Pileus Git - ~andy/linux/blob - net/core/neighbour.c

   1 /*
   2  *      Generic address resolution entity
   3  *
   4  *      Authors:
   5  *      Pedro Roque             <roque@di.fc.ul.pt>
   6  *      Alexey Kuznetsov        <kuznet@ms2.inr.ac.ru>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  *
  13  *      Fixes:
  14  *      Vitaly E. Lavrov        releasing NULL neighbor in neigh_add.
  15  *      Harald Welte            Add neighbour cache statistics like rtstat
  16  */
  17
  18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  19
  20 #include <linux/slab.h>
  21 #include <linux/types.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/socket.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/proc_fs.h>
  27 #ifdef CONFIG_SYSCTL
  28 #include <linux/sysctl.h>
  29 #endif
  30 #include <linux/times.h>
  31 #include <net/net_namespace.h>
  32 #include <net/neighbour.h>
  33 #include <net/dst.h>
  34 #include <net/sock.h>
  35 #include <net/netevent.h>
  36 #include <net/netlink.h>
  37 #include <linux/rtnetlink.h>
  38 #include <linux/random.h>
  39 #include <linux/string.h>
  40 #include <linux/log2.h>
  41 #include <linux/inetdevice.h>
  42 #include <net/addrconf.h>
  43
  44 #define DEBUG
  45 #define NEIGH_DEBUG 1
  46 #define neigh_dbg(level, fmt, ...)              \
  47 do {                                            \
  48         if (level <= NEIGH_DEBUG)               \
  49                 pr_debug(fmt, ##__VA_ARGS__);   \
  50 } while (0)
  51
  52 #define PNEIGH_HASHMASK         0xF
  53
  54 static void neigh_timer_handler(unsigned long arg);
  55 static void __neigh_notify(struct neighbour *n, int type, int flags);
  56 static void neigh_update_notify(struct neighbour *neigh);
  57 static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
  58
  59 static struct neigh_table *neigh_tables;
  60 #ifdef CONFIG_PROC_FS
  61 static const struct file_operations neigh_stat_seq_fops;
  62 #endif
  63
  64 /*
  65    Neighbour hash table buckets are protected with rwlock tbl->lock.
  66
  67    - All the scans/updates to hash buckets MUST be made under this lock.
  68    - NOTHING clever should be made under this lock: no callbacks
  69      to protocol backends, no attempts to send something to network.
  70      It will result in deadlocks, if backend/driver wants to use neighbour
  71      cache.
  72    - If the entry requires some non-trivial actions, increase
  73      its reference count and release table lock.
  74
  75    Neighbour entries are protected:
  76    - with reference count.
  77    - with rwlock neigh->lock
  78
  79    Reference count prevents destruction.
  80
  81    neigh->lock mainly serializes ll address data and its validity state.
  82    However, the same lock is used to protect another entry fields:
  83     - timer
  84     - resolution queue
  85
  86    Again, nothing clever shall be made under neigh->lock,
  87    the most complicated procedure, which we allow is dev->hard_header.
  88    It is supposed, that dev->hard_header is simplistic and does
  89    not make callbacks to neighbour tables.
  90
  91    The last lock is neigh_tbl_lock. It is pure SMP lock, protecting
  92    list of neighbour tables. This list is used only in process context,
  93  */
  94
  95 static DEFINE_RWLOCK(neigh_tbl_lock);
  96
  97 static int neigh_blackhole(struct neighbour *neigh, struct sk_buff *skb)
  98 {
  99         kfree_skb(skb);
 100         return -ENETDOWN;
 101 }
 102
 103 static void neigh_cleanup_and_release(struct neighbour *neigh)
 104 {
 105         if (neigh->parms->neigh_cleanup)
 106                 neigh->parms->neigh_cleanup(neigh);
 107
 108         __neigh_notify(neigh, RTM_DELNEIGH, 0);
 109         neigh_release(neigh);
 110 }
 111
 112 /*
 113  * It is random distribution in the interval (1/2)*base...(3/2)*base.
 114  * It corresponds to default IPv6 settings and is not overridable,
 115  * because it is really reasonable choice.
 116  */
 117
 118 unsigned long neigh_rand_reach_time(unsigned long base)
 119 {
 120         return base ? (net_random() % base) + (base >> 1) : 0;
 121 }
 122 EXPORT_SYMBOL(neigh_rand_reach_time);
 123
 124
 125 static int neigh_forced_gc(struct neigh_table *tbl)
 126 {
 127         int shrunk = 0;
 128         int i;
 129         struct neigh_hash_table *nht;
 130
 131         NEIGH_CACHE_STAT_INC(tbl, forced_gc_runs);
 132
 133         write_lock_bh(&tbl->lock);
 134         nht = rcu_dereference_protected(tbl->nht,
 135                                         lockdep_is_held(&tbl->lock));
 136         for (i = 0; i < (1 << nht->hash_shift); i++) {
 137                 struct neighbour *n;
 138                 struct neighbour __rcu **np;
 139
 140                 np = &nht->hash_buckets[i];
 141                 while ((n = rcu_dereference_protected(*np,
 142                                         lockdep_is_held(&tbl->lock))) != NULL) {
 143                         /* Neighbour record may be discarded if:
 144                          * - nobody refers to it.
 145                          * - it is not permanent
 146                          */
 147                         write_lock(&n->lock);
 148                         if (atomic_read(&n->refcnt) == 1 &&
 149                             !(n->nud_state & NUD_PERMANENT)) {
 150                                 rcu_assign_pointer(*np,
 151                                         rcu_dereference_protected(n->next,
 152                                                   lockdep_is_held(&tbl->lock)));
 153                                 n->dead = 1;
 154                                 shrunk  = 1;
 155                                 write_unlock(&n->lock);
 156                                 neigh_cleanup_and_release(n);
 157                                 continue;
 158                         }
 159                         write_unlock(&n->lock);
 160                         np = &n->next;
 161                 }
 162         }
 163
 164         tbl->last_flush = jiffies;
 165
 166         write_unlock_bh(&tbl->lock);
 167
 168         return shrunk;
 169 }
 170
 171 static void neigh_add_timer(struct neighbour *n, unsigned long when)
 172 {
 173         neigh_hold(n);
 174         if (unlikely(mod_timer(&n->timer, when))) {
 175                 printk("NEIGH: BUG, double timer add, state is %x\n",
 176                        n->nud_state);
 177                 dump_stack();
 178         }
 179 }
 180
 181 static int neigh_del_timer(struct neighbour *n)
 182 {
 183         if ((n->nud_state & NUD_IN_TIMER) &&
 184             del_timer(&n->timer)) {
 185                 neigh_release(n);
 186                 return 1;
 187         }
 188         return 0;
 189 }
 190
 191 static void pneigh_queue_purge(struct sk_buff_head *list)
 192 {
 193         struct sk_buff *skb;
 194
 195         while ((skb = skb_dequeue(list)) != NULL) {
 196                 dev_put(skb->dev);
 197                 kfree_skb(skb);
 198         }
 199 }
 200
 201 static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev)
 202 {
 203         int i;
 204         struct neigh_hash_table *nht;
 205
 206         nht = rcu_dereference_protected(tbl->nht,
 207                                         lockdep_is_held(&tbl->lock));
 208
 209         for (i = 0; i < (1 << nht->hash_shift); i++) {
 210                 struct neighbour *n;
 211                 struct neighbour __rcu **np = &nht->hash_buckets[i];
 212
 213                 while ((n = rcu_dereference_protected(*np,
 214                                         lockdep_is_held(&tbl->lock))) != NULL) {
 215                         if (dev && n->dev != dev) {
 216                                 np = &n->next;
 217                                 continue;
 218                         }
 219                         rcu_assign_pointer(*np,
 220                                    rcu_dereference_protected(n->next,
 221                                                 lockdep_is_held(&tbl->lock)));
 222                         write_lock(&n->lock);
 223                         neigh_del_timer(n);
 224                         n->dead = 1;
 225
 226                         if (atomic_read(&n->refcnt) != 1) {
 227                                 /* The most unpleasant situation.
 228                                    We must destroy neighbour entry,
 229                                    but someone still uses it.
 230
 231                                    The destroy will be delayed until
 232                                    the last user releases us, but
 233                                    we must kill timers etc. and move
 234                                    it to safe state.
 235                                  */
 236                                 __skb_queue_purge(&n->arp_queue);
 237                                 n->arp_queue_len_bytes = 0;
 238                                 n->output = neigh_blackhole;
 239                                 if (n->nud_state & NUD_VALID)
 240                                         n->nud_state = NUD_NOARP;
 241                                 else
 242                                         n->nud_state = NUD_NONE;
 243                                 neigh_dbg(2, "neigh %p is stray\n", n);
 244                         }
 245                         write_unlock(&n->lock);
 246                         neigh_cleanup_and_release(n);
 247                 }
 248         }
 249 }
 250
 251 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev)
 252 {
 253         write_lock_bh(&tbl->lock);
 254         neigh_flush_dev(tbl, dev);
 255         write_unlock_bh(&tbl->lock);
 256 }
 257 EXPORT_SYMBOL(neigh_changeaddr);
 258
 259 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 260 {
 261         write_lock_bh(&tbl->lock);
 262         neigh_flush_dev(tbl, dev);
 263         pneigh_ifdown(tbl, dev);
 264         write_unlock_bh(&tbl->lock);
 265
 266         del_timer_sync(&tbl->proxy_timer);
 267         pneigh_queue_purge(&tbl->proxy_queue);
 268         return 0;
 269 }
 270 EXPORT_SYMBOL(neigh_ifdown);
 271
 272 static struct neighbour *neigh_alloc(struct neigh_table *tbl, struct net_device *dev)
 273 {
 274         struct neighbour *n = NULL;
 275         unsigned long now = jiffies;
 276         int entries;
 277
 278         entries = atomic_inc_return(&tbl->entries) - 1;
 279         if (entries >= tbl->gc_thresh3 ||
 280             (entries >= tbl->gc_thresh2 &&
 281              time_after(now, tbl->last_flush + 5 * HZ))) {
 282                 if (!neigh_forced_gc(tbl) &&
 283                     entries >= tbl->gc_thresh3)
 284                         goto out_entries;
 285         }
 286
 287         n = kzalloc(tbl->entry_size + dev->neigh_priv_len, GFP_ATOMIC);
 288         if (!n)
 289                 goto out_entries;
 290
 291         __skb_queue_head_init(&n->arp_queue);
 292         rwlock_init(&n->lock);
 293         seqlock_init(&n->ha_lock);
 294         n->updated        = n->used = now;
 295         n->nud_state      = NUD_NONE;
 296         n->output         = neigh_blackhole;
 297         seqlock_init(&n->hh.hh_lock);
 298         n->parms          = neigh_parms_clone(&tbl->parms);
 299         setup_timer(&n->timer, neigh_timer_handler, (unsigned long)n);
 300
 301         NEIGH_CACHE_STAT_INC(tbl, allocs);
 302         n->tbl            = tbl;
 303         atomic_set(&n->refcnt, 1);
 304         n->dead           = 1;
 305 out:
 306         return n;
 307
 308 out_entries:
 309         atomic_dec(&tbl->entries);
 310         goto out;
 311 }
 312
 313 static void neigh_get_hash_rnd(u32 *x)
 314 {
 315         get_random_bytes(x, sizeof(*x));
 316         *x |= 1;
 317 }
 318
 319 static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift)
 320 {
 321         size_t size = (1 << shift) * sizeof(struct neighbour *);
 322         struct neigh_hash_table *ret;
 323         struct neighbour __rcu **buckets;
 324         int i;
 325
 326         ret = kmalloc(sizeof(*ret), GFP_ATOMIC);
 327         if (!ret)
 328                 return NULL;
 329         if (size <= PAGE_SIZE)
 330                 buckets = kzalloc(size, GFP_ATOMIC);
 331         else
 332                 buckets = (struct neighbour __rcu **)
 333                           __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
 334                                            get_order(size));
 335         if (!buckets) {
 336                 kfree(ret);
 337                 return NULL;
 338         }
 339         ret->hash_buckets = buckets;
 340         ret->hash_shift = shift;
 341         for (i = 0; i < NEIGH_NUM_HASH_RND; i++)
 342                 neigh_get_hash_rnd(&ret->hash_rnd[i]);
 343         return ret;
 344 }
 345
 346 static void neigh_hash_free_rcu(struct rcu_head *head)
 347 {
 348         struct neigh_hash_table *nht = container_of(head,
 349                                                     struct neigh_hash_table,
 350                                                     rcu);
 351         size_t size = (1 << nht->hash_shift) * sizeof(struct neighbour *);
 352         struct neighbour __rcu **buckets = nht->hash_buckets;
 353
 354         if (size <= PAGE_SIZE)
 355                 kfree(buckets);
 356         else
 357                 free_pages((unsigned long)buckets, get_order(size));
 358         kfree(nht);
 359 }
 360
 361 static struct neigh_hash_table *neigh_hash_grow(struct neigh_table *tbl,
 362                                                 unsigned long new_shift)
 363 {
 364         unsigned int i, hash;
 365         struct neigh_hash_table *new_nht, *old_nht;
 366
 367         NEIGH_CACHE_STAT_INC(tbl, hash_grows);
 368
 369         old_nht = rcu_dereference_protected(tbl->nht,
 370                                             lockdep_is_held(&tbl->lock));
 371         new_nht = neigh_hash_alloc(new_shift);
 372         if (!new_nht)
 373                 return old_nht;
 374
 375         for (i = 0; i < (1 << old_nht->hash_shift); i++) {
 376                 struct neighbour *n, *next;
 377
 378                 for (n = rcu_dereference_protected(old_nht->hash_buckets[i],
 379                                                    lockdep_is_held(&tbl->lock));
 380                      n != NULL;
 381                      n = next) {
 382                         hash = tbl->hash(n->primary_key, n->dev,
 383                                          new_nht->hash_rnd);
 384
 385                         hash >>= (32 - new_nht->hash_shift);
 386                         next = rcu_dereference_protected(n->next,
 387                                                 lockdep_is_held(&tbl->lock));
 388
 389                         rcu_assign_pointer(n->next,
 390                                            rcu_dereference_protected(
 391                                                 new_nht->hash_buckets[hash],
 392                                                 lockdep_is_held(&tbl->lock)));
 393                         rcu_assign_pointer(new_nht->hash_buckets[hash], n);
 394                 }
 395         }
 396
 397         rcu_assign_pointer(tbl->nht, new_nht);
 398         call_rcu(&old_nht->rcu, neigh_hash_free_rcu);
 399         return new_nht;
 400 }
 401
 402 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
 403                                struct net_device *dev)
 404 {
 405         struct neighbour *n;
 406         int key_len = tbl->key_len;
 407         u32 hash_val;
 408         struct neigh_hash_table *nht;
 409
