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   1 /*
   2  *      Generic address resolution entity
   3  *
   4  *      Authors:
   5  *      Pedro Roque             <roque@di.fc.ul.pt>
   6  *      Alexey Kuznetsov        <kuznet@ms2.inr.ac.ru>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  *
  13  *      Fixes:
  14  *      Vitaly E. Lavrov        releasing NULL neighbor in neigh_add.
  15  *      Harald Welte            Add neighbour cache statistics like rtstat
  16  */
  17
  18 #include <linux/types.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/socket.h>
  22 #include <linux/sched.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/proc_fs.h>
  25 #ifdef CONFIG_SYSCTL
  26 #include <linux/sysctl.h>
  27 #endif
  28 #include <linux/times.h>
  29 #include <net/neighbour.h>
  30 #include <net/dst.h>
  31 #include <net/sock.h>
  32 #include <net/netevent.h>
  33 #include <net/netlink.h>
  34 #include <linux/rtnetlink.h>
  35 #include <linux/random.h>
  36 #include <linux/string.h>
  37
  38 #define NEIGH_DEBUG 1
  39
  40 #define NEIGH_PRINTK(x...) printk(x)
  41 #define NEIGH_NOPRINTK(x...) do { ; } while(0)
  42 #define NEIGH_PRINTK0 NEIGH_PRINTK
  43 #define NEIGH_PRINTK1 NEIGH_NOPRINTK
  44 #define NEIGH_PRINTK2 NEIGH_NOPRINTK
  45
  46 #if NEIGH_DEBUG >= 1
  47 #undef NEIGH_PRINTK1
  48 #define NEIGH_PRINTK1 NEIGH_PRINTK
  49 #endif
  50 #if NEIGH_DEBUG >= 2
  51 #undef NEIGH_PRINTK2
  52 #define NEIGH_PRINTK2 NEIGH_PRINTK
  53 #endif
  54
  55 #define PNEIGH_HASHMASK         0xF
  56
  57 static void neigh_timer_handler(unsigned long arg);
  58 #ifdef CONFIG_ARPD
  59 static void neigh_app_notify(struct neighbour *n);
  60 #endif
  61 static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
  62 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
  63
  64 static struct neigh_table *neigh_tables;
  65 #ifdef CONFIG_PROC_FS
  66 static struct file_operations neigh_stat_seq_fops;
  67 #endif
  68
  69 /*
  70    Neighbour hash table buckets are protected with rwlock tbl->lock.
  71
  72    - All the scans/updates to hash buckets MUST be made under this lock.
  73    - NOTHING clever should be made under this lock: no callbacks
  74      to protocol backends, no attempts to send something to network.
  75      It will result in deadlocks, if backend/driver wants to use neighbour
  76      cache.
  77    - If the entry requires some non-trivial actions, increase
  78      its reference count and release table lock.
  79
  80    Neighbour entries are protected:
  81    - with reference count.
  82    - with rwlock neigh->lock
  83
  84    Reference count prevents destruction.
  85
  86    neigh->lock mainly serializes ll address data and its validity state.
  87    However, the same lock is used to protect another entry fields:
  88     - timer
  89     - resolution queue
  90
  91    Again, nothing clever shall be made under neigh->lock,
  92    the most complicated procedure, which we allow is dev->hard_header.
  93    It is supposed, that dev->hard_header is simplistic and does
  94    not make callbacks to neighbour tables.
  95
  96    The last lock is neigh_tbl_lock. It is pure SMP lock, protecting
  97    list of neighbour tables. This list is used only in process context,
  98  */
  99
 100 static DEFINE_RWLOCK(neigh_tbl_lock);
 101
 102 static int neigh_blackhole(struct sk_buff *skb)
 103 {
 104         kfree_skb(skb);
 105         return -ENETDOWN;
 106 }
 107
 108 /*
 109  * It is random distribution in the interval (1/2)*base...(3/2)*base.
 110  * It corresponds to default IPv6 settings and is not overridable,
 111  * because it is really reasonable choice.
 112  */
 113
 114 unsigned long neigh_rand_reach_time(unsigned long base)
 115 {
 116         return (base ? (net_random() % base) + (base >> 1) : 0);
 117 }
 118
 119
 120 static int neigh_forced_gc(struct neigh_table *tbl)
 121 {
 122         int shrunk = 0;
 123         int i;
 124
 125         NEIGH_CACHE_STAT_INC(tbl, forced_gc_runs);
 126
 127         write_lock_bh(&tbl->lock);
 128         for (i = 0; i <= tbl->hash_mask; i++) {
 129                 struct neighbour *n, **np;
 130
 131                 np = &tbl->hash_buckets[i];
 132                 while ((n = *np) != NULL) {
 133                         /* Neighbour record may be discarded if:
 134                          * - nobody refers to it.
 135                          * - it is not permanent
 136                          */
 137                         write_lock(&n->lock);
 138                         if (atomic_read(&n->refcnt) == 1 &&
 139                             !(n->nud_state & NUD_PERMANENT)) {
 140                                 *np     = n->next;
 141                                 n->dead = 1;
 142                                 shrunk  = 1;
 143                                 write_unlock(&n->lock);
 144                                 neigh_release(n);
 145                                 continue;
 146                         }
 147                         write_unlock(&n->lock);
 148                         np = &n->next;
 149                 }
 150         }
 151
 152         tbl->last_flush = jiffies;
 153
 154         write_unlock_bh(&tbl->lock);
 155
 156         return shrunk;
 157 }
 158
 159 static int neigh_del_timer(struct neighbour *n)
 160 {
 161         if ((n->nud_state & NUD_IN_TIMER) &&
 162             del_timer(&n->timer)) {
 163                 neigh_release(n);
 164                 return 1;
 165         }
 166         return 0;
 167 }
 168
 169 static void pneigh_queue_purge(struct sk_buff_head *list)
 170 {
 171         struct sk_buff *skb;
 172
 173         while ((skb = skb_dequeue(list)) != NULL) {
 174                 dev_put(skb->dev);
 175                 kfree_skb(skb);
 176         }
 177 }
 178
 179 static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev)
 180 {
 181         int i;
 182
 183         for (i = 0; i <= tbl->hash_mask; i++) {
 184                 struct neighbour *n, **np = &tbl->hash_buckets[i];
 185
 186                 while ((n = *np) != NULL) {
 187                         if (dev && n->dev != dev) {
 188                                 np = &n->next;
 189                                 continue;
 190                         }
 191                         *np = n->next;
 192                         write_lock(&n->lock);
 193                         neigh_del_timer(n);
 194                         n->dead = 1;
 195
 196                         if (atomic_read(&n->refcnt) != 1) {
 197                                 /* The most unpleasant situation.
 198                                    We must destroy neighbour entry,
 199                                    but someone still uses it.
 200
 201                                    The destroy will be delayed until
 202                                    the last user releases us, but
 203                                    we must kill timers etc. and move
 204                                    it to safe state.
 205                                  */
 206                                 skb_queue_purge(&n->arp_queue);
 207                                 n->output = neigh_blackhole;
 208                                 if (n->nud_state & NUD_VALID)
 209                                         n->nud_state = NUD_NOARP;
 210                                 else
 211                                         n->nud_state = NUD_NONE;
 212                                 NEIGH_PRINTK2("neigh %p is stray.\n", n);
 213                         }
 214                         write_unlock(&n->lock);
 215                         neigh_release(n);
 216                 }
 217         }
 218 }
 219
 220 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev)
 221 {
 222         write_lock_bh(&tbl->lock);
 223         neigh_flush_dev(tbl, dev);
 224         write_unlock_bh(&tbl->lock);
 225 }
 226
 227 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 228 {
 229         write_lock_bh(&tbl->lock);
 230         neigh_flush_dev(tbl, dev);
 231         pneigh_ifdown(tbl, dev);
 232         write_unlock_bh(&tbl->lock);
 233
 234         del_timer_sync(&tbl->proxy_timer);
 235         pneigh_queue_purge(&tbl->proxy_queue);
 236         return 0;
 237 }
 238
 239 static struct neighbour *neigh_alloc(struct neigh_table *tbl)
 240 {
 241         struct neighbour *n = NULL;
 242         unsigned long now = jiffies;
 243         int entries;
 244
 245         entries = atomic_inc_return(&tbl->entries) - 1;
 246         if (entries >= tbl->gc_thresh3 ||
 247             (entries >= tbl->gc_thresh2 &&
 248              time_after(now, tbl->last_flush + 5 * HZ))) {
 249                 if (!neigh_forced_gc(tbl) &&
 250                     entries >= tbl->gc_thresh3)
 251                         goto out_entries;
 252         }
 253
 254         n = kmem_cache_alloc(tbl->kmem_cachep, SLAB_ATOMIC);
 255         if (!n)
 256                 goto out_entries;
 257
 258         memset(n, 0, tbl->entry_size);
 259
 260         skb_queue_head_init(&n->arp_queue);
 261         rwlock_init(&n->lock);
 262         n->updated        = n->used = now;
 263         n->nud_state      = NUD_NONE;
 264         n->output         = neigh_blackhole;
 265         n->parms          = neigh_parms_clone(&tbl->parms);
 266         init_timer(&n->timer);
 267         n->timer.function = neigh_timer_handler;
 268         n->timer.data     = (unsigned long)n;
 269
 270         NEIGH_CACHE_STAT_INC(tbl, allocs);
 271         n->tbl            = tbl;
 272         atomic_set(&n->refcnt, 1);
 273         n->dead           = 1;
 274 out:
 275         return n;
 276
 277 out_entries:
 278         atomic_dec(&tbl->entries);
 279         goto out;
 280 }
 281
 282 static struct neighbour **neigh_hash_alloc(unsigned int entries)
 283 {
 284         unsigned long size = entries * sizeof(struct neighbour *);
 285         struct neighbour **ret;
 286
 287         if (size <= PAGE_SIZE) {
 288                 ret = kzalloc(size, GFP_ATOMIC);
 289         } else {
 290                 ret = (struct neighbour **)
 291                       __get_free_pages(GFP_ATOMIC|__GFP_ZERO, get_order(size));
 292         }
 293         return ret;
 294 }
 295
 296 static void neigh_hash_free(struct neighbour **hash, unsigned int entries)
 297 {
 298         unsigned long size = entries * sizeof(struct neighbour *);
 299
 300         if (size <= PAGE_SIZE)
 301                 kfree(hash);
 302         else
 303                 free_pages((unsigned long)hash, get_order(size));
 304 }
 305
 306 static void neigh_hash_grow(struct neigh_table *tbl, unsigned long new_entries)
 307 {
 308         struct neighbour **new_hash, **old_hash;
 309         unsigned int i, new_hash_mask, old_entries;
 310
 311         NEIGH_CACHE_STAT_INC(tbl, hash_grows);
 312
 313         BUG_ON(new_entries & (new_entries - 1));
 314         new_hash = neigh_hash_alloc(new_entries);
 315         if (!new_hash)
 316                 return;
 317
 318         old_entries = tbl->hash_mask + 1;
 319         new_hash_mask = new_entries - 1;
 320         old_hash = tbl->hash_buckets;
 321
 322         get_random_bytes(&tbl->hash_rnd, sizeof(tbl->hash_rnd));
 323         for (i = 0; i < old_entries; i++) {
 324                 struct neighbour *n, *next;
 325
 326                 for (n = old_hash[i]; n; n = next) {
 327                         unsigned int hash_val = tbl->hash(n->primary_key, n->dev);
 328
 329                         hash_val &= new_hash_mask;
 330                         next = n->next;
 331
 332                         n->next = new_hash[hash_val];
 333                         new_hash[hash_val] = n;
 334                 }
 335         }
 336         tbl->hash_buckets = new_hash;
 337         tbl->hash_mask = new_hash_mask;
 338
 339         neigh_hash_free(old_hash, old_entries);
 340 }
 341
 342 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
 343                                struct net_device *dev)
 344 {
 345         struct neighbour *n;
 346         int key_len = tbl->key_len;
 347         u32 hash_val = tbl->hash(pkey, dev) & tbl->hash_mask;
 348
 349         NEIGH_CACHE_STAT_INC(tbl, lookups);
