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v5.14.15
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *	Generic address resolution entity
   4 *
   5 *	Authors:
   6 *	Pedro Roque		<roque@di.fc.ul.pt>
   7 *	Alexey Kuznetsov	<kuznet@ms2.inr.ac.ru>
   8 *
 
 
 
 
 
   9 *	Fixes:
  10 *	Vitaly E. Lavrov	releasing NULL neighbor in neigh_add.
  11 *	Harald Welte		Add neighbour cache statistics like rtstat
  12 */
  13
  14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16#include <linux/slab.h>
  17#include <linux/kmemleak.h>
  18#include <linux/types.h>
  19#include <linux/kernel.h>
  20#include <linux/module.h>
  21#include <linux/socket.h>
  22#include <linux/netdevice.h>
  23#include <linux/proc_fs.h>
  24#ifdef CONFIG_SYSCTL
  25#include <linux/sysctl.h>
  26#endif
  27#include <linux/times.h>
  28#include <net/net_namespace.h>
  29#include <net/neighbour.h>
  30#include <net/arp.h>
  31#include <net/dst.h>
  32#include <net/sock.h>
  33#include <net/netevent.h>
  34#include <net/netlink.h>
  35#include <linux/rtnetlink.h>
  36#include <linux/random.h>
  37#include <linux/string.h>
  38#include <linux/log2.h>
  39#include <linux/inetdevice.h>
  40#include <net/addrconf.h>
  41
  42#include <trace/events/neigh.h>
  43
  44#define NEIGH_DEBUG 1
  45#define neigh_dbg(level, fmt, ...)		\
  46do {						\
  47	if (level <= NEIGH_DEBUG)		\
  48		pr_debug(fmt, ##__VA_ARGS__);	\
  49} while (0)
 
 
 
 
 
 
 
 
 
  50
  51#define PNEIGH_HASHMASK		0xF
  52
  53static void neigh_timer_handler(struct timer_list *t);
  54static void __neigh_notify(struct neighbour *n, int type, int flags,
  55			   u32 pid);
  56static void neigh_update_notify(struct neighbour *neigh, u32 nlmsg_pid);
  57static int pneigh_ifdown_and_unlock(struct neigh_table *tbl,
  58				    struct net_device *dev);
  59
 
  60#ifdef CONFIG_PROC_FS
  61static const struct seq_operations neigh_stat_seq_ops;
  62#endif
  63
  64/*
  65   Neighbour hash table buckets are protected with rwlock tbl->lock.
  66
  67   - All the scans/updates to hash buckets MUST be made under this lock.
  68   - NOTHING clever should be made under this lock: no callbacks
  69     to protocol backends, no attempts to send something to network.
  70     It will result in deadlocks, if backend/driver wants to use neighbour
  71     cache.
  72   - If the entry requires some non-trivial actions, increase
  73     its reference count and release table lock.
  74
  75   Neighbour entries are protected:
  76   - with reference count.
  77   - with rwlock neigh->lock
  78
  79   Reference count prevents destruction.
  80
  81   neigh->lock mainly serializes ll address data and its validity state.
  82   However, the same lock is used to protect another entry fields:
  83    - timer
  84    - resolution queue
  85
  86   Again, nothing clever shall be made under neigh->lock,
  87   the most complicated procedure, which we allow is dev->hard_header.
  88   It is supposed, that dev->hard_header is simplistic and does
  89   not make callbacks to neighbour tables.
 
 
 
  90 */
  91
 
 
  92static int neigh_blackhole(struct neighbour *neigh, struct sk_buff *skb)
  93{
  94	kfree_skb(skb);
  95	return -ENETDOWN;
  96}
  97
  98static void neigh_cleanup_and_release(struct neighbour *neigh)
  99{
 100	trace_neigh_cleanup_and_release(neigh, 0);
 101	__neigh_notify(neigh, RTM_DELNEIGH, 0, 0);
 102	call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
 
 103	neigh_release(neigh);
 104}
 105
 106/*
 107 * It is random distribution in the interval (1/2)*base...(3/2)*base.
 108 * It corresponds to default IPv6 settings and is not overridable,
 109 * because it is really reasonable choice.
 110 */
 111
 112unsigned long neigh_rand_reach_time(unsigned long base)
 113{
 114	return base ? (prandom_u32() % base) + (base >> 1) : 0;
 115}
 116EXPORT_SYMBOL(neigh_rand_reach_time);
 117
 118static void neigh_mark_dead(struct neighbour *n)
 119{
 120	n->dead = 1;
 121	if (!list_empty(&n->gc_list)) {
 122		list_del_init(&n->gc_list);
 123		atomic_dec(&n->tbl->gc_entries);
 124	}
 125}
 126
 127static void neigh_update_gc_list(struct neighbour *n)
 128{
 129	bool on_gc_list, exempt_from_gc;
 130
 131	write_lock_bh(&n->tbl->lock);
 132	write_lock(&n->lock);
 133
 134	if (n->dead)
 135		goto out;
 136
 137	/* remove from the gc list if new state is permanent or if neighbor
 138	 * is externally learned; otherwise entry should be on the gc list
 139	 */
 140	exempt_from_gc = n->nud_state & NUD_PERMANENT ||
 141			 n->flags & NTF_EXT_LEARNED;
 142	on_gc_list = !list_empty(&n->gc_list);
 143
 144	if (exempt_from_gc && on_gc_list) {
 145		list_del_init(&n->gc_list);
 146		atomic_dec(&n->tbl->gc_entries);
 147	} else if (!exempt_from_gc && !on_gc_list) {
 148		/* add entries to the tail; cleaning removes from the front */
 149		list_add_tail(&n->gc_list, &n->tbl->gc_list);
 150		atomic_inc(&n->tbl->gc_entries);
 151	}
 152
 153out:
 154	write_unlock(&n->lock);
 155	write_unlock_bh(&n->tbl->lock);
 156}
 157
 158static bool neigh_update_ext_learned(struct neighbour *neigh, u32 flags,
 159				     int *notify)
 160{
 161	bool rc = false;
 162	u8 ndm_flags;
 163
 164	if (!(flags & NEIGH_UPDATE_F_ADMIN))
 165		return rc;
 166
 167	ndm_flags = (flags & NEIGH_UPDATE_F_EXT_LEARNED) ? NTF_EXT_LEARNED : 0;
 168	if ((neigh->flags ^ ndm_flags) & NTF_EXT_LEARNED) {
 169		if (ndm_flags & NTF_EXT_LEARNED)
 170			neigh->flags |= NTF_EXT_LEARNED;
 171		else
 172			neigh->flags &= ~NTF_EXT_LEARNED;
 173		rc = true;
 174		*notify = 1;
 175	}
 176
 177	return rc;
 178}
 179
 180static bool neigh_del(struct neighbour *n, struct neighbour __rcu **np,
 181		      struct neigh_table *tbl)
 182{
 183	bool retval = false;
 184
 185	write_lock(&n->lock);
 186	if (refcount_read(&n->refcnt) == 1) {
 187		struct neighbour *neigh;
 188
 189		neigh = rcu_dereference_protected(n->next,
 190						  lockdep_is_held(&tbl->lock));
 191		rcu_assign_pointer(*np, neigh);
 192		neigh_mark_dead(n);
 193		retval = true;
 194	}
 195	write_unlock(&n->lock);
 196	if (retval)
 197		neigh_cleanup_and_release(n);
 198	return retval;
 199}
 200
 201bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl)
 202{
 203	struct neigh_hash_table *nht;
 204	void *pkey = ndel->primary_key;
 205	u32 hash_val;
 206	struct neighbour *n;
 207	struct neighbour __rcu **np;
 208
 209	nht = rcu_dereference_protected(tbl->nht,
 210					lockdep_is_held(&tbl->lock));
 211	hash_val = tbl->hash(pkey, ndel->dev, nht->hash_rnd);
 212	hash_val = hash_val >> (32 - nht->hash_shift);
 213
 214	np = &nht->hash_buckets[hash_val];
 215	while ((n = rcu_dereference_protected(*np,
 216					      lockdep_is_held(&tbl->lock)))) {
 217		if (n == ndel)
 218			return neigh_del(n, np, tbl);
 219		np = &n->next;
 220	}
 221	return false;
 222}
 223
 224static int neigh_forced_gc(struct neigh_table *tbl)
 225{
 226	int max_clean = atomic_read(&tbl->gc_entries) - tbl->gc_thresh2;
 227	unsigned long tref = jiffies - 5 * HZ;
 228	struct neighbour *n, *tmp;
 229	int shrunk = 0;
 
 
 230
 231	NEIGH_CACHE_STAT_INC(tbl, forced_gc_runs);
 232
 233	write_lock_bh(&tbl->lock);
 
 
 
 
 
 234
 235	list_for_each_entry_safe(n, tmp, &tbl->gc_list, gc_list) {
 236		if (refcount_read(&n->refcnt) == 1) {
 237			bool remove = false;
 238
 
 
 
 239			write_lock(&n->lock);
 240			if ((n->nud_state == NUD_FAILED) ||
 241			    (n->nud_state == NUD_NOARP) ||
 242			    (tbl->is_multicast &&
 243			     tbl->is_multicast(n->primary_key)) ||
 244			    time_after(tref, n->updated))
 245				remove = true;
 
 
 
 
 
 246			write_unlock(&n->lock);
 247
 248			if (remove && neigh_remove_one(n, tbl))
 249				shrunk++;
 250			if (shrunk >= max_clean)
 251				break;
 252		}
 253	}
 254
 255	tbl->last_flush = jiffies;
 256
 257	write_unlock_bh(&tbl->lock);
 258
 259	return shrunk;
 260}
 261
 262static void neigh_add_timer(struct neighbour *n, unsigned long when)
 263{
 264	neigh_hold(n);
 265	if (unlikely(mod_timer(&n->timer, when))) {
 266		printk("NEIGH: BUG, double timer add, state is %x\n",
 267		       n->nud_state);
 268		dump_stack();
 269	}
 270}
 271
 272static int neigh_del_timer(struct neighbour *n)
 273{
 274	if ((n->nud_state & NUD_IN_TIMER) &&
 275	    del_timer(&n->timer)) {
 276		neigh_release(n);
 277		return 1;
 278	}
 279	return 0;
 280}
 281
 282static void pneigh_queue_purge(struct sk_buff_head *list)
 283{
 284	struct sk_buff *skb;
 285
 286	while ((skb = skb_dequeue(list)) != NULL) {
 287		dev_put(skb->dev);
 288		kfree_skb(skb);
 289	}
 290}
 291
 292static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev,
 293			    bool skip_perm)
 294{
 295	int i;
 296	struct neigh_hash_table *nht;
 297
 298	nht = rcu_dereference_protected(tbl->nht,
 299					lockdep_is_held(&tbl->lock));
 300
 301	for (i = 0; i < (1 << nht->hash_shift); i++) {
 302		struct neighbour *n;
 303		struct neighbour __rcu **np = &nht->hash_buckets[i];
 304
 305		while ((n = rcu_dereference_protected(*np,
 306					lockdep_is_held(&tbl->lock))) != NULL) {
 307			if (dev && n->dev != dev) {
 308				np = &n->next;
 309				continue;
 310			}
 311			if (skip_perm && n->nud_state & NUD_PERMANENT) {
 312				np = &n->next;
 313				continue;
 314			}
 315			rcu_assign_pointer(*np,
 316				   rcu_dereference_protected(n->next,
 317						lockdep_is_held(&tbl->lock)));
 318			write_lock(&n->lock);
 319			neigh_del_timer(n);
 320			neigh_mark_dead(n);
 321			if (refcount_read(&n->refcnt) != 1) {
 
 322				/* The most unpleasant situation.
 323				   We must destroy neighbour entry,
 324				   but someone still uses it.
 325
 326				   The destroy will be delayed until
 327				   the last user releases us, but
 328				   we must kill timers etc. and move
 329				   it to safe state.
 330				 */
 331				__skb_queue_purge(&n->arp_queue);
 332				n->arp_queue_len_bytes = 0;
 333				n->output = neigh_blackhole;
 334				if (n->nud_state & NUD_VALID)
 335					n->nud_state = NUD_NOARP;
 336				else
 337					n->nud_state = NUD_NONE;
 338				neigh_dbg(2, "neigh %p is stray\n", n);
 339			}
 340			write_unlock(&n->lock);
 341			neigh_cleanup_and_release(n);
 342		}
 343	}
 344}
 345
 346void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev)
 347{
 348	write_lock_bh(&tbl->lock);
 349	neigh_flush_dev(tbl, dev, false);
 350	write_unlock_bh(&tbl->lock);
 351}
 352EXPORT_SYMBOL(neigh_changeaddr);
 353
 354static int __neigh_ifdown(struct neigh_table *tbl, struct net_device *dev,
 355			  bool skip_perm)
 356{
 357	write_lock_bh(&tbl->lock);
 358	neigh_flush_dev(tbl, dev, skip_perm);
 359	pneigh_ifdown_and_unlock(tbl, dev);
 
 360
 361	del_timer_sync(&tbl->proxy_timer);
 362	pneigh_queue_purge(&tbl->proxy_queue);
 363	return 0;
 364}
 365
 366int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev)
 367{
 368	__neigh_ifdown(tbl, dev, true);
 369	return 0;
 370}
 371EXPORT_SYMBOL(neigh_carrier_down);
 372
 373int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 374{
 375	__neigh_ifdown(tbl, dev, false);
 376	return 0;
 377}
 378EXPORT_SYMBOL(neigh_ifdown);
 379
 380static struct neighbour *neigh_alloc(struct neigh_table *tbl,
 381				     struct net_device *dev,
 382				     bool exempt_from_gc)
 383{
 384	struct neighbour *n = NULL;
 385	unsigned long now = jiffies;
 386	int entries;
 387
 388	if (exempt_from_gc)
 389		goto do_alloc;
 390
 391	entries = atomic_inc_return(&tbl->gc_entries) - 1;
 392	if (entries >= tbl->gc_thresh3 ||
 393	    (entries >= tbl->gc_thresh2 &&
 394	     time_after(now, tbl->last_flush + 5 * HZ))) {
 395		if (!neigh_forced_gc(tbl) &&
 396		    entries >= tbl->gc_thresh3) {
 397			net_info_ratelimited("%s: neighbor table overflow!\n",
 398					     tbl->id);
 399			NEIGH_CACHE_STAT_INC(tbl, table_fulls);
 400			goto out_entries;
 401		}
 402	}
 403
 404do_alloc:
 405	n = kzalloc(tbl->entry_size + dev->neigh_priv_len, GFP_ATOMIC);
 
 
 
 
 
 
 
 406	if (!n)
 407		goto out_entries;
 408
 409	__skb_queue_head_init(&n->arp_queue);
 410	rwlock_init(&n->lock);
 411	seqlock_init(&n->ha_lock);
 412	n->updated	  = n->used = now;
 413	n->nud_state	  = NUD_NONE;
 414	n->output	  = neigh_blackhole;
 415	seqlock_init(&n->hh.hh_lock);
 416	n->parms	  = neigh_parms_clone(&tbl->parms);
 417	timer_setup(&n->timer, neigh_timer_handler, 0);
 418
 419	NEIGH_CACHE_STAT_INC(tbl, allocs);
 420	n->tbl		  = tbl;
 421	refcount_set(&n->refcnt, 1);
 422	n->dead		  = 1;
 423	INIT_LIST_HEAD(&n->gc_list);
 424
 425	atomic_inc(&tbl->entries);
 426out:
 427	return n;
 428
 429out_entries:
 430	if (!exempt_from_gc)
 431		atomic_dec(&tbl->gc_entries);
 432	goto out;
 433}
 434
 435static void neigh_get_hash_rnd(u32 *x)
 436{
 437	*x = get_random_u32() | 1;
 
 438}
 439
 440static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift)
 441{
 442	size_t size = (1 << shift) * sizeof(struct neighbour *);
 443	struct neigh_hash_table *ret;
 444	struct neighbour __rcu **buckets;
 445	int i;
 446
 447	ret = kmalloc(sizeof(*ret), GFP_ATOMIC);
 448	if (!ret)
 449		return NULL;
 450	if (size <= PAGE_SIZE) {
 451		buckets = kzalloc(size, GFP_ATOMIC);
 452	} else {
 453		buckets = (struct neighbour __rcu **)
 454			  __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
 455					   get_order(size));
 456		kmemleak_alloc(buckets, size, 1, GFP_ATOMIC);
 457	}
 458	if (!buckets) {
 459		kfree(ret);
 460		return NULL;
 461	}
 462	ret->hash_buckets = buckets;
 463	ret->hash_shift = shift;
 464	for (i = 0; i < NEIGH_NUM_HASH_RND; i++)
 465		neigh_get_hash_rnd(&ret->hash_rnd[i]);
 466	return ret;
 467}
 468
 469static void neigh_hash_free_rcu(struct rcu_head *head)
 470{
 471	struct neigh_hash_table *nht = container_of(head,
 472						    struct neigh_hash_table,
 473						    rcu);
 474	size_t size = (1 << nht->hash_shift) * sizeof(struct neighbour *);
 475	struct neighbour __rcu **buckets = nht->hash_buckets;
 476
 477	if (size <= PAGE_SIZE) {
 478		kfree(buckets);
 479	} else {
 480		kmemleak_free(buckets);
 481		free_pages((unsigned long)buckets, get_order(size));
 482	}
 483	kfree(nht);
 484}
 485
 486static struct neigh_hash_table *neigh_hash_grow(struct neigh_table *tbl,
 487						unsigned long new_shift)
 488{
 489	unsigned int i, hash;
 490	struct neigh_hash_table *new_nht, *old_nht;
 491
 492	NEIGH_CACHE_STAT_INC(tbl, hash_grows);
 493
 494	old_nht = rcu_dereference_protected(tbl->nht,
 495					    lockdep_is_held(&tbl->lock));
 496	new_nht = neigh_hash_alloc(new_shift);
 497	if (!new_nht)
 498		return old_nht;
 499
 500	for (i = 0; i < (1 << old_nht->hash_shift); i++) {
 501		struct neighbour *n, *next;
 502
 503		for (n = rcu_dereference_protected(old_nht->hash_buckets[i],
 504						   lockdep_is_held(&tbl->lock));
 505		     n != NULL;
 506		     n = next) {
 507			hash = tbl->hash(n->primary_key, n->dev,
 508					 new_nht->hash_rnd);
 509
 510			hash >>= (32 - new_nht->hash_shift);
 511			next = rcu_dereference_protected(n->next,
 512						lockdep_is_held(&tbl->lock));
 513
 514			rcu_assign_pointer(n->next,
 515					   rcu_dereference_protected(
 516						new_nht->hash_buckets[hash],
 517						lockdep_is_held(&tbl->lock)));
 518			rcu_assign_pointer(new_nht->hash_buckets[hash], n);
 519		}
 520	}
 521
 522	rcu_assign_pointer(tbl->nht, new_nht);
 523	call_rcu(&old_nht->rcu, neigh_hash_free_rcu);
 524	return new_nht;
 525}
 526
 527struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
 528			       struct net_device *dev)
 529{
 530	struct neighbour *n;
 
 
 
 531
 532	NEIGH_CACHE_STAT_INC(tbl, lookups);
 533
 534	rcu_read_lock_bh();
 535	n = __neigh_lookup_noref(tbl, pkey, dev);
 536	if (n) {
 537		if (!refcount_inc_not_zero(&n->refcnt))
 538			n = NULL;
 539		NEIGH_CACHE_STAT_INC(tbl, hits);
 
 
 
 
 
 
 
 540	}
 541
 542	rcu_read_unlock_bh();
 543	return n;
 544}
 545EXPORT_SYMBOL(neigh_lookup);
 546
 547struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
 548				     const void *pkey)
 549{
 550	struct neighbour *n;
 551	unsigned int key_len = tbl->key_len;
 552	u32 hash_val;
 553	struct neigh_hash_table *nht;
 554
 555	NEIGH_CACHE_STAT_INC(tbl, lookups);
 556
 557	rcu_read_lock_bh();
 558	nht = rcu_dereference_bh(tbl->nht);
 559	hash_val = tbl->hash(pkey, NULL, nht->hash_rnd) >> (32 - nht->hash_shift);
 560
 561	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
 562	     n != NULL;
 563	     n = rcu_dereference_bh(n->next)) {
 564		if (!memcmp(n->primary_key, pkey, key_len) &&
 565		    net_eq(dev_net(n->dev), net)) {
 566			if (!refcount_inc_not_zero(&n->refcnt))
 567				n = NULL;
 568			NEIGH_CACHE_STAT_INC(tbl, hits);
 569			break;
 570		}
 571	}
 572
 573	rcu_read_unlock_bh();
 574	return n;
 575}
 576EXPORT_SYMBOL(neigh_lookup_nodev);
 577
 578static struct neighbour *___neigh_create(struct neigh_table *tbl,
 579					 const void *pkey,
 580					 struct net_device *dev,
 581					 bool exempt_from_gc, bool want_ref)
 582{
 583	struct neighbour *n1, *rc, *n = neigh_alloc(tbl, dev, exempt_from_gc);
 584	u32 hash_val;
 585	unsigned int key_len = tbl->key_len;
 586	int error;
 
 587	struct neigh_hash_table *nht;
 588
 589	trace_neigh_create(tbl, dev, pkey, n, exempt_from_gc);
 590
 591	if (!n) {
 592		rc = ERR_PTR(-ENOBUFS);
 593		goto out;
 594	}
 595
 596	memcpy(n->primary_key, pkey, key_len);
 597	n->dev = dev;
 598	dev_hold(dev);
 599
 600	/* Protocol specific setup. */
 601	if (tbl->constructor &&	(error = tbl->constructor(n)) < 0) {
 602		rc = ERR_PTR(error);
 603		goto out_neigh_release;
 604	}
 605
 606	if (dev->netdev_ops->ndo_neigh_construct) {
 607		error = dev->netdev_ops->ndo_neigh_construct(dev, n);
 608		if (error < 0) {
 609			rc = ERR_PTR(error);
 610			goto out_neigh_release;
 611		}
 612	}
 613
 614	/* Device specific setup. */
 615	if (n->parms->neigh_setup &&
 616	    (error = n->parms->neigh_setup(n)) < 0) {
 617		rc = ERR_PTR(error);
 618		goto out_neigh_release;
 619	}
 620
 621	n->confirmed = jiffies - (NEIGH_VAR(n->parms, BASE_REACHABLE_TIME) << 1);
 622
 623	write_lock_bh(&tbl->lock);
 624	nht = rcu_dereference_protected(tbl->nht,
 625					lockdep_is_held(&tbl->lock));
 626
 627	if (atomic_read(&tbl->entries) > (1 << nht->hash_shift))
 628		nht = neigh_hash_grow(tbl, nht->hash_shift + 1);
 629
 630	hash_val = tbl->hash(n->primary_key, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
 631
 632	if (n->parms->dead) {
 633		rc = ERR_PTR(-EINVAL);
 634		goto out_tbl_unlock;
 635	}
 636
 637	for (n1 = rcu_dereference_protected(nht->hash_buckets[hash_val],
 638					    lockdep_is_held(&tbl->lock));
 639	     n1 != NULL;
 640	     n1 = rcu_dereference_protected(n1->next,
 641			lockdep_is_held(&tbl->lock))) {
 642		if (dev == n1->dev && !memcmp(n1->primary_key, n->primary_key, key_len)) {
 643			if (want_ref)
 644				neigh_hold(n1);
 645			rc = n1;
 646			goto out_tbl_unlock;
 647		}
 648	}
 649
 650	n->dead = 0;
 651	if (!exempt_from_gc)
 652		list_add_tail(&n->gc_list, &n->tbl->gc_list);
 653
 654	if (want_ref)
 655		neigh_hold(n);
 656	rcu_assign_pointer(n->next,
 657			   rcu_dereference_protected(nht->hash_buckets[hash_val],
 658						     lockdep_is_held(&tbl->lock)));
 659	rcu_assign_pointer(nht->hash_buckets[hash_val], n);
 660	write_unlock_bh(&tbl->lock);
 661	neigh_dbg(2, "neigh %p is created\n", n);
 662	rc = n;
 663out:
 664	return rc;
 665out_tbl_unlock:
 666	write_unlock_bh(&tbl->lock);
 667out_neigh_release:
 668	if (!exempt_from_gc)
 669		atomic_dec(&tbl->gc_entries);
 670	neigh_release(n);
 671	goto out;
 672}
 
 673
 674struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
 675				 struct net_device *dev, bool want_ref)
 676{
 677	return ___neigh_create(tbl, pkey, dev, false, want_ref);
 678}
 679EXPORT_SYMBOL(__neigh_create);
 680
 681static u32 pneigh_hash(const void *pkey, unsigned int key_len)
 682{
 683	u32 hash_val = *(u32 *)(pkey + key_len - 4);
 684	hash_val ^= (hash_val >> 16);
 685	hash_val ^= hash_val >> 8;
 686	hash_val ^= hash_val >> 4;
 687	hash_val &= PNEIGH_HASHMASK;
 688	return hash_val;
 689}
 690
 691static struct pneigh_entry *__pneigh_lookup_1(struct pneigh_entry *n,
 692					      struct net *net,
 693					      const void *pkey,
 694					      unsigned int key_len,
 695					      struct net_device *dev)
 696{
 697	while (n) {
 698		if (!memcmp(n->key, pkey, key_len) &&
 699		    net_eq(pneigh_net(n), net) &&
 700		    (n->dev == dev || !n->dev))
 701			return n;
 702		n = n->next;
 703	}
 704	return NULL;
 705}
 706
 707struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl,
 708		struct net *net, const void *pkey, struct net_device *dev)
 709{
 710	unsigned int key_len = tbl->key_len;
 711	u32 hash_val = pneigh_hash(pkey, key_len);
 712
 713	return __pneigh_lookup_1(tbl->phash_buckets[hash_val],
 714				 net, pkey, key_len, dev);
 715}
 716EXPORT_SYMBOL_GPL(__pneigh_lookup);
 717
 718struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl,
 719				    struct net *net, const void *pkey,
 720				    struct net_device *dev, int creat)
 721{
 722	struct pneigh_entry *n;
 723	unsigned int key_len = tbl->key_len;
 724	u32 hash_val = pneigh_hash(pkey, key_len);
 725
 726	read_lock_bh(&tbl->lock);
 727	n = __pneigh_lookup_1(tbl->phash_buckets[hash_val],
 728			      net, pkey, key_len, dev);
 729	read_unlock_bh(&tbl->lock);
 730
 731	if (n || !creat)
 732		goto out;
 733
 734	ASSERT_RTNL();
 735
 736	n = kmalloc(sizeof(*n) + key_len, GFP_KERNEL);
 737	if (!n)
 738		goto out;
 739
 740	n->protocol = 0;
 741	write_pnet(&n->net, net);
 742	memcpy(n->key, pkey, key_len);
 743	n->dev = dev;
 744	if (dev)
 745		dev_hold(dev);
 746
 747	if (tbl->pconstructor && tbl->pconstructor(n)) {
 748		if (dev)
 749			dev_put(dev);
 
 750		kfree(n);
 751		n = NULL;
 752		goto out;
 753	}
 754
 755	write_lock_bh(&tbl->lock);
 756	n->next = tbl->phash_buckets[hash_val];
 757	tbl->phash_buckets[hash_val] = n;
 758	write_unlock_bh(&tbl->lock);
 759out:
 760	return n;
 761}
 762EXPORT_SYMBOL(pneigh_lookup);
 763
 764
 765int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *pkey,
 766		  struct net_device *dev)
 767{
 768	struct pneigh_entry *n, **np;
 769	unsigned int key_len = tbl->key_len;
 770	u32 hash_val = pneigh_hash(pkey, key_len);
 771
 772	write_lock_bh(&tbl->lock);
 773	for (np = &tbl->phash_buckets[hash_val]; (n = *np) != NULL;
 774	     np = &n->next) {
 775		if (!memcmp(n->key, pkey, key_len) && n->dev == dev &&
 776		    net_eq(pneigh_net(n), net)) {
 777			*np = n->next;
 778			write_unlock_bh(&tbl->lock);
 779			if (tbl->pdestructor)
 780				tbl->pdestructor(n);
 781			if (n->dev)
 782				dev_put(n->dev);
 
 783			kfree(n);
 784			return 0;
 785		}
 786	}
 787	write_unlock_bh(&tbl->lock);
 788	return -ENOENT;
 789}
 790
 791static int pneigh_ifdown_and_unlock(struct neigh_table *tbl,
 792				    struct net_device *dev)
 793{
 794	struct pneigh_entry *n, **np, *freelist = NULL;
 795	u32 h;
 796
 797	for (h = 0; h <= PNEIGH_HASHMASK; h++) {
 798		np = &tbl->phash_buckets[h];
 799		while ((n = *np) != NULL) {
 800			if (!dev || n->dev == dev) {
 801				*np = n->next;
 802				n->next = freelist;
 803				freelist = n;
 
 
 