 410         NEIGH_CACHE_STAT_INC(tbl, lookups);
 411
 412         rcu_read_lock_bh();
 413         nht = rcu_dereference_bh(tbl->nht);
 414         hash_val = tbl->hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
 415
 416         for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
 417              n != NULL;
 418              n = rcu_dereference_bh(n->next)) {
 419                 if (dev == n->dev && !memcmp(n->primary_key, pkey, key_len)) {
 420                         if (!atomic_inc_not_zero(&n->refcnt))
 421                                 n = NULL;
 422                         NEIGH_CACHE_STAT_INC(tbl, hits);
 423                         break;
 424                 }
 425         }
 426
 427         rcu_read_unlock_bh();
 428         return n;
 429 }
 430 EXPORT_SYMBOL(neigh_lookup);
 431
 432 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
 433                                      const void *pkey)
 434 {
 435         struct neighbour *n;
 436         int key_len = tbl->key_len;
 437         u32 hash_val;
 438         struct neigh_hash_table *nht;
 439
 440         NEIGH_CACHE_STAT_INC(tbl, lookups);
 441
 442         rcu_read_lock_bh();
 443         nht = rcu_dereference_bh(tbl->nht);
 444         hash_val = tbl->hash(pkey, NULL, nht->hash_rnd) >> (32 - nht->hash_shift);
 445
 446         for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
 447              n != NULL;
 448              n = rcu_dereference_bh(n->next)) {
 449                 if (!memcmp(n->primary_key, pkey, key_len) &&
 450                     net_eq(dev_net(n->dev), net)) {
 451                         if (!atomic_inc_not_zero(&n->refcnt))
 452                                 n = NULL;
 453                         NEIGH_CACHE_STAT_INC(tbl, hits);
 454                         break;
 455                 }
 456         }
 457
 458         rcu_read_unlock_bh();
 459         return n;
 460 }
 461 EXPORT_SYMBOL(neigh_lookup_nodev);
 462
 463 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
 464                                  struct net_device *dev, bool want_ref)
 465 {
 466         u32 hash_val;
 467         int key_len = tbl->key_len;
 468         int error;
 469         struct neighbour *n1, *rc, *n = neigh_alloc(tbl, dev);
 470         struct neigh_hash_table *nht;
 471
 472         if (!n) {
 473                 rc = ERR_PTR(-ENOBUFS);
 474                 goto out;
 475         }
 476
 477         memcpy(n->primary_key, pkey, key_len);
 478         n->dev = dev;
 479         dev_hold(dev);
 480
 481         /* Protocol specific setup. */
 482         if (tbl->constructor && (error = tbl->constructor(n)) < 0) {
 483                 rc = ERR_PTR(error);
 484                 goto out_neigh_release;
 485         }
 486
 487         if (dev->netdev_ops->ndo_neigh_construct) {
 488                 error = dev->netdev_ops->ndo_neigh_construct(n);
 489                 if (error < 0) {
 490                         rc = ERR_PTR(error);
 491                         goto out_neigh_release;
 492                 }
 493         }
 494
 495         /* Device specific setup. */
 496         if (n->parms->neigh_setup &&
 497             (error = n->parms->neigh_setup(n)) < 0) {
 498                 rc = ERR_PTR(error);
 499                 goto out_neigh_release;
 500         }
 501
 502         n->confirmed = jiffies - (NEIGH_VAR(n->parms, BASE_REACHABLE_TIME) << 1);
 503
 504         write_lock_bh(&tbl->lock);
 505         nht = rcu_dereference_protected(tbl->nht,
 506                                         lockdep_is_held(&tbl->lock));
 507
 508         if (atomic_read(&tbl->entries) > (1 << nht->hash_shift))
 509                 nht = neigh_hash_grow(tbl, nht->hash_shift + 1);
 510
 511         hash_val = tbl->hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
 512
 513         if (n->parms->dead) {
 514                 rc = ERR_PTR(-EINVAL);
 515                 goto out_tbl_unlock;
 516         }
 517
 518         for (n1 = rcu_dereference_protected(nht->hash_buckets[hash_val],
 519                                             lockdep_is_held(&tbl->lock));
 520              n1 != NULL;
 521              n1 = rcu_dereference_protected(n1->next,
 522                         lockdep_is_held(&tbl->lock))) {
 523                 if (dev == n1->dev && !memcmp(n1->primary_key, pkey, key_len)) {
 524                         if (want_ref)
 525                                 neigh_hold(n1);
 526                         rc = n1;
 527                         goto out_tbl_unlock;
 528                 }
 529         }
 530
 531         n->dead = 0;
 532         if (want_ref)
 533                 neigh_hold(n);
 534         rcu_assign_pointer(n->next,
 535                            rcu_dereference_protected(nht->hash_buckets[hash_val],
 536                                                      lockdep_is_held(&tbl->lock)));
 537         rcu_assign_pointer(nht->hash_buckets[hash_val], n);
 538         write_unlock_bh(&tbl->lock);
 539         neigh_dbg(2, "neigh %p is created\n", n);
 540         rc = n;
 541 out:
 542         return rc;
 543 out_tbl_unlock:
 544         write_unlock_bh(&tbl->lock);
 545 out_neigh_release:
 546         neigh_release(n);
 547         goto out;
 548 }
 549 EXPORT_SYMBOL(__neigh_create);
 550
 551 static u32 pneigh_hash(const void *pkey, int key_len)
 552 {
 553         u32 hash_val = *(u32 *)(pkey + key_len - 4);
 554         hash_val ^= (hash_val >> 16);
 555         hash_val ^= hash_val >> 8;
 556         hash_val ^= hash_val >> 4;
 557         hash_val &= PNEIGH_HASHMASK;
 558         return hash_val;
 559 }
 560
 561 static struct pneigh_entry *__pneigh_lookup_1(struct pneigh_entry *n,
 562                                               struct net *net,
 563                                               const void *pkey,
 564                                               int key_len,
 565                                               struct net_device *dev)
 566 {
 567         while (n) {
 568                 if (!memcmp(n->key, pkey, key_len) &&
 569                     net_eq(pneigh_net(n), net) &&
 570                     (n->dev == dev || !n->dev))
 571                         return n;
 572                 n = n->next;
 573         }
 574         return NULL;
 575 }
 576
 577 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl,
 578                 struct net *net, const void *pkey, struct net_device *dev)
 579 {
 580         int key_len = tbl->key_len;
 581         u32 hash_val = pneigh_hash(pkey, key_len);
 582
 583         return __pneigh_lookup_1(tbl->phash_buckets[hash_val],
 584                                  net, pkey, key_len, dev);
 585 }
 586 EXPORT_SYMBOL_GPL(__pneigh_lookup);
 587
 588 struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl,
 589                                     struct net *net, const void *pkey,
 590                                     struct net_device *dev, int creat)
 591 {
 592         struct pneigh_entry *n;
 593         int key_len = tbl->key_len;
 594         u32 hash_val = pneigh_hash(pkey, key_len);
 595
 596         read_lock_bh(&tbl->lock);
 597         n = __pneigh_lookup_1(tbl->phash_buckets[hash_val],
 598                               net, pkey, key_len, dev);
 599         read_unlock_bh(&tbl->lock);
 600
 601         if (n || !creat)
 602                 goto out;
 603
 604         ASSERT_RTNL();
 605
 606         n = kmalloc(sizeof(*n) + key_len, GFP_KERNEL);
 607         if (!n)
 608                 goto out;
 609
 610         write_pnet(&n->net, hold_net(net));
 611         memcpy(n->key, pkey, key_len);
 612         n->dev = dev;
 613         if (dev)
 614                 dev_hold(dev);
 615
 616         if (tbl->pconstructor && tbl->pconstructor(n)) {
 617                 if (dev)
 618                         dev_put(dev);
 619                 release_net(net);
 620                 kfree(n);
 621                 n = NULL;
 622                 goto out;
 623         }
 624
 625         write_lock_bh(&tbl->lock);
 626         n->next = tbl->phash_buckets[hash_val];
 627         tbl->phash_buckets[hash_val] = n;
 628         write_unlock_bh(&tbl->lock);
 629 out:
 630         return n;
 631 }
 632 EXPORT_SYMBOL(pneigh_lookup);
 633
 634
 635 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *pkey,
 636                   struct net_device *dev)
 637 {
 638         struct pneigh_entry *n, **np;
 639         int key_len = tbl->key_len;
 640         u32 hash_val = pneigh_hash(pkey, key_len);
 641
 642         write_lock_bh(&tbl->lock);
 643         for (np = &tbl->phash_buckets[hash_val]; (n = *np) != NULL;
 644              np = &n->next) {
 645                 if (!memcmp(n->key, pkey, key_len) && n->dev == dev &&
 646                     net_eq(pneigh_net(n), net)) {
 647                         *np = n->next;
 648                         write_unlock_bh(&tbl->lock);
 649                         if (tbl->pdestructor)
 650                                 tbl->pdestructor(n);
 651                         if (n->dev)
 652                                 dev_put(n->dev);
 653                         release_net(pneigh_net(n));
 654                         kfree(n);
 655                         return 0;
 656                 }
 657         }
 658         write_unlock_bh(&tbl->lock);
 659         return -ENOENT;
 660 }
 661
 662 static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 663 {
 664         struct pneigh_entry *n, **np;
 665         u32 h;
 666
 667         for (h = 0; h <= PNEIGH_HASHMASK; h++) {
 668                 np = &tbl->phash_buckets[h];
 669                 while ((n = *np) != NULL) {
 670                         if (!dev || n->dev == dev) {
 671                                 *np = n->next;
 672                                 if (tbl->pdestructor)
 673                                         tbl->pdestructor(n);
 674                                 if (n->dev)
 675                                         dev_put(n->dev);
 676                                 release_net(pneigh_net(n));
 677                                 kfree(n);
 678                                 continue;
 679                         }
 680                         np = &n->next;
 681                 }
 682         }
 683         return -ENOENT;
 684 }
 685
 686 static void neigh_parms_destroy(struct neigh_parms *parms);
 687
 688 static inline void neigh_parms_put(struct neigh_parms *parms)
 689 {
 690         if (atomic_dec_and_test(&parms->refcnt))
 691                 neigh_parms_destroy(parms);
 692 }
 693
 694 /*
 695  *      neighbour must already be out of the table;
 696  *
 697  */
 698 void neigh_destroy(struct neighbour *neigh)
 699 {
 700         struct net_device *dev = neigh->dev;
 701
 702         NEIGH_CACHE_STAT_INC(neigh->tbl, destroys);
 703
 704         if (!neigh->dead) {
 705                 pr_warn("Destroying alive neighbour %p\n", neigh);
 706                 dump_stack();
 707                 return;
 708         }
 709
 710         if (neigh_del_timer(neigh))
 711                 pr_warn("Impossible event\n");
 712
 713         write_lock_bh(&neigh->lock);
 714         __skb_queue_purge(&neigh->arp_queue);
 715         write_unlock_bh(&neigh->lock);
 716         neigh->arp_queue_len_bytes = 0;
 717
 718         if (dev->netdev_ops->ndo_neigh_destroy)
 719                 dev->netdev_ops->ndo_neigh_destroy(neigh);
 720
 721         dev_put(dev);
 722         neigh_parms_put(neigh->parms);
 723
 724         neigh_dbg(2, "neigh %p is destroyed\n", neigh);
 725
 726         atomic_dec(&neigh->tbl->entries);
 727         kfree_rcu(neigh, rcu);
 728 }
 729 EXPORT_SYMBOL(neigh_destroy);
 730
 731 /* Neighbour state is suspicious;
 732    disable fast path.
 733
 734    Called with write_locked neigh.
 735  */
 736 static void neigh_suspect(struct neighbour *neigh)
 737 {
 738         neigh_dbg(2, "neigh %p is suspected\n", neigh);
 739
 740         neigh->output = neigh->ops->output;
 741 }
 742
 743 /* Neighbour state is OK;
 744    enable fast path.
 745
 746    Called with write_locked neigh.
 747  */
 748 static void neigh_connect(struct neighbour *neigh)
 749 {
 750         neigh_dbg(2, "neigh %p is connected\n", neigh);
 751
 752         neigh->output = neigh->ops->connected_output;
 753 }
 754
 755 static void neigh_periodic_work(struct work_struct *work)
 756 {
 757         struct neigh_table *tbl = container_of(work, struct neigh_table, gc_work.work);
 758         struct neighbour *n;
 759         struct neighbour __rcu **np;
 760         unsigned int i;
 761         struct neigh_hash_table *nht;
 762
 763         NEIGH_CACHE_STAT_INC(tbl, periodic_gc_runs);
 764
 765         write_lock_bh(&tbl->lock);
 766         nht = rcu_dereference_protected(tbl->nht,
 767                                         lockdep_is_held(&tbl->lock));
 768
 769         if (atomic_read(&tbl->entries) < tbl->gc_thresh1)
 770                 goto out;
 771
 772         /*
 773          *      periodically recompute ReachableTime from random function
 774          */
 775
 776         if (time_after(jiffies, tbl->last_rand + 300 * HZ)) {
 777                 struct neigh_parms *p;
 778                 tbl->last_rand = jiffies;
 779                 for (p = &tbl->parms; p; p = p->next)
 780                         p->reachable_time =
 781                                 neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
 782         }
 783
 784         for (i = 0 ; i < (1 << nht->hash_shift); i++) {
 785                 np = &nht->hash_buckets[i];
 786
 787                 while ((n = rcu_dereference_protected(*np,
 788                                 lockdep_is_held(&tbl->lock))) != NULL) {
 789                         unsigned int state;
 790
 791                         write_lock(&n->lock);
 792
 793                         state = n->nud_state;
 794                         if (state & (NUD_PERMANENT | NUD_IN_TIMER)) {
 795                                 write_unlock(&n->lock);
 796                                 goto next_elt;
 797                         }
 798
 799                         if (time_before(n->used, n->confirmed))
 800                                 n->used = n->confirmed;
 801
 802                         if (atomic_read(&n->refcnt) == 1 &&
 803                             (state == NUD_FAILED ||
 804                              time_after(jiffies, n->used + NEIGH_VAR(n->parms, GC_STALETIME)))) {
 805                                 *np = n->next;
 806                                 n->dead = 1;
 807                                 write_unlock(&n->lock);
 808                                 neigh_cleanup_and_release(n);
 809                                 continue;
 810                         }
 811                         write_unlock(&n->lock);
 812
 813 next_elt:
 814                         np = &n->next;
 815                 }
 816                 /*
 817                  * It's fine to release lock here, even if hash table
 818                  * grows while we are preempted.
 819                  */
 820                 write_unlock_bh(&tbl->lock);
 821                 cond_resched();
 822                 write_lock_bh(&tbl->lock);
 823                 nht = rcu_dereference_protected(tbl->nht,
 824                                                 lockdep_is_held(&tbl->lock));
 825         }
 826 out:
 827         /* Cycle through all hash buckets every BASE_REACHABLE_TIME/2 ticks.
 828          * ARP entry timeouts range from 1/2 BASE_REACHABLE_TIME to 3/2
 829          * BASE_REACHABLE_TIME.
