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 ? (prandom_u32() % 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         /*
 770          *      periodically recompute ReachableTime from random function
 771          */
 772
 773         if (time_after(jiffies, tbl->last_rand + 300 * HZ)) {
 774                 struct neigh_parms *p;
 775                 tbl->last_rand = jiffies;
 776                 for (p = &tbl->parms; p; p = p->next)
 777                         p->reachable_time =
 778                                 neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
 779         }
 780
 781         if (atomic_read(&tbl->entries) < tbl->gc_thresh1)
 782                 goto out;
 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         queue_delayed_work(system_power_efficient_wq, &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         int max_probes = NEIGH_VAR(p, UCAST_PROBES) + NEIGH_VAR(p, APP_PROBES);
 840         if (!(n->nud_state & NUD_PROBE))
 841                 max_probes += NEIGH_VAR(p, MCAST_PROBES);
 842         return max_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                 goto out;
 949         }
 950
 951         if (neigh->nud_state & NUD_IN_TIMER) {
 952                 if (time_before(next, jiffies + HZ/2))
 953                         next = jiffies + HZ/2;
 954                 if (!mod_timer(&neigh->timer, next))
 955                         neigh_hold(neigh);
 956         }
 957         if (neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) {
 958                 neigh_probe(neigh);
 959         } else {
 960 out:
 961                 write_unlock(&neigh->lock);
 962         }
 963
 964         if (notify)
 965                 neigh_update_notify(neigh);
 966
 967         neigh_release(neigh);
 968 }
 969
 970 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 971 {
 972         int rc;
 973         bool immediate_probe = false;
 974
 975         write_lock_bh(&neigh->lock);
 976
 977         rc = 0;
 978         if (neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE))
 979                 goto out_unlock_bh;
 980
 981         if (!(neigh->nud_state & (NUD_STALE | NUD_INCOMPLETE))) {
 982                 if (NEIGH_VAR(neigh->parms, MCAST_PROBES) +
 983                     NEIGH_VAR(neigh->parms, APP_PROBES)) {
 984                         unsigned long next, now = jiffies;
 985
 986                         atomic_set(&neigh->probes,
 987                                    NEIGH_VAR(neigh->parms, UCAST_PROBES));
 988                         neigh->nud_state     = NUD_INCOMPLETE;
 989                         neigh->updated = now;
 990                         next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),
 991                                          HZ/2);
 992                         neigh_add_timer(neigh, next);
 993                         immediate_probe = true;
 994                 } else {
 995                         neigh->nud_state = NUD_FAILED;
 996                         neigh->updated = jiffies;
 997                         write_unlock_bh(&neigh->lock);
 998
 999                         kfree_skb(skb);
1000                         return 1;
1001                 }
1002         } else if (neigh->nud_state & NUD_STALE) {
1003                 neigh_dbg(2, "neigh %p is delayed\n", neigh);
1004                 neigh->nud_state = NUD_DELAY;
1005                 neigh->updated = jiffies;
1006                 neigh_add_timer(neigh, jiffies +
1007                                 NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME));
1008         }
1009
1010         if (neigh->nud_state == NUD_INCOMPLETE) {
1011                 if (skb) {
1012                         while (neigh->arp_queue_len_bytes + skb->truesize >
1013                                NEIGH_VAR(neigh->parms, QUEUE_LEN_BYTES)) {
1014                                 struct sk_buff *buff;
1015
1016                                 buff = __skb_dequeue(&neigh->arp_queue);
1017                                 if (!buff)
1018                                         break;
1019                                 neigh->arp_queue_len_bytes -= buff->truesize;
1020                                 kfree_skb(buff);
1021                                 NEIGH_CACHE_STAT_INC(neigh->tbl, unres_discards);
1022                         }
1023                         skb_dst_force(skb);
1024                         __skb_queue_tail(&neigh->arp_queue, skb);
1025                         neigh->arp_queue_len_bytes += skb->truesize;
1026                 }
1027                 rc = 1;
1028         }
1029 out_unlock_bh:
1030         if (immediate_probe)
1031                 neigh_probe(neigh);
1032         else
1033                 write_unlock(&neigh->lock);
1034         local_bh_enable();
1035         return rc;
1036 }
1037 EXPORT_SYMBOL(__neigh_event_send);
1038
1039 static void neigh_update_hhs(struct neighbour *neigh)
1040 {
1041         struct hh_cache *hh;
1042         void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *)
1043                 = NULL;
1044
1045         if (neigh->dev->header_ops)
1046                 update = neigh->dev->header_ops->cache_update;
1047
1048         if (update) {
1049                 hh = &neigh->hh;
1050                 if (hh->hh_len) {
1051                         write_seqlock_bh(&hh->hh_lock);
1052                         update(hh, neigh->dev, neigh->ha);
1053                         write_sequnlock_bh(&hh->hh_lock);
1054                 }
1055         }
1056 }
1057
1058
1059
1060 /* Generic update routine.
1061    -- lladdr is new lladdr or NULL, if it is not supplied.
1062    -- new    is new state.
1063    -- flags
1064         NEIGH_UPDATE_F_OVERRIDE allows to override existing lladdr,
1065                                 if it is different.
1066         NEIGH_UPDATE_F_WEAK_OVERRIDE will suspect existing "connected"
1067                                 lladdr instead of overriding it
1068                                 if it is different.
1069                                 It also allows to retain current state
1070                                 if lladdr is unchanged.
1071         NEIGH_UPDATE_F_ADMIN    means that the change is administrative.
1072
1073         NEIGH_UPDATE_F_OVERRIDE_ISROUTER allows to override existing
1074                                 NTF_ROUTER flag.
1075         NEIGH_UPDATE_F_ISROUTER indicates if the neighbour is known as
1076                                 a router.
1077
1078    Caller MUST hold reference count on the entry.
1079  */
1080
1081 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
1082                  u32 flags)
1083 {
1084         u8 old;
1085         int err;
1086         int notify = 0;
1087         struct net_device *dev;
1088         int update_isrouter = 0;
1089
1090         write_lock_bh(&neigh->lock);
1091
1092         dev    = neigh->dev;
1093         old    = neigh->nud_state;
1094         err    = -EPERM;
1095
1096         if (!(flags & NEIGH_UPDATE_F_ADMIN) &&
1097             (old & (NUD_NOARP | NUD_PERMANENT)))
1098                 goto out;
1099
1100         if (!(new & NUD_VALID)) {
1101                 neigh_del_timer(neigh);
1102                 if (old & NUD_CONNECTED)
1103                         neigh_suspect(neigh);
1104                 neigh->nud_state = new;
1105                 err = 0;
1106                 notify = old & NUD_VALID;
1107                 if ((old & (NUD_INCOMPLETE | NUD_PROBE)) &&
1108                     (new & NUD_FAILED)) {
1109                         neigh_invalidate(neigh);
1110                         notify = 1;
1111                 }
1112                 goto out;
1113         }
1114
1115         /* Compare new lladdr with cached one */
1116         if (!dev->addr_len) {
1117                 /* First case: device needs no address. */
1118                 lladdr = neigh->ha;
1119         } else if (lladdr) {
1120                 /* The second case: if something is already cached
1121                    and a new address is proposed:
1122                    - compare new & old
1123                    - if they are different, check override flag
1124                  */
1125                 if ((old & NUD_VALID) &&
1126                     !memcmp(lladdr, neigh->ha, dev->addr_len))
1127                         lladdr = neigh->ha;
1128         } else {
1129                 /* No address is supplied; if we know something,
1130                    use it, otherwise discard the request.
1131                  */
1132                 err = -EINVAL;
1133                 if (!(old & NUD_VALID))
1134                         goto out;
1135                 lladdr = neigh->ha;
1136         }
1137
1138         if (new & NUD_CONNECTED)
1139                 neigh->confirmed = jiffies;
1140         neigh->updated = jiffies;
1141
1142         /* If entry was valid and address is not changed,
1143            do not change entry state, if new one is STALE.
1144          */
1145         err = 0;
1146         update_isrouter = flags & NEIGH_UPDATE_F_OVERRIDE_ISROUTER;
1147         if (old & NUD_VALID) {
1148                 if (lladdr != neigh->ha && !(flags & NEIGH_UPDATE_F_OVERRIDE)) {
1149                         update_isrouter = 0;
1150                         if ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) &&
1151                             (old & NUD_CONNECTED)) {
1152                                 lladdr = neigh->ha;
1153                                 new = NUD_STALE;
1154                         } else
1155                                 goto out;
1156                 } else {
1157                         if (lladdr == neigh->ha && new == NUD_STALE &&
1158                             ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) ||
1159                              (old & NUD_CONNECTED))
1160                             )
1161                                 new = old;
1162                 }
1163         }
1164
1165         if (new != old) {
1166                 neigh_del_timer(neigh);
1167                 if (new & NUD_IN_TIMER)
1168                         neigh_add_timer(neigh, (jiffies +
1169                                                 ((new & NUD_REACHABLE) ?
1170                                                  neigh->parms->reachable_time :
1171                                                  0)));
1172                 neigh->nud_state = new;
1173                 notify = 1;
1174         }
1175
1176         if (lladdr != neigh->ha) {
1177                 write_seqlock(&neigh->ha_lock);
1178                 memcpy(&neigh->ha, lladdr, dev->addr_len);
1179                 write_sequnlock(&neigh->ha_lock);
1180                 neigh_update_hhs(neigh);
1181                 if (!(new & NUD_CONNECTED))
1182                         neigh->confirmed = jiffies -
1183                                       (NEIGH_VAR(neigh->parms, BASE_REACHABLE_TIME) << 1);
1184                 notify = 1;
1185         }
1186         if (new == old)
1187                 goto out;
1188         if (new & NUD_CONNECTED)
1189                 neigh_connect(neigh);
1190         else
1191                 neigh_suspect(neigh);
1192         if (!(old & NUD_VALID)) {
1193                 struct sk_buff *skb;
1194
1195                 /* Again: avoid dead loop if something went wrong */
1196
1197                 while (neigh->nud_state & NUD_VALID &&
1198                        (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
1199                         struct dst_entry *dst = skb_dst(skb);
1200                         struct neighbour *n2, *n1 = neigh;
1201                         write_unlock_bh(&neigh->lock);
1202
1203                         rcu_read_lock();
1204
1205                         /* Why not just use 'neigh' as-is?  The problem is that
1206                          * things such as shaper, eql, and sch_teql can end up
1207                          * using alternative, different, neigh objects to output
1208                          * the packet in the output path.  So what we need to do
1209                          * here is re-lookup the top-level neigh in the path so
1210                          * we can reinject the packet there.
