * see is if we are about to enter the "prefix matching" state,
1479                          * and in that case verify that the skipped bits that will prevail
1480                          * throughout this subtree are zero, as they have to be if we are
1481                          * to find a matching prefix.
1482                          */
1483
1484                         node_prefix = MASK_PFX(cn->key, cn->pos);
1485                         key_prefix = MASK_PFX(key, cn->pos);
1486                         pref_mismatch = key_prefix^node_prefix;
1487                         mp = 0;
1488
1489                         /* In short: If skipped bits in this node do not match the search
1490                          * key, enter the "prefix matching" state.directly.
1491                          */
1492                         if (pref_mismatch) {
1493                                 while (!(pref_mismatch & (1<<(KEYLENGTH-1)))) {
1494                                         mp++;
1495                                         pref_mismatch = pref_mismatch <<1;
1496                                 }
1497                                 key_prefix = tkey_extract_bits(cn->key, mp, cn->pos-mp);
1498
1499                                 if (key_prefix != 0)
1500                                         goto backtrace;
1501
1502                                 if (current_prefix_length >= cn->pos)
1503                                         current_prefix_length=mp;
1504                        }
1505 #endif
1506                        pn = (struct tnode *)n; /* Descend */
1507                        chopped_off = 0;
1508                        continue;
1509                 }
1510                 if (IS_LEAF(n)) {
1511                         if (check_leaf(t, (struct leaf *)n, key, &plen, flp, res, &ret))
1512                                 goto found;
1513                }
1514 backtrace:
1515                 chopped_off++;
1516
1517                 /* As zero don't change the child key (cindex) */
1518                 while ((chopped_off <= pn->bits) && !(cindex & (1<<(chopped_off-1)))) {
1519                         chopped_off++;
1520                 }
1521
1522                 /* Decrease current_... with bits chopped off */
1523                 if (current_prefix_length > pn->pos + pn->bits - chopped_off)
1524                         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                  * chopped off all bits in this tnode walk up to our parent.
1529                  */
1530
1531                 if (chopped_off <= pn->bits)
1532                         cindex &= ~(1 << (chopped_off-1));
1533                 else {
1534                         if (NODE_PARENT(pn) == NULL)
1535                                 goto failed;
1536
1537                         /* Get Child's index */
1538                         cindex = tkey_extract_bits(pn->key, NODE_PARENT(pn)->pos, NODE_PARENT(pn)->bits);
1539                         pn = NODE_PARENT(pn);
1540                         chopped_off = 0;
1541
1542 #ifdef CONFIG_IP_FIB_TRIE_STATS
1543                         t->stats.backtrack++;
1544 #endif
1545                         goto backtrace;
1546                 }
1547         }
1548 failed:
1549         ret = 1;
1550 found:
1551         read_unlock(&fib_lock);
1552         return ret;
1553 }
1554
1555 static int trie_leaf_remove(struct trie *t, t_key key)
1556 {
1557         t_key cindex;
1558         struct tnode *tp = NULL;
1559         struct node *n = t->trie;
1560         struct leaf *l;
1561
1562         if (trie_debug)
1563                 printk("entering trie_leaf_remove(%p)\n", n);
1564
1565         /* 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          * T_LEAF may or may not match our key.
1568          */
1569
1570         while (n != NULL && IS_TNODE(n)) {
1571                 struct tnode *tn = (struct tnode *) n;
1572                 check_tnode(tn);
1573                 n = tnode_get_child(tn ,tkey_extract_bits(key, tn->pos, tn->bits));
1574
1575                         if (n && NODE_PARENT(n) != tn) {
1576                                 printk("BUG tn=%p, n->parent=%p\n", tn, NODE_PARENT(n));
1577                                 BUG();
1578                         }
1579         }
1580         l = (struct leaf *) n;
1581
1582         if (!n || !tkey_equals(l->key, key))
1583                 return 0;
1584
1585         /*
1586          * Key found.
