net/ipv4/fib_hash.c

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              IPv4 FIB: lookup engine and maintenance routines.
   7  *
   8  * Version:     $Id: fib_hash.c,v 1.13 2001/10/31 21:55:54 davem Exp $
   9  *
  10  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  11  *
  12  *              This program is free software; you can redistribute it and/or
  13  *              modify it under the terms of the GNU General Public License
  14  *              as published by the Free Software Foundation; either version
  15  *              2 of the License, or (at your option) any later version.
  16  */
  17
  18 #include <asm/uaccess.h>
  19 #include <asm/system.h>
  20 #include <linux/bitops.h>
  21 #include <linux/types.h>
  22 #include <linux/kernel.h>
  23 #include <linux/mm.h>
  24 #include <linux/string.h>
  25 #include <linux/socket.h>
  26 #include <linux/sockios.h>
  27 #include <linux/errno.h>
  28 #include <linux/in.h>
  29 #include <linux/inet.h>
  30 #include <linux/inetdevice.h>
  31 #include <linux/netdevice.h>
  32 #include <linux/if_arp.h>
  33 #include <linux/proc_fs.h>
  34 #include <linux/skbuff.h>
  35 #include <linux/netlink.h>
  36 #include <linux/init.h>
  37
  38 #include <net/ip.h>
  39 #include <net/protocol.h>
  40 #include <net/route.h>
  41 #include <net/tcp.h>
  42 #include <net/sock.h>
  43 #include <net/ip_fib.h>
  44
  45 #include "fib_lookup.h"
  46
  47 static struct kmem_cache *fn_hash_kmem __read_mostly;
  48 static struct kmem_cache *fn_alias_kmem __read_mostly;
  49
  50 struct fib_node {
  51         struct hlist_node       fn_hash;
  52         struct list_head        fn_alias;
  53         __be32                  fn_key;
  54 };
  55
  56 struct fn_zone {
  57         struct fn_zone          *fz_next;       /* Next not empty zone  */
  58         struct hlist_head       *fz_hash;       /* Hash table pointer   */
  59         int                     fz_nent;        /* Number of entries    */
  60
  61         int                     fz_divisor;     /* Hash divisor         */
  62         u32                     fz_hashmask;    /* (fz_divisor - 1)     */
  63 #define FZ_HASHMASK(fz)         ((fz)->fz_hashmask)
  64
  65         int                     fz_order;       /* Zone order           */
  66         __be32                  fz_mask;
  67 #define FZ_MASK(fz)             ((fz)->fz_mask)
  68 };
  69
  70 /* NOTE. On fast computers evaluation of fz_hashmask and fz_mask
  71  * can be cheaper than memory lookup, so that FZ_* macros are used.
  72  */
  73
  74 struct fn_hash {
  75         struct fn_zone  *fn_zones[33];
  76         struct fn_zone  *fn_zone_list;
  77 };
  78
  79 static inline u32 fn_hash(__be32 key, struct fn_zone *fz)
  80 {
  81         u32 h = ntohl(key)>>(32 - fz->fz_order);
  82         h ^= (h>>20);
  83         h ^= (h>>10);
  84         h ^= (h>>5);
  85         h &= FZ_HASHMASK(fz);
  86         return h;
  87 }
  88
  89 static inline __be32 fz_key(__be32 dst, struct fn_zone *fz)
  90 {
  91         return dst & FZ_MASK(fz);
  92 }
  93
  94 static DEFINE_RWLOCK(fib_hash_lock);
  95 static unsigned int fib_hash_genid;
  96
  97 #define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct hlist_head))
  98
  99 static struct hlist_head *fz_hash_alloc(int divisor)
 100 {
 101         unsigned long size = divisor * sizeof(struct hlist_head);
 102
 103         if (size <= PAGE_SIZE) {
 104                 return kmalloc(size, GFP_KERNEL);
 105         } else {
 106                 return (struct hlist_head *)
 107                         __get_free_pages(GFP_KERNEL, get_order(size));
 108         }
 109 }
 110
 111 /* The fib hash lock must be held when this is called. */
 112 static inline void fn_rebuild_zone(struct fn_zone *fz,
 113                                    struct hlist_head *old_ht,
 114                                    int old_divisor)
 115 {
 116         int i;
 117
 118         for (i = 0; i < old_divisor; i++) {
 119                 struct hlist_node *node, *n;
 120                 struct fib_node *f;
 121
 122                 hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) {
 123                         struct hlist_head *new_head;
 124
 125                         hlist_del(&f->fn_hash);
 126
 127                         new_head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
 128                         hlist_add_head(&f->fn_hash, new_head);
 129                 }
 130         }
 131 }
 132
 133 static void fz_hash_free(struct hlist_head *hash, int divisor)
 134 {
 135         unsigned long size = divisor * sizeof(struct hlist_head);
