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/net/bridge/br_fdb.c

http://github.com/mirrors/linux
C | 1208 lines | 931 code | 185 blank | 92 comment | 205 complexity | e2b9bb89280007da717b26da203f40ed MD5 | raw file
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *	Forwarding database
   4 *	Linux ethernet bridge
   5 *
   6 *	Authors:
   7 *	Lennert Buytenhek		<buytenh@gnu.org>
   8 */
   9
  10#include <linux/kernel.h>
  11#include <linux/init.h>
  12#include <linux/rculist.h>
  13#include <linux/spinlock.h>
  14#include <linux/times.h>
  15#include <linux/netdevice.h>
  16#include <linux/etherdevice.h>
  17#include <linux/jhash.h>
  18#include <linux/random.h>
  19#include <linux/slab.h>
  20#include <linux/atomic.h>
  21#include <asm/unaligned.h>
  22#include <linux/if_vlan.h>
  23#include <net/switchdev.h>
  24#include <trace/events/bridge.h>
  25#include "br_private.h"
  26
  27static const struct rhashtable_params br_fdb_rht_params = {
  28	.head_offset = offsetof(struct net_bridge_fdb_entry, rhnode),
  29	.key_offset = offsetof(struct net_bridge_fdb_entry, key),
  30	.key_len = sizeof(struct net_bridge_fdb_key),
  31	.automatic_shrinking = true,
  32};
  33
  34static struct kmem_cache *br_fdb_cache __read_mostly;
  35static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  36		      const unsigned char *addr, u16 vid);
  37static void fdb_notify(struct net_bridge *br,
  38		       const struct net_bridge_fdb_entry *, int, bool);
  39
  40int __init br_fdb_init(void)
  41{
  42	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  43					 sizeof(struct net_bridge_fdb_entry),
  44					 0,
  45					 SLAB_HWCACHE_ALIGN, NULL);
  46	if (!br_fdb_cache)
  47		return -ENOMEM;
  48
  49	return 0;
  50}
  51
  52void br_fdb_fini(void)
  53{
  54	kmem_cache_destroy(br_fdb_cache);
  55}
  56
  57int br_fdb_hash_init(struct net_bridge *br)
  58{
  59	return rhashtable_init(&br->fdb_hash_tbl, &br_fdb_rht_params);
  60}
  61
  62void br_fdb_hash_fini(struct net_bridge *br)
  63{
  64	rhashtable_destroy(&br->fdb_hash_tbl);
  65}
  66
  67/* if topology_changing then use forward_delay (default 15 sec)
  68 * otherwise keep longer (default 5 minutes)
  69 */
  70static inline unsigned long hold_time(const struct net_bridge *br)
  71{
  72	return br->topology_change ? br->forward_delay : br->ageing_time;
  73}
  74
  75static inline int has_expired(const struct net_bridge *br,
  76				  const struct net_bridge_fdb_entry *fdb)
  77{
  78	return !test_bit(BR_FDB_STATIC, &fdb->flags) &&
  79	       !test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags) &&
  80	       time_before_eq(fdb->updated + hold_time(br), jiffies);
  81}
  82
  83static void fdb_rcu_free(struct rcu_head *head)
  84{
  85	struct net_bridge_fdb_entry *ent
  86		= container_of(head, struct net_bridge_fdb_entry, rcu);
  87	kmem_cache_free(br_fdb_cache, ent);
  88}
  89
  90static struct net_bridge_fdb_entry *fdb_find_rcu(struct rhashtable *tbl,
  91						 const unsigned char *addr,
  92						 __u16 vid)
  93{
  94	struct net_bridge_fdb_key key;
  95
  96	WARN_ON_ONCE(!rcu_read_lock_held());
  97
  98	key.vlan_id = vid;
  99	memcpy(key.addr.addr, addr, sizeof(key.addr.addr));
 100
 101	return rhashtable_lookup(tbl, &key, br_fdb_rht_params);
 102}
 103
 104/* requires bridge hash_lock */
 105static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
 106						const unsigned char *addr,
 107						__u16 vid)
 108{
 109	struct net_bridge_fdb_entry *fdb;
 110
 111	lockdep_assert_held_once(&br->hash_lock);
 112
 113	rcu_read_lock();
 114	fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 115	rcu_read_unlock();
 116
 117	return fdb;
 118}
 119
 120struct net_device *br_fdb_find_port(const struct net_device *br_dev,
 121				    const unsigned char *addr,
 122				    __u16 vid)
 123{
 124	struct net_bridge_fdb_entry *f;
 125	struct net_device *dev = NULL;
 126	struct net_bridge *br;
 127
 128	ASSERT_RTNL();
 129
 130	if (!netif_is_bridge_master(br_dev))
 131		return NULL;
 132
 133	br = netdev_priv(br_dev);
 134	rcu_read_lock();
 135	f = br_fdb_find_rcu(br, addr, vid);
 136	if (f && f->dst)
 137		dev = f->dst->dev;
 138	rcu_read_unlock();
 139
 140	return dev;
 141}
 142EXPORT_SYMBOL_GPL(br_fdb_find_port);
 143
 144struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
 145					     const unsigned char *addr,
 146					     __u16 vid)
 147{
 148	return fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 149}
 150
 151/* When a static FDB entry is added, the mac address from the entry is
 152 * added to the bridge private HW address list and all required ports
 153 * are then updated with the new information.