 830          */
 831         schedule_delayed_work(&tbl->gc_work,
 832                               NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME) >> 1);
 833         write_unlock_bh(&tbl->lock);
 834 }
 835
 836 static __inline__ int neigh_max_probes(struct neighbour *n)
 837 {
 838         struct neigh_parms *p = n->parms;
 839         return (n->nud_state & NUD_PROBE) ?
 840                 NEIGH_VAR(p, UCAST_PROBES) :
 841                 NEIGH_VAR(p, UCAST_PROBES) + NEIGH_VAR(p, APP_PROBES) +
 842                 NEIGH_VAR(p, MCAST_PROBES);
 843 }
 844
 845 static void neigh_invalidate(struct neighbour *neigh)
 846         __releases(neigh->lock)
 847         __acquires(neigh->lock)
 848 {
 849         struct sk_buff *skb;
 850
 851         NEIGH_CACHE_STAT_INC(neigh->tbl, res_failed);
 852         neigh_dbg(2, "neigh %p is failed\n", neigh);
 853         neigh->updated = jiffies;
 854
 855         /* It is very thin place. report_unreachable is very complicated
 856            routine. Particularly, it can hit the same neighbour entry!
 857
 858            So that, we try to be accurate and avoid dead loop. --ANK
 859          */
 860         while (neigh->nud_state == NUD_FAILED &&
 861                (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
 862                 write_unlock(&neigh->lock);
 863                 neigh->ops->error_report(neigh, skb);
 864                 write_lock(&neigh->lock);
 865         }
 866         __skb_queue_purge(&neigh->arp_queue);
 867         neigh->arp_queue_len_bytes = 0;
 868 }
 869
 870 static void neigh_probe(struct neighbour *neigh)
 871         __releases(neigh->lock)
 872 {
 873         struct sk_buff *skb = skb_peek_tail(&neigh->arp_queue);
 874         /* keep skb alive even if arp_queue overflows */
 875         if (skb)
 876                 skb = skb_copy(skb, GFP_ATOMIC);
 877         write_unlock(&neigh->lock);
 878         neigh->ops->solicit(neigh, skb);
 879         atomic_inc(&neigh->probes);
 880         kfree_skb(skb);
 881 }
 882
 883 /* Called when a timer expires for a neighbour entry. */
 884
 885 static void neigh_timer_handler(unsigned long arg)
 886 {
 887         unsigned long now, next;
 888         struct neighbour *neigh = (struct neighbour *)arg;
 889         unsigned int state;
 890         int notify = 0;
 891
 892         write_lock(&neigh->lock);
 893
 894         state = neigh->nud_state;
 895         now = jiffies;
 896         next = now + HZ;
 897
 898         if (!(state & NUD_IN_TIMER))
 899                 goto out;
 900
 901         if (state & NUD_REACHABLE) {
 902                 if (time_before_eq(now,
 903                                    neigh->confirmed + neigh->parms->reachable_time)) {
 904                         neigh_dbg(2, "neigh %p is still alive\n", neigh);
 905                         next = neigh->confirmed + neigh->parms->reachable_time;
 906                 } else if (time_before_eq(now,
 907                                           neigh->used +
 908                                           NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME))) {
 909                         neigh_dbg(2, "neigh %p is delayed\n", neigh);
 910                         neigh->nud_state = NUD_DELAY;
 911                         neigh->updated = jiffies;
 912                         neigh_suspect(neigh);
 913                         next = now + NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME);
 914                 } else {
 915                         neigh_dbg(2, "neigh %p is suspected\n", neigh);
 916                         neigh->nud_state = NUD_STALE;
 917                         neigh->updated = jiffies;
 918                         neigh_suspect(neigh);
 919                         notify = 1;
 920                 }
 921         } else if (state & NUD_DELAY) {
 922                 if (time_before_eq(now,
 923                                    neigh->confirmed +
 924                                    NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME))) {
 925                         neigh_dbg(2, "neigh %p is now reachable\n", neigh);
 926                         neigh->nud_state = NUD_REACHABLE;
 927                         neigh->updated = jiffies;
 928                         neigh_connect(neigh);
 929                         notify = 1;
 930                         next = neigh->confirmed + neigh->parms->reachable_time;
 931                 } else {
 932                         neigh_dbg(2, "neigh %p is probed\n", neigh);
 933                         neigh->nud_state = NUD_PROBE;
 934                         neigh->updated = jiffies;
 935                         atomic_set(&neigh->probes, 0);
 936                         next = now + NEIGH_VAR(neigh->parms, RETRANS_TIME);
 937                 }
 938         } else {
 939                 /* NUD_PROBE|NUD_INCOMPLETE */
 940                 next = now + NEIGH_VAR(neigh->parms, RETRANS_TIME);
 941         }
 942
 943         if ((neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) &&
 944             atomic_read(&neigh->probes) >= neigh_max_probes(neigh)) {
 945                 neigh->nud_state = NUD_FAILED;
 946                 notify = 1;
 947                 neigh_invalidate(neigh);
 948         }
 949
 950         if (neigh->nud_state & NUD_IN_TIMER) {
 951                 if (time_before(next, jiffies + HZ/2))
 952                         next = jiffies + HZ/2;
 953                 if (!mod_timer(&neigh->timer, next))
 954                         neigh_hold(neigh);
 955         }
 956         if (neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) {
 957                 neigh_probe(neigh);
 958         } else {
 959 out:
 960                 write_unlock(&neigh->lock);
 961         }
 962
 963         if (notify)
 964                 neigh_update_notify(neigh);
 965
 966         neigh_release(neigh);
 967 }
 968
 969 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 970 {
 971         int rc;
 972         bool immediate_probe = false;
 973
 974         write_lock_bh(&neigh->lock);
 975
 976         rc = 0;
 977         if (neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE))
 978                 goto out_unlock_bh;
 979
 980         if (!(neigh->nud_state & (NUD_STALE | NUD_INCOMPLETE))) {
 981                 if (NEIGH_VAR(neigh->parms, MCAST_PROBES) +
 982                     NEIGH_VAR(neigh->parms, APP_PROBES)) {
 983                         unsigned long next, now = jiffies;
 984
 985                         atomic_set(&neigh->probes,
 986                                    NEIGH_VAR(neigh->parms, UCAST_PROBES));
 987                         neigh->nud_state     = NUD_INCOMPLETE;
 988                         neigh->updated = now;
 989                         next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),
 990                                          HZ/2);
 991                         neigh_add_timer(neigh, next);
 992                         immediate_probe = true;
 993                 } else {
 994                         neigh->nud_state = NUD_FAILED;
 995                         neigh->updated = jiffies;
 996                         write_unlock_bh(&neigh->lock);
 997
 998                         kfree_skb(skb);
 999                         return 1;
1000                 }
1001         } else if (neigh->nud_state & NUD_STALE) {
1002                 neigh_dbg(2, "neigh %p is delayed\n", neigh);
1003                 neigh->nud_state = NUD_DELAY;
1004                 neigh->updated = jiffies;
1005                 neigh_add_timer(neigh, jiffies +
1006                                 NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME));
1007         }
1008
1009         if (neigh->nud_state == NUD_INCOMPLETE) {
1010                 if (skb) {
1011                         while (neigh->arp_queue_len_bytes + skb->truesize >
1012                                NEIGH_VAR(neigh->parms, QUEUE_LEN_BYTES)) {
1013                                 struct sk_buff *buff;
1014
1015                                 buff = __skb_dequeue(&neigh->arp_queue);
1016                                 if (!buff)
1017                                         break;
1018                                 neigh->arp_queue_len_bytes -= buff->truesize;
1019                                 kfree_skb(buff);
1020                                 NEIGH_CACHE_STAT_INC(neigh->tbl, unres_discards);
1021                         }
1022                         skb_dst_force(skb);
1023                         __skb_queue_tail(&neigh->arp_queue, skb);
1024                         neigh->arp_queue_len_bytes += skb->truesize;
1025                 }
1026                 rc = 1;
1027         }
1028 out_unlock_bh:
1029         if (immediate_probe)
1030                 neigh_probe(neigh);
1031         else
1032                 write_unlock(&neigh->lock);
1033         local_bh_enable();
1034         return rc;
1035 }
1036 EXPORT_SYMBOL(__neigh_event_send);
1037
1038 static void neigh_update_hhs(struct neighbour *neigh)
1039 {
1040         struct hh_cache *hh;
1041         void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *)
1042                 = NULL;
1043
1044         if (neigh->dev->header_ops)
1045                 update = neigh->dev->header_ops->cache_update;
1046
1047         if (update) {
1048                 hh = &neigh->hh;
1049                 if (hh->hh_len) {
1050                         write_seqlock_bh(&hh->hh_lock);
1051                         update(hh, neigh->dev, neigh->ha);
1052                         write_sequnlock_bh(&hh->hh_lock);
1053                 }
1054         }
1055 }
1056
1057
1058
1059 /* Generic update routine.
1060    -- lladdr is new lladdr or NULL, if it is not supplied.
1061    -- new    is new state.
1062    -- flags
1063         NEIGH_UPDATE_F_OVERRIDE allows to override existing lladdr,
1064                                 if it is different.
1065         NEIGH_UPDATE_F_WEAK_OVERRIDE will suspect existing "connected"
1066                                 lladdr instead of overriding it
1067                                 if it is different.
1068                                 It also allows to retain current state
1069                                 if lladdr is unchanged.
1070         NEIGH_UPDATE_F_ADMIN    means that the change is administrative.
1071
1072         NEIGH_UPDATE_F_OVERRIDE_ISROUTER allows to override existing
1073                                 NTF_ROUTER flag.
1074         NEIGH_UPDATE_F_ISROUTER indicates if the neighbour is known as
1075                                 a router.
1076
1077    Caller MUST hold reference count on the entry.
1078  */
1079
1080 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
1081                  u32 flags)
1082 {
1083         u8 old;
1084         int err;
1085         int notify = 0;
1086         struct net_device *dev;
1087         int update_isrouter = 0;
1088
1089         write_lock_bh(&neigh->lock);
1090
1091         dev    = neigh->dev;
1092         old    = neigh->nud_state;
1093         err    = -EPERM;
1094
1095         if (!(flags & NEIGH_UPDATE_F_ADMIN) &&
1096             (old & (NUD_NOARP | NUD_PERMANENT)))
1097                 goto out;
1098
1099         if (!(new & NUD_VALID)) {
1100                 neigh_del_timer(neigh);
1101                 if (old & NUD_CONNECTED)
1102                         neigh_suspect(neigh);
1103                 neigh->nud_state = new;
1104                 err = 0;
1105                 notify = old & NUD_VALID;
1106                 if ((old & (NUD_INCOMPLETE | NUD_PROBE)) &&
1107                     (new & NUD_FAILED)) {
1108                         neigh_invalidate(neigh);
1109                         notify = 1;
1110                 }
1111                 goto out;
1112         }
1113
1114         /* Compare new lladdr with cached one */
1115         if (!dev->addr_len) {
1116                 /* First case: device needs no address. */
1117                 lladdr = neigh->ha;
1118         } else if (lladdr) {
1119                 /* The second case: if something is already cached
1120                    and a new address is proposed:
1121                    - compare new & old
1122                    - if they are different, check override flag
1123                  */
1124                 if ((old & NUD_VALID) &&
1125                     !memcmp(lladdr, neigh->ha, dev->addr_len))
1126                         lladdr = neigh->ha;
1127         } else {
1128                 /* No address is supplied; if we know something,
1129                    use it, otherwise discard the request.
1130                  */
1131                 err = -EINVAL;
1132                 if (!(old & NUD_VALID))
1133                         goto out;
1134                 lladdr = neigh->ha;
1135         }
1136
1137         if (new & NUD_CONNECTED)
1138                 neigh->confirmed = jiffies;
1139         neigh->updated = jiffies;
1140
1141         /* If entry was valid and address is not changed,
1142            do not change entry state, if new one is STALE.
1143          */
1144         err = 0;
1145         update_isrouter = flags & NEIGH_UPDATE_F_OVERRIDE_ISROUTER;
1146         if (old & NUD_VALID) {
1147                 if (lladdr != neigh->ha && !(flags & NEIGH_UPDATE_F_OVERRIDE)) {
1148                         update_isrouter = 0;
1149                         if ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) &&
1150                             (old & NUD_CONNECTED)) {
1151                                 lladdr = neigh->ha;
1152                                 new = NUD_STALE;
1153                         } else
1154                                 goto out;
1155                 } else {
1156                         if (lladdr == neigh->ha && new == NUD_STALE &&
1157                             ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) ||
1158                              (old & NUD_CONNECTED))
1159                             )
1160                                 new = old;
1161                 }
1162         }
1163
1164         if (new != old) {
1165                 neigh_del_timer(neigh);
1166                 if (new & NUD_IN_TIMER)
1167                         neigh_add_timer(neigh, (jiffies +
1168                                                 ((new & NUD_REACHABLE) ?
1169                                                  neigh->parms->reachable_time :
1170                                                  0)));
1171                 neigh->nud_state = new;
1172                 notify = 1;
1173         }
1174
1175         if (lladdr != neigh->ha) {
1176                 write_seqlock(&neigh->ha_lock);
1177                 memcpy(&neigh->ha, lladdr, dev->addr_len);
1178                 write_sequnlock(&neigh->ha_lock);
1179                 neigh_update_hhs(neigh);
1180                 if (!(new & NUD_CONNECTED))
1181                         neigh->confirmed = jiffies -
1182                                       (NEIGH_VAR(neigh->parms, BASE_REACHABLE_TIME) << 1);
1183                 notify = 1;
1184         }
1185         if (new == old)
1186                 goto out;
1187         if (new & NUD_CONNECTED)
1188                 neigh_connect(neigh);
1189         else
1190                 neigh_suspect(neigh);
1191         if (!(old & NUD_VALID)) {
1192                 struct sk_buff *skb;
1193
1194                 /* Again: avoid dead loop if something went wrong */
1195
1196                 while (neigh->nud_state & NUD_VALID &&
1197                        (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
1198                         struct dst_entry *dst = skb_dst(skb);
1199                         struct neighbour *n2, *n1 = neigh;
1200                         write_unlock_bh(&neigh->lock);
1201
1202                         rcu_read_lock();
1203
1204                         /* Why not just use 'neigh' as-is?  The problem is that
1205                          * things such as shaper, eql, and sch_teql can end up
1206                          * using alternative, different, neigh objects to output
1207                          * the packet in the output path.  So what we need to do
1208                          * here is re-lookup the top-level neigh in the path so
1209                          * we can reinject the packet there.
1210                          */
1211                         n2 = NULL;
1212                         if (dst) {
1213                                 n2 = dst_neigh_lookup_skb(dst, skb);
1214                                 if (n2)
1215                                         n1 = n2;
1216                         }
1217                         n1->output(n1, skb);
1218                         if (n2)
1219                                 neigh_release(n2);
1220                         rcu_read_unlock();
1221
1222                         write_lock_bh(&neigh->lock);
1223                 }
1224                 __skb_queue_purge(&neigh->arp_queue);
1225                 neigh->arp_queue_len_bytes = 0;
1226         }
1227 out:
1228         if (update_isrouter) {
1229                 neigh->flags = (flags & NEIGH_UPDATE_F_ISROUTER) ?