 350
 351         read_lock_bh(&tbl->lock);
 352         for (n = tbl->hash_buckets[hash_val]; n; n = n->next) {
 353                 if (dev == n->dev && !memcmp(n->primary_key, pkey, key_len)) {
 354                         neigh_hold(n);
 355                         NEIGH_CACHE_STAT_INC(tbl, hits);
 356                         break;
 357                 }
 358         }
 359         read_unlock_bh(&tbl->lock);
 360         return n;
 361 }
 362
 363 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, const void *pkey)
 364 {
 365         struct neighbour *n;
 366         int key_len = tbl->key_len;
 367         u32 hash_val = tbl->hash(pkey, NULL) & tbl->hash_mask;
 368
 369         NEIGH_CACHE_STAT_INC(tbl, lookups);
 370
 371         read_lock_bh(&tbl->lock);
 372         for (n = tbl->hash_buckets[hash_val]; n; n = n->next) {
 373                 if (!memcmp(n->primary_key, pkey, key_len)) {
 374                         neigh_hold(n);
 375                         NEIGH_CACHE_STAT_INC(tbl, hits);
 376                         break;
 377                 }
 378         }
 379         read_unlock_bh(&tbl->lock);
 380         return n;
 381 }
 382
 383 struct neighbour *neigh_create(struct neigh_table *tbl, const void *pkey,
 384                                struct net_device *dev)
 385 {
 386         u32 hash_val;
 387         int key_len = tbl->key_len;
 388         int error;
 389         struct neighbour *n1, *rc, *n = neigh_alloc(tbl);
 390
 391         if (!n) {
 392                 rc = ERR_PTR(-ENOBUFS);
 393                 goto out;
 394         }
 395
 396         memcpy(n->primary_key, pkey, key_len);
 397         n->dev = dev;
 398         dev_hold(dev);
 399
 400         /* Protocol specific setup. */
 401         if (tbl->constructor && (error = tbl->constructor(n)) < 0) {
 402                 rc = ERR_PTR(error);
 403                 goto out_neigh_release;
 404         }
 405
 406         /* Device specific setup. */
 407         if (n->parms->neigh_setup &&
 408             (error = n->parms->neigh_setup(n)) < 0) {
 409                 rc = ERR_PTR(error);
 410                 goto out_neigh_release;
 411         }
 412
 413         n->confirmed = jiffies - (n->parms->base_reachable_time << 1);
 414
 415         write_lock_bh(&tbl->lock);
 416
 417         if (atomic_read(&tbl->entries) > (tbl->hash_mask + 1))
 418                 neigh_hash_grow(tbl, (tbl->hash_mask + 1) << 1);
 419
 420         hash_val = tbl->hash(pkey, dev) & tbl->hash_mask;
 421
 422         if (n->parms->dead) {
 423                 rc = ERR_PTR(-EINVAL);
 424                 goto out_tbl_unlock;
 425         }
 426
 427         for (n1 = tbl->hash_buckets[hash_val]; n1; n1 = n1->next) {
 428                 if (dev == n1->dev && !memcmp(n1->primary_key, pkey, key_len)) {
 429                         neigh_hold(n1);
 430                         rc = n1;
 431                         goto out_tbl_unlock;
 432                 }
 433         }
 434
 435         n->next = tbl->hash_buckets[hash_val];
 436         tbl->hash_buckets[hash_val] = n;
 437         n->dead = 0;
 438         neigh_hold(n);
 439         write_unlock_bh(&tbl->lock);
 440         NEIGH_PRINTK2("neigh %p is created.\n", n);
 441         rc = n;
 442 out:
 443         return rc;
 444 out_tbl_unlock:
 445         write_unlock_bh(&tbl->lock);
 446 out_neigh_release:
 447         neigh_release(n);
 448         goto out;
 449 }
 450
 451 struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl, const void *pkey,
 452                                     struct net_device *dev, int creat)
 453 {
 454         struct pneigh_entry *n;
 455         int key_len = tbl->key_len;
 456         u32 hash_val = *(u32 *)(pkey + key_len - 4);
 457
 458         hash_val ^= (hash_val >> 16);
 459         hash_val ^= hash_val >> 8;
 460         hash_val ^= hash_val >> 4;
 461         hash_val &= PNEIGH_HASHMASK;
 462
 463         read_lock_bh(&tbl->lock);
 464
 465         for (n = tbl->phash_buckets[hash_val]; n; n = n->next) {
 466                 if (!memcmp(n->key, pkey, key_len) &&
 467                     (n->dev == dev || !n->dev)) {
 468                         read_unlock_bh(&tbl->lock);
 469                         goto out;
 470                 }
 471         }
 472         read_unlock_bh(&tbl->lock);
 473         n = NULL;
 474         if (!creat)
 475                 goto out;
 476
 477         n = kmalloc(sizeof(*n) + key_len, GFP_KERNEL);
 478         if (!n)
 479                 goto out;
 480
 481         memcpy(n->key, pkey, key_len);
 482         n->dev = dev;
 483         if (dev)
 484                 dev_hold(dev);
 485
 486         if (tbl->pconstructor && tbl->pconstructor(n)) {
 487                 if (dev)
 488                         dev_put(dev);
 489                 kfree(n);
 490                 n = NULL;
 491                 goto out;
 492         }
 493
 494         write_lock_bh(&tbl->lock);
 495         n->next = tbl->phash_buckets[hash_val];
 496         tbl->phash_buckets[hash_val] = n;
 497         write_unlock_bh(&tbl->lock);
 498 out:
 499         return n;
 500 }
 501
 502
 503 int pneigh_delete(struct neigh_table *tbl, const void *pkey,
 504                   struct net_device *dev)
 505 {
 506         struct pneigh_entry *n, **np;
 507         int key_len = tbl->key_len;
 508         u32 hash_val = *(u32 *)(pkey + key_len - 4);
 509
 510         hash_val ^= (hash_val >> 16);
 511         hash_val ^= hash_val >> 8;
 512         hash_val ^= hash_val >> 4;
 513         hash_val &= PNEIGH_HASHMASK;
 514
 515         write_lock_bh(&tbl->lock);
 516         for (np = &tbl->phash_buckets[hash_val]; (n = *np) != NULL;
 517              np = &n->next) {
 518                 if (!memcmp(n->key, pkey, key_len) && n->dev == dev) {
 519                         *np = n->next;
 520                         write_unlock_bh(&tbl->lock);
 521                         if (tbl->pdestructor)
 522                                 tbl->pdestructor(n);
 523                         if (n->dev)
 524                                 dev_put(n->dev);
 525                         kfree(n);
 526                         return 0;
 527                 }
 528         }
 529         write_unlock_bh(&tbl->lock);
 530         return -ENOENT;
 531 }
 532
 533 static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 534 {
 535         struct pneigh_entry *n, **np;
 536         u32 h;
 537
 538         for (h = 0; h <= PNEIGH_HASHMASK; h++) {
 539                 np = &tbl->phash_buckets[h];
 540                 while ((n = *np) != NULL) {
 541                         if (!dev || n->dev == dev) {
 542                                 *np = n->next;
 543                                 if (tbl->pdestructor)
 544                                         tbl->pdestructor(n);
 545                                 if (n->dev)
 546                                         dev_put(n->dev);
 547                                 kfree(n);
 548                                 continue;
 549                         }
 550                         np = &n->next;
 551                 }
 552         }
 553         return -ENOENT;
 554 }
 555
 556
 557 /*
 558  *      neighbour must already be out of the table;
 559  *
 560  */
 561 void neigh_destroy(struct neighbour *neigh)
 562 {
 563         struct hh_cache *hh;
 564
 565         NEIGH_CACHE_STAT_INC(neigh->tbl, destroys);
 566
 567         if (!neigh->dead) {
 568                 printk(KERN_WARNING
 569                        "Destroying alive neighbour %p\n", neigh);
 570                 dump_stack();
 571                 return;
 572         }
 573
 574         if (neigh_del_timer(neigh))
 575                 printk(KERN_WARNING "Impossible event.\n");
 576
 577         while ((hh = neigh->hh) != NULL) {
 578                 neigh->hh = hh->hh_next;
 579                 hh->hh_next = NULL;
 580                 write_lock_bh(&hh->hh_lock);
 581                 hh->hh_output = neigh_blackhole;
 582                 write_unlock_bh(&hh->hh_lock);
 583                 if (atomic_dec_and_test(&hh->hh_refcnt))
 584                         kfree(hh);
 585         }
 586
 587         if (neigh->parms->neigh_destructor)
 588                 (neigh->parms->neigh_destructor)(neigh);
 589
 590         skb_queue_purge(&neigh->arp_queue);
 591
 592         dev_put(neigh->dev);
 593         neigh_parms_put(neigh->parms);
 594
 595         NEIGH_PRINTK2("neigh %p is destroyed.\n", neigh);
 596
 597         atomic_dec(&neigh->tbl->entries);
 598         kmem_cache_free(neigh->tbl->kmem_cachep, neigh);
 599 }
 600
 601 /* Neighbour state is suspicious;
 602    disable fast path.
 603
 604    Called with write_locked neigh.
 605  */
 606 static void neigh_suspect(struct neighbour *neigh)
 607 {
 608         struct hh_cache *hh;
 609
 610         NEIGH_PRINTK2("neigh %p is suspected.\n", neigh);
 611
 612         neigh->output = neigh->ops->output;
 613
 614         for (hh = neigh->hh; hh; hh = hh->hh_next)
 615                 hh->hh_output = neigh->ops->output;
 616 }
 617
 618 /* Neighbour state is OK;
 619    enable fast path.
 620
 621    Called with write_locked neigh.
 622  */
 623 static void neigh_connect(struct neighbour *neigh)
 624 {
 625         struct hh_cache *hh;
 626
 627         NEIGH_PRINTK2("neigh %p is connected.\n", neigh);
 628
 629         neigh->output = neigh->ops->connected_output;
 630
 631         for (hh = neigh->hh; hh; hh = hh->hh_next)
 632                 hh->hh_output = neigh->ops->hh_output;
 633 }
 634
 635 static void neigh_periodic_timer(unsigned long arg)
 636 {
 637         struct neigh_table *tbl = (struct neigh_table *)arg;
 638         struct neighbour *n, **np;
 639         unsigned long expire, now = jiffies;
 640
 641         NEIGH_CACHE_STAT_INC(tbl, periodic_gc_runs);
 642
 643         write_lock(&tbl->lock);
 644
 645         /*
 646          *      periodically recompute ReachableTime from random function
 647          */
 648
 649         if (time_after(now, tbl->last_rand + 300 * HZ)) {
 650                 struct neigh_parms *p;
 651                 tbl->last_rand = now;
 652                 for (p = &tbl->parms; p; p = p->next)
 653                         p->reachable_time =
 654                                 neigh_rand_reach_time(p->base_reachable_time);
 655         }
 656
 657         np = &tbl->hash_buckets[tbl->hash_chain_gc];
 658         tbl->hash_chain_gc = ((tbl->hash_chain_gc + 1) & tbl->hash_mask);
 659
 660         while ((n = *np) != NULL) {
 661                 unsigned int state;
 662
 663                 write_lock(&n->lock);
 664
 665                 state = n->nud_state;
 666                 if (state & (NUD_PERMANENT | NUD_IN_TIMER)) {
 667                         write_unlock(&n->lock);
 668                         goto next_elt;
 669                 }
 670
 671                 if (time_before(n->used, n->confirmed))
 672                         n->used = n->confirmed;
 673
 674                 if (atomic_read(&n->refcnt) == 1 &&
 675                     (state == NUD_FAILED ||
 676                      time_after(now, n->used + n->parms->gc_staletime))) {
 677                         *np = n->next;
 678                         n->dead = 1;
 679                         write_unlock(&n->lock);
 680                         neigh_release(n);
 681                         continue;
 682                 }
 683                 write_unlock(&n->lock);
 684
 685 next_elt:
 686                 np = &n->next;
 687         }
 688
 689         /* Cycle through all hash buckets every base_reachable_time/2 ticks.
 690          * ARP entry timeouts range from 1/2 base_reachable_time to 3/2
 691          * base_reachable_time.
 692          */
 693         expire = tbl->parms.base_reachable_time >> 1;
 694         expire /= (tbl->hash_mask + 1);
 695         if (!expire)
 696                 expire = 1;
 697
 698         mod_timer(&tbl->gc_timer, now + expire);
 699
 700         write_unlock(&tbl->lock);
 701 }
 702
 703 static __inline__ int neigh_max_probes(struct neighbour *n)
 704 {
 705         struct neigh_parms *p = n->parms;
 706         return (n->nud_state & NUD_PROBE ?
