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 <linux/config.h>
  19 #include <asm/uaccess.h>
  20 #include <asm/system.h>
  21 #include <linux/bitops.h>
  22 #include <linux/types.h>
  23 #include <linux/kernel.h>
  24 #include <linux/sched.h>
  25 #include <linux/mm.h>
  26 #include <linux/string.h>
  27 #include <linux/socket.h>
  28 #include <linux/sockios.h>
  29 #include <linux/errno.h>
  30 #include <linux/in.h>
  31 #include <linux/inet.h>
  32 #include <linux/inetdevice.h>
  33 #include <linux/netdevice.h>
  34 #include <linux/if_arp.h>
  35 #include <linux/proc_fs.h>
  36 #include <linux/skbuff.h>
  37 #include <linux/netlink.h>
  38 #include <linux/init.h>
  39
  40 #include <net/ip.h>
  41 #include <net/protocol.h>
  42 #include <net/route.h>
  43 #include <net/tcp.h>
  44 #include <net/sock.h>
  45 #include <net/ip_fib.h>
  46
  47 #include "fib_lookup.h"
  48
  49 static kmem_cache_t *fn_hash_kmem __read_mostly;
  50 static kmem_cache_t *fn_alias_kmem __read_mostly;
  51
  52 struct fib_node {
  53         struct hlist_node       fn_hash;
  54         struct list_head        fn_alias;
  55         u32                     fn_key;
  56 };
  57
  58 struct fn_zone {
  59         struct fn_zone          *fz_next;       /* Next not empty zone  */
  60         struct hlist_head       *fz_hash;       /* Hash table pointer   */
  61         int                     fz_nent;        /* Number of entries    */
  62
  63         int                     fz_divisor;     /* Hash divisor         */
  64         u32                     fz_hashmask;    /* (fz_divisor - 1)     */
  65 #define FZ_HASHMASK(fz)         ((fz)->fz_hashmask)
  66
  67         int                     fz_order;       /* Zone order           */
  68         u32                     fz_mask;
  69 #define FZ_MASK(fz)             ((fz)->fz_mask)
  70 };
  71
  72 /* NOTE. On fast computers evaluation of fz_hashmask and fz_mask
  73  * can be cheaper than memory lookup, so that FZ_* macros are used.
  74  */
  75
  76 struct fn_hash {
  77         struct fn_zone  *fn_zones[33];
  78         struct fn_zone  *fn_zone_list;
  79 };
  80
  81 static inline u32 fn_hash(u32 key, struct fn_zone *fz)
  82 {
  83         u32 h = ntohl(key)>>(32 - fz->fz_order);
  84         h ^= (h>>20);
  85         h ^= (h>>10);
  86         h ^= (h>>5);
  87         h &= FZ_HASHMASK(fz);
  88         return h;
  89 }
  90
  91 static inline u32 fz_key(u32 dst, struct fn_zone *fz)
  92 {
  93         return dst & FZ_MASK(fz);
  94 }
  95
  96 static DEFINE_RWLOCK(fib_hash_lock);
  97 static unsigned int fib_hash_genid;
  98
  99 #define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct hlist_head))
 100
 101 static struct hlist_head *fz_hash_alloc(int divisor)
 102 {
 103         unsigned long size = divisor * sizeof(struct hlist_head);
 104
 105         if (size <= PAGE_SIZE) {
 106                 return kmalloc(size, GFP_KERNEL);
 107         } else {
 108                 return (struct hlist_head *)
 109                         __get_free_pages(GFP_KERNEL, get_order(size));
 110         }
 111 }
 112
 113 /* The fib hash lock must be held when this is called. */
 114 static inline void fn_rebuild_zone(struct fn_zone *fz,
 115                                    struct hlist_head *old_ht,
 116                                    int old_divisor)
 117 {
 118         int i;
 119
 120         for (i = 0; i < old_divisor; i++) {
 121                 struct hlist_node *node, *n;
 122                 struct fib_node *f;
 123
 124                 hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) {
 125                         struct hlist_head *new_head;
 126
 127                         hlist_del(&f->fn_hash);
 128
 129                         new_head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
 130                         hlist_add_head(&f->fn_hash, new_head);
 131                 }
 132         }
 133 }
 134
 135 static void fz_hash_free(struct hlist_head *hash, int divisor)
 136 {
 137         unsigned long size = divisor * sizeof(struct hlist_head);
 138
 139         if (size <= PAGE_SIZE)
 140                 kfree(hash);
 141         else
 142                 free_pages((unsigned long)hash, get_order(size));
 143 }
 144
 145 static void fn_rehash_zone(struct fn_zone *fz)
 146 {
 147         struct hlist_head *ht, *old_ht;
 148         int old_divisor, new_divisor;
 149         u32 new_hashmask;
 150
 151         old_divisor = fz->fz_divisor;
 152
 153         switch (old_divisor) {
 154         case 16:
 155                 new_divisor = 256;
 156                 break;
 157         case 256:
 158                 new_divisor = 1024;
 159                 break;
 160         default:
 161                 if ((old_divisor << 1) > FZ_MAX_DIVISOR) {
 162                         printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor);