1211                          */
1212                         n2 = NULL;
1213                         if (dst) {
1214                                 n2 = dst_neigh_lookup_skb(dst, skb);
1215                                 if (n2)
1216                                         n1 = n2;
1217                         }
1218                         n1->output(n1, skb);
1219                         if (n2)
1220                                 neigh_release(n2);
1221                         rcu_read_unlock();
1222
1223                         write_lock_bh(&neigh->lock);
1224                 }
1225                 __skb_queue_purge(&neigh->arp_queue);
1226                 neigh->arp_queue_len_bytes = 0;
1227         }
1228 out:
1229         if (update_isrouter) {
1230                 neigh->flags = (flags & NEIGH_UPDATE_F_ISROUTER) ?
1231                         (neigh->flags | NTF_ROUTER) :
1232                         (neigh->flags & ~NTF_ROUTER);
1233         }
1234         write_unlock_bh(&neigh->lock);
1235
1236         if (notify)
1237                 neigh_update_notify(neigh);
1238
1239         return err;
1240 }
1241 EXPORT_SYMBOL(neigh_update);
1242
1243 /* Update the neigh to listen temporarily for probe responses, even if it is
1244  * in a NUD_FAILED state. The caller has to hold neigh->lock for writing.
1245  */
1246 void __neigh_set_probe_once(struct neighbour *neigh)
1247 {
1248         neigh->updated = jiffies;
1249         if (!(neigh->nud_state & NUD_FAILED))
1250                 return;
1251         neigh->nud_state = NUD_INCOMPLETE;
1252         atomic_set(&neigh->probes, neigh_max_probes(neigh));
1253         neigh_add_timer(neigh,
1254                         jiffies + NEIGH_VAR(neigh->parms, RETRANS_TIME));
1255 }
1256 EXPORT_SYMBOL(__neigh_set_probe_once);
1257
1258 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
1259                                  u8 *lladdr, void *saddr,
1260                                  struct net_device *dev)
1261 {
1262         struct neighbour *neigh = __neigh_lookup(tbl, saddr, dev,
1263                                                  lladdr || !dev->addr_len);
1264         if (neigh)
1265                 neigh_update(neigh, lladdr, NUD_STALE,
1266                              NEIGH_UPDATE_F_OVERRIDE);
1267         return neigh;
1268 }
1269 EXPORT_SYMBOL(neigh_event_ns);
1270
1271 /* called with read_lock_bh(&n->lock); */
1272 static void neigh_hh_init(struct neighbour *n, struct dst_entry *dst)
1273 {
1274         struct net_device *dev = dst->dev;
1275         __be16 prot = dst->ops->protocol;
1276         struct hh_cache *hh = &n->hh;
1277
1278         write_lock_bh(&n->lock);
1279
1280         /* Only one thread can come in here and initialize the
1281          * hh_cache entry.
1282          */
1283         if (!hh->hh_len)
1284                 dev->header_ops->cache(n, hh, prot);
1285
1286         write_unlock_bh(&n->lock);
1287 }
1288
1289 /* This function can be used in contexts, where only old dev_queue_xmit
1290  * worked, f.e. if you want to override normal output path (eql, shaper),
1291  * but resolution is not made yet.
1292  */
1293
1294 int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb)
1295 {
1296         struct net_device *dev = skb->dev;
1297
1298         __skb_pull(skb, skb_network_offset(skb));
1299
1300         if (dev_hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
1301                             skb->len) < 0 &&
1302             dev_rebuild_header(skb))
1303                 return 0;
1304
1305         return dev_queue_xmit(skb);
1306 }
1307 EXPORT_SYMBOL(neigh_compat_output);
1308
1309 /* Slow and careful. */
1310
1311 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb)
1312 {
1313         struct dst_entry *dst = skb_dst(skb);
1314         int rc = 0;
1315
1316         if (!dst)
1317                 goto discard;
1318
1319         if (!neigh_event_send(neigh, skb)) {
1320                 int err;
1321                 struct net_device *dev = neigh->dev;
1322                 unsigned int seq;
1323
1324                 if (dev->header_ops->cache && !neigh->hh.hh_len)
1325                         neigh_hh_init(neigh, dst);
1326
1327                 do {
1328                         __skb_pull(skb, skb_network_offset(skb));
1329                         seq = read_seqbegin(&neigh->ha_lock);
1330                         err = dev_hard_header(skb, dev, ntohs(skb->protocol),
1331                                               neigh->ha, NULL, skb->len);
1332                 } while (read_seqretry(&neigh->ha_lock, seq));
1333
1334                 if (err >= 0)
1335                         rc = dev_queue_xmit(skb);
1336                 else
1337                         goto out_kfree_skb;
1338         }
1339 out:
1340         return rc;
1341 discard:
1342         neigh_dbg(1, "%s: dst=%p neigh=%p\n", __func__, dst, neigh);
1343 out_kfree_skb:
1344         rc = -EINVAL;
1345         kfree_skb(skb);
1346         goto out;
1347 }
1348 EXPORT_SYMBOL(neigh_resolve_output);
1349
1350 /* As fast as possible without hh cache */
1351
1352 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb)
1353 {
1354         struct net_device *dev = neigh->dev;
1355         unsigned int seq;
1356         int err;
1357
1358         do {
1359                 __skb_pull(skb, skb_network_offset(skb));
1360                 seq = read_seqbegin(&neigh->ha_lock);
1361                 err = dev_hard_header(skb, dev, ntohs(skb->protocol),
1362                                       neigh->ha, NULL, skb->len);
1363         } while (read_seqretry(&neigh->ha_lock, seq));
1364
1365         if (err >= 0)
1366                 err = dev_queue_xmit(skb);
1367         else {
1368                 err = -EINVAL;
1369                 kfree_skb(skb);
1370         }
1371         return err;
1372 }
1373 EXPORT_SYMBOL(neigh_connected_output);
1374
1375 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb)
1376 {
1377         return dev_queue_xmit(skb);
1378 }
1379 EXPORT_SYMBOL(neigh_direct_output);
1380
1381 static void neigh_proxy_process(unsigned long arg)
1382 {
1383         struct neigh_table *tbl = (struct neigh_table *)arg;
1384         long sched_next = 0;
1385         unsigned long now = jiffies;
1386         struct sk_buff *skb, *n;
1387
1388         spin_lock(&tbl->proxy_queue.lock);
1389
1390         skb_queue_walk_safe(&tbl->proxy_queue, skb, n) {
1391                 long tdif = NEIGH_CB(skb)->sched_next - now;
1392
1393                 if (tdif <= 0) {
1394                         struct net_device *dev = skb->dev;
1395
1396                         __skb_unlink(skb, &tbl->proxy_queue);
1397                         if (tbl->proxy_redo && netif_running(dev)) {
1398                                 rcu_read_lock();
1399                                 tbl->proxy_redo(skb);
1400                                 rcu_read_unlock();
1401                         } else {
1402                                 kfree_skb(skb);
1403                         }
1404
1405                         dev_put(dev);
1406                 } else if (!sched_next || tdif < sched_next)
1407                         sched_next = tdif;
1408         }
1409         del_timer(&tbl->proxy_timer);
1410         if (sched_next)
1411                 mod_timer(&tbl->proxy_timer, jiffies + sched_next);
1412         spin_unlock(&tbl->proxy_queue.lock);
1413 }
1414
1415 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
1416                     struct sk_buff *skb)
1417 {
1418         unsigned long now = jiffies;
1419
1420         unsigned long sched_next = now + (prandom_u32() %
1421                                           NEIGH_VAR(p, PROXY_DELAY));
1422
1423         if (tbl->proxy_queue.qlen > NEIGH_VAR(p, PROXY_QLEN)) {
1424                 kfree_skb(skb);
1425                 return;
1426         }
1427
1428         NEIGH_CB(skb)->sched_next = sched_next;
1429         NEIGH_CB(skb)->flags |= LOCALLY_ENQUEUED;
1430
1431         spin_lock(&tbl->proxy_queue.lock);
1432         if (del_timer(&tbl->proxy_timer)) {
1433                 if (time_before(tbl->proxy_timer.expires, sched_next))
1434                         sched_next = tbl->proxy_timer.expires;
1435         }
1436         skb_dst_drop(skb);
1437         dev_hold(skb->dev);
1438         __skb_queue_tail(&tbl->proxy_queue, skb);
1439         mod_timer(&tbl->proxy_timer, sched_next);
1440         spin_unlock(&tbl->proxy_queue.lock);
1441 }
1442 EXPORT_SYMBOL(pneigh_enqueue);
1443
1444 static inline struct neigh_parms *lookup_neigh_parms(struct neigh_table *tbl,
1445                                                       struct net *net, int ifindex)
1446 {
1447         struct neigh_parms *p;
1448
1449         for (p = &tbl->parms; p; p = p->next) {
1450                 if ((p->dev && p->dev->ifindex == ifindex && net_eq(neigh_parms_net(p), net)) ||
1451                     (!p->dev && !ifindex && net_eq(net, &init_net)))
1452                         return p;
1453         }
1454
1455         return NULL;
1456 }
1457
1458 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
1459                                       struct neigh_table *tbl)
1460 {
1461         struct neigh_parms *p;
1462         struct net *net = dev_net(dev);
1463         const struct net_device_ops *ops = dev->netdev_ops;
1464
1465         p = kmemdup(&tbl->parms, sizeof(*p), GFP_KERNEL);
1466         if (p) {
1467                 p->tbl            = tbl;
1468                 atomic_set(&p->refcnt, 1);
1469                 p->reachable_time =
1470                                 neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
1471                 dev_hold(dev);
1472                 p->dev = dev;
1473                 write_pnet(&p->net, hold_net(net));
1474                 p->sysctl_table = NULL;
1475
1476                 if (ops->ndo_neigh_setup && ops->ndo_neigh_setup(dev, p)) {
1477                         release_net(net);
1478                         dev_put(dev);
1479                         kfree(p);
1480                         return NULL;
1481                 }
1482
1483                 write_lock_bh(&tbl->lock);
1484                 p->next         = tbl->parms.next;
1485                 tbl->parms.next = p;
1486                 write_unlock_bh(&tbl->lock);
1487
1488                 neigh_parms_data_state_cleanall(p);
1489         }
1490         return p;
1491 }
1492 EXPORT_SYMBOL(neigh_parms_alloc);
1493
1494 static void neigh_rcu_free_parms(struct rcu_head *head)
1495 {
1496         struct neigh_parms *parms =