 154 * Called under RTNL.
 155 */
 156static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
 157{
 158	int err;
 159	struct net_bridge_port *p;
 160
 161	ASSERT_RTNL();
 162
 163	list_for_each_entry(p, &br->port_list, list) {
 164		if (!br_promisc_port(p)) {
 165			err = dev_uc_add(p->dev, addr);
 166			if (err)
 167				goto undo;
 168		}
 169	}
 170
 171	return;
 172undo:
 173	list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 174		if (!br_promisc_port(p))
 175			dev_uc_del(p->dev, addr);
 176	}
 177}
 178
 179/* When a static FDB entry is deleted, the HW address from that entry is
 180 * also removed from the bridge private HW address list and updates all
 181 * the ports with needed information.
 182 * Called under RTNL.
 183 */
 184static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 185{
 186	struct net_bridge_port *p;
 187
 188	ASSERT_RTNL();
 189
 190	list_for_each_entry(p, &br->port_list, list) {
 191		if (!br_promisc_port(p))
 192			dev_uc_del(p->dev, addr);
 193	}
 194}
 195
 196static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f,
 197		       bool swdev_notify)
 198{
 199	trace_fdb_delete(br, f);
 200
 201	if (test_bit(BR_FDB_STATIC, &f->flags))
 202		fdb_del_hw_addr(br, f->key.addr.addr);
 203
 204	hlist_del_init_rcu(&f->fdb_node);
 205	rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode,
 206			       br_fdb_rht_params);
 207	fdb_notify(br, f, RTM_DELNEIGH, swdev_notify);
 208	call_rcu(&f->rcu, fdb_rcu_free);
 209}
 210
 211/* Delete a local entry if no other port had the same address. */
 212static void fdb_delete_local(struct net_bridge *br,
 213			     const struct net_bridge_port *p,
 214			     struct net_bridge_fdb_entry *f)
 215{
 216	const unsigned char *addr = f->key.addr.addr;
 217	struct net_bridge_vlan_group *vg;
 218	const struct net_bridge_vlan *v;
 219	struct net_bridge_port *op;
 220	u16 vid = f->key.vlan_id;
 221
 222	/* Maybe another port has same hw addr? */
 223	list_for_each_entry(op, &br->port_list, list) {
 224		vg = nbp_vlan_group(op);
 225		if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 226		    (!vid || br_vlan_find(vg, vid))) {
 227			f->dst = op;
 228			clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
 229			return;
 230		}
 231	}
 232
 233	vg = br_vlan_group(br);
 234	v = br_vlan_find(vg, vid);
 235	/* Maybe bridge device has same hw addr? */
 236	if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 237	    (!vid || (v && br_vlan_should_use(v)))) {
 238		f->dst = NULL;
 239		clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
 240		return;
 241	}
 242
 243	fdb_delete(br, f, true);
 244}
 245
 246void br_fdb_find_delete_local(struct net_bridge *br,
 247			      const struct net_bridge_port *p,
 248			      const unsigned char *addr, u16 vid)
 249{
 250	struct net_bridge_fdb_entry *f;
 251
 252	spin_lock_bh(&br->hash_lock);
 253	f = br_fdb_find(br, addr, vid);
 254	if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
 255	    !test_bit(BR_FDB_ADDED_BY_USER, &f->flags) && f->dst == p)
 256		fdb_delete_local(br, p, f);
 257	spin_unlock_bh(&br->hash_lock);
 258}
 259
 260void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 261{
 262	struct net_bridge_vlan_group *vg;
 263	struct net_bridge_fdb_entry *f;
 264	struct net_bridge *br = p->br;
 265	struct net_bridge_vlan *v;
 266
 267	spin_lock_bh(&br->hash_lock);
 268	vg = nbp_vlan_group(p);
 269	hlist_for_each_entry(f, &br->fdb_list, fdb_node) {
 270		if (f->dst == p && test_bit(BR_FDB_LOCAL, &f->flags) &&
 271		    !test_bit(BR_FDB_ADDED_BY_USER, &f->flags)) {
 272			/* delete old one */
 273			fdb_delete_local(br, p, f);
 274
 275			/* if this port has no vlan information
 276			 * configured, we can safely be done at
 277			 * this point.
 278			 */
 279			if (!vg || !vg->num_vlans)
 280				goto insert;
 281		}
 282	}
 283
 284insert:
 285	/* insert new address,  may fail if invalid address or dup. */
 286	fdb_insert(br, p, newaddr, 0);
 287
 288	if (!vg || !vg->num_vlans)
 289		goto done;
 290
 291	/* Now add entries for every VLAN configured on the port.