 707                 p->ucast_probes :
 708                 p->ucast_probes + p->app_probes + p->mcast_probes);
 709 }
 710
 711 static inline void neigh_add_timer(struct neighbour *n, unsigned long when)
 712 {
 713         if (unlikely(mod_timer(&n->timer, when))) {
 714                 printk("NEIGH: BUG, double timer add, state is %x\n",
 715                        n->nud_state);
 716                 dump_stack();
 717         }
 718 }
 719
 720 /* Called when a timer expires for a neighbour entry. */
 721
 722 static void neigh_timer_handler(unsigned long arg)
 723 {
 724         unsigned long now, next;
 725         struct neighbour *neigh = (struct neighbour *)arg;
 726         unsigned state;
 727         int notify = 0;
 728
 729         write_lock(&neigh->lock);
 730
 731         state = neigh->nud_state;
 732         now = jiffies;
 733         next = now + HZ;
 734
 735         if (!(state & NUD_IN_TIMER)) {
 736 #ifndef CONFIG_SMP
 737                 printk(KERN_WARNING "neigh: timer & !nud_in_timer\n");
 738 #endif
 739                 goto out;
 740         }
 741
 742         if (state & NUD_REACHABLE) {
 743                 if (time_before_eq(now,
 744                                    neigh->confirmed + neigh->parms->reachable_time)) {
 745                         NEIGH_PRINTK2("neigh %p is still alive.\n", neigh);
 746                         next = neigh->confirmed + neigh->parms->reachable_time;
 747                 } else if (time_before_eq(now,
 748                                           neigh->used + neigh->parms->delay_probe_time)) {
 749                         NEIGH_PRINTK2("neigh %p is delayed.\n", neigh);
 750                         neigh->nud_state = NUD_DELAY;
 751                         neigh->updated = jiffies;
 752                         neigh_suspect(neigh);
 753                         next = now + neigh->parms->delay_probe_time;
 754                 } else {
 755                         NEIGH_PRINTK2("neigh %p is suspected.\n", neigh);
 756                         neigh->nud_state = NUD_STALE;
 757                         neigh->updated = jiffies;
 758                         neigh_suspect(neigh);
 759                         notify = 1;
 760                 }
 761         } else if (state & NUD_DELAY) {
 762                 if (time_before_eq(now,
 763                                    neigh->confirmed + neigh->parms->delay_probe_time)) {
 764                         NEIGH_PRINTK2("neigh %p is now reachable.\n", neigh);
 765                         neigh->nud_state = NUD_REACHABLE;
 766                         neigh->updated = jiffies;
 767                         neigh_connect(neigh);
 768                         notify = 1;
 769                         next = neigh->confirmed + neigh->parms->reachable_time;
 770                 } else {
 771                         NEIGH_PRINTK2("neigh %p is probed.\n", neigh);
 772                         neigh->nud_state = NUD_PROBE;
 773                         neigh->updated = jiffies;
 774                         atomic_set(&neigh->probes, 0);
 775                         next = now + neigh->parms->retrans_time;
 776                 }
 777         } else {
 778                 /* NUD_PROBE|NUD_INCOMPLETE */
 779                 next = now + neigh->parms->retrans_time;
 780         }
 781
 782         if ((neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) &&
 783             atomic_read(&neigh->probes) >= neigh_max_probes(neigh)) {
 784                 struct sk_buff *skb;
 785
 786                 neigh->nud_state = NUD_FAILED;
 787                 neigh->updated = jiffies;
 788                 notify = 1;
 789                 NEIGH_CACHE_STAT_INC(neigh->tbl, res_failed);
 790                 NEIGH_PRINTK2("neigh %p is failed.\n", neigh);
 791
 792                 /* It is very thin place. report_unreachable is very complicated
 793                    routine. Particularly, it can hit the same neighbour entry!
 794
 795                    So that, we try to be accurate and avoid dead loop. --ANK
 796                  */
 797                 while (neigh->nud_state == NUD_FAILED &&
 798                        (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
 799                         write_unlock(&neigh->lock);
 800                         neigh->ops->error_report(neigh, skb);
 801                         write_lock(&neigh->lock);
 802                 }
 803                 skb_queue_purge(&neigh->arp_queue);
 804         }
 805
 806         if (neigh->nud_state & NUD_IN_TIMER) {
 807                 if (time_before(next, jiffies + HZ/2))
 808                         next = jiffies + HZ/2;
 809                 if (!mod_timer(&neigh->timer, next))
 810                         neigh_hold(neigh);
 811         }
 812         if (neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) {
 813                 struct sk_buff *skb = skb_peek(&neigh->arp_queue);
 814                 /* keep skb alive even if arp_queue overflows */
 815                 if (skb)
 816                         skb_get(skb);
 817                 write_unlock(&neigh->lock);
 818                 neigh->ops->solicit(neigh, skb);
 819                 atomic_inc(&neigh->probes);
 820                 if (skb)
 821                         kfree_skb(skb);
 822         } else {
 823 out:
 824                 write_unlock(&neigh->lock);
 825         }
 826         if (notify)
 827                 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
 828
 829 #ifdef CONFIG_ARPD
 830         if (notify && neigh->parms->app_probes)
 831                 neigh_app_notify(neigh);
 832 #endif
 833         neigh_release(neigh);
 834 }
 835
 836 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 837 {
 838         int rc;
 839         unsigned long now;
 840
 841         write_lock_bh(&neigh->lock);
 842
 843         rc = 0;
 844         if (neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE))
 845                 goto out_unlock_bh;
 846
 847         now = jiffies;
 848
 849         if (!(neigh->nud_state & (NUD_STALE | NUD_INCOMPLETE))) {
 850                 if (neigh->parms->mcast_probes + neigh->parms->app_probes) {
 851                         atomic_set(&neigh->probes, neigh->parms->ucast_probes);
 852                         neigh->nud_state     = NUD_INCOMPLETE;
 853                         neigh->updated = jiffies;
 854                         neigh_hold(neigh);
 855                         neigh_add_timer(neigh, now + 1);
 856                 } else {
 857                         neigh->nud_state = NUD_FAILED;
 858                         neigh->updated = jiffies;
 859                         write_unlock_bh(&neigh->lock);
 860
 861                         if (skb)
 862                                 kfree_skb(skb);
 863                         return 1;
 864                 }
 865         } else if (neigh->nud_state & NUD_STALE) {
 866                 NEIGH_PRINTK2("neigh %p is delayed.\n", neigh);
 867                 neigh_hold(neigh);
 868                 neigh->nud_state = NUD_DELAY;
 869                 neigh->updated = jiffies;
 870                 neigh_add_timer(neigh,
 871                                 jiffies + neigh->parms->delay_probe_time);
 872         }
 873
 874         if (neigh->nud_state == NUD_INCOMPLETE) {
 875                 if (skb) {
 876                         if (skb_queue_len(&neigh->arp_queue) >=
 877                             neigh->parms->queue_len) {
 878                                 struct sk_buff *buff;
 879                                 buff = neigh->arp_queue.next;
 880                                 __skb_unlink(buff, &neigh->arp_queue);
 881                                 kfree_skb(buff);
 882                         }
 883                         __skb_queue_tail(&neigh->arp_queue, skb);
 884                 }
 885                 rc = 1;
 886         }
 887 out_unlock_bh:
 888         write_unlock_bh(&neigh->lock);
 889         return rc;
 890 }
 891
 892 static void neigh_update_hhs(struct neighbour *neigh)
 893 {
 894         struct hh_cache *hh;
 895         void (*update)(struct hh_cache*, struct net_device*, unsigned char *) =
 896                 neigh->dev->header_cache_update;
 897
 898         if (update) {
 899                 for (hh = neigh->hh; hh; hh = hh->hh_next) {
 900                         write_lock_bh(&hh->hh_lock);
 901                         update(hh, neigh->dev, neigh->ha);
 902                         write_unlock_bh(&hh->hh_lock);
 903                 }
 904         }
 905 }
 906
 907
 908
 909 /* Generic update routine.
 910    -- lladdr is new lladdr or NULL, if it is not supplied.
 911    -- new    is new state.
 912    -- flags
 913         NEIGH_UPDATE_F_OVERRIDE allows to override existing lladdr,
 914                                 if it is different.
 915         NEIGH_UPDATE_F_WEAK_OVERRIDE will suspect existing "connected"
 916                                 lladdr instead of overriding it
 917                                 if it is different.
 918                                 It also allows to retain current state
 919                                 if lladdr is unchanged.
 920         NEIGH_UPDATE_F_ADMIN    means that the change is administrative.
 921
 922         NEIGH_UPDATE_F_OVERRIDE_ISROUTER allows to override existing
 923                                 NTF_ROUTER flag.
 924         NEIGH_UPDATE_F_ISROUTER indicates if the neighbour is known as
 925                                 a router.
 926
 927    Caller MUST hold reference count on the entry.
 928  */
 929
 930 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
 931                  u32 flags)
 932 {
 933         u8 old;
 934         int err;
 935         int notify = 0;
 936         struct net_device *dev;
 937         int update_isrouter = 0;
 938
 939         write_lock_bh(&neigh->lock);
 940
 941         dev    = neigh->dev;
 942         old    = neigh->nud_state;
 943         err    = -EPERM;
 944
 945         if (!(flags & NEIGH_UPDATE_F_ADMIN) &&
 946             (old & (NUD_NOARP | NUD_PERMANENT)))
 947                 goto out;
 948
 949         if (!(new & NUD_VALID)) {
 950                 neigh_del_timer(neigh);
 951                 if (old & NUD_CONNECTED)
 952                         neigh_suspect(neigh);
 953                 neigh->nud_state = new;
 954                 err = 0;
 955                 notify = old & NUD_VALID;
 956                 goto out;
 957         }
 958
 959         /* Compare new lladdr with cached one */
 960         if (!dev->addr_len) {
 961                 /* First case: device needs no address. */
 962                 lladdr = neigh->ha;
 963         } else if (lladdr) {
 964                 /* The second case: if something is already cached
 965                    and a new address is proposed:
 966                    - compare new & old
 967                    - if they are different, check override flag
 968                  */
 969                 if ((old & NUD_VALID) &&
 970                     !memcmp(lladdr, neigh->ha, dev->addr_len))
 971                         lladdr = neigh->ha;
 972         } else {
 973                 /* No address is supplied; if we know something,
 974                    use it, otherwise discard the request.
 975                  */
 976                 err = -EINVAL;
 977                 if (!(old & NUD_VALID))
 978                         goto out;
 979                 lladdr = neigh->ha;
 980         }
 981
 982         if (new & NUD_CONNECTED)
 983                 neigh->confirmed = jiffies;
 984         neigh->updated = jiffies;
 985
 986         /* If entry was valid and address is not changed,
 987            do not change entry state, if new one is STALE.
 988          */
 989         err = 0;
 990         update_isrouter = flags & NEIGH_UPDATE_F_OVERRIDE_ISROUTER;
 991         if (old & NUD_VALID) {
 992                 if (lladdr != neigh->ha && !(flags & NEIGH_UPDATE_F_OVERRIDE)) {
 993                         update_isrouter = 0;
 994                         if ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) &&
 995                             (old & NUD_CONNECTED)) {
 996                                 lladdr = neigh->ha;
 997                                 new = NUD_STALE;
 998                         } else
 999                                 goto out;
1000                 } else {
1001                         if (lladdr == neigh->ha && new == NUD_STALE &&
1002                             ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) ||
1003                              (old & NUD_CONNECTED))
1004                             )
1005                                 new = old;
1006                 }
1007         }
1008
1009         if (new != old) {
1010                 neigh_del_timer(neigh);
1011                 if (new & NUD_IN_TIMER) {
1012                         neigh_hold(neigh);
1013                         neigh_add_timer(neigh, (jiffies +
1014                                                 ((new & NUD_REACHABLE) ?
1015                                                  neigh->parms->reachable_time :
1016                                                  0)));
1017                 }
1018                 neigh->nud_state = new;
1019         }
1020
1021         if (lladdr != neigh->ha) {
1022                 memcpy(&neigh->ha, lladdr, dev->addr_len);
1023                 neigh_update_hhs(neigh);
1024                 if (!(new & NUD_CONNECTED))
1025                         neigh->confirmed = jiffies -
1026                                       (neigh->parms->base_reachable_time << 1);
1027                 notify = 1;
1028         }
1029         if (new == old)
1030                 goto out;
1031         if (new & NUD_CONNECTED)
1032                 neigh_connect(neigh);
1033         else
1034                 neigh_suspect(neigh);
1035         if (!(old & NUD_VALID)) {
1036                 struct sk_buff *skb;
1037
1038                 /* Again: avoid dead loop if something went wrong */
1039
1040                 while (neigh->nud_state & NUD_VALID &&
1041                        (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
1042                         struct neighbour *n1 = neigh;
1043                         write_unlock_bh(&neigh->lock);
1044                         /* On shaper/eql skb->dst->neighbour != neigh :( */
1045                         if (skb->dst && skb->dst->neighbour)
1046                                 n1 = skb->dst->neighbour;
1047                         n1->output(skb);
1048                         write_lock_bh(&neigh->lock);
1049                 }
1050                 skb_queue_purge(&neigh->arp_queue);
1051         }
1052 out:
1053         if (update_isrouter) {
1054                 neigh->flags = (flags & NEIGH_UPDATE_F_ISROUTER) ?