 163                         return;
 164                 }
 165                 new_divisor = (old_divisor << 1);
 166                 break;
 167         }
 168
 169         new_hashmask = (new_divisor - 1);
 170
 171 #if RT_CACHE_DEBUG >= 2
 172         printk("fn_rehash_zone: hash for zone %d grows from %d\n", fz->fz_order, old_divisor);
 173 #endif
 174
 175         ht = fz_hash_alloc(new_divisor);
 176
 177         if (ht) {
 178                 memset(ht, 0, new_divisor * sizeof(struct hlist_head));
 179
 180                 write_lock_bh(&fib_hash_lock);
 181                 old_ht = fz->fz_hash;
 182                 fz->fz_hash = ht;
 183                 fz->fz_hashmask = new_hashmask;
 184                 fz->fz_divisor = new_divisor;
 185                 fn_rebuild_zone(fz, old_ht, old_divisor);
 186                 fib_hash_genid++;
 187                 write_unlock_bh(&fib_hash_lock);
 188
 189                 fz_hash_free(old_ht, old_divisor);
 190         }
 191 }
 192
 193 static inline void fn_free_node(struct fib_node * f)
 194 {
 195         kmem_cache_free(fn_hash_kmem, f);
 196 }
 197
 198 static inline void fn_free_alias(struct fib_alias *fa)
 199 {
 200         fib_release_info(fa->fa_info);
 201         kmem_cache_free(fn_alias_kmem, fa);
 202 }
 203
 204 static struct fn_zone *
 205 fn_new_zone(struct fn_hash *table, int z)
 206 {
 207         int i;
 208         struct fn_zone *fz = kmalloc(sizeof(struct fn_zone), GFP_KERNEL);
 209         if (!fz)
 210                 return NULL;
 211
 212         memset(fz, 0, sizeof(struct fn_zone));
 213         if (z) {
 214                 fz->fz_divisor = 16;
 215         } else {
 216                 fz->fz_divisor = 1;
 217         }
 218         fz->fz_hashmask = (fz->fz_divisor - 1);
 219         fz->fz_hash = fz_hash_alloc(fz->fz_divisor);
 220         if (!fz->fz_hash) {
 221                 kfree(fz);
 222                 return NULL;
 223         }
 224         memset(fz->fz_hash, 0, fz->fz_divisor * sizeof(struct hlist_head *));
 225         fz->fz_order = z;
 226         fz->fz_mask = inet_make_mask(z);
 227
 228         /* Find the first not empty zone with more specific mask */
 229         for (i=z+1; i<=32; i++)
 230                 if (table->fn_zones[i])
 231                         break;
 232         write_lock_bh(&fib_hash_lock);
 233         if (i>32) {
 234                 /* No more specific masks, we are the first. */
 235                 fz->fz_next = table->fn_zone_list;
 236                 table->fn_zone_list = fz;
 237         } else {
 238                 fz->fz_next = table->fn_zones[i]->fz_next;
 239                 table->fn_zones[i]->fz_next = fz;
 240         }
 241         table->fn_zones[z] = fz;
 242         fib_hash_genid++;
 243         write_unlock_bh(&fib_hash_lock);
 244         return fz;
 245 }
 246
 247 static int
 248 fn_hash_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
 249 {
 250         int err;
 251         struct fn_zone *fz;
 252         struct fn_hash *t = (struct fn_hash*)tb->tb_data;
 253
 254         read_lock(&fib_hash_lock);
 255         for (fz = t->fn_zone_list; fz; fz = fz->fz_next) {
 256                 struct hlist_head *head;
 257                 struct hlist_node *node;
 258                 struct fib_node *f;
 259                 u32 k = fz_key(flp->fl4_dst, fz);
 260
 261                 head = &fz->fz_hash[fn_hash(k, fz)];
 262                 hlist_for_each_entry(f, node, head, fn_hash) {
 263                         if (f->fn_key != k)
 264                                 continue;
 265
 266                         err = fib_semantic_match(&f->fn_alias,
 267                                                  flp, res,
 268                                                  f->fn_key, fz->fz_mask,
 269                                                  fz->fz_order);
 270                         if (err <= 0)
 271                                 goto out;
 272                 }
 273         }
 274         err = 1;
 275 out:
 276         read_unlock(&fib_hash_lock);
 277         return err;
 278 }
 279
 280 static int fn_hash_last_dflt=-1;
 281
 282 static void
 283 fn_hash_select_default(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
 284 {
 285         int order, last_idx;
 286         struct hlist_node *node;
 287         struct fib_node *f;
 288         struct fib_info *fi = NULL;
 289         struct fib_info *last_resort;
 290         struct fn_hash *t = (struct fn_hash*)tb->tb_data;
 291         struct fn_zone *fz = t->fn_zones[0];
 292
 293         if (fz == NULL)
 294                 return;
 295
 296         last_idx = -1;
 297         last_resort = NULL;
 298         order = -1;
 299
 300         read_lock(&fib_hash_lock);
 301         hlist_for_each_entry(f, node, &fz->fz_hash[0], fn_hash) {
 302                 struct fib_alias *fa;
 303