 
 804				continue;
 805			}
 806			np = &n->next;
 807		}
 808	}
 809	write_unlock_bh(&tbl->lock);
 810	while ((n = freelist)) {
 811		freelist = n->next;
 812		n->next = NULL;
 813		if (tbl->pdestructor)
 814			tbl->pdestructor(n);
 815		if (n->dev)
 816			dev_put(n->dev);
 817		kfree(n);
 818	}
 819	return -ENOENT;
 820}
 821
 822static void neigh_parms_destroy(struct neigh_parms *parms);
 823
 824static inline void neigh_parms_put(struct neigh_parms *parms)
 825{
 826	if (refcount_dec_and_test(&parms->refcnt))
 827		neigh_parms_destroy(parms);
 828}
 829
 830/*
 831 *	neighbour must already be out of the table;
 832 *
 833 */
 834void neigh_destroy(struct neighbour *neigh)
 835{
 836	struct net_device *dev = neigh->dev;
 837
 838	NEIGH_CACHE_STAT_INC(neigh->tbl, destroys);
 839
 840	if (!neigh->dead) {
 841		pr_warn("Destroying alive neighbour %p\n", neigh);
 842		dump_stack();
 843		return;
 844	}
 845
 846	if (neigh_del_timer(neigh))
 847		pr_warn("Impossible event\n");
 848
 849	write_lock_bh(&neigh->lock);
 850	__skb_queue_purge(&neigh->arp_queue);
 851	write_unlock_bh(&neigh->lock);
 852	neigh->arp_queue_len_bytes = 0;
 853
 854	if (dev->netdev_ops->ndo_neigh_destroy)
 855		dev->netdev_ops->ndo_neigh_destroy(dev, neigh);
 856
 857	dev_put(dev);
 858	neigh_parms_put(neigh->parms);
 859
 860	neigh_dbg(2, "neigh %p is destroyed\n", neigh);
 861
 862	atomic_dec(&neigh->tbl->entries);
 863	kfree_rcu(neigh, rcu);
 864}
 865EXPORT_SYMBOL(neigh_destroy);
 866
 867/* Neighbour state is suspicious;
 868   disable fast path.
 869
 870   Called with write_locked neigh.
 871 */
 872static void neigh_suspect(struct neighbour *neigh)
 873{
 874	neigh_dbg(2, "neigh %p is suspected\n", neigh);
 875
 876	neigh->output = neigh->ops->output;
 877}
 878
 879/* Neighbour state is OK;
 880   enable fast path.
 881
 882   Called with write_locked neigh.
 883 */
 884static void neigh_connect(struct neighbour *neigh)
 885{
 886	neigh_dbg(2, "neigh %p is connected\n", neigh);
 887
 888	neigh->output = neigh->ops->connected_output;
 889}
 890
 891static void neigh_periodic_work(struct work_struct *work)
 892{
 893	struct neigh_table *tbl = container_of(work, struct neigh_table, gc_work.work);
 894	struct neighbour *n;
 895	struct neighbour __rcu **np;
 896	unsigned int i;
 897	struct neigh_hash_table *nht;
 898
 899	NEIGH_CACHE_STAT_INC(tbl, periodic_gc_runs);
 900
 901	write_lock_bh(&tbl->lock);
 902	nht = rcu_dereference_protected(tbl->nht,
 903					lockdep_is_held(&tbl->lock));
 904
 905	/*
 906	 *	periodically recompute ReachableTime from random function
 907	 */
 908
 909	if (time_after(jiffies, tbl->last_rand + 300 * HZ)) {
 910		struct neigh_parms *p;
 911		tbl->last_rand = jiffies;
 912		list_for_each_entry(p, &tbl->parms_list, list)
 913			p->reachable_time =
 914				neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
 915	}
 916
 917	if (atomic_read(&tbl->entries) < tbl->gc_thresh1)
 918		goto out;
 919
 920	for (i = 0 ; i < (1 << nht->hash_shift); i++) {
 921		np = &nht->hash_buckets[i];
 922
 923		while ((n = rcu_dereference_protected(*np,
 924				lockdep_is_held(&tbl->lock))) != NULL) {
 925			unsigned int state;
 926
 927			write_lock(&n->lock);
 928
 929			state = n->nud_state;
 930			if ((state & (NUD_PERMANENT | NUD_IN_TIMER)) ||
 931			    (n->flags & NTF_EXT_LEARNED)) {
 932				write_unlock(&n->lock);
 933				goto next_elt;
 934			}
 935
 936			if (time_before(n->used, n->confirmed))
 937				n->used = n->confirmed;
 938
 939			if (refcount_read(&n->refcnt) == 1 &&
 940			    (state == NUD_FAILED ||
 941			     time_after(jiffies, n->used + NEIGH_VAR(n->parms, GC_STALETIME)))) {
 942				*np = n->next;
 943				neigh_mark_dead(n);
 944				write_unlock(&n->lock);
 945				neigh_cleanup_and_release(n);
 946				continue;
 947			}
 948			write_unlock(&n->lock);
 949
 950next_elt:
 951			np = &n->next;
 952		}
 953		/*
 954		 * It's fine to release lock here, even if hash table
 955		 * grows while we are preempted.
 956		 */
 957		write_unlock_bh(&tbl->lock);
 958		cond_resched();
 959		write_lock_bh(&tbl->lock);
 960		nht = rcu_dereference_protected(tbl->nht,
 961						lockdep_is_held(&tbl->lock));
 962	}
 963out:
 964	/* Cycle through all hash buckets every BASE_REACHABLE_TIME/2 ticks.
 965	 * ARP entry timeouts range from 1/2 BASE_REACHABLE_TIME to 3/2
 966	 * BASE_REACHABLE_TIME.
 967	 */
 968	queue_delayed_work(system_power_efficient_wq, &tbl->gc_work,
 969			      NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME) >> 1);
 970	write_unlock_bh(&tbl->lock);
 971}
 972
 973static __inline__ int neigh_max_probes(struct neighbour *n)
 974{
 975	struct neigh_parms *p = n->parms;
 976	return NEIGH_VAR(p, UCAST_PROBES) + NEIGH_VAR(p, APP_PROBES) +
 977	       (n->nud_state & NUD_PROBE ? NEIGH_VAR(p, MCAST_REPROBES) :
 978	        NEIGH_VAR(p, MCAST_PROBES));
 979}
 980
 981static void neigh_invalidate(struct neighbour *neigh)
 982	__releases(neigh->lock)
 983	__acquires(neigh->lock)
 984{
 985	struct sk_buff *skb;
 986
 987	NEIGH_CACHE_STAT_INC(neigh->tbl, res_failed);
 988	neigh_dbg(2, "neigh %p is failed\n", neigh);
 989	neigh->updated = jiffies;
 990
 991	/* It is very thin place. report_unreachable is very complicated
 992	   routine. Particularly, it can hit the same neighbour entry!
 993
 994	   So that, we try to be accurate and avoid dead loop. --ANK
 995	 */
 996	while (neigh->nud_state == NUD_FAILED &&
 997	       (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
 998		write_unlock(&neigh->lock);
 999		neigh->ops->error_report(neigh, skb);
1000		write_lock(&neigh->lock);
1001	}
1002	__skb_queue_purge(&neigh->arp_queue);
1003	neigh->arp_queue_len_bytes = 0;
1004}
1005
1006static void neigh_probe(struct neighbour *neigh)
1007	__releases(neigh->lock)
1008{
1009	struct sk_buff *skb = skb_peek_tail(&neigh->arp_queue);
1010	/* keep skb alive even if arp_queue overflows */
1011	if (skb)
1012		skb = skb_clone(skb, GFP_ATOMIC);
1013	write_unlock(&neigh->lock);
1014	if (neigh->ops->solicit)
1015		neigh->ops->solicit(neigh, skb);
1016	atomic_inc(&neigh->probes);
1017	consume_skb(skb);
1018}
1019
1020/* Called when a timer expires for a neighbour entry. */
1021
1022static void neigh_timer_handler(struct timer_list *t)
1023{
1024	unsigned long now, next;
1025	struct neighbour *neigh = from_timer(neigh, t, timer);
1026	unsigned int state;
1027	int notify = 0;
1028
1029	write_lock(&neigh->lock);
1030
1031	state = neigh->nud_state;
1032	now = jiffies;
1033	next = now + HZ;
1034
1035	if (!(state & NUD_IN_TIMER))
1036		goto out;
1037
1038	if (state & NUD_REACHABLE) {
1039		if (time_before_eq(now,
1040				   neigh->confirmed + neigh->parms->reachable_time)) {
1041			neigh_dbg(2, "neigh %p is still alive\n", neigh);
1042			next = neigh->confirmed + neigh->parms->reachable_time;
1043		} else if (time_before_eq(now,
1044					  neigh->used +
1045					  NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME))) {
1046			neigh_dbg(2, "neigh %p is delayed\n", neigh);
1047			neigh->nud_state = NUD_DELAY;
1048			neigh->updated = jiffies;
1049			neigh_suspect(neigh);
1050			next = now + NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME);
1051		} else {
1052			neigh_dbg(2, "neigh %p is suspected\n", neigh);
1053			neigh->nud_state = NUD_STALE;
1054			neigh->updated = jiffies;
1055			neigh_suspect(neigh);
1056			notify = 1;
1057		}
1058	} else if (state & NUD_DELAY) {
1059		if (time_before_eq(now,
1060				   neigh->confirmed +
1061				   NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME))) {
1062			neigh_dbg(2, "neigh %p is now reachable\n", neigh);
1063			neigh->nud_state = NUD_REACHABLE;
1064			neigh->updated = jiffies;
1065			neigh_connect(neigh);
1066			notify = 1;
1067			next = neigh->confirmed + neigh->parms->reachable_time;
1068		} else {
1069			neigh_dbg(2, "neigh %p is probed\n", neigh);
1070			neigh->nud_state = NUD_PROBE;
1071			neigh->updated = jiffies;
1072			atomic_set(&neigh->probes, 0);
1073			notify = 1;
1074			next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),
1075					 HZ/100);
1076		}
1077	} else {
1078		/* NUD_PROBE|NUD_INCOMPLETE */
1079		next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME), HZ/100);
1080	}
1081
1082	if ((neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) &&
1083	    atomic_read(&neigh->probes) >= neigh_max_probes(neigh)) {
1084		neigh->nud_state = NUD_FAILED;
1085		notify = 1;
1086		neigh_invalidate(neigh);
1087		goto out;
1088	}
1089
1090	if (neigh->nud_state & NUD_IN_TIMER) {
1091		if (time_before(next, jiffies + HZ/100))
1092			next = jiffies + HZ/100;
1093		if (!mod_timer(&neigh->timer, next))
1094			neigh_hold(neigh);
1095	}
1096	if (neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) {
1097		neigh_probe(neigh);
1098	} else {
1099out:
1100		write_unlock(&neigh->lock);
1101	}
1102
1103	if (notify)
1104		neigh_update_notify(neigh, 0);
1105
1106	trace_neigh_timer_handler(neigh, 0);
1107
1108	neigh_release(neigh);
1109}
1110
1111int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
1112{
1113	int rc;
1114	bool immediate_probe = false;
1115
1116	write_lock_bh(&neigh->lock);
1117
1118	rc = 0;
1119	if (neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE))
1120		goto out_unlock_bh;
1121	if (neigh->dead)
1122		goto out_dead;
1123
1124	if (!(neigh->nud_state & (NUD_STALE | NUD_INCOMPLETE))) {
1125		if (NEIGH_VAR(neigh->parms, MCAST_PROBES) +
1126		    NEIGH_VAR(neigh->parms, APP_PROBES)) {
1127			unsigned long next, now = jiffies;
1128
1129			atomic_set(&neigh->probes,
1130				   NEIGH_VAR(neigh->parms, UCAST_PROBES));
1131			neigh_del_timer(neigh);
1132			neigh->nud_state     = NUD_INCOMPLETE;
1133			neigh->updated = now;
1134			next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),
1135					 HZ/100);
1136			neigh_add_timer(neigh, next);
1137			immediate_probe = true;
1138		} else {
1139			neigh->nud_state = NUD_FAILED;
1140			neigh->updated = jiffies;
1141			write_unlock_bh(&neigh->lock);
1142
1143			kfree_skb(skb);
1144			return 1;
1145		}
1146	} else if (neigh->nud_state & NUD_STALE) {
1147		neigh_dbg(2, "neigh %p is delayed\n", neigh);
1148		neigh_del_timer(neigh);
1149		neigh->nud_state = NUD_DELAY;
1150		neigh->updated = jiffies;
1151		neigh_add_timer(neigh, jiffies +
1152				NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME));
1153	}
1154
1155	if (neigh->nud_state == NUD_INCOMPLETE) {
1156		if (skb) {
1157			while (neigh->arp_queue_len_bytes + skb->truesize >
1158			       NEIGH_VAR(neigh->parms, QUEUE_LEN_BYTES)) {
1159				struct sk_buff *buff;
1160
1161				buff = __skb_dequeue(&neigh->arp_queue);
1162				if (!buff)
1163					break;
1164				neigh->arp_queue_len_bytes -= buff->truesize;
1165				kfree_skb(buff);
1166				NEIGH_CACHE_STAT_INC(neigh->tbl, unres_discards);
1167			}
1168			skb_dst_force(skb);
1169			__skb_queue_tail(&neigh->arp_queue, skb);
1170			neigh->arp_queue_len_bytes += skb->truesize;
1171		}
1172		rc = 1;
1173	}
1174out_unlock_bh:
1175	if (immediate_probe)
1176		neigh_probe(neigh);
1177	else
1178		write_unlock(&neigh->lock);
1179	local_bh_enable();
1180	trace_neigh_event_send_done(neigh, rc);
1181	return rc;
1182
1183out_dead:
1184	if (neigh->nud_state & NUD_STALE)
1185		goto out_unlock_bh;
1186	write_unlock_bh(&neigh->lock);
1187	kfree_skb(skb);
1188	trace_neigh_event_send_dead(neigh, 1);
1189	return 1;
1190}
1191EXPORT_SYMBOL(__neigh_event_send);
1192
1193static void neigh_update_hhs(struct neighbour *neigh)
1194{
1195	struct hh_cache *hh;
1196	void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *)
1197		= NULL;
1198
1199	if (neigh->dev->header_ops)
1200		update = neigh->dev->header_ops->cache_update;
1201
1202	if (update) {
1203		hh = &neigh->hh;
1204		if (READ_ONCE(hh->hh_len)) {
1205			write_seqlock_bh(&hh->hh_lock);
1206			update(hh, neigh->dev, neigh->ha);
1207			write_sequnlock_bh(&hh->hh_lock);
1208		}
1209	}
1210}
1211
1212
1213
1214/* Generic update routine.
1215   -- lladdr is new lladdr or NULL, if it is not supplied.
1216   -- new    is new state.
1217   -- flags
1218	NEIGH_UPDATE_F_OVERRIDE allows to override existing lladdr,
1219				if it is different.
1220	NEIGH_UPDATE_F_WEAK_OVERRIDE will suspect existing "connected"
1221				lladdr instead of overriding it
1222				if it is different.
 
 
1223	NEIGH_UPDATE_F_ADMIN	means that the change is administrative.
1224
1225	NEIGH_UPDATE_F_OVERRIDE_ISROUTER allows to override existing
1226				NTF_ROUTER flag.
1227	NEIGH_UPDATE_F_ISROUTER	indicates if the neighbour is known as
1228				a router.
1229
1230   Caller MUST hold reference count on the entry.
1231 */
1232
1233static int __neigh_update(struct neighbour *neigh, const u8 *lladdr,
1234			  u8 new, u32 flags, u32 nlmsg_pid,
1235			  struct netlink_ext_ack *extack)
1236{
1237	bool ext_learn_change = false;
1238	u8 old;
1239	int err;
1240	int notify = 0;
1241	struct net_device *dev;
1242	int update_isrouter = 0;
1243
1244	trace_neigh_update(neigh, lladdr, new, flags, nlmsg_pid);
1245
1246	write_lock_bh(&neigh->lock);
1247
1248	dev    = neigh->dev;
1249	old    = neigh->nud_state;
1250	err    = -EPERM;
1251
1252	if (neigh->dead) {
1253		NL_SET_ERR_MSG(extack, "Neighbor entry is now dead");
1254		new = old;
1255		goto out;
1256	}
1257	if (!(flags & NEIGH_UPDATE_F_ADMIN) &&
1258	    (old & (NUD_NOARP | NUD_PERMANENT)))
1259		goto out;
1260
1261	ext_learn_change = neigh_update_ext_learned(neigh, flags, &notify);
1262
1263	if (!(new & NUD_VALID)) {
1264		neigh_del_timer(neigh);
1265		if (old & NUD_CONNECTED)
1266			neigh_suspect(neigh);
1267		neigh->nud_state = new;
1268		err = 0;
1269		notify = old & NUD_VALID;
1270		if ((old & (NUD_INCOMPLETE | NUD_PROBE)) &&
1271		    (new & NUD_FAILED)) {
1272			neigh_invalidate(neigh);
1273			notify = 1;
1274		}
1275		goto out;
1276	}
1277
1278	/* Compare new lladdr with cached one */
1279	if (!dev->addr_len) {
1280		/* First case: device needs no address. */
1281		lladdr = neigh->ha;
1282	} else if (lladdr) {
1283		/* The second case: if something is already cached
1284		   and a new address is proposed:
1285		   - compare new & old
1286		   - if they are different, check override flag
1287		 */
1288		if ((old & NUD_VALID) &&
1289		    !memcmp(lladdr, neigh->ha, dev->addr_len))
1290			lladdr = neigh->ha;
1291	} else {
1292		/* No address is supplied; if we know something,
1293		   use it, otherwise discard the request.
1294		 */
1295		err = -EINVAL;
1296		if (!(old & NUD_VALID)) {
1297			NL_SET_ERR_MSG(extack, "No link layer address given");
1298			goto out;
1299		}
1300		lladdr = neigh->ha;
1301	}
1302
1303	/* Update confirmed timestamp for neighbour entry after we
1304	 * received ARP packet even if it doesn't change IP to MAC binding.
1305	 */
1306	if (new & NUD_CONNECTED)
1307		neigh->confirmed = jiffies;
 
1308
1309	/* If entry was valid and address is not changed,
1310	   do not change entry state, if new one is STALE.
1311	 */
1312	err = 0;
1313	update_isrouter = flags & NEIGH_UPDATE_F_OVERRIDE_ISROUTER;
1314	if (old & NUD_VALID) {
1315		if (lladdr != neigh->ha && !(flags & NEIGH_UPDATE_F_OVERRIDE)) {
1316			update_isrouter = 0;
1317			if ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) &&
1318			    (old & NUD_CONNECTED)) {
1319				lladdr = neigh->ha;
1320				new = NUD_STALE;
1321			} else
1322				goto out;
1323		} else {
1324			if (lladdr == neigh->ha && new == NUD_STALE &&
1325			    !(flags & NEIGH_UPDATE_F_ADMIN))
 
 
1326				new = old;
1327		}
1328	}
1329
1330	/* Update timestamp only once we know we will make a change to the
1331	 * neighbour entry. Otherwise we risk to move the locktime window with
1332	 * noop updates and ignore relevant ARP updates.
1333	 */
1334	if (new != old || lladdr != neigh->ha)
1335		neigh->updated = jiffies;
1336
1337	if (new != old) {
1338		neigh_del_timer(neigh);
1339		if (new & NUD_PROBE)
1340			atomic_set(&neigh->probes, 0);
1341		if (new & NUD_IN_TIMER)
1342			neigh_add_timer(neigh, (jiffies +
1343						((new & NUD_REACHABLE) ?
1344						 neigh->parms->reachable_time :
1345						 0)));
1346		neigh->nud_state = new;
1347		notify = 1;
1348	}
1349
1350	if (lladdr != neigh->ha) {
1351		write_seqlock(&neigh->ha_lock);
1352		memcpy(&neigh->ha, lladdr, dev->addr_len);
1353		write_sequnlock(&neigh->ha_lock);
1354		neigh_update_hhs(neigh);
1355		if (!(new & NUD_CONNECTED))
1356			neigh->confirmed = jiffies -
1357				      (NEIGH_VAR(neigh->parms, BASE_REACHABLE_TIME) << 1);
1358		notify = 1;
1359	}
1360	if (new == old)
1361		goto out;
1362	if (new & NUD_CONNECTED)
1363		neigh_connect(neigh);
1364	else
1365		neigh_suspect(neigh);
1366	if (!(old & NUD_VALID)) {
1367		struct sk_buff *skb;
1368
1369		/* Again: avoid dead loop if something went wrong */
1370
1371		while (neigh->nud_state & NUD_VALID &&
1372		       (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
1373			struct dst_entry *dst = skb_dst(skb);
1374			struct neighbour *n2, *n1 = neigh;
1375			write_unlock_bh(&neigh->lock);
1376
1377			rcu_read_lock();
1378
1379			/* Why not just use 'neigh' as-is?  The problem is that
1380			 * things such as shaper, eql, and sch_teql can end up
1381			 * using alternative, different, neigh objects to output
1382			 * the packet in the output path.  So what we need to do
1383			 * here is re-lookup the top-level neigh in the path so
1384			 * we can reinject the packet there.
1385			 */
1386			n2 = NULL;
1387			if (dst && dst->obsolete != DST_OBSOLETE_DEAD) {
1388				n2 = dst_neigh_lookup_skb(dst, skb);
1389				if (n2)
1390					n1 = n2;
1391			}
1392			n1->output(n1, skb);
1393			if (n2)
1394				neigh_release(n2);
1395			rcu_read_unlock();
1396
1397			write_lock_bh(&neigh->lock);
1398		}
1399		__skb_queue_purge(&neigh->arp_queue);
1400		neigh->arp_queue_len_bytes = 0;
1401	}
1402out:
1403	if (update_isrouter)
1404		neigh_update_is_router(neigh, flags, &notify);
 
 
 
1405	write_unlock_bh(&neigh->lock);
1406
1407	if (((new ^ old) & NUD_PERMANENT) || ext_learn_change)
1408		neigh_update_gc_list(neigh);
1409
1410	if (notify)
1411		neigh_update_notify(neigh, nlmsg_pid);
1412
1413	trace_neigh_update_done(neigh, err);
1414
1415	return err;
1416}
1417
1418int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
1419		 u32 flags, u32 nlmsg_pid)
1420{
1421	return __neigh_update(neigh, lladdr, new, flags, nlmsg_pid, NULL);
1422}
1423EXPORT_SYMBOL(neigh_update);
1424
1425/* Update the neigh to listen temporarily for probe responses, even if it is
1426 * in a NUD_FAILED state. The caller has to hold neigh->lock for writing.
1427 */
1428void __neigh_set_probe_once(struct neighbour *neigh)
1429{
1430	if (neigh->dead)
1431		return;
1432	neigh->updated = jiffies;
1433	if (!(neigh->nud_state & NUD_FAILED))
1434		return;
1435	neigh->nud_state = NUD_INCOMPLETE;
1436	atomic_set(&neigh->probes, neigh_max_probes(neigh));
1437	neigh_add_timer(neigh,
1438			jiffies + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),
1439				      HZ/100));
1440}
1441EXPORT_SYMBOL(__neigh_set_probe_once);
1442
1443struct neighbour *neigh_event_ns(struct neigh_table *tbl,
1444				 u8 *lladdr, void *saddr,
1445				 struct net_device *dev)
1446{
1447	struct neighbour *neigh = __neigh_lookup(tbl, saddr, dev,
1448						 lladdr || !dev->addr_len);
1449	if (neigh)
1450		neigh_update(neigh, lladdr, NUD_STALE,
1451			     NEIGH_UPDATE_F_OVERRIDE, 0);
1452	return neigh;
1453}
1454EXPORT_SYMBOL(neigh_event_ns);
1455
1456/* called with read_lock_bh(&n->lock); */
1457static void neigh_hh_init(struct neighbour *n)
1458{
1459	struct net_device *dev = n->dev;
1460	__be16 prot = n->tbl->protocol;
1461	struct hh_cache	*hh = &n->hh;
1462
1463	write_lock_bh(&n->lock);
1464
1465	/* Only one thread can come in here and initialize the
1466	 * hh_cache entry.
1467	 */
1468	if (!hh->hh_len)
1469		dev->header_ops->cache(n, hh, prot);
1470
1471	write_unlock_bh(&n->lock);
1472}
1473
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1474/* Slow and careful. */
1475
1476int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb)
1477{
 
1478	int rc = 0;
1479
 
 
 
 
 
1480	if (!neigh_event_send(neigh, skb)) {
1481		int err;
1482		struct net_device *dev = neigh->dev;
1483		unsigned int seq;
1484
1485		if (dev->header_ops->cache && !READ_ONCE(neigh->hh.hh_len))
1486			neigh_hh_init(neigh);
1487
1488		do {
1489			__skb_pull(skb, skb_network_offset(skb));
1490			seq = read_seqbegin(&neigh->ha_lock);
1491			err = dev_hard_header(skb, dev, ntohs(skb->protocol),
1492					      neigh->ha, NULL, skb->len);
1493		} while (read_seqretry(&neigh->ha_lock, seq));
1494
1495		if (err >= 0)
1496			rc = dev_queue_xmit(skb);
1497		else
1498			goto out_kfree_skb;
1499	}
1500out:
1501	return rc;
 
 
 
1502out_kfree_skb:
1503	rc = -EINVAL;
1504	kfree_skb(skb);
1505	goto out;
1506}
1507EXPORT_SYMBOL(neigh_resolve_output);
1508
1509/* As fast as possible without hh cache */
1510
1511int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb)
1512{
1513	struct net_device *dev = neigh->dev;
1514	unsigned int seq;
1515	int err;
1516
 
 
1517	do {
1518		__skb_pull(skb, skb_network_offset(skb));
1519		seq = read_seqbegin(&neigh->ha_lock);
1520		err = dev_hard_header(skb, dev, ntohs(skb->protocol),
1521				      neigh->ha, NULL, skb->len);
1522	} while (read_seqretry(&neigh->ha_lock, seq));
1523
1524	if (err >= 0)
1525		err = dev_queue_xmit(skb);
1526	else {
1527		err = -EINVAL;
1528		kfree_skb(skb);
1529	}
1530	return err;
1531}
1532EXPORT_SYMBOL(neigh_connected_output);
1533
1534int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb)
1535{
1536	return dev_queue_xmit(skb);
1537}
1538EXPORT_SYMBOL(neigh_direct_output);
1539
1540static void neigh_proxy_process(struct timer_list *t)
1541{
1542	struct neigh_table *tbl = from_timer(tbl, t, proxy_timer);
1543	long sched_next = 0;
1544	unsigned long now = jiffies;
1545	struct sk_buff *skb, *n;
1546
1547	spin_lock(&tbl->proxy_queue.lock);
1548
1549	skb_queue_walk_safe(&tbl->proxy_queue, skb, n) {
1550		long tdif = NEIGH_CB(skb)->sched_next - now;
1551
1552		if (tdif <= 0) {
1553			struct net_device *dev = skb->dev;
1554
1555			__skb_unlink(skb, &tbl->proxy_queue);
1556			if (tbl->proxy_redo && netif_running(dev)) {
1557				rcu_read_lock();
1558				tbl->proxy_redo(skb);
1559				rcu_read_unlock();
1560			} else {
1561				kfree_skb(skb);
1562			}
1563
1564			dev_put(dev);
1565		} else if (!sched_next || tdif < sched_next)
1566			sched_next = tdif;
1567	}
1568	del_timer(&tbl->proxy_timer);
1569	if (sched_next)
1570		mod_timer(&tbl->proxy_timer, jiffies + sched_next);
1571	spin_unlock(&tbl->proxy_queue.lock);
1572}
1573
1574void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
1575		    struct sk_buff *skb)
1576{
1577	unsigned long sched_next = jiffies +
1578			prandom_u32_max(NEIGH_VAR(p, PROXY_DELAY));
1579
1580	if (tbl->proxy_queue.qlen > NEIGH_VAR(p, PROXY_QLEN)) {
1581		kfree_skb(skb);
1582		return;
1583	}
1584
1585	NEIGH_CB(skb)->sched_next = sched_next;
1586	NEIGH_CB(skb)->flags |= LOCALLY_ENQUEUED;
1587
1588	spin_lock(&tbl->proxy_queue.lock);
1589	if (del_timer(&tbl->proxy_timer)) {
1590		if (time_before(tbl->proxy_timer.expires, sched_next))
1591			sched_next = tbl->proxy_timer.expires;
1592	}
1593	skb_dst_drop(skb);
1594	dev_hold(skb->dev);
1595	__skb_queue_tail(&tbl->proxy_queue, skb);
1596	mod_timer(&tbl->proxy_timer, sched_next);
1597	spin_unlock(&tbl->proxy_queue.lock);
1598}
1599EXPORT_SYMBOL(pneigh_enqueue);
1600
1601static inline struct neigh_parms *lookup_neigh_parms(struct neigh_table *tbl,
1602						      struct net *net, int ifindex)
1603{
1604	struct neigh_parms *p;
1605
1606	list_for_each_entry(p, &tbl->parms_list, list) {
1607		if ((p->dev && p->dev->ifindex == ifindex && net_eq(neigh_parms_net(p), net)) ||
1608		    (!p->dev && !ifindex && net_eq(net, &init_net)))
1609			return p;
1610	}
1611
1612	return NULL;
1613}
1614
1615struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
1616				      struct neigh_table *tbl)
1617{
1618	struct neigh_parms *p;
1619	struct net *net = dev_net(dev);
1620	const struct net_device_ops *ops = dev->netdev_ops;
1621
1622	p = kmemdup(&tbl->parms, sizeof(*p), GFP_KERNEL);
 
 
 
 
1623	if (p) {
1624		p->tbl		  = tbl;
1625		refcount_set(&p->refcnt, 1);
1626		p->reachable_time =
1627				neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
1628		dev_hold(dev);
1629		p->dev = dev;
1630		write_pnet(&p->net, net);
1631		p->sysctl_table = NULL;
1632
1633		if (ops->ndo_neigh_setup && ops->ndo_neigh_setup(dev, p)) {
1634			dev_put(dev);
1635			kfree(p);
1636			return NULL;
1637		}
1638
 
 
 
 
1639		write_lock_bh(&tbl->lock);
1640		list_add(&p->list, &tbl->parms.list);
 
1641		write_unlock_bh(&tbl->lock);
1642
1643		neigh_parms_data_state_cleanall(p);
1644	}
1645	return p;
1646}
1647EXPORT_SYMBOL(neigh_parms_alloc);
1648
1649static void neigh_rcu_free_parms(struct rcu_head *head)
1650{
1651	struct neigh_parms *parms =
1652		container_of(head, struct neigh_parms, rcu_head);
1653
1654	neigh_parms_put(parms);
1655}
1656
1657void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
1658{
 
 
1659	if (!parms || parms == &tbl->parms)
1660		return;
1661	write_lock_bh(&tbl->lock);
1662	list_del(&parms->list);
1663	parms->dead = 1;
 
 
 
 
 
 
 
 
 
1664	write_unlock_bh(&tbl->lock);
1665	if (parms->dev)
1666		dev_put(parms->dev);
1667	call_rcu(&parms->rcu_head, neigh_rcu_free_parms);
1668}
1669EXPORT_SYMBOL(neigh_parms_release);
1670
1671static void neigh_parms_destroy(struct neigh_parms *parms)
1672{
 
1673	kfree(parms);
1674}
1675
1676static struct lock_class_key neigh_table_proxy_queue_class;
1677
1678static struct neigh_table *neigh_tables[NEIGH_NR_TABLES] __read_mostly;
1679
1680void neigh_table_init(int index, struct neigh_table *tbl)
1681{
1682	unsigned long now = jiffies;
1683	unsigned long phsize;
1684
1685	INIT_LIST_HEAD(&tbl->parms_list);
1686	INIT_LIST_HEAD(&tbl->gc_list);
1687	list_add(&tbl->parms.list, &tbl->parms_list);
1688	write_pnet(&tbl->parms.net, &init_net);
1689	refcount_set(&tbl->parms.refcnt, 1);
1690	tbl->parms.reachable_time =
1691			  neigh_rand_reach_time(NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME));
1692
1693	tbl->stats = alloc_percpu(struct neigh_statistics);
1694	if (!tbl->stats)
1695		panic("cannot create neighbour cache statistics");
1696
1697#ifdef CONFIG_PROC_FS
1698	if (!proc_create_seq_data(tbl->id, 0, init_net.proc_net_stat,
1699			      &neigh_stat_seq_ops, tbl))
1700		panic("cannot create neighbour proc dir entry");
1701#endif
1702
1703	RCU_INIT_POINTER(tbl->nht, neigh_hash_alloc(3));
1704
1705	phsize = (PNEIGH_HASHMASK + 1) * sizeof(struct pneigh_entry *);
1706	tbl->phash_buckets = kzalloc(phsize, GFP_KERNEL);
1707
1708	if (!tbl->nht || !tbl->phash_buckets)
1709		panic("cannot allocate neighbour cache hashes");
1710
1711	if (!tbl->entry_size)
1712		tbl->entry_size = ALIGN(offsetof(struct neighbour, primary_key) +
1713					tbl->key_len, NEIGH_PRIV_ALIGN);
1714	else
1715		WARN_ON(tbl->entry_size % NEIGH_PRIV_ALIGN);
1716
1717	rwlock_init(&tbl->lock);
1718	INIT_DEFERRABLE_WORK(&tbl->gc_work, neigh_periodic_work);
1719	queue_delayed_work(system_power_efficient_wq, &tbl->gc_work,
1720			tbl->parms.reachable_time);
1721	timer_setup(&tbl->proxy_timer, neigh_proxy_process, 0);
1722	skb_queue_head_init_class(&tbl->proxy_queue,
1723			&neigh_table_proxy_queue_class);
1724
1725	tbl->last_flush = now;
1726	tbl->last_rand	= now + tbl->parms.reachable_time * 20;
 
 
 
 
 
1727
1728	neigh_tables[index] = tbl;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1729}
1730EXPORT_SYMBOL(neigh_table_init);
1731
1732int neigh_table_clear(int index, struct neigh_table *tbl)
1733{
1734	neigh_tables[index] = NULL;
 
1735	/* It is not clean... Fix it to unload IPv6 module safely */
1736	cancel_delayed_work_sync(&tbl->gc_work);
1737	del_timer_sync(&tbl->proxy_timer);
1738	pneigh_queue_purge(&tbl->proxy_queue);
1739	neigh_ifdown(tbl, NULL);
1740	if (atomic_read(&tbl->entries))
1741		pr_crit("neighbour leakage\n");
 
 
 
 
 
 
 