 292	 * This function runs under RTNL so the bitmap will not change
 293	 * from under us.
 294	 */
 295	list_for_each_entry(v, &vg->vlan_list, vlist)
 296		fdb_insert(br, p, newaddr, v->vid);
 297
 298done:
 299	spin_unlock_bh(&br->hash_lock);
 300}
 301
 302void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 303{
 304	struct net_bridge_vlan_group *vg;
 305	struct net_bridge_fdb_entry *f;
 306	struct net_bridge_vlan *v;
 307
 308	spin_lock_bh(&br->hash_lock);
 309
 310	/* If old entry was unassociated with any port, then delete it. */
 311	f = br_fdb_find(br, br->dev->dev_addr, 0);
 312	if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
 313	    !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags))
 314		fdb_delete_local(br, NULL, f);
 315
 316	fdb_insert(br, NULL, newaddr, 0);
 317	vg = br_vlan_group(br);
 318	if (!vg || !vg->num_vlans)
 319		goto out;
 320	/* Now remove and add entries for every VLAN configured on the
 321	 * bridge.  This function runs under RTNL so the bitmap will not
 322	 * change from under us.
 323	 */
 324	list_for_each_entry(v, &vg->vlan_list, vlist) {
 325		if (!br_vlan_should_use(v))
 326			continue;
 327		f = br_fdb_find(br, br->dev->dev_addr, v->vid);
 328		if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
 329		    !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags))
 330			fdb_delete_local(br, NULL, f);
 331		fdb_insert(br, NULL, newaddr, v->vid);
 332	}
 333out:
 334	spin_unlock_bh(&br->hash_lock);
 335}
 336
 337void br_fdb_cleanup(struct work_struct *work)
 338{
 339	struct net_bridge *br = container_of(work, struct net_bridge,
 340					     gc_work.work);
 341	struct net_bridge_fdb_entry *f = NULL;
 342	unsigned long delay = hold_time(br);
 343	unsigned long work_delay = delay;
 344	unsigned long now = jiffies;
 345
 346	/* this part is tricky, in order to avoid blocking learning and
 347	 * consequently forwarding, we rely on rcu to delete objects with
 348	 * delayed freeing allowing us to continue traversing
 349	 */
 350	rcu_read_lock();
 351	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 352		unsigned long this_timer;
 353
 354		if (test_bit(BR_FDB_STATIC, &f->flags) ||
 355		    test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags))
 356			continue;
 357		this_timer = f->updated + delay;
 358		if (time_after(this_timer, now)) {
 359			work_delay = min(work_delay, this_timer - now);
 360		} else {
 361			spin_lock_bh(&br->hash_lock);
 362			if (!hlist_unhashed(&f->fdb_node))
 363				fdb_delete(br, f, true);
 364			spin_unlock_bh(&br->hash_lock);
 365		}
 366	}
 367	rcu_read_unlock();
 368
 369	/* Cleanup minimum 10 milliseconds apart */
 370	work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
 371	mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
 372}
 373
 374/* Completely flush all dynamic entries in forwarding database.*/
 375void br_fdb_flush(struct net_bridge *br)
 376{
 377	struct net_bridge_fdb_entry *f;
 378	struct hlist_node *tmp;
 379
 380	spin_lock_bh(&br->hash_lock);
 381	hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
 382		if (!test_bit(BR_FDB_STATIC, &f->flags))
 383			fdb_delete(br, f, true);
 384	}
 385	spin_unlock_bh(&br->hash_lock);
 386}
 387
 388/* Flush all entries referring to a specific port.
 389 * if do_all is set also flush static entries
 390 * if vid is set delete all entries that match the vlan_id
 391 */
 392void br_fdb_delete_by_port(struct net_bridge *br,
 393			   const struct net_bridge_port *p,
 394			   u16 vid,
 395			   int do_all)
 396{
 397	struct net_bridge_fdb_entry *f;
 398	struct hlist_node *tmp;
 399
 400	spin_lock_bh(&br->hash_lock);
 401	hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
 402		if (f->dst != p)
 403			continue;
 404
 405		if (!do_all)
 406			if (test_bit(BR_FDB_STATIC, &f->flags) ||
 407			    (vid && f->key.vlan_id != vid))
 408				continue;
 409
 410		if (test_bit(BR_FDB_LOCAL, &f->flags))
 411			fdb_delete_local(br, p, f);
 412		else
 413			fdb_delete(br, f, true);
 414	}
 415	spin_unlock_bh(&br->hash_lock);
 416}
 417
 418#if IS_ENABLED(CONFIG_ATM_LANE)
 419/* Interface used by ATM LANE hook to test
 420 * if an addr is on some other bridge port */
 421int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 422{
 423	struct net_bridge_fdb_entry *fdb;
 424	struct net_bridge_port *port;
 425	int ret;
 426
 427	rcu_read_lock();
 428	port = br_port_get_rcu(dev);
 429	if (!port)
 430		ret = 0;
 431	else {
 432		fdb = br_fdb_find_rcu(port->br, addr, 0);
 433		ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 434			fdb->dst->state == BR_STATE_FORWARDING;
 435	}
 436	rcu_read_unlock();
 437
 438	return ret;
 439}
 440#endif /* CONFIG_ATM_LANE */
 441
 442/*
 443 * Fill buffer with forwarding table records in
 444 * the API format.