1587          * Remove the leaf and rebalance the tree
1588          */
1589
1590         t->revision++;
1591         t->size--;
1592
1593         tp = NODE_PARENT(n);
1594         tnode_free((struct tnode *) n);
1595
1596         if (tp) {
1597                 cindex = tkey_extract_bits(key, tp->pos, tp->bits);
1598                 put_child(t, (struct tnode *)tp, cindex, NULL);
1599                 t->trie = trie_rebalance(t, tp);
1600         }
1601         else
1602                 t->trie = NULL;
1603
1604         return 1;
1605 }
1606
1607 static int
1608 fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
1609                struct nlmsghdr *nlhdr, struct netlink_skb_parms *req)
1610 {
1611         struct trie *t = (struct trie *) tb->tb_data;
1612         u32 key, mask;
1613         int plen = r->rtm_dst_len;
1614         u8 tos = r->rtm_tos;
1615         struct fib_alias *fa, *fa_to_delete;
1616         struct list_head *fa_head;
1617         struct leaf *l;
1618
1619         if (plen > 32)
1620                 return -EINVAL;
1621
1622         key = 0;
1623         if (rta->rta_dst)
1624                 memcpy(&key, rta->rta_dst, 4);
1625
1626         key = ntohl(key);
1627         mask = ntohl( inet_make_mask(plen) );
1628
1629         if (key & ~mask)
1630                 return -EINVAL;
1631
1632         key = key & mask;
1633         l = fib_find_node(t, key);
1634
1635         if (!l)
1636                 return -ESRCH;
1637
1638         fa_head = get_fa_head(l, plen);
1639         fa = fib_find_alias(fa_head, tos, 0);
1640
1641         if (!fa)
1642                 return -ESRCH;
1643
1644         if (trie_debug)
1645                 printk("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
1646
1647         fa_to_delete = NULL;
1648         fa_head = fa->fa_list.prev;
1649         list_for_each_entry(fa, fa_head, fa_list) {
1650                 struct fib_info *fi = fa->fa_info;
1651
1652                 if (fa->fa_tos != tos)
1653                         break;
1654
1655                 if ((!r->rtm_type ||
1656                      fa->fa_type == r->rtm_type) &&
1657                     (r->rtm_scope == RT_SCOPE_NOWHERE ||
1658                      fa->fa_scope == r->rtm_scope) &&
1659                     (!r->rtm_protocol ||
1660                      fi->fib_protocol == r->rtm_protocol) &&
1661                     fib_nh_match(r, nlhdr, rta, fi) == 0) {
1662                         fa_to_delete = fa;
1663                         break;
1664                 }
1665         }
1666
1667         if (fa_to_delete) {
1668                 int kill_li = 0;
1669                 struct leaf_info *li;
1670
1671                 fa = fa_to_delete;
1672                 rtmsg_fib(RTM_DELROUTE, htonl(key), fa, plen, tb->tb_id, nlhdr, req);
1673
1674                 l = fib_find_node(t, key);
1675                 li = find_leaf_info(&l->list, plen);
1676
1677                 write_lock_bh(&fib_lock);
1678
1679                 list_del(&fa->fa_list);
1680
1681                 if (list_empty(fa_head)) {
1682                         hlist_del(&li->hlist);
1683                         kill_li = 1;
1684                 }
1685                 write_unlock_bh(&fib_lock);
1686
1687                 if (kill_li)
1688                         free_leaf_info(li);
1689
1690                 if (hlist_empty(&l->list))
1691                         trie_leaf_remove(t, key);
1692
1693                 if (fa->fa_state & FA_S_ACCESSED)
1694                         rt_cache_flush(-1);
1695
1696                 fn_free_alias(fa);
1697                 return 0;
1698         }
1699         return -ESRCH;
1700 }
1701
1702 static int trie_flush_list(struct trie *t, struct list_head *head)
1703 {
1704         struct fib_alias *fa, *fa_node;
1705         int found = 0;
1706
1707         list_for_each_entry_safe(fa, fa_node, head, fa_list) {
1708                 struct fib_info *fi = fa->fa_info;
1709
1710                 if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
1711
1712                         write_lock_bh(&fib_lock);
1713                         list_del(&fa->fa_list);
1714                         write_unlock_bh(&fib_lock);
1715
1716                         fn_free_alias(fa);
1717                         found++;
1718                 }
1719         }
1720         return found;
1721 }
1722
1723 static int trie_flush_leaf(struct trie *t, struct leaf *l)
1724 {
1725         int found = 0;
1726         struct hlist_head *lih = &l->list;
1727         struct hlist_node *node, *tmp;
1728         struct leaf_info *li = NULL;
1729
1730         hlist_for_each_entry_safe(li, node, tmp, lih, hlist) {
1731
1732                 found += trie_flush_list(t, &li->falh);
1733
1734                 if (list_empty(&li->falh)) {
1735
1736                         write_lock_bh(&fib_lock);
1737                         hlist_del(&li->hlist);
1738                         write_unlock_bh(&fib_lock);
1739
1740                         free_leaf_info(li);
1741                 }
1742         }
1743         return found;
1744 }
1745
1746 static struct leaf *nextleaf(struct trie *t, struct leaf *thisleaf)
1747 {
1748         struct node *c = (struct node *) thisleaf;
1749         struct tnode *p;
1750         int idx;
1751