1497                 container_of(head, struct neigh_parms, rcu_head);
1498
1499         neigh_parms_put(parms);
1500 }
1501
1502 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
1503 {
1504         struct neigh_parms **p;
1505
1506         if (!parms || parms == &tbl->parms)
1507                 return;
1508         write_lock_bh(&tbl->lock);
1509         for (p = &tbl->parms.next; *p; p = &(*p)->next) {
1510                 if (*p == parms) {
1511                         *p = parms->next;
1512                         parms->dead = 1;
1513                         write_unlock_bh(&tbl->lock);
1514                         if (parms->dev)
1515                                 dev_put(parms->dev);
1516                         call_rcu(&parms->rcu_head, neigh_rcu_free_parms);
1517                         return;
1518                 }
1519         }
1520         write_unlock_bh(&tbl->lock);
1521         neigh_dbg(1, "%s: not found\n", __func__);
1522 }
1523 EXPORT_SYMBOL(neigh_parms_release);
1524
1525 static void neigh_parms_destroy(struct neigh_parms *parms)
1526 {
1527         release_net(neigh_parms_net(parms));
1528         kfree(parms);
1529 }
1530
1531 static struct lock_class_key neigh_table_proxy_queue_class;
1532
1533 static void neigh_table_init_no_netlink(struct neigh_table *tbl)
1534 {
1535         unsigned long now = jiffies;
1536         unsigned long phsize;
1537
1538         write_pnet(&tbl->parms.net, &init_net);
1539         atomic_set(&tbl->parms.refcnt, 1);
1540         tbl->parms.reachable_time =
1541                           neigh_rand_reach_time(NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME));
1542
1543         tbl->stats = alloc_percpu(struct neigh_statistics);
1544         if (!tbl->stats)
1545                 panic("cannot create neighbour cache statistics");
1546
1547 #ifdef CONFIG_PROC_FS
1548         if (!proc_create_data(tbl->id, 0, init_net.proc_net_stat,
1549                               &neigh_stat_seq_fops, tbl))
1550                 panic("cannot create neighbour proc dir entry");
1551 #endif
1552
1553         RCU_INIT_POINTER(tbl->nht, neigh_hash_alloc(3));
1554
1555         phsize = (PNEIGH_HASHMASK + 1) * sizeof(struct pneigh_entry *);
1556         tbl->phash_buckets = kzalloc(phsize, GFP_KERNEL);
1557
1558         if (!tbl->nht || !tbl->phash_buckets)
1559                 panic("cannot allocate neighbour cache hashes");
1560
1561         if (!tbl->entry_size)
1562                 tbl->entry_size = ALIGN(offsetof(struct neighbour, primary_key) +
1563                                         tbl->key_len, NEIGH_PRIV_ALIGN);
1564         else
1565                 WARN_ON(tbl->entry_size % NEIGH_PRIV_ALIGN);
1566
1567         rwlock_init(&tbl->lock);
1568         INIT_DEFERRABLE_WORK(&tbl->gc_work, neigh_periodic_work);
1569         queue_delayed_work(system_power_efficient_wq, &tbl->gc_work,
1570                         tbl->parms.reachable_time);
1571         setup_timer(&tbl->proxy_timer, neigh_proxy_process, (unsigned long)tbl);
1572         skb_queue_head_init_class(&tbl->proxy_queue,
1573                         &neigh_table_proxy_queue_class);
1574
1575         tbl->last_flush = now;
1576         tbl->last_rand  = now + tbl->parms.reachable_time * 20;
1577 }
1578
1579 void neigh_table_init(struct neigh_table *tbl)
1580 {
1581         struct neigh_table *tmp;
1582
1583         neigh_table_init_no_netlink(tbl);
1584         write_lock(&neigh_tbl_lock);
1585         for (tmp = neigh_tables; tmp; tmp = tmp->next) {
1586                 if (tmp->family == tbl->family)
1587                         break;
1588         }
1589         tbl->next       = neigh_tables;
1590         neigh_tables    = tbl;
1591         write_unlock(&neigh_tbl_lock);
1592
1593         if (unlikely(tmp)) {
1594                 pr_err("Registering multiple tables for family %d\n",
1595                        tbl->family);
1596                 dump_stack();
1597         }
1598 }
1599 EXPORT_SYMBOL(neigh_table_init);
1600
1601 int neigh_table_clear(struct neigh_table *tbl)
1602 {
1603         struct neigh_table **tp;
1604
1605         /* It is not clean... Fix it to unload IPv6 module safely */
1606         cancel_delayed_work_sync(&tbl->gc_work);
1607         del_timer_sync(&tbl->proxy_timer);
1608         pneigh_queue_purge(&tbl->proxy_queue);
1609         neigh_ifdown(tbl, NULL);
1610         if (atomic_read(&tbl->entries))
1611                 pr_crit("neighbour leakage\n");
1612         write_lock(&neigh_tbl_lock);
1613         for (tp = &neigh_tables; *tp; tp = &(*tp)->next) {
1614                 if (*tp == tbl) {
1615                         *tp = tbl->next;
1616                         break;
1617                 }
1618         }
1619         write_unlock(&neigh_tbl_lock);
1620
1621         call_rcu(&rcu_dereference_protected(tbl->nht, 1)->rcu,
1622                  neigh_hash_free_rcu);
1623         tbl->nht = NULL;
1624
1625         kfree(tbl->phash_buckets);
1626         tbl->phash_buckets = NULL;
1627
1628         remove_proc_entry(tbl->id, init_net.proc_net_stat);
1629
1630         free_percpu(tbl->stats);
1631         tbl->stats = NULL;
1632
1633         return 0;
1634 }
1635 EXPORT_SYMBOL(neigh_table_clear);
1636
1637 static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh)
1638 {
1639         struct net *net = sock_net(skb->sk);
1640         struct ndmsg *ndm;
1641         struct nlattr *dst_attr;
1642         struct neigh_table *tbl;
1643         struct net_device *dev = NULL;
1644         int err = -EINVAL;
1645
1646         ASSERT_RTNL();
1647         if (nlmsg_len(nlh) < sizeof(*ndm))
1648                 goto out;
1649
1650         dst_attr = nlmsg_find_attr(nlh, sizeof(*ndm), NDA_DST);
1651         if (dst_attr == NULL)
1652                 goto out;
1653
1654         ndm = nlmsg_data(nlh);
1655         if (ndm->ndm_ifindex) {
1656                 dev = __dev_get_by_index(net, ndm->ndm_ifindex);
1657                 if (dev == NULL) {
1658                         err = -ENODEV;
1659                         goto out;
1660                 }
1661         }
1662
1663         read_lock(&neigh_tbl_lock);
1664         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1665                 struct neighbour *neigh;
1666
1667                 if (tbl->family != ndm->ndm_family)
1668                         continue;
1669                 read_unlock(&neigh_tbl_lock);
1670
1671                 if (nla_len(dst_attr) < tbl->key_len)
1672                         goto out;
1673
1674                 if (ndm->ndm_flags & NTF_PROXY) {
1675                         err = pneigh_delete(tbl, net, nla_data(dst_attr), dev);
1676                         goto out;
1677                 }
1678
1679                 if (dev == NULL)
1680                         goto out;
1681
1682                 neigh = neigh_lookup(tbl, nla_data(dst_attr), dev);
1683                 if (neigh == NULL) {
1684                         err = -ENOENT;
1685                         goto out;
1686                 }
1687
1688                 err = neigh_update(neigh, NULL, NUD_FAILED,
1689                                    NEIGH_UPDATE_F_OVERRIDE |
1690                                    NEIGH_UPDATE_F_ADMIN);
1691                 neigh_release(neigh);
1692                 goto out;
1693         }
1694         read_unlock(&neigh_tbl_lock);
1695         err = -EAFNOSUPPORT;
1696
1697 out:
1698         return err;
1699 }
1700
1701 static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh)
1702 {
1703         struct net *net = sock_net(skb->sk);
1704         struct ndmsg *ndm;
1705         struct nlattr *tb[NDA_MAX+1];
1706         struct neigh_table *tbl;
1707         struct net_device *dev = NULL;
1708         int err;
1709
1710         ASSERT_RTNL();
1711         err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
1712         if (err < 0)
1713                 goto out;
1714
1715         err = -EINVAL;
1716         if (tb[NDA_DST] == NULL)
1717                 goto out;
1718
1719         ndm = nlmsg_data(nlh);
1720         if (ndm->ndm_ifindex) {
1721                 dev = __dev_get_by_index(net, ndm->ndm_ifindex);
1722                 if (dev == NULL) {
1723                         err = -ENODEV;
1724                         goto out;
1725                 }
1726
1727                 if (tb[NDA_LLADDR] && nla_len(tb[NDA_LLADDR]) < dev->addr_len)
1728                         goto out;
1729         }
1730
1731         read_lock(&neigh_tbl_lock);
1732         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1733                 int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE;
1734                 struct neighbour *neigh;
1735                 void *dst, *lladdr;
1736
1737                 if (tbl->family != ndm->ndm_family)
1738                         continue;
1739                 read_unlock(&neigh_tbl_lock);
1740
1741                 if (nla_len(tb[NDA_DST]) < tbl->key_len)
1742                         goto out;
1743                 dst = nla_data(tb[NDA_DST]);
1744                 lladdr = tb[NDA_LLADDR] ? nla_data(tb[NDA_LLADDR]) : NULL;
1745
1746                 if (ndm->ndm_flags & NTF_PROXY) {
1747                         struct pneigh_entry *pn;
1748
1749                         err = -ENOBUFS;
1750                         pn = pneigh_lookup(tbl, net, dst, dev, 1);
1751                         if (pn) {
1752                                 pn->flags = ndm->ndm_flags;
1753                                 err = 0;
1754                         }
1755                         goto out;
1756                 }
1757
1758                 if (dev == NULL)
1759                         goto out;
1760
1761                 neigh = neigh_lookup(tbl, dst, dev);
1762                 if (neigh == NULL) {
1763                         if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
1764                                 err = -ENOENT;
1765                                 goto out;
1766                         }
1767
1768                         neigh = __neigh_lookup_errno(tbl, dst, dev);
1769                         if (IS_ERR(neigh)) {
1770                                 err = PTR_ERR(neigh);
1771                                 goto out;
1772                         }
1773                 } else {
1774                         if (nlh->nlmsg_flags & NLM_F_EXCL) {
1775                                 err = -EEXIST;
1776                                 neigh_release(neigh);
1777                                 goto out;
1778                         }
1779
1780                         if (!(nlh->nlmsg_flags & NLM_F_REPLACE))