 445 */
 446int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 447		   unsigned long maxnum, unsigned long skip)
 448{
 449	struct net_bridge_fdb_entry *f;
 450	struct __fdb_entry *fe = buf;
 451	int num = 0;
 452
 453	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 454
 455	rcu_read_lock();
 456	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 457		if (num >= maxnum)
 458			break;
 459
 460		if (has_expired(br, f))
 461			continue;
 462
 463		/* ignore pseudo entry for local MAC address */
 464		if (!f->dst)
 465			continue;
 466
 467		if (skip) {
 468			--skip;
 469			continue;
 470		}
 471
 472		/* convert from internal format to API */
 473		memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN);
 474
 475		/* due to ABI compat need to split into hi/lo */
 476		fe->port_no = f->dst->port_no;
 477		fe->port_hi = f->dst->port_no >> 8;
 478
 479		fe->is_local = test_bit(BR_FDB_LOCAL, &f->flags);
 480		if (!test_bit(BR_FDB_STATIC, &f->flags))
 481			fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 482		++fe;
 483		++num;
 484	}
 485	rcu_read_unlock();
 486
 487	return num;
 488}
 489
 490static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br,
 491					       struct net_bridge_port *source,
 492					       const unsigned char *addr,
 493					       __u16 vid,
 494					       unsigned long flags)
 495{
 496	struct net_bridge_fdb_entry *fdb;
 497
 498	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 499	if (fdb) {
 500		memcpy(fdb->key.addr.addr, addr, ETH_ALEN);
 501		fdb->dst = source;
 502		fdb->key.vlan_id = vid;
 503		fdb->flags = flags;
 504		fdb->updated = fdb->used = jiffies;
 505		if (rhashtable_lookup_insert_fast(&br->fdb_hash_tbl,
 506						  &fdb->rhnode,
 507						  br_fdb_rht_params)) {
 508			kmem_cache_free(br_fdb_cache, fdb);
 509			fdb = NULL;
 510		} else {
 511			hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list);
 512		}
 513	}
 514	return fdb;
 515}
 516
 517static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 518		  const unsigned char *addr, u16 vid)
 519{
 520	struct net_bridge_fdb_entry *fdb;
 521
 522	if (!is_valid_ether_addr(addr))
 523		return -EINVAL;
 524
 525	fdb = br_fdb_find(br, addr, vid);
 526	if (fdb) {
 527		/* it is okay to have multiple ports with same
 528		 * address, just use the first one.
 529		 */
 530		if (test_bit(BR_FDB_LOCAL, &fdb->flags))
 531			return 0;
 532		br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
 533		       source ? source->dev->name : br->dev->name, addr, vid);
 534		fdb_delete(br, fdb, true);
 535	}
 536
 537	fdb = fdb_create(br, source, addr, vid,
 538			 BIT(BR_FDB_LOCAL) | BIT(BR_FDB_STATIC));
 539	if (!fdb)
 540		return -ENOMEM;
 541
 542	fdb_add_hw_addr(br, addr);
 543	fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 544	return 0;
 545}
 546
 547/* Add entry for local address of interface */
 548int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 549		  const unsigned char *addr, u16 vid)
 550{
 551	int ret;
 552
 553	spin_lock_bh(&br->hash_lock);
 554	ret = fdb_insert(br, source, addr, vid);
 555	spin_unlock_bh(&br->hash_lock);
 556	return ret;
 557}
 558
 559void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 560		   const unsigned char *addr, u16 vid, unsigned long flags)
 561{
 562	struct net_bridge_fdb_entry *fdb;
 563	bool fdb_modified = false;
 564
 565	/* some users want to always flood. */
 566	if (hold_time(br) == 0)
 567		return;
 568
 569	fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 570	if (likely(fdb)) {
 571		/* attempt to update an entry for a local interface */
 572		if (unlikely(test_bit(BR_FDB_LOCAL, &fdb->flags))) {
 573			if (net_ratelimit())
 574				br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 575					source->dev->name, addr, vid);
 576		} else {
 577			unsigned long now = jiffies;
 578
 579			/* fastpath: update of existing entry */
 580			if (unlikely(source != fdb->dst &&
 581				     !test_bit(BR_FDB_STICKY, &fdb->flags))) {
 582				fdb->dst = source;
 583				fdb_modified = true;
 584				/* Take over HW learned entry */
 585				if (unlikely(test_bit(BR_FDB_ADDED_BY_EXT_LEARN,
 586						      &fdb->flags)))
 587					clear_bit(BR_FDB_ADDED_BY_EXT_LEARN,
 588						  &fdb->flags);
 589			}
 590			if (now != fdb->updated)
 591				fdb->updated = now;