 304                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
 305                         struct fib_info *next_fi = fa->fa_info;
 306
 307                         if (fa->fa_scope != res->scope ||
 308                             fa->fa_type != RTN_UNICAST)
 309                                 continue;
 310
 311                         if (next_fi->fib_priority > res->fi->fib_priority)
 312                                 break;
 313                         if (!next_fi->fib_nh[0].nh_gw ||
 314                             next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
 315                                 continue;
 316                         fa->fa_state |= FA_S_ACCESSED;
 317
 318                         if (fi == NULL) {
 319                                 if (next_fi != res->fi)
 320                                         break;
 321                         } else if (!fib_detect_death(fi, order, &last_resort,
 322                                                      &last_idx, &fn_hash_last_dflt)) {
 323                                 if (res->fi)
 324                                         fib_info_put(res->fi);
 325                                 res->fi = fi;
 326                                 atomic_inc(&fi->fib_clntref);
 327                                 fn_hash_last_dflt = order;
 328                                 goto out;
 329                         }
 330                         fi = next_fi;
 331                         order++;
 332                 }
 333         }
 334
 335         if (order <= 0 || fi == NULL) {
 336                 fn_hash_last_dflt = -1;
 337                 goto out;
 338         }
 339
 340         if (!fib_detect_death(fi, order, &last_resort, &last_idx, &fn_hash_last_dflt)) {
 341                 if (res->fi)
 342                         fib_info_put(res->fi);
 343                 res->fi = fi;
 344                 atomic_inc(&fi->fib_clntref);
 345                 fn_hash_last_dflt = order;
 346                 goto out;
 347         }
 348
 349         if (last_idx >= 0) {
 350                 if (res->fi)
 351                         fib_info_put(res->fi);
 352                 res->fi = last_resort;
 353                 if (last_resort)
 354                         atomic_inc(&last_resort->fib_clntref);
 355         }
 356         fn_hash_last_dflt = last_idx;
 357 out:
 358         read_unlock(&fib_hash_lock);
 359 }
 360
 361 /* Insert node F to FZ. */
 362 static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
 363 {
 364         struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
 365
 366         hlist_add_head(&f->fn_hash, head);
 367 }
 368
 369 /* Return the node in FZ matching KEY. */
 370 static struct fib_node *fib_find_node(struct fn_zone *fz, u32 key)
 371 {
 372         struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)];
 373         struct hlist_node *node;
 374         struct fib_node *f;
 375
 376         hlist_for_each_entry(f, node, head, fn_hash) {
 377                 if (f->fn_key == key)
 378                         return f;
 379         }
 380
 381         return NULL;
 382 }
 383
 384 static int
 385 fn_hash_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
 386                struct nlmsghdr *n, struct netlink_skb_parms *req)
 387 {
 388         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
 389         struct fib_node *new_f, *f;
 390         struct fib_alias *fa, *new_fa;
 391         struct fn_zone *fz;
 392         struct fib_info *fi;
 393         int z = r->rtm_dst_len;
 394         int type = r->rtm_type;
 395         u8 tos = r->rtm_tos;
 396         u32 key;
 397         int err;
 398
 399         if (z > 32)
 400                 return -EINVAL;
 401         fz = table->fn_zones[z];
 402         if (!fz && !(fz = fn_new_zone(table, z)))
 403                 return -ENOBUFS;
 404
 405         key = 0;
 406         if (rta->rta_dst) {
 407                 u32 dst;
 408                 memcpy(&dst, rta->rta_dst, 4);
 409                 if (dst & ~FZ_MASK(fz))
 410                         return -EINVAL;
 411                 key = fz_key(dst, fz);
 412         }
 413
 414         if  ((fi = fib_create_info(r, rta, n, &err)) == NULL)
 415                 return err;
 416
 417         if (fz->fz_nent > (fz->fz_divisor<<1) &&
 418             fz->fz_divisor < FZ_MAX_DIVISOR &&
 419             (z==32 || (1<<z) > fz->fz_divisor))
 420                 fn_rehash_zone(fz);
 421
 422         f = fib_find_node(fz, key);
 423
 424         if (!f)
 425                 fa = NULL;
 426         else
 427                 fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
 428
 429         /* Now fa, if non-NULL, points to the first fib alias
 430          * with the same keys [prefix,tos,priority], if such key already
 431          * exists or to the node before which we will insert new one.