1752         if (c == NULL) {
1753                 if (t->trie == NULL)
1754                         return NULL;
1755
1756                 if (IS_LEAF(t->trie))          /* trie w. just a leaf */
1757                         return (struct leaf *) t->trie;
1758
1759                 p = (struct tnode*) t->trie;  /* Start */
1760         }
1761         else
1762                 p = (struct tnode *) NODE_PARENT(c);
1763
1764         while (p) {
1765                 int pos, last;
1766
1767                 /*  Find the next child of the parent */
1768                 if (c)
1769                         pos = 1 + tkey_extract_bits(c->key, p->pos, p->bits);
1770                 else
1771                         pos = 0;
1772
1773                 last = 1 << p->bits;
1774                 for(idx = pos; idx < last ; idx++) {
1775                         if (p->child[idx]) {
1776
1777                                 /* Decend if tnode */
1778
1779                                 while (IS_TNODE(p->child[idx])) {
1780                                         p = (struct tnode*) p->child[idx];
1781                                         idx = 0;
1782
1783                                         /* Rightmost non-NULL branch */
1784                                         if (p && IS_TNODE(p))
1785                                                 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                                                 goto up;
1790                                 }
1791                                 return (struct leaf*) p->child[idx];
1792                         }
1793                 }
1794 up:
1795                 /* No more children go up one step  */
1796                 c = (struct node*) p;
1797                 p = (struct tnode *) NODE_PARENT(p);
1798         }
1799         return NULL; /* Ready. Root of trie */
1800 }
1801
1802 static int fn_trie_flush(struct fib_table *tb)
1803 {
1804         struct trie *t = (struct trie *) tb->tb_data;
1805         struct leaf *ll = NULL, *l = NULL;
1806         int found = 0, h;
1807
1808         t->revision++;
1809
1810         for (h=0; (l = nextleaf(t, l)) != NULL; h++) {
1811                 found += trie_flush_leaf(t, l);
1812
1813                 if (ll && hlist_empty(&ll->list))
1814                         trie_leaf_remove(t, ll->key);
1815                 ll = l;
1816         }
1817
1818         if (ll && hlist_empty(&ll->list))
1819                 trie_leaf_remove(t, ll->key);
1820
1821         if (trie_debug)
1822                 printk("trie_flush found=%d\n", found);
1823         return found;
1824 }
1825
1826 static int trie_last_dflt=-1;
1827
1828 static void
1829 fn_trie_select_default(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
1830 {
1831         struct trie *t = (struct trie *) tb->tb_data;
1832         int order, last_idx;
1833         struct fib_info *fi = NULL;
1834         struct fib_info *last_resort;
1835         struct fib_alias *fa = NULL;
1836         struct list_head *fa_head;
1837         struct leaf *l;
1838
1839         last_idx = -1;
1840         last_resort = NULL;
1841         order = -1;
1842
1843         read_lock(&fib_lock);
1844
1845         l = fib_find_node(t, 0);
1846         if (!l)
1847                 goto out;
1848
1849         fa_head = get_fa_head(l, 0);
1850         if (!fa_head)
1851                 goto out;
1852
1853         if (list_empty(fa_head))
1854                 goto out;
1855
1856         list_for_each_entry(fa, fa_head, fa_list) {
1857                 struct fib_info *next_fi = fa->fa_info;
1858
1859                 if (fa->fa_scope != res->scope ||
1860                     fa->fa_type != RTN_UNICAST)
1861                         continue;
1862
1863                 if (next_fi->fib_priority > res->fi->fib_priority)
1864                         break;
1865                 if (!next_fi->fib_nh[0].nh_gw ||
1866                     next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
1867                         continue;
1868                 fa->fa_state |= FA_S_ACCESSED;
1869
1870                 if (fi == NULL) {
1871                         if (next_fi != res->fi)
1872                                 break;
1873                 } else if (!fib_detect_death(fi, order, &last_resort,
1874                                              &last_idx, &trie_last_dflt)) {
1875                         if (res->fi)
1876                                 fib_info_put(res->fi);
1877                         res->fi = fi;
1878                         atomic_inc(&fi->fib_clntref);
1879                         trie_last_dflt = order;
1880                         goto out;
1881                 }
1882                 fi = next_fi;
1883                 order++;
1884         }
1885         if (order <= 0 || fi == NULL) {
1886                 trie_last_dflt = -1;
1887                 goto out;
1888         }
1889
1890         if (!fib_detect_death(fi, order, &last_resort, &last_idx, &trie_last_dflt)) {
1891                 if (res->fi)
1892                         fib_info_put(res->fi);
1893                 res->fi = fi;
1894                 atomic_inc(&fi->fib_clntref);
1895                 trie_last_dflt = order;
1896                 goto out;
1897         }
1898         if (last_idx >= 0) {