 592			if (unlikely(test_bit(BR_FDB_ADDED_BY_USER, &flags)))
 593				set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
 594			if (unlikely(fdb_modified)) {
 595				trace_br_fdb_update(br, source, addr, vid, flags);
 596				fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 597			}
 598		}
 599	} else {
 600		spin_lock(&br->hash_lock);
 601		fdb = fdb_create(br, source, addr, vid, flags);
 602		if (fdb) {
 603			trace_br_fdb_update(br, source, addr, vid, flags);
 604			fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 605		}
 606		/* else  we lose race and someone else inserts
 607		 * it first, don't bother updating
 608		 */
 609		spin_unlock(&br->hash_lock);
 610	}
 611}
 612
 613static int fdb_to_nud(const struct net_bridge *br,
 614		      const struct net_bridge_fdb_entry *fdb)
 615{
 616	if (test_bit(BR_FDB_LOCAL, &fdb->flags))
 617		return NUD_PERMANENT;
 618	else if (test_bit(BR_FDB_STATIC, &fdb->flags))
 619		return NUD_NOARP;
 620	else if (has_expired(br, fdb))
 621		return NUD_STALE;
 622	else
 623		return NUD_REACHABLE;
 624}
 625
 626static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 627			 const struct net_bridge_fdb_entry *fdb,
 628			 u32 portid, u32 seq, int type, unsigned int flags)
 629{
 630	unsigned long now = jiffies;
 631	struct nda_cacheinfo ci;
 632	struct nlmsghdr *nlh;
 633	struct ndmsg *ndm;
 634
 635	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 636	if (nlh == NULL)
 637		return -EMSGSIZE;
 638
 639	ndm = nlmsg_data(nlh);
 640	ndm->ndm_family	 = AF_BRIDGE;
 641	ndm->ndm_pad1    = 0;
 642	ndm->ndm_pad2    = 0;
 643	ndm->ndm_flags	 = 0;
 644	ndm->ndm_type	 = 0;
 645	ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 646	ndm->ndm_state   = fdb_to_nud(br, fdb);
 647
 648	if (test_bit(BR_FDB_OFFLOADED, &fdb->flags))
 649		ndm->ndm_flags |= NTF_OFFLOADED;
 650	if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
 651		ndm->ndm_flags |= NTF_EXT_LEARNED;
 652	if (test_bit(BR_FDB_STICKY, &fdb->flags))
 653		ndm->ndm_flags |= NTF_STICKY;
 654
 655	if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr))
 656		goto nla_put_failure;
 657	if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 658		goto nla_put_failure;
 659	ci.ndm_used	 = jiffies_to_clock_t(now - fdb->used);
 660	ci.ndm_confirmed = 0;
 661	ci.ndm_updated	 = jiffies_to_clock_t(now - fdb->updated);
 662	ci.ndm_refcnt	 = 0;
 663	if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 664		goto nla_put_failure;
 665
 666	if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16),
 667					&fdb->key.vlan_id))
 668		goto nla_put_failure;
 669
 670	nlmsg_end(skb, nlh);
 671	return 0;
 672
 673nla_put_failure:
 674	nlmsg_cancel(skb, nlh);
 675	return -EMSGSIZE;
 676}
 677
 678static inline size_t fdb_nlmsg_size(void)
 679{
 680	return NLMSG_ALIGN(sizeof(struct ndmsg))
 681		+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 682		+ nla_total_size(sizeof(u32)) /* NDA_MASTER */
 683		+ nla_total_size(sizeof(u16)) /* NDA_VLAN */
 684		+ nla_total_size(sizeof(struct nda_cacheinfo));
 685}
 686
 687static void fdb_notify(struct net_bridge *br,
 688		       const struct net_bridge_fdb_entry *fdb, int type,
 689		       bool swdev_notify)
 690{
 691	struct net *net = dev_net(br->dev);
 692	struct sk_buff *skb;
 693	int err = -ENOBUFS;
 694
 695	if (swdev_notify)
 696		br_switchdev_fdb_notify(fdb, type);
 697
 698	skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 699	if (skb == NULL)
 700		goto errout;
 701
 702	err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 703	if (err < 0) {
 704		/* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 705		WARN_ON(err == -EMSGSIZE);
 706		kfree_skb(skb);
 707		goto errout;
 708	}
 709	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 710	return;
 711errout:
 712	rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 713}
 714
 715/* Dump information about entries, in response to GETNEIGH */
 716int br_fdb_dump(struct sk_buff *skb,
 717		struct netlink_callback *cb,
 718		struct net_device *dev,
 719		struct net_device *filter_dev,
 720		int *idx)
 721{
 722	struct net_bridge *br = netdev_priv(dev);
 723	struct net_bridge_fdb_entry *f;
 724	int err = 0;
 725
 726	if (!(dev->priv_flags & IFF_EBRIDGE))
 727		return err;
 728
 729	if (!filter_dev) {