 432          *
 433          * If fa is NULL, we will need to allocate a new one and
 434          * insert to the head of f.
 435          *
 436          * If f is NULL, no fib node matched the destination key
 437          * and we need to allocate a new one of those as well.
 438          */
 439
 440         if (fa && fa->fa_tos == tos &&
 441             fa->fa_info->fib_priority == fi->fib_priority) {
 442                 struct fib_alias *fa_orig;
 443
 444                 err = -EEXIST;
 445                 if (n->nlmsg_flags & NLM_F_EXCL)
 446                         goto out;
 447
 448                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 449                         struct fib_info *fi_drop;
 450                         u8 state;
 451
 452                         write_lock_bh(&fib_hash_lock);
 453                         fi_drop = fa->fa_info;
 454                         fa->fa_info = fi;
 455                         fa->fa_type = type;
 456                         fa->fa_scope = r->rtm_scope;
 457                         state = fa->fa_state;
 458                         fa->fa_state &= ~FA_S_ACCESSED;
 459                         fib_hash_genid++;
 460                         write_unlock_bh(&fib_hash_lock);
 461
 462                         fib_release_info(fi_drop);
 463                         if (state & FA_S_ACCESSED)
 464                                 rt_cache_flush(-1);
 465                         return 0;
 466                 }
 467
 468                 /* Error if we find a perfect match which
 469                  * uses the same scope, type, and nexthop
 470                  * information.
 471                  */
 472                 fa_orig = fa;
 473                 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
 474                 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
 475                         if (fa->fa_tos != tos)
 476                                 break;
 477                         if (fa->fa_info->fib_priority != fi->fib_priority)
 478                                 break;
 479                         if (fa->fa_type == type &&
 480                             fa->fa_scope == r->rtm_scope &&
 481                             fa->fa_info == fi)
 482                                 goto out;
 483                 }
 484                 if (!(n->nlmsg_flags & NLM_F_APPEND))
 485                         fa = fa_orig;
 486         }
 487
 488         err = -ENOENT;
 489         if (!(n->nlmsg_flags&NLM_F_CREATE))
 490                 goto out;
 491
 492         err = -ENOBUFS;
 493         new_fa = kmem_cache_alloc(fn_alias_kmem, SLAB_KERNEL);
 494         if (new_fa == NULL)
 495                 goto out;
 496
 497         new_f = NULL;
 498         if (!f) {
 499                 new_f = kmem_cache_alloc(fn_hash_kmem, SLAB_KERNEL);
 500                 if (new_f == NULL)
 501                         goto out_free_new_fa;
 502
 503                 INIT_HLIST_NODE(&new_f->fn_hash);
 504                 INIT_LIST_HEAD(&new_f->fn_alias);
 505                 new_f->fn_key = key;
 506                 f = new_f;
 507         }
 508
 509         new_fa->fa_info = fi;
 510         new_fa->fa_tos = tos;
 511         new_fa->fa_type = type;
 512         new_fa->fa_scope = r->rtm_scope;
 513         new_fa->fa_state = 0;
 514
 515         /*
 516          * Insert new entry to the list.