1781                                 flags &= ~NEIGH_UPDATE_F_OVERRIDE;
1782                 }
1783
1784                 if (ndm->ndm_flags & NTF_USE) {
1785                         neigh_event_send(neigh, NULL);
1786                         err = 0;
1787                 } else
1788                         err = neigh_update(neigh, lladdr, ndm->ndm_state, flags);
1789                 neigh_release(neigh);
1790                 goto out;
1791         }
1792
1793         read_unlock(&neigh_tbl_lock);
1794         err = -EAFNOSUPPORT;
1795 out:
1796         return err;
1797 }
1798
1799 static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms)
1800 {
1801         struct nlattr *nest;
1802
1803         nest = nla_nest_start(skb, NDTA_PARMS);
1804         if (nest == NULL)
1805                 return -ENOBUFS;
1806
1807         if ((parms->dev &&
1808              nla_put_u32(skb, NDTPA_IFINDEX, parms->dev->ifindex)) ||
1809             nla_put_u32(skb, NDTPA_REFCNT, atomic_read(&parms->refcnt)) ||
1810             nla_put_u32(skb, NDTPA_QUEUE_LENBYTES,
1811                         NEIGH_VAR(parms, QUEUE_LEN_BYTES)) ||
1812             /* approximative value for deprecated QUEUE_LEN (in packets) */
1813             nla_put_u32(skb, NDTPA_QUEUE_LEN,
1814                         NEIGH_VAR(parms, QUEUE_LEN_BYTES) / SKB_TRUESIZE(ETH_FRAME_LEN)) ||
1815             nla_put_u32(skb, NDTPA_PROXY_QLEN, NEIGH_VAR(parms, PROXY_QLEN)) ||
1816             nla_put_u32(skb, NDTPA_APP_PROBES, NEIGH_VAR(parms, APP_PROBES)) ||
1817             nla_put_u32(skb, NDTPA_UCAST_PROBES,
1818                         NEIGH_VAR(parms, UCAST_PROBES)) ||
1819             nla_put_u32(skb, NDTPA_MCAST_PROBES,
1820                         NEIGH_VAR(parms, MCAST_PROBES)) ||
1821             nla_put_msecs(skb, NDTPA_REACHABLE_TIME, parms->reachable_time) ||
1822             nla_put_msecs(skb, NDTPA_BASE_REACHABLE_TIME,
1823                           NEIGH_VAR(parms, BASE_REACHABLE_TIME)) ||
1824             nla_put_msecs(skb, NDTPA_GC_STALETIME,
1825                           NEIGH_VAR(parms, GC_STALETIME)) ||
1826             nla_put_msecs(skb, NDTPA_DELAY_PROBE_TIME,
1827                           NEIGH_VAR(parms, DELAY_PROBE_TIME)) ||
1828             nla_put_msecs(skb, NDTPA_RETRANS_TIME,
1829                           NEIGH_VAR(parms, RETRANS_TIME)) ||
1830             nla_put_msecs(skb, NDTPA_ANYCAST_DELAY,
1831                           NEIGH_VAR(parms, ANYCAST_DELAY)) ||
1832             nla_put_msecs(skb, NDTPA_PROXY_DELAY,
1833                           NEIGH_VAR(parms, PROXY_DELAY)) ||
1834             nla_put_msecs(skb, NDTPA_LOCKTIME,
1835                           NEIGH_VAR(parms, LOCKTIME)))
1836                 goto nla_put_failure;
1837         return nla_nest_end(skb, nest);
1838
1839 nla_put_failure:
1840         nla_nest_cancel(skb, nest);
1841         return -EMSGSIZE;
1842 }
1843
1844 static int neightbl_fill_info(struct sk_buff *skb, struct neigh_table *tbl,
1845                               u32 pid, u32 seq, int type, int flags)
1846 {
1847         struct nlmsghdr *nlh;
1848         struct ndtmsg *ndtmsg;
1849
1850         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
1851         if (nlh == NULL)
1852                 return -EMSGSIZE;
1853
1854         ndtmsg = nlmsg_data(nlh);
1855
1856         read_lock_bh(&tbl->lock);
1857         ndtmsg->ndtm_family = tbl->family;
1858         ndtmsg->ndtm_pad1   = 0;
1859         ndtmsg->ndtm_pad2   = 0;
1860
1861         if (nla_put_string(skb, NDTA_NAME, tbl->id) ||
1862             nla_put_msecs(skb, NDTA_GC_INTERVAL, tbl->gc_interval) ||
1863             nla_put_u32(skb, NDTA_THRESH1, tbl->gc_thresh1) ||
1864             nla_put_u32(skb, NDTA_THRESH2, tbl->gc_thresh2) ||
1865             nla_put_u32(skb, NDTA_THRESH3, tbl->gc_thresh3))
1866                 goto nla_put_failure;
1867         {
1868                 unsigned long now = jiffies;
1869                 unsigned int flush_delta = now - tbl->last_flush;
1870                 unsigned int rand_delta = now - tbl->last_rand;
1871                 struct neigh_hash_table *nht;
1872                 struct ndt_config ndc = {
1873                         .ndtc_key_len           = tbl->key_len,
1874                         .ndtc_entry_size        = tbl->entry_size,
1875                         .ndtc_entries           = atomic_read(&tbl->entries),
1876                         .ndtc_last_flush        = jiffies_to_msecs(flush_delta),
1877                         .ndtc_last_rand         = jiffies_to_msecs(rand_delta),
1878                         .ndtc_proxy_qlen        = tbl->proxy_queue.qlen,
1879                 };
1880
1881                 rcu_read_lock_bh();
1882                 nht = rcu_dereference_bh(tbl->nht);
1883                 ndc.ndtc_hash_rnd = nht->hash_rnd[0];
1884                 ndc.ndtc_hash_mask = ((1 << nht->hash_shift) - 1);
1885                 rcu_read_unlock_bh();
1886
1887                 if (nla_put(skb, NDTA_CONFIG, sizeof(ndc), &ndc))
1888                         goto nla_put_failure;
1889         }
1890
1891         {
1892                 int cpu;
1893                 struct ndt_stats ndst;
1894
1895                 memset(&ndst, 0, sizeof(ndst));
1896
1897                 for_each_possible_cpu(cpu) {
1898                         struct neigh_statistics *st;
1899
1900                         st = per_cpu_ptr(tbl->stats, cpu);
1901                         ndst.ndts_allocs                += st->allocs;
1902                         ndst.ndts_destroys              += st->destroys;
1903                         ndst.ndts_hash_grows            += st->hash_grows;
1904                         ndst.ndts_res_failed            += st->res_failed;
1905                         ndst.ndts_lookups               += st->lookups;
1906                         ndst.ndts_hits                  += st->hits;
1907                         ndst.ndts_rcv_probes_mcast      += st->rcv_probes_mcast;
1908                         ndst.ndts_rcv_probes_ucast      += st->rcv_probes_ucast;
1909                         ndst.ndts_periodic_gc_runs      += st->periodic_gc_runs;
1910                         ndst.ndts_forced_gc_runs        += st->forced_gc_runs;
1911                 }
1912
1913                 if (nla_put(skb, NDTA_STATS, sizeof(ndst), &ndst))
1914                         goto nla_put_failure;
1915         }
1916
1917         BUG_ON(tbl->parms.dev);
1918         if (neightbl_fill_parms(skb, &tbl->parms) < 0)
1919                 goto nla_put_failure;
1920
1921         read_unlock_bh(&tbl->lock);
1922         return nlmsg_end(skb, nlh);
1923
1924 nla_put_failure:
1925         read_unlock_bh(&tbl->lock);
1926         nlmsg_cancel(skb, nlh);
1927         return -EMSGSIZE;
1928 }
1929
1930 static int neightbl_fill_param_info(struct sk_buff *skb,
1931                                     struct neigh_table *tbl,
1932                                     struct neigh_parms *parms,
1933                                     u32 pid, u32 seq, int type,
1934                                     unsigned int flags)
1935 {
1936         struct ndtmsg *ndtmsg;
1937         struct nlmsghdr *nlh;
1938
1939         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
1940         if (nlh == NULL)
1941                 return -EMSGSIZE;
1942
1943         ndtmsg = nlmsg_data(nlh);
1944
1945         read_lock_bh(&tbl->lock);
1946         ndtmsg->ndtm_family = tbl->family;
1947         ndtmsg->ndtm_pad1   = 0;
1948         ndtmsg->ndtm_pad2   = 0;
1949
1950         if (nla_put_string(skb, NDTA_NAME, tbl->id) < 0 ||
1951             neightbl_fill_parms(skb, parms) < 0)
1952                 goto errout;
1953
1954         read_unlock_bh(&tbl->lock);
1955         return nlmsg_end(skb, nlh);
1956 errout:
1957         read_unlock_bh(&tbl->lock);
1958         nlmsg_cancel(skb, nlh);
1959         return -EMSGSIZE;
1960 }
1961
1962 static const struct nla_policy nl_neightbl_policy[NDTA_MAX+1] = {
1963         [NDTA_NAME]             = { .type = NLA_STRING },
1964         [NDTA_THRESH1]          = { .type = NLA_U32 },
1965         [NDTA_THRESH2]          = { .type = NLA_U32 },
1966         [NDTA_THRESH3]          = { .type = NLA_U32 },
1967         [NDTA_GC_INTERVAL]      = { .type = NLA_U64 },
1968         [NDTA_PARMS]            = { .type = NLA_NESTED },
1969 };
1970
1971 static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
1972         [NDTPA_IFINDEX]                 = { .type = NLA_U32 },
1973         [NDTPA_QUEUE_LEN]               = { .type = NLA_U32 },
1974         [NDTPA_PROXY_QLEN]              = { .type = NLA_U32 },
1975         [NDTPA_APP_PROBES]              = { .type = NLA_U32 },
1976         [NDTPA_UCAST_PROBES]            = { .type = NLA_U32 },
1977         [NDTPA_MCAST_PROBES]            = { .type = NLA_U32 },
1978         [NDTPA_BASE_REACHABLE_TIME]     = { .type = NLA_U64 },
1979         [NDTPA_GC_STALETIME]            = { .type = NLA_U64 },
1980         [NDTPA_DELAY_PROBE_TIME]        = { .type = NLA_U64 },
1981         [NDTPA_RETRANS_TIME]            = { .type = NLA_U64 },
1982         [NDTPA_ANYCAST_DELAY]           = { .type = NLA_U64 },
1983         [NDTPA_PROXY_DELAY]             = { .type = NLA_U64 },
1984         [NDTPA_LOCKTIME]                = { .type = NLA_U64 },
1985 };
1986
1987 static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh)
1988 {
1989         struct net *net = sock_net(skb->sk);
1990         struct neigh_table *tbl;
1991         struct ndtmsg *ndtmsg;
1992         struct nlattr *tb[NDTA_MAX+1];
1993         int err;
1994
1995         err = nlmsg_parse(nlh, sizeof(*ndtmsg), tb, NDTA_MAX,
1996                           nl_neightbl_policy);
1997         if (err < 0)
1998                 goto errout;
1999
2000         if (tb[NDTA_NAME] == NULL) {
2001                 err = -EINVAL;
2002                 goto errout;
2003         }
2004
2005         ndtmsg = nlmsg_data(nlh);
2006         read_lock(&neigh_tbl_lock);
2007         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
2008                 if (ndtmsg->ndtm_family && tbl->family != ndtmsg->ndtm_family)
2009                         continue;
2010
2011                 if (nla_strcmp(tb[NDTA_NAME], tbl->id) == 0)
2012                         break;
2013         }
2014
2015         if (tbl == NULL) {
2016                 err = -ENOENT;
2017                 goto errout_locked;
2018         }
2019
2020         /*
2021          * We acquire tbl->lock to be nice to the periodic timers and
2022          * make sure they always see a consistent set of values.
