net/core/neighbour.c

   1 /*
   2  *      Generic address resolution entity
   3  *
   4  *      Authors:
   5  *      Pedro Roque             <roque@di.fc.ul.pt>
   6  *      Alexey Kuznetsov        <kuznet@ms2.inr.ac.ru>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  *
  13  *      Fixes:
  14  *      Vitaly E. Lavrov        releasing NULL neighbor in neigh_add.
  15  *      Harald Welte            Add neighbour cache statistics like rtstat
  16  */
  17
  18 #include <linux/types.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/socket.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/proc_fs.h>
  24 #ifdef CONFIG_SYSCTL
  25 #include <linux/sysctl.h>
  26 #endif
  27 #include <linux/times.h>
  28 #include <net/neighbour.h>
  29 #include <net/dst.h>
  30 #include <net/sock.h>
  31 #include <net/netevent.h>
  32 #include <net/netlink.h>
  33 #include <linux/rtnetlink.h>
  34 #include <linux/random.h>
  35 #include <linux/string.h>
  36
  37 #define NEIGH_DEBUG 1
  38
  39 #define NEIGH_PRINTK(x...) printk(x)
  40 #define NEIGH_NOPRINTK(x...) do { ; } while(0)
  41 #define NEIGH_PRINTK0 NEIGH_PRINTK
  42 #define NEIGH_PRINTK1 NEIGH_NOPRINTK
  43 #define NEIGH_PRINTK2 NEIGH_NOPRINTK
  44
  45 #if NEIGH_DEBUG >= 1
  46 #undef NEIGH_PRINTK1
  47 #define NEIGH_PRINTK1 NEIGH_PRINTK
  48 #endif
  49 #if NEIGH_DEBUG >= 2
  50 #undef NEIGH_PRINTK2
  51 #define NEIGH_PRINTK2 NEIGH_PRINTK
  52 #endif
  53
  54 #define PNEIGH_HASHMASK         0xF
  55
  56 static void neigh_timer_handler(unsigned long arg);
  57 #ifdef CONFIG_ARPD
  58 static void neigh_app_notify(struct neighbour *n);
  59 #endif
  60 static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
  61 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
  62
  63 static struct neigh_table *neigh_tables;
  64 #ifdef CONFIG_PROC_FS
  65 static const struct file_operations neigh_stat_seq_fops;
  66 #endif
  67
  68 /*
  69    Neighbour hash table buckets are protected with rwlock tbl->lock.
  70
  71    - All the scans/updates to hash buckets MUST be made under this lock.
  72    - NOTHING clever should be made under this lock: no callbacks
  73      to protocol backends, no attempts to send something to network.
  74      It will result in deadlocks, if backend/driver wants to use neighbour
  75      cache.
  76    - If the entry requires some non-trivial actions, increase
  77      its reference count and release table lock.
  78
  79    Neighbour entries are protected:
  80    - with reference count.
  81    - with rwlock neigh->lock
  82
  83    Reference count prevents destruction.
  84
  85    neigh->lock mainly serializes ll address data and its validity state.
  86    However, the same lock is used to protect another entry fields:
  87     - timer
  88     - resolution queue
  89
  90    Again, nothing clever shall be made under neigh->lock,
  91    the most complicated procedure, which we allow is dev->hard_header.
  92    It is supposed, that dev->hard_header is simplistic and does
  93    not make callbacks to neighbour tables.
  94
  95    The last lock is neigh_tbl_lock. It is pure SMP lock, protecting
  96    list of neighbour tables. This list is used only in process context,
  97  */
  98
  99 static DEFINE_RWLOCK(neigh_tbl_lock);
 100
 101 static int neigh_blackhole(struct sk_buff *skb)
 102 {
 103         kfree_skb(skb);
 104         return -ENETDOWN;
 105 }
 106
 107 /*
 108  * It is random distribution in the interval (1/2)*base...(3/2)*base.
 109  * It corresponds to default IPv6 settings and is not overridable,
 110  * because it is really reasonable choice.
 111  */
 112
 113 unsigned long neigh_rand_reach_time(unsigned long base)
 114 {
 115         return (base ? (net_random() % base) + (base >> 1) : 0);
 116 }
 117
 118
 119 static int neigh_forced_gc(struct neigh_table *tbl)
 120 {
 121         int shrunk = 0;
 122         int i;
 123
 124         NEIGH_CACHE_STAT_INC(tbl, forced_gc_runs);
 125
 126         write_lock_bh(&tbl->lock);
 127         for (i = 0; i <= tbl->hash_mask; i++) {
 128                 struct neighbour *n, **np;
 129
 130                 np = &tbl->hash_buckets[i];
 131                 while ((n = *np) != NULL) {
 132                         /* Neighbour record may be discarded if:
 133                          * - nobody refers to it.
 134                          * - it is not permanent
 135                          */
 136                         write_lock(&n->lock);
 137                         if (atomic_read(&n->refcnt) == 1 &&
 138                             !(n->nud_state & NUD_PERMANENT)) {
 139                                 *np     = n->next;
 140                                 n->dead = 1;
 141                                 shrunk  = 1;
 142                                 write_unlock(&n->lock);
 143                                 if (n->parms->neigh_cleanup)
 144                                         n->parms->neigh_cleanup(n);
 145                                 neigh_release(n);
 146                                 continue;
 147                         }
 148                         write_unlock(&n->lock);
 149                         np = &n->next;
 150                 }
 151         }
 152
 153         tbl->last_flush = jiffies;
 154
 155         write_unlock_bh(&tbl->lock);
 156
 157         return shrunk;
 158 }
 159
 160 static int neigh_del_timer(struct neighbour *n)
 161 {
 162         if ((n->nud_state & NUD_IN_TIMER) &&
 163             del_timer(&n->timer)) {
 164                 neigh_release(n);
 165                 return 1;
 166         }
 167         return 0;
 168 }
 169
 170 static void pneigh_queue_purge(struct sk_buff_head *list)
 171 {
 172         struct sk_buff *skb;
 173
 174         while ((skb = skb_dequeue(list)) != NULL) {
 175                 dev_put(skb->dev);
 176                 kfree_skb(skb);
 177         }
 178 }
 179
 180 static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev)
 181 {
 182         int i;
 183
 184         for (i = 0; i <= tbl->hash_mask; i++) {
 185                 struct neighbour *n, **np = &tbl->hash_buckets[i];
 186
 187                 while ((n = *np) != NULL) {
 188                         if (dev && n->dev != dev) {
 189                                 np = &n->next;
 190                                 continue;
 191                         }
 192                         *np = n->next;
 193                         write_lock(&n->lock);
 194                         neigh_del_timer(n);
 195                         n->dead = 1;
 196
 197                         if (atomic_read(&n->refcnt) != 1) {
 198                                 /* The most unpleasant situation.
 199                                    We must destroy neighbour entry,
 200                                    but someone still uses it.
 201
 202                                    The destroy will be delayed until
 203                                    the last user releases us, but
 204                                    we must kill timers etc. and move
 205                                    it to safe state.
 206                                  */
 207                                 skb_queue_purge(&n->arp_queue);
 208                                 n->output = neigh_blackhole;
 209                                 if (n->nud_state & NUD_VALID)
 210                                         n->nud_state = NUD_NOARP;
 211                                 else
 212                                         n->nud_state = NUD_NONE;
 213                                 NEIGH_PRINTK2("neigh %p is stray.\n", n);
 214                         }
 215                         write_unlock(&n->lock);
 216                         if (n->parms->neigh_cleanup)
 217                                 n->parms->neigh_cleanup(n);
 218                         neigh_release(n);
 219                 }
 220         }
 221 }
 222
 223 void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev)
 224 {
 225         write_lock_bh(&tbl->lock);
 226         neigh_flush_dev(tbl, dev);
 227         write_unlock_bh(&tbl->lock);
 228 }
 229
 230 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 231 {
 232         write_lock_bh(&tbl->lock);
 233         neigh_flush_dev(tbl, dev);
 234         pneigh_ifdown(tbl, dev);
 235         write_unlock_bh(&tbl->lock);
 236
 237         del_timer_sync(&tbl->proxy_timer);
 238         pneigh_queue_purge(&tbl->proxy_queue);
 239         return 0;
 240 }
 241
 242 static struct neighbour *neigh_alloc(struct neigh_table *tbl)
 243 {
 244         struct neighbour *n = NULL;
 245         unsigned long now = jiffies;
 246         int entries;
 247
 248         entries = atomic_inc_return(&tbl->entries) - 1;
 249         if (entries >= tbl->gc_thresh3 ||
 250             (entries >= tbl->gc_thresh2 &&
 251              time_after(now, tbl->last_flush + 5 * HZ))) {
 252                 if (!neigh_forced_gc(tbl) &&
 253                     entries >= tbl->gc_thresh3)
 254                         goto out_entries;
 255         }
 256
 257         n = kmem_cache_zalloc(tbl->kmem_cachep, GFP_ATOMIC);
 258         if (!n)
 259                 goto out_entries;
 260
 261         skb_queue_head_init(&n->arp_queue);
 262         rwlock_init(&n->lock);
 263         n->updated        = n->used = now;
 264         n->nud_state      = NUD_NONE;
 265         n->output         = neigh_blackhole;
 266         n->parms          = neigh_parms_clone(&tbl->parms);
 267         init_timer(&n->timer);
 268         n->timer.function = neigh_timer_handler;
 269         n->timer.data     = (unsigned long)n;
 270
 271         NEIGH_CACHE_STAT_INC(tbl, allocs);
 272         n->tbl            = tbl;
 273         atomic_set(&n->refcnt, 1);
 274         n->dead           = 1;
 275 out:
 276         return n;
 277
 278 out_entries:
 279         atomic_dec(&tbl->entries);
 280         goto out;
 281 }
 282
 283 static struct neighbour **neigh_hash_alloc(unsigned int entries)
 284 {
 285         unsigned long size = entries * sizeof(struct neighbour *);
 286         struct neighbour **ret;
 287
 288         if (size <= PAGE_SIZE) {
 289                 ret = kzalloc(size, GFP_ATOMIC);
 290         } else {
 291                 ret = (struct neighbour **)
 292                       __get_free_pages(GFP_ATOMIC|__GFP_ZERO, get_order(size));
 293         }
 294         return ret;
 295 }
 296
 297 static void neigh_hash_free(struct neighbour **hash, unsigned int entries)
 298 {
 299         unsigned long size = entries * sizeof(struct neighbour *);
 300
 301         if (size <= PAGE_SIZE)
 302                 kfree(hash);
 303         else
 304                 free_pages((unsigned long)hash, get_order(size));
 305 }
 306
 307 static void neigh_hash_grow(struct neigh_table *tbl, unsigned long new_entries)
 308 {
 309         struct neighbour **new_hash, **old_hash;
 310         unsigned int i, new_hash_mask, old_entries;
 311
 312         NEIGH_CACHE_STAT_INC(tbl, hash_grows);
 313
 314         BUG_ON(new_entries & (new_entries - 1));
 315         new_hash = neigh_hash_alloc(new_entries);
 316         if (!new_hash)
 317                 return;
 318
 319         old_entries = tbl->hash_mask + 1;
 320         new_hash_mask = new_entries - 1;
 321         old_hash = tbl->hash_buckets;
 322
 323         get_random_bytes(&tbl->hash_rnd, sizeof(tbl->hash_rnd));
 324         for (i = 0; i < old_entries; i++) {
 325                 struct neighbour *n, *next;
 326
 327                 for (n = old_hash[i]; n; n = next) {
 328                         unsigned int hash_val = tbl->hash(n->primary_key, n->dev);
 329
 330                         hash_val &= new_hash_mask;
 331                         next = n->next;
 332
 333                         n->next = new_hash[hash_val];
 334                         new_hash[hash_val] = n;
 335                 }
 336         }
 337         tbl->hash_buckets = new_hash;
 338         tbl->hash_mask = new_hash_mask;
 339
 340         neigh_hash_free(old_hash, old_entries);
 341 }
 342
 343 struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
 344                                struct net_device *dev)
 345 {
 346         struct neighbour *n;
 347         int key_len = tbl->key_len;
 348         u32 hash_val = tbl->hash(pkey, dev);
 349
 350         NEIGH_CACHE_STAT_INC(tbl, lookups);
 351