1055                         (neigh->flags | NTF_ROUTER) :
1056                         (neigh->flags & ~NTF_ROUTER);
1057         }
1058         write_unlock_bh(&neigh->lock);
1059
1060         if (notify)
1061                 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
1062 #ifdef CONFIG_ARPD
1063         if (notify && neigh->parms->app_probes)
1064                 neigh_app_notify(neigh);
1065 #endif
1066         return err;
1067 }
1068
1069 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
1070                                  u8 *lladdr, void *saddr,
1071                                  struct net_device *dev)
1072 {
1073         struct neighbour *neigh = __neigh_lookup(tbl, saddr, dev,
1074                                                  lladdr || !dev->addr_len);
1075         if (neigh)
1076                 neigh_update(neigh, lladdr, NUD_STALE,
1077                              NEIGH_UPDATE_F_OVERRIDE);
1078         return neigh;
1079 }
1080
1081 static void neigh_hh_init(struct neighbour *n, struct dst_entry *dst,
1082                           u16 protocol)
1083 {
1084         struct hh_cache *hh;
1085         struct net_device *dev = dst->dev;
1086
1087         for (hh = n->hh; hh; hh = hh->hh_next)
1088                 if (hh->hh_type == protocol)
1089                         break;
1090
1091         if (!hh && (hh = kzalloc(sizeof(*hh), GFP_ATOMIC)) != NULL) {
1092                 rwlock_init(&hh->hh_lock);
1093                 hh->hh_type = protocol;
1094                 atomic_set(&hh->hh_refcnt, 0);
1095                 hh->hh_next = NULL;
1096                 if (dev->hard_header_cache(n, hh)) {
1097                         kfree(hh);
1098                         hh = NULL;
1099                 } else {
1100                         atomic_inc(&hh->hh_refcnt);
1101                         hh->hh_next = n->hh;
1102                         n->hh       = hh;
1103                         if (n->nud_state & NUD_CONNECTED)
1104                                 hh->hh_output = n->ops->hh_output;
1105                         else
1106                                 hh->hh_output = n->ops->output;
1107                 }
1108         }
1109         if (hh) {
1110                 atomic_inc(&hh->hh_refcnt);
1111                 dst->hh = hh;
1112         }
1113 }
1114
1115 /* This function can be used in contexts, where only old dev_queue_xmit
1116    worked, f.e. if you want to override normal output path (eql, shaper),
1117    but resolution is not made yet.
1118  */
1119
1120 int neigh_compat_output(struct sk_buff *skb)
1121 {
1122         struct net_device *dev = skb->dev;
1123
1124         __skb_pull(skb, skb->nh.raw - skb->data);
1125
1126         if (dev->hard_header &&
1127             dev->hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
1128                              skb->len) < 0 &&
1129             dev->rebuild_header(skb))
1130                 return 0;
1131
1132         return dev_queue_xmit(skb);
1133 }
1134
1135 /* Slow and careful. */
1136
1137 int neigh_resolve_output(struct sk_buff *skb)
1138 {
1139         struct dst_entry *dst = skb->dst;
1140         struct neighbour *neigh;
1141         int rc = 0;
1142
1143         if (!dst || !(neigh = dst->neighbour))
1144                 goto discard;
1145
1146         __skb_pull(skb, skb->nh.raw - skb->data);
1147
1148         if (!neigh_event_send(neigh, skb)) {
1149                 int err;
1150                 struct net_device *dev = neigh->dev;
1151                 if (dev->hard_header_cache && !dst->hh) {
1152                         write_lock_bh(&neigh->lock);
1153                         if (!dst->hh)
1154                                 neigh_hh_init(neigh, dst, dst->ops->protocol);
1155                         err = dev->hard_header(skb, dev, ntohs(skb->protocol),
1156                                                neigh->ha, NULL, skb->len);
1157                         write_unlock_bh(&neigh->lock);
1158                 } else {
1159                         read_lock_bh(&neigh->lock);
1160                         err = dev->hard_header(skb, dev, ntohs(skb->protocol),
1161                                                neigh->ha, NULL, skb->len);
1162                         read_unlock_bh(&neigh->lock);
1163                 }
1164                 if (err >= 0)
1165                         rc = neigh->ops->queue_xmit(skb);
1166                 else
1167                         goto out_kfree_skb;
1168         }
1169 out:
1170         return rc;
1171 discard:
1172         NEIGH_PRINTK1("neigh_resolve_output: dst=%p neigh=%p\n",
1173                       dst, dst ? dst->neighbour : NULL);
1174 out_kfree_skb:
1175         rc = -EINVAL;
1176         kfree_skb(skb);
1177         goto out;
1178 }
1179
1180 /* As fast as possible without hh cache */
1181
1182 int neigh_connected_output(struct sk_buff *skb)
1183 {
1184         int err;
1185         struct dst_entry *dst = skb->dst;
1186         struct neighbour *neigh = dst->neighbour;
1187         struct net_device *dev = neigh->dev;
1188
1189         __skb_pull(skb, skb->nh.raw - skb->data);
1190
1191         read_lock_bh(&neigh->lock);
1192         err = dev->hard_header(skb, dev, ntohs(skb->protocol),
1193                                neigh->ha, NULL, skb->len);
1194         read_unlock_bh(&neigh->lock);
1195         if (err >= 0)
1196                 err = neigh->ops->queue_xmit(skb);
1197         else {
1198                 err = -EINVAL;
1199                 kfree_skb(skb);
1200         }
1201         return err;
1202 }
1203
1204 static void neigh_proxy_process(unsigned long arg)
1205 {
1206         struct neigh_table *tbl = (struct neigh_table *)arg;
1207         long sched_next = 0;
1208         unsigned long now = jiffies;
1209         struct sk_buff *skb;
1210
1211         spin_lock(&tbl->proxy_queue.lock);
1212
1213         skb = tbl->proxy_queue.next;
1214
1215         while (skb != (struct sk_buff *)&tbl->proxy_queue) {
1216                 struct sk_buff *back = skb;
1217                 long tdif = NEIGH_CB(back)->sched_next - now;
1218
1219                 skb = skb->next;
1220                 if (tdif <= 0) {
1221                         struct net_device *dev = back->dev;
1222                         __skb_unlink(back, &tbl->proxy_queue);
1223                         if (tbl->proxy_redo && netif_running(dev))
1224                                 tbl->proxy_redo(back);
1225                         else
1226                                 kfree_skb(back);
1227
1228                         dev_put(dev);
1229                 } else if (!sched_next || tdif < sched_next)
1230                         sched_next = tdif;
1231         }
1232         del_timer(&tbl->proxy_timer);
1233         if (sched_next)
1234                 mod_timer(&tbl->proxy_timer, jiffies + sched_next);
1235         spin_unlock(&tbl->proxy_queue.lock);
1236 }
1237
1238 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
1239                     struct sk_buff *skb)
1240 {
1241         unsigned long now = jiffies;
1242         unsigned long sched_next = now + (net_random() % p->proxy_delay);
1243
1244         if (tbl->proxy_queue.qlen > p->proxy_qlen) {
1245                 kfree_skb(skb);
1246                 return;
1247         }
1248
1249         NEIGH_CB(skb)->sched_next = sched_next;
1250         NEIGH_CB(skb)->flags |= LOCALLY_ENQUEUED;
1251
1252         spin_lock(&tbl->proxy_queue.lock);
1253         if (del_timer(&tbl->proxy_timer)) {
1254                 if (time_before(tbl->proxy_timer.expires, sched_next))
1255                         sched_next = tbl->proxy_timer.expires;
1256         }
1257         dst_release(skb->dst);
1258         skb->dst = NULL;
1259         dev_hold(skb->dev);
1260         __skb_queue_tail(&tbl->proxy_queue, skb);
1261         mod_timer(&tbl->proxy_timer, sched_next);
1262         spin_unlock(&tbl->proxy_queue.lock);
1263 }
1264
1265
1266 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
1267                                       struct neigh_table *tbl)
1268 {
1269         struct neigh_parms *p = kmalloc(sizeof(*p), GFP_KERNEL);
1270
1271         if (p) {
1272                 memcpy(p, &tbl->parms, sizeof(*p));
1273                 p->tbl            = tbl;
1274                 atomic_set(&p->refcnt, 1);
1275                 INIT_RCU_HEAD(&p->rcu_head);
1276                 p->reachable_time =
1277                                 neigh_rand_reach_time(p->base_reachable_time);
1278                 if (dev) {
1279                         if (dev->neigh_setup && dev->neigh_setup(dev, p)) {
1280                                 kfree(p);
1281                                 return NULL;
1282                         }
1283
1284                         dev_hold(dev);
1285                         p->dev = dev;
1286                 }
1287                 p->sysctl_table = NULL;
1288                 write_lock_bh(&tbl->lock);
1289                 p->next         = tbl->parms.next;
1290                 tbl->parms.next = p;
1291                 write_unlock_bh(&tbl->lock);
1292         }
1293         return p;
1294 }
1295
1296 static void neigh_rcu_free_parms(struct rcu_head *head)
1297 {
1298         struct neigh_parms *parms =
1299                 container_of(head, struct neigh_parms, rcu_head);
1300
1301         neigh_parms_put(parms);
1302 }
1303
1304 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
1305 {
1306         struct neigh_parms **p;
1307
1308         if (!parms || parms == &tbl->parms)
1309                 return;
1310         write_lock_bh(&tbl->lock);
1311         for (p = &tbl->parms.next; *p; p = &(*p)->next) {
1312                 if (*p == parms) {
1313                         *p = parms->next;
1314                         parms->dead = 1;
1315                         write_unlock_bh(&tbl->lock);
1316                         if (parms->dev)
1317                                 dev_put(parms->dev);
1318                         call_rcu(&parms->rcu_head, neigh_rcu_free_parms);
1319                         return;
1320                 }
1321         }
1322         write_unlock_bh(&tbl->lock);
1323         NEIGH_PRINTK1("neigh_parms_release: not found\n");
1324 }
1325
1326 void neigh_parms_destroy(struct neigh_parms *parms)
1327 {
1328         kfree(parms);
1329 }
1330
1331 void neigh_table_init_no_netlink(struct neigh_table *tbl)
1332 {
1333         unsigned long now = jiffies;
1334         unsigned long phsize;
1335
1336         atomic_set(&tbl->parms.refcnt, 1);
1337         INIT_RCU_HEAD(&tbl->parms.rcu_head);
1338         tbl->parms.reachable_time =
1339                           neigh_rand_reach_time(tbl->parms.base_reachable_time);
1340
1341         if (!tbl->kmem_cachep)
1342                 tbl->kmem_cachep =
1343                         kmem_cache_create(tbl->id, tbl->entry_size, 0,
1344                                           SLAB_HWCACHE_ALIGN|SLAB_PANIC,
1345                                           NULL, NULL);
1346         tbl->stats = alloc_percpu(struct neigh_statistics);
1347         if (!tbl->stats)
1348                 panic("cannot create neighbour cache statistics");
1349
1350 #ifdef CONFIG_PROC_FS
1351         tbl->pde = create_proc_entry(tbl->id, 0, proc_net_stat);
1352         if (!tbl->pde)
1353                 panic("cannot create neighbour proc dir entry");
1354         tbl->pde->proc_fops = &neigh_stat_seq_fops;
1355         tbl->pde->data = tbl;
1356 #endif
1357
1358         tbl->hash_mask = 1;
1359         tbl->hash_buckets = neigh_hash_alloc(tbl->hash_mask + 1);
1360
1361         phsize = (PNEIGH_HASHMASK + 1) * sizeof(struct pneigh_entry *);
1362         tbl->phash_buckets = kzalloc(phsize, GFP_KERNEL);
1363
1364         if (!tbl->hash_buckets || !tbl->phash_buckets)
1365                 panic("cannot allocate neighbour cache hashes");
1366
1367         get_random_bytes(&tbl->hash_rnd, sizeof(tbl->hash_rnd));
1368
1369         rwlock_init(&tbl->lock);
1370         init_timer(&tbl->gc_timer);
1371         tbl->gc_timer.data     = (unsigned long)tbl;
1372         tbl->gc_timer.function = neigh_periodic_timer;
1373         tbl->gc_timer.expires  = now + 1;
1374         add_timer(&tbl->gc_timer);
1375
1376         init_timer(&tbl->proxy_timer);
1377         tbl->proxy_timer.data     = (unsigned long)tbl;
1378         tbl->proxy_timer.function = neigh_proxy_process;
1379         skb_queue_head_init(&tbl->proxy_queue);
1380
1381         tbl->last_flush = now;
1382         tbl->last_rand  = now + tbl->parms.reachable_time * 20;
1383 }
1384
1385 void neigh_table_init(struct neigh_table *tbl)
1386 {
1387         struct neigh_table *tmp;
1388
1389         neigh_table_init_no_netlink(tbl);
1390         write_lock(&neigh_tbl_lock);
1391         for (tmp = neigh_tables; tmp; tmp = tmp->next) {
1392                 if (tmp->family == tbl->family)
1393                         break;
1394         }
1395         tbl->next       = neigh_tables;
1396         neigh_tables    = tbl;
1397         write_unlock(&neigh_tbl_lock);
1398
1399         if (unlikely(tmp)) {
1400                 printk(KERN_ERR "NEIGH: Registering multiple tables for "
1401                        "family %d\n", tbl->family);
1402                 dump_stack();
1403         }
1404 }
1405
1406 int neigh_table_clear(struct neigh_table *tbl)
1407 {
1408         struct neigh_table **tp;
1409
1410         /* It is not clean... Fix it to unload IPv6 module safely */
1411         del_timer_sync(&tbl->gc_timer);
1412         del_timer_sync(&tbl->proxy_timer);
1413         pneigh_queue_purge(&tbl->proxy_queue);
1414         neigh_ifdown(tbl, NULL);
1415         if (atomic_read(&tbl->entries))
1416                 printk(KERN_CRIT "neighbour leakage\n");
1417         write_lock(&neigh_tbl_lock);
1418         for (tp = &neigh_tables; *tp; tp = &(*tp)->next) {
1419                 if (*tp == tbl) {
1420                         *tp = tbl->next;
1421                         break;
1422                 }
1423         }
1424         write_unlock(&neigh_tbl_lock);
1425
1426         neigh_hash_free(tbl->hash_buckets, tbl->hash_mask + 1);
1427         tbl->hash_buckets = NULL;
1428
1429         kfree(tbl->phash_buckets);
1430         tbl->phash_buckets = NULL;
1431
1432         free_percpu(tbl->stats);
1433         tbl->stats = NULL;
1434
1435         return 0;
1436 }
1437
1438 int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
1439 {
1440         struct ndmsg *ndm;
1441         struct nlattr *dst_attr;
1442         struct neigh_table *tbl;
1443         struct net_device *dev = NULL;
1444         int err = -EINVAL;
1445
1446         if (nlmsg_len(nlh) < sizeof(*ndm))