 136
 137         if (size <= PAGE_SIZE)
 138                 kfree(hash);
 139         else
 140                 free_pages((unsigned long)hash, get_order(size));
 141 }
 142
 143 static void fn_rehash_zone(struct fn_zone *fz)
 144 {
 145         struct hlist_head *ht, *old_ht;
 146         int old_divisor, new_divisor;
 147         u32 new_hashmask;
 148
 149         old_divisor = fz->fz_divisor;
 150
 151         switch (old_divisor) {
 152         case 16:
 153                 new_divisor = 256;
 154                 break;
 155         case 256:
 156                 new_divisor = 1024;
 157                 break;
 158         default:
 159                 if ((old_divisor << 1) > FZ_MAX_DIVISOR) {
 160                         printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor);
 161                         return;
 162                 }
 163                 new_divisor = (old_divisor << 1);
 164                 break;
 165         }
 166
 167         new_hashmask = (new_divisor - 1);
 168
 169 #if RT_CACHE_DEBUG >= 2
 170         printk("fn_rehash_zone: hash for zone %d grows from %d\n", fz->fz_order, old_divisor);
 171 #endif
 172
 173         ht = fz_hash_alloc(new_divisor);
 174
 175         if (ht) {
 176                 memset(ht, 0, new_divisor * sizeof(struct hlist_head));
 177
 178                 write_lock_bh(&fib_hash_lock);
 179                 old_ht = fz->fz_hash;
 180                 fz->fz_hash = ht;
 181                 fz->fz_hashmask = new_hashmask;
 182                 fz->fz_divisor = new_divisor;
 183                 fn_rebuild_zone(fz, old_ht, old_divisor);
 184                 fib_hash_genid++;
 185                 write_unlock_bh(&fib_hash_lock);
 186
 187                 fz_hash_free(old_ht, old_divisor);
 188         }
 189 }
 190
 191 static inline void fn_free_node(struct fib_node * f)
 192 {
 193         kmem_cache_free(fn_hash_kmem, f);
 194 }
 195
 196 static inline void fn_free_alias(struct fib_alias *fa)
 197 {
 198         fib_release_info(fa->fa_info);
 199         kmem_cache_free(fn_alias_kmem, fa);
 200 }
 201
 202 static struct fn_zone *
 203 fn_new_zone(struct fn_hash *table, int z)
 204 {
 205         int i;
 206         struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL);
 207         if (!fz)
 208                 return NULL;
 209
 210         if (z) {
 211                 fz->fz_divisor = 16;
 212         } else {
 213                 fz->fz_divisor = 1;
 214         }
 215         fz->fz_hashmask = (fz->fz_divisor - 1);
 216         fz->fz_hash = fz_hash_alloc(fz->fz_divisor);
 217         if (!fz->fz_hash) {
 218                 kfree(fz);
 219                 return NULL;
 220         }
 221         memset(fz->fz_hash, 0, fz->fz_divisor * sizeof(struct hlist_head *));
 222         fz->fz_order = z;
 223         fz->fz_mask = inet_make_mask(z);
 224
 225         /* Find the first not empty zone with more specific mask */
 226         for (i=z+1; i<=32; i++)
 227                 if (table->fn_zones[i])
 228                         break;
 229         write_lock_bh(&fib_hash_lock);
 230         if (i>32) {
 231                 /* No more specific masks, we are the first. */
 232                 fz->fz_next = table->fn_zone_list;
 233                 table->fn_zone_list = fz;
 234         } else {
 235                 fz->fz_next = table->fn_zones[i]->fz_next;
 236                 table->fn_zones[i]->fz_next = fz;
 237         }
 238         table->fn_zones[z] = fz;
 239         fib_hash_genid++;
 240         write_unlock_bh(&fib_hash_lock);
 241         return fz;
 242 }
 243
 244 static int
 245 fn_hash_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
 246 {
 247         int err;
 248         struct fn_zone *fz;
 249         struct fn_hash *t = (struct fn_hash*)tb->tb_data;
 250
 251         read_lock(&fib_hash_lock);
 252         for (fz = t->fn_zone_list; fz; fz = fz->fz_next) {
 253                 struct hlist_head *head;
 254                 struct hlist_node *node;
 255                 struct fib_node *f;
 256                 __be32 k = fz_key(flp->fl4_dst, fz);
 257
 258                 head = &fz->fz_hash[fn_hash(k, fz)];
 259                 hlist_for_each_entry(f, node, head, fn_hash) {
 260                         if (f->fn_key != k)
 261                                 continue;
 262
 263                         err = fib_semantic_match(&f->fn_alias,
 264                                                  flp, res,
 265                                                  f->fn_key, fz->fz_mask,
 266                                                  fz->fz_order);