1899                 if (res->fi)
1900                         fib_info_put(res->fi);
1901                 res->fi = last_resort;
1902                 if (last_resort)
1903                         atomic_inc(&last_resort->fib_clntref);
1904         }
1905         trie_last_dflt = last_idx;
1906  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                            struct sk_buff *skb, struct netlink_callback *cb)
1912 {
1913         int i, s_i;
1914         struct fib_alias *fa;
1915
1916         u32 xkey=htonl(key);
1917
1918         s_i=cb->args[3];
1919         i = 0;
1920
1921         list_for_each_entry(fa, fah, fa_list) {
1922                 if (i < s_i) {
1923                         i++;
1924                         continue;
1925                 }
1926                 if (fa->fa_info->fib_nh == NULL) {
1927                         printk("Trie error _fib_nh=NULL in fa[%d] k=%08x plen=%d\n", i, key, plen);
1928                         i++;
1929                         continue;
1930                 }
1931                 if (fa->fa_info == NULL) {
1932                         printk("Trie error fa_info=NULL in fa[%d] k=%08x plen=%d\n", i, key, plen);
1933                         i++;
1934                         continue;
1935                 }
1936
1937                 if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
1938                                   cb->nlh->nlmsg_seq,
1939                                   RTM_NEWROUTE,
1940                                   tb->tb_id,
1941                                   fa->fa_type,
1942                                   fa->fa_scope,
1943                                   &xkey,
1944                                   plen,
1945                                   fa->fa_tos,
1946                                   fa->fa_info, 0) < 0) {
1947                         cb->args[3] = i;
1948                         return -1;
1949                         }
1950                 i++;
1951         }
1952         cb->args[3]=i;
1953         return skb->len;
1954 }
1955
1956 static int fn_trie_dump_plen(struct trie *t, int plen, struct fib_table *tb, struct sk_buff *skb,
1957                              struct netlink_callback *cb)
1958 {
1959         int h, s_h;
1960         struct list_head *fa_head;
1961         struct leaf *l = NULL;
1962         s_h=cb->args[2];
1963
1964         for (h=0; (l = nextleaf(t, l)) != NULL; h++) {
1965
1966                 if (h < s_h)
1967                         continue;
1968                 if (h > s_h)
1969                         memset(&cb->args[3], 0,
1970                                sizeof(cb->args) - 3*sizeof(cb->args[0]));
1971
1972                 fa_head = get_fa_head(l, plen);
1973
1974                 if (!fa_head)
1975                         continue;
1976
1977                 if (list_empty(fa_head))
1978                         continue;
1979
1980                 if (fn_trie_dump_fa(l->key, plen, fa_head, tb, skb, cb)<0) {
1981                         cb->args[2]=h;
1982                         return -1;
1983                 }
1984         }
1985         cb->args[2]=h;
1986         return skb->len;
1987 }
1988
1989 static int fn_trie_dump(struct fib_table *tb, struct sk_buff *skb, struct netlink_callback *cb)
1990 {
1991         int m, s_m;
1992         struct trie *t = (struct trie *) tb->tb_data;
1993
1994         s_m = cb->args[1];
1995
1996         read_lock(&fib_lock);
1997         for (m=0; m<=32; m++) {
1998
1999                 if (m < s_m)
2000                         continue;
2001                 if (m > s_m)
2002                         memset(&cb->args[2], 0,
2003                                sizeof(cb->args) - 2*sizeof(cb->args[0]));
2004
2005                 if (fn_trie_dump_plen(t, 32-m, tb, skb, cb)<0) {
2006                         cb->args[1] = m;
2007                         goto out;
2008                 }
2009         }
2010         read_unlock(&fib_lock);
2011         cb->args[1] = m;
2012         return skb->len;
2013  out:
2014         read_unlock(&fib_lock);
2015         return -1;
2016 }
2017
2018 /* Fix more generic FIB names for init later */
2019
2020 #ifdef CONFIG_IP_MULTIPLE_TABLES
2021 struct fib_table * fib_hash_init(int id)
2022 #else
2023 struct fib_table * __init fib_hash_init(int id)
2024 #endif
2025 {
2026         struct fib_table *tb;
2027         struct trie *t;
2028
2029         if (fn_alias_kmem == NULL)
2030                 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
2031                                                   sizeof(struct fib_alias),
2032                                                   0, SLAB_HWCACHE_ALIGN,
2033                                                   NULL, NULL);
2034
2035         tb = kmalloc(sizeof(struct fib_table) + sizeof(struct trie),
2036                      GFP_KERNEL);
2037         if (tb == NULL)
2038                 return NULL;
2039
2040         tb->tb_id = id;
2041         tb->tb_lookup = fn_trie_lookup;
2042         tb->tb_insert = fn_trie_insert;
2043         tb->tb_delete = fn_trie_delete;
2044         tb->tb_flush = fn_trie_flush;
2045         tb->tb_select_default = fn_trie_select_default;
2046         tb->tb_dump = fn_trie_dump;
2047         memset(tb->tb_data, 0, sizeof(struct trie));
2048