 352         read_lock_bh(&tbl->lock);
 353         for (n = tbl->hash_buckets[hash_val & tbl->hash_mask]; n; n = n->next) {
 354                 if (dev == n->dev && !memcmp(n->primary_key, pkey, key_len)) {
 355                         neigh_hold(n);
 356                         NEIGH_CACHE_STAT_INC(tbl, hits);
 357                         break;
 358                 }
 359         }
 360         read_unlock_bh(&tbl->lock);
 361         return n;
 362 }
 363
 364 struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, const void *pkey)
 365 {
 366         struct neighbour *n;
 367         int key_len = tbl->key_len;
 368         u32 hash_val = tbl->hash(pkey, NULL);
 369
 370         NEIGH_CACHE_STAT_INC(tbl, lookups);
 371
 372         read_lock_bh(&tbl->lock);
 373         for (n = tbl->hash_buckets[hash_val & tbl->hash_mask]; n; n = n->next) {
 374                 if (!memcmp(n->primary_key, pkey, key_len)) {
 375                         neigh_hold(n);
 376                         NEIGH_CACHE_STAT_INC(tbl, hits);
 377                         break;
 378                 }
 379         }
 380         read_unlock_bh(&tbl->lock);
 381         return n;
 382 }
 383
 384 struct neighbour *neigh_create(struct neigh_table *tbl, const void *pkey,
 385                                struct net_device *dev)
 386 {
 387         u32 hash_val;
 388         int key_len = tbl->key_len;
 389         int error;
 390         struct neighbour *n1, *rc, *n = neigh_alloc(tbl);
 391
 392         if (!n) {
 393                 rc = ERR_PTR(-ENOBUFS);
 394                 goto out;
 395         }
 396
 397         memcpy(n->primary_key, pkey, key_len);
 398         n->dev = dev;
 399         dev_hold(dev);
 400
 401         /* Protocol specific setup. */
 402         if (tbl->constructor && (error = tbl->constructor(n)) < 0) {
 403                 rc = ERR_PTR(error);
 404                 goto out_neigh_release;
 405         }
 406
 407         /* Device specific setup. */
 408         if (n->parms->neigh_setup &&
 409             (error = n->parms->neigh_setup(n)) < 0) {
 410                 rc = ERR_PTR(error);
 411                 goto out_neigh_release;
 412         }
 413
 414         n->confirmed = jiffies - (n->parms->base_reachable_time << 1);
 415
 416         write_lock_bh(&tbl->lock);
 417
 418         if (atomic_read(&tbl->entries) > (tbl->hash_mask + 1))
 419                 neigh_hash_grow(tbl, (tbl->hash_mask + 1) << 1);
 420
 421         hash_val = tbl->hash(pkey, dev) & tbl->hash_mask;
 422
 423         if (n->parms->dead) {
 424                 rc = ERR_PTR(-EINVAL);
 425                 goto out_tbl_unlock;
 426         }
 427
 428         for (n1 = tbl->hash_buckets[hash_val]; n1; n1 = n1->next) {
 429                 if (dev == n1->dev && !memcmp(n1->primary_key, pkey, key_len)) {
 430                         neigh_hold(n1);
 431                         rc = n1;
 432                         goto out_tbl_unlock;
 433                 }
 434         }
 435
 436         n->next = tbl->hash_buckets[hash_val];
 437         tbl->hash_buckets[hash_val] = n;
 438         n->dead = 0;
 439         neigh_hold(n);
 440         write_unlock_bh(&tbl->lock);
 441         NEIGH_PRINTK2("neigh %p is created.\n", n);
 442         rc = n;
 443 out:
 444         return rc;
 445 out_tbl_unlock:
 446         write_unlock_bh(&tbl->lock);
 447 out_neigh_release:
 448         neigh_release(n);
 449         goto out;
 450 }
 451
 452 struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl, const void *pkey,
 453                                     struct net_device *dev, int creat)
 454 {
 455         struct pneigh_entry *n;
 456         int key_len = tbl->key_len;
 457         u32 hash_val = *(u32 *)(pkey + key_len - 4);
 458
 459         hash_val ^= (hash_val >> 16);
 460         hash_val ^= hash_val >> 8;
 461         hash_val ^= hash_val >> 4;
 462         hash_val &= PNEIGH_HASHMASK;
 463
 464         read_lock_bh(&tbl->lock);
 465
 466         for (n = tbl->phash_buckets[hash_val]; n; n = n->next) {
 467                 if (!memcmp(n->key, pkey, key_len) &&
 468                     (n->dev == dev || !n->dev)) {
 469                         read_unlock_bh(&tbl->lock);
 470                         goto out;
 471                 }
 472         }
 473         read_unlock_bh(&tbl->lock);
 474         n = NULL;
 475         if (!creat)
 476                 goto out;
 477
 478         n = kmalloc(sizeof(*n) + key_len, GFP_KERNEL);
 479         if (!n)
 480                 goto out;
 481
 482         memcpy(n->key, pkey, key_len);
 483         n->dev = dev;
 484         if (dev)
 485                 dev_hold(dev);
 486
 487         if (tbl->pconstructor && tbl->pconstructor(n)) {
 488                 if (dev)
 489                         dev_put(dev);
 490                 kfree(n);
 491                 n = NULL;
 492                 goto out;
 493         }
 494
 495         write_lock_bh(&tbl->lock);
 496         n->next = tbl->phash_buckets[hash_val];
 497         tbl->phash_buckets[hash_val] = n;
 498         write_unlock_bh(&tbl->lock);
 499 out:
 500         return n;
 501 }
 502
 503
 504 int pneigh_delete(struct neigh_table *tbl, const void *pkey,
 505                   struct net_device *dev)
 506 {
 507         struct pneigh_entry *n, **np;
 508         int key_len = tbl->key_len;
 509         u32 hash_val = *(u32 *)(pkey + key_len - 4);
 510
 511         hash_val ^= (hash_val >> 16);
 512         hash_val ^= hash_val >> 8;
 513         hash_val ^= hash_val >> 4;
 514         hash_val &= PNEIGH_HASHMASK;
 515
 516         write_lock_bh(&tbl->lock);
 517         for (np = &tbl->phash_buckets[hash_val]; (n = *np) != NULL;
 518              np = &n->next) {
 519                 if (!memcmp(n->key, pkey, key_len) && n->dev == dev) {
 520                         *np = n->next;
 521                         write_unlock_bh(&tbl->lock);
 522                         if (tbl->pdestructor)
 523                                 tbl->pdestructor(n);
 524                         if (n->dev)
 525                                 dev_put(n->dev);
 526                         kfree(n);
 527                         return 0;
 528                 }
 529         }
 530         write_unlock_bh(&tbl->lock);
 531         return -ENOENT;
 532 }
 533
 534 static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 535 {
 536         struct pneigh_entry *n, **np;
 537         u32 h;
 538
 539         for (h = 0; h <= PNEIGH_HASHMASK; h++) {
 540                 np = &tbl->phash_buckets[h];
 541                 while ((n = *np) != NULL) {
 542                         if (!dev || n->dev == dev) {
 543                                 *np = n->next;
 544                                 if (tbl->pdestructor)
 545                                         tbl->pdestructor(n);
 546                                 if (n->dev)
 547                                         dev_put(n->dev);
 548                                 kfree(n);
 549                                 continue;
 550                         }
 551                         np = &n->next;
 552                 }
 553         }
 554         return -ENOENT;
 555 }
 556
 557
 558 /*
 559  *      neighbour must already be out of the table;
 560  *
 561  */
 562 void neigh_destroy(struct neighbour *neigh)
 563 {
 564         struct hh_cache *hh;
 565
 566         NEIGH_CACHE_STAT_INC(neigh->tbl, destroys);
 567
 568         if (!neigh->dead) {
 569                 printk(KERN_WARNING
 570                        "Destroying alive neighbour %p\n", neigh);
 571                 dump_stack();
 572                 return;
 573         }
 574
 575         if (neigh_del_timer(neigh))
 576                 printk(KERN_WARNING "Impossible event.\n");
 577
 578         while ((hh = neigh->hh) != NULL) {
 579                 neigh->hh = hh->hh_next;
 580                 hh->hh_next = NULL;
 581
 582                 write_seqlock_bh(&hh->hh_lock);
 583                 hh->hh_output = neigh_blackhole;
 584                 write_sequnlock_bh(&hh->hh_lock);
 585                 if (atomic_dec_and_test(&hh->hh_refcnt))
 586                         kfree(hh);
 587         }
 588
 589         skb_queue_purge(&neigh->arp_queue);
 590
 591         dev_put(neigh->dev);
 592         neigh_parms_put(neigh->parms);
 593
 594         NEIGH_PRINTK2("neigh %p is destroyed.\n", neigh);
 595
 596         atomic_dec(&neigh->tbl->entries);
 597         kmem_cache_free(neigh->tbl->kmem_cachep, neigh);
 598 }
 599
 600 /* Neighbour state is suspicious;
 601    disable fast path.
 602
 603    Called with write_locked neigh.
 604  */
 605 static void neigh_suspect(struct neighbour *neigh)
 606 {
 607         struct hh_cache *hh;
 608
 609         NEIGH_PRINTK2("neigh %p is suspected.\n", neigh);
 610
 611         neigh->output = neigh->ops->output;
 612
 613         for (hh = neigh->hh; hh; hh = hh->hh_next)
 614                 hh->hh_output = neigh->ops->output;
 615 }
 616
 617 /* Neighbour state is OK;
 618    enable fast path.
 619
 620    Called with write_locked neigh.
 621  */
 622 static void neigh_connect(struct neighbour *neigh)
 623 {
 624         struct hh_cache *hh;
 625
 626         NEIGH_PRINTK2("neigh %p is connected.\n", neigh);
 627
 628         neigh->output = neigh->ops->connected_output;
 629
 630         for (hh = neigh->hh; hh; hh = hh->hh_next)
 631                 hh->hh_output = neigh->ops->hh_output;
 632 }
 633
 634 static void neigh_periodic_timer(unsigned long arg)
 635 {
 636         struct neigh_table *tbl = (struct neigh_table *)arg;
 637         struct neighbour *n, **np;
 638         unsigned long expire, now = jiffies;
 639
 640         NEIGH_CACHE_STAT_INC(tbl, periodic_gc_runs);
 641
 642         write_lock(&tbl->lock);
 643
 644         /*
 645          *      periodically recompute ReachableTime from random function
 646          */
 647
 648         if (time_after(now, tbl->last_rand + 300 * HZ)) {
 649                 struct neigh_parms *p;
 650                 tbl->last_rand = now;
 651                 for (p = &tbl->parms; p; p = p->next)
 652                         p->reachable_time =
 653                                 neigh_rand_reach_time(p->base_reachable_time);
 654         }
 655
 656         np = &tbl->hash_buckets[tbl->hash_chain_gc];
 657         tbl->hash_chain_gc = ((tbl->hash_chain_gc + 1) & tbl->hash_mask);
 658
 659         while ((n = *np) != NULL) {
 660                 unsigned int state;
 661
 662                 write_lock(&n->lock);
 663
 664                 state = n->nud_state;
 665                 if (state & (NUD_PERMANENT | NUD_IN_TIMER)) {
 666                         write_unlock(&n->lock);
 667                         goto next_elt;
 668                 }
 669
 670                 if (time_before(n->used, n->confirmed))
 671                         n->used = n->confirmed;
 672
 673                 if (atomic_read(&n->refcnt) == 1 &&
 674                     (state == NUD_FAILED ||
 675                      time_after(now, n->used + n->parms->gc_staletime))) {
 676                         *np = n->next;
 677                         n->dead = 1;
 678                         write_unlock(&n->lock);
 679                         if (n->parms->neigh_cleanup)
 680                                 n->parms->neigh_cleanup(n);
 681                         neigh_release(n);
 682                         continue;
 683                 }
 684                 write_unlock(&n->lock);
 685
 686 next_elt:
 687                 np = &n->next;
 688         }
 689
 690         /* Cycle through all hash buckets every base_reachable_time/2 ticks.
 691          * ARP entry timeouts range from 1/2 base_reachable_time to 3/2
 692          * base_reachable_time.
 693          */
 694         expire = tbl->parms.base_reachable_time >> 1;
 695         expire /= (tbl->hash_mask + 1);
 696         if (!expire)
 697                 expire = 1;
 698
 699         if (expire>HZ)
 700                 mod_timer(&tbl->gc_timer, round_jiffies(now + expire));
 701         else
 702                 mod_timer(&tbl->gc_timer, now + expire);
 703
 704         write_unlock(&tbl->lock);
 705 }
 706
 707 static __inline__ int neigh_max_probes(struct neighbour *n)
 708 {
 709         struct neigh_parms *p = n->parms;
 710         return (n->nud_state & NUD_PROBE ?