 517          */
 518
 519         write_lock_bh(&fib_hash_lock);
 520         if (new_f)
 521                 fib_insert_node(fz, new_f);
 522         list_add_tail(&new_fa->fa_list,
 523                  (fa ? &fa->fa_list : &f->fn_alias));
 524         fib_hash_genid++;
 525         write_unlock_bh(&fib_hash_lock);
 526
 527         if (new_f)
 528                 fz->fz_nent++;
 529         rt_cache_flush(-1);
 530
 531         rtmsg_fib(RTM_NEWROUTE, key, new_fa, z, tb->tb_id, n, req);
 532         return 0;
 533
 534 out_free_new_fa:
 535         kmem_cache_free(fn_alias_kmem, new_fa);
 536 out:
 537         fib_release_info(fi);
 538         return err;
 539 }
 540
 541
 542 static int
 543 fn_hash_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
 544                struct nlmsghdr *n, struct netlink_skb_parms *req)
 545 {
 546         struct fn_hash *table = (struct fn_hash*)tb->tb_data;
 547         struct fib_node *f;
 548         struct fib_alias *fa, *fa_to_delete;
 549         int z = r->rtm_dst_len;
 550         struct fn_zone *fz;
 551         u32 key;
 552         u8 tos = r->rtm_tos;
 553
 554         if (z > 32)
 555                 return -EINVAL;
 556         if ((fz  = table->fn_zones[z]) == NULL)
 557                 return -ESRCH;
 558
 559         key = 0;
 560         if (rta->rta_dst) {
 561                 u32 dst;
 562                 memcpy(&dst, rta->rta_dst, 4);
 563                 if (dst & ~FZ_MASK(fz))
 564                         return -EINVAL;
 565                 key = fz_key(dst, fz);
 566         }
 567
 568         f = fib_find_node(fz, key);
 569
 570         if (!f)
 571                 fa = NULL;
 572         else
 573                 fa = fib_find_alias(&f->fn_alias, tos, 0);
 574         if (!fa)
 575                 return -ESRCH;
 576
 577         fa_to_delete = NULL;
 578         fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
 579         list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
 580                 struct fib_info *fi = fa->fa_info;
 581
 582                 if (fa->fa_tos != tos)
 583                         break;
 584
 585                 if ((!r->rtm_type ||
 586                      fa->fa_type == r->rtm_type) &&
 587                     (r->rtm_scope == RT_SCOPE_NOWHERE ||
 588                      fa->fa_scope == r->rtm_scope) &&
 589                     (!r->rtm_protocol ||
 590                      fi->fib_protocol == r->rtm_protocol) &&
 591                     fib_nh_match(r, n, rta, fi) == 0) {
 592                         fa_to_delete = fa;
 593                         break;
 594                 }
 595         }
 596
 597         if (fa_to_delete) {
 598                 int kill_fn;
 599
 600                 fa = fa_to_delete;
 601                 rtmsg_fib(RTM_DELROUTE, key, fa, z, tb->tb_id, n, req);
 602
 603                 kill_fn = 0;
 604                 write_lock_bh(&fib_hash_lock);
 605                 list_del(&fa->fa_list);
 606                 if (list_empty(&f->fn_alias)) {
 607                         hlist_del(&f->fn_hash);
 608                         kill_fn = 1;
 609                 }
 610                 fib_hash_genid++;
 611                 write_unlock_bh(&fib_hash_lock);
 612
 613                 if (fa->fa_state & FA_S_ACCESSED)
 614                         rt_cache_flush(-1);
 615                 fn_free_alias(fa);
 616                 if (kill_fn) {
 617                         fn_free_node(f);
 618                         fz->fz_nent--;
 619                 }
 620
 621                 return 0;
 622         }
 623         return -ESRCH;
 624 }
 625
 626 static int fn_flush_list(struct fn_zone *fz, int idx)
 627 {
 628         struct hlist_head *head = &fz->fz_hash[idx];
 629         struct hlist_node *node, *n;
 630         struct fib_node *f;
 631         int found = 0;
 632
 633         hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
 634                 struct fib_alias *fa, *fa_node;
 635                 int kill_f;
 636
 637                 kill_f = 0;
 638                 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
 639                         struct fib_info *fi = fa->fa_info;
 640
 641                         if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
 642                                 write_lock_bh(&fib_hash_lock);
 643                                 list_del(&fa->fa_list);
 644                                 if (list_empty(&f->fn_alias)) {
 645                                         hlist_del(&f->fn_hash);
 646                                         kill_f = 1;
 647                                 }
 648                                 fib_hash_genid++;
 649                                 write_unlock_bh(&fib_hash_lock);
 650
 651                                 fn_free_alias(fa);
 652                                 found++;
 653                         }
 654                 }
 655                 if (kill_f) {
 656                         fn_free_node(f);
 657                         fz->fz_nent--;
 658                 }
 659         }
 660         return found;