2023          */
2024         write_lock_bh(&tbl->lock);
2025
2026         if (tb[NDTA_PARMS]) {
2027                 struct nlattr *tbp[NDTPA_MAX+1];
2028                 struct neigh_parms *p;
2029                 int i, ifindex = 0;
2030
2031                 err = nla_parse_nested(tbp, NDTPA_MAX, tb[NDTA_PARMS],
2032                                        nl_ntbl_parm_policy);
2033                 if (err < 0)
2034                         goto errout_tbl_lock;
2035
2036                 if (tbp[NDTPA_IFINDEX])
2037                         ifindex = nla_get_u32(tbp[NDTPA_IFINDEX]);
2038
2039                 p = lookup_neigh_parms(tbl, net, ifindex);
2040                 if (p == NULL) {
2041                         err = -ENOENT;
2042                         goto errout_tbl_lock;
2043                 }
2044
2045                 for (i = 1; i <= NDTPA_MAX; i++) {
2046                         if (tbp[i] == NULL)
2047                                 continue;
2048
2049                         switch (i) {
2050                         case NDTPA_QUEUE_LEN:
2051                                 NEIGH_VAR_SET(p, QUEUE_LEN_BYTES,
2052                                               nla_get_u32(tbp[i]) *
2053                                               SKB_TRUESIZE(ETH_FRAME_LEN));
2054                                 break;
2055                         case NDTPA_QUEUE_LENBYTES:
2056                                 NEIGH_VAR_SET(p, QUEUE_LEN_BYTES,
2057                                               nla_get_u32(tbp[i]));
2058                                 break;
2059                         case NDTPA_PROXY_QLEN:
2060                                 NEIGH_VAR_SET(p, PROXY_QLEN,
2061                                               nla_get_u32(tbp[i]));
2062                                 break;
2063                         case NDTPA_APP_PROBES:
2064                                 NEIGH_VAR_SET(p, APP_PROBES,
2065                                               nla_get_u32(tbp[i]));
2066                                 break;
2067                         case NDTPA_UCAST_PROBES:
2068                                 NEIGH_VAR_SET(p, UCAST_PROBES,
2069                                               nla_get_u32(tbp[i]));
2070                                 break;
2071                         case NDTPA_MCAST_PROBES:
2072                                 NEIGH_VAR_SET(p, MCAST_PROBES,
2073                                               nla_get_u32(tbp[i]));
2074                                 break;
2075                         case NDTPA_BASE_REACHABLE_TIME:
2076                                 NEIGH_VAR_SET(p, BASE_REACHABLE_TIME,
2077                                               nla_get_msecs(tbp[i]));
2078                                 break;
2079                         case NDTPA_GC_STALETIME:
2080                                 NEIGH_VAR_SET(p, GC_STALETIME,
2081                                               nla_get_msecs(tbp[i]));
2082                                 break;
2083                         case NDTPA_DELAY_PROBE_TIME:
2084                                 NEIGH_VAR_SET(p, DELAY_PROBE_TIME,
2085                                               nla_get_msecs(tbp[i]));
2086                                 break;
2087                         case NDTPA_RETRANS_TIME:
2088                                 NEIGH_VAR_SET(p, RETRANS_TIME,
2089                                               nla_get_msecs(tbp[i]));
2090                                 break;
2091                         case NDTPA_ANYCAST_DELAY:
2092                                 NEIGH_VAR_SET(p, ANYCAST_DELAY,
2093                                               nla_get_msecs(tbp[i]));
2094                                 break;
2095                         case NDTPA_PROXY_DELAY:
2096                                 NEIGH_VAR_SET(p, PROXY_DELAY,
2097                                               nla_get_msecs(tbp[i]));
2098                                 break;
2099                         case NDTPA_LOCKTIME:
2100                                 NEIGH_VAR_SET(p, LOCKTIME,
2101                                               nla_get_msecs(tbp[i]));
2102                                 break;
2103                         }
2104                 }
2105         }
2106
2107         err = -ENOENT;
2108         if ((tb[NDTA_THRESH1] || tb[NDTA_THRESH2] ||
2109              tb[NDTA_THRESH3] || tb[NDTA_GC_INTERVAL]) &&
2110             !net_eq(net, &init_net))
2111                 goto errout_tbl_lock;
2112
2113         if (tb[NDTA_THRESH1])
2114                 tbl->gc_thresh1 = nla_get_u32(tb[NDTA_THRESH1]);
2115
2116         if (tb[NDTA_THRESH2])
2117                 tbl->gc_thresh2 = nla_get_u32(tb[NDTA_THRESH2]);
2118
2119         if (tb[NDTA_THRESH3])
2120                 tbl->gc_thresh3 = nla_get_u32(tb[NDTA_THRESH3]);
2121
2122         if (tb[NDTA_GC_INTERVAL])
2123                 tbl->gc_interval = nla_get_msecs(tb[NDTA_GC_INTERVAL]);
2124
2125         err = 0;
2126
2127 errout_tbl_lock:
2128         write_unlock_bh(&tbl->lock);
2129 errout_locked:
2130         read_unlock(&neigh_tbl_lock);
2131 errout:
2132         return err;
2133 }
2134
2135 static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2136 {
2137         struct net *net = sock_net(skb->sk);
2138         int family, tidx, nidx = 0;
2139         int tbl_skip = cb->args[0];
2140         int neigh_skip = cb->args[1];
2141         struct neigh_table *tbl;
2142
2143         family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;
2144
2145         read_lock(&neigh_tbl_lock);
2146         for (tbl = neigh_tables, tidx = 0; tbl; tbl = tbl->next, tidx++) {
2147                 struct neigh_parms *p;
2148
2149                 if (tidx < tbl_skip || (family && tbl->family != family))
2150                         continue;
2151
2152                 if (neightbl_fill_info(skb, tbl, NETLINK_CB(cb->skb).portid,
2153                                        cb->nlh->nlmsg_seq, RTM_NEWNEIGHTBL,
2154                                        NLM_F_MULTI) <= 0)
2155                         break;
2156
2157                 for (nidx = 0, p = tbl->parms.next; p; p = p->next) {
2158                         if (!net_eq(neigh_parms_net(p), net))
2159                                 continue;
2160
2161                         if (nidx < neigh_skip)
2162                                 goto next;
2163
2164                         if (neightbl_fill_param_info(skb, tbl, p,
2165                                                      NETLINK_CB(cb->skb).portid,
2166                                                      cb->nlh->nlmsg_seq,
2167                                                      RTM_NEWNEIGHTBL,
2168                                                      NLM_F_MULTI) <= 0)
2169                                 goto out;
2170                 next:
2171                         nidx++;
2172                 }
2173
2174                 neigh_skip = 0;
2175         }
2176 out:
2177         read_unlock(&neigh_tbl_lock);
2178         cb->args[0] = tidx;
2179         cb->args[1] = nidx;
2180
2181         return skb->len;
2182 }
2183
2184 static int neigh_fill_info(struct sk_buff *skb, struct neighbour *neigh,
2185                            u32 pid, u32 seq, int type, unsigned int flags)
2186 {
2187         unsigned long now = jiffies;
2188         struct nda_cacheinfo ci;
2189         struct nlmsghdr *nlh;
2190         struct ndmsg *ndm;
2191
2192         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
2193         if (nlh == NULL)
2194                 return -EMSGSIZE;
2195
2196         ndm = nlmsg_data(nlh);
2197         ndm->ndm_family  = neigh->ops->family;
2198         ndm->ndm_pad1    = 0;
2199         ndm->ndm_pad2    = 0;
2200         ndm->ndm_flags   = neigh->flags;
2201         ndm->ndm_type    = neigh->type;
2202         ndm->ndm_ifindex = neigh->dev->ifindex;
2203
2204         if (nla_put(skb, NDA_DST, neigh->tbl->key_len, neigh->primary_key))
2205                 goto nla_put_failure;
2206
2207         read_lock_bh(&neigh->lock);
2208         ndm->ndm_state   = neigh->nud_state;
2209         if (neigh->nud_state & NUD_VALID) {
2210                 char haddr[MAX_ADDR_LEN];
2211
2212                 neigh_ha_snapshot(haddr, neigh, neigh->dev);
2213                 if (nla_put(skb, NDA_LLADDR, neigh->dev->addr_len, haddr) < 0) {
2214                         read_unlock_bh(&neigh->lock);
2215                         goto nla_put_failure;
2216                 }
2217         }
2218
2219         ci.ndm_used      = jiffies_to_clock_t(now - neigh->used);
2220         ci.ndm_confirmed = jiffies_to_clock_t(now - neigh->confirmed);
2221         ci.ndm_updated   = jiffies_to_clock_t(now - neigh->updated);
2222         ci.ndm_refcnt    = atomic_read(&neigh->refcnt) - 1;
2223         read_unlock_bh(&neigh->lock);
2224
2225         if (nla_put_u32(skb, NDA_PROBES, atomic_read(&neigh->probes)) ||
2226             nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
2227                 goto nla_put_failure;
2228
2229         return nlmsg_end(skb, nlh);
2230
2231 nla_put_failure:
2232         nlmsg_cancel(skb, nlh);
2233         return -EMSGSIZE;
2234 }
2235
2236 static int pneigh_fill_info(struct sk_buff *skb, struct pneigh_entry *pn,
2237                             u32 pid, u32 seq, int type, unsigned int flags,
2238                             struct neigh_table *tbl)
2239 {
2240         struct nlmsghdr *nlh;
2241         struct ndmsg *ndm;
2242
2243         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
2244         if (nlh == NULL)
2245                 return -EMSGSIZE;
2246
2247         ndm = nlmsg_data(nlh);
2248         ndm->ndm_family  = tbl->family;
2249         ndm->ndm_pad1    = 0;
2250         ndm->ndm_pad2    = 0;
2251         ndm->ndm_flags   = pn->flags | NTF_PROXY;
2252         ndm->ndm_type    = RTN_UNICAST;
2253         ndm->ndm_ifindex = pn->dev->ifindex;
2254         ndm->ndm_state   = NUD_NONE;
2255
2256         if (nla_put(skb, NDA_DST, tbl->key_len, pn->key))
2257                 goto nla_put_failure;
2258
2259         return nlmsg_end(skb, nlh);
2260
2261 nla_put_failure:
2262         nlmsg_cancel(skb, nlh);
2263         return -EMSGSIZE;
2264 }
2265
2266 static void neigh_update_notify(struct neighbour *neigh)
2267 {
2268         call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
2269         __neigh_notify(neigh, RTM_NEWNEIGH, 0);
2270 }
2271
2272 static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
2273                             struct netlink_callback *cb)
2274 {
2275         struct net *net = sock_net(skb->sk);
2276         struct neighbour *n;
2277         int rc, h, s_h = cb->args[1];
2278         int idx, s_idx = idx = cb->args[2];
2279         struct neigh_hash_table *nht;
2280
2281         rcu_read_lock_bh();
2282         nht = rcu_dereference_bh(tbl->nht);
2283
2284         for (h = s_h; h < (1 << nht->hash_shift); h++) {