1447                 goto out;
1448
1449         dst_attr = nlmsg_find_attr(nlh, sizeof(*ndm), NDA_DST);
1450         if (dst_attr == NULL)
1451                 goto out;
1452
1453         ndm = nlmsg_data(nlh);
1454         if (ndm->ndm_ifindex) {
1455                 dev = dev_get_by_index(ndm->ndm_ifindex);
1456                 if (dev == NULL) {
1457                         err = -ENODEV;
1458                         goto out;
1459                 }
1460         }
1461
1462         read_lock(&neigh_tbl_lock);
1463         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1464                 struct neighbour *neigh;
1465
1466                 if (tbl->family != ndm->ndm_family)
1467                         continue;
1468                 read_unlock(&neigh_tbl_lock);
1469
1470                 if (nla_len(dst_attr) < tbl->key_len)
1471                         goto out_dev_put;
1472
1473                 if (ndm->ndm_flags & NTF_PROXY) {
1474                         err = pneigh_delete(tbl, nla_data(dst_attr), dev);
1475                         goto out_dev_put;
1476                 }
1477
1478                 if (dev == NULL)
1479                         goto out_dev_put;
1480
1481                 neigh = neigh_lookup(tbl, nla_data(dst_attr), dev);
1482                 if (neigh == NULL) {
1483                         err = -ENOENT;
1484                         goto out_dev_put;
1485                 }
1486
1487                 err = neigh_update(neigh, NULL, NUD_FAILED,
1488                                    NEIGH_UPDATE_F_OVERRIDE |
1489                                    NEIGH_UPDATE_F_ADMIN);
1490                 neigh_release(neigh);
1491                 goto out_dev_put;
1492         }
1493         read_unlock(&neigh_tbl_lock);
1494         err = -EAFNOSUPPORT;
1495
1496 out_dev_put:
1497         if (dev)
1498                 dev_put(dev);
1499 out:
1500         return err;
1501 }
1502
1503 int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
1504 {
1505         struct ndmsg *ndm;
1506         struct nlattr *tb[NDA_MAX+1];
1507         struct neigh_table *tbl;
1508         struct net_device *dev = NULL;
1509         int err;
1510
1511         err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
1512         if (err < 0)
1513                 goto out;
1514
1515         err = -EINVAL;
1516         if (tb[NDA_DST] == NULL)
1517                 goto out;
1518
1519         ndm = nlmsg_data(nlh);
1520         if (ndm->ndm_ifindex) {
1521                 dev = dev_get_by_index(ndm->ndm_ifindex);
1522                 if (dev == NULL) {
1523                         err = -ENODEV;
1524                         goto out;
1525                 }
1526
1527                 if (tb[NDA_LLADDR] && nla_len(tb[NDA_LLADDR]) < dev->addr_len)
1528                         goto out_dev_put;
1529         }
1530
1531         read_lock(&neigh_tbl_lock);
1532         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1533                 int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE;
1534                 struct neighbour *neigh;
1535                 void *dst, *lladdr;
1536
1537                 if (tbl->family != ndm->ndm_family)
1538                         continue;
1539                 read_unlock(&neigh_tbl_lock);
1540
1541                 if (nla_len(tb[NDA_DST]) < tbl->key_len)
1542                         goto out_dev_put;
1543                 dst = nla_data(tb[NDA_DST]);
1544                 lladdr = tb[NDA_LLADDR] ? nla_data(tb[NDA_LLADDR]) : NULL;
1545
1546                 if (ndm->ndm_flags & NTF_PROXY) {
1547                         err = 0;
1548                         if (pneigh_lookup(tbl, dst, dev, 1) == NULL)
1549                                 err = -ENOBUFS;
1550                         goto out_dev_put;
1551                 }
1552
1553                 if (dev == NULL)
1554                         goto out_dev_put;
1555
1556                 neigh = neigh_lookup(tbl, dst, dev);
1557                 if (neigh == NULL) {
1558                         if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
1559                                 err = -ENOENT;
1560                                 goto out_dev_put;
1561                         }
1562
1563                         neigh = __neigh_lookup_errno(tbl, dst, dev);
1564                         if (IS_ERR(neigh)) {
1565                                 err = PTR_ERR(neigh);
1566                                 goto out_dev_put;
1567                         }
1568                 } else {
1569                         if (nlh->nlmsg_flags & NLM_F_EXCL) {
1570                                 err = -EEXIST;
1571                                 neigh_release(neigh);
1572                                 goto out_dev_put;
1573                         }
1574
1575                         if (!(nlh->nlmsg_flags & NLM_F_REPLACE))
1576                                 flags &= ~NEIGH_UPDATE_F_OVERRIDE;
1577                 }
1578
1579                 err = neigh_update(neigh, lladdr, ndm->ndm_state, flags);
1580                 neigh_release(neigh);
1581                 goto out_dev_put;
1582         }
1583
1584         read_unlock(&neigh_tbl_lock);
1585         err = -EAFNOSUPPORT;
1586
1587 out_dev_put:
1588         if (dev)
1589                 dev_put(dev);
1590 out:
1591         return err;
1592 }
1593
1594 static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms)
1595 {
1596         struct nlattr *nest;
1597
1598         nest = nla_nest_start(skb, NDTA_PARMS);
1599         if (nest == NULL)
1600                 return -ENOBUFS;
1601
1602         if (parms->dev)
1603                 NLA_PUT_U32(skb, NDTPA_IFINDEX, parms->dev->ifindex);
1604
1605         NLA_PUT_U32(skb, NDTPA_REFCNT, atomic_read(&parms->refcnt));
1606         NLA_PUT_U32(skb, NDTPA_QUEUE_LEN, parms->queue_len);
1607         NLA_PUT_U32(skb, NDTPA_PROXY_QLEN, parms->proxy_qlen);
1608         NLA_PUT_U32(skb, NDTPA_APP_PROBES, parms->app_probes);
1609         NLA_PUT_U32(skb, NDTPA_UCAST_PROBES, parms->ucast_probes);
1610         NLA_PUT_U32(skb, NDTPA_MCAST_PROBES, parms->mcast_probes);
1611         NLA_PUT_MSECS(skb, NDTPA_REACHABLE_TIME, parms->reachable_time);
1612         NLA_PUT_MSECS(skb, NDTPA_BASE_REACHABLE_TIME,
1613                       parms->base_reachable_time);
1614         NLA_PUT_MSECS(skb, NDTPA_GC_STALETIME, parms->gc_staletime);
1615         NLA_PUT_MSECS(skb, NDTPA_DELAY_PROBE_TIME, parms->delay_probe_time);
1616         NLA_PUT_MSECS(skb, NDTPA_RETRANS_TIME, parms->retrans_time);
1617         NLA_PUT_MSECS(skb, NDTPA_ANYCAST_DELAY, parms->anycast_delay);
1618         NLA_PUT_MSECS(skb, NDTPA_PROXY_DELAY, parms->proxy_delay);
1619         NLA_PUT_MSECS(skb, NDTPA_LOCKTIME, parms->locktime);
1620
1621         return nla_nest_end(skb, nest);
1622
1623 nla_put_failure:
1624         return nla_nest_cancel(skb, nest);
1625 }
1626
1627 static int neightbl_fill_info(struct sk_buff *skb, struct neigh_table *tbl,
1628                               u32 pid, u32 seq, int type, int flags)
1629 {
1630         struct nlmsghdr *nlh;
1631         struct ndtmsg *ndtmsg;
1632
1633         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
1634         if (nlh == NULL)
1635                 return -ENOBUFS;
1636
1637         ndtmsg = nlmsg_data(nlh);
1638
1639         read_lock_bh(&tbl->lock);
1640         ndtmsg->ndtm_family = tbl->family;
1641         ndtmsg->ndtm_pad1   = 0;
1642         ndtmsg->ndtm_pad2   = 0;
1643
1644         NLA_PUT_STRING(skb, NDTA_NAME, tbl->id);
1645         NLA_PUT_MSECS(skb, NDTA_GC_INTERVAL, tbl->gc_interval);
1646         NLA_PUT_U32(skb, NDTA_THRESH1, tbl->gc_thresh1);
1647         NLA_PUT_U32(skb, NDTA_THRESH2, tbl->gc_thresh2);
1648         NLA_PUT_U32(skb, NDTA_THRESH3, tbl->gc_thresh3);
1649
1650         {
1651                 unsigned long now = jiffies;
1652                 unsigned int flush_delta = now - tbl->last_flush;
1653                 unsigned int rand_delta = now - tbl->last_rand;
1654
1655                 struct ndt_config ndc = {
1656                         .ndtc_key_len           = tbl->key_len,
1657                         .ndtc_entry_size        = tbl->entry_size,
1658                         .ndtc_entries           = atomic_read(&tbl->entries),
1659                         .ndtc_last_flush        = jiffies_to_msecs(flush_delta),
1660                         .ndtc_last_rand         = jiffies_to_msecs(rand_delta),
1661                         .ndtc_hash_rnd          = tbl->hash_rnd,
1662                         .ndtc_hash_mask         = tbl->hash_mask,
1663                         .ndtc_hash_chain_gc     = tbl->hash_chain_gc,
1664                         .ndtc_proxy_qlen        = tbl->proxy_queue.qlen,
1665                 };
1666
1667                 NLA_PUT(skb, NDTA_CONFIG, sizeof(ndc), &ndc);
1668         }
1669
1670         {
1671                 int cpu;
1672                 struct ndt_stats ndst;
1673
1674                 memset(&ndst, 0, sizeof(ndst));
1675
1676                 for_each_possible_cpu(cpu) {
1677                         struct neigh_statistics *st;
1678
1679                         st = per_cpu_ptr(tbl->stats, cpu);
1680                         ndst.ndts_allocs                += st->allocs;
1681                         ndst.ndts_destroys              += st->destroys;
1682                         ndst.ndts_hash_grows            += st->hash_grows;
1683                         ndst.ndts_res_failed            += st->res_failed;
1684                         ndst.ndts_lookups               += st->lookups;
1685                         ndst.ndts_hits                  += st->hits;
1686                         ndst.ndts_rcv_probes_mcast      += st->rcv_probes_mcast;
1687                         ndst.ndts_rcv_probes_ucast      += st->rcv_probes_ucast;
1688                         ndst.ndts_periodic_gc_runs      += st->periodic_gc_runs;
1689                         ndst.ndts_forced_gc_runs        += st->forced_gc_runs;
1690                 }
1691
1692                 NLA_PUT(skb, NDTA_STATS, sizeof(ndst), &ndst);
1693         }
1694
1695         BUG_ON(tbl->parms.dev);
1696         if (neightbl_fill_parms(skb, &tbl->parms) < 0)
1697                 goto nla_put_failure;
1698
1699         read_unlock_bh(&tbl->lock);
1700         return nlmsg_end(skb, nlh);
1701
1702 nla_put_failure:
1703         read_unlock_bh(&tbl->lock);
1704         return nlmsg_cancel(skb, nlh);
1705 }
1706
1707 static int neightbl_fill_param_info(struct sk_buff *skb,
1708                                     struct neigh_table *tbl,
1709                                     struct neigh_parms *parms,
1710                                     u32 pid, u32 seq, int type,
1711                                     unsigned int flags)
1712 {
1713         struct ndtmsg *ndtmsg;
1714         struct nlmsghdr *nlh;
1715
1716         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
1717         if (nlh == NULL)
1718                 return -ENOBUFS;
1719
1720         ndtmsg = nlmsg_data(nlh);
1721
1722         read_lock_bh(&tbl->lock);
1723         ndtmsg->ndtm_family = tbl->family;
1724         ndtmsg->ndtm_pad1   = 0;
1725         ndtmsg->ndtm_pad2   = 0;
1726
1727         if (nla_put_string(skb, NDTA_NAME, tbl->id) < 0 ||
1728             neightbl_fill_parms(skb, parms) < 0)
1729                 goto errout;
1730
1731         read_unlock_bh(&tbl->lock);
1732         return nlmsg_end(skb, nlh);
1733 errout:
1734         read_unlock_bh(&tbl->lock);
1735         return nlmsg_cancel(skb, nlh);
1736 }
1737
1738 static inline struct neigh_parms *lookup_neigh_params(struct neigh_table *tbl,
1739                                                       int ifindex)
1740 {
1741         struct neigh_parms *p;
1742
1743         for (p = &tbl->parms; p; p = p->next)
1744                 if ((p->dev && p->dev->ifindex == ifindex) ||
1745                     (!p->dev && !ifindex))
1746                         return p;
1747
1748         return NULL;
1749 }
1750
1751 static struct nla_policy nl_neightbl_policy[NDTA_MAX+1] __read_mostly = {
1752         [NDTA_NAME]             = { .type = NLA_STRING },
1753         [NDTA_THRESH1]          = { .type = NLA_U32 },
1754         [NDTA_THRESH2]          = { .type = NLA_U32 },
1755         [NDTA_THRESH3]          = { .type = NLA_U32 },
1756         [NDTA_GC_INTERVAL]      = { .type = NLA_U64 },
1757         [NDTA_PARMS]            = { .type = NLA_NESTED },
1758 };
1759
1760 static struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] __read_mostly = {
1761         [NDTPA_IFINDEX]                 = { .type = NLA_U32 },
1762         [NDTPA_QUEUE_LEN]               = { .type = NLA_U32 },
1763         [NDTPA_PROXY_QLEN]              = { .type = NLA_U32 },
1764         [NDTPA_APP_PROBES]              = { .type = NLA_U32 },
1765         [NDTPA_UCAST_PROBES]            = { .type = NLA_U32 },
1766         [NDTPA_MCAST_PROBES]            = { .type = NLA_U32 },
1767         [NDTPA_BASE_REACHABLE_TIME]     = { .type = NLA_U64 },
1768         [NDTPA_GC_STALETIME]            = { .type = NLA_U64 },
1769         [NDTPA_DELAY_PROBE_TIME]        = { .type = NLA_U64 },
1770         [NDTPA_RETRANS_TIME]            = { .type = NLA_U64 },
1771         [NDTPA_ANYCAST_DELAY]           = { .type = NLA_U64 },
1772         [NDTPA_PROXY_DELAY]             = { .type = NLA_U64 },
1773         [NDTPA_LOCKTIME]                = { .type = NLA_U64 },
1774 };
1775
1776 int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
1777 {
1778         struct neigh_table *tbl;
1779         struct ndtmsg *ndtmsg;
1780         struct nlattr *tb[NDTA_MAX+1];
1781         int err;
1782
1783         err = nlmsg_parse(nlh, sizeof(*ndtmsg), tb, NDTA_MAX,
1784                           nl_neightbl_policy);
1785         if (err < 0)
1786                 goto errout;
1787
1788         if (tb[NDTA_NAME] == NULL) {
1789                 err = -EINVAL;
1790                 goto errout;
1791         }
1792
1793         ndtmsg = nlmsg_data(nlh);
1794         read_lock(&neigh_tbl_lock);
1795         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1796                 if (ndtmsg->ndtm_family && tbl->family != ndtmsg->ndtm_family)
1797                         continue;
1798
1799                 if (nla_strcmp(tb[NDTA_NAME], tbl->id) == 0)
1800                         break;
1801         }
1802
1803         if (tbl == NULL) {
1804                 err = -ENOENT;
1805                 goto errout_locked;
1806         }
1807
1808         /*
1809          * We acquire tbl->lock to be nice to the periodic timers and
1810          * make sure they always see a consistent set of values.