 711                 p->ucast_probes :
 712                 p->ucast_probes + p->app_probes + p->mcast_probes);
 713 }
 714
 715 static inline void neigh_add_timer(struct neighbour *n, unsigned long when)
 716 {
 717         if (unlikely(mod_timer(&n->timer, when))) {
 718                 printk("NEIGH: BUG, double timer add, state is %x\n",
 719                        n->nud_state);
 720                 dump_stack();
 721         }
 722 }
 723
 724 /* Called when a timer expires for a neighbour entry. */
 725
 726 static void neigh_timer_handler(unsigned long arg)
 727 {
 728         unsigned long now, next;
 729         struct neighbour *neigh = (struct neighbour *)arg;
 730         unsigned state;
 731         int notify = 0;
 732
 733         write_lock(&neigh->lock);
 734
 735         state = neigh->nud_state;
 736         now = jiffies;
 737         next = now + HZ;
 738
 739         if (!(state & NUD_IN_TIMER)) {
 740 #ifndef CONFIG_SMP
 741                 printk(KERN_WARNING "neigh: timer & !nud_in_timer\n");
 742 #endif
 743                 goto out;
 744         }
 745
 746         if (state & NUD_REACHABLE) {
 747                 if (time_before_eq(now,
 748                                    neigh->confirmed + neigh->parms->reachable_time)) {
 749                         NEIGH_PRINTK2("neigh %p is still alive.\n", neigh);
 750                         next = neigh->confirmed + neigh->parms->reachable_time;
 751                 } else if (time_before_eq(now,
 752                                           neigh->used + neigh->parms->delay_probe_time)) {
 753                         NEIGH_PRINTK2("neigh %p is delayed.\n", neigh);
 754                         neigh->nud_state = NUD_DELAY;
 755                         neigh->updated = jiffies;
 756                         neigh_suspect(neigh);
 757                         next = now + neigh->parms->delay_probe_time;
 758                 } else {
 759                         NEIGH_PRINTK2("neigh %p is suspected.\n", neigh);
 760                         neigh->nud_state = NUD_STALE;
 761                         neigh->updated = jiffies;
 762                         neigh_suspect(neigh);
 763                         notify = 1;
 764                 }
 765         } else if (state & NUD_DELAY) {
 766                 if (time_before_eq(now,
 767                                    neigh->confirmed + neigh->parms->delay_probe_time)) {
 768                         NEIGH_PRINTK2("neigh %p is now reachable.\n", neigh);
 769                         neigh->nud_state = NUD_REACHABLE;
 770                         neigh->updated = jiffies;
 771                         neigh_connect(neigh);
 772                         notify = 1;
 773                         next = neigh->confirmed + neigh->parms->reachable_time;
 774                 } else {
 775                         NEIGH_PRINTK2("neigh %p is probed.\n", neigh);
 776                         neigh->nud_state = NUD_PROBE;
 777                         neigh->updated = jiffies;
 778                         atomic_set(&neigh->probes, 0);
 779                         next = now + neigh->parms->retrans_time;
 780                 }
 781         } else {
 782                 /* NUD_PROBE|NUD_INCOMPLETE */
 783                 next = now + neigh->parms->retrans_time;
 784         }
 785
 786         if ((neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) &&
 787             atomic_read(&neigh->probes) >= neigh_max_probes(neigh)) {
 788                 struct sk_buff *skb;
 789
 790                 neigh->nud_state = NUD_FAILED;
 791                 neigh->updated = jiffies;
 792                 notify = 1;
 793                 NEIGH_CACHE_STAT_INC(neigh->tbl, res_failed);
 794                 NEIGH_PRINTK2("neigh %p is failed.\n", neigh);
 795
 796                 /* It is very thin place. report_unreachable is very complicated
 797                    routine. Particularly, it can hit the same neighbour entry!
 798
 799                    So that, we try to be accurate and avoid dead loop. --ANK
 800                  */
 801                 while (neigh->nud_state == NUD_FAILED &&
 802                        (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
 803                         write_unlock(&neigh->lock);
 804                         neigh->ops->error_report(neigh, skb);
 805                         write_lock(&neigh->lock);
 806                 }
 807                 skb_queue_purge(&neigh->arp_queue);
 808         }
 809
 810         if (neigh->nud_state & NUD_IN_TIMER) {
 811                 if (time_before(next, jiffies + HZ/2))
 812                         next = jiffies + HZ/2;
 813                 if (!mod_timer(&neigh->timer, next))
 814                         neigh_hold(neigh);
 815         }
 816         if (neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) {
 817                 struct sk_buff *skb = skb_peek(&neigh->arp_queue);
 818                 /* keep skb alive even if arp_queue overflows */
 819                 if (skb)
 820                         skb_get(skb);
 821                 write_unlock(&neigh->lock);
 822                 neigh->ops->solicit(neigh, skb);
 823                 atomic_inc(&neigh->probes);
 824                 if (skb)
 825                         kfree_skb(skb);
 826         } else {
 827 out:
 828                 write_unlock(&neigh->lock);
 829         }
 830         if (notify)
 831                 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
 832
 833 #ifdef CONFIG_ARPD
 834         if (notify && neigh->parms->app_probes)
 835                 neigh_app_notify(neigh);
 836 #endif
 837         neigh_release(neigh);
 838 }
 839
 840 int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 841 {
 842         int rc;
 843         unsigned long now;
 844
 845         write_lock_bh(&neigh->lock);
 846
 847         rc = 0;
 848         if (neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE))
 849                 goto out_unlock_bh;
 850
 851         now = jiffies;
 852
 853         if (!(neigh->nud_state & (NUD_STALE | NUD_INCOMPLETE))) {
 854                 if (neigh->parms->mcast_probes + neigh->parms->app_probes) {
 855                         atomic_set(&neigh->probes, neigh->parms->ucast_probes);
 856                         neigh->nud_state     = NUD_INCOMPLETE;
 857                         neigh->updated = jiffies;
 858                         neigh_hold(neigh);
 859                         neigh_add_timer(neigh, now + 1);
 860                 } else {
 861                         neigh->nud_state = NUD_FAILED;
 862                         neigh->updated = jiffies;
 863                         write_unlock_bh(&neigh->lock);
 864
 865                         if (skb)
 866                                 kfree_skb(skb);
 867                         return 1;
 868                 }
 869         } else if (neigh->nud_state & NUD_STALE) {
 870                 NEIGH_PRINTK2("neigh %p is delayed.\n", neigh);
 871                 neigh_hold(neigh);
 872                 neigh->nud_state = NUD_DELAY;
 873                 neigh->updated = jiffies;
 874                 neigh_add_timer(neigh,
 875                                 jiffies + neigh->parms->delay_probe_time);
 876         }
 877
 878         if (neigh->nud_state == NUD_INCOMPLETE) {
 879                 if (skb) {
 880                         if (skb_queue_len(&neigh->arp_queue) >=
 881                             neigh->parms->queue_len) {
 882                                 struct sk_buff *buff;
 883                                 buff = neigh->arp_queue.next;
 884                                 __skb_unlink(buff, &neigh->arp_queue);
 885                                 kfree_skb(buff);
 886                         }
 887                         __skb_queue_tail(&neigh->arp_queue, skb);
 888                 }
 889                 rc = 1;
 890         }
 891 out_unlock_bh:
 892         write_unlock_bh(&neigh->lock);
 893         return rc;
 894 }
 895
 896 static void neigh_update_hhs(struct neighbour *neigh)
 897 {
 898         struct hh_cache *hh;
 899         void (*update)(struct hh_cache*, struct net_device*, unsigned char *) =
 900                 neigh->dev->header_cache_update;
 901
 902         if (update) {
 903                 for (hh = neigh->hh; hh; hh = hh->hh_next) {
 904                         write_seqlock_bh(&hh->hh_lock);
 905                         update(hh, neigh->dev, neigh->ha);
 906                         write_sequnlock_bh(&hh->hh_lock);
 907                 }
 908         }
 909 }
 910
 911
 912
 913 /* Generic update routine.
 914    -- lladdr is new lladdr or NULL, if it is not supplied.
 915    -- new    is new state.
 916    -- flags
 917         NEIGH_UPDATE_F_OVERRIDE allows to override existing lladdr,
 918                                 if it is different.
 919         NEIGH_UPDATE_F_WEAK_OVERRIDE will suspect existing "connected"
 920                                 lladdr instead of overriding it
 921                                 if it is different.
 922                                 It also allows to retain current state
 923                                 if lladdr is unchanged.
 924         NEIGH_UPDATE_F_ADMIN    means that the change is administrative.
 925
 926         NEIGH_UPDATE_F_OVERRIDE_ISROUTER allows to override existing
 927                                 NTF_ROUTER flag.
 928         NEIGH_UPDATE_F_ISROUTER indicates if the neighbour is known as
 929                                 a router.
 930
 931    Caller MUST hold reference count on the entry.
 932  */
 933
 934 int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
 935                  u32 flags)
 936 {
 937         u8 old;
 938         int err;
 939         int notify = 0;
 940         struct net_device *dev;
 941         int update_isrouter = 0;
 942
 943         write_lock_bh(&neigh->lock);
 944
 945         dev    = neigh->dev;
 946         old    = neigh->nud_state;
 947         err    = -EPERM;
 948
 949         if (!(flags & NEIGH_UPDATE_F_ADMIN) &&
 950             (old & (NUD_NOARP | NUD_PERMANENT)))
 951                 goto out;
 952
 953         if (!(new & NUD_VALID)) {
 954                 neigh_del_timer(neigh);
 955                 if (old & NUD_CONNECTED)
 956                         neigh_suspect(neigh);
 957                 neigh->nud_state = new;
 958                 err = 0;
 959                 notify = old & NUD_VALID;
 960                 goto out;
 961         }
 962
 963         /* Compare new lladdr with cached one */
 964         if (!dev->addr_len) {
 965                 /* First case: device needs no address. */
 966                 lladdr = neigh->ha;
 967         } else if (lladdr) {
 968                 /* The second case: if something is already cached
 969                    and a new address is proposed:
 970                    - compare new & old
 971                    - if they are different, check override flag
 972                  */
 973                 if ((old & NUD_VALID) &&
 974                     !memcmp(lladdr, neigh->ha, dev->addr_len))
 975                         lladdr = neigh->ha;
 976         } else {
 977                 /* No address is supplied; if we know something,
 978                    use it, otherwise discard the request.
 979                  */
 980                 err = -EINVAL;
 981                 if (!(old & NUD_VALID))
 982                         goto out;
 983                 lladdr = neigh->ha;
 984         }
 985
 986         if (new & NUD_CONNECTED)
 987                 neigh->confirmed = jiffies;
 988         neigh->updated = jiffies;
 989
 990         /* If entry was valid and address is not changed,
 991            do not change entry state, if new one is STALE.
 992          */
 993         err = 0;
 994         update_isrouter = flags & NEIGH_UPDATE_F_OVERRIDE_ISROUTER;
 995         if (old & NUD_VALID) {
 996                 if (lladdr != neigh->ha && !(flags & NEIGH_UPDATE_F_OVERRIDE)) {
 997                         update_isrouter = 0;
 998                         if ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) &&
 999                             (old & NUD_CONNECTED)) {
1000                                 lladdr = neigh->ha;
1001                                 new = NUD_STALE;
1002                         } else
1003                                 goto out;
1004                 } else {
1005                         if (lladdr == neigh->ha && new == NUD_STALE &&
1006                             ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) ||
1007                              (old & NUD_CONNECTED))
1008                             )
1009                                 new = old;
1010                 }
1011         }
1012
1013         if (new != old) {
1014                 neigh_del_timer(neigh);
1015                 if (new & NUD_IN_TIMER) {
1016                         neigh_hold(neigh);
1017                         neigh_add_timer(neigh, (jiffies +
1018                                                 ((new & NUD_REACHABLE) ?
1019                                                  neigh->parms->reachable_time :
1020                                                  0)));
1021                 }
1022                 neigh->nud_state = new;
1023         }
1024
1025         if (lladdr != neigh->ha) {
1026                 memcpy(&neigh->ha, lladdr, dev->addr_len);
1027                 neigh_update_hhs(neigh);
1028                 if (!(new & NUD_CONNECTED))
1029                         neigh->confirmed = jiffies -
1030                                       (neigh->parms->base_reachable_time << 1);
1031                 notify = 1;
1032         }
1033         if (new == old)
1034                 goto out;
1035         if (new & NUD_CONNECTED)
1036                 neigh_connect(neigh);
1037         else
1038                 neigh_suspect(neigh);
1039         if (!(old & NUD_VALID)) {
1040                 struct sk_buff *skb;
1041
1042                 /* Again: avoid dead loop if something went wrong */
1043
1044                 while (neigh->nud_state & NUD_VALID &&
1045                        (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
1046                         struct neighbour *n1 = neigh;
1047                         write_unlock_bh(&neigh->lock);
1048                         /* On shaper/eql skb->dst->neighbour != neigh :( */
1049                         if (skb->dst && skb->dst->neighbour)
1050                                 n1 = skb->dst->neighbour;
1051                         n1->output(skb);
1052                         write_lock_bh(&neigh->lock);
1053                 }
1054                 skb_queue_purge(&neigh->arp_queue);
1055         }
1056 out:
1057         if (update_isrouter) {
1058                 neigh->flags = (flags & NEIGH_UPDATE_F_ISROUTER) ?
