net/core/neighbour.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Generic address resolution entity
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <[email protected]>
   7  *      Alexey Kuznetsov        <[email protected]>
   8  *
   9  *      Fixes:
  10  *      Vitaly E. Lavrov        releasing NULL neighbor in neigh_add.
  11  *      Harald Welte            Add neighbour cache statistics like rtstat
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/slab.h>
  17 #include <linux/kmemleak.h>
  18 #include <linux/types.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/socket.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/proc_fs.h>
  24 #ifdef CONFIG_SYSCTL
  25 #include <linux/sysctl.h>
  26 #endif
  27 #include <linux/times.h>
  28 #include <net/net_namespace.h>
  29 #include <net/neighbour.h>
  30 #include <net/arp.h>
  31 #include <net/dst.h>
  32 #include <net/sock.h>
  33 #include <net/netevent.h>
  34 #include <net/netlink.h>
  35 #include <linux/rtnetlink.h>
  36 #include <linux/random.h>
  37 #include <linux/string.h>
  38 #include <linux/log2.h>
  39 #include <linux/inetdevice.h>
  40 #include <net/addrconf.h>
  41
  42 #include <trace/events/neigh.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(struct timer_list *t);
  55 static void __neigh_notify(struct neighbour *n, int type, int flags,
  56                            u32 pid);
  57 static void neigh_update_notify(struct neighbour *neigh, u32 nlmsg_pid);
  58 static int pneigh_ifdown_and_unlock(struct neigh_table *tbl,
  59                                     struct net_device *dev);
  60
  61 #ifdef CONFIG_PROC_FS
  62 static const struct seq_operations neigh_stat_seq_ops;
  63 #endif
  64
  65 /*
  66    Neighbour hash table buckets are protected with rwlock tbl->lock.
  67
  68    - All the scans/updates to hash buckets MUST be made under this lock.
  69    - NOTHING clever should be made under this lock: no callbacks
  70      to protocol backends, no attempts to send something to network.
  71      It will result in deadlocks, if backend/driver wants to use neighbour
  72      cache.
  73    - If the entry requires some non-trivial actions, increase
  74      its reference count and release table lock.
  75
  76    Neighbour entries are protected:
  77    - with reference count.
  78    - with rwlock neigh->lock
  79
  80    Reference count prevents destruction.
  81
  82    neigh->lock mainly serializes ll address data and its validity state.
  83    However, the same lock is used to protect another entry fields:
  84     - timer
  85     - resolution queue
  86
  87    Again, nothing clever shall be made under neigh->lock,
  88    the most complicated procedure, which we allow is dev->hard_header.
  89    It is supposed, that dev->hard_header is simplistic and does
  90    not make callbacks to neighbour tables.
  91  */
  92
  93 static int neigh_blackhole(struct neighbour *neigh, struct sk_buff *skb)
  94 {
  95         kfree_skb(skb);
  96         return -ENETDOWN;
  97 }
  98
  99 static void neigh_cleanup_and_release(struct neighbour *neigh)
 100 {
 101         if (neigh->parms->neigh_cleanup)
 102                 neigh->parms->neigh_cleanup(neigh);
 103
 104         trace_neigh_cleanup_and_release(neigh, 0);
 105         __neigh_notify(neigh, RTM_DELNEIGH, 0, 0);
 106         call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
 107         neigh_release(neigh);
 108 }
 109
 110 /*
 111  * It is random distribution in the interval (1/2)*base...(3/2)*base.
 112  * It corresponds to default IPv6 settings and is not overridable,
 113  * because it is really reasonable choice.
 114  */
 115
 116 unsigned long neigh_rand_reach_time(unsigned long base)
 117 {
 118         return base ? (prandom_u32() % base) + (base >> 1) : 0;
 119 }
 120 EXPORT_SYMBOL(neigh_rand_reach_time);
 121
 122 static void neigh_mark_dead(struct neighbour *n)
 123 {
 124         n->dead = 1;
 125         if (!list_empty(&n->gc_list)) {
 126                 list_del_init(&n->gc_list);
 127                 atomic_dec(&n->tbl->gc_entries);
 128         }
 129 }
 130
 131 static void neigh_update_gc_list(struct neighbour *n)
 132 {
 133         bool on_gc_list, exempt_from_gc;
 134
 135         write_lock_bh(&n->tbl->lock);
 136         write_lock(&n->lock);
 137
 138         /* remove from the gc list if new state is permanent or if neighbor
 139          * is externally learned; otherwise entry should be on the gc list
 140          */
 141         exempt_from_gc = n->nud_state & NUD_PERMANENT ||
 142                          n->flags & NTF_EXT_LEARNED;
 143         on_gc_list = !list_empty(&n->gc_list);
 144
 145         if (exempt_from_gc && on_gc_list) {
 146                 list_del_init(&n->gc_list);
 147                 atomic_dec(&n->tbl->gc_entries);
 148         } else if (!exempt_from_gc && !on_gc_list) {
 149                 /* add entries to the tail; cleaning removes from the front */
 150                 list_add_tail(&n->gc_list, &n->tbl->gc_list);
 151                 atomic_inc(&n->tbl->gc_entries);
 152         }
 153
 154         write_unlock(&n->lock);
 155         write_unlock_bh(&n->tbl->lock);
 156 }
 157
 158 static bool neigh_update_ext_learned(struct neighbour *neigh, u32 flags,
 159                                      int *notify)
 160 {
 161         bool rc = false;
 162         u8 ndm_flags;
 163
 164         if (!(flags & NEIGH_UPDATE_F_ADMIN))
 165                 return rc;
 166
 167         ndm_flags = (flags & NEIGH_UPDATE_F_EXT_LEARNED) ? NTF_EXT_LEARNED : 0;
 168         if ((neigh->flags ^ ndm_flags) & NTF_EXT_LEARNED) {
 169                 if (ndm_flags & NTF_EXT_LEARNED)
 170                         neigh->flags |= NTF_EXT_LEARNED;
 171                 else
 172                         neigh->flags &= ~NTF_EXT_LEARNED;
 173                 rc = true;
 174                 *notify = 1;
 175         }
 176
 177         return rc;
 178 }
 179
 180 static bool neigh_del(struct neighbour *n, struct neighbour __rcu **np,
 181                       struct neigh_table *tbl)
 182 {
 183         bool retval = false;
 184
 185         write_lock(&n->lock);
 186         if (refcount_read(&n->refcnt) == 1) {
 187                 struct neighbour *neigh;
 188
 189                 neigh = rcu_dereference_protected(n->next,
 190                                                   lockdep_is_held(&tbl->lock));
 191                 rcu_assign_pointer(*np, neigh);
 192                 neigh_mark_dead(n);
 193                 retval = true;
 194         }
 195         write_unlock(&n->lock);
 196         if (retval)
 197                 neigh_cleanup_and_release(n);
 198         return retval;
 199 }
 200
 201 bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl)
 202 {
 203         struct neigh_hash_table *nht;
 204         void *pkey = ndel->primary_key;
 205         u32 hash_val;
 206         struct neighbour *n;
 207         struct neighbour __rcu **np;
 208
 209         nht = rcu_dereference_protected(tbl->nht,
 210                                         lockdep_is_held(&tbl->lock));
 211         hash_val = tbl->hash(pkey, ndel->dev, nht->hash_rnd);
 212         hash_val = hash_val >> (32 - nht->hash_shift);
 213
 214         np = &nht->hash_buckets[hash_val];
 215         while ((n = rcu_dereference_protected(*np,
 216                                               lockdep_is_held(&tbl->lock)))) {
 217                 if (n == ndel)
 218                         return neigh_del(n, np, tbl);
 219                 np = &n->next;
 220         }
 221         return false;
 222 }
 223
 224 static int neigh_forced_gc(struct neigh_table *tbl)
 225 {
 226         int max_clean = atomic_read(&tbl->gc_entries) - tbl->gc_thresh2;
 227         unsigned long tref = jiffies - 5 * HZ;
 228         struct neighbour *n, *tmp;
 229         int shrunk = 0;
 230
 231         NEIGH_CACHE_STAT_INC(tbl, forced_gc_runs);
 232
 233         write_lock_bh(&tbl->lock);
 234
 235         list_for_each_entry_safe(n, tmp, &tbl->gc_list, gc_list) {
 236                 if (refcount_read(&n->refcnt) == 1) {
 237                         bool remove = false;
 238
 239                         write_lock(&n->lock);
 240                         if ((n->nud_state == NUD_FAILED) ||
 241                             time_after(tref, n->updated))
 242                                 remove = true;
 243                         write_unlock(&n->lock);
 244
 245                         if (remove && neigh_remove_one(n, tbl))
 246                                 shrunk++;
 247                         if (shrunk >= max_clean)
 248                                 break;
 249                 }
 250         }
 251
 252         tbl->last_flush = jiffies;
 253
 254         write_unlock_bh(&tbl->lock);
 255
 256         return shrunk;
 257 }
 258
 259 static void neigh_add_timer(struct neighbour *n, unsigned long when)
 260 {
 261         neigh_hold(n);
 262         if (unlikely(mod_timer(&n->timer, when))) {
 263                 printk("NEIGH: BUG, double timer add, state is %x\n",
 264                        n->nud_state);
 265                 dump_stack();
 266         }
 267 }
 268
 269 static int neigh_del_timer(struct neighbour *n)
 270 {
 271         if ((n->nud_state & NUD_IN_TIMER) &&
 272             del_timer(&n->timer)) {
 273                 neigh_release(n);
 274                 return 1;
 275         }
 276         return 0;
 277 }
 278
 279 static void pneigh_queue_purge(struct sk_buff_head *list)
 280 {
 281         struct sk_buff *skb;
 282
 283         while ((skb = skb_dequeue(list)) != NULL) {
 284                 dev_put(skb->dev);
 285                 kfree_skb(skb);
 286         }
 287 }
 288
 289 static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev,
 290                             bool skip_perm)
 291 {
 292         int i;
 293         struct neigh_hash_table *nht;
 294
 295         nht = rcu_dereference_protected(tbl->nht,
 296                                         lockdep_is_held(&tbl->lock));
 297
 298         for (i = 0; i < (1 << nht->hash_shift); i++) {
 299                 struct neighbour *n;
 300                 struct neighbour __rcu **np = &nht->hash_buckets[i];
 301
 302                 while ((n = rcu_dereference_protected(*np,
 303                                         lockdep_is_held(&tbl->lock))) != NULL) {
 304                         if (dev && n->dev != dev) {
 305                                 np = &n->next;
 306                                 continue;
 307                         }
 308                         if (skip_perm && n->nud_state & NUD_PERMANENT) {
 309                                 np = &n->next;
 310                                 continue;
 311                         }
 312                         rcu_assign_pointer(*np,
 313                                    rcu_dereference_protected(n->next,
 314                                                 lockdep_is_held(&tbl->lock)));
 315                         write_lock(&n->lock);
 316                         neigh_del_timer(n);
 317                         neigh_mark_dead(n);
 318                         if (refcount_read(&n->refcnt) != 1) {
 319                                 /* The most unpleasant situation.
 320                                    We must destroy neighbour entry,
 321                                    but someone still uses it.
 322
 323                                    The destroy will be delayed until
 324                                    the last user releases us, but
 325                                    we must kill timers etc. and move
 326                                    it to safe state.
 327                                  */
 328                                 __skb_queue_purge(&n->arp_queue);
 329                                 n->arp_queue_len_bytes = 0;
 330                                 n->output = neigh_blackhole;
 331                                 if (n->nud_state & NUD_VALID)
 332                                         n->nud_state = NUD_NOARP;
 333                                 else
 334                                         n->nud_state = NUD_NONE;
 335                                 neigh_dbg(2, "neigh %p is stray\n", n);
 336                         }
 337                         write_unlock(&n->lock);
 338                         neigh_cleanup_and_release(n);
 339                 }
 340         }
 341 }
 342
 343 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev)
 344 {
 345         write_lock_bh(&tbl->lock);
 346         neigh_flush_dev(tbl, dev, false);
 347         write_unlock_bh(&tbl->lock);
 348 }
 349 EXPORT_SYMBOL(neigh_changeaddr);
 350
 351 static int __neigh_ifdown(struct neigh_table *tbl, struct net_device *dev,
 352                           bool skip_perm)
 353 {
 354         write_lock_bh(&tbl->lock);
 355         neigh_flush_dev(tbl, dev, skip_perm);
 356         pneigh_ifdown_and_unlock(tbl, dev);
 357
 358         del_timer_sync(&tbl->proxy_timer);
 359         pneigh_queue_purge(&tbl->proxy_queue);
 360         return 0;
 361 }
 362
 363 int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev)
 364 {
 365         __neigh_ifdown(tbl, dev, true);
 366         return 0;
 367 }
 368 EXPORT_SYMBOL(neigh_carrier_down);
 369
 370 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 371 {
 372         __neigh_ifdown(tbl, dev, false);
 373         return 0;
 374 }
 375 EXPORT_SYMBOL(neigh_ifdown);
 376
 377 static struct neighbour *neigh_alloc(struct neigh_table *tbl,
 378                                      struct net_device *dev,
 379                                      bool exempt_from_gc)
 380 {
 381         struct neighbour *n = NULL;
 382         unsigned long now = jiffies;
 383         int entries;
 384
 385         if (exempt_from_gc)
 386                 goto do_alloc;
 387
 388         entries = atomic_inc_return(&tbl->gc_entries) - 1;
 389         if (entries >= tbl->gc_thresh3 ||
 390             (entries >= tbl->gc_thresh2 &&
 391              time_after(now, tbl->last_flush + 5 * HZ))) {
 392                 if (!neigh_forced_gc(tbl) &&
 393                     entries >= tbl->gc_thresh3) {
 394                         net_info_ratelimited("%s: neighbor table overflow!\n",
 395                                              tbl->id);
 396                         NEIGH_CACHE_STAT_INC(tbl, table_fulls);
 397                         goto out_entries;
 398                 }
 399         }
 400
 401 do_alloc:
 402         n = kzalloc(tbl->entry_size + dev->neigh_priv_len, GFP_ATOMIC);
 403         if (!n)
 404                 goto out_entries;
 405
 406         __skb_queue_head_init(&n->arp_queue);
 407         rwlock_init(&n->lock);
 408         seqlock_init(&n->ha_lock);
 409         n->updated        = n->used = now;
 410         n->nud_state      = NUD_NONE;
 411         n->output         = neigh_blackhole;
 412         seqlock_init(&n->hh.hh_lock);
 413         n->parms          = neigh_parms_clone(&tbl->parms);
 414         timer_setup(&n->timer, neigh_timer_handler, 0);
 415
 416         NEIGH_CACHE_STAT_INC(tbl, allocs);
 417         n->tbl            = tbl;
 418         refcount_set(&n->refcnt, 1);
 419         n->dead           = 1;
 420         INIT_LIST_HEAD(&n->gc_list);
 421
 422         atomic_inc(&tbl->entries);
 423 out:
 424         return n;
 425
 426 out_entries:
 427         if (!exempt_from_gc)
 428                 atomic_dec(&tbl->gc_entries);
 429         goto out;
 430 }
 431
 432 static void neigh_get_hash_rnd(u32 *x)
 433 {
 434         *x = get_random_u32() | 1;
 435 }
 436
 437 static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift)
 438 {
 439         size_t size = (1 << shift) * sizeof(struct neighbour *);
 440         struct neigh_hash_table *ret;
 441         struct neighbour __rcu **buckets;
 442         int i;
 443
 444         ret = kmalloc(sizeof(*ret), GFP_ATOMIC);
 445         if (!ret)
 446                 return NULL;
 447         if (size <= PAGE_SIZE) {
 448                 buckets = kzalloc(size, GFP_ATOMIC);
 449         } else {
 450                 buckets = (struct neighbour __rcu **)
 451                           __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
 452                                            get_order(size));
 453                 kmemleak_alloc(buckets, size, 1, GFP_ATOMIC);
 454         }
 455         if (!buckets) {
 456                 kfree(ret);
 457                 return NULL;
 458         }
 459         ret->hash_buckets = buckets;
 460         ret->hash_shift = shift;
 461         for (i = 0; i < NEIGH_NUM_HASH_RND; i++)
 462                 neigh_get_hash_rnd(&ret->hash_rnd[i]);
 463         return ret;
 464 }
 465
 466 static void neigh_hash_free_rcu(struct rcu_head *head)
 467 {
 468         struct neigh_hash_table *nht = container_of(head,
 469                                                     struct neigh_hash_table,
 470                                                     rcu);
 471         size_t size = (1 << nht->hash_shift) * sizeof(struct neighbour *);
 472         struct neighbour __rcu **buckets = nht->hash_buckets;
 473
 474         if (size <= PAGE_SIZE) {
 475                 kfree(buckets);
 476         } else {
 477                 kmemleak_free(buckets);
 478                 free_pages((unsigned long)buckets, get_order(size));
 479         }
 480         kfree(nht);
 481 }
 482
 483 static struct neigh_hash_table *neigh_hash_grow(struct neigh_table *tbl,
 484                                                 unsigned long new_shift)
 485 {
 486         unsigned int i, hash;
 487         struct neigh_hash_table *new_nht, *old_nht;
 488
 489         NEIGH_CACHE_STAT_INC(tbl, hash_grows);
 490
 491         old_nht = rcu_dereference_protected(tbl->nht,
 492                                             lockdep_is_held(&tbl->lock));
 493         new_nht = neigh_hash_alloc(new_shift);
 494         if (!new_nht)
 495                 return old_nht;
 496
 497         for (i = 0; i < (1 << old_nht->hash_shift); i++) {
 498                 struct neighbour *n, *next;
 499
 500                 for (n = rcu_dereference_protected(old_nht->hash_buckets[i],
 501                                                    lockdep_is_held(&tbl->lock));
 502                      n != NULL;
 503                      n = next) {