1230                         (neigh->flags | NTF_ROUTER) :
1231                         (neigh->flags & ~NTF_ROUTER);
1232         }
1233         write_unlock_bh(&neigh->lock);
1234
1235         if (notify)
1236                 neigh_update_notify(neigh);
1237
1238         return err;
1239 }
1240 EXPORT_SYMBOL(neigh_update);
1241
1242 /* Update the neigh to listen temporarily for probe responses, even if it is
1243  * in a NUD_FAILED state. The caller has to hold neigh->lock for writing.
1244  */
1245 void __neigh_set_probe_once(struct neighbour *neigh)
1246 {
1247         neigh->updated = jiffies;
1248         if (!(neigh->nud_state & NUD_FAILED))
1249                 return;
1250         neigh->nud_state = NUD_PROBE;
1251         atomic_set(&neigh->probes, NEIGH_VAR(neigh->parms, UCAST_PROBES));
1252         neigh_add_timer(neigh,
1253                         jiffies + NEIGH_VAR(neigh->parms, RETRANS_TIME));
1254 }
1255 EXPORT_SYMBOL(__neigh_set_probe_once);
1256
1257 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
1258                                  u8 *lladdr, void *saddr,
1259                                  struct net_device *dev)
1260 {
1261         struct neighbour *neigh = __neigh_lookup(tbl, saddr, dev,
1262                                                  lladdr || !dev->addr_len);
1263         if (neigh)
1264                 neigh_update(neigh, lladdr, NUD_STALE,
1265                              NEIGH_UPDATE_F_OVERRIDE);
1266         return neigh;
1267 }
1268 EXPORT_SYMBOL(neigh_event_ns);
1269
1270 /* called with read_lock_bh(&n->lock); */
1271 static void neigh_hh_init(struct neighbour *n, struct dst_entry *dst)
1272 {
1273         struct net_device *dev = dst->dev;
1274         __be16 prot = dst->ops->protocol;
1275         struct hh_cache *hh = &n->hh;
1276
1277         write_lock_bh(&n->lock);
1278
1279         /* Only one thread can come in here and initialize the
1280          * hh_cache entry.
1281          */
1282         if (!hh->hh_len)
1283                 dev->header_ops->cache(n, hh, prot);
1284
1285         write_unlock_bh(&n->lock);
1286 }
1287
1288 /* This function can be used in contexts, where only old dev_queue_xmit
1289  * worked, f.e. if you want to override normal output path (eql, shaper),
1290  * but resolution is not made yet.
1291  */
1292
1293 int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb)
1294 {
1295         struct net_device *dev = skb->dev;
1296
1297         __skb_pull(skb, skb_network_offset(skb));
1298
1299         if (dev_hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
1300                             skb->len) < 0 &&
1301             dev->header_ops->rebuild(skb))
1302                 return 0;
1303
1304         return dev_queue_xmit(skb);
1305 }
1306 EXPORT_SYMBOL(neigh_compat_output);
1307
1308 /* Slow and careful. */
1309
1310 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb)
1311 {
1312         struct dst_entry *dst = skb_dst(skb);
1313         int rc = 0;
1314
1315         if (!dst)
1316                 goto discard;
1317
1318         if (!neigh_event_send(neigh, skb)) {
1319                 int err;
1320                 struct net_device *dev = neigh->dev;
1321                 unsigned int seq;
1322
1323                 if (dev->header_ops->cache && !neigh->hh.hh_len)
1324                         neigh_hh_init(neigh, dst);
1325
1326                 do {
1327                         __skb_pull(skb, skb_network_offset(skb));
1328                         seq = read_seqbegin(&neigh->ha_lock);
1329                         err = dev_hard_header(skb, dev, ntohs(skb->protocol),
1330                                               neigh->ha, NULL, skb->len);
1331                 } while (read_seqretry(&neigh->ha_lock, seq));
1332
1333                 if (err >= 0)
1334                         rc = dev_queue_xmit(skb);
1335                 else
1336                         goto out_kfree_skb;
1337         }
1338 out:
1339         return rc;
1340 discard:
1341         neigh_dbg(1, "%s: dst=%p neigh=%p\n", __func__, dst, neigh);
1342 out_kfree_skb:
1343         rc = -EINVAL;
1344         kfree_skb(skb);
1345         goto out;
1346 }
1347 EXPORT_SYMBOL(neigh_resolve_output);
1348
1349 /* As fast as possible without hh cache */
1350
1351 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb)
1352 {
1353         struct net_device *dev = neigh->dev;
1354         unsigned int seq;
1355         int err;
1356
1357         do {
1358                 __skb_pull(skb, skb_network_offset(skb));
1359                 seq = read_seqbegin(&neigh->ha_lock);
1360                 err = dev_hard_header(skb, dev, ntohs(skb->protocol),
1361                                       neigh->ha, NULL, skb->len);
1362         } while (read_seqretry(&neigh->ha_lock, seq));
1363
1364         if (err >= 0)
1365                 err = dev_queue_xmit(skb);
1366         else {
1367                 err = -EINVAL;
1368                 kfree_skb(skb);
1369         }
1370         return err;
1371 }
1372 EXPORT_SYMBOL(neigh_connected_output);
1373
1374 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb)
1375 {
1376         return dev_queue_xmit(skb);
1377 }
1378 EXPORT_SYMBOL(neigh_direct_output);
1379
1380 static void neigh_proxy_process(unsigned long arg)
1381 {
1382         struct neigh_table *tbl = (struct neigh_table *)arg;
1383         long sched_next = 0;
1384         unsigned long now = jiffies;
1385         struct sk_buff *skb, *n;
1386
1387         spin_lock(&tbl->proxy_queue.lock);
1388
1389         skb_queue_walk_safe(&tbl->proxy_queue, skb, n) {
1390                 long tdif = NEIGH_CB(skb)->sched_next - now;
1391
1392                 if (tdif <= 0) {
1393                         struct net_device *dev = skb->dev;
1394
1395                         __skb_unlink(skb, &tbl->proxy_queue);
1396                         if (tbl->proxy_redo && netif_running(dev)) {
1397                                 rcu_read_lock();
1398                                 tbl->proxy_redo(skb);
1399                                 rcu_read_unlock();
1400                         } else {
1401                                 kfree_skb(skb);
1402                         }
1403
1404                         dev_put(dev);
1405                 } else if (!sched_next || tdif < sched_next)
1406                         sched_next = tdif;
1407         }
1408         del_timer(&tbl->proxy_timer);
1409         if (sched_next)
1410                 mod_timer(&tbl->proxy_timer, jiffies + sched_next);
1411         spin_unlock(&tbl->proxy_queue.lock);
1412 }
1413
1414 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
1415                     struct sk_buff *skb)
1416 {
1417         unsigned long now = jiffies;
1418         unsigned long sched_next = now + (net_random() %
1419                                           NEIGH_VAR(p, PROXY_DELAY));
1420
1421         if (tbl->proxy_queue.qlen > NEIGH_VAR(p, PROXY_QLEN)) {
1422                 kfree_skb(skb);
1423                 return;
1424         }
1425
1426         NEIGH_CB(skb)->sched_next = sched_next;
1427         NEIGH_CB(skb)->flags |= LOCALLY_ENQUEUED;
1428
1429         spin_lock(&tbl->proxy_queue.lock);
1430         if (del_timer(&tbl->proxy_timer)) {
1431                 if (time_before(tbl->proxy_timer.expires, sched_next))
1432                         sched_next = tbl->proxy_timer.expires;
1433         }
1434         skb_dst_drop(skb);
1435         dev_hold(skb->dev);
1436         __skb_queue_tail(&tbl->proxy_queue, skb);
1437         mod_timer(&tbl->proxy_timer, sched_next);
1438         spin_unlock(&tbl->proxy_queue.lock);
1439 }
1440 EXPORT_SYMBOL(pneigh_enqueue);
1441
1442 static inline struct neigh_parms *lookup_neigh_parms(struct neigh_table *tbl,
1443                                                       struct net *net, int ifindex)
1444 {
1445         struct neigh_parms *p;
1446
1447         for (p = &tbl->parms; p; p = p->next) {
1448                 if ((p->dev && p->dev->ifindex == ifindex && net_eq(neigh_parms_net(p), net)) ||
1449                     (!p->dev && !ifindex && net_eq(net, &init_net)))
1450                         return p;
1451         }
1452
1453         return NULL;
1454 }
1455
1456 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
1457                                       struct neigh_table *tbl)
1458 {
1459         struct neigh_parms *p;
1460         struct net *net = dev_net(dev);
1461         const struct net_device_ops *ops = dev->netdev_ops;
1462
1463         p = kmemdup(&tbl->parms, sizeof(*p), GFP_KERNEL);
1464         if (p) {
1465                 p->tbl            = tbl;
1466                 atomic_set(&p->refcnt, 1);
1467                 p->reachable_time =
1468                                 neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
1469                 dev_hold(dev);
1470                 p->dev = dev;
1471                 write_pnet(&p->net, hold_net(net));
1472                 p->sysctl_table = NULL;
1473
1474                 if (ops->ndo_neigh_setup && ops->ndo_neigh_setup(dev, p)) {
1475                         release_net(net);
1476                         dev_put(dev);
1477                         kfree(p);
1478                         return NULL;
1479                 }
1480
1481                 write_lock_bh(&tbl->lock);
1482                 p->next         = tbl->parms.next;
1483                 tbl->parms.next = p;
1484                 write_unlock_bh(&tbl->lock);
1485
1486                 neigh_parms_data_state_cleanall(p);
1487         }
1488         return p;
1489 }
1490 EXPORT_SYMBOL(neigh_parms_alloc);
1491
1492 static void neigh_rcu_free_parms(struct rcu_head *head)
1493 {
1494         struct neigh_parms *parms =
1495                 container_of(head, struct neigh_parms, rcu_head);
1496
1497         neigh_parms_put(parms);
1498 }
1499
1500 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
1501 {
1502         struct neigh_parms **p;
1503
1504         if (!parms || parms == &tbl->parms)
1505                 return;
1506         write_lock_bh(&tbl->lock);
1507         for (p = &tbl->parms.next; *p; p = &(*p)->next) {
1508                 if (*p == parms) {
1509                         *p = parms->next;
1510                         parms->dead = 1;
1511                         write_unlock_bh(&tbl->lock);
1512                         if (parms->dev)
1513                                 dev_put(parms->dev);
1514                         call_rcu(&parms->rcu_head, neigh_rcu_free_parms);
1515                         return;
1516                 }
1517         }
1518         write_unlock_bh(&tbl->lock);
1519         neigh_dbg(1, "%s: not found\n", __func__);
1520 }
1521 EXPORT_SYMBOL(neigh_parms_release);
1522
1523 static void neigh_parms_destroy(struct neigh_parms *parms)
1524 {
1525         release_net(neigh_parms_net(parms));
1526         kfree(parms);
1527 }
1528
1529 static struct lock_class_key neigh_table_proxy_queue_class;
1530
1531 static void neigh_table_init_no_netlink(struct neigh_table *tbl)
1532 {
1533         unsigned long now = jiffies;
1534         unsigned long phsize;
1535
1536         write_pnet(&tbl->parms.net, &init_net);
1537         atomic_set(&tbl->parms.refcnt, 1);
1538         tbl->parms.reachable_time =
1539                           neigh_rand_reach_time(NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME));
1540
1541         tbl->stats = alloc_percpu(struct neigh_statistics);
1542         if (!tbl->stats)
1543                 panic("cannot create neighbour cache statistics");
1544
1545 #ifdef CONFIG_PROC_FS
1546         if (!proc_create_data(tbl->id, 0, init_net.proc_net_stat,
1547                               &neigh_stat_seq_fops, tbl))
1548                 panic("cannot create neighbour proc dir entry");
1549 #endif
1550
1551         RCU_INIT_POINTER(tbl->nht, neigh_hash_alloc(3));
1552
1553         phsize = (PNEIGH_HASHMASK + 1) * sizeof(struct pneigh_entry *);
1554         tbl->phash_buckets = kzalloc(phsize, GFP_KERNEL);
1555
1556         if (!tbl->nht || !tbl->phash_buckets)
1557                 panic("cannot allocate neighbour cache hashes");
1558
1559         if (!tbl->entry_size)
1560                 tbl->entry_size = ALIGN(offsetof(struct neighbour, primary_key) +
1561                                         tbl->key_len, NEIGH_PRIV_ALIGN);
1562         else
1563                 WARN_ON(tbl->entry_size % NEIGH_PRIV_ALIGN);
1564
1565         rwlock_init(&tbl->lock);
1566         INIT_DEFERRABLE_WORK(&tbl->gc_work, neigh_periodic_work);
1567         schedule_delayed_work(&tbl->gc_work, tbl->parms.reachable_time);
1568         setup_timer(&tbl->proxy_timer, neigh_proxy_process, (unsigned long)tbl);
1569         skb_queue_head_init_class(&tbl->proxy_queue,
1570                         &neigh_table_proxy_queue_class);
1571
1572         tbl->last_flush = now;
1573         tbl->last_rand  = now + tbl->parms.reachable_time * 20;
1574 }
1575
1576 void neigh_table_init(struct neigh_table *tbl)
1577 {
1578         struct neigh_table *tmp;
1579
1580         neigh_table_init_no_netlink(tbl);
1581         write_lock(&neigh_tbl_lock);
1582         for (tmp = neigh_tables; tmp; tmp = tmp->next) {
1583                 if (tmp->family == tbl->family)
1584                         break;
1585         }
1586         tbl->next       = neigh_tables;
1587         neigh_tables    = tbl;
1588         write_unlock(&neigh_tbl_lock);
1589
1590         if (unlikely(tmp)) {
1591                 pr_err("Registering multiple tables for family %d\n",
1592                        tbl->family);
1593                 dump_stack();
1594         }
1595 }
1596 EXPORT_SYMBOL(neigh_table_init);
1597
1598 int neigh_table_clear(struct neigh_table *tbl)
1599 {
1600         struct neigh_table **tp;
1601
1602         /* It is not clean... Fix it to unload IPv6 module safely */
1603         cancel_delayed_work_sync(&tbl->gc_work);
1604         del_timer_sync(&tbl->proxy_timer);
1605         pneigh_queue_purge(&tbl->proxy_queue);
1606         neigh_ifdown(tbl, NULL);
1607         if (atomic_read(&tbl->entries))
1608                 pr_crit("neighbour leakage\n");
1609         write_lock(&neigh_tbl_lock);
1610         for (tp = &neigh_tables; *tp; tp = &(*tp)->next) {
1611                 if (*tp == tbl) {
1612                         *tp = tbl->next;
1613                         break;
1614                 }
1615         }
1616         write_unlock(&neigh_tbl_lock);
1617
1618         call_rcu(&rcu_dereference_protected(tbl->nht, 1)->rcu,
1619                  neigh_hash_free_rcu);
1620         tbl->nht = NULL;
1621
1622         kfree(tbl->phash_buckets);
1623         tbl->phash_buckets = NULL;
1624
1625         remove_proc_entry(tbl->id, init_net.proc_net_stat);
1626
1627         free_percpu(tbl->stats);
1628         tbl->stats = NULL;
1629
1630         return 0;
1631 }
1632 EXPORT_SYMBOL(neigh_table_clear);
1633
1634 static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh)
1635 {
1636         struct net *net = sock_net(skb->sk);
1637         struct ndmsg *ndm;
1638         struct nlattr *dst_attr;
1639         struct neigh_table *tbl;
1640         struct net_device *dev = NULL;
1641         int err = -EINVAL;
1642
1643         ASSERT_RTNL();
1644         if (nlmsg_len(nlh) < sizeof(*ndm))
1645                 goto out;
1646
1647         dst_attr = nlmsg_find_attr(nlh, sizeof(*ndm), NDA_DST);
1648         if (dst_attr == NULL)