1059                         (neigh->flags | NTF_ROUTER) :
1060                         (neigh->flags & ~NTF_ROUTER);
1061         }
1062         write_unlock_bh(&neigh->lock);
1063
1064         if (notify)
1065                 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
1066 #ifdef CONFIG_ARPD
1067         if (notify && neigh->parms->app_probes)
1068                 neigh_app_notify(neigh);
1069 #endif
1070         return err;
1071 }
1072
1073 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
1074                                  u8 *lladdr, void *saddr,
1075                                  struct net_device *dev)
1076 {
1077         struct neighbour *neigh = __neigh_lookup(tbl, saddr, dev,
1078                                                  lladdr || !dev->addr_len);
1079         if (neigh)
1080                 neigh_update(neigh, lladdr, NUD_STALE,
1081                              NEIGH_UPDATE_F_OVERRIDE);
1082         return neigh;
1083 }
1084
1085 static void neigh_hh_init(struct neighbour *n, struct dst_entry *dst,
1086                           __be16 protocol)
1087 {
1088         struct hh_cache *hh;
1089         struct net_device *dev = dst->dev;
1090
1091         for (hh = n->hh; hh; hh = hh->hh_next)
1092                 if (hh->hh_type == protocol)
1093                         break;
1094
1095         if (!hh && (hh = kzalloc(sizeof(*hh), GFP_ATOMIC)) != NULL) {
1096                 seqlock_init(&hh->hh_lock);
1097                 hh->hh_type = protocol;
1098                 atomic_set(&hh->hh_refcnt, 0);
1099                 hh->hh_next = NULL;
1100                 if (dev->hard_header_cache(n, hh)) {
1101                         kfree(hh);
1102                         hh = NULL;
1103                 } else {
1104                         atomic_inc(&hh->hh_refcnt);
1105                         hh->hh_next = n->hh;
1106                         n->hh       = hh;
1107                         if (n->nud_state & NUD_CONNECTED)
1108                                 hh->hh_output = n->ops->hh_output;
1109                         else
1110                                 hh->hh_output = n->ops->output;
1111                 }
1112         }
1113         if (hh) {
1114                 atomic_inc(&hh->hh_refcnt);
1115                 dst->hh = hh;
1116         }
1117 }
1118
1119 /* This function can be used in contexts, where only old dev_queue_xmit
1120    worked, f.e. if you want to override normal output path (eql, shaper),
1121    but resolution is not made yet.
1122  */
1123
1124 int neigh_compat_output(struct sk_buff *skb)
1125 {
1126         struct net_device *dev = skb->dev;
1127
1128         __skb_pull(skb, skb->nh.raw - skb->data);
1129
1130         if (dev->hard_header &&
1131             dev->hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
1132                              skb->len) < 0 &&
1133             dev->rebuild_header(skb))
1134                 return 0;
1135
1136         return dev_queue_xmit(skb);
1137 }
1138
1139 /* Slow and careful. */
1140
1141 int neigh_resolve_output(struct sk_buff *skb)
1142 {
1143         struct dst_entry *dst = skb->dst;
1144         struct neighbour *neigh;
1145         int rc = 0;
1146
1147         if (!dst || !(neigh = dst->neighbour))
1148                 goto discard;
1149
1150         __skb_pull(skb, skb->nh.raw - skb->data);
1151
1152         if (!neigh_event_send(neigh, skb)) {
1153                 int err;
1154                 struct net_device *dev = neigh->dev;
1155                 if (dev->hard_header_cache && !dst->hh) {
1156                         write_lock_bh(&neigh->lock);
1157                         if (!dst->hh)
1158                                 neigh_hh_init(neigh, dst, dst->ops->protocol);
1159                         err = dev->hard_header(skb, dev, ntohs(skb->protocol),
1160                                                neigh->ha, NULL, skb->len);
1161                         write_unlock_bh(&neigh->lock);
1162                 } else {
1163                         read_lock_bh(&neigh->lock);
1164                         err = dev->hard_header(skb, dev, ntohs(skb->protocol),
1165                                                neigh->ha, NULL, skb->len);
1166                         read_unlock_bh(&neigh->lock);
1167                 }
1168                 if (err >= 0)
1169                         rc = neigh->ops->queue_xmit(skb);
1170                 else
1171                         goto out_kfree_skb;
1172         }
1173 out:
1174         return rc;
1175 discard:
1176         NEIGH_PRINTK1("neigh_resolve_output: dst=%p neigh=%p\n",
1177                       dst, dst ? dst->neighbour : NULL);
1178 out_kfree_skb:
1179         rc = -EINVAL;
1180         kfree_skb(skb);
1181         goto out;
1182 }
1183
1184 /* As fast as possible without hh cache */
1185
1186 int neigh_connected_output(struct sk_buff *skb)
1187 {
1188         int err;
1189         struct dst_entry *dst = skb->dst;
1190         struct neighbour *neigh = dst->neighbour;
1191         struct net_device *dev = neigh->dev;
1192
1193         __skb_pull(skb, skb->nh.raw - skb->data);
1194
1195         read_lock_bh(&neigh->lock);
1196         err = dev->hard_header(skb, dev, ntohs(skb->protocol),
1197                                neigh->ha, NULL, skb->len);
1198         read_unlock_bh(&neigh->lock);
1199         if (err >= 0)
1200                 err = neigh->ops->queue_xmit(skb);
1201         else {
1202                 err = -EINVAL;
1203                 kfree_skb(skb);
1204         }
1205         return err;
1206 }
1207
1208 static void neigh_proxy_process(unsigned long arg)
1209 {
1210         struct neigh_table *tbl = (struct neigh_table *)arg;
1211         long sched_next = 0;
1212         unsigned long now = jiffies;
1213         struct sk_buff *skb;
1214
1215         spin_lock(&tbl->proxy_queue.lock);
1216
1217         skb = tbl->proxy_queue.next;
1218
1219         while (skb != (struct sk_buff *)&tbl->proxy_queue) {
1220                 struct sk_buff *back = skb;
1221                 long tdif = NEIGH_CB(back)->sched_next - now;
1222
1223                 skb = skb->next;
1224                 if (tdif <= 0) {
1225                         struct net_device *dev = back->dev;
1226                         __skb_unlink(back, &tbl->proxy_queue);
1227                         if (tbl->proxy_redo && netif_running(dev))
1228                                 tbl->proxy_redo(back);
1229                         else
1230                                 kfree_skb(back);
1231
1232                         dev_put(dev);
1233                 } else if (!sched_next || tdif < sched_next)
1234                         sched_next = tdif;
1235         }
1236         del_timer(&tbl->proxy_timer);
1237         if (sched_next)
1238                 mod_timer(&tbl->proxy_timer, jiffies + sched_next);
1239         spin_unlock(&tbl->proxy_queue.lock);
1240 }
1241
1242 void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
1243                     struct sk_buff *skb)
1244 {
1245         unsigned long now = jiffies;
1246         unsigned long sched_next = now + (net_random() % p->proxy_delay);
1247
1248         if (tbl->proxy_queue.qlen > p->proxy_qlen) {
1249                 kfree_skb(skb);
1250                 return;
1251         }
1252
1253         NEIGH_CB(skb)->sched_next = sched_next;
1254         NEIGH_CB(skb)->flags |= LOCALLY_ENQUEUED;
1255
1256         spin_lock(&tbl->proxy_queue.lock);
1257         if (del_timer(&tbl->proxy_timer)) {
1258                 if (time_before(tbl->proxy_timer.expires, sched_next))
1259                         sched_next = tbl->proxy_timer.expires;
1260         }
1261         dst_release(skb->dst);
1262         skb->dst = NULL;
1263         dev_hold(skb->dev);
1264         __skb_queue_tail(&tbl->proxy_queue, skb);
1265         mod_timer(&tbl->proxy_timer, sched_next);
1266         spin_unlock(&tbl->proxy_queue.lock);
1267 }
1268
1269
1270 struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
1271                                       struct neigh_table *tbl)
1272 {
1273         struct neigh_parms *p = kmemdup(&tbl->parms, sizeof(*p), GFP_KERNEL);
1274
1275         if (p) {
1276                 p->tbl            = tbl;
1277                 atomic_set(&p->refcnt, 1);
1278                 INIT_RCU_HEAD(&p->rcu_head);
1279                 p->reachable_time =
1280                                 neigh_rand_reach_time(p->base_reachable_time);
1281                 if (dev) {
1282                         if (dev->neigh_setup && dev->neigh_setup(dev, p)) {
1283                                 kfree(p);
1284                                 return NULL;
1285                         }
1286
1287                         dev_hold(dev);
1288                         p->dev = dev;
1289                 }
1290                 p->sysctl_table = NULL;
1291                 write_lock_bh(&tbl->lock);
1292                 p->next         = tbl->parms.next;
1293                 tbl->parms.next = p;
1294                 write_unlock_bh(&tbl->lock);
1295         }
1296         return p;
1297 }
1298
1299 static void neigh_rcu_free_parms(struct rcu_head *head)
1300 {
1301         struct neigh_parms *parms =
1302                 container_of(head, struct neigh_parms, rcu_head);
1303
1304         neigh_parms_put(parms);
1305 }
1306
1307 void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
1308 {
1309         struct neigh_parms **p;
1310
1311         if (!parms || parms == &tbl->parms)
1312                 return;
1313         write_lock_bh(&tbl->lock);
1314         for (p = &tbl->parms.next; *p; p = &(*p)->next) {
1315                 if (*p == parms) {
1316                         *p = parms->next;
1317                         parms->dead = 1;
1318                         write_unlock_bh(&tbl->lock);
1319                         if (parms->dev)
1320                                 dev_put(parms->dev);
1321                         call_rcu(&parms->rcu_head, neigh_rcu_free_parms);
1322                         return;
1323                 }
1324         }
1325         write_unlock_bh(&tbl->lock);
1326         NEIGH_PRINTK1("neigh_parms_release: not found\n");
1327 }
1328
1329 void neigh_parms_destroy(struct neigh_parms *parms)
1330 {
1331         kfree(parms);
1332 }
1333
1334 void neigh_table_init_no_netlink(struct neigh_table *tbl)
1335 {
1336         unsigned long now = jiffies;
1337         unsigned long phsize;
1338
1339         atomic_set(&tbl->parms.refcnt, 1);
1340         INIT_RCU_HEAD(&tbl->parms.rcu_head);
1341         tbl->parms.reachable_time =
1342                           neigh_rand_reach_time(tbl->parms.base_reachable_time);
1343
1344         if (!tbl->kmem_cachep)
1345                 tbl->kmem_cachep =
1346                         kmem_cache_create(tbl->id, tbl->entry_size, 0,
1347                                           SLAB_HWCACHE_ALIGN|SLAB_PANIC,
1348                                           NULL, NULL);
1349         tbl->stats = alloc_percpu(struct neigh_statistics);
1350         if (!tbl->stats)
1351                 panic("cannot create neighbour cache statistics");
1352
1353 #ifdef CONFIG_PROC_FS
1354         tbl->pde = create_proc_entry(tbl->id, 0, proc_net_stat);
1355         if (!tbl->pde)
1356                 panic("cannot create neighbour proc dir entry");
1357         tbl->pde->proc_fops = &neigh_stat_seq_fops;
1358         tbl->pde->data = tbl;
1359 #endif
1360
1361         tbl->hash_mask = 1;
1362         tbl->hash_buckets = neigh_hash_alloc(tbl->hash_mask + 1);
1363
1364         phsize = (PNEIGH_HASHMASK + 1) * sizeof(struct pneigh_entry *);
1365         tbl->phash_buckets = kzalloc(phsize, GFP_KERNEL);
1366
1367         if (!tbl->hash_buckets || !tbl->phash_buckets)
1368                 panic("cannot allocate neighbour cache hashes");
1369
1370         get_random_bytes(&tbl->hash_rnd, sizeof(tbl->hash_rnd));
1371
1372         rwlock_init(&tbl->lock);
1373         init_timer(&tbl->gc_timer);
1374         tbl->gc_timer.data     = (unsigned long)tbl;
1375         tbl->gc_timer.function = neigh_periodic_timer;
1376         tbl->gc_timer.expires  = now + 1;
1377         add_timer(&tbl->gc_timer);
1378
1379         init_timer(&tbl->proxy_timer);
1380         tbl->proxy_timer.data     = (unsigned long)tbl;
1381         tbl->proxy_timer.function = neigh_proxy_process;
1382         skb_queue_head_init(&tbl->proxy_queue);
1383
1384         tbl->last_flush = now;
1385         tbl->last_rand  = now + tbl->parms.reachable_time * 20;
1386 }
1387
1388 void neigh_table_init(struct neigh_table *tbl)
1389 {
1390         struct neigh_table *tmp;
1391
1392         neigh_table_init_no_netlink(tbl);
1393         write_lock(&neigh_tbl_lock);
1394         for (tmp = neigh_tables; tmp; tmp = tmp->next) {
1395                 if (tmp->family == tbl->family)
1396                         break;
1397         }
1398         tbl->next       = neigh_tables;
1399         neigh_tables    = tbl;
1400         write_unlock(&neigh_tbl_lock);
1401
1402         if (unlikely(tmp)) {
1403                 printk(KERN_ERR "NEIGH: Registering multiple tables for "
1404                        "family %d\n", tbl->family);
1405                 dump_stack();
1406         }
1407 }
1408
1409 int neigh_table_clear(struct neigh_table *tbl)
1410 {
1411         struct neigh_table **tp;
1412
1413         /* It is not clean... Fix it to unload IPv6 module safely */
1414         del_timer_sync(&tbl->gc_timer);
1415         del_timer_sync(&tbl->proxy_timer);
1416         pneigh_queue_purge(&tbl->proxy_queue);
1417         neigh_ifdown(tbl, NULL);
1418         if (atomic_read(&tbl->entries))
1419                 printk(KERN_CRIT "neighbour leakage\n");
1420         write_lock(&neigh_tbl_lock);
1421         for (tp = &neigh_tables; *tp; tp = &(*tp)->next) {
1422                 if (*tp == tbl) {
1423                         *tp = tbl->next;
1424                         break;
1425                 }
1426         }
1427         write_unlock(&neigh_tbl_lock);
1428
1429         neigh_hash_free(tbl->hash_buckets, tbl->hash_mask + 1);
1430         tbl->hash_buckets = NULL;
1431
1432         kfree(tbl->phash_buckets);
1433         tbl->phash_buckets = NULL;
1434
1435         free_percpu(tbl->stats);
1436         tbl->stats = NULL;
1437
1438         return 0;
1439 }
1440
1441 int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
1442 {
1443         struct ndmsg *ndm;
1444         struct nlattr *dst_attr;
1445         struct neigh_table *tbl;
1446         struct net_device *dev = NULL;
1447         int err = -EINVAL;
1448
1449         if (nlmsg_len(nlh) < sizeof(*ndm))
1450                 goto out;
1451
1452         dst_attr = nlmsg_find_attr(nlh, sizeof(*ndm), NDA_DST);
1453         if (dst_attr == NULL)