 
1742
1743	call_rcu(&rcu_dereference_protected(tbl->nht, 1)->rcu,
1744		 neigh_hash_free_rcu);
1745	tbl->nht = NULL;
1746
1747	kfree(tbl->phash_buckets);
1748	tbl->phash_buckets = NULL;
1749
1750	remove_proc_entry(tbl->id, init_net.proc_net_stat);
1751
1752	free_percpu(tbl->stats);
1753	tbl->stats = NULL;
1754
1755	return 0;
1756}
1757EXPORT_SYMBOL(neigh_table_clear);
1758
1759static struct neigh_table *neigh_find_table(int family)
1760{
1761	struct neigh_table *tbl = NULL;
1762
1763	switch (family) {
1764	case AF_INET:
1765		tbl = neigh_tables[NEIGH_ARP_TABLE];
1766		break;
1767	case AF_INET6:
1768		tbl = neigh_tables[NEIGH_ND_TABLE];
1769		break;
1770	case AF_DECnet:
1771		tbl = neigh_tables[NEIGH_DN_TABLE];
1772		break;
1773	}
1774
1775	return tbl;
1776}
1777
1778const struct nla_policy nda_policy[NDA_MAX+1] = {
1779	[NDA_UNSPEC]		= { .strict_start_type = NDA_NH_ID },
1780	[NDA_DST]		= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
1781	[NDA_LLADDR]		= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
1782	[NDA_CACHEINFO]		= { .len = sizeof(struct nda_cacheinfo) },
1783	[NDA_PROBES]		= { .type = NLA_U32 },
1784	[NDA_VLAN]		= { .type = NLA_U16 },
1785	[NDA_PORT]		= { .type = NLA_U16 },
1786	[NDA_VNI]		= { .type = NLA_U32 },
1787	[NDA_IFINDEX]		= { .type = NLA_U32 },
1788	[NDA_MASTER]		= { .type = NLA_U32 },
1789	[NDA_PROTOCOL]		= { .type = NLA_U8 },
1790	[NDA_NH_ID]		= { .type = NLA_U32 },
1791	[NDA_FDB_EXT_ATTRS]	= { .type = NLA_NESTED },
1792};
1793
1794static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh,
1795			struct netlink_ext_ack *extack)
1796{
1797	struct net *net = sock_net(skb->sk);
1798	struct ndmsg *ndm;
1799	struct nlattr *dst_attr;
1800	struct neigh_table *tbl;
1801	struct neighbour *neigh;
1802	struct net_device *dev = NULL;
1803	int err = -EINVAL;
1804
1805	ASSERT_RTNL();
1806	if (nlmsg_len(nlh) < sizeof(*ndm))
1807		goto out;
1808
1809	dst_attr = nlmsg_find_attr(nlh, sizeof(*ndm), NDA_DST);
1810	if (!dst_attr) {
1811		NL_SET_ERR_MSG(extack, "Network address not specified");
1812		goto out;
1813	}
1814
1815	ndm = nlmsg_data(nlh);
1816	if (ndm->ndm_ifindex) {
1817		dev = __dev_get_by_index(net, ndm->ndm_ifindex);
1818		if (dev == NULL) {
1819			err = -ENODEV;
1820			goto out;
1821		}
1822	}
1823
1824	tbl = neigh_find_table(ndm->ndm_family);
1825	if (tbl == NULL)
1826		return -EAFNOSUPPORT;
1827
1828	if (nla_len(dst_attr) < (int)tbl->key_len) {
1829		NL_SET_ERR_MSG(extack, "Invalid network address");
1830		goto out;
1831	}
1832
1833	if (ndm->ndm_flags & NTF_PROXY) {
1834		err = pneigh_delete(tbl, net, nla_data(dst_attr), dev);
1835		goto out;
1836	}
1837
1838	if (dev == NULL)
1839		goto out;
 
 
1840
1841	neigh = neigh_lookup(tbl, nla_data(dst_attr), dev);
1842	if (neigh == NULL) {
1843		err = -ENOENT;
 
 
 
 
 
 
 
 
 
 
1844		goto out;
1845	}
1846
1847	err = __neigh_update(neigh, NULL, NUD_FAILED,
1848			     NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN,
1849			     NETLINK_CB(skb).portid, extack);
1850	write_lock_bh(&tbl->lock);
1851	neigh_release(neigh);
1852	neigh_remove_one(neigh, tbl);
1853	write_unlock_bh(&tbl->lock);
1854
1855out:
1856	return err;
1857}
1858
1859static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh,
1860		     struct netlink_ext_ack *extack)
1861{
1862	int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE |
1863		NEIGH_UPDATE_F_OVERRIDE_ISROUTER;
1864	struct net *net = sock_net(skb->sk);
1865	struct ndmsg *ndm;
1866	struct nlattr *tb[NDA_MAX+1];
1867	struct neigh_table *tbl;
1868	struct net_device *dev = NULL;
1869	struct neighbour *neigh;
1870	void *dst, *lladdr;
1871	u8 protocol = 0;
1872	int err;
1873
1874	ASSERT_RTNL();
1875	err = nlmsg_parse_deprecated(nlh, sizeof(*ndm), tb, NDA_MAX,
1876				     nda_policy, extack);
1877	if (err < 0)
1878		goto out;
1879
1880	err = -EINVAL;
1881	if (!tb[NDA_DST]) {
1882		NL_SET_ERR_MSG(extack, "Network address not specified");
1883		goto out;
1884	}
1885
1886	ndm = nlmsg_data(nlh);
1887	if (ndm->ndm_ifindex) {
1888		dev = __dev_get_by_index(net, ndm->ndm_ifindex);
1889		if (dev == NULL) {
1890			err = -ENODEV;
1891			goto out;
1892		}
1893
1894		if (tb[NDA_LLADDR] && nla_len(tb[NDA_LLADDR]) < dev->addr_len) {
1895			NL_SET_ERR_MSG(extack, "Invalid link address");
1896			goto out;
1897		}
1898	}
1899
1900	tbl = neigh_find_table(ndm->ndm_family);
1901	if (tbl == NULL)
1902		return -EAFNOSUPPORT;
1903
1904	if (nla_len(tb[NDA_DST]) < (int)tbl->key_len) {
1905		NL_SET_ERR_MSG(extack, "Invalid network address");
1906		goto out;
1907	}
1908
1909	dst = nla_data(tb[NDA_DST]);
1910	lladdr = tb[NDA_LLADDR] ? nla_data(tb[NDA_LLADDR]) : NULL;
1911
1912	if (tb[NDA_PROTOCOL])
1913		protocol = nla_get_u8(tb[NDA_PROTOCOL]);
1914
1915	if (ndm->ndm_flags & NTF_PROXY) {
1916		struct pneigh_entry *pn;
1917
1918		err = -ENOBUFS;
1919		pn = pneigh_lookup(tbl, net, dst, dev, 1);
1920		if (pn) {
1921			pn->flags = ndm->ndm_flags;
1922			if (protocol)
1923				pn->protocol = protocol;
1924			err = 0;
1925		}
1926		goto out;
1927	}
1928
1929	if (!dev) {
1930		NL_SET_ERR_MSG(extack, "Device not specified");
1931		goto out;
1932	}
1933
1934	if (tbl->allow_add && !tbl->allow_add(dev, extack)) {
1935		err = -EINVAL;
1936		goto out;
1937	}
1938
1939	neigh = neigh_lookup(tbl, dst, dev);
1940	if (neigh == NULL) {
1941		bool exempt_from_gc;
1942
1943		if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
1944			err = -ENOENT;
 
 
 
 
1945			goto out;
1946		}
1947
1948		exempt_from_gc = ndm->ndm_state & NUD_PERMANENT ||
1949				 ndm->ndm_flags & NTF_EXT_LEARNED;
1950		neigh = ___neigh_create(tbl, dst, dev, exempt_from_gc, true);
1951		if (IS_ERR(neigh)) {
1952			err = PTR_ERR(neigh);
1953			goto out;
1954		}
1955	} else {
1956		if (nlh->nlmsg_flags & NLM_F_EXCL) {
1957			err = -EEXIST;
1958			neigh_release(neigh);
1959			goto out;
1960		}
1961
1962		if (!(nlh->nlmsg_flags & NLM_F_REPLACE))
1963			flags &= ~(NEIGH_UPDATE_F_OVERRIDE |
1964				   NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1965	}
1966
1967	if (protocol)
1968		neigh->protocol = protocol;
1969
1970	if (ndm->ndm_flags & NTF_EXT_LEARNED)
1971		flags |= NEIGH_UPDATE_F_EXT_LEARNED;
1972
1973	if (ndm->ndm_flags & NTF_ROUTER)
1974		flags |= NEIGH_UPDATE_F_ISROUTER;
 
 
 
 
 
 
 
 
 
1975
1976	if (ndm->ndm_flags & NTF_USE) {
1977		neigh_event_send(neigh, NULL);
1978		err = 0;
1979	} else
1980		err = __neigh_update(neigh, lladdr, ndm->ndm_state, flags,
1981				     NETLINK_CB(skb).portid, extack);
1982
1983	neigh_release(neigh);
 
 
 
 
 
 
 
1984
 
 
1985out:
1986	return err;
1987}
1988
1989static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms)
1990{
1991	struct nlattr *nest;
1992
1993	nest = nla_nest_start_noflag(skb, NDTA_PARMS);
1994	if (nest == NULL)
1995		return -ENOBUFS;
1996
1997	if ((parms->dev &&
1998	     nla_put_u32(skb, NDTPA_IFINDEX, parms->dev->ifindex)) ||
1999	    nla_put_u32(skb, NDTPA_REFCNT, refcount_read(&parms->refcnt)) ||
2000	    nla_put_u32(skb, NDTPA_QUEUE_LENBYTES,
2001			NEIGH_VAR(parms, QUEUE_LEN_BYTES)) ||
2002	    /* approximative value for deprecated QUEUE_LEN (in packets) */
2003	    nla_put_u32(skb, NDTPA_QUEUE_LEN,
2004			NEIGH_VAR(parms, QUEUE_LEN_BYTES) / SKB_TRUESIZE(ETH_FRAME_LEN)) ||
2005	    nla_put_u32(skb, NDTPA_PROXY_QLEN, NEIGH_VAR(parms, PROXY_QLEN)) ||
2006	    nla_put_u32(skb, NDTPA_APP_PROBES, NEIGH_VAR(parms, APP_PROBES)) ||
2007	    nla_put_u32(skb, NDTPA_UCAST_PROBES,
2008			NEIGH_VAR(parms, UCAST_PROBES)) ||
2009	    nla_put_u32(skb, NDTPA_MCAST_PROBES,
2010			NEIGH_VAR(parms, MCAST_PROBES)) ||
2011	    nla_put_u32(skb, NDTPA_MCAST_REPROBES,
2012			NEIGH_VAR(parms, MCAST_REPROBES)) ||
2013	    nla_put_msecs(skb, NDTPA_REACHABLE_TIME, parms->reachable_time,
2014			  NDTPA_PAD) ||
2015	    nla_put_msecs(skb, NDTPA_BASE_REACHABLE_TIME,
2016			  NEIGH_VAR(parms, BASE_REACHABLE_TIME), NDTPA_PAD) ||
2017	    nla_put_msecs(skb, NDTPA_GC_STALETIME,
2018			  NEIGH_VAR(parms, GC_STALETIME), NDTPA_PAD) ||
2019	    nla_put_msecs(skb, NDTPA_DELAY_PROBE_TIME,
2020			  NEIGH_VAR(parms, DELAY_PROBE_TIME), NDTPA_PAD) ||
2021	    nla_put_msecs(skb, NDTPA_RETRANS_TIME,
2022			  NEIGH_VAR(parms, RETRANS_TIME), NDTPA_PAD) ||
2023	    nla_put_msecs(skb, NDTPA_ANYCAST_DELAY,
2024			  NEIGH_VAR(parms, ANYCAST_DELAY), NDTPA_PAD) ||
2025	    nla_put_msecs(skb, NDTPA_PROXY_DELAY,
2026			  NEIGH_VAR(parms, PROXY_DELAY), NDTPA_PAD) ||
2027	    nla_put_msecs(skb, NDTPA_LOCKTIME,
2028			  NEIGH_VAR(parms, LOCKTIME), NDTPA_PAD))
2029		goto nla_put_failure;
2030	return nla_nest_end(skb, nest);
2031
2032nla_put_failure:
2033	nla_nest_cancel(skb, nest);
2034	return -EMSGSIZE;
2035}
2036
2037static int neightbl_fill_info(struct sk_buff *skb, struct neigh_table *tbl,
2038			      u32 pid, u32 seq, int type, int flags)
2039{
2040	struct nlmsghdr *nlh;
2041	struct ndtmsg *ndtmsg;
2042
2043	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
2044	if (nlh == NULL)
2045		return -EMSGSIZE;
2046
2047	ndtmsg = nlmsg_data(nlh);
2048
2049	read_lock_bh(&tbl->lock);
2050	ndtmsg->ndtm_family = tbl->family;
2051	ndtmsg->ndtm_pad1   = 0;
2052	ndtmsg->ndtm_pad2   = 0;
2053
2054	if (nla_put_string(skb, NDTA_NAME, tbl->id) ||
2055	    nla_put_msecs(skb, NDTA_GC_INTERVAL, tbl->gc_interval, NDTA_PAD) ||
2056	    nla_put_u32(skb, NDTA_THRESH1, tbl->gc_thresh1) ||
2057	    nla_put_u32(skb, NDTA_THRESH2, tbl->gc_thresh2) ||
2058	    nla_put_u32(skb, NDTA_THRESH3, tbl->gc_thresh3))
2059		goto nla_put_failure;
2060	{
2061		unsigned long now = jiffies;
2062		long flush_delta = now - tbl->last_flush;
2063		long rand_delta = now - tbl->last_rand;
2064		struct neigh_hash_table *nht;
2065		struct ndt_config ndc = {
2066			.ndtc_key_len		= tbl->key_len,
2067			.ndtc_entry_size	= tbl->entry_size,
2068			.ndtc_entries		= atomic_read(&tbl->entries),
2069			.ndtc_last_flush	= jiffies_to_msecs(flush_delta),
2070			.ndtc_last_rand		= jiffies_to_msecs(rand_delta),
2071			.ndtc_proxy_qlen	= tbl->proxy_queue.qlen,
2072		};
2073
2074		rcu_read_lock_bh();
2075		nht = rcu_dereference_bh(tbl->nht);
2076		ndc.ndtc_hash_rnd = nht->hash_rnd[0];
2077		ndc.ndtc_hash_mask = ((1 << nht->hash_shift) - 1);
2078		rcu_read_unlock_bh();
2079
2080		if (nla_put(skb, NDTA_CONFIG, sizeof(ndc), &ndc))
2081			goto nla_put_failure;
2082	}
2083
2084	{
2085		int cpu;
2086		struct ndt_stats ndst;
2087
2088		memset(&ndst, 0, sizeof(ndst));
2089
2090		for_each_possible_cpu(cpu) {
2091			struct neigh_statistics	*st;
2092
2093			st = per_cpu_ptr(tbl->stats, cpu);
2094			ndst.ndts_allocs		+= st->allocs;
2095			ndst.ndts_destroys		+= st->destroys;
2096			ndst.ndts_hash_grows		+= st->hash_grows;
2097			ndst.ndts_res_failed		+= st->res_failed;
2098			ndst.ndts_lookups		+= st->lookups;
2099			ndst.ndts_hits			+= st->hits;
2100			ndst.ndts_rcv_probes_mcast	+= st->rcv_probes_mcast;
2101			ndst.ndts_rcv_probes_ucast	+= st->rcv_probes_ucast;
2102			ndst.ndts_periodic_gc_runs	+= st->periodic_gc_runs;
2103			ndst.ndts_forced_gc_runs	+= st->forced_gc_runs;
2104			ndst.ndts_table_fulls		+= st->table_fulls;
2105		}
2106
2107		if (nla_put_64bit(skb, NDTA_STATS, sizeof(ndst), &ndst,
2108				  NDTA_PAD))
2109			goto nla_put_failure;
2110	}
2111
2112	BUG_ON(tbl->parms.dev);
2113	if (neightbl_fill_parms(skb, &tbl->parms) < 0)
2114		goto nla_put_failure;
2115
2116	read_unlock_bh(&tbl->lock);
2117	nlmsg_end(skb, nlh);
2118	return 0;
2119
2120nla_put_failure:
2121	read_unlock_bh(&tbl->lock);
2122	nlmsg_cancel(skb, nlh);
2123	return -EMSGSIZE;
2124}
2125
2126static int neightbl_fill_param_info(struct sk_buff *skb,
2127				    struct neigh_table *tbl,
2128				    struct neigh_parms *parms,
2129				    u32 pid, u32 seq, int type,
2130				    unsigned int flags)
2131{
2132	struct ndtmsg *ndtmsg;
2133	struct nlmsghdr *nlh;
2134
2135	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
2136	if (nlh == NULL)
2137		return -EMSGSIZE;
2138
2139	ndtmsg = nlmsg_data(nlh);
2140
2141	read_lock_bh(&tbl->lock);
2142	ndtmsg->ndtm_family = tbl->family;
2143	ndtmsg->ndtm_pad1   = 0;
2144	ndtmsg->ndtm_pad2   = 0;
2145
2146	if (nla_put_string(skb, NDTA_NAME, tbl->id) < 0 ||
2147	    neightbl_fill_parms(skb, parms) < 0)
2148		goto errout;
2149
2150	read_unlock_bh(&tbl->lock);
2151	nlmsg_end(skb, nlh);
2152	return 0;
2153errout:
2154	read_unlock_bh(&tbl->lock);
2155	nlmsg_cancel(skb, nlh);
2156	return -EMSGSIZE;
2157}
2158
2159static const struct nla_policy nl_neightbl_policy[NDTA_MAX+1] = {
2160	[NDTA_NAME]		= { .type = NLA_STRING },
2161	[NDTA_THRESH1]		= { .type = NLA_U32 },
2162	[NDTA_THRESH2]		= { .type = NLA_U32 },
2163	[NDTA_THRESH3]		= { .type = NLA_U32 },
2164	[NDTA_GC_INTERVAL]	= { .type = NLA_U64 },
2165	[NDTA_PARMS]		= { .type = NLA_NESTED },
2166};
2167
2168static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
2169	[NDTPA_IFINDEX]			= { .type = NLA_U32 },
2170	[NDTPA_QUEUE_LEN]		= { .type = NLA_U32 },
2171	[NDTPA_PROXY_QLEN]		= { .type = NLA_U32 },
2172	[NDTPA_APP_PROBES]		= { .type = NLA_U32 },
2173	[NDTPA_UCAST_PROBES]		= { .type = NLA_U32 },
2174	[NDTPA_MCAST_PROBES]		= { .type = NLA_U32 },
2175	[NDTPA_MCAST_REPROBES]		= { .type = NLA_U32 },
2176	[NDTPA_BASE_REACHABLE_TIME]	= { .type = NLA_U64 },
2177	[NDTPA_GC_STALETIME]		= { .type = NLA_U64 },
2178	[NDTPA_DELAY_PROBE_TIME]	= { .type = NLA_U64 },
2179	[NDTPA_RETRANS_TIME]		= { .type = NLA_U64 },
2180	[NDTPA_ANYCAST_DELAY]		= { .type = NLA_U64 },
2181	[NDTPA_PROXY_DELAY]		= { .type = NLA_U64 },
2182	[NDTPA_LOCKTIME]		= { .type = NLA_U64 },
2183};
2184
2185static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh,
2186			struct netlink_ext_ack *extack)
2187{
2188	struct net *net = sock_net(skb->sk);
2189	struct neigh_table *tbl;
2190	struct ndtmsg *ndtmsg;
2191	struct nlattr *tb[NDTA_MAX+1];
2192	bool found = false;
2193	int err, tidx;
2194
2195	err = nlmsg_parse_deprecated(nlh, sizeof(*ndtmsg), tb, NDTA_MAX,
2196				     nl_neightbl_policy, extack);
2197	if (err < 0)
2198		goto errout;
2199
2200	if (tb[NDTA_NAME] == NULL) {
2201		err = -EINVAL;
2202		goto errout;
2203	}
2204
2205	ndtmsg = nlmsg_data(nlh);
2206
2207	for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) {
2208		tbl = neigh_tables[tidx];
2209		if (!tbl)
2210			continue;
2211		if (ndtmsg->ndtm_family && tbl->family != ndtmsg->ndtm_family)
2212			continue;
2213		if (nla_strcmp(tb[NDTA_NAME], tbl->id) == 0) {
2214			found = true;
2215			break;
2216		}
2217	}
2218
2219	if (!found)
2220		return -ENOENT;
 
 
2221
2222	/*
2223	 * We acquire tbl->lock to be nice to the periodic timers and
2224	 * make sure they always see a consistent set of values.
2225	 */
2226	write_lock_bh(&tbl->lock);
2227
2228	if (tb[NDTA_PARMS]) {
2229		struct nlattr *tbp[NDTPA_MAX+1];
2230		struct neigh_parms *p;
2231		int i, ifindex = 0;
2232
2233		err = nla_parse_nested_deprecated(tbp, NDTPA_MAX,
2234						  tb[NDTA_PARMS],
2235						  nl_ntbl_parm_policy, extack);
2236		if (err < 0)
2237			goto errout_tbl_lock;
2238
2239		if (tbp[NDTPA_IFINDEX])
2240			ifindex = nla_get_u32(tbp[NDTPA_IFINDEX]);
2241
2242		p = lookup_neigh_parms(tbl, net, ifindex);
2243		if (p == NULL) {
2244			err = -ENOENT;
2245			goto errout_tbl_lock;
2246		}
2247
2248		for (i = 1; i <= NDTPA_MAX; i++) {
2249			if (tbp[i] == NULL)
2250				continue;
2251
2252			switch (i) {
2253			case NDTPA_QUEUE_LEN:
2254				NEIGH_VAR_SET(p, QUEUE_LEN_BYTES,
2255					      nla_get_u32(tbp[i]) *
2256					      SKB_TRUESIZE(ETH_FRAME_LEN));
2257				break;
2258			case NDTPA_QUEUE_LENBYTES:
2259				NEIGH_VAR_SET(p, QUEUE_LEN_BYTES,
2260					      nla_get_u32(tbp[i]));
2261				break;
2262			case NDTPA_PROXY_QLEN:
2263				NEIGH_VAR_SET(p, PROXY_QLEN,
2264					      nla_get_u32(tbp[i]));
2265				break;
2266			case NDTPA_APP_PROBES:
2267				NEIGH_VAR_SET(p, APP_PROBES,
2268					      nla_get_u32(tbp[i]));
2269				break;
2270			case NDTPA_UCAST_PROBES:
2271				NEIGH_VAR_SET(p, UCAST_PROBES,
2272					      nla_get_u32(tbp[i]));
2273				break;
2274			case NDTPA_MCAST_PROBES:
2275				NEIGH_VAR_SET(p, MCAST_PROBES,
2276					      nla_get_u32(tbp[i]));
2277				break;
2278			case NDTPA_MCAST_REPROBES:
2279				NEIGH_VAR_SET(p, MCAST_REPROBES,
2280					      nla_get_u32(tbp[i]));
2281				break;
2282			case NDTPA_BASE_REACHABLE_TIME:
2283				NEIGH_VAR_SET(p, BASE_REACHABLE_TIME,
2284					      nla_get_msecs(tbp[i]));
2285				/* update reachable_time as well, otherwise, the change will
2286				 * only be effective after the next time neigh_periodic_work
2287				 * decides to recompute it (can be multiple minutes)
2288				 */
2289				p->reachable_time =
2290					neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
2291				break;
2292			case NDTPA_GC_STALETIME:
2293				NEIGH_VAR_SET(p, GC_STALETIME,
2294					      nla_get_msecs(tbp[i]));
2295				break;
2296			case NDTPA_DELAY_PROBE_TIME:
2297				NEIGH_VAR_SET(p, DELAY_PROBE_TIME,
2298					      nla_get_msecs(tbp[i]));
2299				call_netevent_notifiers(NETEVENT_DELAY_PROBE_TIME_UPDATE, p);
2300				break;
2301			case NDTPA_RETRANS_TIME:
2302				NEIGH_VAR_SET(p, RETRANS_TIME,
2303					      nla_get_msecs(tbp[i]));
2304				break;
2305			case NDTPA_ANYCAST_DELAY:
2306				NEIGH_VAR_SET(p, ANYCAST_DELAY,
2307					      nla_get_msecs(tbp[i]));
2308				break;
2309			case NDTPA_PROXY_DELAY:
2310				NEIGH_VAR_SET(p, PROXY_DELAY,
2311					      nla_get_msecs(tbp[i]));
2312				break;
2313			case NDTPA_LOCKTIME:
2314				NEIGH_VAR_SET(p, LOCKTIME,
2315					      nla_get_msecs(tbp[i]));
2316				break;
2317			}
2318		}
2319	}
2320
2321	err = -ENOENT;
2322	if ((tb[NDTA_THRESH1] || tb[NDTA_THRESH2] ||
2323	     tb[NDTA_THRESH3] || tb[NDTA_GC_INTERVAL]) &&
2324	    !net_eq(net, &init_net))
2325		goto errout_tbl_lock;
2326
2327	if (tb[NDTA_THRESH1])
2328		tbl->gc_thresh1 = nla_get_u32(tb[NDTA_THRESH1]);
2329
2330	if (tb[NDTA_THRESH2])
2331		tbl->gc_thresh2 = nla_get_u32(tb[NDTA_THRESH2]);
2332
2333	if (tb[NDTA_THRESH3])
2334		tbl->gc_thresh3 = nla_get_u32(tb[NDTA_THRESH3]);
2335
2336	if (tb[NDTA_GC_INTERVAL])
2337		tbl->gc_interval = nla_get_msecs(tb[NDTA_GC_INTERVAL]);
2338
2339	err = 0;
2340
2341errout_tbl_lock:
2342	write_unlock_bh(&tbl->lock);
 
 
2343errout:
2344	return err;
2345}
2346
2347static int neightbl_valid_dump_info(const struct nlmsghdr *nlh,
2348				    struct netlink_ext_ack *extack)
2349{
2350	struct ndtmsg *ndtm;
2351
2352	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndtm))) {
2353		NL_SET_ERR_MSG(extack, "Invalid header for neighbor table dump request");
2354		return -EINVAL;
2355	}
2356
2357	ndtm = nlmsg_data(nlh);
2358	if (ndtm->ndtm_pad1  || ndtm->ndtm_pad2) {
2359		NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor table dump request");
2360		return -EINVAL;
2361	}
2362
2363	if (nlmsg_attrlen(nlh, sizeof(*ndtm))) {
2364		NL_SET_ERR_MSG(extack, "Invalid data after header in neighbor table dump request");
2365		return -EINVAL;
2366	}
2367
2368	return 0;
2369}
2370
2371static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2372{
2373	const struct nlmsghdr *nlh = cb->nlh;
2374	struct net *net = sock_net(skb->sk);
2375	int family, tidx, nidx = 0;
2376	int tbl_skip = cb->args[0];
2377	int neigh_skip = cb->args[1];
2378	struct neigh_table *tbl;
2379
2380	if (cb->strict_check) {
2381		int err = neightbl_valid_dump_info(nlh, cb->extack);
2382
2383		if (err < 0)
2384			return err;
2385	}
2386
2387	family = ((struct rtgenmsg *)nlmsg_data(nlh))->rtgen_family;
2388
2389	for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) {
2390		struct neigh_parms *p;
2391
2392		tbl = neigh_tables[tidx];
2393		if (!tbl)
2394			continue;
2395
2396		if (tidx < tbl_skip || (family && tbl->family != family))
2397			continue;
2398
2399		if (neightbl_fill_info(skb, tbl, NETLINK_CB(cb->skb).portid,
2400				       nlh->nlmsg_seq, RTM_NEWNEIGHTBL,
2401				       NLM_F_MULTI) < 0)
2402			break;
2403
2404		nidx = 0;
2405		p = list_next_entry(&tbl->parms, list);
2406		list_for_each_entry_from(p, &tbl->parms_list, list) {
2407			if (!net_eq(neigh_parms_net(p), net))
2408				continue;
2409
2410			if (nidx < neigh_skip)
2411				goto next;
2412
2413			if (neightbl_fill_param_info(skb, tbl, p,
2414						     NETLINK_CB(cb->skb).portid,
2415						     nlh->nlmsg_seq,
2416						     RTM_NEWNEIGHTBL,
2417						     NLM_F_MULTI) < 0)
2418				goto out;
2419		next:
2420			nidx++;
2421		}
2422
2423		neigh_skip = 0;
2424	}
2425out:
 