1811          */
1812         write_lock_bh(&tbl->lock);
1813
1814         if (tb[NDTA_PARMS]) {
1815                 struct nlattr *tbp[NDTPA_MAX+1];
1816                 struct neigh_parms *p;
1817                 int i, ifindex = 0;
1818
1819                 err = nla_parse_nested(tbp, NDTPA_MAX, tb[NDTA_PARMS],
1820                                        nl_ntbl_parm_policy);
1821                 if (err < 0)
1822                         goto errout_tbl_lock;
1823
1824                 if (tbp[NDTPA_IFINDEX])
1825                         ifindex = nla_get_u32(tbp[NDTPA_IFINDEX]);
1826
1827                 p = lookup_neigh_params(tbl, ifindex);
1828                 if (p == NULL) {
1829                         err = -ENOENT;
1830                         goto errout_tbl_lock;
1831                 }
1832
1833                 for (i = 1; i <= NDTPA_MAX; i++) {
1834                         if (tbp[i] == NULL)
1835                                 continue;
1836
1837                         switch (i) {
1838                         case NDTPA_QUEUE_LEN:
1839                                 p->queue_len = nla_get_u32(tbp[i]);
1840                                 break;
1841                         case NDTPA_PROXY_QLEN:
1842                                 p->proxy_qlen = nla_get_u32(tbp[i]);
1843                                 break;
1844                         case NDTPA_APP_PROBES:
1845                                 p->app_probes = nla_get_u32(tbp[i]);
1846                                 break;
1847                         case NDTPA_UCAST_PROBES:
1848                                 p->ucast_probes = nla_get_u32(tbp[i]);
1849                                 break;
1850                         case NDTPA_MCAST_PROBES:
1851                                 p->mcast_probes = nla_get_u32(tbp[i]);
1852                                 break;
1853                         case NDTPA_BASE_REACHABLE_TIME:
1854                                 p->base_reachable_time = nla_get_msecs(tbp[i]);
1855                                 break;
1856                         case NDTPA_GC_STALETIME:
1857                                 p->gc_staletime = nla_get_msecs(tbp[i]);
1858                                 break;
1859                         case NDTPA_DELAY_PROBE_TIME:
1860                                 p->delay_probe_time = nla_get_msecs(tbp[i]);
1861                                 break;
1862                         case NDTPA_RETRANS_TIME:
1863                                 p->retrans_time = nla_get_msecs(tbp[i]);
1864                                 break;
1865                         case NDTPA_ANYCAST_DELAY:
1866                                 p->anycast_delay = nla_get_msecs(tbp[i]);
1867                                 break;
1868                         case NDTPA_PROXY_DELAY:
1869                                 p->proxy_delay = nla_get_msecs(tbp[i]);
1870                                 break;
1871                         case NDTPA_LOCKTIME:
1872                                 p->locktime = nla_get_msecs(tbp[i]);
1873                                 break;
1874                         }
1875                 }
1876         }
1877
1878         if (tb[NDTA_THRESH1])
1879                 tbl->gc_thresh1 = nla_get_u32(tb[NDTA_THRESH1]);
1880
1881         if (tb[NDTA_THRESH2])
1882                 tbl->gc_thresh2 = nla_get_u32(tb[NDTA_THRESH2]);
1883
1884         if (tb[NDTA_THRESH3])
1885                 tbl->gc_thresh3 = nla_get_u32(tb[NDTA_THRESH3]);
1886
1887         if (tb[NDTA_GC_INTERVAL])
1888                 tbl->gc_interval = nla_get_msecs(tb[NDTA_GC_INTERVAL]);
1889
1890         err = 0;
1891
1892 errout_tbl_lock:
1893         write_unlock_bh(&tbl->lock);
1894 errout_locked:
1895         read_unlock(&neigh_tbl_lock);
1896 errout:
1897         return err;
1898 }
1899
1900 int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
1901 {
1902         int family, tidx, nidx = 0;
1903         int tbl_skip = cb->args[0];
1904         int neigh_skip = cb->args[1];
1905         struct neigh_table *tbl;
1906
1907         family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;
1908
1909         read_lock(&neigh_tbl_lock);
1910         for (tbl = neigh_tables, tidx = 0; tbl; tbl = tbl->next, tidx++) {
1911                 struct neigh_parms *p;
1912
1913                 if (tidx < tbl_skip || (family && tbl->family != family))
1914                         continue;
1915
1916                 if (neightbl_fill_info(skb, tbl, NETLINK_CB(cb->skb).pid,
1917                                        cb->nlh->nlmsg_seq, RTM_NEWNEIGHTBL,
1918                                        NLM_F_MULTI) <= 0)
1919                         break;
1920
1921                 for (nidx = 0, p = tbl->parms.next; p; p = p->next, nidx++) {
1922                         if (nidx < neigh_skip)
1923                                 continue;
1924
1925                         if (neightbl_fill_param_info(skb, tbl, p,
1926                                                      NETLINK_CB(cb->skb).pid,
1927                                                      cb->nlh->nlmsg_seq,
1928                                                      RTM_NEWNEIGHTBL,
1929                                                      NLM_F_MULTI) <= 0)
1930                                 goto out;
1931                 }
1932
1933                 neigh_skip = 0;
1934         }
1935 out:
1936         read_unlock(&neigh_tbl_lock);
1937         cb->args[0] = tidx;
1938         cb->args[1] = nidx;
1939
1940         return skb->len;
1941 }
1942
1943 static int neigh_fill_info(struct sk_buff *skb, struct neighbour *neigh,
1944                            u32 pid, u32 seq, int type, unsigned int flags)
1945 {
1946         unsigned long now = jiffies;
1947         struct nda_cacheinfo ci;
1948         struct nlmsghdr *nlh;
1949         struct ndmsg *ndm;
1950
1951         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
1952         if (nlh == NULL)
1953                 return -ENOBUFS;
1954
1955         ndm = nlmsg_data(nlh);
1956         ndm->ndm_family  = neigh->ops->family;
1957         ndm->ndm_pad1    = 0;
1958         ndm->ndm_pad2    = 0;
1959         ndm->ndm_flags   = neigh->flags;
1960         ndm->ndm_type    = neigh->type;
1961         ndm->ndm_ifindex = neigh->dev->ifindex;
1962
1963         NLA_PUT(skb, NDA_DST, neigh->tbl->key_len, neigh->primary_key);
1964
1965         read_lock_bh(&neigh->lock);
1966         ndm->ndm_state   = neigh->nud_state;
1967         if ((neigh->nud_state & NUD_VALID) &&
1968             nla_put(skb, NDA_LLADDR, neigh->dev->addr_len, neigh->ha) < 0) {
1969                 read_unlock_bh(&neigh->lock);
1970                 goto nla_put_failure;
1971         }
1972
1973         ci.ndm_used      = now - neigh->used;
1974         ci.ndm_confirmed = now - neigh->confirmed;
1975         ci.ndm_updated   = now - neigh->updated;
1976         ci.ndm_refcnt    = atomic_read(&neigh->refcnt) - 1;
1977         read_unlock_bh(&neigh->lock);
1978
1979         NLA_PUT_U32(skb, NDA_PROBES, atomic_read(&neigh->probes));
1980         NLA_PUT(skb, NDA_CACHEINFO, sizeof(ci), &ci);
1981
1982         return nlmsg_end(skb, nlh);
1983
1984 nla_put_failure:
1985         return nlmsg_cancel(skb, nlh);
1986 }
1987
1988
1989 static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
1990                             struct netlink_callback *cb)
1991 {
1992         struct neighbour *n;
1993         int rc, h, s_h = cb->args[1];
1994         int idx, s_idx = idx = cb->args[2];
1995
1996         for (h = 0; h <= tbl->hash_mask; h++) {
1997                 if (h < s_h)
1998                         continue;
1999                 if (h > s_h)
2000                         s_idx = 0;
2001                 read_lock_bh(&tbl->lock);
2002                 for (n = tbl->hash_buckets[h], idx = 0; n; n = n->next, idx++) {
2003                         if (idx < s_idx)
2004                                 continue;
2005                         if (neigh_fill_info(skb, n, NETLINK_CB(cb->skb).pid,
2006                                             cb->nlh->nlmsg_seq,
2007                                             RTM_NEWNEIGH,
2008                                             NLM_F_MULTI) <= 0) {
2009                                 read_unlock_bh(&tbl->lock);
2010                                 rc = -1;
2011                                 goto out;
2012                         }
2013                 }
2014                 read_unlock_bh(&tbl->lock);
2015         }
2016         rc = skb->len;
2017 out:
2018         cb->args[1] = h;
2019         cb->args[2] = idx;
2020         return rc;
2021 }
2022
2023 int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2024 {
2025         struct neigh_table *tbl;
2026         int t, family, s_t;
2027
2028         read_lock(&neigh_tbl_lock);
2029         family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;
2030         s_t = cb->args[0];
2031
2032         for (tbl = neigh_tables, t = 0; tbl; tbl = tbl->next, t++) {
2033                 if (t < s_t || (family && tbl->family != family))
2034                         continue;
2035                 if (t > s_t)
2036                         memset(&cb->args[1], 0, sizeof(cb->args) -
2037                                                 sizeof(cb->args[0]));
2038                 if (neigh_dump_table(tbl, skb, cb) < 0)
2039                         break;
2040         }
2041         read_unlock(&neigh_tbl_lock);
2042
2043         cb->args[0] = t;
2044         return skb->len;
2045 }
2046
2047 void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie)
2048 {
2049         int chain;
2050
2051         read_lock_bh(&tbl->lock);
2052         for (chain = 0; chain <= tbl->hash_mask; chain++) {
2053                 struct neighbour *n;
2054
2055                 for (n = tbl->hash_buckets[chain]; n; n = n->next)
2056                         cb(n, cookie);
2057         }
2058         read_unlock_bh(&tbl->lock);
2059 }
2060 EXPORT_SYMBOL(neigh_for_each);
2061
2062 /* The tbl->lock must be held as a writer and BH disabled. */
2063 void __neigh_for_each_release(struct neigh_table *tbl,
2064                               int (*cb)(struct neighbour *))
2065 {
2066         int chain;
2067
2068         for (chain = 0; chain <= tbl->hash_mask; chain++) {
2069                 struct neighbour *n, **np;
2070
2071                 np = &tbl->hash_buckets[chain];
2072                 while ((n = *np) != NULL) {
2073                         int release;
2074
2075                         write_lock(&n->lock);
2076                         release = cb(n);
2077                         if (release) {
2078                                 *np = n->next;
2079                                 n->dead = 1;
2080                         } else
2081                                 np = &n->next;
2082                         write_unlock(&n->lock);
2083                         if (release)
2084                                 neigh_release(n);
2085                 }
2086         }
2087 }
2088 EXPORT_SYMBOL(__neigh_for_each_release);
2089
2090 #ifdef CONFIG_PROC_FS
2091
2092 static struct neighbour *neigh_get_first(struct seq_file *seq)
2093 {
2094         struct neigh_seq_state *state = seq->private;
2095         struct neigh_table *tbl = state->tbl;
2096         struct neighbour *n = NULL;
2097         int bucket = state->bucket;
2098
2099         state->flags &= ~NEIGH_SEQ_IS_PNEIGH;
2100         for (bucket = 0; bucket <= tbl->hash_mask; bucket++) {
2101                 n = tbl->hash_buckets[bucket];
2102
2103                 while (n) {
2104                         if (state->neigh_sub_iter) {
2105                                 loff_t fakep = 0;
2106                                 void *v;
2107
2108                                 v = state->neigh_sub_iter(state, n, &fakep);
2109                                 if (!v)
2110                                         goto next;
2111                         }
2112                         if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
2113                                 break;
2114                         if (n->nud_state & ~NUD_NOARP)