 267                         if (err <= 0)
 268                                 goto out;
 269                 }
 270         }
 271         err = 1;
 272 out:
 273         read_unlock(&fib_hash_lock);
 274         return err;
 275 }
 276
 277 static int fn_hash_last_dflt=-1;
 278
 279 static void
 280 fn_hash_select_default(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
 281 {
 282         int order, last_idx;
 283         struct hlist_node *node;
 284         struct fib_node *f;
 285         struct fib_info *fi = NULL;
 286         struct fib_info *last_resort;
 287         struct fn_hash *t = (struct fn_hash*)tb->tb_data;
 288         struct fn_zone *fz = t->fn_zones[0];
 289
 290         if (fz == NULL)
 291                 return;
 292
 293         last_idx = -1;
 294         last_resort = NULL;
 295         order = -1;
 296
 297         read_lock(&fib_hash_lock);
 298         hlist_for_each_entry(f, node, &fz->fz_hash[0], fn_hash) {
 299                 struct fib_alias *fa;
 300
 301                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
 302                         struct fib_info *next_fi = fa->fa_info;
 303
 304                         if (fa->fa_scope != res->scope ||
 305                             fa->fa_type != RTN_UNICAST)
 306                                 continue;
 307
 308                         if (next_fi->fib_priority > res->fi->fib_priority)
 309                                 break;
 310                         if (!next_fi->fib_nh[0].nh_gw ||
 311                             next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
 312                                 continue;
 313                         fa->fa_state |= FA_S_ACCESSED;
 314
 315                         if (fi == NULL) {
 316                                 if (next_fi != res->fi)
 317                                         break;
 318                         } else if (!fib_detect_death(fi, order, &last_resort,
 319                                                      &last_idx, &fn_hash_last_dflt)) {
 320                                 if (res->fi)
 321                                         fib_info_put(res->fi);
 322                                 res->fi = fi;
 323                                 atomic_inc(&fi->fib_clntref);
 324                                 fn_hash_last_dflt = order;
 325                                 goto out;
 326                         }
 327                         fi = next_fi;
 328                         order++;
 329                 }
 330         }
 331
 332         if (order <= 0 || fi == NULL) {
 333                 fn_hash_last_dflt = -1;
 334                 goto out;
 335         }
 336
 337         if (!fib_detect_death(fi, order, &last_resort, &last_idx, &fn_hash_last_dflt)) {
 338                 if (res->fi)
 339                         fib_info_put(res->fi);
 340                 res->fi = fi;
 341                 atomic_inc(&fi->fib_clntref);
 342                 fn_hash_last_dflt = order;
 343                 goto out;
 344         }
 345
 346         if (last_idx >= 0) {
 347                 if (res->fi)
 348                         fib_info_put(res->fi);
 349                 res->fi = last_resort;
 350                 if (last_resort)
 351                         atomic_inc(&last_resort->fib_clntref);
 352         }
 353         fn_hash_last_dflt = last_idx;
 354 out:
 355         read_unlock(&fib_hash_lock);
 356 }
 357
 358 /* Insert node F to FZ. */
 359 static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
 360 {
 361         struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
 362
 363         hlist_add_head(&f->fn_hash, head);
 364 }
 365
 366 /* Return the node in FZ matching KEY. */
 367 static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
 368 {
 369         struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)];
 370         struct hlist_node *node;
 371         struct fib_node *f;
 372
 373         hlist_for_each_entry(f, node, head, fn_hash) {
 374                 if (f->fn_key == key)
 375                         return f;
 376         }
 377
 378         return NULL;
 379 }
 380
 381 static int fn_hash_insert(struct fib_table *tb, struct fib_config *cfg)
 382 {
 383         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
 384         struct fib_node *new_f, *f;
 385         struct fib_alias *fa, *new_fa;
 386         struct fn_zone *fz;
 387         struct fib_info *fi;
 388         u8 tos = cfg->fc_tos;
 389         __be32 key;
 390         int err;
 391
 392         if (cfg->fc_dst_len > 32)
 393                 return -EINVAL;