 504                         hash = tbl->hash(n->primary_key, n->dev,
 505                                          new_nht->hash_rnd);
 506
 507                         hash >>= (32 - new_nht->hash_shift);
 508                         next = rcu_dereference_protected(n->next,
 509                                                 lockdep_is_held(&tbl->lock));
 510
 511                         rcu_assign_pointer(n->next,
 512                                            rcu_dereference_protected(
 513                                                 new_nht->hash_buckets[hash],
 514                                                 lockdep_is_held(&tbl->lock)));
 515                         rcu_assign_pointer(new_nht->hash_buckets[hash], n);
 516                 }
 517         }
 518
 519         rcu_assign_pointer(tbl->nht, new_nht);
 520         call_rcu(&old_nht->rcu, neigh_hash_free_rcu);
 521         return new_nht;
 522 }
 523
 524 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
 525                                struct net_device *dev)
 526 {
 527         struct neighbour *n;
 528
 529         NEIGH_CACHE_STAT_INC(tbl, lookups);
 530
 531         rcu_read_lock_bh();
 532         n = __neigh_lookup_noref(tbl, pkey, dev);
 533         if (n) {
 534                 if (!refcount_inc_not_zero(&n->refcnt))
 535                         n = NULL;
 536                 NEIGH_CACHE_STAT_INC(tbl, hits);
 537         }
 538
 539         rcu_read_unlock_bh();
 540         return n;
 541 }
 542 EXPORT_SYMBOL(neigh_lookup);
 543
 544 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
 545                                      const void *pkey)
 546 {
 547         struct neighbour *n;
 548         unsigned int key_len = tbl->key_len;
 549         u32 hash_val;
 550         struct neigh_hash_table *nht;
 551
 552         NEIGH_CACHE_STAT_INC(tbl, lookups);
 553
 554         rcu_read_lock_bh();
 555         nht = rcu_dereference_bh(tbl->nht);
 556         hash_val = tbl->hash(pkey, NULL, nht->hash_rnd) >> (32 - nht->hash_shift);
 557
 558         for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
 559              n != NULL;
 560              n = rcu_dereference_bh(n->next)) {
 561                 if (!memcmp(n->primary_key, pkey, key_len) &&
 562                     net_eq(dev_net(n->dev), net)) {
 563                         if (!refcount_inc_not_zero(&n->refcnt))
 564                                 n = NULL;
 565                         NEIGH_CACHE_STAT_INC(tbl, hits);
 566                         break;
 567                 }
 568         }
 569
 570         rcu_read_unlock_bh();
 571         return n;
 572 }
 573 EXPORT_SYMBOL(neigh_lookup_nodev);
 574
 575 static struct neighbour *___neigh_create(struct neigh_table *tbl,
 576                                          const void *pkey,
 577                                          struct net_device *dev,
 578                                          bool exempt_from_gc, bool want_ref)
 579 {
 580         struct neighbour *n1, *rc, *n = neigh_alloc(tbl, dev, exempt_from_gc);
 581         u32 hash_val;
 582         unsigned int key_len = tbl->key_len;
 583         int error;
 584         struct neigh_hash_table *nht;
 585
 586         trace_neigh_create(tbl, dev, pkey, n, exempt_from_gc);
 587
 588         if (!n) {
 589                 rc = ERR_PTR(-ENOBUFS);
 590                 goto out;
 591         }
 592
 593         memcpy(n->primary_key, pkey, key_len);
 594         n->dev = dev;
 595         dev_hold(dev);
 596
 597         /* Protocol specific setup. */
 598         if (tbl->constructor && (error = tbl->constructor(n)) < 0) {
 599                 rc = ERR_PTR(error);
 600                 goto out_neigh_release;
 601         }
 602
 603         if (dev->netdev_ops->ndo_neigh_construct) {
 604                 error = dev->netdev_ops->ndo_neigh_construct(dev, n);
 605                 if (error < 0) {
 606                         rc = ERR_PTR(error);
 607                         goto out_neigh_release;
 608                 }
 609         }
 610
 611         /* Device specific setup. */
 612         if (n->parms->neigh_setup &&
 613             (error = n->parms->neigh_setup(n)) < 0) {
 614                 rc = ERR_PTR(error);
 615                 goto out_neigh_release;
 616         }
 617
 618         n->confirmed = jiffies - (NEIGH_VAR(n->parms, BASE_REACHABLE_TIME) << 1);
 619
 620         write_lock_bh(&tbl->lock);
 621         nht = rcu_dereference_protected(tbl->nht,
 622                                         lockdep_is_held(&tbl->lock));
 623
 624         if (atomic_read(&tbl->entries) > (1 << nht->hash_shift))
 625                 nht = neigh_hash_grow(tbl, nht->hash_shift + 1);
 626
 627         hash_val = tbl->hash(n->primary_key, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
 628
 629         if (n->parms->dead) {
 630                 rc = ERR_PTR(-EINVAL);
 631                 goto out_tbl_unlock;
 632         }
 633
 634         for (n1 = rcu_dereference_protected(nht->hash_buckets[hash_val],
 635                                             lockdep_is_held(&tbl->lock));
 636              n1 != NULL;
 637              n1 = rcu_dereference_protected(n1->next,
 638                         lockdep_is_held(&tbl->lock))) {
 639                 if (dev == n1->dev && !memcmp(n1->primary_key, n->primary_key, key_len)) {
 640                         if (want_ref)
 641                                 neigh_hold(n1);
 642                         rc = n1;
 643                         goto out_tbl_unlock;
 644                 }
 645         }
 646
 647         n->dead = 0;
 648         if (!exempt_from_gc)
 649                 list_add_tail(&n->gc_list, &n->tbl->gc_list);
 650
 651         if (want_ref)
 652                 neigh_hold(n);
 653         rcu_assign_pointer(n->next,
 654                            rcu_dereference_protected(nht->hash_buckets[hash_val],
 655                                                      lockdep_is_held(&tbl->lock)));
 656         rcu_assign_pointer(nht->hash_buckets[hash_val], n);
 657         write_unlock_bh(&tbl->lock);
 658         neigh_dbg(2, "neigh %p is created\n", n);
 659         rc = n;
 660 out:
 661         return rc;
 662 out_tbl_unlock:
 663         write_unlock_bh(&tbl->lock);
 664 out_neigh_release:
 665         if (!exempt_from_gc)
 666                 atomic_dec(&tbl->gc_entries);
 667         neigh_release(n);
 668         goto out;
 669 }
 670
 671 struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
 672                                  struct net_device *dev, bool want_ref)
 673 {
 674         return ___neigh_create(tbl, pkey, dev, false, want_ref);
 675 }
 676 EXPORT_SYMBOL(__neigh_create);
 677
 678 static u32 pneigh_hash(const void *pkey, unsigned int key_len)
 679 {
 680         u32 hash_val = *(u32 *)(pkey + key_len - 4);
 681         hash_val ^= (hash_val >> 16);
 682         hash_val ^= hash_val >> 8;
 683         hash_val ^= hash_val >> 4;
 684         hash_val &= PNEIGH_HASHMASK;
 685         return hash_val;
 686 }
 687
 688 static struct pneigh_entry *__pneigh_lookup_1(struct pneigh_entry *n,
 689                                               struct net *net,
 690                                               const void *pkey,
 691                                               unsigned int key_len,
 692                                               struct net_device *dev)
 693 {
 694         while (n) {
 695                 if (!memcmp(n->key, pkey, key_len) &&
 696                     net_eq(pneigh_net(n), net) &&
 697                     (n->dev == dev || !n->dev))
 698                         return n;
 699                 n = n->next;
 700         }
 701         return NULL;
 702 }
 703
 704 struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl,
 705                 struct net *net, const void *pkey, struct net_device *dev)
 706 {
 707         unsigned int key_len = tbl->key_len;
 708         u32 hash_val = pneigh_hash(pkey, key_len);
 709
 710         return __pneigh_lookup_1(tbl->phash_buckets[hash_val],
 711                                  net, pkey, key_len, dev);
 712 }
 713 EXPORT_SYMBOL_GPL(__pneigh_lookup);
 714
 715 struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl,
 716                                     struct net *net, const void *pkey,
 717                                     struct net_device *dev, int creat)
 718 {
 719         struct pneigh_entry *n;
 720         unsigned int key_len = tbl->key_len;
 721         u32 hash_val = pneigh_hash(pkey, key_len);
 722
 723         read_lock_bh(&tbl->lock);
 724         n = __pneigh_lookup_1(tbl->phash_buckets[hash_val],
 725                               net, pkey, key_len, dev);
 726         read_unlock_bh(&tbl->lock);
 727
 728         if (n || !creat)
 729                 goto out;
 730
 731         ASSERT_RTNL();
 732
 733         n = kmalloc(sizeof(*n) + key_len, GFP_KERNEL);
 734         if (!n)
 735                 goto out;
 736
 737         n->protocol = 0;
 738         write_pnet(&n->net, net);
 739         memcpy(n->key, pkey, key_len);
 740         n->dev = dev;
 741         if (dev)
 742                 dev_hold(dev);
 743
 744         if (tbl->pconstructor && tbl->pconstructor(n)) {
 745                 if (dev)
 746                         dev_put(dev);
 747                 kfree(n);
 748                 n = NULL;
 749                 goto out;
 750         }
 751
 752         write_lock_bh(&tbl->lock);
 753         n->next = tbl->phash_buckets[hash_val];
 754         tbl->phash_buckets[hash_val] = n;
 755         write_unlock_bh(&tbl->lock);
 756 out:
 757         return n;
 758 }
 759 EXPORT_SYMBOL(pneigh_lookup);
 760
 761
 762 int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *pkey,
 763                   struct net_device *dev)
 764 {
 765         struct pneigh_entry *n, **np;
 766         unsigned int key_len = tbl->key_len;
 767         u32 hash_val = pneigh_hash(pkey, key_len);
 768
 769         write_lock_bh(&tbl->lock);
 770         for (np = &tbl->phash_buckets[hash_val]; (n = *np) != NULL;
 771              np = &n->next) {
 772                 if (!memcmp(n->key, pkey, key_len) && n->dev == dev &&
 773                     net_eq(pneigh_net(n), net)) {
 774                         *np = n->next;
 775                         write_unlock_bh(&tbl->lock);
 776                         if (tbl->pdestructor)
 777                                 tbl->pdestructor(n);
 778                         if (n->dev)
 779                                 dev_put(n->dev);
 780                         kfree(n);
 781                         return 0;
 782                 }
 783         }
 784         write_unlock_bh(&tbl->lock);
 785         return -ENOENT;
 786 }
 787
 788 static int pneigh_ifdown_and_unlock(struct neigh_table *tbl,
 789                                     struct net_device *dev)
 790 {
 791         struct pneigh_entry *n, **np, *freelist = NULL;
 792         u32 h;
 793
 794         for (h = 0; h <= PNEIGH_HASHMASK; h++) {
 795                 np = &tbl->phash_buckets[h];
 796                 while ((n = *np) != NULL) {
 797                         if (!dev || n->dev == dev) {
 798                                 *np = n->next;
 799                                 n->next = freelist;
 800                                 freelist = n;
 801                                 continue;
 802                         }
 803                         np = &n->next;
 804                 }
 805         }
 806         write_unlock_bh(&tbl->lock);
 807         while ((n = freelist)) {
 808                 freelist = n->next;
 809                 n->next = NULL;
 810                 if (tbl->pdestructor)
 811                         tbl->pdestructor(n);
 812                 if (n->dev)
 813                         dev_put(n->dev);
 814                 kfree(n);
 815         }
 816         return -ENOENT;
 817 }
 818
 819 static void neigh_parms_destroy(struct neigh_parms *parms);
 820
 821 static inline void neigh_parms_put(struct neigh_parms *parms)
 822 {
 823         if (refcount_dec_and_test(&parms->refcnt))
 824                 neigh_parms_destroy(parms);
 825 }
 826
 827 /*
 828  *      neighbour must already be out of the table;
 829  *
 830  */
 831 void neigh_destroy(struct neighbour *neigh)
 832 {
 833         struct net_device *dev = neigh->dev;
 834
 835         NEIGH_CACHE_STAT_INC(neigh->tbl, destroys);
 836
 837         if (!neigh->dead) {
 838                 pr_warn("Destroying alive neighbour %p\n", neigh);
 839                 dump_stack();
 840                 return;
 841         }
 842
 843         if (neigh_del_timer(neigh))
 844                 pr_warn("Impossible event\n");
 845
 846         write_lock_bh(&neigh->lock);
 847         __skb_queue_purge(&neigh->arp_queue);
 848         write_unlock_bh(&neigh->lock);
 849         neigh->arp_queue_len_bytes = 0;
 850
 851         if (dev->netdev_ops->ndo_neigh_destroy)
 852                 dev->netdev_ops->ndo_neigh_destroy(dev, neigh);
 853
 854         dev_put(dev);
 855         neigh_parms_put(neigh->parms);
 856
 857         neigh_dbg(2, "neigh %p is destroyed\n", neigh);
 858
 859         atomic_dec(&neigh->tbl->entries);
 860         kfree_rcu(neigh, rcu);
 861 }
 862 EXPORT_SYMBOL(neigh_destroy);
 863
 864 /* Neighbour state is suspicious;
 865    disable fast path.
 866
 867    Called with write_locked neigh.
 868  */
 869 static void neigh_suspect(struct neighbour *neigh)
 870 {
 871         neigh_dbg(2, "neigh %p is suspected\n", neigh);
 872
 873         neigh->output = neigh->ops->output;
 874 }
 875
 876 /* Neighbour state is OK;
 877    enable fast path.
 878
 879    Called with write_locked neigh.
 880  */
 881 static void neigh_connect(struct neighbour *neigh)
 882 {
 883         neigh_dbg(2, "neigh %p is connected\n", neigh);
 884
 885         neigh->output = neigh->ops->connected_output;
 886 }
 887
 888 static void neigh_periodic_work(struct work_struct *work)
 889 {
 890         struct neigh_table *tbl = container_of(work, struct neigh_table, gc_work.work);
 891         struct neighbour *n;
 892         struct neighbour __rcu **np;
 893         unsigned int i;
 894         struct neigh_hash_table *nht;
 895
 896         NEIGH_CACHE_STAT_INC(tbl, periodic_gc_runs);
 897
 898         write_lock_bh(&tbl->lock);
 899         nht = rcu_dereference_protected(tbl->nht,
 900                                         lockdep_is_held(&tbl->lock));
 901
 902         /*
 903          *      periodically recompute ReachableTime from random function
 904          */
 905
 906         if (time_after(jiffies, tbl->last_rand + 300 * HZ)) {
 907                 struct neigh_parms *p;
 908                 tbl->last_rand = jiffies;
 909                 list_for_each_entry(p, &tbl->parms_list, list)
 910                         p->reachable_time =
 911                                 neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
 912         }
 913
 914         if (atomic_read(&tbl->entries) < tbl->gc_thresh1)
 915                 goto out;
 916
 917         for (i = 0 ; i < (1 << nht->hash_shift); i++) {
 918                 np = &nht->hash_buckets[i];
 919
 920                 while ((n = rcu_dereference_protected(*np,
 921                                 lockdep_is_held(&tbl->lock))) != NULL) {
 922                         unsigned int state;
 923
 924                         write_lock(&n->lock);
 925
 926                         state = n->nud_state;
 927                         if ((state & (NUD_PERMANENT | NUD_IN_TIMER)) ||
 928                             (n->flags & NTF_EXT_LEARNED)) {
 929                                 write_unlock(&n->lock);
 930                                 goto next_elt;
 931                         }
 932
 933                         if (time_before(n->used, n->confirmed))
 934                                 n->used = n->confirmed;
 935
 936                         if (refcount_read(&n->refcnt) == 1 &&
 937                             (state == NUD_FAILED ||
 938                              time_after(jiffies, n->used + NEIGH_VAR(n->parms, GC_STALETIME)))) {
 939                                 *np = n->next;
 940                                 neigh_mark_dead(n);
 941                                 write_unlock(&n->lock);
 942                                 neigh_cleanup_and_release(n);
 943                                 continue;
 944                         }
 945                         write_unlock(&n->lock);
 946
 947 next_elt:
 948                         np = &n->next;
 949                 }
 950                 /*
 951                  * It's fine to release lock here, even if hash table
 952                  * grows while we are preempted.
 953                  */
 954                 write_unlock_bh(&tbl->lock);
 955                 cond_resched();
 956                 write_lock_bh(&tbl->lock);
 957                 nht = rcu_dereference_protected(tbl->nht,
 958                                                 lockdep_is_held(&tbl->lock));
 959         }
 960 out:
 961         /* Cycle through all hash buckets every BASE_REACHABLE_TIME/2 ticks.
 962          * ARP entry timeouts range from 1/2 BASE_REACHABLE_TIME to 3/2
 963          * BASE_REACHABLE_TIME.
 964          */
 965         queue_delayed_work(system_power_efficient_wq, &tbl->gc_work,
 966                               NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME) >> 1);
 967         write_unlock_bh(&tbl->lock);
 968 }
 969
 970 static __inline__ int neigh_max_probes(struct neighbour *n)
 971 {
 972         struct neigh_parms *p = n->parms;
 973         return NEIGH_VAR(p, UCAST_PROBES) + NEIGH_VAR(p, APP_PROBES) +
 974                (n->nud_state & NUD_PROBE ? NEIGH_VAR(p, MCAST_REPROBES) :
 975                 NEIGH_VAR(p, MCAST_PROBES));
 976 }
 977
 978 static void neigh_invalidate(struct neighbour *neigh)
 979         __releases(neigh->lock)
 980         __acquires(neigh->lock)
 981 {
 982         struct sk_buff *skb;
 983
 984         NEIGH_CACHE_STAT_INC(neigh->tbl, res_failed);
 985         neigh_dbg(2, "neigh %p is failed\n", neigh);
 986         neigh->updated = jiffies;
 987
 988         /* It is very thin place. report_unreachable is very complicated
 989            routine. Particularly, it can hit the same neighbour entry!