 730		err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 731		if (err < 0)
 732			return err;
 733	}
 734
 735	rcu_read_lock();
 736	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 737		if (*idx < cb->args[2])
 738			goto skip;
 739		if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
 740			if (filter_dev != dev)
 741				goto skip;
 742			/* !f->dst is a special case for bridge
 743			 * It means the MAC belongs to the bridge
 744			 * Therefore need a little more filtering
 745			 * we only want to dump the !f->dst case
 746			 */
 747			if (f->dst)
 748				goto skip;
 749		}
 750		if (!filter_dev && f->dst)
 751			goto skip;
 752
 753		err = fdb_fill_info(skb, br, f,
 754				    NETLINK_CB(cb->skb).portid,
 755				    cb->nlh->nlmsg_seq,
 756				    RTM_NEWNEIGH,
 757				    NLM_F_MULTI);
 758		if (err < 0)
 759			break;
 760skip:
 761		*idx += 1;
 762	}
 763	rcu_read_unlock();
 764
 765	return err;
 766}
 767
 768int br_fdb_get(struct sk_buff *skb,
 769	       struct nlattr *tb[],
 770	       struct net_device *dev,
 771	       const unsigned char *addr,
 772	       u16 vid, u32 portid, u32 seq,
 773	       struct netlink_ext_ack *extack)
 774{
 775	struct net_bridge *br = netdev_priv(dev);
 776	struct net_bridge_fdb_entry *f;
 777	int err = 0;
 778
 779	rcu_read_lock();
 780	f = br_fdb_find_rcu(br, addr, vid);
 781	if (!f) {
 782		NL_SET_ERR_MSG(extack, "Fdb entry not found");
 783		err = -ENOENT;
 784		goto errout;
 785	}
 786
 787	err = fdb_fill_info(skb, br, f, portid, seq,
 788			    RTM_NEWNEIGH, 0);
 789errout:
 790	rcu_read_unlock();
 791	return err;
 792}
 793
 794/* Update (create or replace) forwarding database entry */
 795static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 796			 const u8 *addr, u16 state, u16 flags, u16 vid,
 797			 u8 ndm_flags)
 798{
 799	bool is_sticky = !!(ndm_flags & NTF_STICKY);
 800	struct net_bridge_fdb_entry *fdb;
 801	bool modified = false;
 802
 803	/* If the port cannot learn allow only local and static entries */
 804	if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 805	    !(source->state == BR_STATE_LEARNING ||
 806	      source->state == BR_STATE_FORWARDING))
 807		return -EPERM;
 808
 809	if (!source && !(state & NUD_PERMANENT)) {
 810		pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 811			br->dev->name);
 812		return -EINVAL;
 813	}
 814
 815	if (is_sticky && (state & NUD_PERMANENT))
 816		return -EINVAL;
 817
 818	fdb = br_fdb_find(br, addr, vid);
 819	if (fdb == NULL) {
 820		if (!(flags & NLM_F_CREATE))
 821			return -ENOENT;
 822
 823		fdb = fdb_create(br, source, addr, vid, 0);
 824		if (!fdb)
 825			return -ENOMEM;
 826
 827		modified = true;
 828	} else {
 829		if (flags & NLM_F_EXCL)
 830			return -EEXIST;
 831
 832		if (fdb->dst != source) {
 833			fdb->dst = source;
 834			modified = true;
 835		}
 836	}
 837
 838	if (fdb_to_nud(br, fdb) != state) {
 839		if (state & NUD_PERMANENT) {
 840			set_bit(BR_FDB_LOCAL, &fdb->flags);
 841			if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
 842				fdb_add_hw_addr(br, addr);
 843		} else if (state & NUD_NOARP) {
 844			clear_bit(BR_FDB_LOCAL, &fdb->flags);
 845			if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
 846				fdb_add_hw_addr(br, addr);
 847		} else {
 848			clear_bit(BR_FDB_LOCAL, &fdb->flags);
 849			if (test_and_clear_bit(BR_FDB_STATIC, &fdb->flags))
 850				fdb_del_hw_addr(br, addr);
 851		}
 852
 853		modified = true;
 854	}
 855
 856	if (is_sticky != test_bit(BR_FDB_STICKY, &fdb->flags)) {
 857		change_bit(BR_FDB_STICKY, &fdb->flags);
 858		modified = true;
 859	}
 860
 861	set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
 862
 863	fdb->used = jiffies;
 864	if (modified) {
 865		fdb->updated = jiffies;
 866		fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 867	}
 868
 869	return 0;
 870}
 871
 872static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 873			struct net_bridge_port *p, const unsigned char *addr,
 874			u16 nlh_flags, u16 vid)
 875{
 876	int err = 0;
 877
 878	if (ndm->ndm_flags & NTF_USE) {
 879		if (!p) {
 880			pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 881				br->dev->name);
 882			return -EINVAL;
 883		}
 884		if (!nbp_state_should_learn(p))
 885			return 0;
 886
 887		local_bh_disable();
 888		rcu_read_lock();