1454                 goto out;
1455
1456         ndm = nlmsg_data(nlh);
1457         if (ndm->ndm_ifindex) {
1458                 dev = dev_get_by_index(ndm->ndm_ifindex);
1459                 if (dev == NULL) {
1460                         err = -ENODEV;
1461                         goto out;
1462                 }
1463         }
1464
1465         read_lock(&neigh_tbl_lock);
1466         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1467                 struct neighbour *neigh;
1468
1469                 if (tbl->family != ndm->ndm_family)
1470                         continue;
1471                 read_unlock(&neigh_tbl_lock);
1472
1473                 if (nla_len(dst_attr) < tbl->key_len)
1474                         goto out_dev_put;
1475
1476                 if (ndm->ndm_flags & NTF_PROXY) {
1477                         err = pneigh_delete(tbl, nla_data(dst_attr), dev);
1478                         goto out_dev_put;
1479                 }
1480
1481                 if (dev == NULL)
1482                         goto out_dev_put;
1483
1484                 neigh = neigh_lookup(tbl, nla_data(dst_attr), dev);
1485                 if (neigh == NULL) {
1486                         err = -ENOENT;
1487                         goto out_dev_put;
1488                 }
1489
1490                 err = neigh_update(neigh, NULL, NUD_FAILED,
1491                                    NEIGH_UPDATE_F_OVERRIDE |
1492                                    NEIGH_UPDATE_F_ADMIN);
1493                 neigh_release(neigh);
1494                 goto out_dev_put;
1495         }
1496         read_unlock(&neigh_tbl_lock);
1497         err = -EAFNOSUPPORT;
1498
1499 out_dev_put:
1500         if (dev)
1501                 dev_put(dev);
1502 out:
1503         return err;
1504 }
1505
1506 int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
1507 {
1508         struct ndmsg *ndm;
1509         struct nlattr *tb[NDA_MAX+1];
1510         struct neigh_table *tbl;
1511         struct net_device *dev = NULL;
1512         int err;
1513
1514         err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
1515         if (err < 0)
1516                 goto out;
1517
1518         err = -EINVAL;
1519         if (tb[NDA_DST] == NULL)
1520                 goto out;
1521
1522         ndm = nlmsg_data(nlh);
1523         if (ndm->ndm_ifindex) {
1524                 dev = dev_get_by_index(ndm->ndm_ifindex);
1525                 if (dev == NULL) {
1526                         err = -ENODEV;
1527                         goto out;
1528                 }
1529
1530                 if (tb[NDA_LLADDR] && nla_len(tb[NDA_LLADDR]) < dev->addr_len)
1531                         goto out_dev_put;
1532         }
1533
1534         read_lock(&neigh_tbl_lock);
1535         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1536                 int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE;
1537                 struct neighbour *neigh;
1538                 void *dst, *lladdr;
1539
1540                 if (tbl->family != ndm->ndm_family)
1541                         continue;
1542                 read_unlock(&neigh_tbl_lock);
1543
1544                 if (nla_len(tb[NDA_DST]) < tbl->key_len)
1545                         goto out_dev_put;
1546                 dst = nla_data(tb[NDA_DST]);
1547                 lladdr = tb[NDA_LLADDR] ? nla_data(tb[NDA_LLADDR]) : NULL;
1548
1549                 if (ndm->ndm_flags & NTF_PROXY) {
1550                         struct pneigh_entry *pn;
1551
1552                         err = -ENOBUFS;
1553                         pn = pneigh_lookup(tbl, dst, dev, 1);
1554                         if (pn) {
1555                                 pn->flags = ndm->ndm_flags;
1556                                 err = 0;
1557                         }
1558                         goto out_dev_put;
1559                 }
1560
1561                 if (dev == NULL)
1562                         goto out_dev_put;
1563
1564                 neigh = neigh_lookup(tbl, dst, dev);
1565                 if (neigh == NULL) {
1566                         if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
1567                                 err = -ENOENT;
1568                                 goto out_dev_put;
1569                         }
1570
1571                         neigh = __neigh_lookup_errno(tbl, dst, dev);
1572                         if (IS_ERR(neigh)) {
1573                                 err = PTR_ERR(neigh);
1574                                 goto out_dev_put;
1575                         }
1576                 } else {
1577                         if (nlh->nlmsg_flags & NLM_F_EXCL) {
1578                                 err = -EEXIST;
1579                                 neigh_release(neigh);
1580                                 goto out_dev_put;
1581                         }
1582
1583                         if (!(nlh->nlmsg_flags & NLM_F_REPLACE))
1584                                 flags &= ~NEIGH_UPDATE_F_OVERRIDE;
1585                 }
1586
1587                 err = neigh_update(neigh, lladdr, ndm->ndm_state, flags);
1588                 neigh_release(neigh);
1589                 goto out_dev_put;
1590         }
1591
1592         read_unlock(&neigh_tbl_lock);
1593         err = -EAFNOSUPPORT;
1594
1595 out_dev_put:
1596         if (dev)
1597                 dev_put(dev);
1598 out:
1599         return err;
1600 }
1601
1602 static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms)
1603 {
1604         struct nlattr *nest;
1605
1606         nest = nla_nest_start(skb, NDTA_PARMS);
1607         if (nest == NULL)
1608                 return -ENOBUFS;
1609
1610         if (parms->dev)
1611                 NLA_PUT_U32(skb, NDTPA_IFINDEX, parms->dev->ifindex);
1612
1613         NLA_PUT_U32(skb, NDTPA_REFCNT, atomic_read(&parms->refcnt));
1614         NLA_PUT_U32(skb, NDTPA_QUEUE_LEN, parms->queue_len);
1615         NLA_PUT_U32(skb, NDTPA_PROXY_QLEN, parms->proxy_qlen);
1616         NLA_PUT_U32(skb, NDTPA_APP_PROBES, parms->app_probes);
1617         NLA_PUT_U32(skb, NDTPA_UCAST_PROBES, parms->ucast_probes);
1618         NLA_PUT_U32(skb, NDTPA_MCAST_PROBES, parms->mcast_probes);
1619         NLA_PUT_MSECS(skb, NDTPA_REACHABLE_TIME, parms->reachable_time);
1620         NLA_PUT_MSECS(skb, NDTPA_BASE_REACHABLE_TIME,
1621                       parms->base_reachable_time);
1622         NLA_PUT_MSECS(skb, NDTPA_GC_STALETIME, parms->gc_staletime);
1623         NLA_PUT_MSECS(skb, NDTPA_DELAY_PROBE_TIME, parms->delay_probe_time);
1624         NLA_PUT_MSECS(skb, NDTPA_RETRANS_TIME, parms->retrans_time);
1625         NLA_PUT_MSECS(skb, NDTPA_ANYCAST_DELAY, parms->anycast_delay);
1626         NLA_PUT_MSECS(skb, NDTPA_PROXY_DELAY, parms->proxy_delay);
1627         NLA_PUT_MSECS(skb, NDTPA_LOCKTIME, parms->locktime);
1628
1629         return nla_nest_end(skb, nest);
1630
1631 nla_put_failure:
1632         return nla_nest_cancel(skb, nest);
1633 }
1634
1635 static int neightbl_fill_info(struct sk_buff *skb, struct neigh_table *tbl,
1636                               u32 pid, u32 seq, int type, int flags)
1637 {
1638         struct nlmsghdr *nlh;
1639         struct ndtmsg *ndtmsg;
1640
1641         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
1642         if (nlh == NULL)
1643                 return -EMSGSIZE;
1644
1645         ndtmsg = nlmsg_data(nlh);
1646
1647         read_lock_bh(&tbl->lock);
1648         ndtmsg->ndtm_family = tbl->family;
1649         ndtmsg->ndtm_pad1   = 0;
1650         ndtmsg->ndtm_pad2   = 0;
1651
1652         NLA_PUT_STRING(skb, NDTA_NAME, tbl->id);
1653         NLA_PUT_MSECS(skb, NDTA_GC_INTERVAL, tbl->gc_interval);
1654         NLA_PUT_U32(skb, NDTA_THRESH1, tbl->gc_thresh1);
1655         NLA_PUT_U32(skb, NDTA_THRESH2, tbl->gc_thresh2);
1656         NLA_PUT_U32(skb, NDTA_THRESH3, tbl->gc_thresh3);
1657
1658         {
1659                 unsigned long now = jiffies;
1660                 unsigned int flush_delta = now - tbl->last_flush;
1661                 unsigned int rand_delta = now - tbl->last_rand;
1662
1663                 struct ndt_config ndc = {
1664                         .ndtc_key_len           = tbl->key_len,
1665                         .ndtc_entry_size        = tbl->entry_size,
1666                         .ndtc_entries           = atomic_read(&tbl->entries),
1667                         .ndtc_last_flush        = jiffies_to_msecs(flush_delta),
1668                         .ndtc_last_rand         = jiffies_to_msecs(rand_delta),
1669                         .ndtc_hash_rnd          = tbl->hash_rnd,
1670                         .ndtc_hash_mask         = tbl->hash_mask,
1671                         .ndtc_hash_chain_gc     = tbl->hash_chain_gc,
1672                         .ndtc_proxy_qlen        = tbl->proxy_queue.qlen,
1673                 };
1674
1675                 NLA_PUT(skb, NDTA_CONFIG, sizeof(ndc), &ndc);
1676         }
1677
1678         {
1679                 int cpu;
1680                 struct ndt_stats ndst;
1681
1682                 memset(&ndst, 0, sizeof(ndst));
1683
1684                 for_each_possible_cpu(cpu) {
1685                         struct neigh_statistics *st;
1686
1687                         st = per_cpu_ptr(tbl->stats, cpu);
1688                         ndst.ndts_allocs                += st->allocs;
1689                         ndst.ndts_destroys              += st->destroys;
1690                         ndst.ndts_hash_grows            += st->hash_grows;
1691                         ndst.ndts_res_failed            += st->res_failed;
1692                         ndst.ndts_lookups               += st->lookups;
1693                         ndst.ndts_hits                  += st->hits;
1694                         ndst.ndts_rcv_probes_mcast      += st->rcv_probes_mcast;
1695                         ndst.ndts_rcv_probes_ucast      += st->rcv_probes_ucast;
1696                         ndst.ndts_periodic_gc_runs      += st->periodic_gc_runs;
1697                         ndst.ndts_forced_gc_runs        += st->forced_gc_runs;
1698                 }
1699
1700                 NLA_PUT(skb, NDTA_STATS, sizeof(ndst), &ndst);
1701         }
1702
1703         BUG_ON(tbl->parms.dev);
1704         if (neightbl_fill_parms(skb, &tbl->parms) < 0)
1705                 goto nla_put_failure;
1706
1707         read_unlock_bh(&tbl->lock);
1708         return nlmsg_end(skb, nlh);
1709
1710 nla_put_failure:
1711         read_unlock_bh(&tbl->lock);
1712         nlmsg_cancel(skb, nlh);
1713         return -EMSGSIZE;
1714 }
1715
1716 static int neightbl_fill_param_info(struct sk_buff *skb,
1717                                     struct neigh_table *tbl,
1718                                     struct neigh_parms *parms,
1719                                     u32 pid, u32 seq, int type,
1720                                     unsigned int flags)
1721 {
1722         struct ndtmsg *ndtmsg;
1723         struct nlmsghdr *nlh;
1724
1725         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
1726         if (nlh == NULL)
1727                 return -EMSGSIZE;
1728
1729         ndtmsg = nlmsg_data(nlh);
1730
1731         read_lock_bh(&tbl->lock);
1732         ndtmsg->ndtm_family = tbl->family;
1733         ndtmsg->ndtm_pad1   = 0;
1734         ndtmsg->ndtm_pad2   = 0;
1735
1736         if (nla_put_string(skb, NDTA_NAME, tbl->id) < 0 ||
1737             neightbl_fill_parms(skb, parms) < 0)
1738                 goto errout;
1739
1740         read_unlock_bh(&tbl->lock);
1741         return nlmsg_end(skb, nlh);
1742 errout:
1743         read_unlock_bh(&tbl->lock);
1744         nlmsg_cancel(skb, nlh);
1745         return -EMSGSIZE;
1746 }
1747
1748 static inline struct neigh_parms *lookup_neigh_params(struct neigh_table *tbl,
1749                                                       int ifindex)
1750 {
1751         struct neigh_parms *p;
1752
1753         for (p = &tbl->parms; p; p = p->next)
1754                 if ((p->dev && p->dev->ifindex == ifindex) ||
1755                     (!p->dev && !ifindex))
1756                         return p;
1757
1758         return NULL;
1759 }
1760
1761 static struct nla_policy nl_neightbl_policy[NDTA_MAX+1] __read_mostly = {
1762         [NDTA_NAME]             = { .type = NLA_STRING },
1763         [NDTA_THRESH1]          = { .type = NLA_U32 },
1764         [NDTA_THRESH2]          = { .type = NLA_U32 },
1765         [NDTA_THRESH3]          = { .type = NLA_U32 },
1766         [NDTA_GC_INTERVAL]      = { .type = NLA_U64 },
1767         [NDTA_PARMS]            = { .type = NLA_NESTED },
1768 };
1769
1770 static struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] __read_mostly = {
1771         [NDTPA_IFINDEX]                 = { .type = NLA_U32 },
1772         [NDTPA_QUEUE_LEN]               = { .type = NLA_U32 },
1773         [NDTPA_PROXY_QLEN]              = { .type = NLA_U32 },
1774         [NDTPA_APP_PROBES]              = { .type = NLA_U32 },
1775         [NDTPA_UCAST_PROBES]            = { .type = NLA_U32 },
1776         [NDTPA_MCAST_PROBES]            = { .type = NLA_U32 },
1777         [NDTPA_BASE_REACHABLE_TIME]     = { .type = NLA_U64 },
1778         [NDTPA_GC_STALETIME]            = { .type = NLA_U64 },
1779         [NDTPA_DELAY_PROBE_TIME]        = { .type = NLA_U64 },
1780         [NDTPA_RETRANS_TIME]            = { .type = NLA_U64 },
1781         [NDTPA_ANYCAST_DELAY]           = { .type = NLA_U64 },
1782         [NDTPA_PROXY_DELAY]             = { .type = NLA_U64 },
1783         [NDTPA_LOCKTIME]                = { .type = NLA_U64 },
1784 };
1785
1786 int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
1787 {
1788         struct neigh_table *tbl;
1789         struct ndtmsg *ndtmsg;
1790         struct nlattr *tb[NDTA_MAX+1];
1791         int err;
1792
1793         err = nlmsg_parse(nlh, sizeof(*ndtmsg), tb, NDTA_MAX,
1794                           nl_neightbl_policy);
1795         if (err < 0)
1796                 goto errout;
1797
1798         if (tb[NDTA_NAME] == NULL) {
1799                 err = -EINVAL;
1800                 goto errout;
1801         }
1802
1803         ndtmsg = nlmsg_data(nlh);
1804         read_lock(&neigh_tbl_lock);
1805         for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1806                 if (ndtmsg->ndtm_family && tbl->family != ndtmsg->ndtm_family)
1807                         continue;
1808
1809                 if (nla_strcmp(tb[NDTA_NAME], tbl->id) == 0)
1810                         break;
1811         }
1812
1813         if (tbl == NULL) {
1814                 err = -ENOENT;
1815                 goto errout_locked;
1816         }
1817
1818         /*
1819          * We acquire tbl->lock to be nice to the periodic timers and
1820          * make sure they always see a consistent set of values.