2049         t = (struct trie *) tb->tb_data;
2050
2051         trie_init(t);
2052
2053         if (id == RT_TABLE_LOCAL)
2054                 trie_local = t;
2055         else if (id == RT_TABLE_MAIN)
2056                 trie_main = t;
2057
2058         if (id == RT_TABLE_LOCAL)
2059                 printk("IPv4 FIB: Using LC-trie version %s\n", VERSION);
2060
2061         return tb;
2062 }
2063
2064 /* Trie dump functions */
2065
2066 static void putspace_seq(struct seq_file *seq, int n)
2067 {
2068         while (n--) seq_printf(seq, " ");
2069 }
2070
2071 static void printbin_seq(struct seq_file *seq, unsigned int v, int bits)
2072 {
2073         while (bits--)
2074                 seq_printf(seq, "%s", (v & (1<<bits))?"1":"0");
2075 }
2076
2077 static void printnode_seq(struct seq_file *seq, int indent, struct node *n,
2078                    int pend, int cindex, int bits)
2079 {
2080         putspace_seq(seq, indent);
2081         if (IS_LEAF(n))
2082                 seq_printf(seq, "|");
2083         else
2084                 seq_printf(seq, "+");
2085         if (bits) {
2086                 seq_printf(seq, "%d/", cindex);
2087                 printbin_seq(seq, cindex, bits);
2088                 seq_printf(seq, ": ");
2089         }
2090         else
2091                 seq_printf(seq, "<root>: ");
2092         seq_printf(seq, "%s:%p ", IS_LEAF(n)?"Leaf":"Internal node", n);
2093
2094         if (IS_LEAF(n))
2095                 seq_printf(seq, "key=%d.%d.%d.%d\n",
2096                            n->key >> 24, (n->key >> 16) % 256, (n->key >> 8) % 256, n->key % 256);
2097         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                            prf >> 24, (prf >> 16) % 256, (prf >> 8) % 256, prf % 256, plen);
2102         }
2103         if (IS_LEAF(n)) {
2104                 struct leaf *l=(struct leaf *)n;
2105                 struct fib_alias *fa;
2106                 int i;
2107                 for (i=32; i>=0; i--)
2108                   if (find_leaf_info(&l->list, i)) {
2109
2110                                 struct list_head *fa_head = get_fa_head(l, i);
2111
2112                                 if (!fa_head)
2113                                         continue;
2114
2115                                 if (list_empty(fa_head))
2116                                         continue;
2117
2118                                 putspace_seq(seq, indent+2);
2119                                 seq_printf(seq, "{/%d...dumping}\n", i);
2120
2121
2122                                 list_for_each_entry(fa, fa_head, fa_list) {
2123                                         putspace_seq(seq, indent+2);
2124                                         if (fa->fa_info->fib_nh == NULL) {
2125                                                 seq_printf(seq, "Error _fib_nh=NULL\n");
2126                                                 continue;
2127                                         }
2128                                         if (fa->fa_info == NULL) {
2129                                                 seq_printf(seq, "Error fa_info=NULL\n");
2130                                                 continue;
2131                                         }
2132
2133                                         seq_printf(seq, "{type=%d scope=%d TOS=%d}\n",
2134                                               fa->fa_type,
2135                                               fa->fa_scope,
2136                                               fa->fa_tos);
2137                                 }
2138                         }
2139         }
2140         else if (IS_TNODE(n)) {
2141                 struct tnode *tn = (struct tnode *)n;
2142                 putspace_seq(seq, indent); seq_printf(seq, "|    ");
2143                 seq_printf(seq, "{key prefix=%08x/", tn->key&TKEY_GET_MASK(0, tn->pos));
2144                 printbin_seq(seq, tkey_extract_bits(tn->key, 0, tn->pos), tn->pos);
2145                 seq_printf(seq, "}\n");
2146                 putspace_seq(seq, indent); seq_printf(seq, "|    ");
2147                 seq_printf(seq, "{pos=%d", tn->pos);
2148                 seq_printf(seq, " (skip=%d bits)", tn->pos - pend);
2149                 seq_printf(seq, " bits=%d (%u children)}\n", tn->bits, (1 << tn->bits));
2150                 putspace_seq(seq, indent); seq_printf(seq, "|    ");
2151                 seq_printf(seq, "{empty=%d full=%d}\n", tn->empty_children, tn->full_children);
2152         }
2153 }
2154
2155 static void trie_dump_seq(struct seq_file *seq, struct trie *t)
2156 {
2157         struct node *n = t->trie;
2158         int cindex=0;
2159         int indent=1;
2160         int pend=0;
2161         int depth = 0;
2162
2163         read_lock(&fib_lock);
2164
2165         seq_printf(seq, "------ trie_dump of t=%p ------\n", t);
2166         if (n) {
2167                 printnode_seq(seq, indent, n, pend, cindex, 0);
2168                 if (IS_TNODE(n)) {
2169                         struct tnode *tn = (struct tnode *)n;
2170                         pend = tn->pos+tn->bits;
2171                         putspace_seq(seq, indent); seq_printf(seq, "\\--\n");
2172                         indent += 3;
2173                         depth++;
2174
2175                         while (tn && cindex < (1 << tn->bits)) {