 990
 991            So that, we try to be accurate and avoid dead loop. --ANK
 992          */
 993         while (neigh->nud_state == NUD_FAILED &&
 994                (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
 995                 write_unlock(&neigh->lock);
 996                 neigh->ops->error_report(neigh, skb);
 997                 write_lock(&neigh->lock);
 998         }
 999         __skb_queue_purge(&neigh->arp_queue);
1000         neigh->arp_queue_len_bytes = 0;
1001 }
1002
1003 static void neigh_probe(struct neighbour *neigh)
1004         __releases(neigh->lock)
1005 {
1006         struct sk_buff *skb = skb_peek_tail(&neigh->arp_queue);
1007         /* keep skb alive even if arp_queue overflows */
1008         if (skb)
1009                 skb = skb_clone(skb, GFP_ATOMIC);
1010         write_unlock(&neigh->lock);
1011         if (neigh->ops->solicit)
1012                 neigh->ops->solicit(neigh, skb);
1013         atomic_inc(&neigh->probes);
1014         consume_skb(skb);
1015 }
1016
1017 /* Called when a timer expires for a neighbour entry. */
1018
1019 static void neigh_timer_handler(struct timer_list *t)
1020 {
1021         unsigned long now, next;
1022         struct neighbour *neigh = from_timer(neigh, t, timer);
1023         unsigned int state;
1024         int notify = 0;
1025
1026         write_lock(&neigh->lock);
1027
1028         state = neigh->nud_state;
1029         now = jiffies;
1030         next = now + HZ;
1031
1032         if (!(state & NUD_IN_TIMER))
1033                 goto out;
1034
1035         if (state & NUD_REACHABLE) {
1036                 if (time_before_eq(now,
1037                                    neigh->confirmed + neigh->parms->reachable_time)) {
1038                         neigh_dbg(2, "neigh %p is still alive\n", neigh);
1039                         next = neigh->confirmed + neigh->parms->reachable_time;
1040                 } else if (time_before_eq(now,
1041                                           neigh->used +
1042                                           NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME))) {
1043                         neigh_dbg(2, "neigh %p is delayed\n", neigh);
1044                         neigh->nud_state = NUD_DELAY;
1045                         neigh->updated = jiffies;
1046                         neigh_suspect(neigh);
1047                         next = now + NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME);
1048                 } else {
1049                         neigh_dbg(2, "neigh %p is suspected\n", neigh);
1050                         neigh->nud_state = NUD_STALE;
1051                         neigh->updated = jiffies;
1052                         neigh_suspect(neigh);
1053                         notify = 1;
1054                 }
1055         } else if (state & NUD_DELAY) {
1056                 if (time_before_eq(now,
1057                                    neigh->confirmed +
1058                                    NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME))) {
1059                         neigh_dbg(2, "neigh %p is now reachable\n", neigh);
1060                         neigh->nud_state = NUD_REACHABLE;
1061                         neigh->updated = jiffies;
1062                         neigh_connect(neigh);
1063                         notify = 1;
1064                         next = neigh->confirmed + neigh->parms->reachable_time;
1065                 } else {
1066                         neigh_dbg(2, "neigh %p is probed\n", neigh);
1067                         neigh->nud_state = NUD_PROBE;
1068                         neigh->updated = jiffies;
1069                         atomic_set(&neigh->probes, 0);
1070                         notify = 1;
1071                         next = now + NEIGH_VAR(neigh->parms, RETRANS_TIME);
1072                 }
1073         } else {
1074                 /* NUD_PROBE|NUD_INCOMPLETE */
1075                 next = now + NEIGH_VAR(neigh->parms, RETRANS_TIME);
1076         }
1077
1078         if ((neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) &&
1079             atomic_read(&neigh->probes) >= neigh_max_probes(neigh)) {
1080                 neigh->nud_state = NUD_FAILED;
1081                 notify = 1;
1082                 neigh_invalidate(neigh);
1083                 goto out;
1084         }
1085
1086         if (neigh->nud_state & NUD_IN_TIMER) {
1087                 if (time_before(next, jiffies + HZ/2))
1088                         next = jiffies + HZ/2;
1089                 if (!mod_timer(&neigh->timer, next))
1090                         neigh_hold(neigh);
1091         }
1092         if (neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) {
1093                 neigh_probe(neigh);
1094         } else {
1095 out:
1096                 write_unlock(&neigh->lock);
1097         }
1098
1099         if (notify)
1100                 neigh_update_notify(neigh, 0);
1101
1102         trace_neigh_timer_handler(neigh, 0);
1103
1104         neigh_release(neigh);
1105 }
1106
1107 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
1108 {
1109         int rc;
1110         bool immediate_probe = false;
1111
1112         write_lock_bh(&neigh->lock);
1113
1114         rc = 0;
1115         if (neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE))
1116                 goto out_unlock_bh;
1117         if (neigh->dead)
1118                 goto out_dead;
1119
1120         if (!(neigh->nud_state & (NUD_STALE | NUD_INCOMPLETE))) {
1121                 if (NEIGH_VAR(neigh->parms, MCAST_PROBES) +
1122                     NEIGH_VAR(neigh->parms, APP_PROBES)) {
1123                         unsigned long next, now = jiffies;
1124
1125                         atomic_set(&neigh->probes,
1126                                    NEIGH_VAR(neigh->parms, UCAST_PROBES));
1127                         neigh_del_timer(neigh);
1128                         neigh->nud_state     = NUD_INCOMPLETE;
1129                         neigh->updated = now;
1130                         next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),
1131                                          HZ/2);
1132                         neigh_add_timer(neigh, next);
1133                         immediate_probe = true;
1134                 } else {
1135                         neigh->nud_state = NUD_FAILED;
1136                         neigh->updated = jiffies;
1137                         write_unlock_bh(&neigh->lock);
1138
1139                         kfree_skb(skb);
1140                         return 1;
1141                 }
1142         } else if (neigh->nud_state & NUD_STALE) {
1143                 neigh_dbg(2, "neigh %p is delayed\n", neigh);
1144                 neigh_del_timer(neigh);
1145                 neigh->nud_state = NUD_DELAY;
1146                 neigh->updated = jiffies;
1147                 neigh_add_timer(neigh, jiffies +
1148                                 NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME));
1149         }
1150
1151         if (neigh->nud_state == NUD_INCOMPLETE) {
1152                 if (skb) {
1153                         while (neigh->arp_queue_len_bytes + skb->truesize >
1154                                NEIGH_VAR(neigh->parms, QUEUE_LEN_BYTES)) {
1155                                 struct sk_buff *buff;
1156
1157                                 buff = __skb_dequeue(&neigh->arp_queue);
1158                                 if (!buff)
1159                                         break;
1160                                 neigh->arp_queue_len_bytes -= buff->truesize;
1161                                 kfree_skb(buff);
1162                                 NEIGH_CACHE_STAT_INC(neigh->tbl, unres_discards);
1163                         }
1164                         skb_dst_force(skb);
1165                         __skb_queue_tail(&neigh->arp_queue, skb);
1166                         neigh->arp_queue_len_bytes += skb->truesize;
1167                 }
1168                 rc = 1;
1169         }
1170 out_unlock_bh:
1171         if (immediate_probe)
1172                 neigh_probe(neigh);
1173         else
1174                 write_unlock(&neigh->lock);
1175         local_bh_enable();
1176         trace_neigh_event_send_done(neigh, rc);
1177         return rc;
1178
1179 out_dead:
1180         if (neigh->nud_state & NUD_STALE)
1181                 goto out_unlock_bh;
1182         write_unlock_bh(&neigh->lock);
1183         kfree_skb(skb);
1184         trace_neigh_event_send_dead(neigh, 1);
1185         return 1;
1186 }
1187 EXPORT_SYMBOL(__neigh_event_send);
1188
1189 static void neigh_update_hhs(struct neighbour *neigh)
1190 {
1191         struct hh_cache *hh;
1192         void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *)
1193                 = NULL;
1194
1195         if (neigh->dev->header_ops)
1196                 update = neigh->dev->header_ops->cache_update;
1197
1198         if (update) {
1199                 hh = &neigh->hh;
1200                 if (hh->hh_len) {
1201                         write_seqlock_bh(&hh->hh_lock);
1202                         update(hh, neigh->dev, neigh->ha);
1203                         write_sequnlock_bh(&hh->hh_lock);
1204                 }
1205         }
1206 }
1207
1208
1209
1210 /* Generic update routine.
1211    -- lladdr is new lladdr or NULL, if it is not supplied.
1212    -- new    is new state.
1213    -- flags
1214         NEIGH_UPDATE_F_OVERRIDE allows to override existing lladdr,
1215                                 if it is different.
1216         NEIGH_UPDATE_F_WEAK_OVERRIDE will suspect existing "connected"
1217                                 lladdr instead of overriding it
1218                                 if it is different.
1219         NEIGH_UPDATE_F_ADMIN    means that the change is administrative.
1220
1221         NEIGH_UPDATE_F_OVERRIDE_ISROUTER allows to override existing
1222                                 NTF_ROUTER flag.
1223         NEIGH_UPDATE_F_ISROUTER indicates if the neighbour is known as
1224                                 a router.
1225
1226    Caller MUST hold reference count on the entry.
1227  */
1228
1229 static int __neigh_update(struct neighbour *neigh, const u8 *lladdr,
1230                           u8 new, u32 flags, u32 nlmsg_pid,
1231                           struct netlink_ext_ack *extack)
1232 {
1233         bool ext_learn_change = false;
1234         u8 old;
1235         int err;
1236         int notify = 0;
1237         struct net_device *dev;
1238         int update_isrouter = 0;
1239
1240         trace_neigh_update(neigh, lladdr, new, flags, nlmsg_pid);
1241
1242         write_lock_bh(&neigh->lock);
1243
1244         dev    = neigh->dev;
1245         old    = neigh->nud_state;
1246         err    = -EPERM;
1247
1248         if (!(flags & NEIGH_UPDATE_F_ADMIN) &&
1249             (old & (NUD_NOARP | NUD_PERMANENT)))
1250                 goto out;
1251         if (neigh->dead) {
1252                 NL_SET_ERR_MSG(extack, "Neighbor entry is now dead");
1253                 goto out;
1254         }
1255
1256         ext_learn_change = neigh_update_ext_learned(neigh, flags, &notify);
1257
1258         if (!(new & NUD_VALID)) {
1259                 neigh_del_timer(neigh);
1260                 if (old & NUD_CONNECTED)
1261                         neigh_suspect(neigh);
1262                 neigh->nud_state = new;
1263                 err = 0;
1264                 notify = old & NUD_VALID;
1265                 if ((old & (NUD_INCOMPLETE | NUD_PROBE)) &&
1266                     (new & NUD_FAILED)) {
1267                         neigh_invalidate(neigh);
1268                         notify = 1;
1269                 }
1270                 goto out;
1271         }
1272
1273         /* Compare new lladdr with cached one */
1274         if (!dev->addr_len) {
1275                 /* First case: device needs no address. */
1276                 lladdr = neigh->ha;
1277         } else if (lladdr) {
1278                 /* The second case: if something is already cached
1279                    and a new address is proposed:
1280                    - compare new & old
1281                    - if they are different, check override flag
1282                  */
1283                 if ((old & NUD_VALID) &&
1284                     !memcmp(lladdr, neigh->ha, dev->addr_len))
1285                         lladdr = neigh->ha;
1286         } else {
1287                 /* No address is supplied; if we know something,
1288                    use it, otherwise discard the request.
1289                  */
1290                 err = -EINVAL;
1291                 if (!(old & NUD_VALID)) {
1292                         NL_SET_ERR_MSG(extack, "No link layer address given");
1293                         goto out;
1294                 }
1295                 lladdr = neigh->ha;
1296         }
1297
1298         /* Update confirmed timestamp for neighbour entry after we
1299          * received ARP packet even if it doesn't change IP to MAC binding.
1300          */
1301         if (new & NUD_CONNECTED)
1302                 neigh->confirmed = jiffies;
1303
1304         /* If entry was valid and address is not changed,
1305            do not change entry state, if new one is STALE.
1306          */
1307         err = 0;
1308         update_isrouter = flags & NEIGH_UPDATE_F_OVERRIDE_ISROUTER;
1309         if (old & NUD_VALID) {
1310                 if (lladdr != neigh->ha && !(flags & NEIGH_UPDATE_F_OVERRIDE)) {
1311                         update_isrouter = 0;
1312                         if ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) &&
1313                             (old & NUD_CONNECTED)) {
1314                                 lladdr = neigh->ha;
1315                                 new = NUD_STALE;
1316                         } else
1317                                 goto out;
1318                 } else {
1319                         if (lladdr == neigh->ha && new == NUD_STALE &&
1320                             !(flags & NEIGH_UPDATE_F_ADMIN))
1321                                 new = old;
1322                 }
1323         }
1324
1325         /* Update timestamp only once we know we will make a change to the
1326          * neighbour entry. Otherwise we risk to move the locktime window with
1327          * noop updates and ignore relevant ARP updates.
1328          */
1329         if (new != old || lladdr != neigh->ha)
1330                 neigh->updated = jiffies;
1331
1332         if (new != old) {
1333                 neigh_del_timer(neigh);
1334                 if (new & NUD_PROBE)
1335                         atomic_set(&neigh->probes, 0);
1336                 if (new & NUD_IN_TIMER)
1337                         neigh_add_timer(neigh, (jiffies +
1338                                                 ((new & NUD_REACHABLE) ?
1339                                                  neigh->parms->reachable_time :
1340                                                  0)));
1341                 neigh->nud_state = new;
1342                 notify = 1;
1343         }
1344
1345         if (lladdr != neigh->ha) {
1346                 write_seqlock(&neigh->ha_lock);
1347                 memcpy(&neigh->ha, lladdr, dev->addr_len);
1348                 write_sequnlock(&neigh->ha_lock);
1349                 neigh_update_hhs(neigh);
1350                 if (!(new & NUD_CONNECTED))
1351                         neigh->confirmed = jiffies -
1352                                       (NEIGH_VAR(neigh->parms, BASE_REACHABLE_TIME) << 1);
1353                 notify = 1;
1354         }
1355         if (new == old)
1356                 goto out;
1357         if (new & NUD_CONNECTED)
1358                 neigh_connect(neigh);
1359         else
1360                 neigh_suspect(neigh);
1361         if (!(old & NUD_VALID)) {
1362                 struct sk_buff *skb;
1363
1364                 /* Again: avoid dead loop if something went wrong */
1365
1366                 while (neigh->nud_state & NUD_VALID &&
1367                        (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
1368                         struct dst_entry *dst = skb_dst(skb);
1369                         struct neighbour *n2, *n1 = neigh;
1370                         write_unlock_bh(&neigh->lock);
1371
1372                         rcu_read_lock();
1373
1374                         /* Why not just use 'neigh' as-is?  The problem is that
1375                          * things such as shaper, eql, and sch_teql can end up
1376                          * using alternative, different, neigh objects to output
1377                          * the packet in the output path.  So what we need to do
1378                          * here is re-lookup the top-level neigh in the path so
1379                          * we can reinject the packet there.
1380                          */
1381                         n2 = NULL;
1382                         if (dst) {
1383                                 n2 = dst_neigh_lookup_skb(dst, skb);
1384                                 if (n2)
1385                                         n1 = n2;
1386                         }
1387                         n1->output(n1, skb);
1388                         if (n2)
1389                                 neigh_release(n2);
1390                         rcu_read_unlock();
1391
1392                         write_lock_bh(&neigh->lock);
1393                 }
1394                 __skb_queue_purge(&neigh->arp_queue);
1395                 neigh->arp_queue_len_bytes = 0;
1396         }
1397 out:
1398         if (update_isrouter)
1399                 neigh_update_is_router(neigh, flags, &notify);
1400         write_unlock_bh(&neigh->lock);
1401
1402         if (((new ^ old) & NUD_PERMANENT) || ext_learn_change)
1403                 neigh_update_gc_list(neigh);
1404
1405         if (notify)
1406                 neigh_update_notify(neigh, nlmsg_pid);
1407
1408         trace_neigh_update_done(neigh, err);
1409
1410         return err;
1411 }
1412
1413 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
1414                  u32 flags, u32 nlmsg_pid)
1415 {
1416         return __neigh_update(neigh, lladdr, new, flags, nlmsg_pid, NULL);
1417 }
1418 EXPORT_SYMBOL(neigh_update);
1419
1420 /* Update the neigh to listen temporarily for probe responses, even if it is
1421  * in a NUD_FAILED state. The caller has to hold neigh->lock for writing.
1422  */
1423 void __neigh_set_probe_once(struct neighbour *neigh)
1424 {
1425         if (neigh->dead)
1426                 return;
1427         neigh->updated = jiffies;
1428         if (!(neigh->nud_state & NUD_FAILED))
1429                 return;
1430         neigh->nud_state = NUD_INCOMPLETE;
1431         atomic_set(&neigh->probes, neigh_max_probes(neigh));
1432         neigh_add_timer(neigh,
1433                         jiffies + NEIGH_VAR(neigh->parms, RETRANS_TIME));
1434 }
1435 EXPORT_SYMBOL(__neigh_set_probe_once);
1436
1437 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
1438                                  u8 *lladdr, void *saddr,
1439                                  struct net_device *dev)
1440 {
1441         struct neighbour *neigh = __neigh_lookup(tbl, saddr, dev,
1442                                                  lladdr || !dev->addr_len);
1443         if (neigh)
1444                 neigh_update(neigh, lladdr, NUD_STALE,
1445                              NEIGH_UPDATE_F_OVERRIDE, 0);
1446         return neigh;
1447 }
1448 EXPORT_SYMBOL(neigh_event_ns);
1449
1450 /* called with read_lock_bh(&n->lock); */
1451 static void neigh_hh_init(struct neighbour *n)
1452 {
1453         struct net_device *dev = n->dev;
1454         __be16 prot = n->tbl->protocol;
1455         struct hh_cache *hh = &n->hh;
1456
1457         write_lock_bh(&n->lock);
1458
1459         /* Only one thread can come in here and initialize the
1460          * hh_cache entry.