2426	cb->args[0] = tidx;
2427	cb->args[1] = nidx;
2428
2429	return skb->len;
2430}
2431
2432static int neigh_fill_info(struct sk_buff *skb, struct neighbour *neigh,
2433			   u32 pid, u32 seq, int type, unsigned int flags)
2434{
2435	unsigned long now = jiffies;
2436	struct nda_cacheinfo ci;
2437	struct nlmsghdr *nlh;
2438	struct ndmsg *ndm;
2439
2440	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
2441	if (nlh == NULL)
2442		return -EMSGSIZE;
2443
2444	ndm = nlmsg_data(nlh);
2445	ndm->ndm_family	 = neigh->ops->family;
2446	ndm->ndm_pad1    = 0;
2447	ndm->ndm_pad2    = 0;
2448	ndm->ndm_flags	 = neigh->flags;
2449	ndm->ndm_type	 = neigh->type;
2450	ndm->ndm_ifindex = neigh->dev->ifindex;
2451
2452	if (nla_put(skb, NDA_DST, neigh->tbl->key_len, neigh->primary_key))
2453		goto nla_put_failure;
2454
2455	read_lock_bh(&neigh->lock);
2456	ndm->ndm_state	 = neigh->nud_state;
2457	if (neigh->nud_state & NUD_VALID) {
2458		char haddr[MAX_ADDR_LEN];
2459
2460		neigh_ha_snapshot(haddr, neigh, neigh->dev);
2461		if (nla_put(skb, NDA_LLADDR, neigh->dev->addr_len, haddr) < 0) {
2462			read_unlock_bh(&neigh->lock);
2463			goto nla_put_failure;
2464		}
2465	}
2466
2467	ci.ndm_used	 = jiffies_to_clock_t(now - neigh->used);
2468	ci.ndm_confirmed = jiffies_to_clock_t(now - neigh->confirmed);
2469	ci.ndm_updated	 = jiffies_to_clock_t(now - neigh->updated);
2470	ci.ndm_refcnt	 = refcount_read(&neigh->refcnt) - 1;
2471	read_unlock_bh(&neigh->lock);
2472
2473	if (nla_put_u32(skb, NDA_PROBES, atomic_read(&neigh->probes)) ||
2474	    nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
2475		goto nla_put_failure;
2476
2477	if (neigh->protocol && nla_put_u8(skb, NDA_PROTOCOL, neigh->protocol))
2478		goto nla_put_failure;
2479
2480	nlmsg_end(skb, nlh);
2481	return 0;
2482
2483nla_put_failure:
2484	nlmsg_cancel(skb, nlh);
2485	return -EMSGSIZE;
2486}
2487
2488static int pneigh_fill_info(struct sk_buff *skb, struct pneigh_entry *pn,
2489			    u32 pid, u32 seq, int type, unsigned int flags,
2490			    struct neigh_table *tbl)
2491{
2492	struct nlmsghdr *nlh;
2493	struct ndmsg *ndm;
2494
2495	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
2496	if (nlh == NULL)
2497		return -EMSGSIZE;
2498
2499	ndm = nlmsg_data(nlh);
2500	ndm->ndm_family	 = tbl->family;
2501	ndm->ndm_pad1    = 0;
2502	ndm->ndm_pad2    = 0;
2503	ndm->ndm_flags	 = pn->flags | NTF_PROXY;
2504	ndm->ndm_type	 = RTN_UNICAST;
2505	ndm->ndm_ifindex = pn->dev ? pn->dev->ifindex : 0;
2506	ndm->ndm_state	 = NUD_NONE;
2507
2508	if (nla_put(skb, NDA_DST, tbl->key_len, pn->key))
2509		goto nla_put_failure;
2510
2511	if (pn->protocol && nla_put_u8(skb, NDA_PROTOCOL, pn->protocol))
2512		goto nla_put_failure;
2513
2514	nlmsg_end(skb, nlh);
2515	return 0;
2516
2517nla_put_failure:
2518	nlmsg_cancel(skb, nlh);
2519	return -EMSGSIZE;
2520}
2521
2522static void neigh_update_notify(struct neighbour *neigh, u32 nlmsg_pid)
2523{
2524	call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
2525	__neigh_notify(neigh, RTM_NEWNEIGH, 0, nlmsg_pid);
2526}
2527
2528static bool neigh_master_filtered(struct net_device *dev, int master_idx)
2529{
2530	struct net_device *master;
2531
2532	if (!master_idx)
2533		return false;
2534
2535	master = dev ? netdev_master_upper_dev_get(dev) : NULL;
2536	if (!master || master->ifindex != master_idx)
2537		return true;
2538
2539	return false;
2540}
2541
2542static bool neigh_ifindex_filtered(struct net_device *dev, int filter_idx)
2543{
2544	if (filter_idx && (!dev || dev->ifindex != filter_idx))
2545		return true;
2546
2547	return false;
2548}
2549
2550struct neigh_dump_filter {
2551	int master_idx;
2552	int dev_idx;
2553};
2554
2555static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
2556			    struct netlink_callback *cb,
2557			    struct neigh_dump_filter *filter)
2558{
2559	struct net *net = sock_net(skb->sk);
2560	struct neighbour *n;
2561	int rc, h, s_h = cb->args[1];
2562	int idx, s_idx = idx = cb->args[2];
2563	struct neigh_hash_table *nht;
2564	unsigned int flags = NLM_F_MULTI;
2565
2566	if (filter->dev_idx || filter->master_idx)
2567		flags |= NLM_F_DUMP_FILTERED;
2568
2569	rcu_read_lock_bh();
2570	nht = rcu_dereference_bh(tbl->nht);
2571
2572	for (h = s_h; h < (1 << nht->hash_shift); h++) {
2573		if (h > s_h)
2574			s_idx = 0;
2575		for (n = rcu_dereference_bh(nht->hash_buckets[h]), idx = 0;
2576		     n != NULL;
2577		     n = rcu_dereference_bh(n->next)) {
2578			if (idx < s_idx || !net_eq(dev_net(n->dev), net))
2579				goto next;
2580			if (neigh_ifindex_filtered(n->dev, filter->dev_idx) ||
2581			    neigh_master_filtered(n->dev, filter->master_idx))
2582				goto next;
2583			if (neigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,
2584					    cb->nlh->nlmsg_seq,
2585					    RTM_NEWNEIGH,
2586					    flags) < 0) {
2587				rc = -1;
2588				goto out;
2589			}
2590next:
2591			idx++;
2592		}
2593	}
2594	rc = skb->len;
2595out:
2596	rcu_read_unlock_bh();
2597	cb->args[1] = h;
2598	cb->args[2] = idx;
2599	return rc;
2600}
2601
2602static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
2603			     struct netlink_callback *cb,
2604			     struct neigh_dump_filter *filter)
2605{
2606	struct pneigh_entry *n;
2607	struct net *net = sock_net(skb->sk);
2608	int rc, h, s_h = cb->args[3];
2609	int idx, s_idx = idx = cb->args[4];
2610	unsigned int flags = NLM_F_MULTI;
2611
2612	if (filter->dev_idx || filter->master_idx)
2613		flags |= NLM_F_DUMP_FILTERED;
2614
2615	read_lock_bh(&tbl->lock);
2616
2617	for (h = s_h; h <= PNEIGH_HASHMASK; h++) {
2618		if (h > s_h)
2619			s_idx = 0;
2620		for (n = tbl->phash_buckets[h], idx = 0; n; n = n->next) {
2621			if (idx < s_idx || pneigh_net(n) != net)
2622				goto next;
2623			if (neigh_ifindex_filtered(n->dev, filter->dev_idx) ||
2624			    neigh_master_filtered(n->dev, filter->master_idx))
2625				goto next;
2626			if (pneigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid,
2627					    cb->nlh->nlmsg_seq,
2628					    RTM_NEWNEIGH, flags, tbl) < 0) {
 
2629				read_unlock_bh(&tbl->lock);
2630				rc = -1;
2631				goto out;
2632			}
2633		next:
2634			idx++;
2635		}
2636	}
2637
2638	read_unlock_bh(&tbl->lock);
2639	rc = skb->len;
2640out:
2641	cb->args[3] = h;
2642	cb->args[4] = idx;
2643	return rc;
2644
2645}
2646
2647static int neigh_valid_dump_req(const struct nlmsghdr *nlh,
2648				bool strict_check,
2649				struct neigh_dump_filter *filter,
2650				struct netlink_ext_ack *extack)
2651{
2652	struct nlattr *tb[NDA_MAX + 1];
2653	int err, i;
2654
2655	if (strict_check) {
2656		struct ndmsg *ndm;
2657
2658		if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndm))) {
2659			NL_SET_ERR_MSG(extack, "Invalid header for neighbor dump request");
2660			return -EINVAL;
2661		}
2662
2663		ndm = nlmsg_data(nlh);
2664		if (ndm->ndm_pad1  || ndm->ndm_pad2  || ndm->ndm_ifindex ||
2665		    ndm->ndm_state || ndm->ndm_type) {
2666			NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor dump request");
2667			return -EINVAL;
2668		}
2669
2670		if (ndm->ndm_flags & ~NTF_PROXY) {
2671			NL_SET_ERR_MSG(extack, "Invalid flags in header for neighbor dump request");
2672			return -EINVAL;
2673		}
2674
2675		err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct ndmsg),
2676						    tb, NDA_MAX, nda_policy,
2677						    extack);
2678	} else {
2679		err = nlmsg_parse_deprecated(nlh, sizeof(struct ndmsg), tb,
2680					     NDA_MAX, nda_policy, extack);
2681	}
2682	if (err < 0)
2683		return err;
2684
2685	for (i = 0; i <= NDA_MAX; ++i) {
2686		if (!tb[i])
2687			continue;
2688
2689		/* all new attributes should require strict_check */
2690		switch (i) {
2691		case NDA_IFINDEX:
2692			filter->dev_idx = nla_get_u32(tb[i]);
2693			break;
2694		case NDA_MASTER:
2695			filter->master_idx = nla_get_u32(tb[i]);
2696			break;
2697		default:
2698			if (strict_check) {
2699				NL_SET_ERR_MSG(extack, "Unsupported attribute in neighbor dump request");
2700				return -EINVAL;
2701			}
2702		}
2703	}
2704
2705	return 0;
2706}
2707
2708static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2709{
2710	const struct nlmsghdr *nlh = cb->nlh;
2711	struct neigh_dump_filter filter = {};
2712	struct neigh_table *tbl;
2713	int t, family, s_t;
2714	int proxy = 0;
2715	int err;
2716
2717	family = ((struct rtgenmsg *)nlmsg_data(nlh))->rtgen_family;
 
2718
2719	/* check for full ndmsg structure presence, family member is
2720	 * the same for both structures
2721	 */
2722	if (nlmsg_len(nlh) >= sizeof(struct ndmsg) &&
2723	    ((struct ndmsg *)nlmsg_data(nlh))->ndm_flags == NTF_PROXY)
2724		proxy = 1;
2725
2726	err = neigh_valid_dump_req(nlh, cb->strict_check, &filter, cb->extack);
2727	if (err < 0 && cb->strict_check)
2728		return err;
2729
2730	s_t = cb->args[0];
2731
2732	for (t = 0; t < NEIGH_NR_TABLES; t++) {
2733		tbl = neigh_tables[t];
2734
2735		if (!tbl)
2736			continue;
2737		if (t < s_t || (family && tbl->family != family))
2738			continue;
2739		if (t > s_t)
2740			memset(&cb->args[1], 0, sizeof(cb->args) -
2741						sizeof(cb->args[0]));
2742		if (proxy)
2743			err = pneigh_dump_table(tbl, skb, cb, &filter);
2744		else
2745			err = neigh_dump_table(tbl, skb, cb, &filter);
2746		if (err < 0)
2747			break;
2748	}
 
2749
2750	cb->args[0] = t;
2751	return skb->len;
2752}
2753
2754static int neigh_valid_get_req(const struct nlmsghdr *nlh,
2755			       struct neigh_table **tbl,
2756			       void **dst, int *dev_idx, u8 *ndm_flags,
2757			       struct netlink_ext_ack *extack)
2758{
2759	struct nlattr *tb[NDA_MAX + 1];
2760	struct ndmsg *ndm;
2761	int err, i;
2762
2763	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndm))) {
2764		NL_SET_ERR_MSG(extack, "Invalid header for neighbor get request");
2765		return -EINVAL;
2766	}
2767
2768	ndm = nlmsg_data(nlh);
2769	if (ndm->ndm_pad1  || ndm->ndm_pad2  || ndm->ndm_state ||
2770	    ndm->ndm_type) {
2771		NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor get request");
2772		return -EINVAL;
2773	}
2774
2775	if (ndm->ndm_flags & ~NTF_PROXY) {
2776		NL_SET_ERR_MSG(extack, "Invalid flags in header for neighbor get request");
2777		return -EINVAL;
2778	}
2779
2780	err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct ndmsg), tb,
2781					    NDA_MAX, nda_policy, extack);
2782	if (err < 0)
2783		return err;
2784
2785	*ndm_flags = ndm->ndm_flags;
2786	*dev_idx = ndm->ndm_ifindex;
2787	*tbl = neigh_find_table(ndm->ndm_family);
2788	if (*tbl == NULL) {
2789		NL_SET_ERR_MSG(extack, "Unsupported family in header for neighbor get request");
2790		return -EAFNOSUPPORT;
2791	}
2792
2793	for (i = 0; i <= NDA_MAX; ++i) {
2794		if (!tb[i])
2795			continue;
2796
2797		switch (i) {
2798		case NDA_DST:
2799			if (nla_len(tb[i]) != (int)(*tbl)->key_len) {
2800				NL_SET_ERR_MSG(extack, "Invalid network address in neighbor get request");
2801				return -EINVAL;
2802			}
2803			*dst = nla_data(tb[i]);
2804			break;
2805		default:
2806			NL_SET_ERR_MSG(extack, "Unsupported attribute in neighbor get request");
2807			return -EINVAL;
2808		}
2809	}
2810
2811	return 0;
2812}
2813
2814static inline size_t neigh_nlmsg_size(void)
2815{
2816	return NLMSG_ALIGN(sizeof(struct ndmsg))
2817	       + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
2818	       + nla_total_size(MAX_ADDR_LEN) /* NDA_LLADDR */
2819	       + nla_total_size(sizeof(struct nda_cacheinfo))
2820	       + nla_total_size(4)  /* NDA_PROBES */
2821	       + nla_total_size(1); /* NDA_PROTOCOL */
2822}
2823
2824static int neigh_get_reply(struct net *net, struct neighbour *neigh,
2825			   u32 pid, u32 seq)
2826{
2827	struct sk_buff *skb;
2828	int err = 0;
2829
2830	skb = nlmsg_new(neigh_nlmsg_size(), GFP_KERNEL);
2831	if (!skb)
2832		return -ENOBUFS;
2833
2834	err = neigh_fill_info(skb, neigh, pid, seq, RTM_NEWNEIGH, 0);
2835	if (err) {
2836		kfree_skb(skb);
2837		goto errout;
2838	}
2839
2840	err = rtnl_unicast(skb, net, pid);
2841errout:
2842	return err;
2843}
2844
2845static inline size_t pneigh_nlmsg_size(void)
2846{
2847	return NLMSG_ALIGN(sizeof(struct ndmsg))
2848	       + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
2849	       + nla_total_size(1); /* NDA_PROTOCOL */
2850}
2851
2852static int pneigh_get_reply(struct net *net, struct pneigh_entry *neigh,
2853			    u32 pid, u32 seq, struct neigh_table *tbl)
2854{
2855	struct sk_buff *skb;
2856	int err = 0;
2857
2858	skb = nlmsg_new(pneigh_nlmsg_size(), GFP_KERNEL);
2859	if (!skb)
2860		return -ENOBUFS;
2861
2862	err = pneigh_fill_info(skb, neigh, pid, seq, RTM_NEWNEIGH, 0, tbl);
2863	if (err) {
2864		kfree_skb(skb);
2865		goto errout;
2866	}
2867
2868	err = rtnl_unicast(skb, net, pid);
2869errout:
2870	return err;
2871}
2872
2873static int neigh_get(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2874		     struct netlink_ext_ack *extack)
2875{
2876	struct net *net = sock_net(in_skb->sk);
2877	struct net_device *dev = NULL;
2878	struct neigh_table *tbl = NULL;
2879	struct neighbour *neigh;
2880	void *dst = NULL;
2881	u8 ndm_flags = 0;
2882	int dev_idx = 0;
2883	int err;
2884
2885	err = neigh_valid_get_req(nlh, &tbl, &dst, &dev_idx, &ndm_flags,
2886				  extack);
2887	if (err < 0)
2888		return err;
2889
2890	if (dev_idx) {
2891		dev = __dev_get_by_index(net, dev_idx);
2892		if (!dev) {
2893			NL_SET_ERR_MSG(extack, "Unknown device ifindex");
2894			return -ENODEV;
2895		}
2896	}
2897
2898	if (!dst) {
2899		NL_SET_ERR_MSG(extack, "Network address not specified");
2900		return -EINVAL;
2901	}
2902
2903	if (ndm_flags & NTF_PROXY) {
2904		struct pneigh_entry *pn;
2905
2906		pn = pneigh_lookup(tbl, net, dst, dev, 0);
2907		if (!pn) {
2908			NL_SET_ERR_MSG(extack, "Proxy neighbour entry not found");
2909			return -ENOENT;
2910		}
2911		return pneigh_get_reply(net, pn, NETLINK_CB(in_skb).portid,
2912					nlh->nlmsg_seq, tbl);
2913	}
2914
2915	if (!dev) {
2916		NL_SET_ERR_MSG(extack, "No device specified");
2917		return -EINVAL;
2918	}
2919
2920	neigh = neigh_lookup(tbl, dst, dev);
2921	if (!neigh) {
2922		NL_SET_ERR_MSG(extack, "Neighbour entry not found");
2923		return -ENOENT;
2924	}
2925
2926	err = neigh_get_reply(net, neigh, NETLINK_CB(in_skb).portid,
2927			      nlh->nlmsg_seq);
2928
2929	neigh_release(neigh);
2930
2931	return err;
2932}
2933
2934void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie)
2935{
2936	int chain;
2937	struct neigh_hash_table *nht;
2938
2939	rcu_read_lock_bh();
2940	nht = rcu_dereference_bh(tbl->nht);
2941
2942	read_lock(&tbl->lock); /* avoid resizes */
2943	for (chain = 0; chain < (1 << nht->hash_shift); chain++) {
2944		struct neighbour *n;
2945
2946		for (n = rcu_dereference_bh(nht->hash_buckets[chain]);
2947		     n != NULL;
2948		     n = rcu_dereference_bh(n->next))
2949			cb(n, cookie);
2950	}
2951	read_unlock(&tbl->lock);
2952	rcu_read_unlock_bh();
2953}
2954EXPORT_SYMBOL(neigh_for_each);
2955
2956/* The tbl->lock must be held as a writer and BH disabled. */
2957void __neigh_for_each_release(struct neigh_table *tbl,
2958			      int (*cb)(struct neighbour *))
2959{
2960	int chain;
2961	struct neigh_hash_table *nht;
2962
2963	nht = rcu_dereference_protected(tbl->nht,
2964					lockdep_is_held(&tbl->lock));
2965	for (chain = 0; chain < (1 << nht->hash_shift); chain++) {
2966		struct neighbour *n;
2967		struct neighbour __rcu **np;
2968
2969		np = &nht->hash_buckets[chain];
2970		while ((n = rcu_dereference_protected(*np,
2971					lockdep_is_held(&tbl->lock))) != NULL) {
2972			int release;
2973
2974			write_lock(&n->lock);
2975			release = cb(n);
2976			if (release) {
2977				rcu_assign_pointer(*np,
2978					rcu_dereference_protected(n->next,
2979						lockdep_is_held(&tbl->lock)));
2980				neigh_mark_dead(n);
2981			} else
2982				np = &n->next;
2983			write_unlock(&n->lock);
2984			if (release)
2985				neigh_cleanup_and_release(n);
2986		}
2987	}
2988}
2989EXPORT_SYMBOL(__neigh_for_each_release);
2990
2991int neigh_xmit(int index, struct net_device *dev,
2992	       const void *addr, struct sk_buff *skb)
2993{
2994	int err = -EAFNOSUPPORT;
2995	if (likely(index < NEIGH_NR_TABLES)) {
2996		struct neigh_table *tbl;
2997		struct neighbour *neigh;
2998
2999		tbl = neigh_tables[index];
3000		if (!tbl)
3001			goto out;
3002		rcu_read_lock_bh();
3003		if (index == NEIGH_ARP_TABLE) {
3004			u32 key = *((u32 *)addr);
3005
3006			neigh = __ipv4_neigh_lookup_noref(dev, key);
3007		} else {
3008			neigh = __neigh_lookup_noref(tbl, addr, dev);
3009		}
3010		if (!neigh)
3011			neigh = __neigh_create(tbl, addr, dev, false);
3012		err = PTR_ERR(neigh);
3013		if (IS_ERR(neigh)) {
3014			rcu_read_unlock_bh();
3015			goto out_kfree_skb;
3016		}
3017		err = neigh->output(neigh, skb);
3018		rcu_read_unlock_bh();
3019	}
3020	else if (index == NEIGH_LINK_TABLE) {
3021		err = dev_hard_header(skb, dev, ntohs(skb->protocol),
3022				      addr, NULL, skb->len);
3023		if (err < 0)
3024			goto out_kfree_skb;
3025		err = dev_queue_xmit(skb);
3026	}
3027out:
3028	return err;
3029out_kfree_skb:
3030	kfree_skb(skb);
3031	goto out;
3032}
3033EXPORT_SYMBOL(neigh_xmit);
3034
3035#ifdef CONFIG_PROC_FS
3036
3037static struct neighbour *neigh_get_first(struct seq_file *seq)
3038{
3039	struct neigh_seq_state *state = seq->private;
3040	struct net *net = seq_file_net(seq);
3041	struct neigh_hash_table *nht = state->nht;
3042	struct neighbour *n = NULL;
3043	int bucket;
3044
3045	state->flags &= ~NEIGH_SEQ_IS_PNEIGH;
3046	for (bucket = 0; bucket < (1 << nht->hash_shift); bucket++) {
3047		n = rcu_dereference_bh(nht->hash_buckets[bucket]);
3048
3049		while (n) {
3050			if (!net_eq(dev_net(n->dev), net))
3051				goto next;
3052			if (state->neigh_sub_iter) {
3053				loff_t fakep = 0;
3054				void *v;
3055
3056				v = state->neigh_sub_iter(state, n, &fakep);
3057				if (!v)
3058					goto next;
3059			}
3060			if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
3061				break;
3062			if (n->nud_state & ~NUD_NOARP)
3063				break;
3064next:
3065			n = rcu_dereference_bh(n->next);
3066		}
3067
3068		if (n)
3069			break;
3070	}
3071	state->bucket = bucket;
3072
3073	return n;
3074}
3075
3076static struct neighbour *neigh_get_next(struct seq_file *seq,
3077					struct neighbour *n,
3078					loff_t *pos)
3079{
3080	struct neigh_seq_state *state = seq->private;
3081	struct net *net = seq_file_net(seq);
3082	struct neigh_hash_table *nht = state->nht;
3083
3084	if (state->neigh_sub_iter) {
3085		void *v = state->neigh_sub_iter(state, n, pos);
3086		if (v)
3087			return n;
3088	}
3089	n = rcu_dereference_bh(n->next);
3090
3091	while (1) {
3092		while (n) {
3093			if (!net_eq(dev_net(n->dev), net))
3094				goto next;
3095			if (state->neigh_sub_iter) {
3096				void *v = state->neigh_sub_iter(state, n, pos);
3097				if (v)
3098					return n;
3099				goto next;
3100			}
3101			if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
3102				break;
3103
3104			if (n->nud_state & ~NUD_NOARP)
3105				break;
3106next:
3107			n = rcu_dereference_bh(n->next);
3108		}
3109
3110		if (n)
3111			break;
3112
3113		if (++state->bucket >= (1 << nht->hash_shift))
3114			break;
3115
3116		n = rcu_dereference_bh(nht->hash_buckets[state->bucket]);
3117	}
3118
3119	if (n && pos)
3120		--(*pos);
3121	return n;
3122}
3123
3124static struct neighbour *neigh_get_idx(struct seq_file *seq, loff_t *pos)
3125{
3126	struct neighbour *n = neigh_get_first(seq);
3127
3128	if (n) {
3129		--(*pos);
3130		while (*pos) {
3131			n = neigh_get_next(seq, n, pos);
3132			if (!n)
3133				break;
3134		}
3135	}
3136	return *pos ? NULL : n;
3137}
3138
3139static struct pneigh_entry *pneigh_get_first(struct seq_file *seq)
3140{
3141	struct neigh_seq_state *state = seq->private;
3142	struct net *net = seq_file_net(seq);
3143	struct neigh_table *tbl = state->tbl;
3144	struct pneigh_entry *pn = NULL;
3145	int bucket;
3146
3147	state->flags |= NEIGH_SEQ_IS_PNEIGH;
3148	for (bucket = 0; bucket <= PNEIGH_HASHMASK; bucket++) {
3149		pn = tbl->phash_buckets[bucket];
3150		while (pn && !net_eq(pneigh_net(pn), net))
3151			pn = pn->next;
3152		if (pn)
3153			break;
3154	}
3155	state->bucket = bucket;
3156
3157	return pn;
3158}
3159
3160static struct pneigh_entry *pneigh_get_next(struct seq_file *seq,
3161					    struct pneigh_entry *pn,
3162					    loff_t *pos)
3163{
3164	struct neigh_seq_state *state = seq->private;
3165	struct net *net = seq_file_net(seq);
3166	struct neigh_table *tbl = state->tbl;
3167
3168	do {
3169		pn = pn->next;
3170	} while (pn && !net_eq(pneigh_net(pn), net));
3171
3172	while (!pn) {
3173		if (++state->bucket > PNEIGH_HASHMASK)
3174			break;
3175		pn = tbl->phash_buckets[state->bucket];
3176		while (pn && !net_eq(pneigh_net(pn), net))
3177			pn = pn->next;
3178		if (pn)
3179			break;
3180	}
3181
3182	if (pn && pos)
3183		--(*pos);
3184
3185	return pn;
3186}
3187
3188static struct pneigh_entry *pneigh_get_idx(struct seq_file *seq, loff_t *pos)
3189{
3190	struct pneigh_entry *pn = pneigh_get_first(seq);
3191
3192	if (pn) {
3193		--(*pos);
3194		while (*pos) {
3195			pn = pneigh_get_next(seq, pn, pos);
3196			if (!pn)
3197				break;
3198		}
3199	}
3200	return *pos ? NULL : pn;
3201}
3202
3203static void *neigh_get_idx_any(struct seq_file *seq, loff_t *pos)
3204{
3205	struct neigh_seq_state *state = seq->private;
3206	void *rc;
3207	loff_t idxpos = *pos;
3208
3209	rc = neigh_get_idx(seq, &idxpos);
3210	if (!rc && !(state->flags & NEIGH_SEQ_NEIGH_ONLY))
3211		rc = pneigh_get_idx(seq, &idxpos);
3212
3213	return rc;
3214}
3215
3216void *neigh_seq_start(struct seq_file *seq, loff_t *pos, struct neigh_table *tbl, unsigned int neigh_seq_flags)
3217	__acquires(tbl->lock)
3218	__acquires(rcu_bh)
3219{
3220	struct neigh_seq_state *state = seq->private;
3221
3222	state->tbl = tbl;
3223	state->bucket = 0;
3224	state->flags = (neigh_seq_flags & ~NEIGH_SEQ_IS_PNEIGH);
3225
3226	rcu_read_lock_bh();
3227	state->nht = rcu_dereference_bh(tbl->nht);
3228	read_lock(&tbl->lock);
3229
3230	return *pos ? neigh_get_idx_any(seq, pos) : SEQ_START_TOKEN;
3231}
3232EXPORT_SYMBOL(neigh_seq_start);
3233
3234void *neigh_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3235{
3236	struct neigh_seq_state *state;
3237	void *rc;
3238
3239	if (v == SEQ_START_TOKEN) {
3240		rc = neigh_get_first(seq);
3241		goto out;
3242	}
3243
3244	state = seq->private;
3245	if (!(state->flags & NEIGH_SEQ_IS_PNEIGH)) {
3246		rc = neigh_get_next(seq, v, NULL);
3247		if (rc)
3248			goto out;
3249		if (!(state->flags & NEIGH_SEQ_NEIGH_ONLY))
3250			rc = pneigh_get_first(seq);
3251	} else {
3252		BUG_ON(state->flags & NEIGH_SEQ_NEIGH_ONLY);
3253		rc = pneigh_get_next(seq, v, NULL);
3254	}
3255out:
3256	++(*pos);
3257	return rc;
3258}
3259EXPORT_SYMBOL(neigh_seq_next);
3260
3261void neigh_seq_stop(struct seq_file *seq, void *v)
3262	__releases(tbl->lock)
3263	__releases(rcu_bh)
3264{
3265	struct neigh_seq_state *state = seq->private;
3266	struct neigh_table *tbl = state->tbl;
3267
3268	read_unlock(&tbl->lock);
3269	rcu_read_unlock_bh();
3270}
3271EXPORT_SYMBOL(neigh_seq_stop);
3272
3273/* statistics via seq_file */
3274
3275static void *neigh_stat_seq_start(struct seq_file *seq, loff_t *pos)
3276{
3277	struct neigh_table *tbl = PDE_DATA(file_inode(seq->file));
3278	int cpu;
3279
3280	if (*pos == 0)
3281		return SEQ_START_TOKEN;
3282
3283	for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
3284		if (!cpu_possible(cpu))
3285			continue;
3286		*pos = cpu+1;
3287		return per_cpu_ptr(tbl->stats, cpu);
3288	}
3289	return NULL;
3290}
3291
3292static void *neigh_stat_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3293{
3294	struct neigh_table *tbl = PDE_DATA(file_inode(seq->file));
3295	int cpu;
3296
3297	for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
3298		if (!cpu_possible(cpu))
3299			continue;
3300		*pos = cpu+1;
3301		return per_cpu_ptr(tbl->stats, cpu);
3302	}
3303	(*pos)++;
3304	return NULL;
3305}
3306
3307static void neigh_stat_seq_stop(struct seq_file *seq, void *v)
3308{
3309
3310}
3311
3312static int neigh_stat_seq_show(struct seq_file *seq, void *v)
3313{
3314	struct neigh_table *tbl = PDE_DATA(file_inode(seq->file));
3315	struct neigh_statistics *st = v;
3316
3317	if (v == SEQ_START_TOKEN) {
3318		seq_printf(seq, "entries  allocs destroys hash_grows  lookups hits  res_failed  rcv_probes_mcast rcv_probes_ucast  periodic_gc_runs forced_gc_runs unresolved_discards table_fulls\n");
3319		return 0;
3320	}
3321
3322	seq_printf(seq, "%08x  %08lx %08lx %08lx  %08lx %08lx  %08lx  "
3323			"%08lx %08lx  %08lx %08lx %08lx %08lx\n",
3324		   atomic_read(&tbl->entries),
3325
3326		   st->allocs,
3327		   st->destroys,
3328		   st->hash_grows,
3329
3330		   st->lookups,
3331		   st->hits,
3332
3333		   st->res_failed,
3334
3335		   st->rcv_probes_mcast,
3336		   st->rcv_probes_ucast,
3337
3338		   st->periodic_gc_runs,
3339		   st->forced_gc_runs,
3340		   st->unres_discards,
3341		   st->table_fulls
3342		   );
3343
3344	return 0;
3345}
3346
3347static const struct seq_operations neigh_stat_seq_ops = {
3348	.start	= neigh_stat_seq_start,
3349	.next	= neigh_stat_seq_next,
3350	.stop	= neigh_stat_seq_stop,
3351	.show	= neigh_stat_seq_show,
3352};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3353#endif /* CONFIG_PROC_FS */
3354
3355static void __neigh_notify(struct neighbour *n, int type, int flags,
3356			   u32 pid)
 
 
 
 
 
 
 
 
3357{
3358	struct net *net = dev_net(n->dev);
3359	struct sk_buff *skb;
3360	int err = -ENOBUFS;
3361
3362	skb = nlmsg_new(neigh_nlmsg_size(), GFP_ATOMIC);
3363	if (skb == NULL)
3364		goto errout;
3365
3366	err = neigh_fill_info(skb, n, pid, 0, type, flags);
3367	if (err < 0) {
3368		/* -EMSGSIZE implies BUG in neigh_nlmsg_size() */
3369		WARN_ON(err == -EMSGSIZE);
3370		kfree_skb(skb);
3371		goto errout;
3372	}
3373	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
3374	return;
3375errout:
3376	if (err < 0)
3377		rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
3378}
3379
 
3380void neigh_app_ns(struct neighbour *n)
3381{
3382	__neigh_notify(n, RTM_GETNEIGH, NLM_F_REQUEST, 0);
3383}
3384EXPORT_SYMBOL(neigh_app_ns);
 