2176                                 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                                                 n = tn->child[cindex];
2192                                                 tn = (struct tnode *)n;
2193                                                 pend = tn->pos+tn->bits;
2194                                                 putspace_seq(seq, indent); seq_printf(seq, "\\--\n");
2195                                                 indent+=3;
2196                                                 cindex=0;
2197                                         }
2198                                 }
2199                                 else
2200                                         cindex++;
2201
2202                                 /*
2203                                  * Test if we are done
2204                                  */
2205
2206                                 while (cindex >= (1 << tn->bits)) {
2207
2208                                         /*
2209                                          * Move upwards and test for root
2210                                          * pop off all traversed  nodes
2211                                          */
2212
2213                                         if (NODE_PARENT(tn) == NULL) {
2214                                                 tn = NULL;
2215                                                 n = NULL;
2216                                                 break;
2217                                         }
2218                                         else {
2219                                                 cindex = tkey_extract_bits(tn->key, NODE_PARENT(tn)->pos, NODE_PARENT(tn)->bits);
2220                                                 tn = NODE_PARENT(tn);
2221                                                 cindex++;
2222                                                 n = (struct node *)tn;
2223                                                 pend = tn->pos+tn->bits;
2224                                                 indent-=3;
2225                                                 depth--;
2226                                         }
2227                                 }
2228                         }
2229                 }
2230                 else n = NULL;
2231         }
2232         else seq_printf(seq, "------ trie is empty\n");
2233
2234         read_unlock(&fib_lock);
2235 }
2236
2237 static struct trie_stat *trie_stat_new(void)
2238 {
2239         struct trie_stat *s = kmalloc(sizeof(struct trie_stat), GFP_KERNEL);
2240         int i;
2241
2242         if (s) {
2243                 s->totdepth = 0;
2244                 s->maxdepth = 0;
2245                 s->tnodes = 0;
2246                 s->leaves = 0;
2247                 s->nullpointers = 0;
2248
2249                 for(i=0; i< MAX_CHILDS; i++)
2250                         s->nodesizes[i] = 0;
2251         }
2252         return s;
2253 }
2254
2255 static struct trie_stat *trie_collect_stats(struct trie *t)
2256 {
2257         struct node *n = t->trie;
2258         struct trie_stat *s = trie_stat_new();
2259         int cindex = 0;
2260         int indent = 1;
2261         int pend = 0;
2262         int depth = 0;
2263
2264         read_lock(&fib_lock);
2265
2266         if (s) {
2267                 if (n) {
2268                         if (IS_TNODE(n)) {
2269                                 struct tnode *tn = (struct tnode *)n;
2270                                 pend = tn->pos+tn->bits;
2271                                 indent += 3;
2272                                 s->nodesizes[tn->bits]++;
2273                                 depth++;
2274
2275                                 while (tn && cindex < (1 << tn->bits)) {
2276                                         if (tn->child[cindex]) {
2277                                                 /* Got a child */
2278
2279                                                 if (IS_LEAF(tn->child[cindex])) {
2280                                                         cindex++;
2281
2282                                                         /* stats */
2283                                                         if (depth > s->maxdepth)
2284                                                                 s->maxdepth = depth;
2285                                                         s->totdepth += depth;
2286                                                         s->leaves++;
2287                                                 }
2288
2289                                                 else {
2290                                                         /*
2291                                                          * New tnode. Decend one level
2292                                                          */
2293
2294                                                         s->tnodes++;
2295                                                         s->nodesizes[tn->bits]++;
2296                                                         depth++;
2297
2298                                                         n = tn->child[cindex];
2299                                                         tn = (struct tnode *)n;