1461          */
1462         if (!hh->hh_len)
1463                 dev->header_ops->cache(n, hh, prot);
1464
1465         write_unlock_bh(&n->lock);
1466 }
1467
1468 /* Slow and careful. */
1469
1470 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb)
1471 {
1472         int rc = 0;
1473
1474         if (!neigh_event_send(neigh, skb)) {
1475                 int err;
1476                 struct net_device *dev = neigh->dev;
1477                 unsigned int seq;
1478
1479                 if (dev->header_ops->cache && !neigh->hh.hh_len)
1480                         neigh_hh_init(neigh);
1481
1482                 do {
1483                         __skb_pull(skb, skb_network_offset(skb));
1484                         seq = read_seqbegin(&neigh->ha_lock);
1485                         err = dev_hard_header(skb, dev, ntohs(skb->protocol),
1486                                               neigh->ha, NULL, skb->len);
1487                 } while (read_seqretry(&neigh->ha_lock, seq));
1488
1489                 if (err >= 0)
1490                         rc = dev_queue_xmit(skb);
1491                 else
1492                         goto out_kfree_skb;
1493         }
1494 out:
1495         return rc;
1496 out_kfree_skb:
1497         rc = -EINVAL;
1498         kfree_skb(skb);
1499         goto out;
1500 }
1501 EXPORT_SYMBOL(neigh_resolve_output);
1502
1503 /* As fast as possible without hh cache */
1504
1505 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb)
1506 {
1507         struct net_device *dev = neigh->dev;
1508         unsigned int seq;
1509         int err;
1510
1511         do {
1512                 __skb_pull(skb, skb_network_offset(skb));
1513                 seq = read_seqbegin(&neigh->ha_lock);
1514                 err = dev_hard_header(skb, dev, ntohs(skb->protocol),
1515                                       neigh->ha, NULL, skb->len);
1516         } while (read_seqretry(&neigh->ha_lock, seq));
1517
1518         if (err >= 0)
1519                 err = dev_queue_xmit(skb);
1520         else {
1521                 err = -EINVAL;
1522                 kfree_skb(skb);
1523         }
1524         return err;
1525 }
1526 EXPORT_SYMBOL(neigh_connected_output);
1527
1528 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb)
1529 {
1530         return dev_queue_xmit(skb);
1531 }
1532 EXPORT_SYMBOL(neigh_direct_output);
1533
1534 static void neigh_proxy_process(struct timer_list *t)
1535 {
1536         struct neigh_table *tbl = from_timer(tbl, t, proxy_timer);
1537         long sched_next = 0;
1538         unsigned long now = jiffies;
1539         struct sk_buff *skb, *n;
1540
1541         spin_lock(&tbl->proxy_queue.lock);
1542
1543         skb_queue_walk_safe(&tbl->proxy_queue, skb, n) {
1544                 long tdif = NEIGH_CB(skb)->sched_next - now;
1545
1546                 if (tdif <= 0) {
1547                         struct net_device *dev = skb->dev;
1548
1549                         __skb_unlink(skb, &tbl->proxy_queue);
1550                         if (tbl->proxy_redo && netif_running(dev)) {
1551                                 rcu_read_lock();
1552                                 tbl->proxy_redo(skb);
1553                                 rcu_read_unlock();
1554                         } else {
1555                                 kfree_skb(skb);
1556                         }
1557
1558                         dev_put(dev);
1559                 } else if (!sched_next || tdif < sched_next)
1560                         sched_next = tdif;
1561         }
1562         del_timer(&tbl->proxy_timer);
1563         if (sched_next)
1564                 mod_timer(&tbl->proxy_timer, jiffies + sched_next);
1565         spin_unlock(&tbl->proxy_queue.lock);
1566 }
1567
1568 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
1569                     struct sk_buff *skb)
1570 {
1571         unsigned long now = jiffies;
1572
1573         unsigned long sched_next = now + (prandom_u32() %
1574                                           NEIGH_VAR(p, PROXY_DELAY));
1575
1576         if (tbl->proxy_queue.qlen > NEIGH_VAR(p, PROXY_QLEN)) {
1577                 kfree_skb(skb);
1578                 return;
1579         }
1580
1581         NEIGH_CB(skb)->sched_next = sched_next;
1582         NEIGH_CB(skb)->flags |= LOCALLY_ENQUEUED;
1583
1584         spin_lock(&tbl->proxy_queue.lock);
1585         if (del_timer(&tbl->proxy_timer)) {
1586                 if (time_before(tbl->proxy_timer.expires, sched_next))
1587                         sched_next = tbl->proxy_timer.expires;
1588         }
1589         skb_dst_drop(skb);
1590         dev_hold(skb->dev);
1591         __skb_queue_tail(&tbl->proxy_queue, skb);
1592         mod_timer(&tbl->proxy_timer, sched_next);
1593         spin_unlock(&tbl->proxy_queue.lock);
1594 }
1595 EXPORT_SYMBOL(pneigh_enqueue);
1596
1597 static inline struct neigh_parms *lookup_neigh_parms(struct neigh_table *tbl,
1598                                                       struct net *net, int ifindex)
1599 {
1600         struct neigh_parms *p;
1601
1602         list_for_each_entry(p, &tbl->parms_list, list) {
1603                 if ((p->dev && p->dev->ifindex == ifindex && net_eq(neigh_parms_net(p), net)) ||
1604                     (!p->dev && !ifindex && net_eq(net, &init_net)))
1605                         return p;
1606         }
1607
1608         return NULL;
1609 }
1610
1611 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
1612                                       struct neigh_table *tbl)
1613 {
1614         struct neigh_parms *p;
1615         struct net *net = dev_net(dev);
1616         const struct net_device_ops *ops = dev->netdev_ops;
1617
1618         p = kmemdup(&tbl->parms, sizeof(*p), GFP_KERNEL);
1619         if (p) {
1620                 p->tbl            = tbl;
1621                 refcount_set(&p->refcnt, 1);
1622                 p->reachable_time =
1623                                 neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
1624                 dev_hold(dev);
1625                 p->dev = dev;
1626                 write_pnet(&p->net, net);
1627                 p->sysctl_table = NULL;
1628
1629                 if (ops->ndo_neigh_setup && ops->ndo_neigh_setup(dev, p)) {
1630                         dev_put(dev);
1631                         kfree(p);
1632                         return NULL;
1633                 }
1634
1635                 write_lock_bh(&tbl->lock);
1636                 list_add(&p->list, &tbl->parms.list);
1637                 write_unlock_bh(&tbl->lock);
1638
1639                 neigh_parms_data_state_cleanall(p);
1640         }
1641         return p;
1642 }
1643 EXPORT_SYMBOL(neigh_parms_alloc);
1644
1645 static void neigh_rcu_free_parms(struct rcu_head *head)
1646 {
1647         struct neigh_parms *parms =
1648                 container_of(head, struct neigh_parms, rcu_head);
1649
1650         neigh_parms_put(parms);
1651 }
1652
1653 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
1654 {
1655         if (!parms || parms == &tbl->parms)
1656                 return;
1657         write_lock_bh(&tbl->lock);
1658         list_del(&parms->list);
1659         parms->dead = 1;
1660         write_unlock_bh(&tbl->lock);
1661         if (parms->dev)
1662                 dev_put(parms->dev);
1663         call_rcu(&parms->rcu_head, neigh_rcu_free_parms);
1664 }
1665 EXPORT_SYMBOL(neigh_parms_release);
1666
1667 static void neigh_parms_destroy(struct neigh_parms *parms)
1668 {
1669         kfree(parms);
1670 }
1671
1672 static struct lock_class_key neigh_table_proxy_queue_class;
1673
1674 static struct neigh_table *neigh_tables[NEIGH_NR_TABLES] __read_mostly;
1675
1676 void neigh_table_init(int index, struct neigh_table *tbl)
1677 {
1678         unsigned long now = jiffies;
1679         unsigned long phsize;
1680
1681         INIT_LIST_HEAD(&tbl->parms_list);
1682         INIT_LIST_HEAD(&tbl->gc_list);
1683         list_add(&tbl->parms.list, &tbl->parms_list);
1684         write_pnet(&tbl->parms.net, &init_net);
1685         refcount_set(&tbl->parms.refcnt, 1);
1686         tbl->parms.reachable_time =
1687                           neigh_rand_reach_time(NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME));
1688
1689         tbl->stats = alloc_percpu(struct neigh_statistics);
1690         if (!tbl->stats)
1691                 panic("cannot create neighbour cache statistics");
1692
1693 #ifdef CONFIG_PROC_FS
1694         if (!proc_create_seq_data(tbl->id, 0, init_net.proc_net_stat,
1695                               &neigh_stat_seq_ops, tbl))
1696                 panic("cannot create neighbour proc dir entry");
1697 #endif
1698
1699         RCU_INIT_POINTER(tbl->nht, neigh_hash_alloc(3));
1700
1701         phsize = (PNEIGH_HASHMASK + 1) * sizeof(struct pneigh_entry *);
1702         tbl->phash_buckets = kzalloc(phsize, GFP_KERNEL);
1703
1704         if (!tbl->nht || !tbl->phash_buckets)
1705                 panic("cannot allocate neighbour cache hashes");
1706
1707         if (!tbl->entry_size)
1708                 tbl->entry_size = ALIGN(offsetof(struct neighbour, primary_key) +
1709                                         tbl->key_len, NEIGH_PRIV_ALIGN);
1710         else
1711                 WARN_ON(tbl->entry_size % NEIGH_PRIV_ALIGN);
1712
1713         rwlock_init(&tbl->lock);
1714         INIT_DEFERRABLE_WORK(&tbl->gc_work, neigh_periodic_work);
1715         queue_delayed_work(system_power_efficient_wq, &tbl->gc_work,
1716                         tbl->parms.reachable_time);
1717         timer_setup(&tbl->proxy_timer, neigh_proxy_process, 0);
1718         skb_queue_head_init_class(&tbl->proxy_queue,
1719                         &neigh_table_proxy_queue_class);
1720
1721         tbl->last_flush = now;
1722         tbl->last_rand  = now + tbl->parms.reachable_time * 20;
1723
1724         neigh_tables[index] = tbl;
1725 }
1726 EXPORT_SYMBOL(neigh_table_init);
1727
1728 int neigh_table_clear(int index, struct neigh_table *tbl)
1729 {
1730         neigh_tables[index] = NULL;
1731         /* It is not clean... Fix it to unload IPv6 module safely */
1732         cancel_delayed_work_sync(&tbl->gc_work);
1733         del_timer_sync(&tbl->proxy_timer);
1734         pneigh_queue_purge(&tbl->proxy_queue);
1735         neigh_ifdown(tbl, NULL);
1736         if (atomic_read(&tbl->entries))
1737                 pr_crit("neighbour leakage\n");
1738
1739         call_rcu(&rcu_dereference_protected(tbl->nht, 1)->rcu,
1740                  neigh_hash_free_rcu);
1741         tbl->nht = NULL;
1742
1743         kfree(tbl->phash_buckets);
1744         tbl->phash_buckets = NULL;
1745
1746         remove_proc_entry(tbl->id, init_net.proc_net_stat);
1747
1748         free_percpu(tbl->stats);
1749         tbl->stats = NULL;
1750
1751         return 0;
1752 }
1753 EXPORT_SYMBOL(neigh_table_clear);
1754
1755 static struct neigh_table *neigh_find_table(int family)
1756 {
1757         struct neigh_table *tbl = NULL;
1758
1759         switch (family) {
1760         case AF_INET:
1761                 tbl = neigh_tables[NEIGH_ARP_TABLE];
1762                 break;
1763         case AF_INET6:
1764                 tbl = neigh_tables[NEIGH_ND_TABLE];
1765                 break;
1766         case AF_DECnet:
1767                 tbl = neigh_tables[NEIGH_DN_TABLE];
1768                 break;
1769         }
1770
1771         return tbl;
1772 }
1773
1774 const struct nla_policy nda_policy[NDA_MAX+1] = {
1775         [NDA_DST]               = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
1776         [NDA_LLADDR]            = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
1777         [NDA_CACHEINFO]         = { .len = sizeof(struct nda_cacheinfo) },
1778         [NDA_PROBES]            = { .type = NLA_U32 },
1779         [NDA_VLAN]              = { .type = NLA_U16 },
1780         [NDA_PORT]              = { .type = NLA_U16 },
1781         [NDA_VNI]               = { .type = NLA_U32 },
1782         [NDA_IFINDEX]           = { .type = NLA_U32 },
1783         [NDA_MASTER]            = { .type = NLA_U32 },
1784         [NDA_PROTOCOL]          = { .type = NLA_U8 },
1785 };
1786
1787 static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh,
1788                         struct netlink_ext_ack *extack)
1789 {
1790         struct net *net = sock_net(skb->sk);
1791         struct ndmsg *ndm;
1792         struct nlattr *dst_attr;
1793         struct neigh_table *tbl;
1794         struct neighbour *neigh;
1795         struct net_device *dev = NULL;
1796         int err = -EINVAL;
1797
1798         ASSERT_RTNL();
1799         if (nlmsg_len(nlh) < sizeof(*ndm))
1800                 goto out;
1801
1802         dst_attr = nlmsg_find_attr(nlh, sizeof(*ndm), NDA_DST);
1803         if (!dst_attr) {
1804                 NL_SET_ERR_MSG(extack, "Network address not specified");
1805                 goto out;
1806         }
1807
1808         ndm = nlmsg_data(nlh);
1809         if (ndm->ndm_ifindex) {
1810                 dev = __dev_get_by_index(net, ndm->ndm_ifindex);
1811                 if (dev == NULL) {
1812                         err = -ENODEV;
1813                         goto out;
1814                 }
1815         }
1816
1817         tbl = neigh_find_table(ndm->ndm_family);
1818         if (tbl == NULL)
1819                 return -EAFNOSUPPORT;
1820
1821         if (nla_len(dst_attr) < (int)tbl->key_len) {
1822                 NL_SET_ERR_MSG(extack, "Invalid network address");
1823                 goto out;
1824         }
1825
1826         if (ndm->ndm_flags & NTF_PROXY) {
1827                 err = pneigh_delete(tbl, net, nla_data(dst_attr), dev);
1828                 goto out;
1829         }
1830
1831         if (dev == NULL)
1832                 goto out;
1833
1834         neigh = neigh_lookup(tbl, nla_data(dst_attr), dev);
1835         if (neigh == NULL) {
1836                 err = -ENOENT;
1837                 goto out;
1838         }
1839
1840         err = __neigh_update(neigh, NULL, NUD_FAILED,
1841                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN,
1842                              NETLINK_CB(skb).portid, extack);
1843         write_lock_bh(&tbl->lock);
1844         neigh_release(neigh);
1845         neigh_remove_one(neigh, tbl);
1846         write_unlock_bh(&tbl->lock);
1847
1848 out:
1849         return err;
1850 }
1851
1852 static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh,
1853                      struct netlink_ext_ack *extack)
1854 {
1855         int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE |
1856                 NEIGH_UPDATE_F_OVERRIDE_ISROUTER;
1857         struct net *net = sock_net(skb->sk);
1858         struct ndmsg *ndm;
1859         struct nlattr *tb[NDA_MAX+1];
1860         struct neigh_table *tbl;
1861         struct net_device *dev = NULL;
1862         struct neighbour *neigh;
1863         void *dst, *lladdr;
1864         u8 protocol = 0;