1821          */
1822         write_lock_bh(&tbl->lock);
1823
1824         if (tb[NDTA_PARMS]) {
1825                 struct nlattr *tbp[NDTPA_MAX+1];
1826                 struct neigh_parms *p;
1827                 int i, ifindex = 0;
1828
1829                 err = nla_parse_nested(tbp, NDTPA_MAX, tb[NDTA_PARMS],
1830                                        nl_ntbl_parm_policy);
1831                 if (err < 0)
1832                         goto errout_tbl_lock;
1833
1834                 if (tbp[NDTPA_IFINDEX])
1835                         ifindex = nla_get_u32(tbp[NDTPA_IFINDEX]);
1836
1837                 p = lookup_neigh_params(tbl, ifindex);
1838                 if (p == NULL) {
1839                         err = -ENOENT;
1840                         goto errout_tbl_lock;
1841                 }
1842
1843                 for (i = 1; i <= NDTPA_MAX; i++) {
1844                         if (tbp[i] == NULL)
1845                                 continue;
1846
1847                         switch (i) {
1848                         case NDTPA_QUEUE_LEN:
1849                                 p->queue_len = nla_get_u32(tbp[i]);
1850                                 break;
1851                         case NDTPA_PROXY_QLEN:
1852                                 p->proxy_qlen = nla_get_u32(tbp[i]);
1853                                 break;
1854                         case NDTPA_APP_PROBES:
1855                                 p->app_probes = nla_get_u32(tbp[i]);
1856                                 break;
1857                         case NDTPA_UCAST_PROBES:
1858                                 p->ucast_probes = nla_get_u32(tbp[i]);
1859                                 break;
1860                         case NDTPA_MCAST_PROBES:
1861                                 p->mcast_probes = nla_get_u32(tbp[i]);
1862                                 break;
1863                         case NDTPA_BASE_REACHABLE_TIME:
1864                                 p->base_reachable_time = nla_get_msecs(tbp[i]);
1865                                 break;
1866                         case NDTPA_GC_STALETIME:
1867                                 p->gc_staletime = nla_get_msecs(tbp[i]);
1868                                 break;
1869                         case NDTPA_DELAY_PROBE_TIME:
1870                                 p->delay_probe_time = nla_get_msecs(tbp[i]);
1871                                 break;
1872                         case NDTPA_RETRANS_TIME:
1873                                 p->retrans_time = nla_get_msecs(tbp[i]);
1874                                 break;
1875                         case NDTPA_ANYCAST_DELAY:
1876                                 p->anycast_delay = nla_get_msecs(tbp[i]);
1877                                 break;
1878                         case NDTPA_PROXY_DELAY:
1879                                 p->proxy_delay = nla_get_msecs(tbp[i]);
1880                                 break;
1881                         case NDTPA_LOCKTIME:
1882                                 p->locktime = nla_get_msecs(tbp[i]);
1883                                 break;
1884                         }
1885                 }
1886         }
1887
1888         if (tb[NDTA_THRESH1])
1889                 tbl->gc_thresh1 = nla_get_u32(tb[NDTA_THRESH1]);
1890
1891         if (tb[NDTA_THRESH2])
1892                 tbl->gc_thresh2 = nla_get_u32(tb[NDTA_THRESH2]);
1893
1894         if (tb[NDTA_THRESH3])
1895                 tbl->gc_thresh3 = nla_get_u32(tb[NDTA_THRESH3]);
1896
1897         if (tb[NDTA_GC_INTERVAL])
1898                 tbl->gc_interval = nla_get_msecs(tb[NDTA_GC_INTERVAL]);
1899
1900         err = 0;
1901
1902 errout_tbl_lock:
1903         write_unlock_bh(&tbl->lock);
1904 errout_locked:
1905         read_unlock(&neigh_tbl_lock);
1906 errout:
1907         return err;
1908 }
1909
1910 int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
1911 {
1912         int family, tidx, nidx = 0;
1913         int tbl_skip = cb->args[0];
1914         int neigh_skip = cb->args[1];
1915         struct neigh_table *tbl;
1916
1917         family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;
1918
1919         read_lock(&neigh_tbl_lock);
1920         for (tbl = neigh_tables, tidx = 0; tbl; tbl = tbl->next, tidx++) {
1921                 struct neigh_parms *p;
1922
1923                 if (tidx < tbl_skip || (family && tbl->family != family))
1924                         continue;
1925
1926                 if (neightbl_fill_info(skb, tbl, NETLINK_CB(cb->skb).pid,
1927                                        cb->nlh->nlmsg_seq, RTM_NEWNEIGHTBL,
1928                                        NLM_F_MULTI) <= 0)
1929                         break;
1930
1931                 for (nidx = 0, p = tbl->parms.next; p; p = p->next, nidx++) {
1932                         if (nidx < neigh_skip)
1933                                 continue;
1934
1935                         if (neightbl_fill_param_info(skb, tbl, p,
1936                                                      NETLINK_CB(cb->skb).pid,
1937                                                      cb->nlh->nlmsg_seq,
1938                                                      RTM_NEWNEIGHTBL,
1939                                                      NLM_F_MULTI) <= 0)
1940                                 goto out;
1941                 }
1942
1943                 neigh_skip = 0;
1944         }
1945 out:
1946         read_unlock(&neigh_tbl_lock);
1947         cb->args[0] = tidx;
1948         cb->args[1] = nidx;
1949
1950         return skb->len;
1951 }
1952
1953 static int neigh_fill_info(struct sk_buff *skb, struct neighbour *neigh,
1954                            u32 pid, u32 seq, int type, unsigned int flags)
1955 {
1956         unsigned long now = jiffies;
1957         struct nda_cacheinfo ci;
1958         struct nlmsghdr *nlh;
1959         struct ndmsg *ndm;
1960
1961         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
1962         if (nlh == NULL)
1963                 return -EMSGSIZE;
1964
1965         ndm = nlmsg_data(nlh);
1966         ndm->ndm_family  = neigh->ops->family;
1967         ndm->ndm_pad1    = 0;
1968         ndm->ndm_pad2    = 0;
1969         ndm->ndm_flags   = neigh->flags;
1970         ndm->ndm_type    = neigh->type;
1971         ndm->ndm_ifindex = neigh->dev->ifindex;
1972
1973         NLA_PUT(skb, NDA_DST, neigh->tbl->key_len, neigh->primary_key);
1974
1975         read_lock_bh(&neigh->lock);
1976         ndm->ndm_state   = neigh->nud_state;
1977         if ((neigh->nud_state & NUD_VALID) &&
1978             nla_put(skb, NDA_LLADDR, neigh->dev->addr_len, neigh->ha) < 0) {
1979                 read_unlock_bh(&neigh->lock);
1980                 goto nla_put_failure;
1981         }
1982
1983         ci.ndm_used      = now - neigh->used;
1984         ci.ndm_confirmed = now - neigh->confirmed;
1985         ci.ndm_updated   = now - neigh->updated;
1986         ci.ndm_refcnt    = atomic_read(&neigh->refcnt) - 1;
1987         read_unlock_bh(&neigh->lock);
1988
1989         NLA_PUT_U32(skb, NDA_PROBES, atomic_read(&neigh->probes));
1990         NLA_PUT(skb, NDA_CACHEINFO, sizeof(ci), &ci);
1991
1992         return nlmsg_end(skb, nlh);
1993
1994 nla_put_failure:
1995         nlmsg_cancel(skb, nlh);
1996         return -EMSGSIZE;
1997 }
1998
1999
2000 static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
2001                             struct netlink_callback *cb)
2002 {
2003         struct neighbour *n;
2004         int rc, h, s_h = cb->args[1];
2005         int idx, s_idx = idx = cb->args[2];
2006
2007         read_lock_bh(&tbl->lock);
2008         for (h = 0; h <= tbl->hash_mask; h++) {
2009                 if (h < s_h)
2010                         continue;
2011                 if (h > s_h)
2012                         s_idx = 0;
2013                 for (n = tbl->hash_buckets[h], idx = 0; n; n = n->next, idx++) {
2014                         if (idx < s_idx)
2015                                 continue;
2016                         if (neigh_fill_info(skb, n, NETLINK_CB(cb->skb).pid,
2017                                             cb->nlh->nlmsg_seq,
2018                                             RTM_NEWNEIGH,
2019                                             NLM_F_MULTI) <= 0) {
2020                                 read_unlock_bh(&tbl->lock);
2021                                 rc = -1;
2022                                 goto out;
2023                         }
2024                 }
2025         }
2026         read_unlock_bh(&tbl->lock);
2027         rc = skb->len;
2028 out:
2029         cb->args[1] = h;
2030         cb->args[2] = idx;
2031         return rc;
2032 }
2033
2034 int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2035 {
2036         struct neigh_table *tbl;
2037         int t, family, s_t;
2038
2039         read_lock(&neigh_tbl_lock);
2040         family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;
2041         s_t = cb->args[0];
2042
2043         for (tbl = neigh_tables, t = 0; tbl; tbl = tbl->next, t++) {
2044                 if (t < s_t || (family && tbl->family != family))
2045                         continue;
2046                 if (t > s_t)
2047                         memset(&cb->args[1], 0, sizeof(cb->args) -
2048                                                 sizeof(cb->args[0]));
2049                 if (neigh_dump_table(tbl, skb, cb) < 0)
2050                         break;
2051         }
2052         read_unlock(&neigh_tbl_lock);
2053
2054         cb->args[0] = t;
2055         return skb->len;
2056 }
2057
2058 void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie)
2059 {
2060         int chain;
2061
2062         read_lock_bh(&tbl->lock);
2063         for (chain = 0; chain <= tbl->hash_mask; chain++) {
2064                 struct neighbour *n;
2065
2066                 for (n = tbl->hash_buckets[chain]; n; n = n->next)
2067                         cb(n, cookie);
2068         }
2069         read_unlock_bh(&tbl->lock);
2070 }
2071 EXPORT_SYMBOL(neigh_for_each);
2072
2073 /* The tbl->lock must be held as a writer and BH disabled. */
2074 void __neigh_for_each_release(struct neigh_table *tbl,
2075                               int (*cb)(struct neighbour *))
2076 {
2077         int chain;
2078
2079         for (chain = 0; chain <= tbl->hash_mask; chain++) {
2080                 struct neighbour *n, **np;
2081
2082                 np = &tbl->hash_buckets[chain];
2083                 while ((n = *np) != NULL) {
2084                         int release;
2085
2086                         write_lock(&n->lock);
2087                         release = cb(n);
2088                         if (release) {
2089                                 *np = n->next;
2090                                 n->dead = 1;
2091                         } else
2092                                 np = &n->next;
2093                         write_unlock(&n->lock);
2094                         if (release) {
2095                                 if (n->parms->neigh_cleanup)
2096                                         n->parms->neigh_cleanup(n);
2097                                 neigh_release(n);
2098                         }
2099                 }
2100         }
2101 }
2102 EXPORT_SYMBOL(__neigh_for_each_release);
2103
2104 #ifdef CONFIG_PROC_FS
2105
2106 static struct neighbour *neigh_get_first(struct seq_file *seq)
2107 {
2108         struct neigh_seq_state *state = seq->private;
2109         struct neigh_table *tbl = state->tbl;
2110         struct neighbour *n = NULL;
2111         int bucket = state->bucket;
2112
2113         state->flags &= ~NEIGH_SEQ_IS_PNEIGH;
2114         for (bucket = 0; bucket <= tbl->hash_mask; bucket++) {
2115                 n = tbl->hash_buckets[bucket];
2116
2117                 while (n) {
2118                         if (state->neigh_sub_iter) {
2119                                 loff_t fakep = 0;
2120                                 void *v;
2121
2122                                 v = state->neigh_sub_iter(state, n, &fakep);
2123                                 if (!v)
2124                                         goto next;
2125                         }
2126                         if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
2127                                 break;
2128                         if (n->nud_state & ~NUD_NOARP)