1649                 goto out;
1650
1651         ndm = nlmsg_data(nlh);
1652         if (ndm->ndm_ifindex) {
1653                 dev = __dev_get_by_index(net, ndm->ndm_ifindex);
1654                 if (dev == NULL) {
1655                         err = -ENODEV;
1656                         goto out;
1657                 }
1658         }
1659
1660         read_lock(&neigh_tbl_lock);
1661         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1662                 struct neighbour *neigh;
1663
1664                 if (tbl->family != ndm->ndm_family)
1665                         continue;
1666                 read_unlock(&neigh_tbl_lock);
1667
1668                 if (nla_len(dst_attr) < tbl->key_len)
1669                         goto out;
1670
1671                 if (ndm->ndm_flags & NTF_PROXY) {
1672                         err = pneigh_delete(tbl, net, nla_data(dst_attr), dev);
1673                         goto out;
1674                 }
1675
1676                 if (dev == NULL)
1677                         goto out;
1678
1679                 neigh = neigh_lookup(tbl, nla_data(dst_attr), dev);
1680                 if (neigh == NULL) {
1681                         err = -ENOENT;
1682                         goto out;
1683                 }
1684
1685                 err = neigh_update(neigh, NULL, NUD_FAILED,
1686                                    NEIGH_UPDATE_F_OVERRIDE |
1687                                    NEIGH_UPDATE_F_ADMIN);
1688                 neigh_release(neigh);
1689                 goto out;
1690         }
1691         read_unlock(&neigh_tbl_lock);
1692         err = -EAFNOSUPPORT;
1693
1694 out:
1695         return err;
1696 }
1697
1698 static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh)
1699 {
1700         struct net *net = sock_net(skb->sk);
1701         struct ndmsg *ndm;
1702         struct nlattr *tb[NDA_MAX+1];
1703         struct neigh_table *tbl;
1704         struct net_device *dev = NULL;
1705         int err;
1706
1707         ASSERT_RTNL();
1708         err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
1709         if (err < 0)
1710                 goto out;
1711
1712         err = -EINVAL;
1713         if (tb[NDA_DST] == NULL)
1714                 goto out;
1715
1716         ndm = nlmsg_data(nlh);
1717         if (ndm->ndm_ifindex) {
1718                 dev = __dev_get_by_index(net, ndm->ndm_ifindex);
1719                 if (dev == NULL) {
1720                         err = -ENODEV;
1721                         goto out;
1722                 }
1723
1724                 if (tb[NDA_LLADDR] && nla_len(tb[NDA_LLADDR]) < dev->addr_len)
1725                         goto out;
1726         }
1727
1728         read_lock(&neigh_tbl_lock);
1729         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1730                 int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE;
1731                 struct neighbour *neigh;
1732                 void *dst, *lladdr;
1733
1734                 if (tbl->family != ndm->ndm_family)
1735                         continue;
1736                 read_unlock(&neigh_tbl_lock);
1737
1738                 if (nla_len(tb[NDA_DST]) < tbl->key_len)
1739                         goto out;
1740                 dst = nla_data(tb[NDA_DST]);
1741                 lladdr = tb[NDA_LLADDR] ? nla_data(tb[NDA_LLADDR]) : NULL;
1742
1743                 if (ndm->ndm_flags & NTF_PROXY) {
1744                         struct pneigh_entry *pn;
1745
1746                         err = -ENOBUFS;
1747                         pn = pneigh_lookup(tbl, net, dst, dev, 1);
1748                         if (pn) {
1749                                 pn->flags = ndm->ndm_flags;
1750                                 err = 0;
1751                         }
1752                         goto out;
1753                 }
1754
1755                 if (dev == NULL)
1756                         goto out;
1757
1758                 neigh = neigh_lookup(tbl, dst, dev);
1759                 if (neigh == NULL) {
1760                         if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
1761                                 err = -ENOENT;
1762                                 goto out;
1763                         }
1764
1765                         neigh = __neigh_lookup_errno(tbl, dst, dev);
1766                         if (IS_ERR(neigh)) {
1767                                 err = PTR_ERR(neigh);
1768                                 goto out;
1769                         }
1770                 } else {
1771                         if (nlh->nlmsg_flags & NLM_F_EXCL) {
1772                                 err = -EEXIST;
1773                                 neigh_release(neigh);
1774                                 goto out;
1775                         }
1776
1777                         if (!(nlh->nlmsg_flags & NLM_F_REPLACE))
1778                                 flags &= ~NEIGH_UPDATE_F_OVERRIDE;
1779                 }
1780
1781                 if (ndm->ndm_flags & NTF_USE) {
1782                         neigh_event_send(neigh, NULL);
1783                         err = 0;
1784                 } else
1785                         err = neigh_update(neigh, lladdr, ndm->ndm_state, flags);
1786                 neigh_release(neigh);
1787                 goto out;
1788         }
1789
1790         read_unlock(&neigh_tbl_lock);
1791         err = -EAFNOSUPPORT;
1792 out:
1793         return err;
1794 }
1795
1796 static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms)
1797 {
1798         struct nlattr *nest;
1799
1800         nest = nla_nest_start(skb, NDTA_PARMS);
1801         if (nest == NULL)
1802                 return -ENOBUFS;
1803
1804         if ((parms->dev &&
1805              nla_put_u32(skb, NDTPA_IFINDEX, parms->dev->ifindex)) ||
1806             nla_put_u32(skb, NDTPA_REFCNT, atomic_read(&parms->refcnt)) ||
1807             nla_put_u32(skb, NDTPA_QUEUE_LENBYTES,
1808                         NEIGH_VAR(parms, QUEUE_LEN_BYTES)) ||
1809             /* approximative value for deprecated QUEUE_LEN (in packets) */
1810             nla_put_u32(skb, NDTPA_QUEUE_LEN,
1811                         NEIGH_VAR(parms, QUEUE_LEN_BYTES) / SKB_TRUESIZE(ETH_FRAME_LEN)) ||
1812             nla_put_u32(skb, NDTPA_PROXY_QLEN, NEIGH_VAR(parms, PROXY_QLEN)) ||
1813             nla_put_u32(skb, NDTPA_APP_PROBES, NEIGH_VAR(parms, APP_PROBES)) ||
1814             nla_put_u32(skb, NDTPA_UCAST_PROBES,
1815                         NEIGH_VAR(parms, UCAST_PROBES)) ||
1816             nla_put_u32(skb, NDTPA_MCAST_PROBES,
1817                         NEIGH_VAR(parms, MCAST_PROBES)) ||
1818             nla_put_msecs(skb, NDTPA_REACHABLE_TIME, parms->reachable_time) ||
1819             nla_put_msecs(skb, NDTPA_BASE_REACHABLE_TIME,
1820                           NEIGH_VAR(parms, BASE_REACHABLE_TIME)) ||
1821             nla_put_msecs(skb, NDTPA_GC_STALETIME,
1822                           NEIGH_VAR(parms, GC_STALETIME)) ||
1823             nla_put_msecs(skb, NDTPA_DELAY_PROBE_TIME,
1824                           NEIGH_VAR(parms, DELAY_PROBE_TIME)) ||
1825             nla_put_msecs(skb, NDTPA_RETRANS_TIME,
1826                           NEIGH_VAR(parms, RETRANS_TIME)) ||
1827             nla_put_msecs(skb, NDTPA_ANYCAST_DELAY,
1828                           NEIGH_VAR(parms, ANYCAST_DELAY)) ||
1829             nla_put_msecs(skb, NDTPA_PROXY_DELAY,
1830                           NEIGH_VAR(parms, PROXY_DELAY)) ||
1831             nla_put_msecs(skb, NDTPA_LOCKTIME,
1832                           NEIGH_VAR(parms, LOCKTIME)))
1833                 goto nla_put_failure;
1834         return nla_nest_end(skb, nest);
1835
1836 nla_put_failure:
1837         nla_nest_cancel(skb, nest);
1838         return -EMSGSIZE;
1839 }
1840
1841 static int neightbl_fill_info(struct sk_buff *skb, struct neigh_table *tbl,
1842                               u32 pid, u32 seq, int type, int flags)
1843 {
1844         struct nlmsghdr *nlh;
1845         struct ndtmsg *ndtmsg;
1846
1847         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
1848         if (nlh == NULL)
1849                 return -EMSGSIZE;
1850
1851         ndtmsg = nlmsg_data(nlh);
1852
1853         read_lock_bh(&tbl->lock);
1854         ndtmsg->ndtm_family = tbl->family;
1855         ndtmsg->ndtm_pad1   = 0;
1856         ndtmsg->ndtm_pad2   = 0;
1857
1858         if (nla_put_string(skb, NDTA_NAME, tbl->id) ||
1859             nla_put_msecs(skb, NDTA_GC_INTERVAL, tbl->gc_interval) ||
1860             nla_put_u32(skb, NDTA_THRESH1, tbl->gc_thresh1) ||
1861             nla_put_u32(skb, NDTA_THRESH2, tbl->gc_thresh2) ||
1862             nla_put_u32(skb, NDTA_THRESH3, tbl->gc_thresh3))
1863                 goto nla_put_failure;
1864         {
1865                 unsigned long now = jiffies;
1866                 unsigned int flush_delta = now - tbl->last_flush;
1867                 unsigned int rand_delta = now - tbl->last_rand;
1868                 struct neigh_hash_table *nht;
1869                 struct ndt_config ndc = {
1870                         .ndtc_key_len           = tbl->key_len,
1871                         .ndtc_entry_size        = tbl->entry_size,
1872                         .ndtc_entries           = atomic_read(&tbl->entries),
1873                         .ndtc_last_flush        = jiffies_to_msecs(flush_delta),
1874                         .ndtc_last_rand         = jiffies_to_msecs(rand_delta),
1875                         .ndtc_proxy_qlen        = tbl->proxy_queue.qlen,
1876                 };
1877
1878                 rcu_read_lock_bh();
1879                 nht = rcu_dereference_bh(tbl->nht);
1880                 ndc.ndtc_hash_rnd = nht->hash_rnd[0];
1881                 ndc.ndtc_hash_mask = ((1 << nht->hash_shift) - 1);
1882                 rcu_read_unlock_bh();
1883
1884                 if (nla_put(skb, NDTA_CONFIG, sizeof(ndc), &ndc))
1885                         goto nla_put_failure;
1886         }
1887
1888         {
1889                 int cpu;
1890                 struct ndt_stats ndst;
1891
1892                 memset(&ndst, 0, sizeof(ndst));
1893
1894                 for_each_possible_cpu(cpu) {
1895                         struct neigh_statistics *st;
1896
1897                         st = per_cpu_ptr(tbl->stats, cpu);
1898                         ndst.ndts_allocs                += st->allocs;
1899                         ndst.ndts_destroys              += st->destroys;
1900                         ndst.ndts_hash_grows            += st->hash_grows;
1901                         ndst.ndts_res_failed            += st->res_failed;
1902                         ndst.ndts_lookups               += st->lookups;
1903                         ndst.ndts_hits                  += st->hits;
1904                         ndst.ndts_rcv_probes_mcast      += st->rcv_probes_mcast;
1905                         ndst.ndts_rcv_probes_ucast      += st->rcv_probes_ucast;
1906                         ndst.ndts_periodic_gc_runs      += st->periodic_gc_runs;
1907                         ndst.ndts_forced_gc_runs        += st->forced_gc_runs;
1908                 }
1909
1910                 if (nla_put(skb, NDTA_STATS, sizeof(ndst), &ndst))
1911                         goto nla_put_failure;
1912         }
1913
1914         BUG_ON(tbl->parms.dev);
1915         if (neightbl_fill_parms(skb, &tbl->parms) < 0)
1916                 goto nla_put_failure;
1917
1918         read_unlock_bh(&tbl->lock);
1919         return nlmsg_end(skb, nlh);
1920
1921 nla_put_failure:
1922         read_unlock_bh(&tbl->lock);
1923         nlmsg_cancel(skb, nlh);
1924         return -EMSGSIZE;
1925 }
1926
1927 static int neightbl_fill_param_info(struct sk_buff *skb,
1928                                     struct neigh_table *tbl,
1929                                     struct neigh_parms *parms,
1930                                     u32 pid, u32 seq, int type,
1931                                     unsigned int flags)
1932 {
1933         struct ndtmsg *ndtmsg;
1934         struct nlmsghdr *nlh;
1935
1936         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
1937         if (nlh == NULL)
1938                 return -EMSGSIZE;
1939
1940         ndtmsg = nlmsg_data(nlh);
1941
1942         read_lock_bh(&tbl->lock);
1943         ndtmsg->ndtm_family = tbl->family;
1944         ndtmsg->ndtm_pad1   = 0;
1945         ndtmsg->ndtm_pad2   = 0;
1946
1947         if (nla_put_string(skb, NDTA_NAME, tbl->id) < 0 ||
1948             neightbl_fill_parms(skb, parms) < 0)
1949                 goto errout;
1950
1951         read_unlock_bh(&tbl->lock);
1952         return nlmsg_end(skb, nlh);
1953 errout:
1954         read_unlock_bh(&tbl->lock);
1955         nlmsg_cancel(skb, nlh);
1956         return -EMSGSIZE;
1957 }
1958
1959 static const struct nla_policy nl_neightbl_policy[NDTA_MAX+1] = {
1960         [NDTA_NAME]             = { .type = NLA_STRING },
1961         [NDTA_THRESH1]          = { .type = NLA_U32 },
1962         [NDTA_THRESH2]          = { .type = NLA_U32 },
1963         [NDTA_THRESH3]          = { .type = NLA_U32 },
1964         [NDTA_GC_INTERVAL]      = { .type = NLA_U64 },
1965         [NDTA_PARMS]            = { .type = NLA_NESTED },
1966 };
1967
1968 static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
1969         [NDTPA_IFINDEX]                 = { .type = NLA_U32 },
1970         [NDTPA_QUEUE_LEN]               = { .type = NLA_U32 },
1971         [NDTPA_PROXY_QLEN]              = { .type = NLA_U32 },
1972         [NDTPA_APP_PROBES]              = { .type = NLA_U32 },
1973         [NDTPA_UCAST_PROBES]            = { .type = NLA_U32 },
1974         [NDTPA_MCAST_PROBES]            = { .type = NLA_U32 },
1975         [NDTPA_BASE_REACHABLE_TIME]     = { .type = NLA_U64 },
1976         [NDTPA_GC_STALETIME]            = { .type = NLA_U64 },
1977         [NDTPA_DELAY_PROBE_TIME]        = { .type = NLA_U64 },
1978         [NDTPA_RETRANS_TIME]            = { .type = NLA_U64 },
1979         [NDTPA_ANYCAST_DELAY]           = { .type = NLA_U64 },
1980         [NDTPA_PROXY_DELAY]             = { .type = NLA_U64 },
1981         [NDTPA_LOCKTIME]                = { .type = NLA_U64 },
1982 };
1983
1984 static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh)
1985 {
1986         struct net *net = sock_net(skb->sk);
1987         struct neigh_table *tbl;
1988         struct ndtmsg *ndtmsg;
1989         struct nlattr *tb[NDTA_MAX+1];
1990         int err;
1991
1992         err = nlmsg_parse(nlh, sizeof(*ndtmsg), tb, NDTA_MAX,
1993                           nl_neightbl_policy);
1994         if (err < 0)
1995                 goto errout;
1996
1997         if (tb[NDTA_NAME] == NULL) {
1998                 err = -EINVAL;
1999                 goto errout;
2000         }
2001
2002         ndtmsg = nlmsg_data(nlh);
2003         read_lock(&neigh_tbl_lock);
2004         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
2005                 if (ndtmsg->ndtm_family && tbl->family != ndtmsg->ndtm_family)
2006                         continue;
2007
2008                 if (nla_strcmp(tb[NDTA_NAME], tbl->id) == 0)
2009                         break;
2010         }
2011
2012         if (tbl == NULL) {
2013                 err = -ENOENT;
2014                 goto errout_locked;
2015         }
2016
2017         /*
2018          * We acquire tbl->lock to be nice to the periodic timers and
2019          * make sure they always see a consistent set of values.