3385
3386#ifdef CONFIG_SYSCTL
3387static int unres_qlen_max = INT_MAX / SKB_TRUESIZE(ETH_FRAME_LEN);
3388
3389static int proc_unres_qlen(struct ctl_table *ctl, int write,
3390			   void *buffer, size_t *lenp, loff_t *ppos)
3391{
3392	int size, ret;
3393	struct ctl_table tmp = *ctl;
3394
3395	tmp.extra1 = SYSCTL_ZERO;
3396	tmp.extra2 = &unres_qlen_max;
3397	tmp.data = &size;
3398
3399	size = *(int *)ctl->data / SKB_TRUESIZE(ETH_FRAME_LEN);
3400	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
3401
3402	if (write && !ret)
3403		*(int *)ctl->data = size * SKB_TRUESIZE(ETH_FRAME_LEN);
3404	return ret;
3405}
3406
3407static struct neigh_parms *neigh_get_dev_parms_rcu(struct net_device *dev,
3408						   int family)
3409{
3410	switch (family) {
3411	case AF_INET:
3412		return __in_dev_arp_parms_get_rcu(dev);
3413	case AF_INET6:
3414		return __in6_dev_nd_parms_get_rcu(dev);
3415	}
3416	return NULL;
3417}
3418
3419static void neigh_copy_dflt_parms(struct net *net, struct neigh_parms *p,
3420				  int index)
3421{
3422	struct net_device *dev;
3423	int family = neigh_parms_family(p);
3424
3425	rcu_read_lock();
3426	for_each_netdev_rcu(net, dev) {
3427		struct neigh_parms *dst_p =
3428				neigh_get_dev_parms_rcu(dev, family);
3429
3430		if (dst_p && !test_bit(index, dst_p->data_state))
3431			dst_p->data[index] = p->data[index];
3432	}
3433	rcu_read_unlock();
3434}
3435
3436static void neigh_proc_update(struct ctl_table *ctl, int write)
3437{
3438	struct net_device *dev = ctl->extra1;
3439	struct neigh_parms *p = ctl->extra2;
3440	struct net *net = neigh_parms_net(p);
3441	int index = (int *) ctl->data - p->data;
3442
3443	if (!write)
3444		return;
3445
3446	set_bit(index, p->data_state);
3447	if (index == NEIGH_VAR_DELAY_PROBE_TIME)
3448		call_netevent_notifiers(NETEVENT_DELAY_PROBE_TIME_UPDATE, p);
3449	if (!dev) /* NULL dev means this is default value */
3450		neigh_copy_dflt_parms(net, p, index);
3451}
3452
3453static int neigh_proc_dointvec_zero_intmax(struct ctl_table *ctl, int write,
3454					   void *buffer, size_t *lenp,
3455					   loff_t *ppos)
3456{
3457	struct ctl_table tmp = *ctl;
3458	int ret;
3459
3460	tmp.extra1 = SYSCTL_ZERO;
3461	tmp.extra2 = SYSCTL_INT_MAX;
3462
3463	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
3464	neigh_proc_update(ctl, write);
3465	return ret;
3466}
3467
3468int neigh_proc_dointvec(struct ctl_table *ctl, int write, void *buffer,
3469			size_t *lenp, loff_t *ppos)
3470{
3471	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
3472
3473	neigh_proc_update(ctl, write);
3474	return ret;
3475}
3476EXPORT_SYMBOL(neigh_proc_dointvec);
3477
3478int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write, void *buffer,
3479				size_t *lenp, loff_t *ppos)
3480{
3481	int ret = proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos);
3482
3483	neigh_proc_update(ctl, write);
3484	return ret;
3485}
3486EXPORT_SYMBOL(neigh_proc_dointvec_jiffies);
3487
3488static int neigh_proc_dointvec_userhz_jiffies(struct ctl_table *ctl, int write,
3489					      void *buffer, size_t *lenp,
3490					      loff_t *ppos)
3491{
3492	int ret = proc_dointvec_userhz_jiffies(ctl, write, buffer, lenp, ppos);
3493
3494	neigh_proc_update(ctl, write);
3495	return ret;
3496}
3497
3498int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
3499				   void *buffer, size_t *lenp, loff_t *ppos)
3500{
3501	int ret = proc_dointvec_ms_jiffies(ctl, write, buffer, lenp, ppos);
3502
3503	neigh_proc_update(ctl, write);
3504	return ret;
3505}
3506EXPORT_SYMBOL(neigh_proc_dointvec_ms_jiffies);
3507
3508static int neigh_proc_dointvec_unres_qlen(struct ctl_table *ctl, int write,
3509					  void *buffer, size_t *lenp,
3510					  loff_t *ppos)
3511{
3512	int ret = proc_unres_qlen(ctl, write, buffer, lenp, ppos);
3513
3514	neigh_proc_update(ctl, write);
3515	return ret;
3516}
3517
3518static int neigh_proc_base_reachable_time(struct ctl_table *ctl, int write,
3519					  void *buffer, size_t *lenp,
3520					  loff_t *ppos)
3521{
3522	struct neigh_parms *p = ctl->extra2;
3523	int ret;
3524
3525	if (strcmp(ctl->procname, "base_reachable_time") == 0)
3526		ret = neigh_proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos);
3527	else if (strcmp(ctl->procname, "base_reachable_time_ms") == 0)
3528		ret = neigh_proc_dointvec_ms_jiffies(ctl, write, buffer, lenp, ppos);
3529	else
3530		ret = -1;
3531
3532	if (write && ret == 0) {
3533		/* update reachable_time as well, otherwise, the change will
3534		 * only be effective after the next time neigh_periodic_work
3535		 * decides to recompute it
3536		 */
3537		p->reachable_time =
3538			neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
3539	}
3540	return ret;
3541}
3542
3543#define NEIGH_PARMS_DATA_OFFSET(index)	\
3544	(&((struct neigh_parms *) 0)->data[index])
3545
3546#define NEIGH_SYSCTL_ENTRY(attr, data_attr, name, mval, proc) \
3547	[NEIGH_VAR_ ## attr] = { \
3548		.procname	= name, \
3549		.data		= NEIGH_PARMS_DATA_OFFSET(NEIGH_VAR_ ## data_attr), \
3550		.maxlen		= sizeof(int), \
3551		.mode		= mval, \
3552		.proc_handler	= proc, \
3553	}
3554
3555#define NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(attr, name) \
3556	NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_zero_intmax)
3557
3558#define NEIGH_SYSCTL_JIFFIES_ENTRY(attr, name) \
3559	NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_jiffies)
3560
3561#define NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(attr, name) \
3562	NEIGH_SYSCTL_ENTRY(attr, attr, name, 0644, neigh_proc_dointvec_userhz_jiffies)
3563
3564#define NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(attr, data_attr, name) \
3565	NEIGH_SYSCTL_ENTRY(attr, data_attr, name, 0644, neigh_proc_dointvec_ms_jiffies)
3566
3567#define NEIGH_SYSCTL_UNRES_QLEN_REUSED_ENTRY(attr, data_attr, name) \
3568	NEIGH_SYSCTL_ENTRY(attr, data_attr, name, 0644, neigh_proc_dointvec_unres_qlen)
3569
3570static struct neigh_sysctl_table {
3571	struct ctl_table_header *sysctl_header;
3572	struct ctl_table neigh_vars[NEIGH_VAR_MAX + 1];
3573} neigh_sysctl_template __read_mostly = {
3574	.neigh_vars = {
3575		NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(MCAST_PROBES, "mcast_solicit"),
3576		NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(UCAST_PROBES, "ucast_solicit"),
3577		NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(APP_PROBES, "app_solicit"),
3578		NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(MCAST_REPROBES, "mcast_resolicit"),
3579		NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(RETRANS_TIME, "retrans_time"),
3580		NEIGH_SYSCTL_JIFFIES_ENTRY(BASE_REACHABLE_TIME, "base_reachable_time"),
3581		NEIGH_SYSCTL_JIFFIES_ENTRY(DELAY_PROBE_TIME, "delay_first_probe_time"),
3582		NEIGH_SYSCTL_JIFFIES_ENTRY(GC_STALETIME, "gc_stale_time"),
3583		NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(QUEUE_LEN_BYTES, "unres_qlen_bytes"),
3584		NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(PROXY_QLEN, "proxy_qlen"),
3585		NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(ANYCAST_DELAY, "anycast_delay"),
3586		NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(PROXY_DELAY, "proxy_delay"),
3587		NEIGH_SYSCTL_USERHZ_JIFFIES_ENTRY(LOCKTIME, "locktime"),
3588		NEIGH_SYSCTL_UNRES_QLEN_REUSED_ENTRY(QUEUE_LEN, QUEUE_LEN_BYTES, "unres_qlen"),
3589		NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(RETRANS_TIME_MS, RETRANS_TIME, "retrans_time_ms"),
3590		NEIGH_SYSCTL_MS_JIFFIES_REUSED_ENTRY(BASE_REACHABLE_TIME_MS, BASE_REACHABLE_TIME, "base_reachable_time_ms"),
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3591		[NEIGH_VAR_GC_INTERVAL] = {
3592			.procname	= "gc_interval",
3593			.maxlen		= sizeof(int),
3594			.mode		= 0644,
3595			.proc_handler	= proc_dointvec_jiffies,
3596		},
3597		[NEIGH_VAR_GC_THRESH1] = {
3598			.procname	= "gc_thresh1",
3599			.maxlen		= sizeof(int),
3600			.mode		= 0644,
3601			.extra1		= SYSCTL_ZERO,
3602			.extra2		= SYSCTL_INT_MAX,
3603			.proc_handler	= proc_dointvec_minmax,
3604		},
3605		[NEIGH_VAR_GC_THRESH2] = {
3606			.procname	= "gc_thresh2",
3607			.maxlen		= sizeof(int),
3608			.mode		= 0644,
3609			.extra1		= SYSCTL_ZERO,
3610			.extra2		= SYSCTL_INT_MAX,
3611			.proc_handler	= proc_dointvec_minmax,
3612		},
3613		[NEIGH_VAR_GC_THRESH3] = {
3614			.procname	= "gc_thresh3",
3615			.maxlen		= sizeof(int),
3616			.mode		= 0644,
3617			.extra1		= SYSCTL_ZERO,
3618			.extra2		= SYSCTL_INT_MAX,
3619			.proc_handler	= proc_dointvec_minmax,
3620		},
3621		{},
3622	},
3623};
3624
3625int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
3626			  proc_handler *handler)
3627{
3628	int i;
3629	struct neigh_sysctl_table *t;
3630	const char *dev_name_source;
3631	char neigh_path[ sizeof("net//neigh/") + IFNAMSIZ + IFNAMSIZ ];
3632	char *p_name;
3633
3634	t = kmemdup(&neigh_sysctl_template, sizeof(*t), GFP_KERNEL);
3635	if (!t)
3636		goto err;
3637
3638	for (i = 0; i < NEIGH_VAR_GC_INTERVAL; i++) {
3639		t->neigh_vars[i].data += (long) p;
3640		t->neigh_vars[i].extra1 = dev;
3641		t->neigh_vars[i].extra2 = p;
3642	}
 
 
 
 
 
 
 
 
 
 
3643
3644	if (dev) {
3645		dev_name_source = dev->name;
3646		/* Terminate the table early */
3647		memset(&t->neigh_vars[NEIGH_VAR_GC_INTERVAL], 0,
3648		       sizeof(t->neigh_vars[NEIGH_VAR_GC_INTERVAL]));
3649	} else {
3650		struct neigh_table *tbl = p->tbl;
3651		dev_name_source = "default";
3652		t->neigh_vars[NEIGH_VAR_GC_INTERVAL].data = &tbl->gc_interval;
3653		t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = &tbl->gc_thresh1;
3654		t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = &tbl->gc_thresh2;
3655		t->neigh_vars[NEIGH_VAR_GC_THRESH3].data = &tbl->gc_thresh3;
3656	}
3657
 
3658	if (handler) {
3659		/* RetransTime */
3660		t->neigh_vars[NEIGH_VAR_RETRANS_TIME].proc_handler = handler;
 
3661		/* ReachableTime */
3662		t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].proc_handler = handler;
 
3663		/* RetransTime (in milliseconds)*/
3664		t->neigh_vars[NEIGH_VAR_RETRANS_TIME_MS].proc_handler = handler;
 
3665		/* ReachableTime (in milliseconds) */
3666		t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].proc_handler = handler;
3667	} else {
3668		/* Those handlers will update p->reachable_time after
3669		 * base_reachable_time(_ms) is set to ensure the new timer starts being
3670		 * applied after the next neighbour update instead of waiting for
3671		 * neigh_periodic_work to update its value (can be multiple minutes)
3672		 * So any handler that replaces them should do this as well
3673		 */
3674		/* ReachableTime */
3675		t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].proc_handler =
3676			neigh_proc_base_reachable_time;
3677		/* ReachableTime (in milliseconds) */
3678		t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].proc_handler =
3679			neigh_proc_base_reachable_time;
3680	}
3681
3682	/* Don't export sysctls to unprivileged users */
3683	if (neigh_parms_net(p)->user_ns != &init_user_ns)
3684		t->neigh_vars[0].procname = NULL;
3685
3686	switch (neigh_parms_family(p)) {
3687	case AF_INET:
3688	      p_name = "ipv4";
3689	      break;
3690	case AF_INET6:
3691	      p_name = "ipv6";
3692	      break;
3693	default:
3694	      BUG();
3695	}
3696
3697	snprintf(neigh_path, sizeof(neigh_path), "net/%s/neigh/%s",
3698		p_name, dev_name_source);
3699	t->sysctl_header =
3700		register_net_sysctl(neigh_parms_net(p), neigh_path, t->neigh_vars);
3701	if (!t->sysctl_header)
3702		goto free;
3703
3704	p->sysctl_table = t;
3705	return 0;
3706
3707free:
3708	kfree(t);
3709err:
3710	return -ENOBUFS;
3711}
3712EXPORT_SYMBOL(neigh_sysctl_register);
3713
3714void neigh_sysctl_unregister(struct neigh_parms *p)
3715{
3716	if (p->sysctl_table) {
3717		struct neigh_sysctl_table *t = p->sysctl_table;
3718		p->sysctl_table = NULL;
3719		unregister_net_sysctl_table(t->sysctl_header);
3720		kfree(t);
3721	}
3722}
3723EXPORT_SYMBOL(neigh_sysctl_unregister);
3724
3725#endif	/* CONFIG_SYSCTL */
3726
3727static int __init neigh_init(void)
3728{
3729	rtnl_register(PF_UNSPEC, RTM_NEWNEIGH, neigh_add, NULL, 0);
3730	rtnl_register(PF_UNSPEC, RTM_DELNEIGH, neigh_delete, NULL, 0);
3731	rtnl_register(PF_UNSPEC, RTM_GETNEIGH, neigh_get, neigh_dump_info, 0);
3732
3733	rtnl_register(PF_UNSPEC, RTM_GETNEIGHTBL, NULL, neightbl_dump_info,
3734		      0);
3735	rtnl_register(PF_UNSPEC, RTM_SETNEIGHTBL, neightbl_set, NULL, 0);
3736
3737	return 0;
3738}
3739
3740subsys_initcall(neigh_init);
v3.5.6
 
   1/*
   2 *	Generic address resolution entity
   3 *
   4 *	Authors:
   5 *	Pedro Roque		<roque@di.fc.ul.pt>
   6 *	Alexey Kuznetsov	<kuznet@ms2.inr.ac.ru>
   7 *
   8 *	This program is free software; you can redistribute it and/or
   9 *      modify it under the terms of the GNU General Public License
  10 *      as published by the Free Software Foundation; either version
  11 *      2 of the License, or (at your option) any later version.
  12 *
  13 *	Fixes:
  14 *	Vitaly E. Lavrov	releasing NULL neighbor in neigh_add.
  15 *	Harald Welte		Add neighbour cache statistics like rtstat
  16 */
  17
  18#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  19
  20#include <linux/slab.h>
 
  21#include <linux/types.h>
  22#include <linux/kernel.h>
  23#include <linux/module.h>
  24#include <linux/socket.h>
  25#include <linux/netdevice.h>
  26#include <linux/proc_fs.h>
  27#ifdef CONFIG_SYSCTL
  28#include <linux/sysctl.h>
  29#endif
  30#include <linux/times.h>
  31#include <net/net_namespace.h>
  32#include <net/neighbour.h>
 
  33#include <net/dst.h>
  34#include <net/sock.h>
  35#include <net/netevent.h>
  36#include <net/netlink.h>
  37#include <linux/rtnetlink.h>
  38#include <linux/random.h>
  39#include <linux/string.h>
  40#include <linux/log2.h>
 
 
 
 
  41
  42#define NEIGH_DEBUG 1
  43
  44#define NEIGH_PRINTK(x...) printk(x)
  45#define NEIGH_NOPRINTK(x...) do { ; } while(0)
  46#define NEIGH_PRINTK1 NEIGH_NOPRINTK
  47#define NEIGH_PRINTK2 NEIGH_NOPRINTK
  48
  49#if NEIGH_DEBUG >= 1
  50#undef NEIGH_PRINTK1
  51#define NEIGH_PRINTK1 NEIGH_PRINTK
  52#endif
  53#if NEIGH_DEBUG >= 2
  54#undef NEIGH_PRINTK2
  55#define NEIGH_PRINTK2 NEIGH_PRINTK
  56#endif
  57
  58#define PNEIGH_HASHMASK		0xF
  59
  60static void neigh_timer_handler(unsigned long arg);
  61static void __neigh_notify(struct neighbour *n, int type, int flags);
  62static void neigh_update_notify(struct neighbour *neigh);
  63static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 
 
  64
  65static struct neigh_table *neigh_tables;
  66#ifdef CONFIG_PROC_FS
  67static const struct file_operations neigh_stat_seq_fops;
  68#endif
  69
  70/*
  71   Neighbour hash table buckets are protected with rwlock tbl->lock.
  72
  73   - All the scans/updates to hash buckets MUST be made under this lock.
  74   - NOTHING clever should be made under this lock: no callbacks
  75     to protocol backends, no attempts to send something to network.
  76     It will result in deadlocks, if backend/driver wants to use neighbour
  77     cache.
  78   - If the entry requires some non-trivial actions, increase
  79     its reference count and release table lock.
  80
  81   Neighbour entries are protected:
  82   - with reference count.
  83   - with rwlock neigh->lock
  84
  85   Reference count prevents destruction.
  86
  87   neigh->lock mainly serializes ll address data and its validity state.
  88   However, the same lock is used to protect another entry fields:
  89    - timer
  90    - resolution queue
  91
  92   Again, nothing clever shall be made under neigh->lock,
  93   the most complicated procedure, which we allow is dev->hard_header.
  94   It is supposed, that dev->hard_header is simplistic and does
  95   not make callbacks to neighbour tables.
  96
  97   The last lock is neigh_tbl_lock. It is pure SMP lock, protecting
  98   list of neighbour tables. This list is used only in process context,
  99 */
 100
 101static DEFINE_RWLOCK(neigh_tbl_lock);
 102
 103static int neigh_blackhole(struct neighbour *neigh, struct sk_buff *skb)
 104{
 105	kfree_skb(skb);
 106	return -ENETDOWN;
 107}
 108
 109static void neigh_cleanup_and_release(struct neighbour *neigh)
 110{
 111	if (neigh->parms->neigh_cleanup)
 112		neigh->parms->neigh_cleanup(neigh);
 113
 114	__neigh_notify(neigh, RTM_DELNEIGH, 0);
 115	neigh_release(neigh);
 116}
 117
 118/*
 119 * It is random distribution in the interval (1/2)*base...(3/2)*base.
 120 * It corresponds to default IPv6 settings and is not overridable,
 121 * because it is really reasonable choice.
 122 */
 123
 124unsigned long neigh_rand_reach_time(unsigned long base)
 125{
 126	return base ? (net_random() % base) + (base >> 1) : 0;
 127}
 128EXPORT_SYMBOL(neigh_rand_reach_time);
 129
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 130
 131static int neigh_forced_gc(struct neigh_table *tbl)
 132{
 
 
 
 133	int shrunk = 0;
 134	int i;
 135	struct neigh_hash_table *nht;
 136
 137	NEIGH_CACHE_STAT_INC(tbl, forced_gc_runs);
 138
 139	write_lock_bh(&tbl->lock);
 140	nht = rcu_dereference_protected(tbl->nht,
 141					lockdep_is_held(&tbl->lock));
 142	for (i = 0; i < (1 << nht->hash_shift); i++) {
 143		struct neighbour *n;
 144		struct neighbour __rcu **np;
 145
 146		np = &nht->hash_buckets[i];
 147		while ((n = rcu_dereference_protected(*np,
 148					lockdep_is_held(&tbl->lock))) != NULL) {
 149			/* Neighbour record may be discarded if:
 150			 * - nobody refers to it.
 151			 * - it is not permanent
 152			 */
 153			write_lock(&n->lock);
 154			if (atomic_read(&n->refcnt) == 1 &&
 155			    !(n->nud_state & NUD_PERMANENT)) {
 156				rcu_assign_pointer(*np,
 157					rcu_dereference_protected(n->next,
 158						  lockdep_is_held(&tbl->lock)));
 159				n->dead = 1;
 160				shrunk	= 1;
 161				write_unlock(&n->lock);
 162				neigh_cleanup_and_release(n);
 163				continue;
 164			}
 165			write_unlock(&n->lock);
 166			np = &n->next;
 
 
 
 
 167		}
 168	}
 169
 170	tbl->last_flush = jiffies;
 171
 172	write_unlock_bh(&tbl->lock);
 173
 174	return shrunk;
 175}
 176
 177static void neigh_add_timer(struct neighbour *n, unsigned long when)
 178{
 179	neigh_hold(n);
 180	if (unlikely(mod_timer(&n->timer, when))) {
 181		printk("NEIGH: BUG, double timer add, state is %x\n",
 182		       n->nud_state);
 183		dump_stack();
 184	}
 185}
 186
 187static int neigh_del_timer(struct neighbour *n)
 188{
 189	if ((n->nud_state & NUD_IN_TIMER) &&
 190	    del_timer(&n->timer)) {
 191		neigh_release(n);
 192		return 1;
 193	}
 194	return 0;
 195}
 196
 197static void pneigh_queue_purge(struct sk_buff_head *list)
 198{
 199	struct sk_buff *skb;
 200
 201	while ((skb = skb_dequeue(list)) != NULL) {
 202		dev_put(skb->dev);
 203		kfree_skb(skb);
 204	}
 205}
 206
 207static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev)
 
 208{
 209	int i;
 210	struct neigh_hash_table *nht;
 211
 212	nht = rcu_dereference_protected(tbl->nht,
 213					lockdep_is_held(&tbl->lock));
 214
 215	for (i = 0; i < (1 << nht->hash_shift); i++) {
 216		struct neighbour *n;
 217		struct neighbour __rcu **np = &nht->hash_buckets[i];
 218
 219		while ((n = rcu_dereference_protected(*np,
 220					lockdep_is_held(&tbl->lock))) != NULL) {
 221			if (dev && n->dev != dev) {
 222				np = &n->next;
 223				continue;
 224			}
 
 
 
 
 225			rcu_assign_pointer(*np,
 226				   rcu_dereference_protected(n->next,
 227						lockdep_is_held(&tbl->lock)));
 228			write_lock(&n->lock);
 229			neigh_del_timer(n);
 230			n->dead = 1;
 231
 232			if (atomic_read(&n->refcnt) != 1) {
 233				/* The most unpleasant situation.
 234				   We must destroy neighbour entry,
 235				   but someone still uses it.
 236
 237				   The destroy will be delayed until
 238				   the last user releases us, but
 239				   we must kill timers etc. and move
 240				   it to safe state.
 241				 */
 242				skb_queue_purge(&n->arp_queue);
 243				n->arp_queue_len_bytes = 0;
 244				n->output = neigh_blackhole;
 245				if (n->nud_state & NUD_VALID)
 246					n->nud_state = NUD_NOARP;
 247				else
 248					n->nud_state = NUD_NONE;
 249				NEIGH_PRINTK2("neigh %p is stray.\n", n);
 250			}
 251			write_unlock(&n->lock);
 252			neigh_cleanup_and_release(n);
 253		}
 254	}
 255}
 256
 257void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev)
 258{
 259	write_lock_bh(&tbl->lock);
 260	neigh_flush_dev(tbl, dev);
 261	write_unlock_bh(&tbl->lock);
 262}
 263EXPORT_SYMBOL(neigh_changeaddr);
 264
 265int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 
 266{
 267	write_lock_bh(&tbl->lock);
 268	neigh_flush_dev(tbl, dev);
 269	pneigh_ifdown(tbl, dev);
 270	write_unlock_bh(&tbl->lock);
 271
 272	del_timer_sync(&tbl->proxy_timer);
 273	pneigh_queue_purge(&tbl->proxy_queue);
 274	return 0;
 275}
 
 
 
 
 
 
 
 
 
 
 
 
 
 276EXPORT_SYMBOL(neigh_ifdown);
 277
 278static struct neighbour *neigh_alloc(struct neigh_table *tbl, struct net_device *dev)
 
 
 279{
 280	struct neighbour *n = NULL;
 281	unsigned long now = jiffies;
 282	int entries;
 283
 284	entries = atomic_inc_return(&tbl->entries) - 1;
 
 
 
 285	if (entries >= tbl->gc_thresh3 ||
 286	    (entries >= tbl->gc_thresh2 &&
 287	     time_after(now, tbl->last_flush + 5 * HZ))) {
 288		if (!neigh_forced_gc(tbl) &&
 289		    entries >= tbl->gc_thresh3)
 
 
 
 290			goto out_entries;
 
 291	}
 292
 293	if (tbl->entry_size)
 294		n = kzalloc(tbl->entry_size, GFP_ATOMIC);
 295	else {
 296		int sz = sizeof(*n) + tbl->key_len;
 297
 298		sz = ALIGN(sz, NEIGH_PRIV_ALIGN);
 299		sz += dev->neigh_priv_len;
 300		n = kzalloc(sz, GFP_ATOMIC);
 301	}
 302	if (!n)
 303		goto out_entries;
 304
 305	skb_queue_head_init(&n->arp_queue);
 306	rwlock_init(&n->lock);
 307	seqlock_init(&n->ha_lock);
 308	n->updated	  = n->used = now;
 309	n->nud_state	  = NUD_NONE;
 310	n->output	  = neigh_blackhole;
 311	seqlock_init(&n->hh.hh_lock);
 312	n->parms	  = neigh_parms_clone(&tbl->parms);
 313	setup_timer(&n->timer, neigh_timer_handler, (unsigned long)n);
 314
 315	NEIGH_CACHE_STAT_INC(tbl, allocs);
 316	n->tbl		  = tbl;
 317	atomic_set(&n->refcnt, 1);
 318	n->dead		  = 1;
 
 
 
 319out:
 320	return n;
 321
 322out_entries:
 323	atomic_dec(&tbl->entries);
 
 324	goto out;
 325}
 326
 327static void neigh_get_hash_rnd(u32 *x)
 328{
 329	get_random_bytes(x, sizeof(*x));
 330	*x |= 1;
 331}
 332
 333static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift)
 334{
 335	size_t size = (1 << shift) * sizeof(struct neighbour *);
 336	struct neigh_hash_table *ret;
 337	struct neighbour __rcu **buckets;
 338	int i;
 339
 340	ret = kmalloc(sizeof(*ret), GFP_ATOMIC);
 341	if (!ret)
 342		return NULL;
 343	if (size <= PAGE_SIZE)
 344		buckets = kzalloc(size, GFP_ATOMIC);
 345	else
 346		buckets = (struct neighbour __rcu **)
 347			  __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
 348					   get_order(size));
 
 
 349	if (!buckets) {
 350		kfree(ret);
 351		return NULL;
 352	}
 353	ret->hash_buckets = buckets;
 354	ret->hash_shift = shift;
 355	for (i = 0; i < NEIGH_NUM_HASH_RND; i++)
 356		neigh_get_hash_rnd(&ret->hash_rnd[i]);
 357	return ret;
 358}
 359
 360static void neigh_hash_free_rcu(struct rcu_head *head)
 361{
 362	struct neigh_hash_table *nht = container_of(head,
 363						    struct neigh_hash_table,
 364						    rcu);
 365	size_t size = (1 << nht->hash_shift) * sizeof(struct neighbour *);
 366	struct neighbour __rcu **buckets = nht->hash_buckets;
 367
 368	if (size <= PAGE_SIZE)
 369		kfree(buckets);
 370	else
 
 371		free_pages((unsigned long)buckets, get_order(size));
 
 372	kfree(nht);
 373}
 374
 375static struct neigh_hash_table *neigh_hash_grow(struct neigh_table *tbl,
 376						unsigned long new_shift)
 377{
 378	unsigned int i, hash;
 379	struct neigh_hash_table *new_nht, *old_nht;
 380
 381	NEIGH_CACHE_STAT_INC(tbl, hash_grows);
 382
 383	old_nht = rcu_dereference_protected(tbl->nht,
 384					    lockdep_is_held(&tbl->lock));
 385	new_nht = neigh_hash_alloc(new_shift);
 386	if (!new_nht)
 387		return old_nht;
 388
 389	for (i = 0; i < (1 << old_nht->hash_shift); i++) {
 390		struct neighbour *n, *next;
 391
 392		for (n = rcu_dereference_protected(old_nht->hash_buckets[i],
 393						   lockdep_is_held(&tbl->lock));
 394		     n != NULL;
 395		     n = next) {
 396			hash = tbl->hash(n->primary_key, n->dev,
 397					 new_nht->hash_rnd);
 398
 399			hash >>= (32 - new_nht->hash_shift);
 400			next = rcu_dereference_protected(n->next,
 401						lockdep_is_held(&tbl->lock));
 402
 403			rcu_assign_pointer(n->next,
 404					   rcu_dereference_protected(
 405						new_nht->hash_buckets[hash],
 406						lockdep_is_held(&tbl->lock)));
 407			rcu_assign_pointer(new_nht->hash_buckets[hash], n);
 408		}
 409	}
 410
 411	rcu_assign_pointer(tbl->nht, new_nht);
 412	call_rcu(&old_nht->rcu, neigh_hash_free_rcu);
 413	return new_nht;
 414}
 415
 416struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
 417			       struct net_device *dev)
 418{
 419	struct neighbour *n;
 420	int key_len = tbl->key_len;
 421	u32 hash_val;
 422	struct neigh_hash_table *nht;
 423
 424	NEIGH_CACHE_STAT_INC(tbl, lookups);
 425
 426	rcu_read_lock_bh();
 427	nht = rcu_dereference_bh(tbl->nht);
 428	hash_val = tbl->hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
 429
 430	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
 431	     n != NULL;
 432	     n = rcu_dereference_bh(n->next)) {
 433		if (dev == n->dev && !memcmp(n->primary_key, pkey, key_len)) {
 434			if (!atomic_inc_not_zero(&n->refcnt))
 435				n = NULL;
 436			NEIGH_CACHE_STAT_INC(tbl, hits);
 437			break;
 438		}
 439	}
 440
 441	rcu_read_unlock_bh();
 442	return n;
 443}
 444EXPORT_SYMBOL(neigh_lookup);
 445
 446struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,
 447				     const void *pkey)
 448{
 449	struct neighbour *n;
 450	int key_len = tbl->key_len;
 451	u32 hash_val;
 452	struct neigh_hash_table *nht;
 453
 454	NEIGH_CACHE_STAT_INC(tbl, lookups);
 455
 456	rcu_read_lock_bh();
 457	nht = rcu_dereference_bh(tbl->nht);
 458	hash_val = tbl->hash(pkey, NULL, nht->hash_rnd) >> (32 - nht->hash_shift);
 459
 460	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
 461	     n != NULL;
 462	     n = rcu_dereference_bh(n->next)) {
 463		if (!memcmp(n->primary_key, pkey, key_len) &&
 464		    net_eq(dev_net(n->dev), net)) {
 465			if (!atomic_inc_not_zero(&n->refcnt))
 466				n = NULL;
 467			NEIGH_CACHE_STAT_INC(tbl, hits);
 468			break;
 469		}
 470	}
 471
 472	rcu_read_unlock_bh();
 473	return n;
 474}
 475EXPORT_SYMBOL(neigh_lookup_nodev);
 476
 477struct neighbour *neigh_create(struct neigh_table *tbl, const void *pkey,
 478			       struct net_device *dev)
 
 
 479{
 
 480	u32 hash_val;
 481	int key_len = tbl->key_len;
 482	int error;
 483	struct neighbour *n1, *rc, *n = neigh_alloc(tbl, dev);
 484	struct neigh_hash_table *nht;
 485
 
 
 486	if (!n) {
 487		rc = ERR_PTR(-ENOBUFS);
 488		goto out;
 489	}
 490
 491	memcpy(n->primary_key, pkey, key_len);
 492	n->dev = dev;
 493	dev_hold(dev);
 494
 495	/* Protocol specific setup. */
 496	if (tbl->constructor &&	(error = tbl->constructor(n)) < 0) {
 497		rc = ERR_PTR(error);
 498		goto out_neigh_release;
 499	}
 500
 501	if (dev->netdev_ops->ndo_neigh_construct) {
 502		error = dev->netdev_ops->ndo_neigh_construct(n);
 503		if (error < 0) {
 504			rc = ERR_PTR(error);
 505			goto out_neigh_release;
 506		}
 507	}
 508
 509	/* Device specific setup. */
 510	if (n->parms->neigh_setup &&
 511	    (error = n->parms->neigh_setup(n)) < 0) {
 512		rc = ERR_PTR(error);
 513		goto out_neigh_release;
 514	}
 515
 516	n->confirmed = jiffies - (n->parms->base_reachable_time << 1);
 517
 518	write_lock_bh(&tbl->lock);
 519	nht = rcu_dereference_protected(tbl->nht,
 520					lockdep_is_held(&tbl->lock));
 521
 522	if (atomic_read(&tbl->entries) > (1 << nht->hash_shift))
 523		nht = neigh_hash_grow(tbl, nht->hash_shift + 1);
 524
 525	hash_val = tbl->hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
 526
 527	if (n->parms->dead) {
 528		rc = ERR_PTR(-EINVAL);
 529		goto out_tbl_unlock;
 530	}
 531
 532	for (n1 = rcu_dereference_protected(nht->hash_buckets[hash_val],
 533					    lockdep_is_held(&tbl->lock));
 534	     n1 != NULL;
 535	     n1 = rcu_dereference_protected(n1->next,
 536			lockdep_is_held(&tbl->lock))) {
 537		if (dev == n1->dev && !memcmp(n1->primary_key, pkey, key_len)) {
 538			neigh_hold(n1);
 