 661 }
 662
 663 static int fn_hash_flush(struct fib_table *tb)
 664 {
 665         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
 666         struct fn_zone *fz;
 667         int found = 0;
 668
 669         for (fz = table->fn_zone_list; fz; fz = fz->fz_next) {
 670                 int i;
 671
 672                 for (i = fz->fz_divisor - 1; i >= 0; i--)
 673                         found += fn_flush_list(fz, i);
 674         }
 675         return found;
 676 }
 677
 678
 679 static inline int
 680 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
 681                      struct fib_table *tb,
 682                      struct fn_zone *fz,
 683                      struct hlist_head *head)
 684 {
 685         struct hlist_node *node;
 686         struct fib_node *f;
 687         int i, s_i;
 688
 689         s_i = cb->args[3];
 690         i = 0;
 691         hlist_for_each_entry(f, node, head, fn_hash) {
 692                 struct fib_alias *fa;
 693
 694                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
 695                         if (i < s_i)
 696                                 goto next;
 697
 698                         if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 699                                           cb->nlh->nlmsg_seq,
 700                                           RTM_NEWROUTE,
 701                                           tb->tb_id,
 702                                           fa->fa_type,
 703                                           fa->fa_scope,
 704                                           &f->fn_key,
 705                                           fz->fz_order,
 706                                           fa->fa_tos,
 707                                           fa->fa_info,
 708                                           NLM_F_MULTI) < 0) {
 709                                 cb->args[3] = i;
 710                                 return -1;
 711                         }
 712                 next:
 713                         i++;
 714                 }
 715         }
 716         cb->args[3] = i;
 717         return skb->len;
 718 }
 719
 720 static inline int
 721 fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
 722                    struct fib_table *tb,
 723                    struct fn_zone *fz)
 724 {
 725         int h, s_h;
 726
 727         s_h = cb->args[2];
 728         for (h=0; h < fz->fz_divisor; h++) {
 729                 if (h < s_h) continue;
 730                 if (h > s_h)
 731                         memset(&cb->args[3], 0,
 732                                sizeof(cb->args) - 3*sizeof(cb->args[0]));
 733                 if (fz->fz_hash == NULL ||
 734                     hlist_empty(&fz->fz_hash[h]))
 735                         continue;
 736                 if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h])<0) {
 737                         cb->args[2] = h;
 738                         return -1;
 739                 }
 740         }
 741         cb->args[2] = h;
 742         return skb->len;
 743 }
 744
 745 static int fn_hash_dump(struct fib_table *tb, struct sk_buff *skb, struct netlink_callback *cb)
 746 {
 747         int m, s_m;
 748         struct fn_zone *fz;
 749         struct fn_hash *table = (struct fn_hash*)tb->tb_data;
 750
 751         s_m = cb->args[1];
 752         read_lock(&fib_hash_lock);
 753         for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) {
 754                 if (m < s_m) continue;
 755                 if (m > s_m)
 756                         memset(&cb->args[2], 0,
 757                                sizeof(cb->args) - 2*sizeof(cb->args[0]));
 758                 if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
 759                         cb->args[1] = m;
 760                         read_unlock(&fib_hash_lock);
 761                         return -1;
 762                 }
 763         }
 764         read_unlock(&fib_hash_lock);
 765         cb->args[1] = m;
 766         return skb->len;
 767 }
 768
 769 #ifdef CONFIG_IP_MULTIPLE_TABLES
 770 struct fib_table * fib_hash_init(int id)
 771 #else
 772 struct fib_table * __init fib_hash_init(int id)
 773 #endif
 774 {
 775         struct fib_table *tb;
 776
 777         if (fn_hash_kmem == NULL)
 778                 fn_hash_kmem = kmem_cache_create("ip_fib_hash",
 779                                                  sizeof(struct fib_node),
 780                                                  0, SLAB_HWCACHE_ALIGN,
 781                                                  NULL, NULL);
 782
 783         if (fn_alias_kmem == NULL)
 784                 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
 785                                                   sizeof(struct fib_alias),
 786                                                   0, SLAB_HWCACHE_ALIGN,
 787                                                   NULL, NULL);
 788
 789         tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash),
 790                      GFP_KERNEL);
 791         if (tb == NULL)
 792                 return NULL;
 793