2129                                 break;
2130                 next:
2131                         n = n->next;
2132                 }
2133
2134                 if (n)
2135                         break;
2136         }
2137         state->bucket = bucket;
2138
2139         return n;
2140 }
2141
2142 static struct neighbour *neigh_get_next(struct seq_file *seq,
2143                                         struct neighbour *n,
2144                                         loff_t *pos)
2145 {
2146         struct neigh_seq_state *state = seq->private;
2147         struct neigh_table *tbl = state->tbl;
2148
2149         if (state->neigh_sub_iter) {
2150                 void *v = state->neigh_sub_iter(state, n, pos);
2151                 if (v)
2152                         return n;
2153         }
2154         n = n->next;
2155
2156         while (1) {
2157                 while (n) {
2158                         if (state->neigh_sub_iter) {
2159                                 void *v = state->neigh_sub_iter(state, n, pos);
2160                                 if (v)
2161                                         return n;
2162                                 goto next;
2163                         }
2164                         if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
2165                                 break;
2166
2167                         if (n->nud_state & ~NUD_NOARP)
2168                                 break;
2169                 next:
2170                         n = n->next;
2171                 }
2172
2173                 if (n)
2174                         break;
2175
2176                 if (++state->bucket > tbl->hash_mask)
2177                         break;
2178
2179                 n = tbl->hash_buckets[state->bucket];
2180         }
2181
2182         if (n && pos)
2183                 --(*pos);
2184         return n;
2185 }
2186
2187 static struct neighbour *neigh_get_idx(struct seq_file *seq, loff_t *pos)
2188 {
2189         struct neighbour *n = neigh_get_first(seq);
2190
2191         if (n) {
2192                 while (*pos) {
2193                         n = neigh_get_next(seq, n, pos);
2194                         if (!n)
2195                                 break;
2196                 }
2197         }
2198         return *pos ? NULL : n;
2199 }
2200
2201 static struct pneigh_entry *pneigh_get_first(struct seq_file *seq)
2202 {
2203         struct neigh_seq_state *state = seq->private;
2204         struct neigh_table *tbl = state->tbl;
2205         struct pneigh_entry *pn = NULL;
2206         int bucket = state->bucket;
2207
2208         state->flags |= NEIGH_SEQ_IS_PNEIGH;
2209         for (bucket = 0; bucket <= PNEIGH_HASHMASK; bucket++) {
2210                 pn = tbl->phash_buckets[bucket];
2211                 if (pn)
2212                         break;
2213         }
2214         state->bucket = bucket;
2215
2216         return pn;
2217 }
2218
2219 static struct pneigh_entry *pneigh_get_next(struct seq_file *seq,
2220                                             struct pneigh_entry *pn,
2221                                             loff_t *pos)
2222 {
2223         struct neigh_seq_state *state = seq->private;
2224         struct neigh_table *tbl = state->tbl;
2225
2226         pn = pn->next;
2227         while (!pn) {
2228                 if (++state->bucket > PNEIGH_HASHMASK)
2229                         break;
2230                 pn = tbl->phash_buckets[state->bucket];
2231                 if (pn)
2232                         break;
2233         }
2234
2235         if (pn && pos)
2236                 --(*pos);
2237
2238         return pn;
2239 }
2240
2241 static struct pneigh_entry *pneigh_get_idx(struct seq_file *seq, loff_t *pos)
2242 {
2243         struct pneigh_entry *pn = pneigh_get_first(seq);
2244
2245         if (pn) {
2246                 while (*pos) {
2247                         pn = pneigh_get_next(seq, pn, pos);
2248                         if (!pn)
2249                                 break;
2250                 }
2251         }
2252         return *pos ? NULL : pn;
2253 }
2254
2255 static void *neigh_get_idx_any(struct seq_file *seq, loff_t *pos)
2256 {
2257         struct neigh_seq_state *state = seq->private;
2258         void *rc;
2259
2260         rc = neigh_get_idx(seq, pos);
2261         if (!rc && !(state->flags & NEIGH_SEQ_NEIGH_ONLY))
2262                 rc = pneigh_get_idx(seq, pos);
2263
2264         return rc;
2265 }
2266
2267 void *neigh_seq_start(struct seq_file *seq, loff_t *pos, struct neigh_table *tbl, unsigned int neigh_seq_flags)
2268 {
2269         struct neigh_seq_state *state = seq->private;
2270         loff_t pos_minus_one;
2271
2272         state->tbl = tbl;
2273         state->bucket = 0;
2274         state->flags = (neigh_seq_flags & ~NEIGH_SEQ_IS_PNEIGH);
2275
2276         read_lock_bh(&tbl->lock);
2277
2278         pos_minus_one = *pos - 1;
2279         return *pos ? neigh_get_idx_any(seq, &pos_minus_one) : SEQ_START_TOKEN;
2280 }
2281 EXPORT_SYMBOL(neigh_seq_start);
2282
2283 void *neigh_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2284 {
2285         struct neigh_seq_state *state;
2286         void *rc;
2287
2288         if (v == SEQ_START_TOKEN) {
2289                 rc = neigh_get_idx(seq, pos);
2290                 goto out;
2291         }
2292
2293         state = seq->private;
2294         if (!(state->flags & NEIGH_SEQ_IS_PNEIGH)) {
2295                 rc = neigh_get_next(seq, v, NULL);
2296                 if (rc)
2297                         goto out;
2298                 if (!(state->flags & NEIGH_SEQ_NEIGH_ONLY))
2299                         rc = pneigh_get_first(seq);
2300         } else {
2301                 BUG_ON(state->flags & NEIGH_SEQ_NEIGH_ONLY);
2302                 rc = pneigh_get_next(seq, v, NULL);
2303         }
2304 out:
2305         ++(*pos);
2306         return rc;
2307 }
2308 EXPORT_SYMBOL(neigh_seq_next);
2309
2310 void neigh_seq_stop(struct seq_file *seq, void *v)
2311 {
2312         struct neigh_seq_state *state = seq->private;
2313         struct neigh_table *tbl = state->tbl;
2314
2315         read_unlock_bh(&tbl->lock);
2316 }
2317 EXPORT_SYMBOL(neigh_seq_stop);
2318
2319 /* statistics via seq_file */
2320
2321 static void *neigh_stat_seq_start(struct seq_file *seq, loff_t *pos)
2322 {
2323         struct proc_dir_entry *pde = seq->private;
2324         struct neigh_table *tbl = pde->data;
2325         int cpu;
2326
2327         if (*pos == 0)
2328                 return SEQ_START_TOKEN;
2329
2330         for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
2331                 if (!cpu_possible(cpu))
2332                         continue;
2333                 *pos = cpu+1;
2334                 return per_cpu_ptr(tbl->stats, cpu);
2335         }
2336         return NULL;
2337 }
2338
2339 static void *neigh_stat_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2340 {
2341         struct proc_dir_entry *pde = seq->private;
2342         struct neigh_table *tbl = pde->data;
2343         int cpu;
2344
2345         for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
2346                 if (!cpu_possible(cpu))
2347                         continue;
2348                 *pos = cpu+1;
2349                 return per_cpu_ptr(tbl->stats, cpu);
2350         }
2351         return NULL;
2352 }
2353
2354 static void neigh_stat_seq_stop(struct seq_file *seq, void *v)
2355 {
2356
2357 }
2358
2359 static int neigh_stat_seq_show(struct seq_file *seq, void *v)
2360 {
2361         struct proc_dir_entry *pde = seq->private;
2362         struct neigh_table *tbl = pde->data;
2363         struct neigh_statistics *st = v;
2364
2365         if (v == SEQ_START_TOKEN) {
2366                 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");
2367                 return 0;
2368         }
2369
2370         seq_printf(seq, "%08x  %08lx %08lx %08lx  %08lx %08lx  %08lx  "
2371                         "%08lx %08lx  %08lx %08lx\n",
2372                    atomic_read(&tbl->entries),
2373
2374                    st->allocs,
2375                    st->destroys,
2376                    st->hash_grows,
2377
2378                    st->lookups,
2379                    st->hits,
2380
2381                    st->res_failed,
2382
2383                    st->rcv_probes_mcast,
2384                    st->rcv_probes_ucast,
2385
2386                    st->periodic_gc_runs,
2387                    st->forced_gc_runs
2388                    );
2389
2390         return 0;
2391 }
2392
2393 static struct seq_operations neigh_stat_seq_ops = {
2394         .start  = neigh_stat_seq_start,
2395         .next   = neigh_stat_seq_next,
2396         .stop   = neigh_stat_seq_stop,
2397         .show   = neigh_stat_seq_show,
2398 };
2399
2400 static int neigh_stat_seq_open(struct inode *inode, struct file *file)
2401 {
2402         int ret = seq_open(file, &neigh_stat_seq_ops);
2403
2404         if (!ret) {
2405                 struct seq_file *sf = file->private_data;
2406                 sf->private = PDE(inode);
2407         }
2408         return ret;
2409 };
2410
2411 static const struct file_operations neigh_stat_seq_fops = {
2412         .owner   = THIS_MODULE,
2413         .open    = neigh_stat_seq_open,
2414         .read    = seq_read,
2415         .llseek  = seq_lseek,
2416         .release = seq_release,
2417 };
2418
2419 #endif /* CONFIG_PROC_FS */
2420
2421 #ifdef CONFIG_ARPD
2422 static inline size_t neigh_nlmsg_size(void)
2423 {
2424         return NLMSG_ALIGN(sizeof(struct ndmsg))
2425                + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
2426                + nla_total_size(MAX_ADDR_LEN) /* NDA_LLADDR */
2427                + nla_total_size(sizeof(struct nda_cacheinfo))
2428                + nla_total_size(4); /* NDA_PROBES */
2429 }
2430
2431 static void __neigh_notify(struct neighbour *n, int type, int flags)
2432 {
2433         struct sk_buff *skb;
2434         int err = -ENOBUFS;
2435
2436         skb = nlmsg_new(neigh_nlmsg_size(), GFP_ATOMIC);
2437         if (skb == NULL)
2438                 goto errout;
2439
2440         err = neigh_fill_info(skb, n, 0, 0, type, flags);
2441         if (err < 0) {
2442                 /* -EMSGSIZE implies BUG in neigh_nlmsg_size() */
2443                 WARN_ON(err == -EMSGSIZE);
2444                 kfree_skb(skb);
2445                 goto errout;
2446         }
2447         err = rtnl_notify(skb, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
2448 errout:
2449         if (err < 0)
2450                 rtnl_set_sk_err(RTNLGRP_NEIGH, err);
2451 }
2452
2453 void neigh_app_ns(struct neighbour *n)
2454 {
2455         __neigh_notify(n, RTM_GETNEIGH, NLM_F_REQUEST);
2456 }
2457
2458 static void neigh_app_notify(struct neighbour *n)
2459 {
2460         __neigh_notify(n, RTM_NEWNEIGH, 0);
2461 }
2462
2463 #endif /* CONFIG_ARPD */
2464
2465 #ifdef CONFIG_SYSCTL
2466
2467 static struct neigh_sysctl_table {
2468         struct ctl_table_header *sysctl_header;
2469         ctl_table               neigh_vars[__NET_NEIGH_MAX];
2470         ctl_table               neigh_dev[2];
2471         ctl_table               neigh_neigh_dir[2];
2472         ctl_table               neigh_proto_dir[2];
2473         ctl_table               neigh_root_dir[2];
2474 } neigh_sysctl_template __read_mostly = {
2475         .neigh_vars = {
2476                 {
2477                         .ctl_name       = NET_NEIGH_MCAST_SOLICIT,
2478                         .procname       = "mcast_solicit",
2479                         .maxlen         = sizeof(int),
2480                         .mode           = 0644,
2481                         .proc_handler   = &proc_dointvec,
2482                 },
2483                 {
2484                         .ctl_name       = NET_NEIGH_UCAST_SOLICIT,
2485                         .procname       = "ucast_solicit",
2486                         .maxlen         = sizeof(int),
2487                         .mode           = 0644,
2488                         .proc_handler   = &proc_dointvec,
2489                 },
2490                 {
2491                         .ctl_name       = NET_NEIGH_APP_SOLICIT,
2492                         .procname       = "app_solicit",
2493                         .maxlen         = sizeof(int),
2494                         .mode           = 0644,
2495                         .proc_handler   = &proc_dointvec,