 539			rc = n1;
 540			goto out_tbl_unlock;
 541		}
 542	}
 543
 544	n->dead = 0;
 545	neigh_hold(n);
 
 
 
 
 546	rcu_assign_pointer(n->next,
 547			   rcu_dereference_protected(nht->hash_buckets[hash_val],
 548						     lockdep_is_held(&tbl->lock)));
 549	rcu_assign_pointer(nht->hash_buckets[hash_val], n);
 550	write_unlock_bh(&tbl->lock);
 551	NEIGH_PRINTK2("neigh %p is created.\n", n);
 552	rc = n;
 553out:
 554	return rc;
 555out_tbl_unlock:
 556	write_unlock_bh(&tbl->lock);
 557out_neigh_release:
 
 
 558	neigh_release(n);
 559	goto out;
 560}
 561EXPORT_SYMBOL(neigh_create);
 562
 563static u32 pneigh_hash(const void *pkey, int key_len)
 
 
 
 
 
 
 
 564{
 565	u32 hash_val = *(u32 *)(pkey + key_len - 4);
 566	hash_val ^= (hash_val >> 16);
 567	hash_val ^= hash_val >> 8;
 568	hash_val ^= hash_val >> 4;
 569	hash_val &= PNEIGH_HASHMASK;
 570	return hash_val;
 571}
 572
 573static struct pneigh_entry *__pneigh_lookup_1(struct pneigh_entry *n,
 574					      struct net *net,
 575					      const void *pkey,
 576					      int key_len,
 577					      struct net_device *dev)
 578{
 579	while (n) {
 580		if (!memcmp(n->key, pkey, key_len) &&
 581		    net_eq(pneigh_net(n), net) &&
 582		    (n->dev == dev || !n->dev))
 583			return n;
 584		n = n->next;
 585	}
 586	return NULL;
 587}
 588
 589struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl,
 590		struct net *net, const void *pkey, struct net_device *dev)
 591{
 592	int key_len = tbl->key_len;
 593	u32 hash_val = pneigh_hash(pkey, key_len);
 594
 595	return __pneigh_lookup_1(tbl->phash_buckets[hash_val],
 596				 net, pkey, key_len, dev);
 597}
 598EXPORT_SYMBOL_GPL(__pneigh_lookup);
 599
 600struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl,
 601				    struct net *net, const void *pkey,
 602				    struct net_device *dev, int creat)
 603{
 604	struct pneigh_entry *n;
 605	int key_len = tbl->key_len;
 606	u32 hash_val = pneigh_hash(pkey, key_len);
 607
 608	read_lock_bh(&tbl->lock);
 609	n = __pneigh_lookup_1(tbl->phash_buckets[hash_val],
 610			      net, pkey, key_len, dev);
 611	read_unlock_bh(&tbl->lock);
 612
 613	if (n || !creat)
 614		goto out;
 615
 616	ASSERT_RTNL();
 617
 618	n = kmalloc(sizeof(*n) + key_len, GFP_KERNEL);
 619	if (!n)
 620		goto out;
 621
 622	write_pnet(&n->net, hold_net(net));
 
 623	memcpy(n->key, pkey, key_len);
 624	n->dev = dev;
 625	if (dev)
 626		dev_hold(dev);
 627
 628	if (tbl->pconstructor && tbl->pconstructor(n)) {
 629		if (dev)
 630			dev_put(dev);
 631		release_net(net);
 632		kfree(n);
 633		n = NULL;
 634		goto out;
 635	}
 636
 637	write_lock_bh(&tbl->lock);
 638	n->next = tbl->phash_buckets[hash_val];
 639	tbl->phash_buckets[hash_val] = n;
 640	write_unlock_bh(&tbl->lock);
 641out:
 642	return n;
 643}
 644EXPORT_SYMBOL(pneigh_lookup);
 645
 646
 647int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *pkey,
 648		  struct net_device *dev)
 649{
 650	struct pneigh_entry *n, **np;
 651	int key_len = tbl->key_len;
 652	u32 hash_val = pneigh_hash(pkey, key_len);
 653
 654	write_lock_bh(&tbl->lock);
 655	for (np = &tbl->phash_buckets[hash_val]; (n = *np) != NULL;
 656	     np = &n->next) {
 657		if (!memcmp(n->key, pkey, key_len) && n->dev == dev &&
 658		    net_eq(pneigh_net(n), net)) {
 659			*np = n->next;
 660			write_unlock_bh(&tbl->lock);
 661			if (tbl->pdestructor)
 662				tbl->pdestructor(n);
 663			if (n->dev)
 664				dev_put(n->dev);
 665			release_net(pneigh_net(n));
 666			kfree(n);
 667			return 0;
 668		}
 669	}
 670	write_unlock_bh(&tbl->lock);
 671	return -ENOENT;
 672}
 673
 674static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 
 675{
 676	struct pneigh_entry *n, **np;
 677	u32 h;
 678
 679	for (h = 0; h <= PNEIGH_HASHMASK; h++) {
 680		np = &tbl->phash_buckets[h];
 681		while ((n = *np) != NULL) {
 682			if (!dev || n->dev == dev) {
 683				*np = n->next;
 684				if (tbl->pdestructor)
 685					tbl->pdestructor(n);
 686				if (n->dev)
 687					dev_put(n->dev);
 688				release_net(pneigh_net(n));
 689				kfree(n);
 690				continue;
 691			}
 692			np = &n->next;
 693		}
 694	}
 
 
 
 
 
 
 
 
 
 
 695	return -ENOENT;
 696}
 697
 698static void neigh_parms_destroy(struct neigh_parms *parms);
 699
 700static inline void neigh_parms_put(struct neigh_parms *parms)
 701{
 702	if (atomic_dec_and_test(&parms->refcnt))
 703		neigh_parms_destroy(parms);
 704}
 705
 706/*
 707 *	neighbour must already be out of the table;
 708 *
 709 */
 710void neigh_destroy(struct neighbour *neigh)
 711{
 712	struct net_device *dev = neigh->dev;
 713
 714	NEIGH_CACHE_STAT_INC(neigh->tbl, destroys);
 715
 716	if (!neigh->dead) {
 717		pr_warn("Destroying alive neighbour %p\n", neigh);
 718		dump_stack();
 719		return;
 720	}
 721
 722	if (neigh_del_timer(neigh))
 723		pr_warn("Impossible event\n");
 724
 725	skb_queue_purge(&neigh->arp_queue);
 
 
 726	neigh->arp_queue_len_bytes = 0;
 727
 728	if (dev->netdev_ops->ndo_neigh_destroy)
 729		dev->netdev_ops->ndo_neigh_destroy(neigh);
 730
 731	dev_put(dev);
 732	neigh_parms_put(neigh->parms);
 733
 734	NEIGH_PRINTK2("neigh %p is destroyed.\n", neigh);
 735
 736	atomic_dec(&neigh->tbl->entries);
 737	kfree_rcu(neigh, rcu);
 738}
 739EXPORT_SYMBOL(neigh_destroy);
 740
 741/* Neighbour state is suspicious;
 742   disable fast path.
 743
 744   Called with write_locked neigh.
 745 */
 746static void neigh_suspect(struct neighbour *neigh)
 747{
 748	NEIGH_PRINTK2("neigh %p is suspected.\n", neigh);
 749
 750	neigh->output = neigh->ops->output;
 751}
 752
 753/* Neighbour state is OK;
 754   enable fast path.
 755
 756   Called with write_locked neigh.
 757 */
 758static void neigh_connect(struct neighbour *neigh)
 759{
 760	NEIGH_PRINTK2("neigh %p is connected.\n", neigh);
 761
 762	neigh->output = neigh->ops->connected_output;
 763}
 764
 765static void neigh_periodic_work(struct work_struct *work)
 766{
 767	struct neigh_table *tbl = container_of(work, struct neigh_table, gc_work.work);
 768	struct neighbour *n;
 769	struct neighbour __rcu **np;
 770	unsigned int i;
 771	struct neigh_hash_table *nht;
 772
 773	NEIGH_CACHE_STAT_INC(tbl, periodic_gc_runs);
 774
 775	write_lock_bh(&tbl->lock);
 776	nht = rcu_dereference_protected(tbl->nht,
 777					lockdep_is_held(&tbl->lock));
 778
 779	/*
 780	 *	periodically recompute ReachableTime from random function
 781	 */
 782
 783	if (time_after(jiffies, tbl->last_rand + 300 * HZ)) {
 784		struct neigh_parms *p;
 785		tbl->last_rand = jiffies;
 786		for (p = &tbl->parms; p; p = p->next)
 787			p->reachable_time =
 788				neigh_rand_reach_time(p->base_reachable_time);
 789	}
 790
 
 
 
 791	for (i = 0 ; i < (1 << nht->hash_shift); i++) {
 792		np = &nht->hash_buckets[i];
 793
 794		while ((n = rcu_dereference_protected(*np,
 795				lockdep_is_held(&tbl->lock))) != NULL) {
 796			unsigned int state;
 797
 798			write_lock(&n->lock);
 799
 800			state = n->nud_state;
 801			if (state & (NUD_PERMANENT | NUD_IN_TIMER)) {
 
 802				write_unlock(&n->lock);
 803				goto next_elt;
 804			}
 805
 806			if (time_before(n->used, n->confirmed))
 807				n->used = n->confirmed;
 808
 809			if (atomic_read(&n->refcnt) == 1 &&
 810			    (state == NUD_FAILED ||
 811			     time_after(jiffies, n->used + n->parms->gc_staletime))) {
 812				*np = n->next;
 813				n->dead = 1;
 814				write_unlock(&n->lock);
 815				neigh_cleanup_and_release(n);
 816				continue;
 817			}
 818			write_unlock(&n->lock);
 819
 820next_elt:
 821			np = &n->next;
 822		}
 823		/*
 824		 * It's fine to release lock here, even if hash table
 825		 * grows while we are preempted.
 826		 */
 827		write_unlock_bh(&tbl->lock);
 828		cond_resched();
 829		write_lock_bh(&tbl->lock);
 830		nht = rcu_dereference_protected(tbl->nht,
 831						lockdep_is_held(&tbl->lock));
 832	}
 833	/* Cycle through all hash buckets every base_reachable_time/2 ticks.
 834	 * ARP entry timeouts range from 1/2 base_reachable_time to 3/2
 835	 * base_reachable_time.
 
 836	 */
 837	schedule_delayed_work(&tbl->gc_work,
 838			      tbl->parms.base_reachable_time >> 1);
 839	write_unlock_bh(&tbl->lock);
 840}
 841
 842static __inline__ int neigh_max_probes(struct neighbour *n)
 843{
 844	struct neigh_parms *p = n->parms;
 845	return (n->nud_state & NUD_PROBE) ?
 846		p->ucast_probes :
 847		p->ucast_probes + p->app_probes + p->mcast_probes;
 848}
 849
 850static void neigh_invalidate(struct neighbour *neigh)
 851	__releases(neigh->lock)
 852	__acquires(neigh->lock)
 853{
 854	struct sk_buff *skb;
 855
 856	NEIGH_CACHE_STAT_INC(neigh->tbl, res_failed);
 857	NEIGH_PRINTK2("neigh %p is failed.\n", neigh);
 858	neigh->updated = jiffies;
 859
 860	/* It is very thin place. report_unreachable is very complicated
 861	   routine. Particularly, it can hit the same neighbour entry!
 862
 863	   So that, we try to be accurate and avoid dead loop. --ANK
 864	 */
 865	while (neigh->nud_state == NUD_FAILED &&
 866	       (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
 867		write_unlock(&neigh->lock);
 868		neigh->ops->error_report(neigh, skb);
 869		write_lock(&neigh->lock);
 870	}
 871	skb_queue_purge(&neigh->arp_queue);
 872	neigh->arp_queue_len_bytes = 0;
 873}
 874
 875static void neigh_probe(struct neighbour *neigh)
 876	__releases(neigh->lock)
 877{
 878	struct sk_buff *skb = skb_peek(&neigh->arp_queue);
 879	/* keep skb alive even if arp_queue overflows */
 880	if (skb)
 881		skb = skb_copy(skb, GFP_ATOMIC);
 882	write_unlock(&neigh->lock);
 883	neigh->ops->solicit(neigh, skb);
 
 884	atomic_inc(&neigh->probes);
 885	kfree_skb(skb);
 886}
 887
 888/* Called when a timer expires for a neighbour entry. */
 889
 890static void neigh_timer_handler(unsigned long arg)
 891{
 892	unsigned long now, next;
 893	struct neighbour *neigh = (struct neighbour *)arg;
 894	unsigned int state;
 895	int notify = 0;
 896
 897	write_lock(&neigh->lock);
 898
 899	state = neigh->nud_state;
 900	now = jiffies;
 901	next = now + HZ;
 902
 903	if (!(state & NUD_IN_TIMER))
 904		goto out;
 905
 906	if (state & NUD_REACHABLE) {
 907		if (time_before_eq(now,
 908				   neigh->confirmed + neigh->parms->reachable_time)) {
 909			NEIGH_PRINTK2("neigh %p is still alive.\n", neigh);
 910			next = neigh->confirmed + neigh->parms->reachable_time;
 911		} else if (time_before_eq(now,
 912					  neigh->used + neigh->parms->delay_probe_time)) {
 913			NEIGH_PRINTK2("neigh %p is delayed.\n", neigh);
 
 914			neigh->nud_state = NUD_DELAY;
 915			neigh->updated = jiffies;
 916			neigh_suspect(neigh);
 917			next = now + neigh->parms->delay_probe_time;
 918		} else {
 919			NEIGH_PRINTK2("neigh %p is suspected.\n", neigh);
 920			neigh->nud_state = NUD_STALE;
 921			neigh->updated = jiffies;
 922			neigh_suspect(neigh);
 923			notify = 1;
 924		}
 925	} else if (state & NUD_DELAY) {
 926		if (time_before_eq(now,
 927				   neigh->confirmed + neigh->parms->delay_probe_time)) {
 928			NEIGH_PRINTK2("neigh %p is now reachable.\n", neigh);
 
 929			neigh->nud_state = NUD_REACHABLE;
 930			neigh->updated = jiffies;
 931			neigh_connect(neigh);
 932			notify = 1;
 933			next = neigh->confirmed + neigh->parms->reachable_time;
 934		} else {
 935			NEIGH_PRINTK2("neigh %p is probed.\n", neigh);
 936			neigh->nud_state = NUD_PROBE;
 937			neigh->updated = jiffies;
 938			atomic_set(&neigh->probes, 0);
 939			next = now + neigh->parms->retrans_time;
 
 
 940		}
 941	} else {
 942		/* NUD_PROBE|NUD_INCOMPLETE */
 943		next = now + neigh->parms->retrans_time;
 944	}
 945
 946	if ((neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) &&
 947	    atomic_read(&neigh->probes) >= neigh_max_probes(neigh)) {
 948		neigh->nud_state = NUD_FAILED;
 949		notify = 1;
 950		neigh_invalidate(neigh);
 
 951	}
 952
 953	if (neigh->nud_state & NUD_IN_TIMER) {
 954		if (time_before(next, jiffies + HZ/2))
 955			next = jiffies + HZ/2;
 956		if (!mod_timer(&neigh->timer, next))
 957			neigh_hold(neigh);
 958	}
 959	if (neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) {
 960		neigh_probe(neigh);
 961	} else {
 962out:
 963		write_unlock(&neigh->lock);
 964	}
 965
 966	if (notify)
 967		neigh_update_notify(neigh);
 
 
 968
 969	neigh_release(neigh);
 970}
 971
 972int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 973{
 974	int rc;
 975	bool immediate_probe = false;
 976
 977	write_lock_bh(&neigh->lock);
 978
 979	rc = 0;
 980	if (neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE))
 981		goto out_unlock_bh;
 
 
 982
 983	if (!(neigh->nud_state & (NUD_STALE | NUD_INCOMPLETE))) {
 984		if (neigh->parms->mcast_probes + neigh->parms->app_probes) {
 
 985			unsigned long next, now = jiffies;
 986
 987			atomic_set(&neigh->probes, neigh->parms->ucast_probes);
 
 
 988			neigh->nud_state     = NUD_INCOMPLETE;
 989			neigh->updated = now;
 990			next = now + max(neigh->parms->retrans_time, HZ/2);
 
 991			neigh_add_timer(neigh, next);
 992			immediate_probe = true;
 993		} else {
 994			neigh->nud_state = NUD_FAILED;
 995			neigh->updated = jiffies;
 996			write_unlock_bh(&neigh->lock);
 997
 998			kfree_skb(skb);
 999			return 1;
1000		}
1001	} else if (neigh->nud_state & NUD_STALE) {
1002		NEIGH_PRINTK2("neigh %p is delayed.\n", neigh);
 
1003		neigh->nud_state = NUD_DELAY;
1004		neigh->updated = jiffies;
1005		neigh_add_timer(neigh,
1006				jiffies + neigh->parms->delay_probe_time);
1007	}
1008
1009	if (neigh->nud_state == NUD_INCOMPLETE) {
1010		if (skb) {
1011			while (neigh->arp_queue_len_bytes + skb->truesize >
1012			       neigh->parms->queue_len_bytes) {
1013				struct sk_buff *buff;
1014
1015				buff = __skb_dequeue(&neigh->arp_queue);
1016				if (!buff)
1017					break;
1018				neigh->arp_queue_len_bytes -= buff->truesize;
1019				kfree_skb(buff);
1020				NEIGH_CACHE_STAT_INC(neigh->tbl, unres_discards);
1021			}
1022			skb_dst_force(skb);
1023			__skb_queue_tail(&neigh->arp_queue, skb);
1024			neigh->arp_queue_len_bytes += skb->truesize;
1025		}
1026		rc = 1;
1027	}
1028out_unlock_bh:
1029	if (immediate_probe)
1030		neigh_probe(neigh);
1031	else
1032		write_unlock(&neigh->lock);
1033	local_bh_enable();
 
1034	return rc;
 
 
 
 
 
 
 
 
1035}
1036EXPORT_SYMBOL(__neigh_event_send);
1037
1038static void neigh_update_hhs(struct neighbour *neigh)
1039{
1040	struct hh_cache *hh;
1041	void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *)
1042		= NULL;
1043
1044	if (neigh->dev->header_ops)
1045		update = neigh->dev->header_ops->cache_update;
1046
1047	if (update) {
1048		hh = &neigh->hh;
1049		if (hh->hh_len) {
1050			write_seqlock_bh(&hh->hh_lock);
1051			update(hh, neigh->dev, neigh->ha);
1052			write_sequnlock_bh(&hh->hh_lock);
1053		}
1054	}
1055}
1056
1057
1058
1059/* Generic update routine.
1060   -- lladdr is new lladdr or NULL, if it is not supplied.
1061   -- new    is new state.
1062   -- flags
1063	NEIGH_UPDATE_F_OVERRIDE allows to override existing lladdr,
1064				if it is different.
1065	NEIGH_UPDATE_F_WEAK_OVERRIDE will suspect existing "connected"
1066				lladdr instead of overriding it
1067				if it is different.
1068				It also allows to retain current state
1069				if lladdr is unchanged.
1070	NEIGH_UPDATE_F_ADMIN	means that the change is administrative.
1071
1072	NEIGH_UPDATE_F_OVERRIDE_ISROUTER allows to override existing
1073				NTF_ROUTER flag.
1074	NEIGH_UPDATE_F_ISROUTER	indicates if the neighbour is known as
1075				a router.
1076
1077   Caller MUST hold reference count on the entry.
1078 */
1079
1080int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
1081		 u32 flags)
 
1082{
 
1083	u8 old;
1084	int err;
1085	int notify = 0;
1086	struct net_device *dev;
1087	int update_isrouter = 0;
1088
 
 
1089	write_lock_bh(&neigh->lock);
1090
1091	dev    = neigh->dev;
1092	old    = neigh->nud_state;
1093	err    = -EPERM;
1094
 
 
 
 
 
1095	if (!(flags & NEIGH_UPDATE_F_ADMIN) &&
1096	    (old & (NUD_NOARP | NUD_PERMANENT)))
1097		goto out;
1098
 
 
1099	if (!(new & NUD_VALID)) {
1100		neigh_del_timer(neigh);
1101		if (old & NUD_CONNECTED)
1102			neigh_suspect(neigh);
1103		neigh->nud_state = new;
1104		err = 0;
1105		notify = old & NUD_VALID;
1106		if ((old & (NUD_INCOMPLETE | NUD_PROBE)) &&
1107		    (new & NUD_FAILED)) {
1108			neigh_invalidate(neigh);
1109			notify = 1;
1110		}
1111		goto out;
1112	}
1113
1114	/* Compare new lladdr with cached one */
1115	if (!dev->addr_len) {
1116		/* First case: device needs no address. */
1117		lladdr = neigh->ha;
1118	} else if (lladdr) {
1119		/* The second case: if something is already cached
1120		   and a new address is proposed:
1121		   - compare new & old
1122		   - if they are different, check override flag
1123		 */
1124		if ((old & NUD_VALID) &&
1125		    !memcmp(lladdr, neigh->ha, dev->addr_len))
1126			lladdr = neigh->ha;
1127	} else {
1128		/* No address is supplied; if we know something,
1129		   use it, otherwise discard the request.
1130		 */
1131		err = -EINVAL;
1132		if (!(old & NUD_VALID))
 
1133			goto out;
 
1134		lladdr = neigh->ha;
1135	}
1136
 
 
 
1137	if (new & NUD_CONNECTED)
1138		neigh->confirmed = jiffies;
1139	neigh->updated = jiffies;
1140
1141	/* If entry was valid and address is not changed,
1142	   do not change entry state, if new one is STALE.
1143	 */
1144	err = 0;
1145	update_isrouter = flags & NEIGH_UPDATE_F_OVERRIDE_ISROUTER;
1146	if (old & NUD_VALID) {
1147		if (lladdr != neigh->ha && !(flags & NEIGH_UPDATE_F_OVERRIDE)) {
1148			update_isrouter = 0;
1149			if ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) &&
1150			    (old & NUD_CONNECTED)) {
1151				lladdr = neigh->ha;
1152				new = NUD_STALE;
1153			} else
1154				goto out;
1155		} else {
1156			if (lladdr == neigh->ha && new == NUD_STALE &&
1157			    ((flags & NEIGH_UPDATE_F_WEAK_OVERRIDE) ||
1158			     (old & NUD_CONNECTED))
1159			    )
1160				new = old;
1161		}
1162	}
1163
 
 
 
 
 
 
 
1164	if (new != old) {
1165		neigh_del_timer(neigh);
 
 
1166		if (new & NUD_IN_TIMER)
1167			neigh_add_timer(neigh, (jiffies +
1168						((new & NUD_REACHABLE) ?
1169						 neigh->parms->reachable_time :
1170						 0)));
1171		neigh->nud_state = new;
 
1172	}
1173
1174	if (lladdr != neigh->ha) {
1175		write_seqlock(&neigh->ha_lock);
1176		memcpy(&neigh->ha, lladdr, dev->addr_len);
1177		write_sequnlock(&neigh->ha_lock);
1178		neigh_update_hhs(neigh);
1179		if (!(new & NUD_CONNECTED))
1180			neigh->confirmed = jiffies -
1181				      (neigh->parms->base_reachable_time << 1);
1182		notify = 1;
1183	}
1184	if (new == old)
1185		goto out;
1186	if (new & NUD_CONNECTED)
1187		neigh_connect(neigh);
1188	else
1189		neigh_suspect(neigh);
1190	if (!(old & NUD_VALID)) {
1191		struct sk_buff *skb;
1192
1193		/* Again: avoid dead loop if something went wrong */
1194
1195		while (neigh->nud_state & NUD_VALID &&
1196		       (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {
1197			struct dst_entry *dst = skb_dst(skb);
1198			struct neighbour *n2, *n1 = neigh;
1199			write_unlock_bh(&neigh->lock);
1200
1201			rcu_read_lock();
1202			/* On shaper/eql skb->dst->neighbour != neigh :( */
1203			if (dst && (n2 = dst_get_neighbour_noref(dst)) != NULL)
1204				n1 = n2;
 
 
 
 
 
 
 
 
 
 
 
1205			n1->output(n1, skb);
 
 
1206			rcu_read_unlock();
1207
1208			write_lock_bh(&neigh->lock);
1209		}
1210		skb_queue_purge(&neigh->arp_queue);
1211		neigh->arp_queue_len_bytes = 0;
1212	}
1213out:
1214	if (update_isrouter) {
1215		neigh->flags = (flags & NEIGH_UPDATE_F_ISROUTER) ?
1216			(neigh->flags | NTF_ROUTER) :
1217			(neigh->flags & ~NTF_ROUTER);
1218	}
1219	write_unlock_bh(&neigh->lock);
1220
 
 
 
1221	if (notify)
1222		neigh_update_notify(neigh);
 
 
1223
1224	return err;
1225}
 
 
 
 
 
 
1226EXPORT_SYMBOL(neigh_update);
1227
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1228struct neighbour *neigh_event_ns(struct neigh_table *tbl,
1229				 u8 *lladdr, void *saddr,
1230				 struct net_device *dev)
1231{
1232	struct neighbour *neigh = __neigh_lookup(tbl, saddr, dev,
1233						 lladdr || !dev->addr_len);
1234	if (neigh)
1235		neigh_update(neigh, lladdr, NUD_STALE,
1236			     NEIGH_UPDATE_F_OVERRIDE);
1237	return neigh;
1238}
1239EXPORT_SYMBOL(neigh_event_ns);
1240
1241/* called with read_lock_bh(&n->lock); */
1242static void neigh_hh_init(struct neighbour *n, struct dst_entry *dst)
1243{
1244	struct net_device *dev = dst->dev;
1245	__be16 prot = dst->ops->protocol;
1246	struct hh_cache	*hh = &n->hh;
1247
1248	write_lock_bh(&n->lock);
1249
1250	/* Only one thread can come in here and initialize the
1251	 * hh_cache entry.
1252	 */
1253	if (!hh->hh_len)
1254		dev->header_ops->cache(n, hh, prot);
1255
1256	write_unlock_bh(&n->lock);
1257}
1258
1259/* This function can be used in contexts, where only old dev_queue_xmit
1260 * worked, f.e. if you want to override normal output path (eql, shaper),
1261 * but resolution is not made yet.
1262 */
1263
1264int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb)
1265{
1266	struct net_device *dev = skb->dev;
1267
1268	__skb_pull(skb, skb_network_offset(skb));
1269
1270	if (dev_hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
1271			    skb->len) < 0 &&
1272	    dev->header_ops->rebuild(skb))
1273		return 0;
1274
1275	return dev_queue_xmit(skb);
1276}
1277EXPORT_SYMBOL(neigh_compat_output);
1278
1279/* Slow and careful. */
1280
1281int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb)
1282{
1283	struct dst_entry *dst = skb_dst(skb);
1284	int rc = 0;
1285
1286	if (!dst)
1287		goto discard;
1288
1289	__skb_pull(skb, skb_network_offset(skb));
1290
1291	if (!neigh_event_send(neigh, skb)) {
1292		int err;
1293		struct net_device *dev = neigh->dev;
1294		unsigned int seq;
1295
1296		if (dev->header_ops->cache && !neigh->hh.hh_len)
1297			neigh_hh_init(neigh, dst);
1298
1299		do {
 
1300			seq = read_seqbegin(&neigh->ha_lock);
1301			err = dev_hard_header(skb, dev, ntohs(skb->protocol),
1302					      neigh->ha, NULL, skb->len);
1303		} while (read_seqretry(&neigh->ha_lock, seq));
1304
1305		if (err >= 0)
1306			rc = dev_queue_xmit(skb);
1307		else
1308			goto out_kfree_skb;
1309	}
1310out:
1311	return rc;
1312discard:
1313	NEIGH_PRINTK1("neigh_resolve_output: dst=%p neigh=%p\n",
1314		      dst, neigh);
1315out_kfree_skb:
1316	rc = -EINVAL;
1317	kfree_skb(skb);
1318	goto out;
1319}
1320EXPORT_SYMBOL(neigh_resolve_output);
1321
1322/* As fast as possible without hh cache */
1323
1324int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb)
1325{
1326	struct net_device *dev = neigh->dev;
1327	unsigned int seq;
1328	int err;
1329
1330	__skb_pull(skb, skb_network_offset(skb));
1331
1332	do {
 
1333		seq = read_seqbegin(&neigh->ha_lock);
1334		err = dev_hard_header(skb, dev, ntohs(skb->protocol),
1335				      neigh->ha, NULL, skb->len);
1336	} while (read_seqretry(&neigh->ha_lock, seq));
1337
1338	if (err >= 0)
1339		err = dev_queue_xmit(skb);
1340	else {
1341		err = -EINVAL;
1342		kfree_skb(skb);
1343	}
1344	return err;
1345}
1346EXPORT_SYMBOL(neigh_connected_output);
1347
1348int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb)
1349{
1350	return dev_queue_xmit(skb);
1351}
1352EXPORT_SYMBOL(neigh_direct_output);
1353
1354static void neigh_proxy_process(unsigned long arg)
1355{
1356	struct neigh_table *tbl = (struct neigh_table *)arg;
1357	long sched_next = 0;
1358	unsigned long now = jiffies;
1359	struct sk_buff *skb, *n;
1360
1361	spin_lock(&tbl->proxy_queue.lock);
1362
1363	skb_queue_walk_safe(&tbl->proxy_queue, skb, n) {
1364		long tdif = NEIGH_CB(skb)->sched_next - now;
1365
1366		if (tdif <= 0) {
1367			struct net_device *dev = skb->dev;
1368
1369			__skb_unlink(skb, &tbl->proxy_queue);
1370			if (tbl->proxy_redo && netif_running(dev)) {
1371				rcu_read_lock();
1372				tbl->proxy_redo(skb);
1373				rcu_read_unlock();
1374			} else {
1375				kfree_skb(skb);
1376			}
1377
1378			dev_put(dev);
1379		} else if (!sched_next || tdif < sched_next)
1380			sched_next = tdif;
1381	}
1382	del_timer(&tbl->proxy_timer);
1383	if (sched_next)
1384		mod_timer(&tbl->proxy_timer, jiffies + sched_next);
1385	spin_unlock(&tbl->proxy_queue.lock);
1386}
1387
1388void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
1389		    struct sk_buff *skb)
1390{
1391	unsigned long now = jiffies;
1392	unsigned long sched_next = now + (net_random() % p->proxy_delay);
1393
1394	if (tbl->proxy_queue.qlen > p->proxy_qlen) {
1395		kfree_skb(skb);
1396		return;
1397	}
1398
1399	NEIGH_CB(skb)->sched_next = sched_next;
1400	NEIGH_CB(skb)->flags |= LOCALLY_ENQUEUED;
1401
1402	spin_lock(&tbl->proxy_queue.lock);
1403	if (del_timer(&tbl->proxy_timer)) {
1404		if (time_before(tbl->proxy_timer.expires, sched_next))
1405			sched_next = tbl->proxy_timer.expires;
1406	}
1407	skb_dst_drop(skb);
1408	dev_hold(skb->dev);
1409	__skb_queue_tail(&tbl->proxy_queue, skb);
1410	mod_timer(&tbl->proxy_timer, sched_next);
1411	spin_unlock(&tbl->proxy_queue.lock);
1412}
1413EXPORT_SYMBOL(pneigh_enqueue);
1414
1415static inline struct neigh_parms *lookup_neigh_parms(struct neigh_table *tbl,
1416						      struct net *net, int ifindex)
1417{
1418	struct neigh_parms *p;
1419
1420	for (p = &tbl->parms; p; p = p->next) {
1421		if ((p->dev && p->dev->ifindex == ifindex && net_eq(neigh_parms_net(p), net)) ||
1422		    (!p->dev && !ifindex))
1423			return p;
1424	}
1425
1426	return NULL;
1427}
1428
1429struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
1430				      struct neigh_table *tbl)
1431{
1432	struct neigh_parms *p, *ref;
1433	struct net *net = dev_net(dev);
1434	const struct net_device_ops *ops = dev->netdev_ops;
1435
1436	ref = lookup_neigh_parms(tbl, net, 0);
1437	if (!ref)
1438		return NULL;
1439
1440	p = kmemdup(ref, sizeof(*p), GFP_KERNEL);
1441	if (p) {
1442		p->tbl		  = tbl;
1443		atomic_set(&p->refcnt, 1);
1444		p->reachable_time =
1445				neigh_rand_reach_time(p->base_reachable_time);
 