2020          */
2021         write_lock_bh(&tbl->lock);
2022
2023         if (tb[NDTA_PARMS]) {
2024                 struct nlattr *tbp[NDTPA_MAX+1];
2025                 struct neigh_parms *p;
2026                 int i, ifindex = 0;
2027
2028                 err = nla_parse_nested(tbp, NDTPA_MAX, tb[NDTA_PARMS],
2029                                        nl_ntbl_parm_policy);
2030                 if (err < 0)
2031                         goto errout_tbl_lock;
2032
2033                 if (tbp[NDTPA_IFINDEX])
2034                         ifindex = nla_get_u32(tbp[NDTPA_IFINDEX]);
2035
2036                 p = lookup_neigh_parms(tbl, net, ifindex);
2037                 if (p == NULL) {
2038                         err = -ENOENT;
2039                         goto errout_tbl_lock;
2040                 }
2041
2042                 for (i = 1; i <= NDTPA_MAX; i++) {
2043                         if (tbp[i] == NULL)
2044                                 continue;
2045
2046                         switch (i) {
2047                         case NDTPA_QUEUE_LEN:
2048                                 NEIGH_VAR_SET(p, QUEUE_LEN_BYTES,
2049                                               nla_get_u32(tbp[i]) *
2050                                               SKB_TRUESIZE(ETH_FRAME_LEN));
2051                                 break;
2052                         case NDTPA_QUEUE_LENBYTES:
2053                                 NEIGH_VAR_SET(p, QUEUE_LEN_BYTES,
2054                                               nla_get_u32(tbp[i]));
2055                                 break;
2056                         case NDTPA_PROXY_QLEN:
2057                                 NEIGH_VAR_SET(p, PROXY_QLEN,
2058                                               nla_get_u32(tbp[i]));
2059                                 break;
2060                         case NDTPA_APP_PROBES:
2061                                 NEIGH_VAR_SET(p, APP_PROBES,
2062                                               nla_get_u32(tbp[i]));
2063                                 break;
2064                         case NDTPA_UCAST_PROBES:
2065                                 NEIGH_VAR_SET(p, UCAST_PROBES,
2066                                               nla_get_u32(tbp[i]));
2067                                 break;
2068                         case NDTPA_MCAST_PROBES:
2069                                 NEIGH_VAR_SET(p, MCAST_PROBES,
2070                                               nla_get_u32(tbp[i]));
2071                                 break;
2072                         case NDTPA_BASE_REACHABLE_TIME:
2073                                 NEIGH_VAR_SET(p, BASE_REACHABLE_TIME,
2074                                               nla_get_msecs(tbp[i]));
2075                                 break;
2076                         case NDTPA_GC_STALETIME:
2077                                 NEIGH_VAR_SET(p, GC_STALETIME,
2078                                               nla_get_msecs(tbp[i]));
2079                                 break;
2080                         case NDTPA_DELAY_PROBE_TIME:
2081                                 NEIGH_VAR_SET(p, DELAY_PROBE_TIME,
2082                                               nla_get_msecs(tbp[i]));
2083                                 break;
2084                         case NDTPA_RETRANS_TIME:
2085                                 NEIGH_VAR_SET(p, RETRANS_TIME,
2086                                               nla_get_msecs(tbp[i]));
2087                                 break;
2088                         case NDTPA_ANYCAST_DELAY:
2089                                 NEIGH_VAR_SET(p, ANYCAST_DELAY, nla_get_msecs(tbp[i]));
2090                                 break;
2091                         case NDTPA_PROXY_DELAY:
2092                                 NEIGH_VAR_SET(p, PROXY_DELAY, nla_get_msecs(tbp[i]));
2093                                 break;
2094                         case NDTPA_LOCKTIME:
2095                                 NEIGH_VAR_SET(p, LOCKTIME, nla_get_msecs(tbp[i]));
2096                                 break;
2097                         }
2098                 }
2099         }
2100
2101         err = -ENOENT;
2102         if ((tb[NDTA_THRESH1] || tb[NDTA_THRESH2] ||
2103              tb[NDTA_THRESH3] || tb[NDTA_GC_INTERVAL]) &&
2104             !net_eq(net, &init_net))
2105                 goto errout_tbl_lock;
2106
2107         if (tb[NDTA_THRESH1])
2108                 tbl->gc_thresh1 = nla_get_u32(tb[NDTA_THRESH1]);
2109
2110         if (tb[NDTA_THRESH2])
2111                 tbl->gc_thresh2 = nla_get_u32(tb[NDTA_THRESH2]);
2112
2113         if (tb[NDTA_THRESH3])
2114                 tbl->gc_thresh3 = nla_get_u32(tb[NDTA_THRESH3]);
2115
2116         if (tb[NDTA_GC_INTERVAL])
2117                 tbl->gc_interval = nla_get_msecs(tb[NDTA_GC_INTERVAL]);
2118
2119         err = 0;
2120
2121 errout_tbl_lock:
2122         write_unlock_bh(&tbl->lock);
2123 errout_locked:
2124         read_unlock(&neigh_tbl_lock);
2125 errout:
2126         return err;
2127 }
2128
2129 static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2130 {
2131         struct net *net = sock_net(skb->sk);
2132         int family, tidx, nidx = 0;
2133         int tbl_skip = cb->args[0];
2134         int neigh_skip = cb->args[1];
2135         struct neigh_table *tbl;
2136
2137         family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;
2138
2139         read_lock(&neigh_tbl_lock);
2140         for (tbl = neigh_tables, tidx = 0; tbl; tbl = tbl->next, tidx++) {
2141                 struct neigh_parms *p;
2142
2143                 if (tidx < tbl_skip || (family && tbl->family != family))
2144                         continue;
2145
2146                 if (neightbl_fill_info(skb, tbl, NETLINK_CB(cb->skb).portid,
2147                                        cb->nlh->nlmsg_seq, RTM_NEWNEIGHTBL,
2148                                        NLM_F_MULTI) <= 0)
2149                         break;
2150
2151                 for (nidx = 0, p = tbl->parms.next; p; p = p->next) {
2152                         if (!net_eq(neigh_parms_net(p), net))
2153                                 continue;
2154
2155                         if (nidx < neigh_skip)
2156                                 goto next;
2157
2158                         if (neightbl_fill_param_info(skb, tbl, p,
2159                                                      NETLINK_CB(cb->skb).portid,
2160                                                      cb->nlh->nlmsg_seq,
2161                                                      RTM_NEWNEIGHTBL,
2162                                                      NLM_F_MULTI) <= 0)
2163                                 goto out;
2164                 next:
2165                         nidx++;
2166                 }
2167
2168                 neigh_skip = 0;
2169         }
2170 out:
2171         read_unlock(&neigh_tbl_lock);
2172         cb->args[0] = tidx;
2173         cb->args[1] = nidx;
2174
2175         return skb->len;
2176 }
2177
2178 static int neigh_fill_info(struct sk_buff *skb, struct neighbour *neigh,
2179                            u32 pid, u32 seq, int type, unsigned int flags)
2180 {
2181         unsigned long now = jiffies;
2182         struct nda_cacheinfo ci;
2183         struct nlmsghdr *nlh;
2184         struct ndmsg *ndm;
2185
2186         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
2187         if (nlh == NULL)
2188                 return -EMSGSIZE;
2189
2190         ndm = nlmsg_data(nlh);
2191         ndm->ndm_family  = neigh->ops->family;
2192         ndm->ndm_pad1    = 0;
2193         ndm->ndm_pad2    = 0;
2194         ndm->ndm_flags   = neigh->flags;
2195         ndm->ndm_type    = neigh->type;
2196         ndm->ndm_ifindex = neigh->dev->ifindex;
2197
2198         if (nla_put(skb, NDA_DST, neigh->tbl->key_len, neigh->primary_key))
2199                 goto nla_put_failure;
2200
2201         read_lock_bh(&neigh->lock);
2202         ndm->ndm_state   = neigh->nud_state;
2203         if (neigh->nud_state & NUD_VALID) {
2204                 char haddr[MAX_ADDR_LEN];
2205
2206                 neigh_ha_snapshot(haddr, neigh, neigh->dev);
2207                 if (nla_put(skb, NDA_LLADDR, neigh->dev->addr_len, haddr) < 0) {
2208                         read_unlock_bh(&neigh->lock);
2209                         goto nla_put_failure;
2210                 }
2211         }
2212
2213         ci.ndm_used      = jiffies_to_clock_t(now - neigh->used);
2214         ci.ndm_confirmed = jiffies_to_clock_t(now - neigh->confirmed);
2215         ci.ndm_updated   = jiffies_to_clock_t(now - neigh->updated);
2216         ci.ndm_refcnt    = atomic_read(&neigh->refcnt) - 1;
2217         read_unlock_bh(&neigh->lock);
2218
2219         if (nla_put_u32(skb, NDA_PROBES, atomic_read(&neigh->probes)) ||
2220             nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
2221                 goto nla_put_failure;
2222
2223         return nlmsg_end(skb, nlh);
2224
2225 nla_put_failure:
2226         nlmsg_cancel(skb, nlh);
2227         return -EMSGSIZE;
2228 }
2229
2230 static int pneigh_fill_info(struct sk_buff *skb, struct pneigh_entry *pn,
2231                             u32 pid, u32 seq, int type, unsigned int flags,
2232                             struct neigh_table *tbl)
2233 {
2234         struct nlmsghdr *nlh;
2235         struct ndmsg *ndm;
2236
2237         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
2238         if (nlh == NULL)
2239                 return -EMSGSIZE;
2240
2241         ndm = nlmsg_data(nlh);
2242         ndm->ndm_family  = tbl->family;
2243         ndm->ndm_pad1    = 0;
2244         ndm->ndm_pad2    = 0;
2245         ndm->ndm_flags   = pn->flags | NTF_PROXY;
2246         ndm->ndm_type    = NDA_DST;
2247         ndm->ndm_ifindex = pn->dev->ifindex;
2248         ndm->ndm_state   = NUD_NONE;
2249
2250         if (nla_put(skb, NDA_DST, tbl->key_len, pn->key))
2251                 goto nla_put_failure;
2252
2253         return nlmsg_end(skb, nlh);
2254
2255 nla_put_failure:
2256         nlmsg_cancel(skb, nlh);
2257         return -EMSGSIZE;
2258 }
2259
2260 static void neigh_update_notify(struct neighbour *neigh)
2261 {
2262         call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
2263         __neigh_notify(neigh, RTM_NEWNEIGH, 0);
2264 }
2265
2266 static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
2267                             struct netlink_callback *cb)
2268 {
2269         struct net *net = sock_net(skb->sk);
2270         struct neighbour *n;
2271         int rc, h, s_h = cb->args[1];
2272         int idx, s_idx = idx = cb->args[2];
2273         struct neigh_hash_table *nht;
2274
2275         rcu_read_lock_bh();
2276         nht = rcu_dereference_bh(tbl->nht);
2277
2278         for (h = s_h; h < (1 << nht->hash_shift); h++) {
2279                 if (h > s_h)
2280                         s_idx = 0;
2281                 for (n = rcu_dereference_bh(nht->hash_buckets[h]), idx = 0;
2282                      n != NULL;
2283                      n = rcu_dereference_bh(n->next)) {
2284                         if (!net_eq(dev_net(n->dev), net))
2285                                 continue;
2286                         if (idx < s_idx)
2287                                 goto next;
2288                         if (neigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,
2289                                             cb->nlh->nlmsg_seq,
2290                                             RTM_NEWNEIGH,
2291                                             NLM_F_MULTI) <= 0) {
2292                                 rc = -1;
2293                                 goto out;
2294                         }
2295 next:
2296                         idx++;
2297                 }
2298         }
2299         rc = skb->len;
2300 out:
2301         rcu_read_unlock_bh();
2302         cb->args[1] = h;
2303         cb->args[2] = idx;
2304         return rc;
2305 }
2306
2307 static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
2308                              struct netlink_callback *cb)
2309 {
2310         struct pneigh_entry *n;
2311         struct net *net = sock_net(skb->sk);
2312         int rc, h, s_h = cb->args[3];
2313         int idx, s_idx = idx = cb->args[4];
2314
2315         read_lock_bh(&tbl->lock);
2316
2317         for (h = s_h; h <= PNEIGH_HASHMASK; h++) {
2318                 if (h > s_h)
2319                         s_idx = 0;
2320                 for (n = tbl->phash_buckets[h], idx = 0; n; n = n->next) {
2321                         if (dev_net(n->dev) != net)
2322                                 continue;
2323                         if (idx < s_idx)
2324                                 goto next;
2325                         if (pneigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,
2326                                             cb->nlh->nlmsg_seq,
2327                                             RTM_NEWNEIGH,
2328                                             NLM_F_MULTI, tbl) <= 0) {
2329                                 read_unlock_bh(&tbl->lock);
2330                                 rc = -1;
2331                                 goto out;
2332                         }
2333                 next:
2334                         idx++;
2335                 }
2336         }
2337
2338         read_unlock_bh(&tbl->lock);
2339         rc = skb->len;
2340 out:
2341         cb->args[3] = h;
2342         cb->args[4] = idx;
2343         return rc;
2344
2345 }
2346
2347 static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2348 {
2349         struct neigh_table *tbl;
2350         int t, family, s_t;
2351         int proxy = 0;
2352         int err;
2353
2354         read_lock(&neigh_tbl_lock);
2355         family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;
2356
2357         /* check for full ndmsg structure presence, family member is
2358          * the same for both structures
2359          */
2360         if (nlmsg_len(cb->nlh) >= sizeof(struct ndmsg) &&
2361             ((struct ndmsg *) nlmsg_data(cb->nlh))->ndm_flags == NTF_PROXY)
2362                 proxy = 1;
2363
2364         s_t = cb->args[0];
2365
2366         for (tbl = neigh_tables, t = 0; tbl;
2367              tbl = tbl->next, t++) {
2368                 if (t < s_t || (family && tbl->family != family))
2369                         continue;
2370                 if (t > s_t)
2371                         memset(&cb->args[1], 0, sizeof(cb->args) -
2372                                                 sizeof(cb->args[0]));
2373                 if (proxy)