 889		br_fdb_update(br, p, addr, vid, BIT(BR_FDB_ADDED_BY_USER));
 890		rcu_read_unlock();
 891		local_bh_enable();
 892	} else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
 893		err = br_fdb_external_learn_add(br, p, addr, vid, true);
 894	} else {
 895		spin_lock_bh(&br->hash_lock);
 896		err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 897				    nlh_flags, vid, ndm->ndm_flags);
 898		spin_unlock_bh(&br->hash_lock);
 899	}
 900
 901	return err;
 902}
 903
 904/* Add new permanent fdb entry with RTM_NEWNEIGH */
 905int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 906	       struct net_device *dev,
 907	       const unsigned char *addr, u16 vid, u16 nlh_flags,
 908	       struct netlink_ext_ack *extack)
 909{
 910	struct net_bridge_vlan_group *vg;
 911	struct net_bridge_port *p = NULL;
 912	struct net_bridge_vlan *v;
 913	struct net_bridge *br = NULL;
 914	int err = 0;
 915
 916	trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);
 917
 918	if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 919		pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 920		return -EINVAL;
 921	}
 922
 923	if (is_zero_ether_addr(addr)) {
 924		pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 925		return -EINVAL;
 926	}
 927
 928	if (dev->priv_flags & IFF_EBRIDGE) {
 929		br = netdev_priv(dev);
 930		vg = br_vlan_group(br);
 931	} else {
 932		p = br_port_get_rtnl(dev);
 933		if (!p) {
 934			pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 935				dev->name);
 936			return -EINVAL;
 937		}
 938		br = p->br;
 939		vg = nbp_vlan_group(p);
 940	}
 941
 942	if (vid) {
 943		v = br_vlan_find(vg, vid);
 944		if (!v || !br_vlan_should_use(v)) {
 945			pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 946			return -EINVAL;
 947		}
 948
 949		/* VID was specified, so use it. */
 950		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 951	} else {
 952		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 953		if (err || !vg || !vg->num_vlans)
 954			goto out;
 955
 956		/* We have vlans configured on this port and user didn't
 957		 * specify a VLAN.  To be nice, add/update entry for every
 958		 * vlan on this port.
 959		 */
 960		list_for_each_entry(v, &vg->vlan_list, vlist) {
 961			if (!br_vlan_should_use(v))
 962				continue;
 963			err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 964			if (err)
 965				goto out;
 966		}
 967	}
 968
 969out:
 970	return err;
 971}
 972
 973static int fdb_delete_by_addr_and_port(struct net_bridge *br,
 974				       const struct net_bridge_port *p,
 975				       const u8 *addr, u16 vlan)
 976{
 977	struct net_bridge_fdb_entry *fdb;
 978
 979	fdb = br_fdb_find(br, addr, vlan);
 980	if (!fdb || fdb->dst != p)
 981		return -ENOENT;
 982
 983	fdb_delete(br, fdb, true);
 984
 985	return 0;
 986}
 987
 988static int __br_fdb_delete(struct net_bridge *br,
 989			   const struct net_bridge_port *p,
 990			   const unsigned char *addr, u16 vid)
 991{
 992	int err;
 993
 994	spin_lock_bh(&br->hash_lock);
 995	err = fdb_delete_by_addr_and_port(br, p, addr, vid);
 996	spin_unlock_bh(&br->hash_lock);
 997
 998	return err;
 999}
1000
1001/* Remove neighbor entry with RTM_DELNEIGH */
1002int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
1003		  struct net_device *dev,
1004		  const unsigned char *addr, u16 vid)
1005{
1006	struct net_bridge_vlan_group *vg;
1007	struct net_bridge_port *p = NULL;
1008	struct net_bridge_vlan *v;
1009	struct net_bridge *br;
1010	int err;
1011
1012	if (dev->priv_flags & IFF_EBRIDGE) {
1013		br = netdev_priv(dev);
1014		vg = br_vlan_group(br);
1015	} else {
1016		p = br_port_get_rtnl(dev);
1017		if (!p) {
1018			pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1019				dev->name);
1020			return -EINVAL;
1021		}
1022		vg = nbp_vlan_group(p);
1023		br = p->br;
1024	}
1025
1026	if (vid) {
1027		v = br_vlan_find(vg, vid);
1028		if (!v) {
1029			pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1030			return -EINVAL;
1031		}
1032
1033		err = __br_fdb_delete(br, p, addr, vid);
1034	} else {
1035		err = -ENOENT;
1036		err &= __br_fdb_delete(br, p, addr, 0);
1037		if (!vg || !vg->num_vlans)
1038			return err;
1039
1040		list_for_each_entry(v, &vg->vlan_list, vlist) {
1041			if (!br_vlan_should_use(v))
1042				continue;