2115                                 break;
2116                 next:
2117                         n = n->next;
2118                 }
2119
2120                 if (n)
2121                         break;
2122         }
2123         state->bucket = bucket;
2124
2125         return n;
2126 }
2127
2128 static struct neighbour *neigh_get_next(struct seq_file *seq,
2129                                         struct neighbour *n,
2130                                         loff_t *pos)
2131 {
2132         struct neigh_seq_state *state = seq->private;
2133         struct neigh_table *tbl = state->tbl;
2134
2135         if (state->neigh_sub_iter) {
2136                 void *v = state->neigh_sub_iter(state, n, pos);
2137                 if (v)
2138                         return n;
2139         }
2140         n = n->next;
2141
2142         while (1) {
2143                 while (n) {
2144                         if (state->neigh_sub_iter) {
2145                                 void *v = state->neigh_sub_iter(state, n, pos);
2146                                 if (v)
2147                                         return n;
2148                                 goto next;
2149                         }
2150                         if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
2151                                 break;
2152
2153                         if (n->nud_state & ~NUD_NOARP)
2154                                 break;
2155                 next:
2156                         n = n->next;
2157                 }
2158
2159                 if (n)
2160                         break;
2161
2162                 if (++state->bucket > tbl->hash_mask)
2163                         break;
2164
2165                 n = tbl->hash_buckets[state->bucket];
2166         }
2167
2168         if (n && pos)
2169                 --(*pos);
2170         return n;
2171 }
2172
2173 static struct neighbour *neigh_get_idx(struct seq_file *seq, loff_t *pos)
2174 {
2175         struct neighbour *n = neigh_get_first(seq);
2176
2177         if (n) {
2178                 while (*pos) {
2179                         n = neigh_get_next(seq, n, pos);
2180                         if (!n)
2181                                 break;
2182                 }
2183         }
2184         return *pos ? NULL : n;
2185 }
2186
2187 static struct pneigh_entry *pneigh_get_first(struct seq_file *seq)
2188 {
2189         struct neigh_seq_state *state = seq->private;
2190         struct neigh_table *tbl = state->tbl;
2191         struct pneigh_entry *pn = NULL;
2192         int bucket = state->bucket;
2193
2194         state->flags |= NEIGH_SEQ_IS_PNEIGH;
2195         for (bucket = 0; bucket <= PNEIGH_HASHMASK; bucket++) {
2196                 pn = tbl->phash_buckets[bucket];
2197                 if (pn)
2198                         break;
2199         }
2200         state->bucket = bucket;
2201
2202         return pn;
2203 }
2204
2205 static struct pneigh_entry *pneigh_get_next(struct seq_file *seq,
2206                                             struct pneigh_entry *pn,
2207                                             loff_t *pos)
2208 {
2209         struct neigh_seq_state *state = seq->private;
2210         struct neigh_table *tbl = state->tbl;
2211
2212         pn = pn->next;
2213         while (!pn) {
2214                 if (++state->bucket > PNEIGH_HASHMASK)
2215                         break;
2216                 pn = tbl->phash_buckets[state->bucket];
2217                 if (pn)
2218                         break;
2219         }
2220
2221         if (pn && pos)
2222                 --(*pos);
2223
2224         return pn;
2225 }
2226
2227 static struct pneigh_entry *pneigh_get_idx(struct seq_file *seq, loff_t *pos)
2228 {
2229         struct pneigh_entry *pn = pneigh_get_first(seq);
2230
2231         if (pn) {
2232                 while (*pos) {
2233                         pn = pneigh_get_next(seq, pn, pos);
2234                         if (!pn)
2235                                 break;
2236                 }
2237         }
2238         return *pos ? NULL : pn;
2239 }
2240
2241 static void *neigh_get_idx_any(struct seq_file *seq, loff_t *pos)
2242 {
2243         struct neigh_seq_state *state = seq->private;
2244         void *rc;
2245
2246         rc = neigh_get_idx(seq, pos);
2247         if (!rc && !(state->flags & NEIGH_SEQ_NEIGH_ONLY))
2248                 rc = pneigh_get_idx(seq, pos);
2249
2250         return rc;
2251 }
2252
2253 void *neigh_seq_start(struct seq_file *seq, loff_t *pos, struct neigh_table *tbl, unsigned int neigh_seq_flags)
2254 {
2255         struct neigh_seq_state *state = seq->private;
2256         loff_t pos_minus_one;
2257
2258         state->tbl = tbl;
2259         state->bucket = 0;
2260         state->flags = (neigh_seq_flags & ~NEIGH_SEQ_IS_PNEIGH);
2261
2262         read_lock_bh(&tbl->lock);
2263
2264         pos_minus_one = *pos - 1;
2265         return *pos ? neigh_get_idx_any(seq, &pos_minus_one) : SEQ_START_TOKEN;
2266 }
2267 EXPORT_SYMBOL(neigh_seq_start);
2268
2269 void *neigh_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2270 {
2271         struct neigh_seq_state *state;
2272         void *rc;
2273
2274         if (v == SEQ_START_TOKEN) {
2275                 rc = neigh_get_idx(seq, pos);
2276                 goto out;
2277         }
2278
2279         state = seq->private;
2280         if (!(state->flags & NEIGH_SEQ_IS_PNEIGH)) {
2281                 rc = neigh_get_next(seq, v, NULL);
2282                 if (rc)
2283                         goto out;
2284                 if (!(state->flags & NEIGH_SEQ_NEIGH_ONLY))
2285                         rc = pneigh_get_first(seq);
2286         } else {
2287                 BUG_ON(state->flags & NEIGH_SEQ_NEIGH_ONLY);
2288                 rc = pneigh_get_next(seq, v, NULL);
2289         }
2290 out:
2291         ++(*pos);
2292         return rc;
2293 }
2294 EXPORT_SYMBOL(neigh_seq_next);
2295
2296 void neigh_seq_stop(struct seq_file *seq, void *v)
2297 {
2298         struct neigh_seq_state *state = seq->private;
2299         struct neigh_table *tbl = state->tbl;
2300
2301         read_unlock_bh(&tbl->lock);
2302 }
2303 EXPORT_SYMBOL(neigh_seq_stop);
2304
2305 /* statistics via seq_file */
2306
2307 static void *neigh_stat_seq_start(struct seq_file *seq, loff_t *pos)
2308 {
2309         struct proc_dir_entry *pde = seq->private;
2310         struct neigh_table *tbl = pde->data;
2311         int cpu;
2312
2313         if (*pos == 0)
2314                 return SEQ_START_TOKEN;
2315
2316         for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
2317                 if (!cpu_possible(cpu))
2318                         continue;
2319                 *pos = cpu+1;
2320                 return per_cpu_ptr(tbl->stats, cpu);
2321         }
2322         return NULL;
2323 }
2324
2325 static void *neigh_stat_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2326 {
2327         struct proc_dir_entry *pde = seq->private;
2328         struct neigh_table *tbl = pde->data;
2329         int cpu;
2330
2331         for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
2332                 if (!cpu_possible(cpu))
2333                         continue;
2334                 *pos = cpu+1;
2335                 return per_cpu_ptr(tbl->stats, cpu);
2336         }
2337         return NULL;
2338 }
2339
2340 static void neigh_stat_seq_stop(struct seq_file *seq, void *v)
2341 {
2342
2343 }
2344
2345 static int neigh_stat_seq_show(struct seq_file *seq, void *v)
2346 {
2347         struct proc_dir_entry *pde = seq->private;
2348         struct neigh_table *tbl = pde->data;
2349         struct neigh_statistics *st = v;
2350
2351         if (v == SEQ_START_TOKEN) {
2352                 seq_printf(seq, "entries  allocs destroys hash_grows  lookups hits  res_failed  rcv_probes_mcast rcv_probes_ucast  periodic_gc_runs forced_gc_runs\n");
2353                 return 0;
2354         }
2355
2356         seq_printf(seq, "%08x  %08lx %08lx %08lx  %08lx %08lx  %08lx  "
2357                         "%08lx %08lx  %08lx %08lx\n",
2358                    atomic_read(&tbl->entries),
2359
2360                    st->allocs,
2361                    st->destroys,
2362                    st->hash_grows,
2363
2364                    st->lookups,
2365                    st->hits,
2366
2367                    st->res_failed,
2368
2369                    st->rcv_probes_mcast,
2370                    st->rcv_probes_ucast,
2371
2372                    st->periodic_gc_runs,
2373                    st->forced_gc_runs
2374                    );
2375
2376         return 0;
2377 }
2378
2379 static struct seq_operations neigh_stat_seq_ops = {
2380         .start  = neigh_stat_seq_start,
2381         .next   = neigh_stat_seq_next,
2382         .stop   = neigh_stat_seq_stop,
2383         .show   = neigh_stat_seq_show,
2384 };
2385
2386 static int neigh_stat_seq_open(struct inode *inode, struct file *file)
2387 {
2388         int ret = seq_open(file, &neigh_stat_seq_ops);
2389
2390         if (!ret) {
2391                 struct seq_file *sf = file->private_data;
2392                 sf->private = PDE(inode);
2393         }
2394         return ret;
2395 };
2396
2397 static struct file_operations neigh_stat_seq_fops = {
2398         .owner   = THIS_MODULE,
2399         .open    = neigh_stat_seq_open,
2400         .read    = seq_read,
2401         .llseek  = seq_lseek,
2402         .release = seq_release,
2403 };
2404
2405 #endif /* CONFIG_PROC_FS */
2406
2407 #ifdef CONFIG_ARPD
2408 static void __neigh_notify(struct neighbour *n, int type, int flags)
2409 {
2410         struct sk_buff *skb;
2411         int err = -ENOBUFS;
2412
2413         skb = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
2414         if (skb == NULL)
2415                 goto errout;
2416
2417         err = neigh_fill_info(skb, n, 0, 0, type, flags);
2418         if (err < 0) {
2419                 kfree_skb(skb);
2420                 goto errout;
2421         }
2422
2423         err = rtnl_notify(skb, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
2424 errout:
2425         if (err < 0)
2426                 rtnl_set_sk_err(RTNLGRP_NEIGH, err);
2427 }
2428
2429 void neigh_app_ns(struct neighbour *n)
2430 {
2431         __neigh_notify(n, RTM_GETNEIGH, NLM_F_REQUEST);
2432 }
2433
2434 static void neigh_app_notify(struct neighbour *n)
2435 {
2436         __neigh_notify(n, RTM_NEWNEIGH, 0);
2437 }
2438
2439 #endif /* CONFIG_ARPD */
2440
2441 #ifdef CONFIG_SYSCTL
2442
2443 static struct neigh_sysctl_table {
2444         struct ctl_table_header *sysctl_header;
2445         ctl_table               neigh_vars[__NET_NEIGH_MAX];
2446         ctl_table               neigh_dev[2];
2447         ctl_table               neigh_neigh_dir[2];
2448         ctl_table               neigh_proto_dir[2];
2449         ctl_table               neigh_root_dir[2];
2450 } neigh_sysctl_template __read_mostly = {
2451         .neigh_vars = {
2452                 {
2453                         .ctl_name       = NET_NEIGH_MCAST_SOLICIT,
2454                         .procname       = "mcast_solicit",
2455                         .maxlen         = sizeof(int),
2456                         .mode           = 0644,
2457                         .proc_handler   = &proc_dointvec,
2458                 },
2459                 {
2460                         .ctl_name       = NET_NEIGH_UCAST_SOLICIT,
2461                         .procname       = "ucast_solicit",
2462                         .maxlen         = sizeof(int),
2463                         .mode           = 0644,
2464                         .proc_handler   = &proc_dointvec,
2465                 },
2466                 {
2467                         .ctl_name       = NET_NEIGH_APP_SOLICIT,
2468                         .procname       = "app_solicit",
2469                         .maxlen         = sizeof(int),
2470                         .mode           = 0644,
2471                         .proc_handler   = &proc_dointvec,
2472                 },
2473                 {
2474                         .ctl_name       = NET_NEIGH_RETRANS_TIME,
2475                         .procname       = "retrans_time",