2285                 if (h > s_h)
2286                         s_idx = 0;
2287                 for (n = rcu_dereference_bh(nht->hash_buckets[h]), idx = 0;
2288                      n != NULL;
2289                      n = rcu_dereference_bh(n->next)) {
2290                         if (!net_eq(dev_net(n->dev), net))
2291                                 continue;
2292                         if (idx < s_idx)
2293                                 goto next;
2294                         if (neigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,
2295                                             cb->nlh->nlmsg_seq,
2296                                             RTM_NEWNEIGH,
2297                                             NLM_F_MULTI) <= 0) {
2298                                 rc = -1;
2299                                 goto out;
2300                         }
2301 next:
2302                         idx++;
2303                 }
2304         }
2305         rc = skb->len;
2306 out:
2307         rcu_read_unlock_bh();
2308         cb->args[1] = h;
2309         cb->args[2] = idx;
2310         return rc;
2311 }
2312
2313 static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
2314                              struct netlink_callback *cb)
2315 {
2316         struct pneigh_entry *n;
2317         struct net *net = sock_net(skb->sk);
2318         int rc, h, s_h = cb->args[3];
2319         int idx, s_idx = idx = cb->args[4];
2320
2321         read_lock_bh(&tbl->lock);
2322
2323         for (h = s_h; h <= PNEIGH_HASHMASK; h++) {
2324                 if (h > s_h)
2325                         s_idx = 0;
2326                 for (n = tbl->phash_buckets[h], idx = 0; n; n = n->next) {
2327                         if (dev_net(n->dev) != net)
2328                                 continue;
2329                         if (idx < s_idx)
2330                                 goto next;
2331                         if (pneigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,
2332                                             cb->nlh->nlmsg_seq,
2333                                             RTM_NEWNEIGH,
2334                                             NLM_F_MULTI, tbl) <= 0) {
2335                                 read_unlock_bh(&tbl->lock);
2336                                 rc = -1;
2337                                 goto out;
2338                         }
2339                 next:
2340                         idx++;
2341                 }
2342         }
2343
2344         read_unlock_bh(&tbl->lock);
2345         rc = skb->len;
2346 out:
2347         cb->args[3] = h;
2348         cb->args[4] = idx;
2349         return rc;
2350
2351 }
2352
2353 static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2354 {
2355         struct neigh_table *tbl;
2356         int t, family, s_t;
2357         int proxy = 0;
2358         int err;
2359
2360         read_lock(&neigh_tbl_lock);
2361         family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;
2362
2363         /* check for full ndmsg structure presence, family member is
2364          * the same for both structures
2365          */
2366         if (nlmsg_len(cb->nlh) >= sizeof(struct ndmsg) &&
2367             ((struct ndmsg *) nlmsg_data(cb->nlh))->ndm_flags == NTF_PROXY)
2368                 proxy = 1;
2369
2370         s_t = cb->args[0];
2371
2372         for (tbl = neigh_tables, t = 0; tbl;
2373              tbl = tbl->next, t++) {
2374                 if (t < s_t || (family && tbl->family != family))
2375                         continue;
2376                 if (t > s_t)
2377                         memset(&cb->args[1], 0, sizeof(cb->args) -
2378                                                 sizeof(cb->args[0]));
2379                 if (proxy)
2380                         err = pneigh_dump_table(tbl, skb, cb);
2381                 else
2382                         err = neigh_dump_table(tbl, skb, cb);
2383                 if (err < 0)
2384                         break;
2385         }
2386         read_unlock(&neigh_tbl_lock);
2387
2388         cb->args[0] = t;
2389         return skb->len;
2390 }
2391
2392 void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie)
2393 {
2394         int chain;
2395         struct neigh_hash_table *nht;
2396
2397         rcu_read_lock_bh();
2398         nht = rcu_dereference_bh(tbl->nht);
2399
2400         read_lock(&tbl->lock); /* avoid resizes */
2401         for (chain = 0; chain < (1 << nht->hash_shift); chain++) {
2402                 struct neighbour *n;
2403
2404                 for (n = rcu_dereference_bh(nht->hash_buckets[chain]);
2405                      n != NULL;
2406                      n = rcu_dereference_bh(n->next))
2407                         cb(n, cookie);
2408         }
2409         read_unlock(&tbl->lock);
2410         rcu_read_unlock_bh();
2411 }
2412 EXPORT_SYMBOL(neigh_for_each);
2413
2414 /* The tbl->lock must be held as a writer and BH disabled. */
2415 void __neigh_for_each_release(struct neigh_table *tbl,
2416                               int (*cb)(struct neighbour *))
2417 {
2418         int chain;
2419         struct neigh_hash_table *nht;
2420
2421         nht = rcu_dereference_protected(tbl->nht,
2422                                         lockdep_is_held(&tbl->lock));
2423         for (chain = 0; chain < (1 << nht->hash_shift); chain++) {
2424                 struct neighbour *n;
2425                 struct neighbour __rcu **np;
2426
2427                 np = &nht->hash_buckets[chain];
2428                 while ((n = rcu_dereference_protected(*np,
2429                                         lockdep_is_held(&tbl->lock))) != NULL) {
2430                         int release;
2431
2432                         write_lock(&n->lock);
2433                         release = cb(n);
2434                         if (release) {
2435                                 rcu_assign_pointer(*np,
2436                                         rcu_dereference_protected(n->next,
2437                                                 lockdep_is_held(&tbl->lock)));
2438                                 n->dead = 1;
2439                         } else
2440                                 np = &n->next;
2441                         write_unlock(&n->lock);
2442                         if (release)
2443                                 neigh_cleanup_and_release(n);
2444                 }
2445         }
2446 }
2447 EXPORT_SYMBOL(__neigh_for_each_release);
2448
2449 #ifdef CONFIG_PROC_FS
2450
2451 static struct neighbour *neigh_get_first(struct seq_file *seq)
2452 {
2453         struct neigh_seq_state *state = seq->private;
2454         struct net *net = seq_file_net(seq);
2455         struct neigh_hash_table *nht = state->nht;
2456         struct neighbour *n = NULL;
2457         int bucket = state->bucket;
2458
2459         state->flags &= ~NEIGH_SEQ_IS_PNEIGH;
2460         for (bucket = 0; bucket < (1 << nht->hash_shift); bucket++) {
2461                 n = rcu_dereference_bh(nht->hash_buckets[bucket]);
2462
2463                 while (n) {
2464                         if (!net_eq(dev_net(n->dev), net))
2465                                 goto next;
2466                         if (state->neigh_sub_iter) {
2467                                 loff_t fakep = 0;
2468                                 void *v;
2469
2470                                 v = state->neigh_sub_iter(state, n, &fakep);
2471                                 if (!v)
2472                                         goto next;
2473                         }
2474                         if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
2475                                 break;
2476                         if (n->nud_state & ~NUD_NOARP)
2477                                 break;
2478 next:
2479                         n = rcu_dereference_bh(n->next);
2480                 }
2481
2482                 if (n)
2483                         break;
2484         }
2485         state->bucket = bucket;
2486
2487         return n;
2488 }
2489
2490 static struct neighbour *neigh_get_next(struct seq_file *seq,
2491                                         struct neighbour *n,
2492                                         loff_t *pos)
2493 {
2494         struct neigh_seq_state *state = seq->private;
2495         struct net *net = seq_file_net(seq);
2496         struct neigh_hash_table *nht = state->nht;
2497
2498         if (state->neigh_sub_iter) {
2499                 void *v = state->neigh_sub_iter(state, n, pos);
2500                 if (v)
2501                         return n;
2502         }
2503         n = rcu_dereference_bh(n->next);
2504
2505         while (1) {
2506                 while (n) {
2507                         if (!net_eq(dev_net(n->dev), net))
2508                                 goto next;
2509                         if (state->neigh_sub_iter) {
2510                                 void *v = state->neigh_sub_iter(state, n, pos);
2511                                 if (v)
2512                                         return n;
2513                                 goto next;
2514                         }
2515                         if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
2516                                 break;
2517
2518                         if (n->nud_state & ~NUD_NOARP)
2519                                 break;
2520 next:
2521                         n = rcu_dereference_bh(n->next);
2522                 }
2523
2524                 if (n)
2525                         break;
2526
2527                 if (++state->bucket >= (1 << nht->hash_shift))
2528                         break;
2529
2530                 n = rcu_dereference_bh(nht->hash_buckets[state->bucket]);
2531         }
2532
2533         if (n && pos)
2534                 --(*pos);
2535         return n;
2536 }
2537
2538 static struct neighbour *neigh_get_idx(struct seq_file *seq, loff_t *pos)
2539 {
2540         struct neighbour *n = neigh_get_first(seq);
2541
2542         if (n) {
2543                 --(*pos);
2544                 while (*pos) {
2545                         n = neigh_get_next(seq, n, pos);
2546                         if (!n)
2547                                 break;
2548                 }
2549         }
2550         return *pos ? NULL : n;
2551 }
2552
2553 static struct pneigh_entry *pneigh_get_first(struct seq_file *seq)
2554 {
2555         struct neigh_seq_state *state = seq->private;
2556         struct net *net = seq_file_net(seq);
2557         struct neigh_table *tbl = state->tbl;
2558         struct pneigh_entry *pn = NULL;
2559         int bucket = state->bucket;
2560
2561         state->flags |= NEIGH_SEQ_IS_PNEIGH;
2562         for (bucket = 0; bucket <= PNEIGH_HASHMASK; bucket++) {
2563                 pn = tbl->phash_buckets[bucket];
2564                 while (pn && !net_eq(pneigh_net(pn), net))
2565                         pn = pn->next;
2566                 if (pn)
2567                         break;