 394
 395         fz = table->fn_zones[cfg->fc_dst_len];
 396         if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
 397                 return -ENOBUFS;
 398
 399         key = 0;
 400         if (cfg->fc_dst) {
 401                 if (cfg->fc_dst & ~FZ_MASK(fz))
 402                         return -EINVAL;
 403                 key = fz_key(cfg->fc_dst, fz);
 404         }
 405
 406         fi = fib_create_info(cfg);
 407         if (IS_ERR(fi))
 408                 return PTR_ERR(fi);
 409
 410         if (fz->fz_nent > (fz->fz_divisor<<1) &&
 411             fz->fz_divisor < FZ_MAX_DIVISOR &&
 412             (cfg->fc_dst_len == 32 ||
 413              (1 << cfg->fc_dst_len) > fz->fz_divisor))
 414                 fn_rehash_zone(fz);
 415
 416         f = fib_find_node(fz, key);
 417
 418         if (!f)
 419                 fa = NULL;
 420         else
 421                 fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
 422
 423         /* Now fa, if non-NULL, points to the first fib alias
 424          * with the same keys [prefix,tos,priority], if such key already
 425          * exists or to the node before which we will insert new one.
 426          *
 427          * If fa is NULL, we will need to allocate a new one and
 428          * insert to the head of f.
 429          *
 430          * If f is NULL, no fib node matched the destination key
 431          * and we need to allocate a new one of those as well.
 432          */
 433
 434         if (fa && fa->fa_tos == tos &&
 435             fa->fa_info->fib_priority == fi->fib_priority) {
 436                 struct fib_alias *fa_orig;
 437
 438                 err = -EEXIST;
 439                 if (cfg->fc_nlflags & NLM_F_EXCL)
 440                         goto out;
 441
 442                 if (cfg->fc_nlflags & NLM_F_REPLACE) {
 443                         struct fib_info *fi_drop;
 444                         u8 state;
 445
 446                         write_lock_bh(&fib_hash_lock);
 447                         fi_drop = fa->fa_info;
 448                         fa->fa_info = fi;
 449                         fa->fa_type = cfg->fc_type;
 450                         fa->fa_scope = cfg->fc_scope;
 451                         state = fa->fa_state;
 452                         fa->fa_state &= ~FA_S_ACCESSED;
 453                         fib_hash_genid++;
 454                         write_unlock_bh(&fib_hash_lock);
 455
 456                         fib_release_info(fi_drop);
 457                         if (state & FA_S_ACCESSED)
 458                                 rt_cache_flush(-1);
 459                         return 0;
 460                 }
 461
 462                 /* Error if we find a perfect match which
 463                  * uses the same scope, type, and nexthop
 464                  * information.
 465                  */
 466                 fa_orig = fa;
 467                 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
 468                 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
 469                         if (fa->fa_tos != tos)
 470                                 break;
 471                         if (fa->fa_info->fib_priority != fi->fib_priority)
 472                                 break;
 473                         if (fa->fa_type == cfg->fc_type &&
 474                             fa->fa_scope == cfg->fc_scope &&
 475                             fa->fa_info == fi)
 476                                 goto out;
 477                 }
 478                 if (!(cfg->fc_nlflags & NLM_F_APPEND))
 479                         fa = fa_orig;
 480         }
 481
 482         err = -ENOENT;
 483         if (!(cfg->fc_nlflags & NLM_F_CREATE))
 484                 goto out;
 485
 486         err = -ENOBUFS;
 487         new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
 488         if (new_fa == NULL)
 489                 goto out;
 490
 491         new_f = NULL;
 492         if (!f) {
 493                 new_f = kmem_cache_alloc(fn_hash_kmem, GFP_KERNEL);
 494                 if (new_f == NULL)
 495                         goto out_free_new_fa;
 496
 497                 INIT_HLIST_NODE(&new_f->fn_hash);
 498                 INIT_LIST_HEAD(&new_f->fn_alias);
 499                 new_f->fn_key = key;
 500                 f = new_f;
 501         }
 502
 503         new_fa->fa_info = fi;
 504         new_fa->fa_tos = tos;
 505         new_fa->fa_type = cfg->fc_type;
 506         new_fa->fa_scope = cfg->fc_scope;
 507         new_fa->fa_state = 0;
 508
 509         /*
 510          * Insert new entry to the list.