 
 
 
1446
1447		if (ops->ndo_neigh_setup && ops->ndo_neigh_setup(dev, p)) {
 
1448			kfree(p);
1449			return NULL;
1450		}
1451
1452		dev_hold(dev);
1453		p->dev = dev;
1454		write_pnet(&p->net, hold_net(net));
1455		p->sysctl_table = NULL;
1456		write_lock_bh(&tbl->lock);
1457		p->next		= tbl->parms.next;
1458		tbl->parms.next = p;
1459		write_unlock_bh(&tbl->lock);
 
 
1460	}
1461	return p;
1462}
1463EXPORT_SYMBOL(neigh_parms_alloc);
1464
1465static void neigh_rcu_free_parms(struct rcu_head *head)
1466{
1467	struct neigh_parms *parms =
1468		container_of(head, struct neigh_parms, rcu_head);
1469
1470	neigh_parms_put(parms);
1471}
1472
1473void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
1474{
1475	struct neigh_parms **p;
1476
1477	if (!parms || parms == &tbl->parms)
1478		return;
1479	write_lock_bh(&tbl->lock);
1480	for (p = &tbl->parms.next; *p; p = &(*p)->next) {
1481		if (*p == parms) {
1482			*p = parms->next;
1483			parms->dead = 1;
1484			write_unlock_bh(&tbl->lock);
1485			if (parms->dev)
1486				dev_put(parms->dev);
1487			call_rcu(&parms->rcu_head, neigh_rcu_free_parms);
1488			return;
1489		}
1490	}
1491	write_unlock_bh(&tbl->lock);
1492	NEIGH_PRINTK1("neigh_parms_release: not found\n");
 
 
1493}
1494EXPORT_SYMBOL(neigh_parms_release);
1495
1496static void neigh_parms_destroy(struct neigh_parms *parms)
1497{
1498	release_net(neigh_parms_net(parms));
1499	kfree(parms);
1500}
1501
1502static struct lock_class_key neigh_table_proxy_queue_class;
1503
1504static void neigh_table_init_no_netlink(struct neigh_table *tbl)
 
 
1505{
1506	unsigned long now = jiffies;
1507	unsigned long phsize;
1508
 
 
 
1509	write_pnet(&tbl->parms.net, &init_net);
1510	atomic_set(&tbl->parms.refcnt, 1);
1511	tbl->parms.reachable_time =
1512			  neigh_rand_reach_time(tbl->parms.base_reachable_time);
1513
1514	tbl->stats = alloc_percpu(struct neigh_statistics);
1515	if (!tbl->stats)
1516		panic("cannot create neighbour cache statistics");
1517
1518#ifdef CONFIG_PROC_FS
1519	if (!proc_create_data(tbl->id, 0, init_net.proc_net_stat,
1520			      &neigh_stat_seq_fops, tbl))
1521		panic("cannot create neighbour proc dir entry");
1522#endif
1523
1524	RCU_INIT_POINTER(tbl->nht, neigh_hash_alloc(3));
1525
1526	phsize = (PNEIGH_HASHMASK + 1) * sizeof(struct pneigh_entry *);
1527	tbl->phash_buckets = kzalloc(phsize, GFP_KERNEL);
1528
1529	if (!tbl->nht || !tbl->phash_buckets)
1530		panic("cannot allocate neighbour cache hashes");
1531
 
 
 
 
 
 
1532	rwlock_init(&tbl->lock);
1533	INIT_DELAYED_WORK_DEFERRABLE(&tbl->gc_work, neigh_periodic_work);
1534	schedule_delayed_work(&tbl->gc_work, tbl->parms.reachable_time);
1535	setup_timer(&tbl->proxy_timer, neigh_proxy_process, (unsigned long)tbl);
 
1536	skb_queue_head_init_class(&tbl->proxy_queue,
1537			&neigh_table_proxy_queue_class);
1538
1539	tbl->last_flush = now;
1540	tbl->last_rand	= now + tbl->parms.reachable_time * 20;
1541}
1542
1543void neigh_table_init(struct neigh_table *tbl)
1544{
1545	struct neigh_table *tmp;
1546
1547	neigh_table_init_no_netlink(tbl);
1548	write_lock(&neigh_tbl_lock);
1549	for (tmp = neigh_tables; tmp; tmp = tmp->next) {
1550		if (tmp->family == tbl->family)
1551			break;
1552	}
1553	tbl->next	= neigh_tables;
1554	neigh_tables	= tbl;
1555	write_unlock(&neigh_tbl_lock);
1556
1557	if (unlikely(tmp)) {
1558		pr_err("Registering multiple tables for family %d\n",
1559		       tbl->family);
1560		dump_stack();
1561	}
1562}
1563EXPORT_SYMBOL(neigh_table_init);
1564
1565int neigh_table_clear(struct neigh_table *tbl)
1566{
1567	struct neigh_table **tp;
1568
1569	/* It is not clean... Fix it to unload IPv6 module safely */
1570	cancel_delayed_work_sync(&tbl->gc_work);
1571	del_timer_sync(&tbl->proxy_timer);
1572	pneigh_queue_purge(&tbl->proxy_queue);
1573	neigh_ifdown(tbl, NULL);
1574	if (atomic_read(&tbl->entries))
1575		pr_crit("neighbour leakage\n");
1576	write_lock(&neigh_tbl_lock);
1577	for (tp = &neigh_tables; *tp; tp = &(*tp)->next) {
1578		if (*tp == tbl) {
1579			*tp = tbl->next;
1580			break;
1581		}
1582	}
1583	write_unlock(&neigh_tbl_lock);
1584
1585	call_rcu(&rcu_dereference_protected(tbl->nht, 1)->rcu,
1586		 neigh_hash_free_rcu);
1587	tbl->nht = NULL;
1588
1589	kfree(tbl->phash_buckets);
1590	tbl->phash_buckets = NULL;
1591
1592	remove_proc_entry(tbl->id, init_net.proc_net_stat);
1593
1594	free_percpu(tbl->stats);
1595	tbl->stats = NULL;
1596
1597	return 0;
1598}
1599EXPORT_SYMBOL(neigh_table_clear);
1600
1601static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1602{
1603	struct net *net = sock_net(skb->sk);
1604	struct ndmsg *ndm;
1605	struct nlattr *dst_attr;
1606	struct neigh_table *tbl;
 
1607	struct net_device *dev = NULL;
1608	int err = -EINVAL;
1609
1610	ASSERT_RTNL();
1611	if (nlmsg_len(nlh) < sizeof(*ndm))
1612		goto out;
1613
1614	dst_attr = nlmsg_find_attr(nlh, sizeof(*ndm), NDA_DST);
1615	if (dst_attr == NULL)
 
1616		goto out;
 
1617
1618	ndm = nlmsg_data(nlh);
1619	if (ndm->ndm_ifindex) {
1620		dev = __dev_get_by_index(net, ndm->ndm_ifindex);
1621		if (dev == NULL) {
1622			err = -ENODEV;
1623			goto out;
1624		}
1625	}
1626
1627	read_lock(&neigh_tbl_lock);
1628	for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1629		struct neighbour *neigh;
1630
1631		if (tbl->family != ndm->ndm_family)
1632			continue;
1633		read_unlock(&neigh_tbl_lock);
 
1634
1635		if (nla_len(dst_attr) < tbl->key_len)
1636			goto out;
 
 
1637
1638		if (ndm->ndm_flags & NTF_PROXY) {
1639			err = pneigh_delete(tbl, net, nla_data(dst_attr), dev);
1640			goto out;
1641		}
1642
1643		if (dev == NULL)
1644			goto out;
1645
1646		neigh = neigh_lookup(tbl, nla_data(dst_attr), dev);
1647		if (neigh == NULL) {
1648			err = -ENOENT;
1649			goto out;
1650		}
1651
1652		err = neigh_update(neigh, NULL, NUD_FAILED,
1653				   NEIGH_UPDATE_F_OVERRIDE |
1654				   NEIGH_UPDATE_F_ADMIN);
1655		neigh_release(neigh);
1656		goto out;
1657	}
1658	read_unlock(&neigh_tbl_lock);
1659	err = -EAFNOSUPPORT;
 
 
 
 
 
 
1660
1661out:
1662	return err;
1663}
1664
1665static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 
1666{
 
 
1667	struct net *net = sock_net(skb->sk);
1668	struct ndmsg *ndm;
1669	struct nlattr *tb[NDA_MAX+1];
1670	struct neigh_table *tbl;
1671	struct net_device *dev = NULL;
 
 
 
1672	int err;
1673
1674	ASSERT_RTNL();
1675	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
 
1676	if (err < 0)
1677		goto out;
1678
1679	err = -EINVAL;
1680	if (tb[NDA_DST] == NULL)
 
1681		goto out;
 
1682
1683	ndm = nlmsg_data(nlh);
1684	if (ndm->ndm_ifindex) {
1685		dev = __dev_get_by_index(net, ndm->ndm_ifindex);
1686		if (dev == NULL) {
1687			err = -ENODEV;
1688			goto out;
1689		}
1690
1691		if (tb[NDA_LLADDR] && nla_len(tb[NDA_LLADDR]) < dev->addr_len)
 
1692			goto out;
 
 
 
 
 
 
 
 
 
 
1693	}
1694
1695	read_lock(&neigh_tbl_lock);
1696	for (tbl = neigh_tables; tbl; tbl = tbl->next) {
1697		int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE;
1698		struct neighbour *neigh;
1699		void *dst, *lladdr;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1700
1701		if (tbl->family != ndm->ndm_family)
1702			continue;
1703		read_unlock(&neigh_tbl_lock);
 
1704
1705		if (nla_len(tb[NDA_DST]) < tbl->key_len)
1706			goto out;
1707		dst = nla_data(tb[NDA_DST]);
1708		lladdr = tb[NDA_LLADDR] ? nla_data(tb[NDA_LLADDR]) : NULL;
1709
1710		if (ndm->ndm_flags & NTF_PROXY) {
1711			struct pneigh_entry *pn;
 
1712
1713			err = -ENOBUFS;
1714			pn = pneigh_lookup(tbl, net, dst, dev, 1);
1715			if (pn) {
1716				pn->flags = ndm->ndm_flags;
1717				err = 0;
1718			}
1719			goto out;
1720		}
1721
1722		if (dev == NULL)
 
 
 
 
1723			goto out;
 
 
 
 
 
 
 
1724
1725		neigh = neigh_lookup(tbl, dst, dev);
1726		if (neigh == NULL) {
1727			if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
1728				err = -ENOENT;
1729				goto out;
1730			}
 
 
 
 
1731
1732			neigh = __neigh_lookup_errno(tbl, dst, dev);
1733			if (IS_ERR(neigh)) {
1734				err = PTR_ERR(neigh);
1735				goto out;
1736			}
1737		} else {
1738			if (nlh->nlmsg_flags & NLM_F_EXCL) {
1739				err = -EEXIST;
1740				neigh_release(neigh);
1741				goto out;
1742			}
1743
1744			if (!(nlh->nlmsg_flags & NLM_F_REPLACE))
1745				flags &= ~NEIGH_UPDATE_F_OVERRIDE;
1746		}
 
 
 
1747
1748		if (ndm->ndm_flags & NTF_USE) {
1749			neigh_event_send(neigh, NULL);
1750			err = 0;
1751		} else
1752			err = neigh_update(neigh, lladdr, ndm->ndm_state, flags);
1753		neigh_release(neigh);
1754		goto out;
1755	}
1756
1757	read_unlock(&neigh_tbl_lock);
1758	err = -EAFNOSUPPORT;
1759out:
1760	return err;
1761}
1762
1763static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms)
1764{
1765	struct nlattr *nest;
1766
1767	nest = nla_nest_start(skb, NDTA_PARMS);
1768	if (nest == NULL)
1769		return -ENOBUFS;
1770
1771	if ((parms->dev &&
1772	     nla_put_u32(skb, NDTPA_IFINDEX, parms->dev->ifindex)) ||
1773	    nla_put_u32(skb, NDTPA_REFCNT, atomic_read(&parms->refcnt)) ||
1774	    nla_put_u32(skb, NDTPA_QUEUE_LENBYTES, parms->queue_len_bytes) ||
 
1775	    /* approximative value for deprecated QUEUE_LEN (in packets) */
1776	    nla_put_u32(skb, NDTPA_QUEUE_LEN,
1777			DIV_ROUND_UP(parms->queue_len_bytes,
1778				     SKB_TRUESIZE(ETH_FRAME_LEN))) ||
1779	    nla_put_u32(skb, NDTPA_PROXY_QLEN, parms->proxy_qlen) ||
1780	    nla_put_u32(skb, NDTPA_APP_PROBES, parms->app_probes) ||
1781	    nla_put_u32(skb, NDTPA_UCAST_PROBES, parms->ucast_probes) ||
1782	    nla_put_u32(skb, NDTPA_MCAST_PROBES, parms->mcast_probes) ||
1783	    nla_put_msecs(skb, NDTPA_REACHABLE_TIME, parms->reachable_time) ||
 
 
 
 
1784	    nla_put_msecs(skb, NDTPA_BASE_REACHABLE_TIME,
1785			  parms->base_reachable_time) ||
1786	    nla_put_msecs(skb, NDTPA_GC_STALETIME, parms->gc_staletime) ||
 
1787	    nla_put_msecs(skb, NDTPA_DELAY_PROBE_TIME,
1788			  parms->delay_probe_time) ||
1789	    nla_put_msecs(skb, NDTPA_RETRANS_TIME, parms->retrans_time) ||
1790	    nla_put_msecs(skb, NDTPA_ANYCAST_DELAY, parms->anycast_delay) ||
1791	    nla_put_msecs(skb, NDTPA_PROXY_DELAY, parms->proxy_delay) ||
1792	    nla_put_msecs(skb, NDTPA_LOCKTIME, parms->locktime))
 
 
 
 
1793		goto nla_put_failure;
1794	return nla_nest_end(skb, nest);
1795
1796nla_put_failure:
1797	nla_nest_cancel(skb, nest);
1798	return -EMSGSIZE;
1799}
1800
1801static int neightbl_fill_info(struct sk_buff *skb, struct neigh_table *tbl,
1802			      u32 pid, u32 seq, int type, int flags)
1803{
1804	struct nlmsghdr *nlh;
1805	struct ndtmsg *ndtmsg;
1806
1807	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
1808	if (nlh == NULL)
1809		return -EMSGSIZE;
1810
1811	ndtmsg = nlmsg_data(nlh);
1812
1813	read_lock_bh(&tbl->lock);
1814	ndtmsg->ndtm_family = tbl->family;
1815	ndtmsg->ndtm_pad1   = 0;
1816	ndtmsg->ndtm_pad2   = 0;
1817
1818	if (nla_put_string(skb, NDTA_NAME, tbl->id) ||
1819	    nla_put_msecs(skb, NDTA_GC_INTERVAL, tbl->gc_interval) ||
1820	    nla_put_u32(skb, NDTA_THRESH1, tbl->gc_thresh1) ||
1821	    nla_put_u32(skb, NDTA_THRESH2, tbl->gc_thresh2) ||
1822	    nla_put_u32(skb, NDTA_THRESH3, tbl->gc_thresh3))
1823		goto nla_put_failure;
1824	{
1825		unsigned long now = jiffies;
1826		unsigned int flush_delta = now - tbl->last_flush;
1827		unsigned int rand_delta = now - tbl->last_rand;
1828		struct neigh_hash_table *nht;
1829		struct ndt_config ndc = {
1830			.ndtc_key_len		= tbl->key_len,
1831			.ndtc_entry_size	= tbl->entry_size,
1832			.ndtc_entries		= atomic_read(&tbl->entries),
1833			.ndtc_last_flush	= jiffies_to_msecs(flush_delta),
1834			.ndtc_last_rand		= jiffies_to_msecs(rand_delta),
1835			.ndtc_proxy_qlen	= tbl->proxy_queue.qlen,
1836		};
1837
1838		rcu_read_lock_bh();
1839		nht = rcu_dereference_bh(tbl->nht);
1840		ndc.ndtc_hash_rnd = nht->hash_rnd[0];
1841		ndc.ndtc_hash_mask = ((1 << nht->hash_shift) - 1);
1842		rcu_read_unlock_bh();
1843
1844		if (nla_put(skb, NDTA_CONFIG, sizeof(ndc), &ndc))
1845			goto nla_put_failure;
1846	}
1847
1848	{
1849		int cpu;
1850		struct ndt_stats ndst;
1851
1852		memset(&ndst, 0, sizeof(ndst));
1853
1854		for_each_possible_cpu(cpu) {
1855			struct neigh_statistics	*st;
1856
1857			st = per_cpu_ptr(tbl->stats, cpu);
1858			ndst.ndts_allocs		+= st->allocs;
1859			ndst.ndts_destroys		+= st->destroys;
1860			ndst.ndts_hash_grows		+= st->hash_grows;
1861			ndst.ndts_res_failed		+= st->res_failed;
1862			ndst.ndts_lookups		+= st->lookups;
1863			ndst.ndts_hits			+= st->hits;
1864			ndst.ndts_rcv_probes_mcast	+= st->rcv_probes_mcast;
1865			ndst.ndts_rcv_probes_ucast	+= st->rcv_probes_ucast;
1866			ndst.ndts_periodic_gc_runs	+= st->periodic_gc_runs;
1867			ndst.ndts_forced_gc_runs	+= st->forced_gc_runs;
 
1868		}
1869
1870		if (nla_put(skb, NDTA_STATS, sizeof(ndst), &ndst))
 
1871			goto nla_put_failure;
1872	}
1873
1874	BUG_ON(tbl->parms.dev);
1875	if (neightbl_fill_parms(skb, &tbl->parms) < 0)
1876		goto nla_put_failure;
1877
1878	read_unlock_bh(&tbl->lock);
1879	return nlmsg_end(skb, nlh);
 
1880
1881nla_put_failure:
1882	read_unlock_bh(&tbl->lock);
1883	nlmsg_cancel(skb, nlh);
1884	return -EMSGSIZE;
1885}
1886
1887static int neightbl_fill_param_info(struct sk_buff *skb,
1888				    struct neigh_table *tbl,
1889				    struct neigh_parms *parms,
1890				    u32 pid, u32 seq, int type,
1891				    unsigned int flags)
1892{
1893	struct ndtmsg *ndtmsg;
1894	struct nlmsghdr *nlh;
1895
1896	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
1897	if (nlh == NULL)
1898		return -EMSGSIZE;
1899
1900	ndtmsg = nlmsg_data(nlh);
1901
1902	read_lock_bh(&tbl->lock);
1903	ndtmsg->ndtm_family = tbl->family;
1904	ndtmsg->ndtm_pad1   = 0;
1905	ndtmsg->ndtm_pad2   = 0;
1906
1907	if (nla_put_string(skb, NDTA_NAME, tbl->id) < 0 ||
1908	    neightbl_fill_parms(skb, parms) < 0)
1909		goto errout;
1910
1911	read_unlock_bh(&tbl->lock);
1912	return nlmsg_end(skb, nlh);
 
1913errout:
1914	read_unlock_bh(&tbl->lock);
1915	nlmsg_cancel(skb, nlh);
1916	return -EMSGSIZE;
1917}
1918
1919static const struct nla_policy nl_neightbl_policy[NDTA_MAX+1] = {
1920	[NDTA_NAME]		= { .type = NLA_STRING },
1921	[NDTA_THRESH1]		= { .type = NLA_U32 },
1922	[NDTA_THRESH2]		= { .type = NLA_U32 },
1923	[NDTA_THRESH3]		= { .type = NLA_U32 },
1924	[NDTA_GC_INTERVAL]	= { .type = NLA_U64 },
1925	[NDTA_PARMS]		= { .type = NLA_NESTED },
1926};
1927
1928static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
1929	[NDTPA_IFINDEX]			= { .type = NLA_U32 },
1930	[NDTPA_QUEUE_LEN]		= { .type = NLA_U32 },
1931	[NDTPA_PROXY_QLEN]		= { .type = NLA_U32 },
1932	[NDTPA_APP_PROBES]		= { .type = NLA_U32 },
1933	[NDTPA_UCAST_PROBES]		= { .type = NLA_U32 },
1934	[NDTPA_MCAST_PROBES]		= { .type = NLA_U32 },
 
1935	[NDTPA_BASE_REACHABLE_TIME]	= { .type = NLA_U64 },
1936	[NDTPA_GC_STALETIME]		= { .type = NLA_U64 },
1937	[NDTPA_DELAY_PROBE_TIME]	= { .type = NLA_U64 },
1938	[NDTPA_RETRANS_TIME]		= { .type = NLA_U64 },
1939	[NDTPA_ANYCAST_DELAY]		= { .type = NLA_U64 },
1940	[NDTPA_PROXY_DELAY]		= { .type = NLA_U64 },
1941	[NDTPA_LOCKTIME]		= { .type = NLA_U64 },
1942};
1943
1944static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 
1945{
1946	struct net *net = sock_net(skb->sk);
1947	struct neigh_table *tbl;
1948	struct ndtmsg *ndtmsg;
1949	struct nlattr *tb[NDTA_MAX+1];
1950	int err;
 
1951
1952	err = nlmsg_parse(nlh, sizeof(*ndtmsg), tb, NDTA_MAX,
1953			  nl_neightbl_policy);
1954	if (err < 0)
1955		goto errout;
1956
1957	if (tb[NDTA_NAME] == NULL) {
1958		err = -EINVAL;
1959		goto errout;
1960	}
1961
1962	ndtmsg = nlmsg_data(nlh);
1963	read_lock(&neigh_tbl_lock);
1964	for (tbl = neigh_tables; tbl; tbl = tbl->next) {
 
 
 
1965		if (ndtmsg->ndtm_family && tbl->family != ndtmsg->ndtm_family)
1966			continue;
1967
1968		if (nla_strcmp(tb[NDTA_NAME], tbl->id) == 0)
1969			break;
 
1970	}
1971
1972	if (tbl == NULL) {
1973		err = -ENOENT;
1974		goto errout_locked;
1975	}
1976
1977	/*
1978	 * We acquire tbl->lock to be nice to the periodic timers and
1979	 * make sure they always see a consistent set of values.
1980	 */
1981	write_lock_bh(&tbl->lock);
1982
1983	if (tb[NDTA_PARMS]) {
1984		struct nlattr *tbp[NDTPA_MAX+1];
1985		struct neigh_parms *p;
1986		int i, ifindex = 0;
1987
1988		err = nla_parse_nested(tbp, NDTPA_MAX, tb[NDTA_PARMS],
1989				       nl_ntbl_parm_policy);
 
1990		if (err < 0)
1991			goto errout_tbl_lock;
1992
1993		if (tbp[NDTPA_IFINDEX])
1994			ifindex = nla_get_u32(tbp[NDTPA_IFINDEX]);
1995
1996		p = lookup_neigh_parms(tbl, net, ifindex);
1997		if (p == NULL) {
1998			err = -ENOENT;
1999			goto errout_tbl_lock;
2000		}
2001
2002		for (i = 1; i <= NDTPA_MAX; i++) {
2003			if (tbp[i] == NULL)
2004				continue;
2005
2006			switch (i) {
2007			case NDTPA_QUEUE_LEN:
2008				p->queue_len_bytes = nla_get_u32(tbp[i]) *
2009						     SKB_TRUESIZE(ETH_FRAME_LEN);
 
2010				break;
2011			case NDTPA_QUEUE_LENBYTES:
2012				p->queue_len_bytes = nla_get_u32(tbp[i]);
 
2013				break;
2014			case NDTPA_PROXY_QLEN:
2015				p->proxy_qlen = nla_get_u32(tbp[i]);
 
2016				break;
2017			case NDTPA_APP_PROBES:
2018				p->app_probes = nla_get_u32(tbp[i]);
 
2019				break;
2020			case NDTPA_UCAST_PROBES:
2021				p->ucast_probes = nla_get_u32(tbp[i]);
 
2022				break;
2023			case NDTPA_MCAST_PROBES:
2024				p->mcast_probes = nla_get_u32(tbp[i]);
 
 
 
 
 
2025				break;
2026			case NDTPA_BASE_REACHABLE_TIME:
2027				p->base_reachable_time = nla_get_msecs(tbp[i]);
 
 
 
 
 
 
 
2028				break;
2029			case NDTPA_GC_STALETIME:
2030				p->gc_staletime = nla_get_msecs(tbp[i]);
 
2031				break;
2032			case NDTPA_DELAY_PROBE_TIME:
2033				p->delay_probe_time = nla_get_msecs(tbp[i]);
 
 
2034				break;
2035			case NDTPA_RETRANS_TIME:
2036				p->retrans_time = nla_get_msecs(tbp[i]);
 
2037				break;
2038			case NDTPA_ANYCAST_DELAY:
2039				p->anycast_delay = nla_get_msecs(tbp[i]);
 
2040				break;
2041			case NDTPA_PROXY_DELAY:
2042				p->proxy_delay = nla_get_msecs(tbp[i]);
 
2043				break;
2044			case NDTPA_LOCKTIME:
2045				p->locktime = nla_get_msecs(tbp[i]);
 
2046				break;
2047			}
2048		}
2049	}
2050
 
 
 
 
 
 
2051	if (tb[NDTA_THRESH1])
2052		tbl->gc_thresh1 = nla_get_u32(tb[NDTA_THRESH1]);
2053
2054	if (tb[NDTA_THRESH2])
2055		tbl->gc_thresh2 = nla_get_u32(tb[NDTA_THRESH2]);
2056
2057	if (tb[NDTA_THRESH3])
2058		tbl->gc_thresh3 = nla_get_u32(tb[NDTA_THRESH3]);
2059
2060	if (tb[NDTA_GC_INTERVAL])
2061		tbl->gc_interval = nla_get_msecs(tb[NDTA_GC_INTERVAL]);
2062
2063	err = 0;
2064
2065errout_tbl_lock:
2066	write_unlock_bh(&tbl->lock);
2067errout_locked:
2068	read_unlock(&neigh_tbl_lock);
2069errout:
2070	return err;
2071}
2072
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2073static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2074{
 
2075	struct net *net = sock_net(skb->sk);
2076	int family, tidx, nidx = 0;
2077	int tbl_skip = cb->args[0];
2078	int neigh_skip = cb->args[1];
2079	struct neigh_table *tbl;
2080
2081	family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;
 
2082
2083	read_lock(&neigh_tbl_lock);
2084	for (tbl = neigh_tables, tidx = 0; tbl; tbl = tbl->next, tidx++) {
 
 
 
 
 
2085		struct neigh_parms *p;
2086
 
 
 
 
2087		if (tidx < tbl_skip || (family && tbl->family != family))
2088			continue;
2089
2090		if (neightbl_fill_info(skb, tbl, NETLINK_CB(cb->skb).pid,
2091				       cb->nlh->nlmsg_seq, RTM_NEWNEIGHTBL,
2092				       NLM_F_MULTI) <= 0)
2093			break;
2094
2095		for (nidx = 0, p = tbl->parms.next; p; p = p->next) {
 
 
2096			if (!net_eq(neigh_parms_net(p), net))
2097				continue;
2098
2099			if (nidx < neigh_skip)
2100				goto next;
2101
2102			if (neightbl_fill_param_info(skb, tbl, p,
2103						     NETLINK_CB(cb->skb).pid,
2104						     cb->nlh->nlmsg_seq,
2105						     RTM_NEWNEIGHTBL,
2106						     NLM_F_MULTI) <= 0)
2107				goto out;
2108		next:
2109			nidx++;
2110		}
2111
2112		neigh_skip = 0;
2113	}
2114out:
2115	read_unlock(&neigh_tbl_lock);
2116	cb->args[0] = tidx;
2117	cb->args[1] = nidx;
2118
2119	return skb->len;
2120}
2121
2122static int neigh_fill_info(struct sk_buff *skb, struct neighbour *neigh,
2123			   u32 pid, u32 seq, int type, unsigned int flags)
2124{
2125	unsigned long now = jiffies;
2126	struct nda_cacheinfo ci;
2127	struct nlmsghdr *nlh;
2128	struct ndmsg *ndm;
2129
2130	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
2131	if (nlh == NULL)
2132		return -EMSGSIZE;
2133
2134	ndm = nlmsg_data(nlh);
2135	ndm->ndm_family	 = neigh->ops->family;
2136	ndm->ndm_pad1    = 0;
2137	ndm->ndm_pad2    = 0;
2138	ndm->ndm_flags	 = neigh->flags;
2139	ndm->ndm_type	 = neigh->type;
2140	ndm->ndm_ifindex = neigh->dev->ifindex;
2141
2142	if (nla_put(skb, NDA_DST, neigh->tbl->key_len, neigh->primary_key))
2143		goto nla_put_failure;
2144
2145	read_lock_bh(&neigh->lock);
2146	ndm->ndm_state	 = neigh->nud_state;
2147	if (neigh->nud_state & NUD_VALID) {
2148		char haddr[MAX_ADDR_LEN];
2149
2150		neigh_ha_snapshot(haddr, neigh, neigh->dev);
2151		if (nla_put(skb, NDA_LLADDR, neigh->dev->addr_len, haddr) < 0) {
2152			read_unlock_bh(&neigh->lock);
2153			goto nla_put_failure;
2154		}
2155	}
2156
2157	ci.ndm_used	 = jiffies_to_clock_t(now - neigh->used);
2158	ci.ndm_confirmed = jiffies_to_clock_t(now - neigh->confirmed);
2159	ci.ndm_updated	 = jiffies_to_clock_t(now - neigh->updated);
2160	ci.ndm_refcnt	 = atomic_read(&neigh->refcnt) - 1;
2161	read_unlock_bh(&neigh->lock);
2162
2163	if (nla_put_u32(skb, NDA_PROBES, atomic_read(&neigh->probes)) ||
2164	    nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
2165		goto nla_put_failure;
2166
2167	return nlmsg_end(skb, nlh);
 
 
 