1043			err &= __br_fdb_delete(br, p, addr, v->vid);
1044		}
1045	}
1046
1047	return err;
1048}
1049
1050int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1051{
1052	struct net_bridge_fdb_entry *f, *tmp;
1053	int err = 0;
1054
1055	ASSERT_RTNL();
1056
1057	/* the key here is that static entries change only under rtnl */
1058	rcu_read_lock();
1059	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1060		/* We only care for static entries */
1061		if (!test_bit(BR_FDB_STATIC, &f->flags))
1062			continue;
1063		err = dev_uc_add(p->dev, f->key.addr.addr);
1064		if (err)
1065			goto rollback;
1066	}
1067done:
1068	rcu_read_unlock();
1069
1070	return err;
1071
1072rollback:
1073	hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) {
1074		/* We only care for static entries */
1075		if (!test_bit(BR_FDB_STATIC, &tmp->flags))
1076			continue;
1077		if (tmp == f)
1078			break;
1079		dev_uc_del(p->dev, tmp->key.addr.addr);
1080	}
1081
1082	goto done;
1083}
1084
1085void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1086{
1087	struct net_bridge_fdb_entry *f;
1088
1089	ASSERT_RTNL();
1090
1091	rcu_read_lock();
1092	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1093		/* We only care for static entries */
1094		if (!test_bit(BR_FDB_STATIC, &f->flags))
1095			continue;
1096
1097		dev_uc_del(p->dev, f->key.addr.addr);
1098	}
1099	rcu_read_unlock();
1100}
1101
1102int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1103			      const unsigned char *addr, u16 vid,
1104			      bool swdev_notify)
1105{
1106	struct net_bridge_fdb_entry *fdb;
1107	bool modified = false;
1108	int err = 0;
1109
1110	trace_br_fdb_external_learn_add(br, p, addr, vid);
1111
1112	spin_lock_bh(&br->hash_lock);
1113
1114	fdb = br_fdb_find(br, addr, vid);
1115	if (!fdb) {
1116		unsigned long flags = BIT(BR_FDB_ADDED_BY_EXT_LEARN);
1117
1118		if (swdev_notify)
1119			flags |= BIT(BR_FDB_ADDED_BY_USER);
1120		fdb = fdb_create(br, p, addr, vid, flags);
1121		if (!fdb) {
1122			err = -ENOMEM;
1123			goto err_unlock;
1124		}
1125		fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1126	} else {
1127		fdb->updated = jiffies;
1128
1129		if (fdb->dst != p) {
1130			fdb->dst = p;
1131			modified = true;
1132		}
1133
1134		if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) {
1135			/* Refresh entry */
1136			fdb->used = jiffies;
1137		} else if (!test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags)) {
1138			/* Take over SW learned entry */
1139			set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags);
1140			modified = true;
1141		}
1142
1143		if (swdev_notify)
1144			set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
1145
1146		if (modified)
1147			fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1148	}
1149
1150err_unlock:
1151	spin_unlock_bh(&br->hash_lock);
1152
1153	return err;
1154}
1155
1156int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1157			      const unsigned char *addr, u16 vid,
1158			      bool swdev_notify)
1159{
1160	struct net_bridge_fdb_entry *fdb;
1161	int err = 0;
1162
1163	spin_lock_bh(&br->hash_lock);
1164
1165	fdb = br_fdb_find(br, addr, vid);
1166	if (fdb && test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
1167		fdb_delete(br, fdb, swdev_notify);
1168	else
1169		err = -ENOENT;
1170
1171	spin_unlock_bh(&br->hash_lock);
1172
1173	return err;
1174}
1175
1176void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1177			  const unsigned char *addr, u16 vid, bool offloaded)
1178{
1179	struct net_bridge_fdb_entry *fdb;
1180
1181	spin_lock_bh(&br->hash_lock);
1182
1183	fdb = br_fdb_find(br, addr, vid);
1184	if (fdb && offloaded != test_bit(BR_FDB_OFFLOADED, &fdb->flags))
1185		change_bit(BR_FDB_OFFLOADED, &fdb->flags);
1186
1187	spin_unlock_bh(&br->hash_lock);
1188}
1189
1190void br_fdb_clear_offload(const struct net_device *dev, u16 vid)
1191{
1192	struct net_bridge_fdb_entry *f;
1193	struct net_bridge_port *p;
1194
1195	ASSERT_RTNL();
1196
1197	p = br_port_get_rtnl(dev);
1198	if (!p)
1199		return;
1200
1201	spin_lock_bh(&p->br->hash_lock);
1202	hlist_for_each_entry(f, &p->br->fdb_list, fdb_node) {
1203		if (f->dst == p && f->key.vlan_id == vid)
1204			clear_bit(BR_FDB_OFFLOADED, &f->flags);
1205	}
1206	spin_unlock_bh(&p->br->hash_lock);
1207}
1208EXPORT_SYMBOL_GPL(br_fdb_clear_offload);