 511          */
 512
 513         write_lock_bh(&fib_hash_lock);
 514         if (new_f)
 515                 fib_insert_node(fz, new_f);
 516         list_add_tail(&new_fa->fa_list,
 517                  (fa ? &fa->fa_list : &f->fn_alias));
 518         fib_hash_genid++;
 519         write_unlock_bh(&fib_hash_lock);
 520
 521         if (new_f)
 522                 fz->fz_nent++;
 523         rt_cache_flush(-1);
 524
 525         rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
 526                   &cfg->fc_nlinfo);
 527         return 0;
 528
 529 out_free_new_fa:
 530         kmem_cache_free(fn_alias_kmem, new_fa);
 531 out:
 532         fib_release_info(fi);
 533         return err;
 534 }
 535
 536
 537 static int fn_hash_delete(struct fib_table *tb, struct fib_config *cfg)
 538 {
 539         struct fn_hash *table = (struct fn_hash*)tb->tb_data;
 540         struct fib_node *f;
 541         struct fib_alias *fa, *fa_to_delete;
 542         struct fn_zone *fz;
 543         __be32 key;
 544
 545         if (cfg->fc_dst_len > 32)
 546                 return -EINVAL;
 547
 548         if ((fz  = table->fn_zones[cfg->fc_dst_len]) == NULL)
 549                 return -ESRCH;
 550
 551         key = 0;
 552         if (cfg->fc_dst) {
 553                 if (cfg->fc_dst & ~FZ_MASK(fz))
 554                         return -EINVAL;
 555                 key = fz_key(cfg->fc_dst, fz);
 556         }
 557
 558         f = fib_find_node(fz, key);
 559
 560         if (!f)
 561                 fa = NULL;
 562         else
 563                 fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
 564         if (!fa)
 565                 return -ESRCH;
 566
 567         fa_to_delete = NULL;
 568         fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
 569         list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
 570                 struct fib_info *fi = fa->fa_info;
 571
 572                 if (fa->fa_tos != cfg->fc_tos)
 573                         break;
 574
 575                 if ((!cfg->fc_type ||
 576                      fa->fa_type == cfg->fc_type) &&
 577                     (cfg->fc_scope == RT_SCOPE_NOWHERE ||
 578                      fa->fa_scope == cfg->fc_scope) &&
 579                     (!cfg->fc_protocol ||
 580                      fi->fib_protocol == cfg->fc_protocol) &&
 581                     fib_nh_match(cfg, fi) == 0) {
 582                         fa_to_delete = fa;
 583                         break;
 584                 }
 585         }
 586
 587         if (fa_to_delete) {
 588                 int kill_fn;
 589
 590                 fa = fa_to_delete;
 591                 rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
 592                           tb->tb_id, &cfg->fc_nlinfo);
 593
 594                 kill_fn = 0;
 595                 write_lock_bh(&fib_hash_lock);
 596                 list_del(&fa->fa_list);
 597                 if (list_empty(&f->fn_alias)) {
 598                         hlist_del(&f->fn_hash);
 599                         kill_fn = 1;
 600                 }
 601                 fib_hash_genid++;
 602                 write_unlock_bh(&fib_hash_lock);
 603
 604                 if (fa->fa_state & FA_S_ACCESSED)
 605                         rt_cache_flush(-1);
 606                 fn_free_alias(fa);
 607                 if (kill_fn) {
 608                         fn_free_node(f);
 609                         fz->fz_nent--;
 610                 }
 611
 612                 return 0;
 613         }
 614         return -ESRCH;
 615 }
 616
 617 static int fn_flush_list(struct fn_zone *fz, int idx)
 618 {
 619         struct hlist_head *head = &fz->fz_hash[idx];
 620         struct hlist_node *node, *n;
 621         struct fib_node *f;
 622         int found = 0;
 623
 624         hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
 625                 struct fib_alias *fa, *fa_node;
 626                 int kill_f;
 627
 628                 kill_f = 0;
 629                 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
 630                         struct fib_info *fi = fa->fa_info;
 631
 632                         if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
 633                                 write_lock_bh(&fib_hash_lock);
 634                                 list_del(&fa->fa_list);
 635                                 if (list_empty(&f->fn_alias)) {
 636                                         hlist_del(&f->fn_hash);
 637                                         kill_f = 1;
 638                                 }
 639                                 fib_hash_genid++;
 640                                 write_unlock_bh(&fib_hash_lock);
 641
 642                                 fn_free_alias(fa);
 643                                 found++;
 644                         }
 645                 }
 646                 if (kill_f) {
 647                         fn_free_node(f);
 648                         fz->fz_nent--;
 649                 }
 650         }
 651         return found;