1865         int err;
1866
1867         ASSERT_RTNL();
1868         err = nlmsg_parse_deprecated(nlh, sizeof(*ndm), tb, NDA_MAX,
1869                                      nda_policy, extack);
1870         if (err < 0)
1871                 goto out;
1872
1873         err = -EINVAL;
1874         if (!tb[NDA_DST]) {
1875                 NL_SET_ERR_MSG(extack, "Network address not specified");
1876                 goto out;
1877         }
1878
1879         ndm = nlmsg_data(nlh);
1880         if (ndm->ndm_ifindex) {
1881                 dev = __dev_get_by_index(net, ndm->ndm_ifindex);
1882                 if (dev == NULL) {
1883                         err = -ENODEV;
1884                         goto out;
1885                 }
1886
1887                 if (tb[NDA_LLADDR] && nla_len(tb[NDA_LLADDR]) < dev->addr_len) {
1888                         NL_SET_ERR_MSG(extack, "Invalid link address");
1889                         goto out;
1890                 }
1891         }
1892
1893         tbl = neigh_find_table(ndm->ndm_family);
1894         if (tbl == NULL)
1895                 return -EAFNOSUPPORT;
1896
1897         if (nla_len(tb[NDA_DST]) < (int)tbl->key_len) {
1898                 NL_SET_ERR_MSG(extack, "Invalid network address");
1899                 goto out;
1900         }
1901
1902         dst = nla_data(tb[NDA_DST]);
1903         lladdr = tb[NDA_LLADDR] ? nla_data(tb[NDA_LLADDR]) : NULL;
1904
1905         if (tb[NDA_PROTOCOL])
1906                 protocol = nla_get_u8(tb[NDA_PROTOCOL]);
1907
1908         if (ndm->ndm_flags & NTF_PROXY) {
1909                 struct pneigh_entry *pn;
1910
1911                 err = -ENOBUFS;
1912                 pn = pneigh_lookup(tbl, net, dst, dev, 1);
1913                 if (pn) {
1914                         pn->flags = ndm->ndm_flags;
1915                         if (protocol)
1916                                 pn->protocol = protocol;
1917                         err = 0;
1918                 }
1919                 goto out;
1920         }
1921
1922         if (!dev) {
1923                 NL_SET_ERR_MSG(extack, "Device not specified");
1924                 goto out;
1925         }
1926
1927         if (tbl->allow_add && !tbl->allow_add(dev, extack)) {
1928                 err = -EINVAL;
1929                 goto out;
1930         }
1931
1932         neigh = neigh_lookup(tbl, dst, dev);
1933         if (neigh == NULL) {
1934                 bool exempt_from_gc;
1935
1936                 if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
1937                         err = -ENOENT;
1938                         goto out;
1939                 }
1940
1941                 exempt_from_gc = ndm->ndm_state & NUD_PERMANENT ||
1942                                  ndm->ndm_flags & NTF_EXT_LEARNED;
1943                 neigh = ___neigh_create(tbl, dst, dev, exempt_from_gc, true);
1944                 if (IS_ERR(neigh)) {
1945                         err = PTR_ERR(neigh);
1946                         goto out;
1947                 }
1948         } else {
1949                 if (nlh->nlmsg_flags & NLM_F_EXCL) {
1950                         err = -EEXIST;
1951                         neigh_release(neigh);
1952                         goto out;
1953                 }
1954
1955                 if (!(nlh->nlmsg_flags & NLM_F_REPLACE))
1956                         flags &= ~(NEIGH_UPDATE_F_OVERRIDE |
1957                                    NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1958         }
1959
1960         if (ndm->ndm_flags & NTF_EXT_LEARNED)
1961                 flags |= NEIGH_UPDATE_F_EXT_LEARNED;
1962
1963         if (ndm->ndm_flags & NTF_ROUTER)
1964                 flags |= NEIGH_UPDATE_F_ISROUTER;
1965
1966         if (ndm->ndm_flags & NTF_USE) {
1967                 neigh_event_send(neigh, NULL);
1968                 err = 0;
1969         } else
1970                 err = __neigh_update(neigh, lladdr, ndm->ndm_state, flags,
1971                                      NETLINK_CB(skb).portid, extack);
1972
1973         if (protocol)
1974                 neigh->protocol = protocol;
1975
1976         neigh_release(neigh);
1977
1978 out:
1979         return err;
1980 }
1981
1982 static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms)
1983 {
1984         struct nlattr *nest;
1985
1986         nest = nla_nest_start_noflag(skb, NDTA_PARMS);
1987         if (nest == NULL)
1988                 return -ENOBUFS;
1989
1990         if ((parms->dev &&
1991              nla_put_u32(skb, NDTPA_IFINDEX, parms->dev->ifindex)) ||
1992             nla_put_u32(skb, NDTPA_REFCNT, refcount_read(&parms->refcnt)) ||
1993             nla_put_u32(skb, NDTPA_QUEUE_LENBYTES,
1994                         NEIGH_VAR(parms, QUEUE_LEN_BYTES)) ||
1995             /* approximative value for deprecated QUEUE_LEN (in packets) */
1996             nla_put_u32(skb, NDTPA_QUEUE_LEN,
1997                         NEIGH_VAR(parms, QUEUE_LEN_BYTES) / SKB_TRUESIZE(ETH_FRAME_LEN)) ||
1998             nla_put_u32(skb, NDTPA_PROXY_QLEN, NEIGH_VAR(parms, PROXY_QLEN)) ||
1999             nla_put_u32(skb, NDTPA_APP_PROBES, NEIGH_VAR(parms, APP_PROBES)) ||
2000             nla_put_u32(skb, NDTPA_UCAST_PROBES,
2001                         NEIGH_VAR(parms, UCAST_PROBES)) ||
2002             nla_put_u32(skb, NDTPA_MCAST_PROBES,
2003                         NEIGH_VAR(parms, MCAST_PROBES)) ||
2004             nla_put_u32(skb, NDTPA_MCAST_REPROBES,
2005                         NEIGH_VAR(parms, MCAST_REPROBES)) ||
2006             nla_put_msecs(skb, NDTPA_REACHABLE_TIME, parms->reachable_time,
2007                           NDTPA_PAD) ||
2008             nla_put_msecs(skb, NDTPA_BASE_REACHABLE_TIME,
2009                           NEIGH_VAR(parms, BASE_REACHABLE_TIME), NDTPA_PAD) ||
2010             nla_put_msecs(skb, NDTPA_GC_STALETIME,
2011                           NEIGH_VAR(parms, GC_STALETIME), NDTPA_PAD) ||
2012             nla_put_msecs(skb, NDTPA_DELAY_PROBE_TIME,
2013                           NEIGH_VAR(parms, DELAY_PROBE_TIME), NDTPA_PAD) ||
2014             nla_put_msecs(skb, NDTPA_RETRANS_TIME,
2015                           NEIGH_VAR(parms, RETRANS_TIME), NDTPA_PAD) ||
2016             nla_put_msecs(skb, NDTPA_ANYCAST_DELAY,
2017                           NEIGH_VAR(parms, ANYCAST_DELAY), NDTPA_PAD) ||
2018             nla_put_msecs(skb, NDTPA_PROXY_DELAY,
2019                           NEIGH_VAR(parms, PROXY_DELAY), NDTPA_PAD) ||
2020             nla_put_msecs(skb, NDTPA_LOCKTIME,
2021                           NEIGH_VAR(parms, LOCKTIME), NDTPA_PAD))
2022                 goto nla_put_failure;
2023         return nla_nest_end(skb, nest);
2024
2025 nla_put_failure:
2026         nla_nest_cancel(skb, nest);
2027         return -EMSGSIZE;
2028 }
2029
2030 static int neightbl_fill_info(struct sk_buff *skb, struct neigh_table *tbl,
2031                               u32 pid, u32 seq, int type, int flags)
2032 {
2033         struct nlmsghdr *nlh;
2034         struct ndtmsg *ndtmsg;
2035
2036         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
2037         if (nlh == NULL)
2038                 return -EMSGSIZE;
2039
2040         ndtmsg = nlmsg_data(nlh);
2041
2042         read_lock_bh(&tbl->lock);
2043         ndtmsg->ndtm_family = tbl->family;
2044         ndtmsg->ndtm_pad1   = 0;
2045         ndtmsg->ndtm_pad2   = 0;
2046
2047         if (nla_put_string(skb, NDTA_NAME, tbl->id) ||
2048             nla_put_msecs(skb, NDTA_GC_INTERVAL, tbl->gc_interval, NDTA_PAD) ||
2049             nla_put_u32(skb, NDTA_THRESH1, tbl->gc_thresh1) ||
2050             nla_put_u32(skb, NDTA_THRESH2, tbl->gc_thresh2) ||
2051             nla_put_u32(skb, NDTA_THRESH3, tbl->gc_thresh3))
2052                 goto nla_put_failure;
2053         {
2054                 unsigned long now = jiffies;
2055                 unsigned int flush_delta = now - tbl->last_flush;
2056                 unsigned int rand_delta = now - tbl->last_rand;
2057                 struct neigh_hash_table *nht;
2058                 struct ndt_config ndc = {
2059                         .ndtc_key_len           = tbl->key_len,
2060                         .ndtc_entry_size        = tbl->entry_size,
2061                         .ndtc_entries           = atomic_read(&tbl->entries),
2062                         .ndtc_last_flush        = jiffies_to_msecs(flush_delta),
2063                         .ndtc_last_rand         = jiffies_to_msecs(rand_delta),
2064                         .ndtc_proxy_qlen        = tbl->proxy_queue.qlen,
2065                 };
2066
2067                 rcu_read_lock_bh();
2068                 nht = rcu_dereference_bh(tbl->nht);
2069                 ndc.ndtc_hash_rnd = nht->hash_rnd[0];
2070                 ndc.ndtc_hash_mask = ((1 << nht->hash_shift) - 1);
2071                 rcu_read_unlock_bh();
2072
2073                 if (nla_put(skb, NDTA_CONFIG, sizeof(ndc), &ndc))
2074                         goto nla_put_failure;
2075         }
2076
2077         {
2078                 int cpu;
2079                 struct ndt_stats ndst;
2080
2081                 memset(&ndst, 0, sizeof(ndst));
2082
2083                 for_each_possible_cpu(cpu) {
2084                         struct neigh_statistics *st;
2085
2086                         st = per_cpu_ptr(tbl->stats, cpu);
2087                         ndst.ndts_allocs                += st->allocs;
2088                         ndst.ndts_destroys              += st->destroys;
2089                         ndst.ndts_hash_grows            += st->hash_grows;
2090                         ndst.ndts_res_failed            += st->res_failed;
2091                         ndst.ndts_lookups               += st->lookups;
2092                         ndst.ndts_hits                  += st->hits;
2093                         ndst.ndts_rcv_probes_mcast      += st->rcv_probes_mcast;
2094                         ndst.ndts_rcv_probes_ucast      += st->rcv_probes_ucast;
2095                         ndst.ndts_periodic_gc_runs      += st->periodic_gc_runs;
2096                         ndst.ndts_forced_gc_runs        += st->forced_gc_runs;
2097                         ndst.ndts_table_fulls           += st->table_fulls;
2098                 }
2099
2100                 if (nla_put_64bit(skb, NDTA_STATS, sizeof(ndst), &ndst,
2101                                   NDTA_PAD))
2102                         goto nla_put_failure;
2103         }
2104
2105         BUG_ON(tbl->parms.dev);
2106         if (neightbl_fill_parms(skb, &tbl->parms) < 0)
2107                 goto nla_put_failure;
2108
2109         read_unlock_bh(&tbl->lock);
2110         nlmsg_end(skb, nlh);
2111         return 0;
2112
2113 nla_put_failure:
2114         read_unlock_bh(&tbl->lock);
2115         nlmsg_cancel(skb, nlh);
2116         return -EMSGSIZE;
2117 }
2118
2119 static int neightbl_fill_param_info(struct sk_buff *skb,
2120                                     struct neigh_table *tbl,
2121                                     struct neigh_parms *parms,
2122                                     u32 pid, u32 seq, int type,
2123                                     unsigned int flags)
2124 {
2125         struct ndtmsg *ndtmsg;
2126         struct nlmsghdr *nlh;
2127
2128         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
2129         if (nlh == NULL)
2130                 return -EMSGSIZE;
2131
2132         ndtmsg = nlmsg_data(nlh);
2133
2134         read_lock_bh(&tbl->lock);
2135         ndtmsg->ndtm_family = tbl->family;
2136         ndtmsg->ndtm_pad1   = 0;
2137         ndtmsg->ndtm_pad2   = 0;
2138
2139         if (nla_put_string(skb, NDTA_NAME, tbl->id) < 0 ||
2140             neightbl_fill_parms(skb, parms) < 0)
2141                 goto errout;
2142
2143         read_unlock_bh(&tbl->lock);
2144         nlmsg_end(skb, nlh);
2145         return 0;
2146 errout:
2147         read_unlock_bh(&tbl->lock);
2148         nlmsg_cancel(skb, nlh);
2149         return -EMSGSIZE;
2150 }
2151
2152 static const struct nla_policy nl_neightbl_policy[NDTA_MAX+1] = {
2153         [NDTA_NAME]             = { .type = NLA_STRING },
2154         [NDTA_THRESH1]          = { .type = NLA_U32 },
2155         [NDTA_THRESH2]          = { .type = NLA_U32 },
2156         [NDTA_THRESH3]          = { .type = NLA_U32 },
2157         [NDTA_GC_INTERVAL]      = { .type = NLA_U64 },
2158         [NDTA_PARMS]            = { .type = NLA_NESTED },
2159 };
2160
2161 static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
2162         [NDTPA_IFINDEX]                 = { .type = NLA_U32 },
2163         [NDTPA_QUEUE_LEN]               = { .type = NLA_U32 },
2164         [NDTPA_PROXY_QLEN]              = { .type = NLA_U32 },
2165         [NDTPA_APP_PROBES]              = { .type = NLA_U32 },
2166         [NDTPA_UCAST_PROBES]            = { .type = NLA_U32 },
2167         [NDTPA_MCAST_PROBES]            = { .type = NLA_U32 },
2168         [NDTPA_MCAST_REPROBES]          = { .type = NLA_U32 },
2169         [NDTPA_BASE_REACHABLE_TIME]     = { .type = NLA_U64 },
2170         [NDTPA_GC_STALETIME]            = { .type = NLA_U64 },
2171         [NDTPA_DELAY_PROBE_TIME]        = { .type = NLA_U64 },
2172         [NDTPA_RETRANS_TIME]            = { .type = NLA_U64 },
2173         [NDTPA_ANYCAST_DELAY]           = { .type = NLA_U64 },
2174         [NDTPA_PROXY_DELAY]             = { .type = NLA_U64 },
2175         [NDTPA_LOCKTIME]                = { .type = NLA_U64 },
2176 };
2177
2178 static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh,
2179                         struct netlink_ext_ack *extack)
2180 {
2181         struct net *net = sock_net(skb->sk);
2182         struct neigh_table *tbl;
2183         struct ndtmsg *ndtmsg;
2184         struct nlattr *tb[NDTA_MAX+1];
2185         bool found = false;
2186         int err, tidx;
2187
2188         err = nlmsg_parse_deprecated(nlh, sizeof(*ndtmsg), tb, NDTA_MAX,
2189                                      nl_neightbl_policy, extack);
2190         if (err < 0)
2191                 goto errout;
2192
2193         if (tb[NDTA_NAME] == NULL) {
2194                 err = -EINVAL;
2195                 goto errout;
2196         }
2197
2198         ndtmsg = nlmsg_data(nlh);
2199
2200         for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) {
2201                 tbl = neigh_tables[tidx];
2202                 if (!tbl)
2203                         continue;
2204                 if (ndtmsg->ndtm_family && tbl->family != ndtmsg->ndtm_family)
2205                         continue;
2206                 if (nla_strcmp(tb[NDTA_NAME], tbl->id) == 0) {
2207                         found = true;
2208                         break;
2209                 }
2210         }
2211
2212         if (!found)
2213                 return -ENOENT;
2214
2215         /*
2216          * We acquire tbl->lock to be nice to the periodic timers and
2217          * make sure they always see a consistent set of values.