2496                 },
2497                 {
2498                         .ctl_name       = NET_NEIGH_RETRANS_TIME,
2499                         .procname       = "retrans_time",
2500                         .maxlen         = sizeof(int),
2501                         .mode           = 0644,
2502                         .proc_handler   = &proc_dointvec_userhz_jiffies,
2503                 },
2504                 {
2505                         .ctl_name       = NET_NEIGH_REACHABLE_TIME,
2506                         .procname       = "base_reachable_time",
2507                         .maxlen         = sizeof(int),
2508                         .mode           = 0644,
2509                         .proc_handler   = &proc_dointvec_jiffies,
2510                         .strategy       = &sysctl_jiffies,
2511                 },
2512                 {
2513                         .ctl_name       = NET_NEIGH_DELAY_PROBE_TIME,
2514                         .procname       = "delay_first_probe_time",
2515                         .maxlen         = sizeof(int),
2516                         .mode           = 0644,
2517                         .proc_handler   = &proc_dointvec_jiffies,
2518                         .strategy       = &sysctl_jiffies,
2519                 },
2520                 {
2521                         .ctl_name       = NET_NEIGH_GC_STALE_TIME,
2522                         .procname       = "gc_stale_time",
2523                         .maxlen         = sizeof(int),
2524                         .mode           = 0644,
2525                         .proc_handler   = &proc_dointvec_jiffies,
2526                         .strategy       = &sysctl_jiffies,
2527                 },
2528                 {
2529                         .ctl_name       = NET_NEIGH_UNRES_QLEN,
2530                         .procname       = "unres_qlen",
2531                         .maxlen         = sizeof(int),
2532                         .mode           = 0644,
2533                         .proc_handler   = &proc_dointvec,
2534                 },
2535                 {
2536                         .ctl_name       = NET_NEIGH_PROXY_QLEN,
2537                         .procname       = "proxy_qlen",
2538                         .maxlen         = sizeof(int),
2539                         .mode           = 0644,
2540                         .proc_handler   = &proc_dointvec,
2541                 },
2542                 {
2543                         .ctl_name       = NET_NEIGH_ANYCAST_DELAY,
2544                         .procname       = "anycast_delay",
2545                         .maxlen         = sizeof(int),
2546                         .mode           = 0644,
2547                         .proc_handler   = &proc_dointvec_userhz_jiffies,
2548                 },
2549                 {
2550                         .ctl_name       = NET_NEIGH_PROXY_DELAY,
2551                         .procname       = "proxy_delay",
2552                         .maxlen         = sizeof(int),
2553                         .mode           = 0644,
2554                         .proc_handler   = &proc_dointvec_userhz_jiffies,
2555                 },
2556                 {
2557                         .ctl_name       = NET_NEIGH_LOCKTIME,
2558                         .procname       = "locktime",
2559                         .maxlen         = sizeof(int),
2560                         .mode           = 0644,
2561                         .proc_handler   = &proc_dointvec_userhz_jiffies,
2562                 },
2563                 {
2564                         .ctl_name       = NET_NEIGH_GC_INTERVAL,
2565                         .procname       = "gc_interval",
2566                         .maxlen         = sizeof(int),
2567                         .mode           = 0644,
2568                         .proc_handler   = &proc_dointvec_jiffies,
2569                         .strategy       = &sysctl_jiffies,
2570                 },
2571                 {
2572                         .ctl_name       = NET_NEIGH_GC_THRESH1,
2573                         .procname       = "gc_thresh1",
2574                         .maxlen         = sizeof(int),
2575                         .mode           = 0644,
2576                         .proc_handler   = &proc_dointvec,
2577                 },
2578                 {
2579                         .ctl_name       = NET_NEIGH_GC_THRESH2,
2580                         .procname       = "gc_thresh2",
2581                         .maxlen         = sizeof(int),
2582                         .mode           = 0644,
2583                         .proc_handler   = &proc_dointvec,
2584                 },
2585                 {
2586                         .ctl_name       = NET_NEIGH_GC_THRESH3,
2587                         .procname       = "gc_thresh3",
2588                         .maxlen         = sizeof(int),
2589                         .mode           = 0644,
2590                         .proc_handler   = &proc_dointvec,
2591                 },
2592                 {
2593                         .ctl_name       = NET_NEIGH_RETRANS_TIME_MS,
2594                         .procname       = "retrans_time_ms",
2595                         .maxlen         = sizeof(int),
2596                         .mode           = 0644,
2597                         .proc_handler   = &proc_dointvec_ms_jiffies,
2598                         .strategy       = &sysctl_ms_jiffies,
2599                 },
2600                 {
2601                         .ctl_name       = NET_NEIGH_REACHABLE_TIME_MS,
2602                         .procname       = "base_reachable_time_ms",
2603                         .maxlen         = sizeof(int),
2604                         .mode           = 0644,
2605                         .proc_handler   = &proc_dointvec_ms_jiffies,
2606                         .strategy       = &sysctl_ms_jiffies,
2607                 },
2608         },
2609         .neigh_dev = {
2610                 {
2611                         .ctl_name       = NET_PROTO_CONF_DEFAULT,
2612                         .procname       = "default",
2613                         .mode           = 0555,
2614                 },
2615         },
2616         .neigh_neigh_dir = {
2617                 {
2618                         .procname       = "neigh",
2619                         .mode           = 0555,
2620                 },
2621         },
2622         .neigh_proto_dir = {
2623                 {
2624                         .mode           = 0555,
2625                 },
2626         },
2627         .neigh_root_dir = {
2628                 {
2629                         .ctl_name       = CTL_NET,
2630                         .procname       = "net",
2631                         .mode           = 0555,
2632                 },
2633         },
2634 };
2635
2636 int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
2637                           int p_id, int pdev_id, char *p_name,
2638                           proc_handler *handler, ctl_handler *strategy)
2639 {
2640         struct neigh_sysctl_table *t = kmemdup(&neigh_sysctl_template,
2641                                                sizeof(*t), GFP_KERNEL);
2642         const char *dev_name_source = NULL;
2643         char *dev_name = NULL;
2644         int err = 0;
2645
2646         if (!t)
2647                 return -ENOBUFS;
2648         t->neigh_vars[0].data  = &p->mcast_probes;
2649         t->neigh_vars[1].data  = &p->ucast_probes;
2650         t->neigh_vars[2].data  = &p->app_probes;
2651         t->neigh_vars[3].data  = &p->retrans_time;
2652         t->neigh_vars[4].data  = &p->base_reachable_time;
2653         t->neigh_vars[5].data  = &p->delay_probe_time;
2654         t->neigh_vars[6].data  = &p->gc_staletime;
2655         t->neigh_vars[7].data  = &p->queue_len;
2656         t->neigh_vars[8].data  = &p->proxy_qlen;
2657         t->neigh_vars[9].data  = &p->anycast_delay;
2658         t->neigh_vars[10].data = &p->proxy_delay;
2659         t->neigh_vars[11].data = &p->locktime;
2660
2661         if (dev) {
2662                 dev_name_source = dev->name;
2663                 t->neigh_dev[0].ctl_name = dev->ifindex;
2664                 t->neigh_vars[12].procname = NULL;
2665                 t->neigh_vars[13].procname = NULL;
2666                 t->neigh_vars[14].procname = NULL;
2667                 t->neigh_vars[15].procname = NULL;
2668         } else {
2669                 dev_name_source = t->neigh_dev[0].procname;
2670                 t->neigh_vars[12].data = (int *)(p + 1);
2671                 t->neigh_vars[13].data = (int *)(p + 1) + 1;
2672                 t->neigh_vars[14].data = (int *)(p + 1) + 2;
2673                 t->neigh_vars[15].data = (int *)(p + 1) + 3;
2674         }
2675
2676         t->neigh_vars[16].data  = &p->retrans_time;
2677         t->neigh_vars[17].data  = &p->base_reachable_time;
2678
2679         if (handler || strategy) {
2680                 /* RetransTime */
2681                 t->neigh_vars[3].proc_handler = handler;
2682                 t->neigh_vars[3].strategy = strategy;
2683                 t->neigh_vars[3].extra1 = dev;
2684                 /* ReachableTime */
2685                 t->neigh_vars[4].proc_handler = handler;
2686                 t->neigh_vars[4].strategy = strategy;
2687                 t->neigh_vars[4].extra1 = dev;
2688                 /* RetransTime (in milliseconds)*/
2689                 t->neigh_vars[16].proc_handler = handler;
2690                 t->neigh_vars[16].strategy = strategy;
2691                 t->neigh_vars[16].extra1 = dev;
2692                 /* ReachableTime (in milliseconds) */
2693                 t->neigh_vars[17].proc_handler = handler;
2694                 t->neigh_vars[17].strategy = strategy;
2695                 t->neigh_vars[17].extra1 = dev;
2696         }
2697
2698         dev_name = kstrdup(dev_name_source, GFP_KERNEL);
2699         if (!dev_name) {
2700                 err = -ENOBUFS;
2701                 goto free;
2702         }
2703
2704         t->neigh_dev[0].procname = dev_name;
2705
2706         t->neigh_neigh_dir[0].ctl_name = pdev_id;
2707
2708         t->neigh_proto_dir[0].procname = p_name;
2709         t->neigh_proto_dir[0].ctl_name = p_id;
2710
2711         t->neigh_dev[0].child          = t->neigh_vars;
2712         t->neigh_neigh_dir[0].child    = t->neigh_dev;
2713         t->neigh_proto_dir[0].child    = t->neigh_neigh_dir;
2714         t->neigh_root_dir[0].child     = t->neigh_proto_dir;
2715
2716         t->sysctl_header = register_sysctl_table(t->neigh_root_dir);
2717         if (!t->sysctl_header) {
2718                 err = -ENOBUFS;
2719                 goto free_procname;
2720         }
2721         p->sysctl_table = t;
2722         return 0;
2723
2724         /* error path */
2725  free_procname:
2726         kfree(dev_name);
2727  free:
2728         kfree(t);
2729
2730         return err;
2731 }
2732
2733 void neigh_sysctl_unregister(struct neigh_parms *p)
2734 {
2735         if (p->sysctl_table) {
2736                 struct neigh_sysctl_table *t = p->sysctl_table;
2737                 p->sysctl_table = NULL;
2738                 unregister_sysctl_table(t->sysctl_header);
2739                 kfree(t->neigh_dev[0].procname);
2740                 kfree(t);
2741         }
2742 }
2743
2744 #endif  /* CONFIG_SYSCTL */
2745
2746 EXPORT_SYMBOL(__neigh_event_send);
2747 EXPORT_SYMBOL(neigh_changeaddr);
2748 EXPORT_SYMBOL(neigh_compat_output);
2749 EXPORT_SYMBOL(neigh_connected_output);
2750 EXPORT_SYMBOL(neigh_create);
2751 EXPORT_SYMBOL(neigh_delete);
2752 EXPORT_SYMBOL(neigh_destroy);
2753 EXPORT_SYMBOL(neigh_dump_info);
2754 EXPORT_SYMBOL(neigh_event_ns);
2755 EXPORT_SYMBOL(neigh_ifdown);
2756 EXPORT_SYMBOL(neigh_lookup);
2757 EXPORT_SYMBOL(neigh_lookup_nodev);
2758 EXPORT_SYMBOL(neigh_parms_alloc);
2759 EXPORT_SYMBOL(neigh_parms_release);
2760 EXPORT_SYMBOL(neigh_rand_reach_time);
2761 EXPORT_SYMBOL(neigh_resolve_output);
2762 EXPORT_SYMBOL(neigh_table_clear);
2763 EXPORT_SYMBOL(neigh_table_init);
2764 EXPORT_SYMBOL(neigh_table_init_no_netlink);
2765 EXPORT_SYMBOL(neigh_update);
2766 EXPORT_SYMBOL(pneigh_enqueue);
2767 EXPORT_SYMBOL(pneigh_lookup);
2768
2769 #ifdef CONFIG_ARPD
2770 EXPORT_SYMBOL(neigh_app_ns);
2771 #endif
2772 #ifdef CONFIG_SYSCTL
2773 EXPORT_SYMBOL(neigh_sysctl_register);
2774 EXPORT_SYMBOL(neigh_sysctl_unregister);
2775 #endif