 652 }
 653
 654 static int fn_hash_flush(struct fib_table *tb)
 655 {
 656         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
 657         struct fn_zone *fz;
 658         int found = 0;
 659
 660         for (fz = table->fn_zone_list; fz; fz = fz->fz_next) {
 661                 int i;
 662
 663                 for (i = fz->fz_divisor - 1; i >= 0; i--)
 664                         found += fn_flush_list(fz, i);
 665         }
 666         return found;
 667 }
 668
 669
 670 static inline int
 671 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
 672                      struct fib_table *tb,
 673                      struct fn_zone *fz,
 674                      struct hlist_head *head)
 675 {
 676         struct hlist_node *node;
 677         struct fib_node *f;
 678         int i, s_i;
 679
 680         s_i = cb->args[4];
 681         i = 0;
 682         hlist_for_each_entry(f, node, head, fn_hash) {
 683                 struct fib_alias *fa;
 684
 685                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
 686                         if (i < s_i)
 687                                 goto next;
 688
 689                         if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 690                                           cb->nlh->nlmsg_seq,
 691                                           RTM_NEWROUTE,
 692                                           tb->tb_id,
 693                                           fa->fa_type,
 694                                           fa->fa_scope,
 695                                           f->fn_key,
 696                                           fz->fz_order,
 697                                           fa->fa_tos,
 698                                           fa->fa_info,
 699                                           NLM_F_MULTI) < 0) {
 700                                 cb->args[4] = i;
 701                                 return -1;
 702                         }
 703                 next:
 704                         i++;
 705                 }
 706         }
 707         cb->args[4] = i;
 708         return skb->len;
 709 }
 710
 711 static inline int
 712 fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
 713                    struct fib_table *tb,
 714                    struct fn_zone *fz)
 715 {
 716         int h, s_h;
 717
 718         s_h = cb->args[3];
 719         for (h=0; h < fz->fz_divisor; h++) {
 720                 if (h < s_h) continue;
 721                 if (h > s_h)
 722                         memset(&cb->args[4], 0,
 723                                sizeof(cb->args) - 4*sizeof(cb->args[0]));
 724                 if (fz->fz_hash == NULL ||
 725                     hlist_empty(&fz->fz_hash[h]))
 726                         continue;
 727                 if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h])<0) {
 728                         cb->args[3] = h;
 729                         return -1;
 730                 }
 731         }
 732         cb->args[3] = h;
 733         return skb->len;
 734 }
 735
 736 static int fn_hash_dump(struct fib_table *tb, struct sk_buff *skb, struct netlink_callback *cb)
 737 {
 738         int m, s_m;
 739         struct fn_zone *fz;
 740         struct fn_hash *table = (struct fn_hash*)tb->tb_data;
 741
 742         s_m = cb->args[2];
 743         read_lock(&fib_hash_lock);
 744         for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) {
 745                 if (m < s_m) continue;
 746                 if (m > s_m)
 747                         memset(&cb->args[3], 0,
 748                                sizeof(cb->args) - 3*sizeof(cb->args[0]));
 749                 if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
 750                         cb->args[2] = m;
 751                         read_unlock(&fib_hash_lock);
 752                         return -1;
 753                 }
 754         }
 755         read_unlock(&fib_hash_lock);
 756         cb->args[2] = m;
 757         return skb->len;
 758 }
 759
 760 #ifdef CONFIG_IP_MULTIPLE_TABLES
 761 struct fib_table * fib_hash_init(u32 id)
 762 #else
 763 struct fib_table * __init fib_hash_init(u32 id)
 764 #endif
 765 {
 766         struct fib_table *tb;
 767
 768         if (fn_hash_kmem == NULL)
 769                 fn_hash_kmem = kmem_cache_create("ip_fib_hash",
 770                                                  sizeof(struct fib_node),
 771                                                  0, SLAB_HWCACHE_ALIGN,
 772                                                  NULL, NULL);
 773
 774         if (fn_alias_kmem == NULL)
 775                 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
 776                                                   sizeof(struct fib_alias),
 777                                                   0, SLAB_HWCACHE_ALIGN,
 778                                                   NULL, NULL);
 779
 780         tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash),
 781                      GFP_KERNEL);