2218          */
2219         write_lock_bh(&tbl->lock);
2220
2221         if (tb[NDTA_PARMS]) {
2222                 struct nlattr *tbp[NDTPA_MAX+1];
2223                 struct neigh_parms *p;
2224                 int i, ifindex = 0;
2225
2226                 err = nla_parse_nested_deprecated(tbp, NDTPA_MAX,
2227                                                   tb[NDTA_PARMS],
2228                                                   nl_ntbl_parm_policy, extack);
2229                 if (err < 0)
2230                         goto errout_tbl_lock;
2231
2232                 if (tbp[NDTPA_IFINDEX])
2233                         ifindex = nla_get_u32(tbp[NDTPA_IFINDEX]);
2234
2235                 p = lookup_neigh_parms(tbl, net, ifindex);
2236                 if (p == NULL) {
2237                         err = -ENOENT;
2238                         goto errout_tbl_lock;
2239                 }
2240
2241                 for (i = 1; i <= NDTPA_MAX; i++) {
2242                         if (tbp[i] == NULL)
2243                                 continue;
2244
2245                         switch (i) {
2246                         case NDTPA_QUEUE_LEN:
2247                                 NEIGH_VAR_SET(p, QUEUE_LEN_BYTES,
2248                                               nla_get_u32(tbp[i]) *
2249                                               SKB_TRUESIZE(ETH_FRAME_LEN));
2250                                 break;
2251                         case NDTPA_QUEUE_LENBYTES:
2252                                 NEIGH_VAR_SET(p, QUEUE_LEN_BYTES,
2253                                               nla_get_u32(tbp[i]));
2254                                 break;
2255                         case NDTPA_PROXY_QLEN:
2256                                 NEIGH_VAR_SET(p, PROXY_QLEN,
2257                                               nla_get_u32(tbp[i]));
2258                                 break;
2259                         case NDTPA_APP_PROBES:
2260                                 NEIGH_VAR_SET(p, APP_PROBES,
2261                                               nla_get_u32(tbp[i]));
2262                                 break;
2263                         case NDTPA_UCAST_PROBES:
2264                                 NEIGH_VAR_SET(p, UCAST_PROBES,
2265                                               nla_get_u32(tbp[i]));
2266                                 break;
2267                         case NDTPA_MCAST_PROBES:
2268                                 NEIGH_VAR_SET(p, MCAST_PROBES,
2269                                               nla_get_u32(tbp[i]));
2270                                 break;
2271                         case NDTPA_MCAST_REPROBES:
2272                                 NEIGH_VAR_SET(p, MCAST_REPROBES,
2273                                               nla_get_u32(tbp[i]));
2274                                 break;
2275                         case NDTPA_BASE_REACHABLE_TIME:
2276                                 NEIGH_VAR_SET(p, BASE_REACHABLE_TIME,
2277                                               nla_get_msecs(tbp[i]));
2278                                 /* update reachable_time as well, otherwise, the change will
2279                                  * only be effective after the next time neigh_periodic_work
2280                                  * decides to recompute it (can be multiple minutes)
2281                                  */
2282                                 p->reachable_time =
2283                                         neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
2284                                 break;
2285                         case NDTPA_GC_STALETIME:
2286                                 NEIGH_VAR_SET(p, GC_STALETIME,
2287                                               nla_get_msecs(tbp[i]));
2288                                 break;
2289                         case NDTPA_DELAY_PROBE_TIME:
2290                                 NEIGH_VAR_SET(p, DELAY_PROBE_TIME,
2291                                               nla_get_msecs(tbp[i]));
2292                                 call_netevent_notifiers(NETEVENT_DELAY_PROBE_TIME_UPDATE, p);
2293                                 break;
2294                         case NDTPA_RETRANS_TIME:
2295                                 NEIGH_VAR_SET(p, RETRANS_TIME,
2296                                               nla_get_msecs(tbp[i]));
2297                                 break;
2298                         case NDTPA_ANYCAST_DELAY:
2299                                 NEIGH_VAR_SET(p, ANYCAST_DELAY,
2300                                               nla_get_msecs(tbp[i]));
2301                                 break;
2302                         case NDTPA_PROXY_DELAY:
2303                                 NEIGH_VAR_SET(p, PROXY_DELAY,
2304                                               nla_get_msecs(tbp[i]));
2305                                 break;
2306                         case NDTPA_LOCKTIME:
2307                                 NEIGH_VAR_SET(p, LOCKTIME,
2308                                               nla_get_msecs(tbp[i]));
2309                                 break;
2310                         }
2311                 }
2312         }
2313
2314         err = -ENOENT;
2315         if ((tb[NDTA_THRESH1] || tb[NDTA_THRESH2] ||
2316              tb[NDTA_THRESH3] || tb[NDTA_GC_INTERVAL]) &&
2317             !net_eq(net, &init_net))
2318                 goto errout_tbl_lock;
2319
2320         if (tb[NDTA_THRESH1])
2321                 tbl->gc_thresh1 = nla_get_u32(tb[NDTA_THRESH1]);
2322
2323         if (tb[NDTA_THRESH2])
2324                 tbl->gc_thresh2 = nla_get_u32(tb[NDTA_THRESH2]);
2325
2326         if (tb[NDTA_THRESH3])
2327                 tbl->gc_thresh3 = nla_get_u32(tb[NDTA_THRESH3]);
2328
2329         if (tb[NDTA_GC_INTERVAL])
2330                 tbl->gc_interval = nla_get_msecs(tb[NDTA_GC_INTERVAL]);
2331
2332         err = 0;
2333
2334 errout_tbl_lock:
2335         write_unlock_bh(&tbl->lock);
2336 errout:
2337         return err;
2338 }
2339
2340 static int neightbl_valid_dump_info(const struct nlmsghdr *nlh,
2341                                     struct netlink_ext_ack *extack)
2342 {
2343         struct ndtmsg *ndtm;
2344
2345         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndtm))) {
2346                 NL_SET_ERR_MSG(extack, "Invalid header for neighbor table dump request");
2347                 return -EINVAL;
2348         }
2349
2350         ndtm = nlmsg_data(nlh);
2351         if (ndtm->ndtm_pad1  || ndtm->ndtm_pad2) {
2352                 NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor table dump request");
2353                 return -EINVAL;
2354         }
2355
2356         if (nlmsg_attrlen(nlh, sizeof(*ndtm))) {
2357                 NL_SET_ERR_MSG(extack, "Invalid data after header in neighbor table dump request");
2358                 return -EINVAL;
2359         }
2360
2361         return 0;
2362 }
2363
2364 static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2365 {
2366         const struct nlmsghdr *nlh = cb->nlh;
2367         struct net *net = sock_net(skb->sk);
2368         int family, tidx, nidx = 0;
2369         int tbl_skip = cb->args[0];
2370         int neigh_skip = cb->args[1];
2371         struct neigh_table *tbl;
2372
2373         if (cb->strict_check) {
2374                 int err = neightbl_valid_dump_info(nlh, cb->extack);
2375
2376                 if (err < 0)
2377                         return err;
2378         }
2379
2380         family = ((struct rtgenmsg *)nlmsg_data(nlh))->rtgen_family;
2381
2382         for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) {
2383                 struct neigh_parms *p;
2384
2385                 tbl = neigh_tables[tidx];
2386                 if (!tbl)
2387                         continue;
2388
2389                 if (tidx < tbl_skip || (family && tbl->family != family))
2390                         continue;
2391
2392                 if (neightbl_fill_info(skb, tbl, NETLINK_CB(cb->skb).portid,
2393                                        nlh->nlmsg_seq, RTM_NEWNEIGHTBL,
2394                                        NLM_F_MULTI) < 0)
2395                         break;
2396
2397                 nidx = 0;
2398                 p = list_next_entry(&tbl->parms, list);
2399                 list_for_each_entry_from(p, &tbl->parms_list, list) {
2400                         if (!net_eq(neigh_parms_net(p), net))
2401                                 continue;
2402
2403                         if (nidx < neigh_skip)
2404                                 goto next;
2405
2406                         if (neightbl_fill_param_info(skb, tbl, p,
2407                                                      NETLINK_CB(cb->skb).portid,
2408                                                      nlh->nlmsg_seq,
2409                                                      RTM_NEWNEIGHTBL,
2410                                                      NLM_F_MULTI) < 0)
2411                                 goto out;
2412                 next:
2413                         nidx++;
2414                 }
2415
2416                 neigh_skip = 0;
2417         }
2418 out:
2419         cb->args[0] = tidx;
2420         cb->args[1] = nidx;
2421
2422         return skb->len;
2423 }
2424
2425 static int neigh_fill_info(struct sk_buff *skb, struct neighbour *neigh,
2426                            u32 pid, u32 seq, int type, unsigned int flags)
2427 {
2428         unsigned long now = jiffies;
2429         struct nda_cacheinfo ci;
2430         struct nlmsghdr *nlh;
2431         struct ndmsg *ndm;
2432
2433         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
2434         if (nlh == NULL)
2435                 return -EMSGSIZE;
2436
2437         ndm = nlmsg_data(nlh);
2438         ndm->ndm_family  = neigh->ops->family;
2439         ndm->ndm_pad1    = 0;
2440         ndm->ndm_pad2    = 0;
2441         ndm->ndm_flags   = neigh->flags;
2442         ndm->ndm_type    = neigh->type;
2443         ndm->ndm_ifindex = neigh->dev->ifindex;
2444
2445         if (nla_put(skb, NDA_DST, neigh->tbl->key_len, neigh->primary_key))
2446                 goto nla_put_failure;
2447
2448         read_lock_bh(&neigh->lock);
2449         ndm->ndm_state   = neigh->nud_state;
2450         if (neigh->nud_state & NUD_VALID) {
2451                 char haddr[MAX_ADDR_LEN];
2452
2453                 neigh_ha_snapshot(haddr, neigh, neigh->dev);
2454                 if (nla_put(skb, NDA_LLADDR, neigh->dev->addr_len, haddr) < 0) {
2455                         read_unlock_bh(&neigh->lock);
2456                         goto nla_put_failure;
2457                 }
2458         }
2459
2460         ci.ndm_used      = jiffies_to_clock_t(now - neigh->used);
2461         ci.ndm_confirmed = jiffies_to_clock_t(now - neigh->confirmed);
2462         ci.ndm_updated   = jiffies_to_clock_t(now - neigh->updated);
2463         ci.ndm_refcnt    = refcount_read(&neigh->refcnt) - 1;
2464         read_unlock_bh(&neigh->lock);
2465
2466         if (nla_put_u32(skb, NDA_PROBES, atomic_read(&neigh->probes)) ||
2467             nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
2468                 goto nla_put_failure;
2469
2470         if (neigh->protocol && nla_put_u8(skb, NDA_PROTOCOL, neigh->protocol))
2471                 goto nla_put_failure;
2472
2473         nlmsg_end(skb, nlh);
2474         return 0;
2475
2476 nla_put_failure:
2477         nlmsg_cancel(skb, nlh);
2478         return -EMSGSIZE;
2479 }
2480
2481 static int pneigh_fill_info(struct sk_buff *skb, struct pneigh_entry *pn,
2482                             u32 pid, u32 seq, int type, unsigned int flags,
2483                             struct neigh_table *tbl)
2484 {
2485         struct nlmsghdr *nlh;
2486         struct ndmsg *ndm;
2487
2488         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
2489         if (nlh == NULL)
2490                 return -EMSGSIZE;
2491
2492         ndm = nlmsg_data(nlh);
2493         ndm->ndm_family  = tbl->family;
2494         ndm->ndm_pad1    = 0;
2495         ndm->ndm_pad2    = 0;
2496         ndm->ndm_flags   = pn->flags | NTF_PROXY;
2497         ndm->ndm_type    = RTN_UNICAST;
2498         ndm->ndm_ifindex = pn->dev ? pn->dev->ifindex : 0;
2499         ndm->ndm_state   = NUD_NONE;
2500
2501         if (nla_put(skb, NDA_DST, tbl->key_len, pn->key))
2502                 goto nla_put_failure;
2503
2504         if (pn->protocol && nla_put_u8(skb, NDA_PROTOCOL, pn->protocol))
2505                 goto nla_put_failure;
2506
2507         nlmsg_end(skb, nlh);
2508         return 0;
2509
2510 nla_put_failure:
2511         nlmsg_cancel(skb, nlh);
2512         return -EMSGSIZE;
2513 }
2514
2515 static void neigh_update_notify(struct neighbour *neigh, u32 nlmsg_pid)
2516 {
2517         call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
2518         __neigh_notify(neigh, RTM_NEWNEIGH, 0, nlmsg_pid);
2519 }
2520
2521 static bool neigh_master_filtered(struct net_device *dev, int master_idx)
2522 {
2523         struct net_device *master;
2524
2525         if (!master_idx)
2526                 return false;
2527
2528         master = dev ? netdev_master_upper_dev_get(dev) : NULL;
2529         if (!master || master->ifindex != master_idx)
2530                 return true;
2531
2532         return false;
2533 }
2534
2535 static bool neigh_ifindex_filtered(struct net_device *dev, int filter_idx)
2536 {
2537         if (filter_idx && (!dev || dev->ifindex != filter_idx))
2538                 return true;
2539
2540         return false;
2541 }
2542
2543 struct neigh_dump_filter {
2544         int master_idx;
2545         int dev_idx;
2546 };
2547
2548 static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
2549                             struct netlink_callback *cb,
2550                             struct neigh_dump_filter *filter)
2551 {
2552         struct net *net = sock_net(skb->sk);
2553         struct neighbour *n;
2554         int rc, h, s_h = cb->args[1];
2555         int idx, s_idx = idx = cb->args[2];
2556         struct neigh_hash_table *nht;
2557         unsigned int flags = NLM_F_MULTI;
2558
2559         if (filter->dev_idx || filter->master_idx)
2560                 flags |= NLM_F_DUMP_FILTERED;
2561
2562         rcu_read_lock_bh();
2563         nht = rcu_dereference_bh(tbl->nht);
2564
2565         for (h = s_h; h < (1 << nht->hash_shift); h++) {
2566                 if (h > s_h)
2567                         s_idx = 0;
2568                 for (n = rcu_dereference_bh(nht->hash_buckets[h]), idx = 0;
2569                      n != NULL;
2570                      n = rcu_dereference_bh(n->next)) {
2571                         if (idx < s_idx || !net_eq(dev_net(n->dev), net))
2572                                 goto next;
2573                         if (neigh_ifindex_filtered(n->dev, filter->dev_idx) ||
2574                             neigh_master_filtered(n->dev, filter->master_idx))
2575                                 goto next;
2576                         if (neigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,
2577                                             cb->nlh->nlmsg_seq,
2578                                             RTM_NEWNEIGH,
2579                                             flags) < 0) {
2580                                 rc = -1;
2581                                 goto out;
2582                         }
2583 next:
2584                         idx++;
2585                 }
2586         }
2587         rc = skb->len;
2588 out:
2589         rcu_read_unlock_bh();
2590         cb->args[1] = h;
2591         cb->args[2] = idx;
2592         return rc;
2593 }
2594
2595 static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
2596                              struct netlink_callback *cb,
2597                              struct neigh_dump_filter *filter)
2598 {
2599         struct pneigh_entry *n;
2600         struct net *net = sock_net(skb->sk);
2601         int rc, h, s_h = cb->args[3];
2602         int idx, s_idx = idx = cb->args[4];
2603         unsigned int flags = NLM_F_MULTI;
2604
2605         if (filter->dev_idx || filter->master_idx)
2606                 flags |= NLM_F_DUMP_FILTERED;
2607
2608         read_lock_bh(&tbl->lock);
2609
2610         for (h = s_h; h <= PNEIGH_HASHMASK; h++) {
2611                 if (h > s_h)
2612                         s_idx = 0;
2613                 for (n = tbl->phash_buckets[h], idx = 0; n; n = n->next) {
2614                         if (idx < s_idx || pneigh_net(n) != net)
2615                                 goto next;
2616                         if (neigh_ifindex_filtered(n->dev, filter->dev_idx) ||
2617                             neigh_master_filtered(n->dev, filter->master_idx))
2618                                 goto next;
2619                         if (pneigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,
2620                                             cb->nlh->nlmsg_seq,
2621                                             RTM_NEWNEIGH, flags, tbl) < 0) {
2622                                 read_unlock_bh(&tbl->lock);
2623                                 rc = -1;
2624                                 goto out;
2625                         }
2626                 next:
2627                         idx++;
2628                 }
2629         }
2630
2631         read_unlock_bh(&tbl->lock);
2632         rc = skb->len;
2633 out:
2634         cb->args[3] = h;
2635         cb->args[4] = idx;
2636         return rc;
2637
2638 }
2639
2640 static int neigh_valid_dump_req(const struct nlmsghdr *nlh,
2641                                 bool strict_check,
2642                                 struct neigh_dump_filter *filter,
2643                                 struct netlink_ext_ack *extack)
2644 {
2645         struct nlattr *tb[NDA_MAX + 1];
2646         int err, i;
2647
2648         if (strict_check) {
2649                 struct ndmsg *ndm;
2650
2651                 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndm))) {
2652                         NL_SET_ERR_MSG(extack, "Invalid header for neighbor dump request");
2653                         return -EINVAL;
2654                 }
2655
2656                 ndm = nlmsg_data(nlh);
2657                 if (ndm->ndm_pad1  || ndm->ndm_pad2  || ndm->ndm_ifindex ||
2658                     ndm->ndm_state || ndm->ndm_type) {
2659                         NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor dump request");
2660                         return -EINVAL;
2661                 }
2662
2663                 if (ndm->ndm_flags & ~NTF_PROXY) {
2664                         NL_SET_ERR_MSG(extack, "Invalid flags in header for neighbor dump request");
2665                         return -EINVAL;
2666                 }
2667
2668                 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct ndmsg),
2669                                                     tb, NDA_MAX, nda_policy,
2670                                                     extack);
2671         } else {
2672                 err = nlmsg_parse_deprecated(nlh, sizeof(struct ndmsg), tb,
2673                                              NDA_MAX, nda_policy, extack);
2674         }
2675         if (err < 0)
2676                 return err;
2677
2678         for (i = 0; i <= NDA_MAX; ++i) {
2679                 if (!tb[i])
2680                         continue;
2681
2682                 /* all new attributes should require strict_check */
2683                 switch (i) {
2684                 case NDA_IFINDEX:
2685                         filter->dev_idx = nla_get_u32(tb[i]);
2686                         break;
2687                 case NDA_MASTER:
2688                         filter->master_idx = nla_get_u32(tb[i]);
2689                         break;
2690                 default:
2691                         if (strict_check) {
2692                                 NL_SET_ERR_MSG(extack, "Unsupported attribute in neighbor dump request");
2693                                 return -EINVAL;
2694                         }
2695                 }
2696         }
2697
2698         return 0;
2699 }
2700
2701 static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2702 {