2374                         err = pneigh_dump_table(tbl, skb, cb);
2375                 else
2376                         err = neigh_dump_table(tbl, skb, cb);
2377                 if (err < 0)
2378                         break;
2379         }
2380         read_unlock(&neigh_tbl_lock);
2381
2382         cb->args[0] = t;
2383         return skb->len;
2384 }
2385
2386 void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie)
2387 {
2388         int chain;
2389         struct neigh_hash_table *nht;
2390
2391         rcu_read_lock_bh();
2392         nht = rcu_dereference_bh(tbl->nht);
2393
2394         read_lock(&tbl->lock); /* avoid resizes */
2395         for (chain = 0; chain < (1 << nht->hash_shift); chain++) {
2396                 struct neighbour *n;
2397
2398                 for (n = rcu_dereference_bh(nht->hash_buckets[chain]);
2399                      n != NULL;
2400                      n = rcu_dereference_bh(n->next))
2401                         cb(n, cookie);
2402         }
2403         read_unlock(&tbl->lock);
2404         rcu_read_unlock_bh();
2405 }
2406 EXPORT_SYMBOL(neigh_for_each);
2407
2408 /* The tbl->lock must be held as a writer and BH disabled. */
2409 void __neigh_for_each_release(struct neigh_table *tbl,
2410                               int (*cb)(struct neighbour *))
2411 {
2412         int chain;
2413         struct neigh_hash_table *nht;
2414
2415         nht = rcu_dereference_protected(tbl->nht,
2416                                         lockdep_is_held(&tbl->lock));
2417         for (chain = 0; chain < (1 << nht->hash_shift); chain++) {
2418                 struct neighbour *n;
2419                 struct neighbour __rcu **np;
2420
2421                 np = &nht->hash_buckets[chain];
2422                 while ((n = rcu_dereference_protected(*np,
2423                                         lockdep_is_held(&tbl->lock))) != NULL) {
2424                         int release;
2425
2426                         write_lock(&n->lock);
2427                         release = cb(n);
2428                         if (release) {
2429                                 rcu_assign_pointer(*np,
2430                                         rcu_dereference_protected(n->next,
2431                                                 lockdep_is_held(&tbl->lock)));
2432                                 n->dead = 1;
2433                         } else
2434                                 np = &n->next;
2435                         write_unlock(&n->lock);
2436                         if (release)
2437                                 neigh_cleanup_and_release(n);
2438                 }
2439         }
2440 }
2441 EXPORT_SYMBOL(__neigh_for_each_release);
2442
2443 #ifdef CONFIG_PROC_FS
2444
2445 static struct neighbour *neigh_get_first(struct seq_file *seq)
2446 {
2447         struct neigh_seq_state *state = seq->private;
2448         struct net *net = seq_file_net(seq);
2449         struct neigh_hash_table *nht = state->nht;
2450         struct neighbour *n = NULL;
2451         int bucket = state->bucket;
2452
2453         state->flags &= ~NEIGH_SEQ_IS_PNEIGH;
2454         for (bucket = 0; bucket < (1 << nht->hash_shift); bucket++) {
2455                 n = rcu_dereference_bh(nht->hash_buckets[bucket]);
2456
2457                 while (n) {
2458                         if (!net_eq(dev_net(n->dev), net))
2459                                 goto next;
2460                         if (state->neigh_sub_iter) {
2461                                 loff_t fakep = 0;
2462                                 void *v;
2463
2464                                 v = state->neigh_sub_iter(state, n, &fakep);
2465                                 if (!v)
2466                                         goto next;
2467                         }
2468                         if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
2469                                 break;
2470                         if (n->nud_state & ~NUD_NOARP)
2471                                 break;
2472 next:
2473                         n = rcu_dereference_bh(n->next);
2474                 }
2475
2476                 if (n)
2477                         break;
2478         }
2479         state->bucket = bucket;
2480
2481         return n;
2482 }
2483
2484 static struct neighbour *neigh_get_next(struct seq_file *seq,
2485                                         struct neighbour *n,
2486                                         loff_t *pos)
2487 {
2488         struct neigh_seq_state *state = seq->private;
2489         struct net *net = seq_file_net(seq);
2490         struct neigh_hash_table *nht = state->nht;
2491
2492         if (state->neigh_sub_iter) {
2493                 void *v = state->neigh_sub_iter(state, n, pos);
2494                 if (v)
2495                         return n;
2496         }
2497         n = rcu_dereference_bh(n->next);
2498
2499         while (1) {
2500                 while (n) {
2501                         if (!net_eq(dev_net(n->dev), net))
2502                                 goto next;
2503                         if (state->neigh_sub_iter) {
2504                                 void *v = state->neigh_sub_iter(state, n, pos);
2505                                 if (v)
2506                                         return n;
2507                                 goto next;
2508                         }
2509                         if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
2510                                 break;
2511
2512                         if (n->nud_state & ~NUD_NOARP)
2513                                 break;
2514 next:
2515                         n = rcu_dereference_bh(n->next);
2516                 }
2517
2518                 if (n)
2519                         break;
2520
2521                 if (++state->bucket >= (1 << nht->hash_shift))
2522                         break;
2523
2524                 n = rcu_dereference_bh(nht->hash_buckets[state->bucket]);
2525         }
2526
2527         if (n && pos)
2528                 --(*pos);
2529         return n;
2530 }
2531
2532 static struct neighbour *neigh_get_idx(struct seq_file *seq, loff_t *pos)
2533 {
2534         struct neighbour *n = neigh_get_first(seq);
2535
2536         if (n) {
2537                 --(*pos);
2538                 while (*pos) {
2539                         n = neigh_get_next(seq, n, pos);
2540                         if (!n)
2541                                 break;
2542                 }
2543         }
2544         return *pos ? NULL : n;
2545 }
2546
2547 static struct pneigh_entry *pneigh_get_first(struct seq_file *seq)
2548 {
2549         struct neigh_seq_state *state = seq->private;
2550         struct net *net = seq_file_net(seq);
2551         struct neigh_table *tbl = state->tbl;
2552         struct pneigh_entry *pn = NULL;
2553         int bucket = state->bucket;
2554
2555         state->flags |= NEIGH_SEQ_IS_PNEIGH;
2556         for (bucket = 0; bucket <= PNEIGH_HASHMASK; bucket++) {
2557                 pn = tbl->phash_buckets[bucket];
2558                 while (pn && !net_eq(pneigh_net(pn), net))
2559                         pn = pn->next;
2560                 if (pn)
2561                         break;
2562         }
2563         state->bucket = bucket;
2564
2565         return pn;
2566 }
2567
2568 static struct pneigh_entry *pneigh_get_next(struct seq_file *seq,
2569                                             struct pneigh_entry *pn,
2570                                             loff_t *pos)
2571 {
2572         struct neigh_seq_state *state = seq->private;
2573         struct net *net = seq_file_net(seq);
2574         struct neigh_table *tbl = state->tbl;
2575
2576         do {
2577                 pn = pn->next;
2578         } while (pn && !net_eq(pneigh_net(pn), net));
2579
2580         while (!pn) {
2581                 if (++state->bucket > PNEIGH_HASHMASK)
2582                         break;
2583                 pn = tbl->phash_buckets[state->bucket];
2584                 while (pn && !net_eq(pneigh_net(pn), net))
2585                         pn = pn->next;
2586                 if (pn)
2587                         break;
2588         }
2589
2590         if (pn && pos)
2591                 --(*pos);
2592
2593         return pn;
2594 }
2595
2596 static struct pneigh_entry *pneigh_get_idx(struct seq_file *seq, loff_t *pos)
2597 {
2598         struct pneigh_entry *pn = pneigh_get_first(seq);
2599
2600         if (pn) {
2601                 --(*pos);
2602                 while (*pos) {
2603                         pn = pneigh_get_next(seq, pn, pos);
2604                         if (!pn)
2605                                 break;
2606                 }
2607         }
2608         return *pos ? NULL : pn;
2609 }
2610
2611 static void *neigh_get_idx_any(struct seq_file *seq, loff_t *pos)
2612 {
2613         struct neigh_seq_state *state = seq->private;
2614         void *rc;
2615         loff_t idxpos = *pos;
2616
2617         rc = neigh_get_idx(seq, &idxpos);
2618         if (!rc && !(state->flags & NEIGH_SEQ_NEIGH_ONLY))
2619                 rc = pneigh_get_idx(seq, &idxpos);
2620
2621         return rc;
2622 }
2623
2624 void *neigh_seq_start(struct seq_file *seq, loff_t *pos, struct neigh_table *tbl, unsigned int neigh_seq_flags)
2625         __acquires(rcu_bh)
2626 {
2627         struct neigh_seq_state *state = seq->private;
2628
2629         state->tbl = tbl;
2630         state->bucket = 0;
2631         state->flags = (neigh_seq_flags & ~NEIGH_SEQ_IS_PNEIGH);
2632
2633         rcu_read_lock_bh();
2634         state->nht = rcu_dereference_bh(tbl->nht);
2635
2636         return *pos ? neigh_get_idx_any(seq, pos) : SEQ_START_TOKEN;
2637 }
2638 EXPORT_SYMBOL(neigh_seq_start);
2639
2640 void *neigh_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2641 {
2642         struct neigh_seq_state *state;
2643         void *rc;
2644
2645         if (v == SEQ_START_TOKEN) {
2646                 rc = neigh_get_first(seq);
2647                 goto out;
2648         }
2649
2650         state = seq->private;
2651         if (!(state->flags & NEIGH_SEQ_IS_PNEIGH)) {
2652                 rc = neigh_get_next(seq, v, NULL);
2653                 if (rc)
2654                         goto out;
2655                 if (!(state->flags & NEIGH_SEQ_NEIGH_ONLY))
2656                         rc = pneigh_get_first(seq);
2657         } else {
2658                 BUG_ON(state->flags & NEIGH_SEQ_NEIGH_ONLY);
2659                 rc = pneigh_get_next(seq, v, NULL);
2660         }
2661 out:
2662         ++(*pos);
2663         return rc;
2664 }
2665 EXPORT_SYMBOL(neigh_seq_next);
2666
2667 void neigh_seq_stop(struct seq_file *seq, void *v)
2668         __releases(rcu_bh)
2669 {
2670         rcu_read_unlock_bh();
2671 }
2672 EXPORT_SYMBOL(neigh_seq_stop);
2673
2674 /* statistics via seq_file */
2675
2676 static void *neigh_stat_seq_start(struct seq_file *seq, loff_t *pos)
2677 {
2678         struct neigh_table *tbl = seq->private;
2679         int cpu;
2680
2681         if (*pos == 0)
2682                 return SEQ_START_TOKEN;
2683
2684         for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
2685                 if (!cpu_possible(cpu))
2686                         continue;
2687                 *pos = cpu+1;
2688                 return per_cpu_ptr(tbl->stats, cpu);
2689         }
2690         return NULL;
2691 }
2692
2693 static void *neigh_stat_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2694 {
2695         struct neigh_table *tbl = seq->private;
2696         int cpu;
2697
2698         for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
2699                 if (!cpu_possible(cpu))
2700                         continue;
2701                 *pos = cpu+1;
2702                 return per_cpu_ptr(tbl->stats, cpu);
2703         }
2704         return NULL;
2705 }
2706
2707 static void neigh_stat_seq_stop(struct seq_file *seq, void *v)
2708 {
2709
2710 }
2711
2712 static int neigh_stat_seq_show(struct seq_file *seq, void *v)
2713 {
2714         struct neigh_table *tbl = seq->private;
2715         struct neigh_statistics *st = v;
2716
2717         if (v == SEQ_START_TOKEN) {
2718                 seq_printf(seq, "entries  allocs destroys hash_grows  lookups hits  res_failed  rcv_probes_mcast rcv_probes_ucast  periodic_gc_runs forced_gc_runs unresolved_discards\n");
2719                 return 0;
2720         }
2721
2722         seq_printf(seq, "%08x  %08lx %08lx %08lx  %08lx %08lx  %08lx  "
2723                         "%08lx %08lx  %08lx %08lx %08lx\n",
2724                    atomic_read(&tbl->entries),
2725
2726                    st->allocs,
2727                    st->destroys,
2728                    st->hash_grows,
2729
2730                    st->lookups,
2731                    st->hits,
2732
2733                    st->res_failed,
2734
2735                    st->rcv_probes_mcast,
2736                    st->rcv_probes_ucast,
2737
2738                    st->periodic_gc_runs,
2739                    st->forced_gc_runs,
2740                    st->unres_discards
2741                    );
2742
2743         return 0;
2744 }
2745
2746 static const struct seq_operations neigh_stat_seq_ops = {
2747         .start  = neigh_stat_seq_start,
2748         .next   = neigh_stat_seq_next,
2749         .stop   = neigh_stat_seq_stop,
2750         .show   = neigh_stat_seq_show,
2751 };
2752
2753 static int neigh_stat_seq_open(struct inode *inode, struct file *file)
2754 {
2755         int ret = seq_open(file, &neigh_stat_seq_ops);
2756
2757         if (!ret) {
2758                 struct seq_file *sf = file->private_data;
2759                 sf->private = PDE_DATA(inode);
2760         }
2761         return ret;
2762 };
2763
2764 static const struct file_operations neigh_stat_seq_fops = {
2765         .owner   = THIS_MODULE,
2766         .open    = neigh_stat_seq_open,
2767         .read    = seq_read,
2768         .llseek  = seq_lseek,
2769         .release = seq_release,
2770 };
2771
2772 #endif /* CONFIG_PROC_FS */
2773
2774 static inline size_t neigh_nlmsg_size(void)
2775 {
2776         return NLMSG_ALIGN(sizeof(struct ndmsg))
2777                + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
2778                + nla_total_size(MAX_ADDR_LEN) /* NDA_LLADDR */
2779                + nla_total_size(sizeof(struct nda_cacheinfo))
2780                + nla_total_size(4); /* NDA_PROBES */
2781 }
2782
2783 static void __neigh_notify(struct neighbour *n, int type, int flags)
2784 {
2785         struct net *net = dev_net(n->dev);
2786         struct sk_buff *skb;
2787         int err = -ENOBUFS;