2300                                                         pend = tn->pos+tn->bits;
2301
2302                                                         indent += 3;
2303                                                         cindex = 0;
2304                                                 }
2305                                         }
2306                                         else {
2307                                                 cindex++;
2308                                                 s->nullpointers++;
2309                                         }
2310
2311                                         /*
2312                                          * Test if we are done
2313                                          */
2314
2315                                         while (cindex >= (1 << tn->bits)) {
2316
2317                                                 /*
2318                                                  * Move upwards and test for root
2319                                                  * pop off all traversed  nodes
2320                                                  */
2321
2322
2323                                                 if (NODE_PARENT(tn) == NULL) {
2324                                                         tn = NULL;
2325                                                         n = NULL;
2326                                                         break;
2327                                                 }
2328                                                 else {
2329                                                         cindex = tkey_extract_bits(tn->key, NODE_PARENT(tn)->pos, NODE_PARENT(tn)->bits);
2330                                                         tn = NODE_PARENT(tn);
2331                                                         cindex++;
2332                                                         n = (struct node *)tn;
2333                                                         pend = tn->pos+tn->bits;
2334                                                         indent -= 3;
2335                                                         depth--;
2336                                                 }
2337                                         }
2338                                 }
2339                         }
2340                         else n = NULL;
2341                 }
2342         }
2343
2344         read_unlock(&fib_lock);
2345         return s;
2346 }
2347
2348 #ifdef CONFIG_PROC_FS
2349
2350 static struct fib_alias *fib_triestat_get_first(struct seq_file *seq)
2351 {
2352         return NULL;
2353 }
2354
2355 static struct fib_alias *fib_triestat_get_next(struct seq_file *seq)
2356 {
2357         return NULL;
2358 }
2359
2360 static void *fib_triestat_seq_start(struct seq_file *seq, loff_t *pos)
2361 {
2362         void *v = NULL;
2363
2364         if (ip_fib_main_table)
2365                 v = *pos ? fib_triestat_get_next(seq) : SEQ_START_TOKEN;
2366         return v;
2367 }
2368
2369 static void *fib_triestat_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2370 {
2371         ++*pos;
2372         return v == SEQ_START_TOKEN ? fib_triestat_get_first(seq) : fib_triestat_get_next(seq);
2373 }
2374
2375 static void fib_triestat_seq_stop(struct seq_file *seq, void *v)
2376 {
2377
2378 }
2379
2380 /*
2381  *      This outputs /proc/net/fib_triestats
2382  *
2383  *      It always works in backward compatibility mode.
2384  *      The format of the file is not supposed to be changed.
2385  */
2386
2387 static void collect_and_show(struct trie *t, struct seq_file *seq)
2388 {
2389         int bytes = 0; /* How many bytes are used, a ref is 4 bytes */
2390         int i, max, pointers;
2391         struct trie_stat *stat;
2392         int avdepth;
2393
2394         stat = trie_collect_stats(t);
2395
2396         bytes=0;
2397         seq_printf(seq, "trie=%p\n", t);
2398
2399         if (stat) {
2400                 if (stat->leaves)
2401                         avdepth=stat->totdepth*100 / stat->leaves;
2402                 else
2403                         avdepth=0;
2404                 seq_printf(seq, "Aver depth: %d.%02d\n", avdepth / 100, avdepth % 100 );
2405                 seq_printf(seq, "Max depth: %4d\n", stat->maxdepth);
2406
2407                 seq_printf(seq, "Leaves: %d\n", stat->leaves);
2408                 bytes += sizeof(struct leaf) * stat->leaves;
2409                 seq_printf(seq, "Internal nodes: %d\n", stat->tnodes);
2410                 bytes += sizeof(struct tnode) * stat->tnodes;
2411
2412                 max = MAX_CHILDS-1;
2413
2414                 while (max >= 0 && stat->nodesizes[max] == 0)
2415                         max--;
2416                 pointers = 0;
2417
2418                 for (i = 1; i <= max; i++)
2419                         if (stat->nodesizes[i] != 0) {
2420                                 seq_printf(seq, "  %d: %d",  i, stat->nodesizes[i]);
2421                                 pointers += (1<<i) * stat->nodesizes[i];
2422                         }
2423                 seq_printf(seq, "\n");
2424                 seq_printf(seq, "Pointers: %d\n", pointers);
2425                 bytes += sizeof(struct node *) * pointers;
2426                 seq_printf(seq, "Null ptrs: %d\n", stat->nullpointers);