2703         const struct nlmsghdr *nlh = cb->nlh;
2704         struct neigh_dump_filter filter = {};
2705         struct neigh_table *tbl;
2706         int t, family, s_t;
2707         int proxy = 0;
2708         int err;
2709
2710         family = ((struct rtgenmsg *)nlmsg_data(nlh))->rtgen_family;
2711
2712         /* check for full ndmsg structure presence, family member is
2713          * the same for both structures
2714          */
2715         if (nlmsg_len(nlh) >= sizeof(struct ndmsg) &&
2716             ((struct ndmsg *)nlmsg_data(nlh))->ndm_flags == NTF_PROXY)
2717                 proxy = 1;
2718
2719         err = neigh_valid_dump_req(nlh, cb->strict_check, &filter, cb->extack);
2720         if (err < 0 && cb->strict_check)
2721                 return err;
2722
2723         s_t = cb->args[0];
2724
2725         for (t = 0; t < NEIGH_NR_TABLES; t++) {
2726                 tbl = neigh_tables[t];
2727
2728                 if (!tbl)
2729                         continue;
2730                 if (t < s_t || (family && tbl->family != family))
2731                         continue;
2732                 if (t > s_t)
2733                         memset(&cb->args[1], 0, sizeof(cb->args) -
2734                                                 sizeof(cb->args[0]));
2735                 if (proxy)
2736                         err = pneigh_dump_table(tbl, skb, cb, &filter);
2737                 else
2738                         err = neigh_dump_table(tbl, skb, cb, &filter);
2739                 if (err < 0)
2740                         break;
2741         }
2742
2743         cb->args[0] = t;
2744         return skb->len;
2745 }
2746
2747 static int neigh_valid_get_req(const struct nlmsghdr *nlh,
2748                                struct neigh_table **tbl,
2749                                void **dst, int *dev_idx, u8 *ndm_flags,
2750                                struct netlink_ext_ack *extack)
2751 {
2752         struct nlattr *tb[NDA_MAX + 1];
2753         struct ndmsg *ndm;
2754         int err, i;
2755
2756         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndm))) {
2757                 NL_SET_ERR_MSG(extack, "Invalid header for neighbor get request");
2758                 return -EINVAL;
2759         }
2760
2761         ndm = nlmsg_data(nlh);
2762         if (ndm->ndm_pad1  || ndm->ndm_pad2  || ndm->ndm_state ||
2763             ndm->ndm_type) {
2764                 NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor get request");
2765                 return -EINVAL;
2766         }
2767
2768         if (ndm->ndm_flags & ~NTF_PROXY) {
2769                 NL_SET_ERR_MSG(extack, "Invalid flags in header for neighbor get request");
2770                 return -EINVAL;
2771         }
2772
2773         err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct ndmsg), tb,
2774                                             NDA_MAX, nda_policy, extack);
2775         if (err < 0)
2776                 return err;
2777
2778         *ndm_flags = ndm->ndm_flags;
2779         *dev_idx = ndm->ndm_ifindex;
2780         *tbl = neigh_find_table(ndm->ndm_family);
2781         if (*tbl == NULL) {
2782                 NL_SET_ERR_MSG(extack, "Unsupported family in header for neighbor get request");
2783                 return -EAFNOSUPPORT;
2784         }
2785
2786         for (i = 0; i <= NDA_MAX; ++i) {
2787                 if (!tb[i])
2788                         continue;
2789
2790                 switch (i) {
2791                 case NDA_DST:
2792                         if (nla_len(tb[i]) != (int)(*tbl)->key_len) {
2793                                 NL_SET_ERR_MSG(extack, "Invalid network address in neighbor get request");
2794                                 return -EINVAL;
2795                         }
2796                         *dst = nla_data(tb[i]);
2797                         break;
2798                 default:
2799                         NL_SET_ERR_MSG(extack, "Unsupported attribute in neighbor get request");
2800                         return -EINVAL;
2801                 }
2802         }
2803
2804         return 0;
2805 }
2806
2807 static inline size_t neigh_nlmsg_size(void)
2808 {
2809         return NLMSG_ALIGN(sizeof(struct ndmsg))
2810                + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
2811                + nla_total_size(MAX_ADDR_LEN) /* NDA_LLADDR */
2812                + nla_total_size(sizeof(struct nda_cacheinfo))
2813                + nla_total_size(4)  /* NDA_PROBES */
2814                + nla_total_size(1); /* NDA_PROTOCOL */
2815 }
2816
2817 static int neigh_get_reply(struct net *net, struct neighbour *neigh,
2818                            u32 pid, u32 seq)
2819 {
2820         struct sk_buff *skb;
2821         int err = 0;
2822
2823         skb = nlmsg_new(neigh_nlmsg_size(), GFP_KERNEL);
2824         if (!skb)
2825                 return -ENOBUFS;
2826
2827         err = neigh_fill_info(skb, neigh, pid, seq, RTM_NEWNEIGH, 0);
2828         if (err) {
2829                 kfree_skb(skb);
2830                 goto errout;
2831         }
2832
2833         err = rtnl_unicast(skb, net, pid);
2834 errout:
2835         return err;
2836 }
2837
2838 static inline size_t pneigh_nlmsg_size(void)
2839 {
2840         return NLMSG_ALIGN(sizeof(struct ndmsg))
2841                + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
2842                + nla_total_size(1); /* NDA_PROTOCOL */
2843 }
2844
2845 static int pneigh_get_reply(struct net *net, struct pneigh_entry *neigh,
2846                             u32 pid, u32 seq, struct neigh_table *tbl)
2847 {
2848         struct sk_buff *skb;
2849         int err = 0;
2850
2851         skb = nlmsg_new(pneigh_nlmsg_size(), GFP_KERNEL);
2852         if (!skb)
2853                 return -ENOBUFS;
2854
2855         err = pneigh_fill_info(skb, neigh, pid, seq, RTM_NEWNEIGH, 0, tbl);
2856         if (err) {
2857                 kfree_skb(skb);
2858                 goto errout;
2859         }
2860
2861         err = rtnl_unicast(skb, net, pid);
2862 errout:
2863         return err;
2864 }
2865
2866 static int neigh_get(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2867                      struct netlink_ext_ack *extack)
2868 {
2869         struct net *net = sock_net(in_skb->sk);
2870         struct net_device *dev = NULL;
2871         struct neigh_table *tbl = NULL;
2872         struct neighbour *neigh;
2873         void *dst = NULL;
2874         u8 ndm_flags = 0;
2875         int dev_idx = 0;
2876         int err;
2877
2878         err = neigh_valid_get_req(nlh, &tbl, &dst, &dev_idx, &ndm_flags,
2879                                   extack);
2880         if (err < 0)
2881                 return err;
2882
2883         if (dev_idx) {
2884                 dev = __dev_get_by_index(net, dev_idx);
2885                 if (!dev) {
2886                         NL_SET_ERR_MSG(extack, "Unknown device ifindex");
2887                         return -ENODEV;
2888                 }
2889         }
2890
2891         if (!dst) {
2892                 NL_SET_ERR_MSG(extack, "Network address not specified");
2893                 return -EINVAL;
2894         }
2895
2896         if (ndm_flags & NTF_PROXY) {
2897                 struct pneigh_entry *pn;
2898
2899                 pn = pneigh_lookup(tbl, net, dst, dev, 0);
2900                 if (!pn) {
2901                         NL_SET_ERR_MSG(extack, "Proxy neighbour entry not found");
2902                         return -ENOENT;
2903                 }
2904                 return pneigh_get_reply(net, pn, NETLINK_CB(in_skb).portid,
2905                                         nlh->nlmsg_seq, tbl);
2906         }
2907
2908         if (!dev) {
2909                 NL_SET_ERR_MSG(extack, "No device specified");
2910                 return -EINVAL;
2911         }
2912
2913         neigh = neigh_lookup(tbl, dst, dev);
2914         if (!neigh) {
2915                 NL_SET_ERR_MSG(extack, "Neighbour entry not found");
2916                 return -ENOENT;
2917         }
2918
2919         err = neigh_get_reply(net, neigh, NETLINK_CB(in_skb).portid,
2920                               nlh->nlmsg_seq);
2921
2922         neigh_release(neigh);
2923
2924         return err;
2925 }
2926
2927 void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie)
2928 {
2929         int chain;
2930         struct neigh_hash_table *nht;
2931
2932         rcu_read_lock_bh();
2933         nht = rcu_dereference_bh(tbl->nht);
2934
2935         read_lock(&tbl->lock); /* avoid resizes */
2936         for (chain = 0; chain < (1 << nht->hash_shift); chain++) {
2937                 struct neighbour *n;
2938
2939                 for (n = rcu_dereference_bh(nht->hash_buckets[chain]);
2940                      n != NULL;
2941                      n = rcu_dereference_bh(n->next))
2942                         cb(n, cookie);
2943         }
2944         read_unlock(&tbl->lock);
2945         rcu_read_unlock_bh();
2946 }
2947 EXPORT_SYMBOL(neigh_for_each);
2948
2949 /* The tbl->lock must be held as a writer and BH disabled. */
2950 void __neigh_for_each_release(struct neigh_table *tbl,
2951                               int (*cb)(struct neighbour *))
2952 {
2953         int chain;
2954         struct neigh_hash_table *nht;
2955
2956         nht = rcu_dereference_protected(tbl->nht,
2957                                         lockdep_is_held(&tbl->lock));
2958         for (chain = 0; chain < (1 << nht->hash_shift); chain++) {
2959                 struct neighbour *n;
2960                 struct neighbour __rcu **np;
2961
2962                 np = &nht->hash_buckets[chain];
2963                 while ((n = rcu_dereference_protected(*np,
2964                                         lockdep_is_held(&tbl->lock))) != NULL) {
2965                         int release;
2966
2967                         write_lock(&n->lock);
2968                         release = cb(n);
2969                         if (release) {
2970                                 rcu_assign_pointer(*np,
2971                                         rcu_dereference_protected(n->next,
2972                                                 lockdep_is_held(&tbl->lock)));
2973                                 neigh_mark_dead(n);
2974                         } else
2975                                 np = &n->next;
2976                         write_unlock(&n->lock);
2977                         if (release)
2978                                 neigh_cleanup_and_release(n);
2979                 }
2980         }
2981 }
2982 EXPORT_SYMBOL(__neigh_for_each_release);
2983
2984 int neigh_xmit(int index, struct net_device *dev,
2985                const void *addr, struct sk_buff *skb)
2986 {
2987         int err = -EAFNOSUPPORT;
2988         if (likely(index < NEIGH_NR_TABLES)) {
2989                 struct neigh_table *tbl;
2990                 struct neighbour *neigh;
2991
2992                 tbl = neigh_tables[index];
2993                 if (!tbl)
2994                         goto out;
2995                 rcu_read_lock_bh();
2996                 if (index == NEIGH_ARP_TABLE) {
2997                         u32 key = *((u32 *)addr);
2998
2999                         neigh = __ipv4_neigh_lookup_noref(dev, key);
3000                 } else {
3001                         neigh = __neigh_lookup_noref(tbl, addr, dev);
3002                 }
3003                 if (!neigh)
3004                         neigh = __neigh_create(tbl, addr, dev, false);
3005                 err = PTR_ERR(neigh);
3006                 if (IS_ERR(neigh)) {
3007                         rcu_read_unlock_bh();
3008                         goto out_kfree_skb;
3009                 }
3010                 err = neigh->output(neigh, skb);
3011                 rcu_read_unlock_bh();
3012         }
3013         else if (index == NEIGH_LINK_TABLE) {
3014                 err = dev_hard_header(skb, dev, ntohs(skb->protocol),
3015                                       addr, NULL, skb->len);
3016                 if (err < 0)
3017                         goto out_kfree_skb;
3018                 err = dev_queue_xmit(skb);
3019         }
3020 out:
3021         return err;
3022 out_kfree_skb:
3023         kfree_skb(skb);
3024         goto out;
3025 }
3026 EXPORT_SYMBOL(neigh_xmit);
3027
3028 #ifdef CONFIG_PROC_FS
3029
3030 static struct neighbour *neigh_get_first(struct seq_file *seq)
3031 {
3032         struct neigh_seq_state *state = seq->private;
3033         struct net *net = seq_file_net(seq);
3034         struct neigh_hash_table *nht = state->nht;
3035         struct neighbour *n = NULL;
3036         int bucket;
3037
3038         state->flags &= ~NEIGH_SEQ_IS_PNEIGH;
3039         for (bucket = 0; bucket < (1 << nht->hash_shift); bucket++) {
3040                 n = rcu_dereference_bh(nht->hash_buckets[bucket]);
3041
3042                 while (n) {
3043                         if (!net_eq(dev_net(n->dev), net))
3044                                 goto next;
3045                         if (state->neigh_sub_iter) {
3046                                 loff_t fakep = 0;
3047                                 void *v;
3048
3049                                 v = state->neigh_sub_iter(state, n, &fakep);
3050                                 if (!v)
3051                                         goto next;
3052                         }
3053                         if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
3054                                 break;
3055                         if (n->nud_state & ~NUD_NOARP)
3056                                 break;
3057 next:
3058                         n = rcu_dereference_bh(n->next);
3059                 }
3060
3061                 if (n)
3062                         break;
3063         }
3064         state->bucket = bucket;
3065
3066         return n;
3067 }
3068
3069 static struct neighbour *neigh_get_next(struct seq_file *seq,
3070                                         struct neighbour *n,
3071                                         loff_t *pos)
3072 {
3073         struct neigh_seq_state *state = seq->private;
3074         struct net *net = seq_file_net(seq);
3075         struct neigh_hash_table *nht = state->nht;
3076
3077         if (state->neigh_sub_iter) {
3078                 void *v = state->neigh_sub_iter(state, n, pos);
3079                 if (v)
3080                         return n;
3081         }
3082         n = rcu_dereference_bh(n->next);
3083
3084         while (1) {
3085                 while (n) {
3086                         if (!net_eq(dev_net(n->dev), net))
3087                                 goto next;
3088                         if (state->neigh_sub_iter) {
3089                                 void *v = state->neigh_sub_iter(state, n, pos);
3090                                 if (v)
3091                                         return n;
3092                                 goto next;
3093                         }
3094                         if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
3095                                 break;
3096
3097                         if (n->nud_state & ~NUD_NOARP)
3098                                 break;
3099 next:
3100                         n = rcu_dereference_bh(n->next);
3101                 }
3102
3103                 if (n)
3104                         break;
3105
3106                 if (++state->bucket >= (1 << nht->hash_shift))
3107                         break;
3108
3109                 n = rcu_dereference_bh(nht->hash_buckets[state->bucket]);
3110         }
3111
3112         if (n && pos)
3113                 --(*pos);
3114         return n;
3115 }
3116
3117 static struct neighbour *neigh_get_idx(struct seq_file *seq, loff_t *pos)
3118 {
3119         struct neighbour *n = neigh_get_first(seq);
3120
3121         if (n) {
3122                 --(*pos);
3123                 while (*pos) {
3124                         n = neigh_get_next(seq, n, pos);
3125                         if (!n)
3126                                 break;
3127                 }
3128         }
3129         return *pos ? NULL : n;
3130 }
3131
3132 static struct pneigh_entry *pneigh_get_first(struct seq_file *seq)
3133 {
3134         struct neigh_seq_state *state = seq->private;
3135         struct net *net = seq_file_net(seq);
3136         struct neigh_table *tbl = state->tbl;
3137         struct pneigh_entry *pn = NULL;
3138         int bucket = state->bucket;
3139
3140         state->flags |= NEIGH_SEQ_IS_PNEIGH;
3141         for (bucket = 0; bucket <= PNEIGH_HASHMASK; bucket++) {
3142                 pn = tbl->phash_buckets[bucket];
3143                 while (pn && !net_eq(pneigh_net(pn), net))
3144                         pn = pn->next;
3145                 if (pn)
3146                         break;
3147         }
3148         state->bucket = bucket;
3149
3150         return pn;
3151 }
3152
3153 static struct pneigh_entry *pneigh_get_next(struct seq_file *seq,
3154                                             struct pneigh_entry *pn,
3155                                             loff_t *pos)
3156 {
3157         struct neigh_seq_state *state = seq->private;
3158         struct net *net = seq_file_net(seq);
3159         struct neigh_table *tbl = state->tbl;
3160
3161         do {
3162                 pn = pn->next;
3163         } while (pn && !net_eq(pneigh_net(pn), net));
3164
3165         while (!pn) {
3166                 if (++state->bucket > PNEIGH_HASHMASK)
3167                         break;
3168                 pn = tbl->phash_buckets[state->bucket];
3169                 while (pn && !net_eq(pneigh_net(pn), net))
3170                         pn = pn->next;
3171                 if (pn)
3172                         break;
3173         }
3174
3175         if (pn && pos)
3176                 --(*pos);
3177
3178         return pn;
3179 }
3180
3181 static struct pneigh_entry *pneigh_get_idx(struct seq_file *seq, loff_t *pos)
3182 {
3183         struct pneigh_entry *pn = pneigh_get_first(seq);
3184
3185         if (pn) {
3186                 --(*pos);
3187                 while (*pos) {
3188                         pn = pneigh_get_next(seq, pn, pos);
3189                         if (!pn)
3190                                 break;
3191                 }
3192         }
3193         return *pos ? NULL : pn;
3194 }
3195
3196 static void *neigh_get_idx_any(struct seq_file *seq, loff_t *pos)
3197 {
3198         struct neigh_seq_state *state = seq->private;
3199         void *rc;
3200         loff_t idxpos = *pos;
3201
3202         rc = neigh_get_idx(seq, &idxpos);
3203         if (!rc && !(state->flags & NEIGH_SEQ_NEIGH_ONLY))
3204                 rc = pneigh_get_idx(seq, &idxpos);
3205
3206         return rc;
3207 }
3208
3209 void *neigh_seq_start(struct seq_file *seq, loff_t *pos, struct neigh_table *tbl, unsigned int neigh_seq_flags)
3210         __acquires(tbl->lock)
3211         __acquires(rcu_bh)
3212 {
3213         struct neigh_seq_state *state = seq->private;
3214
3215         state->tbl = tbl;
3216         state->bucket = 0;
3217         state->flags = (neigh_seq_flags & ~NEIGH_SEQ_IS_PNEIGH);
3218
3219         rcu_read_lock_bh();
3220         state->nht = rcu_dereference_bh(tbl->nht);
3221         read_lock(&tbl->lock);
3222
3223         return *pos ? neigh_get_idx_any(seq, pos) : SEQ_START_TOKEN;
3224 }
3225 EXPORT_SYMBOL(neigh_seq_start);
3226
3227 void *neigh_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3228 {
3229         struct neigh_seq_state *state;
3230         void *rc;
3231
3232         if (v == SEQ_START_TOKEN) {
3233                 rc = neigh_get_first(seq);
3234                 goto out;
3235         }
3236
3237         state = seq->private;
3238         if (!(state->flags & NEIGH_SEQ_IS_PNEIGH)) {
3239                 rc = neigh_get_next(seq, v, NULL);
3240                 if (rc)
3241                         goto out;
3242                 if (!(state->flags & NEIGH_SEQ_NEIGH_ONLY))
3243                         rc = pneigh_get_first(seq);
3244         } else {
3245                 BUG_ON(state->flags & NEIGH_SEQ_NEIGH_ONLY);
3246                 rc = pneigh_get_next(seq, v, NULL);
3247         }
3248 out:
3249         ++(*pos);