 782         if (tb == NULL)
 783                 return NULL;
 784
 785         tb->tb_id = id;
 786         tb->tb_lookup = fn_hash_lookup;
 787         tb->tb_insert = fn_hash_insert;
 788         tb->tb_delete = fn_hash_delete;
 789         tb->tb_flush = fn_hash_flush;
 790         tb->tb_select_default = fn_hash_select_default;
 791         tb->tb_dump = fn_hash_dump;
 792         memset(tb->tb_data, 0, sizeof(struct fn_hash));
 793         return tb;
 794 }
 795
 796 /* ------------------------------------------------------------------------ */
 797 #ifdef CONFIG_PROC_FS
 798
 799 struct fib_iter_state {
 800         struct fn_zone  *zone;
 801         int             bucket;
 802         struct hlist_head *hash_head;
 803         struct fib_node *fn;
 804         struct fib_alias *fa;
 805         loff_t pos;
 806         unsigned int genid;
 807         int valid;
 808 };
 809
 810 static struct fib_alias *fib_get_first(struct seq_file *seq)
 811 {
 812         struct fib_iter_state *iter = seq->private;
 813         struct fn_hash *table = (struct fn_hash *) ip_fib_main_table->tb_data;
 814
 815         iter->bucket    = 0;
 816         iter->hash_head = NULL;
 817         iter->fn        = NULL;
 818         iter->fa        = NULL;
 819         iter->pos       = 0;
 820         iter->genid     = fib_hash_genid;
 821         iter->valid     = 1;
 822
 823         for (iter->zone = table->fn_zone_list; iter->zone;
 824              iter->zone = iter->zone->fz_next) {
 825                 int maxslot;
 826
 827                 if (!iter->zone->fz_nent)
 828                         continue;
 829
 830                 iter->hash_head = iter->zone->fz_hash;
 831                 maxslot = iter->zone->fz_divisor;
 832
 833                 for (iter->bucket = 0; iter->bucket < maxslot;
 834                      ++iter->bucket, ++iter->hash_head) {
 835                         struct hlist_node *node;
 836                         struct fib_node *fn;
 837
 838                         hlist_for_each_entry(fn,node,iter->hash_head,fn_hash) {
 839                                 struct fib_alias *fa;
 840
 841                                 list_for_each_entry(fa,&fn->fn_alias,fa_list) {
 842                                         iter->fn = fn;
 843                                         iter->fa = fa;
 844                                         goto out;
 845                                 }
 846                         }
 847                 }
 848         }
 849 out:
 850         return iter->fa;
 851 }
 852
 853 static struct fib_alias *fib_get_next(struct seq_file *seq)
 854 {
 855         struct fib_iter_state *iter = seq->private;
 856         struct fib_node *fn;
 857         struct fib_alias *fa;
 858
 859         /* Advance FA, if any. */
 860         fn = iter->fn;
 861         fa = iter->fa;
 862         if (fa) {
 863                 BUG_ON(!fn);
 864                 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
 865                         iter->fa = fa;
 866                         goto out;
 867                 }
 868         }
 869
 870         fa = iter->fa = NULL;
 871
 872         /* Advance FN. */
 873         if (fn) {
 874                 struct hlist_node *node = &fn->fn_hash;
 875                 hlist_for_each_entry_continue(fn, node, fn_hash) {
 876                         iter->fn = fn;
 877
 878                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
 879                                 iter->fa = fa;
 880                                 goto out;
 881                         }
 882                 }
 883         }
 884
 885         fn = iter->fn = NULL;
 886
 887         /* Advance hash chain. */
 888         if (!iter->zone)
 889                 goto out;
 890
 891         for (;;) {
 892                 struct hlist_node *node;
 893                 int maxslot;
 894
 895                 maxslot = iter->zone->fz_divisor;
 896
 897                 while (++iter->bucket < maxslot) {
 898                         iter->hash_head++;
 899
 900                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
 901                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
 902                                         iter->fn = fn;
 903                                         iter->fa = fa;
 904                                         goto out;
 905                                 }
 906                         }
 907                 }
 908
 909                 iter->zone = iter->zone->fz_next;
 910
 911                 if (!iter->zone)
 912                         goto out;
 913
 914                 iter->bucket = 0;
 915                 iter->hash_head = iter->zone->fz_hash;
 916
 917                 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
 918                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
 919                                 iter->fn = fn;
 920                                 iter->fa = fa;
 921                                 goto out;
 922                         }