2427                 seq_printf(seq, "Total size: %d  kB\n", bytes / 1024);
2428
2429                 kfree(stat);
2430         }
2431
2432 #ifdef CONFIG_IP_FIB_TRIE_STATS
2433         seq_printf(seq, "Counters:\n---------\n");
2434         seq_printf(seq,"gets = %d\n", t->stats.gets);
2435         seq_printf(seq,"backtracks = %d\n", t->stats.backtrack);
2436         seq_printf(seq,"semantic match passed = %d\n", t->stats.semantic_match_passed);
2437         seq_printf(seq,"semantic match miss = %d\n", t->stats.semantic_match_miss);
2438         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 #ifdef CLEAR_STATS
2441         memset(&(t->stats), 0, sizeof(t->stats));
2442 #endif
2443 #endif /*  CONFIG_IP_FIB_TRIE_STATS */
2444 }
2445
2446 static int fib_triestat_seq_show(struct seq_file *seq, void *v)
2447 {
2448         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                         collect_and_show(trie_local, seq);
2455
2456                 if (trie_main)
2457                         collect_and_show(trie_main, seq);
2458         }
2459         else {
2460                 snprintf(bf, sizeof(bf),
2461                          "*\t%08X\t%08X", 200, 400);
2462
2463                 seq_printf(seq, "%-127s\n", bf);
2464         }
2465         return 0;
2466 }
2467
2468 static struct seq_operations fib_triestat_seq_ops = {
2469         .start = fib_triestat_seq_start,
2470         .next  = fib_triestat_seq_next,
2471         .stop  = fib_triestat_seq_stop,
2472         .show  = fib_triestat_seq_show,
2473 };
2474
2475 static int fib_triestat_seq_open(struct inode *inode, struct file *file)
2476 {
2477         struct seq_file *seq;
2478         int rc = -ENOMEM;
2479
2480         rc = seq_open(file, &fib_triestat_seq_ops);
2481         if (rc)
2482                 goto out_kfree;
2483
2484         seq = file->private_data;
2485 out:
2486         return rc;
2487 out_kfree:
2488         goto out;
2489 }
2490
2491 static struct file_operations fib_triestat_seq_fops = {
2492         .owner  = THIS_MODULE,
2493         .open   = fib_triestat_seq_open,
2494         .read   = seq_read,
2495         .llseek = seq_lseek,
2496         .release = seq_release_private,
2497 };
2498
2499 int __init fib_stat_proc_init(void)
2500 {
2501         if (!proc_net_fops_create("fib_triestat", S_IRUGO, &fib_triestat_seq_fops))
2502                 return -ENOMEM;
2503         return 0;
2504 }
2505
2506 void __init fib_stat_proc_exit(void)
2507 {
2508         proc_net_remove("fib_triestat");
2509 }
2510
2511 static struct fib_alias *fib_trie_get_first(struct seq_file *seq)
2512 {
2513         return NULL;
2514 }
2515
2516 static struct fib_alias *fib_trie_get_next(struct seq_file *seq)
2517 {
2518         return NULL;
2519 }
2520
2521 static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2522 {
2523         void *v = NULL;
2524
2525         if (ip_fib_main_table)
2526                 v = *pos ? fib_trie_get_next(seq) : SEQ_START_TOKEN;
2527         return v;
2528 }
2529
2530 static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2531 {
2532         ++*pos;
2533         return v == SEQ_START_TOKEN ? fib_trie_get_first(seq) : fib_trie_get_next(seq);
2534 }
2535
2536 static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2537 {
2538
2539 }
2540
2541 /*
2542  *      This outputs /proc/net/fib_trie.
2543  *
2544  *      It always works in backward compatibility mode.
2545  *      The format of the file is not supposed to be changed.
2546  */
2547
2548 static int fib_trie_seq_show(struct seq_file *seq, void *v)
2549 {
2550         char bf[128];
2551
2552         if (v == SEQ_START_TOKEN) {
2553                 if (trie_local)
2554                         trie_dump_seq(seq, trie_local);
2555
2556                 if (trie_main)
2557                         trie_dump_seq(seq, trie_main);
2558         }
2559
2560         else {
2561                 snprintf(bf, sizeof(bf),
2562                          "*\t%08X\t%08X", 200, 400);
2563                 seq_printf(seq, "%-127s\n", bf);
2564         }
2565
2566         return 0;
2567 }
2568
2569 static struct seq_operations fib_trie_seq_ops = {
2570         .start = fib_trie_seq_start,
2571         .next  = fib_trie_seq_next,
2572         .stop  = fib_trie_seq_stop,
2573         .show  = fib_trie_seq_show,
2574 };
2575
2576 static int fib_trie_seq_open(struct inode *inode, struct file *file)
2577 {
2578         struct seq_file *seq;
2579         int rc = -ENOMEM;
2580
2581         rc = seq_open(file, &fib_trie_seq_ops);
2582         if (rc)
2583                 goto out_kfree;
2584
2585         seq = file->private_data;
2586 out:
2587         return rc;
2588 out_kfree:
2589         goto out;
2590 }
2591
2592 static struct file_operations fib_trie_seq_fops = {
2593         .owner  = THIS_MODULE,
2594         .open   = fib_trie_seq_open,
2595         .read   = seq_read,
2596         .llseek = seq_lseek,
2597         .release= seq_release_private,
2598 };
2599
2600 int __init fib_proc_init(void)
2601 {
2602         if (!proc_net_fops_create("fib_trie", S_IRUGO, &fib_trie_seq_fops))
2603                 return -ENOMEM;
2604         return 0;
2605 }
2606
2607 void __init fib_proc_exit(void)
2608 {
2609         proc_net_remove("fib_trie");
2610 }
2611
2612 #endif /* CONFIG_PROC_FS */