2568         }
2569         state->bucket = bucket;
2570
2571         return pn;
2572 }
2573
2574 static struct pneigh_entry *pneigh_get_next(struct seq_file *seq,
2575                                             struct pneigh_entry *pn,
2576                                             loff_t *pos)
2577 {
2578         struct neigh_seq_state *state = seq->private;
2579         struct net *net = seq_file_net(seq);
2580         struct neigh_table *tbl = state->tbl;
2581
2582         do {
2583                 pn = pn->next;
2584         } while (pn && !net_eq(pneigh_net(pn), net));
2585
2586         while (!pn) {
2587                 if (++state->bucket > PNEIGH_HASHMASK)
2588                         break;
2589                 pn = tbl->phash_buckets[state->bucket];
2590                 while (pn && !net_eq(pneigh_net(pn), net))
2591                         pn = pn->next;
2592                 if (pn)
2593                         break;
2594         }
2595
2596         if (pn && pos)
2597                 --(*pos);
2598
2599         return pn;
2600 }
2601
2602 static struct pneigh_entry *pneigh_get_idx(struct seq_file *seq, loff_t *pos)
2603 {
2604         struct pneigh_entry *pn = pneigh_get_first(seq);
2605
2606         if (pn) {
2607                 --(*pos);
2608                 while (*pos) {
2609                         pn = pneigh_get_next(seq, pn, pos);
2610                         if (!pn)
2611                                 break;
2612                 }
2613         }
2614         return *pos ? NULL : pn;
2615 }
2616
2617 static void *neigh_get_idx_any(struct seq_file *seq, loff_t *pos)
2618 {
2619         struct neigh_seq_state *state = seq->private;
2620         void *rc;
2621         loff_t idxpos = *pos;
2622
2623         rc = neigh_get_idx(seq, &idxpos);
2624         if (!rc && !(state->flags & NEIGH_SEQ_NEIGH_ONLY))
2625                 rc = pneigh_get_idx(seq, &idxpos);
2626
2627         return rc;
2628 }
2629
2630 void *neigh_seq_start(struct seq_file *seq, loff_t *pos, struct neigh_table *tbl, unsigned int neigh_seq_flags)
2631         __acquires(rcu_bh)
2632 {
2633         struct neigh_seq_state *state = seq->private;
2634
2635         state->tbl = tbl;
2636         state->bucket = 0;
2637         state->flags = (neigh_seq_flags & ~NEIGH_SEQ_IS_PNEIGH);
2638
2639         rcu_read_lock_bh();
2640         state->nht = rcu_dereference_bh(tbl->nht);
2641
2642         return *pos ? neigh_get_idx_any(seq, pos) : SEQ_START_TOKEN;
2643 }
2644 EXPORT_SYMBOL(neigh_seq_start);
2645
2646 void *neigh_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2647 {
2648         struct neigh_seq_state *state;
2649         void *rc;
2650
2651         if (v == SEQ_START_TOKEN) {
2652                 rc = neigh_get_first(seq);
2653                 goto out;
2654         }
2655
2656         state = seq->private;
2657         if (!(state->flags & NEIGH_SEQ_IS_PNEIGH)) {
2658                 rc = neigh_get_next(seq, v, NULL);
2659                 if (rc)
2660                         goto out;
2661                 if (!(state->flags & NEIGH_SEQ_NEIGH_ONLY))
2662                         rc = pneigh_get_first(seq);
2663         } else {
2664                 BUG_ON(state->flags & NEIGH_SEQ_NEIGH_ONLY);
2665                 rc = pneigh_get_next(seq, v, NULL);
2666         }
2667 out:
2668         ++(*pos);
2669         return rc;
2670 }
2671 EXPORT_SYMBOL(neigh_seq_next);
2672
2673 void neigh_seq_stop(struct seq_file *seq, void *v)
2674         __releases(rcu_bh)
2675 {
2676         rcu_read_unlock_bh();
2677 }
2678 EXPORT_SYMBOL(neigh_seq_stop);
2679
2680 /* statistics via seq_file */
2681
2682 static void *neigh_stat_seq_start(struct seq_file *seq, loff_t *pos)
2683 {
2684         struct neigh_table *tbl = seq->private;
2685         int cpu;
2686
2687         if (*pos == 0)
2688                 return SEQ_START_TOKEN;
2689
2690         for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
2691                 if (!cpu_possible(cpu))
2692                         continue;
2693                 *pos = cpu+1;
2694                 return per_cpu_ptr(tbl->stats, cpu);
2695         }
2696         return NULL;
2697 }
2698
2699 static void *neigh_stat_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2700 {
2701         struct neigh_table *tbl = seq->private;
2702         int cpu;
2703
2704         for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
2705                 if (!cpu_possible(cpu))
2706                         continue;
2707                 *pos = cpu+1;
2708                 return per_cpu_ptr(tbl->stats, cpu);
2709         }
2710         return NULL;
2711 }
2712
2713 static void neigh_stat_seq_stop(struct seq_file *seq, void *v)
2714 {
2715
2716 }
2717
2718 static int neigh_stat_seq_show(struct seq_file *seq, void *v)
2719 {
2720         struct neigh_table *tbl = seq->private;
2721         struct neigh_statistics *st = v;
2722
2723         if (v == SEQ_START_TOKEN) {
2724                 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");
2725                 return 0;
2726         }
2727
2728         seq_printf(seq, "%08x  %08lx %08lx %08lx  %08lx %08lx  %08lx  "
2729                         "%08lx %08lx  %08lx %08lx %08lx\n",
2730                    atomic_read(&tbl->entries),
2731
2732                    st->allocs,
2733                    st->destroys,
2734                    st->hash_grows,
2735
2736                    st->lookups,
2737                    st->hits,
2738
2739                    st->res_failed,
2740
2741                    st->rcv_probes_mcast,
2742                    st->rcv_probes_ucast,
2743
2744                    st->periodic_gc_runs,
2745                    st->forced_gc_runs,
2746                    st->unres_discards
2747                    );
2748
2749         return 0;
2750 }
2751
2752 static const struct seq_operations neigh_stat_seq_ops = {
2753         .start  = neigh_stat_seq_start,
2754         .next   = neigh_stat_seq_next,
2755         .stop   = neigh_stat_seq_stop,
2756         .show   = neigh_stat_seq_show,
2757 };
2758
2759 static int neigh_stat_seq_open(struct inode *inode, struct file *file)
2760 {
2761         int ret = seq_open(file, &neigh_stat_seq_ops);
2762
2763         if (!ret) {
2764                 struct seq_file *sf = file->private_data;
2765                 sf->private = PDE_DATA(inode);
2766         }
2767         return ret;
2768 };
2769
2770 static const struct file_operations neigh_stat_seq_fops = {
2771         .owner   = THIS_MODULE,
2772         .open    = neigh_stat_seq_open,
2773         .read    = seq_read,
2774         .llseek  = seq_lseek,
2775         .release = seq_release,
2776 };
2777
2778 #endif /* CONFIG_PROC_FS */
2779
2780 static inline size_t neigh_nlmsg_size(void)
2781 {
2782         return NLMSG_ALIGN(sizeof(struct ndmsg))
2783                + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
2784                + nla_total_size(MAX_ADDR_LEN) /* NDA_LLADDR */
2785                + nla_total_size(sizeof(struct nda_cacheinfo))
2786                + nla_total_size(4); /* NDA_PROBES */
2787 }
2788
2789 static void __neigh_notify(struct neighbour *n, int type, int flags)
2790 {
2791         struct net *net = dev_net(n->dev);
2792         struct sk_buff *skb;
2793         int err = -ENOBUFS;
2794
2795         skb = nlmsg_new(neigh_nlmsg_size(), GFP_ATOMIC);
2796         if (skb == NULL)
2797                 goto errout;
2798
2799         err = neigh_fill_info(skb, n, 0, 0, type, flags);
2800         if (err < 0) {
2801                 /* -EMSGSIZE implies BUG in neigh_nlmsg_size() */
2802                 WARN_ON(err == -EMSGSIZE);
2803                 kfree_skb(skb);
2804                 goto errout;
2805         }
2806         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
2807         return;
2808 errout:
2809         if (err < 0)
2810                 rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
2811 }
2812
2813 void neigh_app_ns(struct neighbour *n)
2814 {
2815         __neigh_notify(n, RTM_GETNEIGH, NLM_F_REQUEST);
2816 }
2817 EXPORT_SYMBOL(neigh_app_ns);
2818
2819 #ifdef CONFIG_SYSCTL
2820 static int zero;
2821 static int int_max = INT_MAX;
2822 static int unres_qlen_max = INT_MAX / SKB_TRUESIZE(ETH_FRAME_LEN);
2823
2824 static int proc_unres_qlen(struct ctl_table *ctl, int write,
2825                            void __user *buffer, size_t *lenp, loff_t *ppos)
2826 {
2827         int size, ret;
2828         struct ctl_table tmp = *ctl;
2829
2830         tmp.extra1 = &zero;
2831         tmp.extra2 = &unres_qlen_max;
2832         tmp.data = &size;
2833
2834         size = *(int *)ctl->data / SKB_TRUESIZE(ETH_FRAME_LEN);
2835         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2836
2837         if (write && !ret)
2838                 *(int *)ctl->data = size * SKB_TRUESIZE(ETH_FRAME_LEN);
2839         return ret;
2840 }
2841
2842 static struct neigh_parms *neigh_get_dev_parms_rcu(struct net_device *dev,
2843                                                    int family)
2844 {
2845         switch (family) {
2846         case AF_INET:
2847                 return __in_dev_arp_parms_get_rcu(dev);
2848         case AF_INET6:
2849                 return __in6_dev_nd_parms_get_rcu(dev);
2850         }
2851         return NULL;
2852 }
2853
2854 static void neigh_copy_dflt_parms(struct net *net, struct neigh_parms *p,
2855                                   int index)
2856 {
2857         struct net_device *dev;
2858         int family = neigh_parms_family(p);
2859
2860         rcu_read_lock();
2861         for_each_netdev_rcu(net, dev) {
2862                 struct neigh_parms *dst_p =
2863                                 neigh_get_dev_parms_rcu(dev, family);
2864
2865                 if (dst_p && !test_bit(index, dst_p->data_state))
2866                         dst_p->data[index] = p->data[index];
2867         }
2868         rcu_read_unlock();
2869 }
2870
2871 static void neigh_proc_update(struct ctl_table *ctl, int write)
2872 {
2873         struct net_device *dev = ctl->extra1;
2874         struct neigh_parms *p = ctl->extra2;
2875         struct net *net = neigh_parms_net(p);
2876         int index = (int *) ctl->data - p->data;
2877
2878         if (!write)
2879                 return;
2880
2881         set_bit(index, p->data_state);
2882         if (!dev) /* NULL dev means this is default value */
2883                 neigh_copy_dflt_parms(net, p, index);
2884 }
2885
2886 static int neigh_proc_dointvec_zero_intmax(struct ctl_table *ctl, int write,
2887                                            void __user *buffer,
2888                                            size_t *lenp, loff_t *ppos)
2889 {
2890         struct ctl_table tmp = *ctl;
2891         int ret;
2892
2893         tmp.extra1 = &zero;
2894         tmp.extra2 = &int_max;
2895
2896         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2897         neigh_proc_update(ctl, write);
2898         return ret;
2899 }