3250         return rc;
3251 }
3252 EXPORT_SYMBOL(neigh_seq_next);
3253
3254 void neigh_seq_stop(struct seq_file *seq, void *v)
3255         __releases(tbl->lock)
3256         __releases(rcu_bh)
3257 {
3258         struct neigh_seq_state *state = seq->private;
3259         struct neigh_table *tbl = state->tbl;
3260
3261         read_unlock(&tbl->lock);
3262         rcu_read_unlock_bh();
3263 }
3264 EXPORT_SYMBOL(neigh_seq_stop);
3265
3266 /* statistics via seq_file */
3267
3268 static void *neigh_stat_seq_start(struct seq_file *seq, loff_t *pos)
3269 {
3270         struct neigh_table *tbl = PDE_DATA(file_inode(seq->file));
3271         int cpu;
3272
3273         if (*pos == 0)
3274                 return SEQ_START_TOKEN;
3275
3276         for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
3277                 if (!cpu_possible(cpu))
3278                         continue;
3279                 *pos = cpu+1;
3280                 return per_cpu_ptr(tbl->stats, cpu);
3281         }
3282         return NULL;
3283 }
3284
3285 static void *neigh_stat_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3286 {
3287         struct neigh_table *tbl = PDE_DATA(file_inode(seq->file));
3288         int cpu;
3289
3290         for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
3291                 if (!cpu_possible(cpu))
3292                         continue;
3293                 *pos = cpu+1;
3294                 return per_cpu_ptr(tbl->stats, cpu);
3295         }
3296         return NULL;
3297 }
3298
3299 static void neigh_stat_seq_stop(struct seq_file *seq, void *v)
3300 {
3301
3302 }
3303
3304 static int neigh_stat_seq_show(struct seq_file *seq, void *v)
3305 {
3306         struct neigh_table *tbl = PDE_DATA(file_inode(seq->file));
3307         struct neigh_statistics *st = v;
3308
3309         if (v == SEQ_START_TOKEN) {
3310                 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 table_fulls\n");
3311                 return 0;
3312         }
3313
3314         seq_printf(seq, "%08x  %08lx %08lx %08lx  %08lx %08lx  %08lx  "
3315                         "%08lx %08lx  %08lx %08lx %08lx %08lx\n",
3316                    atomic_read(&tbl->entries),
3317
3318                    st->allocs,
3319                    st->destroys,
3320                    st->hash_grows,
3321
3322                    st->lookups,
3323                    st->hits,
3324
3325                    st->res_failed,
3326
3327                    st->rcv_probes_mcast,
3328                    st->rcv_probes_ucast,
3329
3330                    st->periodic_gc_runs,
3331                    st->forced_gc_runs,
3332                    st->unres_discards,
3333                    st->table_fulls
3334                    );
3335
3336         return 0;
3337 }
3338
3339 static const struct seq_operations neigh_stat_seq_ops = {
3340         .start  = neigh_stat_seq_start,
3341         .next   = neigh_stat_seq_next,
3342         .stop   = neigh_stat_seq_stop,
3343         .show   = neigh_stat_seq_show,
3344 };
3345 #endif /* CONFIG_PROC_FS */
3346
3347 static void __neigh_notify(struct neighbour *n, int type, int flags,
3348                            u32 pid)
3349 {
3350         struct net *net = dev_net(n->dev);
3351         struct sk_buff *skb;
3352         int err = -ENOBUFS;
3353
3354         skb = nlmsg_new(neigh_nlmsg_size(), GFP_ATOMIC);
3355         if (skb == NULL)
3356                 goto errout;
3357
3358         err = neigh_fill_info(skb, n, pid, 0, type, flags);
3359         if (err < 0) {
3360                 /* -EMSGSIZE implies BUG in neigh_nlmsg_size() */
3361                 WARN_ON(err == -EMSGSIZE);
3362                 kfree_skb(skb);
3363                 goto errout;
3364         }
3365         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
3366         return;
3367 errout:
3368         if (err < 0)
3369                 rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
3370 }
3371
3372 void neigh_app_ns(struct neighbour *n)
3373 {
3374         __neigh_notify(n, RTM_GETNEIGH, NLM_F_REQUEST, 0);
3375 }
3376 EXPORT_SYMBOL(neigh_app_ns);
3377
3378 #ifdef CONFIG_SYSCTL
3379 static int unres_qlen_max = INT_MAX / SKB_TRUESIZE(ETH_FRAME_LEN);
3380
3381 static int proc_unres_qlen(struct ctl_table *ctl, int write,
3382                            void __user *buffer, size_t *lenp, loff_t *ppos)
3383 {
3384         int size, ret;
3385         struct ctl_table tmp = *ctl;
3386
3387         tmp.extra1 = SYSCTL_ZERO;
3388         tmp.extra2 = &unres_qlen_max;
3389         tmp.data = &size;
3390
3391         size = *(int *)ctl->data / SKB_TRUESIZE(ETH_FRAME_LEN);
3392         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
3393
3394         if (write && !ret)
3395                 *(int *)ctl->data = size * SKB_TRUESIZE(ETH_FRAME_LEN);
3396         return ret;
3397 }
3398
3399 static struct neigh_parms *neigh_get_dev_parms_rcu(struct net_device *dev,
3400                                                    int family)
3401 {
3402         switch (family) {
3403         case AF_INET:
3404                 return __in_dev_arp_parms_get_rcu(dev);
3405         case AF_INET6:
3406                 return __in6_dev_nd_parms_get_rcu(dev);
3407         }
3408         return NULL;
3409 }
3410
3411 static void neigh_copy_dflt_parms(struct net *net, struct neigh_parms *p,
3412                                   int index)
3413 {
3414         struct net_device *dev;
3415         int family = neigh_parms_family(p);
3416
3417         rcu_read_lock();
3418         for_each_netdev_rcu(net, dev) {
3419                 struct neigh_parms *dst_p =
3420                                 neigh_get_dev_parms_rcu(dev, family);
3421
3422                 if (dst_p && !test_bit(index, dst_p->data_state))
3423                         dst_p->data[index] = p->data[index];
3424         }
3425         rcu_read_unlock();
3426 }
3427
3428 static void neigh_proc_update(struct ctl_table *ctl, int write)
3429 {
3430         struct net_device *dev = ctl->extra1;
3431         struct neigh_parms *p = ctl->extra2;
3432         struct net *net = neigh_parms_net(p);
3433         int index = (int *) ctl->data - p->data;
3434
3435         if (!write)
3436                 return;
3437
3438         set_bit(index, p->data_state);
3439         if (index == NEIGH_VAR_DELAY_PROBE_TIME)
3440                 call_netevent_notifiers(NETEVENT_DELAY_PROBE_TIME_UPDATE, p);
3441         if (!dev) /* NULL dev means this is default value */
3442                 neigh_copy_dflt_parms(net, p, index);
3443 }
3444
3445 static int neigh_proc_dointvec_zero_intmax(struct ctl_table *ctl, int write,
3446                                            void __user *buffer,
3447                                            size_t *lenp, loff_t *ppos)
3448 {
3449         struct ctl_table tmp = *ctl;
3450         int ret;
3451
3452         tmp.extra1 = SYSCTL_ZERO;
3453         tmp.extra2 = SYSCTL_INT_MAX;
3454
3455         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
3456         neigh_proc_update(ctl, write);
3457         return ret;
3458 }
3459
3460 int neigh_proc_dointvec(struct ctl_table *ctl, int write,
3461                         void __user *buffer, size_t *lenp, loff_t *ppos)
3462 {
3463         int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
3464
3465         neigh_proc_update(ctl, write);
3466         return ret;
3467 }
3468 EXPORT_SYMBOL(neigh_proc_dointvec);
3469
3470 int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
3471                                 void __user *buffer,
3472                                 size_t *lenp, loff_t *ppos)
3473 {
3474         int ret = proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos);
3475
3476         neigh_proc_update(ctl, write);
3477         return ret;
3478 }
3479 EXPORT_SYMBOL(neigh_proc_dointvec_jiffies);
3480
3481 static int neigh_proc_dointvec_userhz_jiffies(struct ctl_table *ctl, int write,
3482                                               void __user *buffer,
3483                                               size_t *lenp, loff_t *ppos)
3484 {
3485         int ret = proc_dointvec_userhz_jiffies(ctl, write, buffer, lenp, ppos);
3486
3487         neigh_proc_update(ctl, write);
3488         return ret;
3489 }
3490
3491 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
3492                                    void __user *buffer,
3493                                    size_t *lenp, loff_t *ppos)
3494 {
3495         int ret = proc_dointvec_ms_jiffies(ctl, write, buffer, lenp, ppos);
3496
3497         neigh_proc_update(ctl, write);
3498         return ret;
3499 }
3500 EXPORT_SYMBOL(neigh_proc_dointvec_ms_jiffies);
3501
3502 static int neigh_proc_dointvec_unres_qlen(struct ctl_table *ctl, int write,
3503                                           void __user *buffer,
3504                                           size_t *lenp, loff_t *ppos)
3505 {
3506         int ret = proc_unres_qlen(ctl, write, buffer, lenp, ppos);
3507
3508         neigh_proc_update(ctl, write);
3509         return ret;
3510 }
3511
3512 static int neigh_proc_base_reachable_time(struct ctl_table *ctl, int write,
3513                                           void __user *buffer,
3514                                           size_t *lenp, loff_t *ppos)
3515 {
3516         struct neigh_parms *p = ctl->extra2;
3517         int ret;
3518
3519         if (strcmp(ctl->procname, "base_reachable_time") == 0)
3520                 ret = neigh_proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos);
3521         else if (strcmp(ctl->procname, "base_reachable_time_ms") == 0)
3522                 ret = neigh_proc_dointvec_ms_jiffies(ctl, write, buffer, lenp, ppos);
3523         else
3524                 ret = -1;
3525
3526         if (write && ret == 0) {
3527                 /* update reachable_time as well, otherwise, the change will
3528                  * only be effective after the next time neigh_periodic_work
3529                  * decides to recompute it
3530                  */
3531                 p->reachable_time =
3532                         neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
3533         }
3534         return ret;
3535 }
3536
3537 #define NEIGH_PARMS_DATA_OFFSET(index)  \
3538         (&((struct neigh_parms *) 0)->data[index])
3539
3540 #define NEIGH_SYSCTL_ENTRY(attr, data_attr, name, mval, proc) \
3541         [NEIGH_VAR_ ## attr] = { \
3542                 .procname       = name, \
3543                 .data           = NEIGH_PARMS_DATA_OFFSET(NEIGH_VAR_ ## data_attr), \
3544                 .maxlen         = sizeof(int), \
3545                 .mode           = mval, \
3546                 .proc_handler   = proc, \
3547         }
3548
3549 #define NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(attr, name) \
3550         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_zero_intmax)
3551
3552 #define NEIGH_SYSCTL_JIFFIES_ENTRY(attr, name) \
3553         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_jiffies)
3554
3555 #define NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(attr, name) \
3556         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_userhz_jiffies)
3557
3558 #define NEIGH_SYSCTL_MS_JIFFIES_ENTRY(attr, name) \
3559         NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_ms_jiffies)
3560
3561 #define NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(attr, data_attr, name) \
3562         NEIGH_SYSCTL_ENTRY(attr, data_attr, name, 0644, neigh_proc_dointvec_ms_jiffies)
3563
3564 #define NEIGH_SYSCTL_UNRES_QLEN_REUSED_ENTRY(attr, data_attr, name) \
3565         NEIGH_SYSCTL_ENTRY(attr, data_attr, name, 0644, neigh_proc_dointvec_unres_qlen)
3566
3567 static struct neigh_sysctl_table {
3568         struct ctl_table_header *sysctl_header;
3569         struct ctl_table neigh_vars[NEIGH_VAR_MAX + 1];
3570 } neigh_sysctl_template __read_mostly = {
3571         .neigh_vars = {
3572                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(MCAST_PROBES, "mcast_solicit"),
3573                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(UCAST_PROBES, "ucast_solicit"),
3574                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(APP_PROBES, "app_solicit"),
3575                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(MCAST_REPROBES, "mcast_resolicit"),
3576                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(RETRANS_TIME, "retrans_time"),
3577                 NEIGH_SYSCTL_JIFFIES_ENTRY(BASE_REACHABLE_TIME, "base_reachable_time"),
3578                 NEIGH_SYSCTL_JIFFIES_ENTRY(DELAY_PROBE_TIME, "delay_first_probe_time"),
3579                 NEIGH_SYSCTL_JIFFIES_ENTRY(GC_STALETIME, "gc_stale_time"),
3580                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(QUEUE_LEN_BYTES, "unres_qlen_bytes"),
3581                 NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(PROXY_QLEN, "proxy_qlen"),
3582                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(ANYCAST_DELAY, "anycast_delay"),
3583                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(PROXY_DELAY, "proxy_delay"),
3584                 NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(LOCKTIME, "locktime"),
3585                 NEIGH_SYSCTL_UNRES_QLEN_REUSED_ENTRY(QUEUE_LEN, QUEUE_LEN_BYTES, "unres_qlen"),
3586                 NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(RETRANS_TIME_MS, RETRANS_TIME, "retrans_time_ms"),
3587                 NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(BASE_REACHABLE_TIME_MS, BASE_REACHABLE_TIME, "base_reachable_time_ms"),
3588                 [NEIGH_VAR_GC_INTERVAL] = {
3589                         .procname       = "gc_interval",
3590                         .maxlen         = sizeof(int),
3591                         .mode           = 0644,
3592                         .proc_handler   = proc_dointvec_jiffies,
3593                 },
3594                 [NEIGH_VAR_GC_THRESH1] = {
3595                         .procname       = "gc_thresh1",
3596                         .maxlen         = sizeof(int),
3597                         .mode           = 0644,
3598                         .extra1         = SYSCTL_ZERO,
3599                         .extra2         = SYSCTL_INT_MAX,
3600                         .proc_handler   = proc_dointvec_minmax,
3601                 },
3602                 [NEIGH_VAR_GC_THRESH2] = {
3603                         .procname       = "gc_thresh2",
3604                         .maxlen         = sizeof(int),
3605                         .mode           = 0644,
3606                         .extra1         = SYSCTL_ZERO,
3607                         .extra2         = SYSCTL_INT_MAX,
3608                         .proc_handler   = proc_dointvec_minmax,
3609                 },
3610                 [NEIGH_VAR_GC_THRESH3] = {
3611                         .procname       = "gc_thresh3",
3612                         .maxlen         = sizeof(int),
3613                         .mode           = 0644,
3614                         .extra1         = SYSCTL_ZERO,
3615                         .extra2         = SYSCTL_INT_MAX,
3616                         .proc_handler   = proc_dointvec_minmax,
3617                 },
3618                 {},
3619         },
3620 };
3621
3622 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
3623                           proc_handler *handler)
3624 {
3625         int i;
3626         struct neigh_sysctl_table *t;
3627         const char *dev_name_source;
3628         char neigh_path[ sizeof("net//neigh/") + IFNAMSIZ + IFNAMSIZ ];
3629         char *p_name;
3630
3631         t = kmemdup(&neigh_sysctl_template, sizeof(*t), GFP_KERNEL);
3632         if (!t)
3633                 goto err;
3634
3635         for (i = 0; i < NEIGH_VAR_GC_INTERVAL; i++) {
3636                 t->neigh_vars[i].data += (long) p;
3637                 t->neigh_vars[i].extra1 = dev;
3638                 t->neigh_vars[i].extra2 = p;
3639         }
3640
3641         if (dev) {
3642                 dev_name_source = dev->name;
3643                 /* Terminate the table early */
3644                 memset(&t->neigh_vars[NEIGH_VAR_GC_INTERVAL], 0,
3645                        sizeof(t->neigh_vars[NEIGH_VAR_GC_INTERVAL]));
3646         } else {
3647                 struct neigh_table *tbl = p->tbl;
3648                 dev_name_source = "default";
3649                 t->neigh_vars[NEIGH_VAR_GC_INTERVAL].data = &tbl->gc_interval;
3650                 t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = &tbl->gc_thresh1;
3651                 t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = &tbl->gc_thresh2;
3652                 t->neigh_vars[NEIGH_VAR_GC_THRESH3].data = &tbl->gc_thresh3;
3653         }
3654
3655         if (handler) {
3656                 /* RetransTime */
3657                 t->neigh_vars[NEIGH_VAR_RETRANS_TIME].proc_handler = handler;
3658                 /* ReachableTime */
3659                 t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].proc_handler = handler;
3660                 /* RetransTime (in milliseconds)*/
3661                 t->neigh_vars[NEIGH_VAR_RETRANS_TIME_MS].proc_handler = handler;
3662                 /* ReachableTime (in milliseconds) */
3663                 t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].proc_handler = handler;
3664         } else {
3665                 /* Those handlers will update p->reachable_time after
3666                  * base_reachable_time(_ms) is set to ensure the new timer starts being
3667                  * applied after the next neighbour update instead of waiting for
3668                  * neigh_periodic_work to update its value (can be multiple minutes)
3669                  * So any handler that replaces them should do this as well
3670                  */
3671                 /* ReachableTime */
3672                 t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].proc_handler =
3673                         neigh_proc_base_reachable_time;
3674                 /* ReachableTime (in milliseconds) */
3675                 t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].proc_handler =
3676                         neigh_proc_base_reachable_time;
3677         }
3678
3679         /* Don't export sysctls to unprivileged users */
3680         if (neigh_parms_net(p)->user_ns != &init_user_ns)
3681                 t->neigh_vars[0].procname = NULL;
3682
3683         switch (neigh_parms_family(p)) {
3684         case AF_INET:
3685               p_name = "ipv4";
3686               break;
3687         case AF_INET6:
3688               p_name = "ipv6";
3689               break;
3690         default:
3691               BUG();
3692         }
3693
3694         snprintf(neigh_path, sizeof(neigh_path), "net/%s/neigh/%s",
3695                 p_name, dev_name_source);
3696         t->sysctl_header =
3697                 register_net_sysctl(neigh_parms_net(p), neigh_path, t->neigh_vars);
3698         if (!t->sysctl_header)
3699                 goto free;
3700
3701         p->sysctl_table = t;
3702         return 0;
3703
3704 free:
3705         kfree(t);
3706 err:
3707         return -ENOBUFS;
3708 }
3709 EXPORT_SYMBOL(neigh_sysctl_register);
3710
3711 void neigh_sysctl_unregister(struct neigh_parms *p)
3712 {
3713         if (p->sysctl_table) {
3714                 struct neigh_sysctl_table *t = p->sysctl_table;
3715                 p->sysctl_table = NULL;
3716                 unregister_net_sysctl_table(t->sysctl_header);
3717                 kfree(t);
3718         }
3719 }
3720 EXPORT_SYMBOL(neigh_sysctl_unregister);
3721
3722 #endif  /* CONFIG_SYSCTL */
3723
3724 static int __init neigh_init(void)
3725 {
3726         rtnl_register(PF_UNSPEC, RTM_NEWNEIGH, neigh_add, NULL, 0);
3727         rtnl_register(PF_UNSPEC, RTM_DELNEIGH, neigh_delete, NULL, 0);
3728         rtnl_register(PF_UNSPEC, RTM_GETNEIGH, neigh_get, neigh_dump_info, 0);
3729
3730         rtnl_register(PF_UNSPEC, RTM_GETNEIGHTBL, NULL, neightbl_dump_info,
3731                       0);
3732         rtnl_register(PF_UNSPEC, RTM_SETNEIGHTBL, neightbl_set, NULL, 0);
3733
3734         return 0;
3735 }
3736
3737 subsys_initcall(neigh_init);