2788
2789         skb = nlmsg_new(neigh_nlmsg_size(), GFP_ATOMIC);
2790         if (skb == NULL)
2791                 goto errout;
2792
2793         err = neigh_fill_info(skb, n, 0, 0, type, flags);
2794         if (err < 0) {
2795                 /* -EMSGSIZE implies BUG in neigh_nlmsg_size() */
2796                 WARN_ON(err == -EMSGSIZE);
2797                 kfree_skb(skb);
2798                 goto errout;
2799         }
2800         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
2801         return;
2802 errout:
2803         if (err < 0)
2804                 rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
2805 }
2806
2807 void neigh_app_ns(struct neighbour *n)
2808 {
2809         __neigh_notify(n, RTM_GETNEIGH, NLM_F_REQUEST);
2810 }
2811 EXPORT_SYMBOL(neigh_app_ns);
2812
2813 #ifdef CONFIG_SYSCTL
2814 static int zero;
2815 static int int_max = INT_MAX;
2816 static int unres_qlen_max = INT_MAX / SKB_TRUESIZE(ETH_FRAME_LEN);
2817
2818 static int proc_unres_qlen(struct ctl_table *ctl, int write,
2819                            void __user *buffer, size_t *lenp, loff_t *ppos)
2820 {
2821         int size, ret;
2822         struct ctl_table tmp = *ctl;
2823
2824         tmp.extra1 = &zero;
2825         tmp.extra2 = &unres_qlen_max;
2826         tmp.data = &size;
2827
2828         size = *(int *)ctl->data / SKB_TRUESIZE(ETH_FRAME_LEN);
2829         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2830
2831         if (write && !ret)
2832                 *(int *)ctl->data = size * SKB_TRUESIZE(ETH_FRAME_LEN);
2833         return ret;
2834 }
2835
2836 static struct neigh_parms *neigh_get_dev_parms_rcu(struct net_device *dev,
2837                                                    int family)
2838 {
2839         switch (family) {
2840         case AF_INET:
2841                 return __in_dev_arp_parms_get_rcu(dev);
2842         case AF_INET6:
2843                 return __in6_dev_nd_parms_get_rcu(dev);
2844         }
2845         return NULL;
2846 }
2847
2848 static void neigh_copy_dflt_parms(struct net *net, struct neigh_parms *p,
2849                                   int index)
2850 {
2851         struct net_device *dev;
2852         int family = neigh_parms_family(p);
2853
2854         rcu_read_lock();
2855         for_each_netdev_rcu(net, dev) {
2856                 struct neigh_parms *dst_p =
2857                                 neigh_get_dev_parms_rcu(dev, family);
2858
2859                 if (dst_p && !test_bit(index, dst_p->data_state))
2860                         dst_p->data[index] = p->data[index];
2861         }
2862         rcu_read_unlock();
2863 }
2864
2865 static void neigh_proc_update(struct ctl_table *ctl, int write)
2866 {
2867         struct net_device *dev = ctl->extra1;
2868         struct neigh_parms *p = ctl->extra2;
2869         struct net *net = neigh_parms_net(p);
2870         int index = (int *) ctl->data - p->data;
2871
2872         if (!write)
2873                 return;
2874
2875         set_bit(index, p->data_state);
2876         if (!dev) /* NULL dev means this is default value */
2877                 neigh_copy_dflt_parms(net, p, index);
2878 }
2879
2880 static int neigh_proc_dointvec_zero_intmax(struct ctl_table *ctl, int write,
2881                                            void __user *buffer,
2882                                            size_t *lenp, loff_t *ppos)
2883 {
2884         struct ctl_table tmp = *ctl;
2885         int ret;
2886
2887         tmp.extra1 = &zero;
2888         tmp.extra2 = &int_max;
2889
2890         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2891         neigh_proc_update(ctl, write);
2892         return ret;
2893 }
2894
2895 int neigh_proc_dointvec(struct ctl_table *ctl, int write,
2896                         void __user *buffer, size_t *lenp, loff_t *ppos)
2897 {
2898         int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
2899
2900         neigh_proc_update(ctl, write);
2901         return ret;
2902 }
2903 EXPORT_SYMBOL(neigh_proc_dointvec);
2904
2905 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
2906                                 void __user *buffer,
2907                                 size_t *lenp, loff_t *ppos)
2908 {
2909         int ret = proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos);
2910
2911         neigh_proc_update(ctl, write);
2912         return ret;
2913 }
2914 EXPORT_SYMBOL(neigh_proc_dointvec_jiffies);
2915
2916 static int neigh_proc_dointvec_userhz_jiffies(struct ctl_table *ctl, int write,
2917                                               void __user *buffer,
2918                                               size_t *lenp, loff_t *ppos)
2919 {
2920         int ret = proc_dointvec_userhz_jiffies(ctl, write, buffer, lenp, ppos);
2921
2922         neigh_proc_update(ctl, write);
2923         return ret;
2924 }
2925
2926 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
2927                                    void __user *buffer,
2928                                    size_t *lenp, loff_t *ppos)
2929 {
2930         int ret = proc_dointvec_ms_jiffies(ctl, write, buffer, lenp, ppos);
2931
2932         neigh_proc_update(ctl, write);
2933         return ret;
2934 }
2935 EXPORT_SYMBOL(neigh_proc_dointvec_ms_jiffies);
2936
2937 static int neigh_proc_dointvec_unres_qlen(struct ctl_table *ctl, int write,
2938                                           void __user *buffer,
2939                                           size_t *lenp, loff_t *ppos)
2940 {
2941         int ret = proc_unres_qlen(ctl, write, buffer, lenp, ppos);
2942
2943         neigh_proc_update(ctl, write);
2944         return ret;
2945 }
2946
2947 #define NEIGH_PARMS_DATA_OFFSET(index)  \
2948         (&((struct neigh_parms *) 0)->data[index])
2949
2950 #define NEIGH_SYSCTL_ENTRY(attr, data_attr, name, mval, proc) \
2951         [NEIGH_VAR_ ## attr] = { \
2952                 .procname       = name, \
2953                 .data           = NEIGH_PARMS_DATA_OFFSET(NEIGH_VAR_ ## data_attr), \
2954                 .maxlen         = sizeof(int), \
2955                 .mode           = mval, \
2956                 .proc_handler   = proc, \
2957         }
2958
2959 #define NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(attr, name) \
2960         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_zero_intmax)
2961
2962 #define NEIGH_SYSCTL_JIFFIES_ENTRY(attr, name) \
2963         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_jiffies)
2964
2965 #define NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(attr, name) \
2966         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_userhz_jiffies)
2967
2968 #define NEIGH_SYSCTL_MS_JIFFIES_ENTRY(attr, name) \
2969         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_ms_jiffies)
2970
2971 #define NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(attr, data_attr, name) \
2972         NEIGH_SYSCTL_ENTRY(attr, data_attr, name, 0644, neigh_proc_dointvec_ms_jiffies)
2973
2974 #define NEIGH_SYSCTL_UNRES_QLEN_REUSED_ENTRY(attr, data_attr, name) \
2975         NEIGH_SYSCTL_ENTRY(attr, data_attr, name, 0644, neigh_proc_dointvec_unres_qlen)
2976
2977 static struct neigh_sysctl_table {
2978         struct ctl_table_header *sysctl_header;
2979         struct ctl_table neigh_vars[NEIGH_VAR_MAX + 1];
2980 } neigh_sysctl_template __read_mostly = {
2981         .neigh_vars = {
2982                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(MCAST_PROBES, "mcast_solicit"),
2983                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(UCAST_PROBES, "ucast_solicit"),
2984                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(APP_PROBES, "app_solicit"),
2985                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(RETRANS_TIME, "retrans_time"),
2986                 NEIGH_SYSCTL_JIFFIES_ENTRY(BASE_REACHABLE_TIME, "base_reachable_time"),
2987                 NEIGH_SYSCTL_JIFFIES_ENTRY(DELAY_PROBE_TIME, "delay_first_probe_time"),
2988                 NEIGH_SYSCTL_JIFFIES_ENTRY(GC_STALETIME, "gc_stale_time"),
2989                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(QUEUE_LEN_BYTES, "unres_qlen_bytes"),
2990                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(PROXY_QLEN, "proxy_qlen"),
2991                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(ANYCAST_DELAY, "anycast_delay"),
2992                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(PROXY_DELAY, "proxy_delay"),
2993                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(LOCKTIME, "locktime"),
2994                 NEIGH_SYSCTL_UNRES_QLEN_REUSED_ENTRY(QUEUE_LEN, QUEUE_LEN_BYTES, "unres_qlen"),
2995                 NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(RETRANS_TIME_MS, RETRANS_TIME, "retrans_time_ms"),
2996                 NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(BASE_REACHABLE_TIME_MS, BASE_REACHABLE_TIME, "base_reachable_time_ms"),
2997                 [NEIGH_VAR_GC_INTERVAL] = {
2998                         .procname       = "gc_interval",
2999                         .maxlen         = sizeof(int),
3000                         .mode           = 0644,
3001                         .proc_handler   = proc_dointvec_jiffies,
3002                 },
3003                 [NEIGH_VAR_GC_THRESH1] = {
3004                         .procname       = "gc_thresh1",
3005                         .maxlen         = sizeof(int),
3006                         .mode           = 0644,
3007                         .extra1         = &zero,
3008                         .extra2         = &int_max,
3009                         .proc_handler   = proc_dointvec_minmax,
3010                 },
3011                 [NEIGH_VAR_GC_THRESH2] = {
3012                         .procname       = "gc_thresh2",
3013                         .maxlen         = sizeof(int),
3014                         .mode           = 0644,
3015                         .extra1         = &zero,
3016                         .extra2         = &int_max,
3017                         .proc_handler   = proc_dointvec_minmax,
3018                 },
3019                 [NEIGH_VAR_GC_THRESH3] = {
3020                         .procname       = "gc_thresh3",
3021                         .maxlen         = sizeof(int),
3022                         .mode           = 0644,
3023                         .extra1         = &zero,
3024                         .extra2         = &int_max,
3025                         .proc_handler   = proc_dointvec_minmax,
3026                 },
3027                 {},
3028         },
3029 };
3030
3031 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
3032                           proc_handler *handler)
3033 {
3034         int i;
3035         struct neigh_sysctl_table *t;
3036         const char *dev_name_source;
3037         char neigh_path[ sizeof("net//neigh/") + IFNAMSIZ + IFNAMSIZ ];
3038         char *p_name;
3039
3040         t = kmemdup(&neigh_sysctl_template, sizeof(*t), GFP_KERNEL);
3041         if (!t)
3042                 goto err;
3043
3044         for (i = 0; i < ARRAY_SIZE(t->neigh_vars); i++) {
3045                 t->neigh_vars[i].data += (long) p;
3046                 t->neigh_vars[i].extra1 = dev;
3047                 t->neigh_vars[i].extra2 = p;
3048         }
3049
3050         if (dev) {
3051                 dev_name_source = dev->name;
3052                 /* Terminate the table early */
3053                 memset(&t->neigh_vars[NEIGH_VAR_GC_INTERVAL], 0,
3054                        sizeof(t->neigh_vars[NEIGH_VAR_GC_INTERVAL]));
3055         } else {
3056                 dev_name_source = "default";
3057                 t->neigh_vars[NEIGH_VAR_GC_INTERVAL].data = (int *)(p + 1);
3058                 t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = (int *)(p + 1) + 1;
3059                 t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = (int *)(p + 1) + 2;
3060                 t->neigh_vars[NEIGH_VAR_GC_THRESH3].data = (int *)(p + 1) + 3;
3061         }
3062
3063         if (handler) {
3064                 /* RetransTime */
3065                 t->neigh_vars[NEIGH_VAR_RETRANS_TIME].proc_handler = handler;
3066                 /* ReachableTime */
3067                 t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].proc_handler = handler;
3068                 /* RetransTime (in milliseconds)*/
3069                 t->neigh_vars[NEIGH_VAR_RETRANS_TIME_MS].proc_handler = handler;
3070                 /* ReachableTime (in milliseconds) */
3071                 t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].proc_handler = handler;
3072         }
3073
3074         /* Don't export sysctls to unprivileged users */
3075         if (neigh_parms_net(p)->user_ns != &init_user_ns)
3076                 t->neigh_vars[0].procname = NULL;
3077
3078         switch (neigh_parms_family(p)) {
3079         case AF_INET:
3080               p_name = "ipv4";
3081               break;
3082         case AF_INET6:
3083               p_name = "ipv6";
3084               break;
3085         default:
3086               BUG();
3087         }
3088
3089         snprintf(neigh_path, sizeof(neigh_path), "net/%s/neigh/%s",
3090                 p_name, dev_name_source);
3091         t->sysctl_header =
3092                 register_net_sysctl(neigh_parms_net(p), neigh_path, t->neigh_vars);
3093         if (!t->sysctl_header)
3094                 goto free;
3095
3096         p->sysctl_table = t;
3097         return 0;
3098
3099 free:
3100         kfree(t);
3101 err:
3102         return -ENOBUFS;
3103 }
3104 EXPORT_SYMBOL(neigh_sysctl_register);
3105
3106 void neigh_sysctl_unregister(struct neigh_parms *p)
3107 {
3108         if (p->sysctl_table) {
3109                 struct neigh_sysctl_table *t = p->sysctl_table;
3110                 p->sysctl_table = NULL;
3111                 unregister_net_sysctl_table(t->sysctl_header);
3112                 kfree(t);
3113         }
3114 }
3115 EXPORT_SYMBOL(neigh_sysctl_unregister);
3116
3117 #endif  /* CONFIG_SYSCTL */
3118
3119 static int __init neigh_init(void)
3120 {
3121         rtnl_register(PF_UNSPEC, RTM_NEWNEIGH, neigh_add, NULL, NULL);
3122         rtnl_register(PF_UNSPEC, RTM_DELNEIGH, neigh_delete, NULL, NULL);
3123         rtnl_register(PF_UNSPEC, RTM_GETNEIGH, NULL, neigh_dump_info, NULL);
3124
3125         rtnl_register(PF_UNSPEC, RTM_GETNEIGHTBL, NULL, neightbl_dump_info,
3126                       NULL);
3127         rtnl_register(PF_UNSPEC, RTM_SETNEIGHTBL, neightbl_set, NULL, NULL);
3128
3129         return 0;
3130 }
3131
3132 subsys_initcall(neigh_init);
3133