2900
2901 int neigh_proc_dointvec(struct ctl_table *ctl, int write,
2902                         void __user *buffer, size_t *lenp, loff_t *ppos)
2903 {
2904         int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
2905
2906         neigh_proc_update(ctl, write);
2907         return ret;
2908 }
2909 EXPORT_SYMBOL(neigh_proc_dointvec);
2910
2911 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
2912                                 void __user *buffer,
2913                                 size_t *lenp, loff_t *ppos)
2914 {
2915         int ret = proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos);
2916
2917         neigh_proc_update(ctl, write);
2918         return ret;
2919 }
2920 EXPORT_SYMBOL(neigh_proc_dointvec_jiffies);
2921
2922 static int neigh_proc_dointvec_userhz_jiffies(struct ctl_table *ctl, int write,
2923                                               void __user *buffer,
2924                                               size_t *lenp, loff_t *ppos)
2925 {
2926         int ret = proc_dointvec_userhz_jiffies(ctl, write, buffer, lenp, ppos);
2927
2928         neigh_proc_update(ctl, write);
2929         return ret;
2930 }
2931
2932 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
2933                                    void __user *buffer,
2934                                    size_t *lenp, loff_t *ppos)
2935 {
2936         int ret = proc_dointvec_ms_jiffies(ctl, write, buffer, lenp, ppos);
2937
2938         neigh_proc_update(ctl, write);
2939         return ret;
2940 }
2941 EXPORT_SYMBOL(neigh_proc_dointvec_ms_jiffies);
2942
2943 static int neigh_proc_dointvec_unres_qlen(struct ctl_table *ctl, int write,
2944                                           void __user *buffer,
2945                                           size_t *lenp, loff_t *ppos)
2946 {
2947         int ret = proc_unres_qlen(ctl, write, buffer, lenp, ppos);
2948
2949         neigh_proc_update(ctl, write);
2950         return ret;
2951 }
2952
2953 #define NEIGH_PARMS_DATA_OFFSET(index)  \
2954         (&((struct neigh_parms *) 0)->data[index])
2955
2956 #define NEIGH_SYSCTL_ENTRY(attr, data_attr, name, mval, proc) \
2957         [NEIGH_VAR_ ## attr] = { \
2958                 .procname       = name, \
2959                 .data           = NEIGH_PARMS_DATA_OFFSET(NEIGH_VAR_ ## data_attr), \
2960                 .maxlen         = sizeof(int), \
2961                 .mode           = mval, \
2962                 .proc_handler   = proc, \
2963         }
2964
2965 #define NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(attr, name) \
2966         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_zero_intmax)
2967
2968 #define NEIGH_SYSCTL_JIFFIES_ENTRY(attr, name) \
2969         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_jiffies)
2970
2971 #define NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(attr, name) \
2972         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_userhz_jiffies)
2973
2974 #define NEIGH_SYSCTL_MS_JIFFIES_ENTRY(attr, name) \
2975         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_ms_jiffies)
2976
2977 #define NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(attr, data_attr, name) \
2978         NEIGH_SYSCTL_ENTRY(attr, data_attr, name, 0644, neigh_proc_dointvec_ms_jiffies)
2979
2980 #define NEIGH_SYSCTL_UNRES_QLEN_REUSED_ENTRY(attr, data_attr, name) \
2981         NEIGH_SYSCTL_ENTRY(attr, data_attr, name, 0644, neigh_proc_dointvec_unres_qlen)
2982
2983 static struct neigh_sysctl_table {
2984         struct ctl_table_header *sysctl_header;
2985         struct ctl_table neigh_vars[NEIGH_VAR_MAX + 1];
2986 } neigh_sysctl_template __read_mostly = {
2987         .neigh_vars = {
2988                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(MCAST_PROBES, "mcast_solicit"),
2989                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(UCAST_PROBES, "ucast_solicit"),
2990                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(APP_PROBES, "app_solicit"),
2991                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(RETRANS_TIME, "retrans_time"),
2992                 NEIGH_SYSCTL_JIFFIES_ENTRY(BASE_REACHABLE_TIME, "base_reachable_time"),
2993                 NEIGH_SYSCTL_JIFFIES_ENTRY(DELAY_PROBE_TIME, "delay_first_probe_time"),
2994                 NEIGH_SYSCTL_JIFFIES_ENTRY(GC_STALETIME, "gc_stale_time"),
2995                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(QUEUE_LEN_BYTES, "unres_qlen_bytes"),
2996                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(PROXY_QLEN, "proxy_qlen"),
2997                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(ANYCAST_DELAY, "anycast_delay"),
2998                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(PROXY_DELAY, "proxy_delay"),
2999                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(LOCKTIME, "locktime"),
3000                 NEIGH_SYSCTL_UNRES_QLEN_REUSED_ENTRY(QUEUE_LEN, QUEUE_LEN_BYTES, "unres_qlen"),
3001                 NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(RETRANS_TIME_MS, RETRANS_TIME, "retrans_time_ms"),
3002                 NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(BASE_REACHABLE_TIME_MS, BASE_REACHABLE_TIME, "base_reachable_time_ms"),
3003                 [NEIGH_VAR_GC_INTERVAL] = {
3004                         .procname       = "gc_interval",
3005                         .maxlen         = sizeof(int),
3006                         .mode           = 0644,
3007                         .proc_handler   = proc_dointvec_jiffies,
3008                 },
3009                 [NEIGH_VAR_GC_THRESH1] = {
3010                         .procname       = "gc_thresh1",
3011                         .maxlen         = sizeof(int),
3012                         .mode           = 0644,
3013                         .extra1         = &zero,
3014                         .extra2         = &int_max,
3015                         .proc_handler   = proc_dointvec_minmax,
3016                 },
3017                 [NEIGH_VAR_GC_THRESH2] = {
3018                         .procname       = "gc_thresh2",
3019                         .maxlen         = sizeof(int),
3020                         .mode           = 0644,
3021                         .extra1         = &zero,
3022                         .extra2         = &int_max,
3023                         .proc_handler   = proc_dointvec_minmax,
3024                 },
3025                 [NEIGH_VAR_GC_THRESH3] = {
3026                         .procname       = "gc_thresh3",
3027                         .maxlen         = sizeof(int),
3028                         .mode           = 0644,
3029                         .extra1         = &zero,
3030                         .extra2         = &int_max,
3031                         .proc_handler   = proc_dointvec_minmax,
3032                 },
3033                 {},
3034         },
3035 };
3036
3037 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
3038                           proc_handler *handler)
3039 {
3040         int i;
3041         struct neigh_sysctl_table *t;
3042         const char *dev_name_source;
3043         char neigh_path[ sizeof("net//neigh/") + IFNAMSIZ + IFNAMSIZ ];
3044         char *p_name;
3045
3046         t = kmemdup(&neigh_sysctl_template, sizeof(*t), GFP_KERNEL);
3047         if (!t)
3048                 goto err;
3049
3050         for (i = 0; i < NEIGH_VAR_GC_INTERVAL; i++) {
3051                 t->neigh_vars[i].data += (long) p;
3052                 t->neigh_vars[i].extra1 = dev;
3053                 t->neigh_vars[i].extra2 = p;
3054         }
3055
3056         if (dev) {
3057                 dev_name_source = dev->name;
3058                 /* Terminate the table early */
3059                 memset(&t->neigh_vars[NEIGH_VAR_GC_INTERVAL], 0,
3060                        sizeof(t->neigh_vars[NEIGH_VAR_GC_INTERVAL]));
3061         } else {
3062                 struct neigh_table *tbl = p->tbl;
3063                 dev_name_source = "default";
3064                 t->neigh_vars[NEIGH_VAR_GC_INTERVAL].data = &tbl->gc_interval;
3065                 t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = &tbl->gc_thresh1;
3066                 t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = &tbl->gc_thresh2;
3067                 t->neigh_vars[NEIGH_VAR_GC_THRESH3].data = &tbl->gc_thresh3;
3068         }
3069
3070         if (handler) {
3071                 /* RetransTime */
3072                 t->neigh_vars[NEIGH_VAR_RETRANS_TIME].proc_handler = handler;
3073                 /* ReachableTime */
3074                 t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].proc_handler = handler;
3075                 /* RetransTime (in milliseconds)*/
3076                 t->neigh_vars[NEIGH_VAR_RETRANS_TIME_MS].proc_handler = handler;
3077                 /* ReachableTime (in milliseconds) */
3078                 t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].proc_handler = handler;
3079         }
3080
3081         /* Don't export sysctls to unprivileged users */
3082         if (neigh_parms_net(p)->user_ns != &init_user_ns)
3083                 t->neigh_vars[0].procname = NULL;
3084
3085         switch (neigh_parms_family(p)) {
3086         case AF_INET:
3087               p_name = "ipv4";
3088               break;
3089         case AF_INET6:
3090               p_name = "ipv6";
3091               break;
3092         default:
3093               BUG();
3094         }
3095
3096         snprintf(neigh_path, sizeof(neigh_path), "net/%s/neigh/%s",
3097                 p_name, dev_name_source);
3098         t->sysctl_header =
3099                 register_net_sysctl(neigh_parms_net(p), neigh_path, t->neigh_vars);
3100         if (!t->sysctl_header)
3101                 goto free;
3102
3103         p->sysctl_table = t;
3104         return 0;
3105
3106 free:
3107         kfree(t);
3108 err:
3109         return -ENOBUFS;
3110 }
3111 EXPORT_SYMBOL(neigh_sysctl_register);
3112
3113 void neigh_sysctl_unregister(struct neigh_parms *p)
3114 {
3115         if (p->sysctl_table) {
3116                 struct neigh_sysctl_table *t = p->sysctl_table;
3117                 p->sysctl_table = NULL;
3118                 unregister_net_sysctl_table(t->sysctl_header);
3119                 kfree(t);
3120         }
3121 }
3122 EXPORT_SYMBOL(neigh_sysctl_unregister);
3123
3124 #endif  /* CONFIG_SYSCTL */
3125
3126 static int __init neigh_init(void)
3127 {
3128         rtnl_register(PF_UNSPEC, RTM_NEWNEIGH, neigh_add, NULL, NULL);
3129         rtnl_register(PF_UNSPEC, RTM_DELNEIGH, neigh_delete, NULL, NULL);
3130         rtnl_register(PF_UNSPEC, RTM_GETNEIGH, NULL, neigh_dump_info, NULL);
3131
3132         rtnl_register(PF_UNSPEC, RTM_GETNEIGHTBL, NULL, neightbl_dump_info,
3133                       NULL);
3134         rtnl_register(PF_UNSPEC, RTM_SETNEIGHTBL, neightbl_set, NULL, NULL);
3135
3136         return 0;
3137 }
3138
3139 subsys_initcall(neigh_init);
3140