2476                         .maxlen         = sizeof(int),
2477                         .mode           = 0644,
2478                         .proc_handler   = &proc_dointvec_userhz_jiffies,
2479                 },
2480                 {
2481                         .ctl_name       = NET_NEIGH_REACHABLE_TIME,
2482                         .procname       = "base_reachable_time",
2483                         .maxlen         = sizeof(int),
2484                         .mode           = 0644,
2485                         .proc_handler   = &proc_dointvec_jiffies,
2486                         .strategy       = &sysctl_jiffies,
2487                 },
2488                 {
2489                         .ctl_name       = NET_NEIGH_DELAY_PROBE_TIME,
2490                         .procname       = "delay_first_probe_time",
2491                         .maxlen         = sizeof(int),
2492                         .mode           = 0644,
2493                         .proc_handler   = &proc_dointvec_jiffies,
2494                         .strategy       = &sysctl_jiffies,
2495                 },
2496                 {
2497                         .ctl_name       = NET_NEIGH_GC_STALE_TIME,
2498                         .procname       = "gc_stale_time",
2499                         .maxlen         = sizeof(int),
2500                         .mode           = 0644,
2501                         .proc_handler   = &proc_dointvec_jiffies,
2502                         .strategy       = &sysctl_jiffies,
2503                 },
2504                 {
2505                         .ctl_name       = NET_NEIGH_UNRES_QLEN,
2506                         .procname       = "unres_qlen",
2507                         .maxlen         = sizeof(int),
2508                         .mode           = 0644,
2509                         .proc_handler   = &proc_dointvec,
2510                 },
2511                 {
2512                         .ctl_name       = NET_NEIGH_PROXY_QLEN,
2513                         .procname       = "proxy_qlen",
2514                         .maxlen         = sizeof(int),
2515                         .mode           = 0644,
2516                         .proc_handler   = &proc_dointvec,
2517                 },
2518                 {
2519                         .ctl_name       = NET_NEIGH_ANYCAST_DELAY,
2520                         .procname       = "anycast_delay",
2521                         .maxlen         = sizeof(int),
2522                         .mode           = 0644,
2523                         .proc_handler   = &proc_dointvec_userhz_jiffies,
2524                 },
2525                 {
2526                         .ctl_name       = NET_NEIGH_PROXY_DELAY,
2527                         .procname       = "proxy_delay",
2528                         .maxlen         = sizeof(int),
2529                         .mode           = 0644,
2530                         .proc_handler   = &proc_dointvec_userhz_jiffies,
2531                 },
2532                 {
2533                         .ctl_name       = NET_NEIGH_LOCKTIME,
2534                         .procname       = "locktime",
2535                         .maxlen         = sizeof(int),
2536                         .mode           = 0644,
2537                         .proc_handler   = &proc_dointvec_userhz_jiffies,
2538                 },
2539                 {
2540                         .ctl_name       = NET_NEIGH_GC_INTERVAL,
2541                         .procname       = "gc_interval",
2542                         .maxlen         = sizeof(int),
2543                         .mode           = 0644,
2544                         .proc_handler   = &proc_dointvec_jiffies,
2545                         .strategy       = &sysctl_jiffies,
2546                 },
2547                 {
2548                         .ctl_name       = NET_NEIGH_GC_THRESH1,
2549                         .procname       = "gc_thresh1",
2550                         .maxlen         = sizeof(int),
2551                         .mode           = 0644,
2552                         .proc_handler   = &proc_dointvec,
2553                 },
2554                 {
2555                         .ctl_name       = NET_NEIGH_GC_THRESH2,
2556                         .procname       = "gc_thresh2",
2557                         .maxlen         = sizeof(int),
2558                         .mode           = 0644,
2559                         .proc_handler   = &proc_dointvec,
2560                 },
2561                 {
2562                         .ctl_name       = NET_NEIGH_GC_THRESH3,
2563                         .procname       = "gc_thresh3",
2564                         .maxlen         = sizeof(int),
2565                         .mode           = 0644,
2566                         .proc_handler   = &proc_dointvec,
2567                 },
2568                 {
2569                         .ctl_name       = NET_NEIGH_RETRANS_TIME_MS,
2570                         .procname       = "retrans_time_ms",
2571                         .maxlen         = sizeof(int),
2572                         .mode           = 0644,
2573                         .proc_handler   = &proc_dointvec_ms_jiffies,
2574                         .strategy       = &sysctl_ms_jiffies,
2575                 },
2576                 {
2577                         .ctl_name       = NET_NEIGH_REACHABLE_TIME_MS,
2578                         .procname       = "base_reachable_time_ms",
2579                         .maxlen         = sizeof(int),
2580                         .mode           = 0644,
2581                         .proc_handler   = &proc_dointvec_ms_jiffies,
2582                         .strategy       = &sysctl_ms_jiffies,
2583                 },
2584         },
2585         .neigh_dev = {
2586                 {
2587                         .ctl_name       = NET_PROTO_CONF_DEFAULT,
2588                         .procname       = "default",
2589                         .mode           = 0555,
2590                 },
2591         },
2592         .neigh_neigh_dir = {
2593                 {
2594                         .procname       = "neigh",
2595                         .mode           = 0555,
2596                 },
2597         },
2598         .neigh_proto_dir = {
2599                 {
2600                         .mode           = 0555,
2601                 },
2602         },
2603         .neigh_root_dir = {
2604                 {
2605                         .ctl_name       = CTL_NET,
2606                         .procname       = "net",
2607                         .mode           = 0555,
2608                 },
2609         },
2610 };
2611
2612 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
2613                           int p_id, int pdev_id, char *p_name,
2614                           proc_handler *handler, ctl_handler *strategy)
2615 {
2616         struct neigh_sysctl_table *t = kmalloc(sizeof(*t), GFP_KERNEL);
2617         const char *dev_name_source = NULL;
2618         char *dev_name = NULL;
2619         int err = 0;
2620
2621         if (!t)
2622                 return -ENOBUFS;
2623         memcpy(t, &neigh_sysctl_template, sizeof(*t));
2624         t->neigh_vars[0].data  = &p->mcast_probes;
2625         t->neigh_vars[1].data  = &p->ucast_probes;
2626         t->neigh_vars[2].data  = &p->app_probes;
2627         t->neigh_vars[3].data  = &p->retrans_time;
2628         t->neigh_vars[4].data  = &p->base_reachable_time;
2629         t->neigh_vars[5].data  = &p->delay_probe_time;
2630         t->neigh_vars[6].data  = &p->gc_staletime;
2631         t->neigh_vars[7].data  = &p->queue_len;
2632         t->neigh_vars[8].data  = &p->proxy_qlen;
2633         t->neigh_vars[9].data  = &p->anycast_delay;
2634         t->neigh_vars[10].data = &p->proxy_delay;
2635         t->neigh_vars[11].data = &p->locktime;
2636
2637         if (dev) {
2638                 dev_name_source = dev->name;
2639                 t->neigh_dev[0].ctl_name = dev->ifindex;
2640                 t->neigh_vars[12].procname = NULL;
2641                 t->neigh_vars[13].procname = NULL;
2642                 t->neigh_vars[14].procname = NULL;
2643                 t->neigh_vars[15].procname = NULL;
2644         } else {
2645                 dev_name_source = t->neigh_dev[0].procname;
2646                 t->neigh_vars[12].data = (int *)(p + 1);
2647                 t->neigh_vars[13].data = (int *)(p + 1) + 1;
2648                 t->neigh_vars[14].data = (int *)(p + 1) + 2;
2649                 t->neigh_vars[15].data = (int *)(p + 1) + 3;
2650         }
2651
2652         t->neigh_vars[16].data  = &p->retrans_time;
2653         t->neigh_vars[17].data  = &p->base_reachable_time;
2654
2655         if (handler || strategy) {
2656                 /* RetransTime */
2657                 t->neigh_vars[3].proc_handler = handler;
2658                 t->neigh_vars[3].strategy = strategy;
2659                 t->neigh_vars[3].extra1 = dev;
2660                 /* ReachableTime */
2661                 t->neigh_vars[4].proc_handler = handler;
2662                 t->neigh_vars[4].strategy = strategy;
2663                 t->neigh_vars[4].extra1 = dev;
2664                 /* RetransTime (in milliseconds)*/
2665                 t->neigh_vars[16].proc_handler = handler;
2666                 t->neigh_vars[16].strategy = strategy;
2667                 t->neigh_vars[16].extra1 = dev;
2668                 /* ReachableTime (in milliseconds) */
2669                 t->neigh_vars[17].proc_handler = handler;
2670                 t->neigh_vars[17].strategy = strategy;
2671                 t->neigh_vars[17].extra1 = dev;
2672         }
2673
2674         dev_name = kstrdup(dev_name_source, GFP_KERNEL);
2675         if (!dev_name) {
2676                 err = -ENOBUFS;
2677                 goto free;
2678         }
2679
2680         t->neigh_dev[0].procname = dev_name;
2681
2682         t->neigh_neigh_dir[0].ctl_name = pdev_id;
2683
2684         t->neigh_proto_dir[0].procname = p_name;
2685         t->neigh_proto_dir[0].ctl_name = p_id;
2686
2687         t->neigh_dev[0].child          = t->neigh_vars;
2688         t->neigh_neigh_dir[0].child    = t->neigh_dev;
2689         t->neigh_proto_dir[0].child    = t->neigh_neigh_dir;
2690         t->neigh_root_dir[0].child     = t->neigh_proto_dir;
2691
2692         t->sysctl_header = register_sysctl_table(t->neigh_root_dir, 0);
2693         if (!t->sysctl_header) {
2694                 err = -ENOBUFS;
2695                 goto free_procname;
2696         }
2697         p->sysctl_table = t;
2698         return 0;
2699
2700         /* error path */
2701  free_procname:
2702         kfree(dev_name);
2703  free:
2704         kfree(t);
2705
2706         return err;
2707 }
2708
2709 void neigh_sysctl_unregister(struct neigh_parms *p)
2710 {
2711         if (p->sysctl_table) {
2712                 struct neigh_sysctl_table *t = p->sysctl_table;
2713                 p->sysctl_table = NULL;
2714                 unregister_sysctl_table(t->sysctl_header);
2715                 kfree(t->neigh_dev[0].procname);
2716                 kfree(t);
2717         }
2718 }
2719
2720 #endif  /* CONFIG_SYSCTL */
2721
2722 EXPORT_SYMBOL(__neigh_event_send);
2723 EXPORT_SYMBOL(neigh_changeaddr);
2724 EXPORT_SYMBOL(neigh_compat_output);
2725 EXPORT_SYMBOL(neigh_connected_output);
2726 EXPORT_SYMBOL(neigh_create);
2727 EXPORT_SYMBOL(neigh_delete);
2728 EXPORT_SYMBOL(neigh_destroy);
2729 EXPORT_SYMBOL(neigh_dump_info);
2730 EXPORT_SYMBOL(neigh_event_ns);
2731 EXPORT_SYMBOL(neigh_ifdown);
2732 EXPORT_SYMBOL(neigh_lookup);
2733 EXPORT_SYMBOL(neigh_lookup_nodev);
2734 EXPORT_SYMBOL(neigh_parms_alloc);
2735 EXPORT_SYMBOL(neigh_parms_release);
2736 EXPORT_SYMBOL(neigh_rand_reach_time);
2737 EXPORT_SYMBOL(neigh_resolve_output);
2738 EXPORT_SYMBOL(neigh_table_clear);
2739 EXPORT_SYMBOL(neigh_table_init);
2740 EXPORT_SYMBOL(neigh_table_init_no_netlink);
2741 EXPORT_SYMBOL(neigh_update);
2742 EXPORT_SYMBOL(pneigh_enqueue);
2743 EXPORT_SYMBOL(pneigh_lookup);
2744
2745 #ifdef CONFIG_ARPD
2746 EXPORT_SYMBOL(neigh_app_ns);
2747 #endif
2748 #ifdef CONFIG_SYSCTL
2749 EXPORT_SYMBOL(neigh_sysctl_register);
2750 EXPORT_SYMBOL(neigh_sysctl_unregister);
2751 #endif