 794         tb->tb_id = id;
 795         tb->tb_lookup = fn_hash_lookup;
 796         tb->tb_insert = fn_hash_insert;
 797         tb->tb_delete = fn_hash_delete;
 798         tb->tb_flush = fn_hash_flush;
 799         tb->tb_select_default = fn_hash_select_default;
 800         tb->tb_dump = fn_hash_dump;
 801         memset(tb->tb_data, 0, sizeof(struct fn_hash));
 802         return tb;
 803 }
 804
 805 /* ------------------------------------------------------------------------ */
 806 #ifdef CONFIG_PROC_FS
 807
 808 struct fib_iter_state {
 809         struct fn_zone  *zone;
 810         int             bucket;
 811         struct hlist_head *hash_head;
 812         struct fib_node *fn;
 813         struct fib_alias *fa;
 814         loff_t pos;
 815         unsigned int genid;
 816         int valid;
 817 };
 818
 819 static struct fib_alias *fib_get_first(struct seq_file *seq)
 820 {
 821         struct fib_iter_state *iter = seq->private;
 822         struct fn_hash *table = (struct fn_hash *) ip_fib_main_table->tb_data;
 823
 824         iter->bucket    = 0;
 825         iter->hash_head = NULL;
 826         iter->fn        = NULL;
 827         iter->fa        = NULL;
 828         iter->pos       = 0;
 829         iter->genid     = fib_hash_genid;
 830         iter->valid     = 1;
 831
 832         for (iter->zone = table->fn_zone_list; iter->zone;
 833              iter->zone = iter->zone->fz_next) {
 834                 int maxslot;
 835
 836                 if (!iter->zone->fz_nent)
 837                         continue;
 838
 839                 iter->hash_head = iter->zone->fz_hash;
 840                 maxslot = iter->zone->fz_divisor;
 841
 842                 for (iter->bucket = 0; iter->bucket < maxslot;
 843                      ++iter->bucket, ++iter->hash_head) {
 844                         struct hlist_node *node;
 845                         struct fib_node *fn;
 846
 847                         hlist_for_each_entry(fn,node,iter->hash_head,fn_hash) {
 848                                 struct fib_alias *fa;
 849
 850                                 list_for_each_entry(fa,&fn->fn_alias,fa_list) {
 851                                         iter->fn = fn;
 852                                         iter->fa = fa;
 853                                         goto out;
 854                                 }
 855                         }
 856                 }
 857         }
 858 out:
 859         return iter->fa;
 860 }
 861
 862 static struct fib_alias *fib_get_next(struct seq_file *seq)
 863 {
 864         struct fib_iter_state *iter = seq->private;
 865         struct fib_node *fn;
 866         struct fib_alias *fa;
 867
 868         /* Advance FA, if any. */
 869         fn = iter->fn;
 870         fa = iter->fa;
 871         if (fa) {
 872                 BUG_ON(!fn);
 873                 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
 874                         iter->fa = fa;
 875                         goto out;
 876                 }
 877         }
 878
 879         fa = iter->fa = NULL;
 880
 881         /* Advance FN. */
 882         if (fn) {
 883                 struct hlist_node *node = &fn->fn_hash;
 884                 hlist_for_each_entry_continue(fn, node, fn_hash) {
 885                         iter->fn = fn;
 886
 887                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
 888                                 iter->fa = fa;
 889                                 goto out;
 890                         }
 891                 }
 892         }
 893
 894         fn = iter->fn = NULL;
 895
 896         /* Advance hash chain. */
 897         if (!iter->zone)
 898                 goto out;
 899
 900         for (;;) {
 901                 struct hlist_node *node;
 902                 int maxslot;
 903
 904                 maxslot = iter->zone->fz_divisor;
 905
 906                 while (++iter->bucket < maxslot) {
 907                         iter->hash_head++;
 908
 909                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
 910                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
 911                                         iter->fn = fn;
 912                                         iter->fa = fa;
 913                                         goto out;
 914                                 }
 915                         }
 916                 }
 917
 918                 iter->zone = iter->zone->fz_next;
 919
 920                 if (!iter->zone)
 921                         goto out;
 922
 923                 iter->bucket = 0;
 924                 iter->hash_head = iter->zone->fz_hash;
 925
 926                 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
 927                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
 928                                 iter->fn = fn;
 929                                 iter->fa = fa;
 930                                 goto out;
 931                         }
 932                 }
 933         }
 934 out:
 935         iter->pos++;
 936         return fa;
 937 }
 938
 939 static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