 
2168
2169nla_put_failure:
2170	nlmsg_cancel(skb, nlh);
2171	return -EMSGSIZE;
2172}
2173
2174static int pneigh_fill_info(struct sk_buff *skb, struct pneigh_entry *pn,
2175			    u32 pid, u32 seq, int type, unsigned int flags,
2176			    struct neigh_table *tbl)
2177{
2178	struct nlmsghdr *nlh;
2179	struct ndmsg *ndm;
2180
2181	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
2182	if (nlh == NULL)
2183		return -EMSGSIZE;
2184
2185	ndm = nlmsg_data(nlh);
2186	ndm->ndm_family	 = tbl->family;
2187	ndm->ndm_pad1    = 0;
2188	ndm->ndm_pad2    = 0;
2189	ndm->ndm_flags	 = pn->flags | NTF_PROXY;
2190	ndm->ndm_type	 = NDA_DST;
2191	ndm->ndm_ifindex = pn->dev->ifindex;
2192	ndm->ndm_state	 = NUD_NONE;
2193
2194	if (nla_put(skb, NDA_DST, tbl->key_len, pn->key))
2195		goto nla_put_failure;
2196
2197	return nlmsg_end(skb, nlh);
 
 
 
 
2198
2199nla_put_failure:
2200	nlmsg_cancel(skb, nlh);
2201	return -EMSGSIZE;
2202}
2203
2204static void neigh_update_notify(struct neighbour *neigh)
2205{
2206	call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
2207	__neigh_notify(neigh, RTM_NEWNEIGH, 0);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2208}
2209
 
 
 
 
 
2210static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
2211			    struct netlink_callback *cb)
 
2212{
2213	struct net *net = sock_net(skb->sk);
2214	struct neighbour *n;
2215	int rc, h, s_h = cb->args[1];
2216	int idx, s_idx = idx = cb->args[2];
2217	struct neigh_hash_table *nht;
 
 
 
 
2218
2219	rcu_read_lock_bh();
2220	nht = rcu_dereference_bh(tbl->nht);
2221
2222	for (h = s_h; h < (1 << nht->hash_shift); h++) {
2223		if (h > s_h)
2224			s_idx = 0;
2225		for (n = rcu_dereference_bh(nht->hash_buckets[h]), idx = 0;
2226		     n != NULL;
2227		     n = rcu_dereference_bh(n->next)) {
2228			if (!net_eq(dev_net(n->dev), net))
2229				continue;
2230			if (idx < s_idx)
 
2231				goto next;
2232			if (neigh_fill_info(skb, n, NETLINK_CB(cb->skb).pid,
2233					    cb->nlh->nlmsg_seq,
2234					    RTM_NEWNEIGH,
2235					    NLM_F_MULTI) <= 0) {
2236				rc = -1;
2237				goto out;
2238			}
2239next:
2240			idx++;
2241		}
2242	}
2243	rc = skb->len;
2244out:
2245	rcu_read_unlock_bh();
2246	cb->args[1] = h;
2247	cb->args[2] = idx;
2248	return rc;
2249}
2250
2251static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
2252			     struct netlink_callback *cb)
 
2253{
2254	struct pneigh_entry *n;
2255	struct net *net = sock_net(skb->sk);
2256	int rc, h, s_h = cb->args[3];
2257	int idx, s_idx = idx = cb->args[4];
 
 
 
 
2258
2259	read_lock_bh(&tbl->lock);
2260
2261	for (h = s_h; h <= PNEIGH_HASHMASK; h++) {
2262		if (h > s_h)
2263			s_idx = 0;
2264		for (n = tbl->phash_buckets[h], idx = 0; n; n = n->next) {
2265			if (dev_net(n->dev) != net)
2266				continue;
2267			if (idx < s_idx)
 
2268				goto next;
2269			if (pneigh_fill_info(skb, n, NETLINK_CB(cb->skb).pid,
2270					    cb->nlh->nlmsg_seq,
2271					    RTM_NEWNEIGH,
2272					    NLM_F_MULTI, tbl) <= 0) {
2273				read_unlock_bh(&tbl->lock);
2274				rc = -1;
2275				goto out;
2276			}
2277		next:
2278			idx++;
2279		}
2280	}
2281
2282	read_unlock_bh(&tbl->lock);
2283	rc = skb->len;
2284out:
2285	cb->args[3] = h;
2286	cb->args[4] = idx;
2287	return rc;
2288
2289}
2290
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2291static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
2292{
 
 
2293	struct neigh_table *tbl;
2294	int t, family, s_t;
2295	int proxy = 0;
2296	int err;
2297
2298	read_lock(&neigh_tbl_lock);
2299	family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;
2300
2301	/* check for full ndmsg structure presence, family member is
2302	 * the same for both structures
2303	 */
2304	if (nlmsg_len(cb->nlh) >= sizeof(struct ndmsg) &&
2305	    ((struct ndmsg *) nlmsg_data(cb->nlh))->ndm_flags == NTF_PROXY)
2306		proxy = 1;
2307
 
 
 
 
2308	s_t = cb->args[0];
2309
2310	for (tbl = neigh_tables, t = 0; tbl;
2311	     tbl = tbl->next, t++) {
 
 
 
2312		if (t < s_t || (family && tbl->family != family))
2313			continue;
2314		if (t > s_t)
2315			memset(&cb->args[1], 0, sizeof(cb->args) -
2316						sizeof(cb->args[0]));
2317		if (proxy)
2318			err = pneigh_dump_table(tbl, skb, cb);
2319		else
2320			err = neigh_dump_table(tbl, skb, cb);
2321		if (err < 0)
2322			break;
2323	}
2324	read_unlock(&neigh_tbl_lock);
2325
2326	cb->args[0] = t;
2327	return skb->len;
2328}
2329
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2330void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie)
2331{
2332	int chain;
2333	struct neigh_hash_table *nht;
2334
2335	rcu_read_lock_bh();
2336	nht = rcu_dereference_bh(tbl->nht);
2337
2338	read_lock(&tbl->lock); /* avoid resizes */
2339	for (chain = 0; chain < (1 << nht->hash_shift); chain++) {
2340		struct neighbour *n;
2341
2342		for (n = rcu_dereference_bh(nht->hash_buckets[chain]);
2343		     n != NULL;
2344		     n = rcu_dereference_bh(n->next))
2345			cb(n, cookie);
2346	}
2347	read_unlock(&tbl->lock);
2348	rcu_read_unlock_bh();
2349}
2350EXPORT_SYMBOL(neigh_for_each);
2351
2352/* The tbl->lock must be held as a writer and BH disabled. */
2353void __neigh_for_each_release(struct neigh_table *tbl,
2354			      int (*cb)(struct neighbour *))
2355{
2356	int chain;
2357	struct neigh_hash_table *nht;
2358
2359	nht = rcu_dereference_protected(tbl->nht,
2360					lockdep_is_held(&tbl->lock));
2361	for (chain = 0; chain < (1 << nht->hash_shift); chain++) {
2362		struct neighbour *n;
2363		struct neighbour __rcu **np;
2364
2365		np = &nht->hash_buckets[chain];
2366		while ((n = rcu_dereference_protected(*np,
2367					lockdep_is_held(&tbl->lock))) != NULL) {
2368			int release;
2369
2370			write_lock(&n->lock);
2371			release = cb(n);
2372			if (release) {
2373				rcu_assign_pointer(*np,
2374					rcu_dereference_protected(n->next,
2375						lockdep_is_held(&tbl->lock)));
2376				n->dead = 1;
2377			} else
2378				np = &n->next;
2379			write_unlock(&n->lock);
2380			if (release)
2381				neigh_cleanup_and_release(n);
2382		}
2383	}
2384}
2385EXPORT_SYMBOL(__neigh_for_each_release);
2386
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2387#ifdef CONFIG_PROC_FS
2388
2389static struct neighbour *neigh_get_first(struct seq_file *seq)
2390{
2391	struct neigh_seq_state *state = seq->private;
2392	struct net *net = seq_file_net(seq);
2393	struct neigh_hash_table *nht = state->nht;
2394	struct neighbour *n = NULL;
2395	int bucket = state->bucket;
2396
2397	state->flags &= ~NEIGH_SEQ_IS_PNEIGH;
2398	for (bucket = 0; bucket < (1 << nht->hash_shift); bucket++) {
2399		n = rcu_dereference_bh(nht->hash_buckets[bucket]);
2400
2401		while (n) {
2402			if (!net_eq(dev_net(n->dev), net))
2403				goto next;
2404			if (state->neigh_sub_iter) {
2405				loff_t fakep = 0;
2406				void *v;
2407
2408				v = state->neigh_sub_iter(state, n, &fakep);
2409				if (!v)
2410					goto next;
2411			}
2412			if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
2413				break;
2414			if (n->nud_state & ~NUD_NOARP)
2415				break;
2416next:
2417			n = rcu_dereference_bh(n->next);
2418		}
2419
2420		if (n)
2421			break;
2422	}
2423	state->bucket = bucket;
2424
2425	return n;
2426}
2427
2428static struct neighbour *neigh_get_next(struct seq_file *seq,
2429					struct neighbour *n,
2430					loff_t *pos)
2431{
2432	struct neigh_seq_state *state = seq->private;
2433	struct net *net = seq_file_net(seq);
2434	struct neigh_hash_table *nht = state->nht;
2435
2436	if (state->neigh_sub_iter) {
2437		void *v = state->neigh_sub_iter(state, n, pos);
2438		if (v)
2439			return n;
2440	}
2441	n = rcu_dereference_bh(n->next);
2442
2443	while (1) {
2444		while (n) {
2445			if (!net_eq(dev_net(n->dev), net))
2446				goto next;
2447			if (state->neigh_sub_iter) {
2448				void *v = state->neigh_sub_iter(state, n, pos);
2449				if (v)
2450					return n;
2451				goto next;
2452			}
2453			if (!(state->flags & NEIGH_SEQ_SKIP_NOARP))
2454				break;
2455
2456			if (n->nud_state & ~NUD_NOARP)
2457				break;
2458next:
2459			n = rcu_dereference_bh(n->next);
2460		}
2461
2462		if (n)
2463			break;
2464
2465		if (++state->bucket >= (1 << nht->hash_shift))
2466			break;
2467
2468		n = rcu_dereference_bh(nht->hash_buckets[state->bucket]);
2469	}
2470
2471	if (n && pos)
2472		--(*pos);
2473	return n;
2474}
2475
2476static struct neighbour *neigh_get_idx(struct seq_file *seq, loff_t *pos)
2477{
2478	struct neighbour *n = neigh_get_first(seq);
2479
2480	if (n) {
2481		--(*pos);
2482		while (*pos) {
2483			n = neigh_get_next(seq, n, pos);
2484			if (!n)
2485				break;
2486		}
2487	}
2488	return *pos ? NULL : n;
2489}
2490
2491static struct pneigh_entry *pneigh_get_first(struct seq_file *seq)
2492{
2493	struct neigh_seq_state *state = seq->private;
2494	struct net *net = seq_file_net(seq);
2495	struct neigh_table *tbl = state->tbl;
2496	struct pneigh_entry *pn = NULL;
2497	int bucket = state->bucket;
2498
2499	state->flags |= NEIGH_SEQ_IS_PNEIGH;
2500	for (bucket = 0; bucket <= PNEIGH_HASHMASK; bucket++) {
2501		pn = tbl->phash_buckets[bucket];
2502		while (pn && !net_eq(pneigh_net(pn), net))
2503			pn = pn->next;
2504		if (pn)
2505			break;
2506	}
2507	state->bucket = bucket;
2508
2509	return pn;
2510}
2511
2512static struct pneigh_entry *pneigh_get_next(struct seq_file *seq,
2513					    struct pneigh_entry *pn,
2514					    loff_t *pos)
2515{
2516	struct neigh_seq_state *state = seq->private;
2517	struct net *net = seq_file_net(seq);
2518	struct neigh_table *tbl = state->tbl;
2519
2520	do {
2521		pn = pn->next;
2522	} while (pn && !net_eq(pneigh_net(pn), net));
2523
2524	while (!pn) {
2525		if (++state->bucket > PNEIGH_HASHMASK)
2526			break;
2527		pn = tbl->phash_buckets[state->bucket];
2528		while (pn && !net_eq(pneigh_net(pn), net))
2529			pn = pn->next;
2530		if (pn)
2531			break;
2532	}
2533
2534	if (pn && pos)
2535		--(*pos);
2536
2537	return pn;
2538}
2539
2540static struct pneigh_entry *pneigh_get_idx(struct seq_file *seq, loff_t *pos)
2541{
2542	struct pneigh_entry *pn = pneigh_get_first(seq);
2543
2544	if (pn) {
2545		--(*pos);
2546		while (*pos) {
2547			pn = pneigh_get_next(seq, pn, pos);
2548			if (!pn)
2549				break;
2550		}
2551	}
2552	return *pos ? NULL : pn;
2553}
2554
2555static void *neigh_get_idx_any(struct seq_file *seq, loff_t *pos)
2556{
2557	struct neigh_seq_state *state = seq->private;
2558	void *rc;
2559	loff_t idxpos = *pos;
2560
2561	rc = neigh_get_idx(seq, &idxpos);
2562	if (!rc && !(state->flags & NEIGH_SEQ_NEIGH_ONLY))
2563		rc = pneigh_get_idx(seq, &idxpos);
2564
2565	return rc;
2566}
2567
2568void *neigh_seq_start(struct seq_file *seq, loff_t *pos, struct neigh_table *tbl, unsigned int neigh_seq_flags)
 
2569	__acquires(rcu_bh)
2570{
2571	struct neigh_seq_state *state = seq->private;
2572
2573	state->tbl = tbl;
2574	state->bucket = 0;
2575	state->flags = (neigh_seq_flags & ~NEIGH_SEQ_IS_PNEIGH);
2576
2577	rcu_read_lock_bh();
2578	state->nht = rcu_dereference_bh(tbl->nht);
 
2579
2580	return *pos ? neigh_get_idx_any(seq, pos) : SEQ_START_TOKEN;
2581}
2582EXPORT_SYMBOL(neigh_seq_start);
2583
2584void *neigh_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2585{
2586	struct neigh_seq_state *state;
2587	void *rc;
2588
2589	if (v == SEQ_START_TOKEN) {
2590		rc = neigh_get_first(seq);
2591		goto out;
2592	}
2593
2594	state = seq->private;
2595	if (!(state->flags & NEIGH_SEQ_IS_PNEIGH)) {
2596		rc = neigh_get_next(seq, v, NULL);
2597		if (rc)
2598			goto out;
2599		if (!(state->flags & NEIGH_SEQ_NEIGH_ONLY))
2600			rc = pneigh_get_first(seq);
2601	} else {
2602		BUG_ON(state->flags & NEIGH_SEQ_NEIGH_ONLY);
2603		rc = pneigh_get_next(seq, v, NULL);
2604	}
2605out:
2606	++(*pos);
2607	return rc;
2608}
2609EXPORT_SYMBOL(neigh_seq_next);
2610
2611void neigh_seq_stop(struct seq_file *seq, void *v)
 
2612	__releases(rcu_bh)
2613{
 
 
 
 
2614	rcu_read_unlock_bh();
2615}
2616EXPORT_SYMBOL(neigh_seq_stop);
2617
2618/* statistics via seq_file */
2619
2620static void *neigh_stat_seq_start(struct seq_file *seq, loff_t *pos)
2621{
2622	struct neigh_table *tbl = seq->private;
2623	int cpu;
2624
2625	if (*pos == 0)
2626		return SEQ_START_TOKEN;
2627
2628	for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
2629		if (!cpu_possible(cpu))
2630			continue;
2631		*pos = cpu+1;
2632		return per_cpu_ptr(tbl->stats, cpu);
2633	}
2634	return NULL;
2635}
2636
2637static void *neigh_stat_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2638{
2639	struct neigh_table *tbl = seq->private;
2640	int cpu;
2641
2642	for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
2643		if (!cpu_possible(cpu))
2644			continue;
2645		*pos = cpu+1;
2646		return per_cpu_ptr(tbl->stats, cpu);
2647	}
 
2648	return NULL;
2649}
2650
2651static void neigh_stat_seq_stop(struct seq_file *seq, void *v)
2652{
2653
2654}
2655
2656static int neigh_stat_seq_show(struct seq_file *seq, void *v)
2657{
2658	struct neigh_table *tbl = seq->private;
2659	struct neigh_statistics *st = v;
2660
2661	if (v == SEQ_START_TOKEN) {
2662		seq_printf(seq, "entries  allocs destroys hash_grows  lookups hits  res_failed  rcv_probes_mcast rcv_probes_ucast  periodic_gc_runs forced_gc_runs unresolved_discards\n");
2663		return 0;
2664	}
2665
2666	seq_printf(seq, "%08x  %08lx %08lx %08lx  %08lx %08lx  %08lx  "
2667			"%08lx %08lx  %08lx %08lx %08lx\n",
2668		   atomic_read(&tbl->entries),
2669
2670		   st->allocs,
2671		   st->destroys,
2672		   st->hash_grows,
2673
2674		   st->lookups,
2675		   st->hits,
2676
2677		   st->res_failed,
2678
2679		   st->rcv_probes_mcast,
2680		   st->rcv_probes_ucast,
2681
2682		   st->periodic_gc_runs,
2683		   st->forced_gc_runs,
2684		   st->unres_discards
 
2685		   );
2686
2687	return 0;
2688}
2689
2690static const struct seq_operations neigh_stat_seq_ops = {
2691	.start	= neigh_stat_seq_start,
2692	.next	= neigh_stat_seq_next,
2693	.stop	= neigh_stat_seq_stop,
2694	.show	= neigh_stat_seq_show,
2695};
2696
2697static int neigh_stat_seq_open(struct inode *inode, struct file *file)
2698{
2699	int ret = seq_open(file, &neigh_stat_seq_ops);
2700
2701	if (!ret) {
2702		struct seq_file *sf = file->private_data;
2703		sf->private = PDE(inode)->data;
2704	}
2705	return ret;
2706};
2707
2708static const struct file_operations neigh_stat_seq_fops = {
2709	.owner	 = THIS_MODULE,
2710	.open 	 = neigh_stat_seq_open,
2711	.read	 = seq_read,
2712	.llseek	 = seq_lseek,
2713	.release = seq_release,
2714};
2715
2716#endif /* CONFIG_PROC_FS */
2717
2718static inline size_t neigh_nlmsg_size(void)
2719{
2720	return NLMSG_ALIGN(sizeof(struct ndmsg))
2721	       + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
2722	       + nla_total_size(MAX_ADDR_LEN) /* NDA_LLADDR */
2723	       + nla_total_size(sizeof(struct nda_cacheinfo))
2724	       + nla_total_size(4); /* NDA_PROBES */
2725}
2726
2727static void __neigh_notify(struct neighbour *n, int type, int flags)
2728{
2729	struct net *net = dev_net(n->dev);
2730	struct sk_buff *skb;
2731	int err = -ENOBUFS;
2732
2733	skb = nlmsg_new(neigh_nlmsg_size(), GFP_ATOMIC);
2734	if (skb == NULL)
2735		goto errout;
2736
2737	err = neigh_fill_info(skb, n, 0, 0, type, flags);
2738	if (err < 0) {
2739		/* -EMSGSIZE implies BUG in neigh_nlmsg_size() */
2740		WARN_ON(err == -EMSGSIZE);
2741		kfree_skb(skb);
2742		goto errout;
2743	}
2744	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
2745	return;
2746errout:
2747	if (err < 0)
2748		rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
2749}
2750
2751#ifdef CONFIG_ARPD
2752void neigh_app_ns(struct neighbour *n)
2753{
2754	__neigh_notify(n, RTM_GETNEIGH, NLM_F_REQUEST);
2755}
2756EXPORT_SYMBOL(neigh_app_ns);
2757#endif /* CONFIG_ARPD */
2758
2759#ifdef CONFIG_SYSCTL
 
2760
2761static int proc_unres_qlen(ctl_table *ctl, int write, void __user *buffer,
2762			   size_t *lenp, loff_t *ppos)
2763{
2764	int size, ret;
2765	ctl_table tmp = *ctl;
2766
 
 
2767	tmp.data = &size;
2768	size = DIV_ROUND_UP(*(int *)ctl->data, SKB_TRUESIZE(ETH_FRAME_LEN));
2769	ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
 
 
2770	if (write && !ret)
2771		*(int *)ctl->data = size * SKB_TRUESIZE(ETH_FRAME_LEN);
2772	return ret;
2773}
2774
2775enum {
2776	NEIGH_VAR_MCAST_PROBE,
2777	NEIGH_VAR_UCAST_PROBE,
2778	NEIGH_VAR_APP_PROBE,
2779	NEIGH_VAR_RETRANS_TIME,
2780	NEIGH_VAR_BASE_REACHABLE_TIME,
2781	NEIGH_VAR_DELAY_PROBE_TIME,
2782	NEIGH_VAR_GC_STALETIME,
2783	NEIGH_VAR_QUEUE_LEN,
2784	NEIGH_VAR_QUEUE_LEN_BYTES,
2785	NEIGH_VAR_PROXY_QLEN,
2786	NEIGH_VAR_ANYCAST_DELAY,
2787	NEIGH_VAR_PROXY_DELAY,
2788	NEIGH_VAR_LOCKTIME,
2789	NEIGH_VAR_RETRANS_TIME_MS,
2790	NEIGH_VAR_BASE_REACHABLE_TIME_MS,
2791	NEIGH_VAR_GC_INTERVAL,
2792	NEIGH_VAR_GC_THRESH1,
2793	NEIGH_VAR_GC_THRESH2,
2794	NEIGH_VAR_GC_THRESH3,
2795	NEIGH_VAR_MAX
2796};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2797
2798static struct neigh_sysctl_table {
2799	struct ctl_table_header *sysctl_header;
2800	struct ctl_table neigh_vars[NEIGH_VAR_MAX + 1];
2801} neigh_sysctl_template __read_mostly = {
2802	.neigh_vars = {
2803		[NEIGH_VAR_MCAST_PROBE] = {
2804			.procname	= "mcast_solicit",
2805			.maxlen		= sizeof(int),
2806			.mode		= 0644,
2807			.proc_handler	= proc_dointvec,
2808		},
2809		[NEIGH_VAR_UCAST_PROBE] = {
2810			.procname	= "ucast_solicit",
2811			.maxlen		= sizeof(int),
2812			.mode		= 0644,
2813			.proc_handler	= proc_dointvec,
2814		},
2815		[NEIGH_VAR_APP_PROBE] = {
2816			.procname	= "app_solicit",
2817			.maxlen		= sizeof(int),
2818			.mode		= 0644,
2819			.proc_handler	= proc_dointvec,
2820		},
2821		[NEIGH_VAR_RETRANS_TIME] = {
2822			.procname	= "retrans_time",
2823			.maxlen		= sizeof(int),
2824			.mode		= 0644,
2825			.proc_handler	= proc_dointvec_userhz_jiffies,
2826		},
2827		[NEIGH_VAR_BASE_REACHABLE_TIME] = {
2828			.procname	= "base_reachable_time",
2829			.maxlen		= sizeof(int),
2830			.mode		= 0644,
2831			.proc_handler	= proc_dointvec_jiffies,
2832		},
2833		[NEIGH_VAR_DELAY_PROBE_TIME] = {
2834			.procname	= "delay_first_probe_time",
2835			.maxlen		= sizeof(int),
2836			.mode		= 0644,
2837			.proc_handler	= proc_dointvec_jiffies,
2838		},
2839		[NEIGH_VAR_GC_STALETIME] = {
2840			.procname	= "gc_stale_time",
2841			.maxlen		= sizeof(int),
2842			.mode		= 0644,
2843			.proc_handler	= proc_dointvec_jiffies,
2844		},
2845		[NEIGH_VAR_QUEUE_LEN] = {
2846			.procname	= "unres_qlen",
2847			.maxlen		= sizeof(int),
2848			.mode		= 0644,
2849			.proc_handler	= proc_unres_qlen,
2850		},
2851		[NEIGH_VAR_QUEUE_LEN_BYTES] = {
2852			.procname	= "unres_qlen_bytes",
2853			.maxlen		= sizeof(int),
2854			.mode		= 0644,
2855			.proc_handler	= proc_dointvec,
2856		},
2857		[NEIGH_VAR_PROXY_QLEN] = {
2858			.procname	= "proxy_qlen",
2859			.maxlen		= sizeof(int),
2860			.mode		= 0644,
2861			.proc_handler	= proc_dointvec,
2862		},
2863		[NEIGH_VAR_ANYCAST_DELAY] = {
2864			.procname	= "anycast_delay",
2865			.maxlen		= sizeof(int),
2866			.mode		= 0644,
2867			.proc_handler	= proc_dointvec_userhz_jiffies,
2868		},
2869		[NEIGH_VAR_PROXY_DELAY] = {
2870			.procname	= "proxy_delay",
2871			.maxlen		= sizeof(int),
2872			.mode		= 0644,
2873			.proc_handler	= proc_dointvec_userhz_jiffies,
2874		},
2875		[NEIGH_VAR_LOCKTIME] = {
2876			.procname	= "locktime",
2877			.maxlen		= sizeof(int),
2878			.mode		= 0644,
2879			.proc_handler	= proc_dointvec_userhz_jiffies,
2880		},
2881		[NEIGH_VAR_RETRANS_TIME_MS] = {
2882			.procname	= "retrans_time_ms",
2883			.maxlen		= sizeof(int),
2884			.mode		= 0644,
2885			.proc_handler	= proc_dointvec_ms_jiffies,
2886		},
2887		[NEIGH_VAR_BASE_REACHABLE_TIME_MS] = {
2888			.procname	= "base_reachable_time_ms",
2889			.maxlen		= sizeof(int),
2890			.mode		= 0644,
2891			.proc_handler	= proc_dointvec_ms_jiffies,
2892		},
2893		[NEIGH_VAR_GC_INTERVAL] = {
2894			.procname	= "gc_interval",
2895			.maxlen		= sizeof(int),
2896			.mode		= 0644,
2897			.proc_handler	= proc_dointvec_jiffies,
2898		},
2899		[NEIGH_VAR_GC_THRESH1] = {
2900			.procname	= "gc_thresh1",
2901			.maxlen		= sizeof(int),
2902			.mode		= 0644,
2903			.proc_handler	= proc_dointvec,
 
 
2904		},
2905		[NEIGH_VAR_GC_THRESH2] = {
2906			.procname	= "gc_thresh2",
2907			.maxlen		= sizeof(int),
2908			.mode		= 0644,
2909			.proc_handler	= proc_dointvec,
 
 
2910		},
2911		[NEIGH_VAR_GC_THRESH3] = {
2912			.procname	= "gc_thresh3",
2913			.maxlen		= sizeof(int),
2914			.mode		= 0644,
2915			.proc_handler	= proc_dointvec,
 
 
2916		},
2917		{},
2918	},
2919};
2920
2921int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
2922			  char *p_name, proc_handler *handler)
2923{
 
2924	struct neigh_sysctl_table *t;
2925	const char *dev_name_source = NULL;
2926	char neigh_path[ sizeof("net//neigh/") + IFNAMSIZ + IFNAMSIZ ];
 
2927
2928	t = kmemdup(&neigh_sysctl_template, sizeof(*t), GFP_KERNEL);
2929	if (!t)
2930		goto err;
2931
2932	t->neigh_vars[NEIGH_VAR_MCAST_PROBE].data  = &p->mcast_probes;
2933	t->neigh_vars[NEIGH_VAR_UCAST_PROBE].data  = &p->ucast_probes;
2934	t->neigh_vars[NEIGH_VAR_APP_PROBE].data  = &p->app_probes;
2935	t->neigh_vars[NEIGH_VAR_RETRANS_TIME].data  = &p->retrans_time;
2936	t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].data  = &p->base_reachable_time;
2937	t->neigh_vars[NEIGH_VAR_DELAY_PROBE_TIME].data  = &p->delay_probe_time;
2938	t->neigh_vars[NEIGH_VAR_GC_STALETIME].data  = &p->gc_staletime;
2939	t->neigh_vars[NEIGH_VAR_QUEUE_LEN].data  = &p->queue_len_bytes;
2940	t->neigh_vars[NEIGH_VAR_QUEUE_LEN_BYTES].data  = &p->queue_len_bytes;
2941	t->neigh_vars[NEIGH_VAR_PROXY_QLEN].data  = &p->proxy_qlen;
2942	t->neigh_vars[NEIGH_VAR_ANYCAST_DELAY].data  = &p->anycast_delay;
2943	t->neigh_vars[NEIGH_VAR_PROXY_DELAY].data = &p->proxy_delay;
2944	t->neigh_vars[NEIGH_VAR_LOCKTIME].data = &p->locktime;
2945	t->neigh_vars[NEIGH_VAR_RETRANS_TIME_MS].data  = &p->retrans_time;
2946	t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].data  = &p->base_reachable_time;
2947
2948	if (dev) {
2949		dev_name_source = dev->name;
2950		/* Terminate the table early */
2951		memset(&t->neigh_vars[NEIGH_VAR_GC_INTERVAL], 0,
2952		       sizeof(t->neigh_vars[NEIGH_VAR_GC_INTERVAL]));
2953	} else {
 
2954		dev_name_source = "default";
2955		t->neigh_vars[NEIGH_VAR_GC_INTERVAL].data = (int *)(p + 1);
2956		t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = (int *)(p + 1) + 1;
2957		t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = (int *)(p + 1) + 2;
2958		t->neigh_vars[NEIGH_VAR_GC_THRESH3].data = (int *)(p + 1) + 3;
2959	}
2960
2961
2962	if (handler) {
2963		/* RetransTime */
2964		t->neigh_vars[NEIGH_VAR_RETRANS_TIME].proc_handler = handler;
2965		t->neigh_vars[NEIGH_VAR_RETRANS_TIME].extra1 = dev;
2966		/* ReachableTime */
2967		t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].proc_handler = handler;
2968		t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME].extra1 = dev;
2969		/* RetransTime (in milliseconds)*/
2970		t->neigh_vars[NEIGH_VAR_RETRANS_TIME_MS].proc_handler = handler;
2971		t->neigh_vars[NEIGH_VAR_RETRANS_TIME_MS].extra1 = dev;
2972		/* ReachableTime (in milliseconds) */
2973		t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].proc_handler = handler;
2974		t->neigh_vars[NEIGH_VAR_BASE_REACHABLE_TIME_MS].extra1 = dev;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2975	}
2976
2977	snprintf(neigh_path, sizeof(neigh_path), "net/%s/neigh/%s",
2978		p_name, dev_name_source);
2979	t->sysctl_header =
2980		register_net_sysctl(neigh_parms_net(p), neigh_path, t->neigh_vars);
2981	if (!t->sysctl_header)
2982		goto free;
2983
2984	p->sysctl_table = t;
2985	return 0;
2986
2987free:
2988	kfree(t);
2989err:
2990	return -ENOBUFS;
2991}
2992EXPORT_SYMBOL(neigh_sysctl_register);
2993
2994void neigh_sysctl_unregister(struct neigh_parms *p)
2995{
2996	if (p->sysctl_table) {
2997		struct neigh_sysctl_table *t = p->sysctl_table;
2998		p->sysctl_table = NULL;
2999		unregister_net_sysctl_table(t->sysctl_header);
3000		kfree(t);
3001	}
3002}
3003EXPORT_SYMBOL(neigh_sysctl_unregister);
3004
3005#endif	/* CONFIG_SYSCTL */
3006
3007static int __init neigh_init(void)
3008{
3009	rtnl_register(PF_UNSPEC, RTM_NEWNEIGH, neigh_add, NULL, NULL);
3010	rtnl_register(PF_UNSPEC, RTM_DELNEIGH, neigh_delete, NULL, NULL);
3011	rtnl_register(PF_UNSPEC, RTM_GETNEIGH, NULL, neigh_dump_info, NULL);
3012
3013	rtnl_register(PF_UNSPEC, RTM_GETNEIGHTBL, NULL, neightbl_dump_info,
3014		      NULL);
3015	rtnl_register(PF_UNSPEC, RTM_SETNEIGHTBL, neightbl_set, NULL, NULL);
3016
3017	return 0;
3018}
3019
3020subsys_initcall(neigh_init);
3021