 923                 }
 924         }
 925 out:
 926         iter->pos++;
 927         return fa;
 928 }
 929
 930 static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
 931 {
 932         struct fib_iter_state *iter = seq->private;
 933         struct fib_alias *fa;
 934
 935         if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
 936                 fa   = iter->fa;
 937                 pos -= iter->pos;
 938         } else
 939                 fa = fib_get_first(seq);
 940
 941         if (fa)
 942                 while (pos && (fa = fib_get_next(seq)))
 943                         --pos;
 944         return pos ? NULL : fa;
 945 }
 946
 947 static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
 948 {
 949         void *v = NULL;
 950
 951         read_lock(&fib_hash_lock);
 952         if (ip_fib_main_table)
 953                 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 954         return v;
 955 }
 956
 957 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 958 {
 959         ++*pos;
 960         return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
 961 }
 962
 963 static void fib_seq_stop(struct seq_file *seq, void *v)
 964 {
 965         read_unlock(&fib_hash_lock);
 966 }
 967
 968 static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
 969 {
 970         static const unsigned type2flags[RTN_MAX + 1] = {
 971                 [7] = RTF_REJECT, [8] = RTF_REJECT,
 972         };
 973         unsigned flags = type2flags[type];
 974
 975         if (fi && fi->fib_nh->nh_gw)
 976                 flags |= RTF_GATEWAY;
 977         if (mask == htonl(0xFFFFFFFF))
 978                 flags |= RTF_HOST;
 979         flags |= RTF_UP;
 980         return flags;
 981 }
 982
 983 /*
 984  *      This outputs /proc/net/route.
 985  *
 986  *      It always works in backward compatibility mode.
 987  *      The format of the file is not supposed to be changed.
 988  */
 989 static int fib_seq_show(struct seq_file *seq, void *v)
 990 {
 991         struct fib_iter_state *iter;
 992         char bf[128];
 993         __be32 prefix, mask;
 994         unsigned flags;
 995         struct fib_node *f;
 996         struct fib_alias *fa;
 997         struct fib_info *fi;
 998
 999         if (v == SEQ_START_TOKEN) {
1000                 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
1001                            "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
1002                            "\tWindow\tIRTT");
1003                 goto out;
1004         }
1005
1006         iter    = seq->private;
1007         f       = iter->fn;
1008         fa      = iter->fa;
1009         fi      = fa->fa_info;
1010         prefix  = f->fn_key;
1011         mask    = FZ_MASK(iter->zone);
1012         flags   = fib_flag_trans(fa->fa_type, mask, fi);
1013         if (fi)
1014                 snprintf(bf, sizeof(bf),
1015                          "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1016                          fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1017                          fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1018                          mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1019                          fi->fib_window,
1020                          fi->fib_rtt >> 3);
1021         else
1022                 snprintf(bf, sizeof(bf),
1023                          "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1024                          prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0);
1025         seq_printf(seq, "%-127s\n", bf);
1026 out:
1027         return 0;
1028 }
1029
1030 static struct seq_operations fib_seq_ops = {
1031         .start  = fib_seq_start,
1032         .next   = fib_seq_next,
1033         .stop   = fib_seq_stop,
1034         .show   = fib_seq_show,
1035 };
1036
1037 static int fib_seq_open(struct inode *inode, struct file *file)
1038 {
1039         struct seq_file *seq;
1040         int rc = -ENOMEM;
1041         struct fib_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
1042
1043         if (!s)
1044                 goto out;
1045
1046         rc = seq_open(file, &fib_seq_ops);
1047         if (rc)
1048                 goto out_kfree;
1049
1050         seq          = file->private_data;
1051         seq->private = s;
1052 out:
1053         return rc;
1054 out_kfree:
1055         kfree(s);
1056         goto out;
1057 }
1058
1059 static const struct file_operations fib_seq_fops = {
1060         .owner          = THIS_MODULE,
1061         .open           = fib_seq_open,
1062         .read           = seq_read,
1063         .llseek         = seq_lseek,
1064         .release        = seq_release_private,
1065 };
1066
1067 int __init fib_proc_init(void)
1068 {
1069         if (!proc_net_fops_create("route", S_IRUGO, &fib_seq_fops))
1070                 return -ENOMEM;
1071         return 0;
1072 }
1073
1074 void __init fib_proc_exit(void)
1075 {
1076         proc_net_remove("route");
1077 }
1078 #endif /* CONFIG_PROC_FS */