 940 {
 941         struct fib_iter_state *iter = seq->private;
 942         struct fib_alias *fa;
 943
 944         if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
 945                 fa   = iter->fa;
 946                 pos -= iter->pos;
 947         } else
 948                 fa = fib_get_first(seq);
 949
 950         if (fa)
 951                 while (pos && (fa = fib_get_next(seq)))
 952                         --pos;
 953         return pos ? NULL : fa;
 954 }
 955
 956 static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
 957 {
 958         void *v = NULL;
 959
 960         read_lock(&fib_hash_lock);
 961         if (ip_fib_main_table)
 962                 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 963         return v;
 964 }
 965
 966 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 967 {
 968         ++*pos;
 969         return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
 970 }
 971
 972 static void fib_seq_stop(struct seq_file *seq, void *v)
 973 {
 974         read_unlock(&fib_hash_lock);
 975 }
 976
 977 static unsigned fib_flag_trans(int type, u32 mask, struct fib_info *fi)
 978 {
 979         static const unsigned type2flags[RTN_MAX + 1] = {
 980                 [7] = RTF_REJECT, [8] = RTF_REJECT,
 981         };
 982         unsigned flags = type2flags[type];
 983
 984         if (fi && fi->fib_nh->nh_gw)
 985                 flags |= RTF_GATEWAY;
 986         if (mask == 0xFFFFFFFF)
 987                 flags |= RTF_HOST;
 988         flags |= RTF_UP;
 989         return flags;
 990 }
 991
 992 extern int dev_in_nx_info(struct net_device *, struct nx_info *);
 993
 994 /*
 995  *      This outputs /proc/net/route.
 996  *
 997  *      It always works in backward compatibility mode.
 998  *      The format of the file is not supposed to be changed.
 999  */
1000 static int fib_seq_show(struct seq_file *seq, void *v)
1001 {
1002         struct fib_iter_state *iter;
1003         char bf[128];
1004         u32 prefix, mask;
1005         unsigned flags;
1006         struct fib_node *f;
1007         struct fib_alias *fa;
1008         struct fib_info *fi;
1009
1010         if (v == SEQ_START_TOKEN) {
1011                 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
1012                            "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
1013                            "\tWindow\tIRTT");
1014                 goto out;
1015         }
1016
1017         iter    = seq->private;
1018         f       = iter->fn;
1019         fa      = iter->fa;
1020         fi      = fa->fa_info;
1021         prefix  = f->fn_key;
1022         mask    = FZ_MASK(iter->zone);
1023         flags   = fib_flag_trans(fa->fa_type, mask, fi);
1024         if (fi && (!vx_flags(VXF_HIDE_NETIF, 0) ||
1025                 dev_in_nx_info(fi->fib_dev, current->nx_info)))
1026                 snprintf(bf, sizeof(bf),
1027                          "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1028                          fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1029                          fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1030                          mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1031                          fi->fib_window,
1032                          fi->fib_rtt >> 3);
1033         else
1034                 snprintf(bf, sizeof(bf),
1035                          "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1036                          prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0);
1037         seq_printf(seq, "%-127s\n", bf);
1038 out:
1039         return 0;
1040 }
1041
1042 static struct seq_operations fib_seq_ops = {
1043         .start  = fib_seq_start,
1044         .next   = fib_seq_next,
1045         .stop   = fib_seq_stop,
1046         .show   = fib_seq_show,
1047 };
1048
1049 static int fib_seq_open(struct inode *inode, struct file *file)
1050 {
1051         struct seq_file *seq;
1052         int rc = -ENOMEM;
1053         struct fib_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
1054
1055         if (!s)
1056                 goto out;
1057
1058         rc = seq_open(file, &fib_seq_ops);
1059         if (rc)
1060                 goto out_kfree;
1061
1062         seq          = file->private_data;
1063         seq->private = s;
1064         memset(s, 0, sizeof(*s));
1065 out:
1066         return rc;
1067 out_kfree:
1068         kfree(s);
1069         goto out;
1070 }
1071
1072 static struct file_operations fib_seq_fops = {
1073         .owner          = THIS_MODULE,
1074         .open           = fib_seq_open,
1075         .read           = seq_read,
1076         .llseek         = seq_lseek,
1077         .release        = seq_release_private,
1078 };
1079
1080 int __init fib_proc_init(void)
1081 {
1082         if (!proc_net_fops_create("route", S_IRUGO, &fib_seq_fops))
1083                 return -ENOMEM;
1084         return 0;
1085 }
1086
1087 void __init fib_proc_exit(void)
1088 {
1089         proc_net_remove("route");
1090 }
1091 #endif /* CONFIG_PROC_FS */