[net-next-2.6.git] / net / bridge / br_fdb.c

/*
 *	Forwarding database
 *	Linux ethernet bridge
 *
 *	Authors:
 *	Lennert Buytenhek		<buytenh@gnu.org>
 *
 *	$Id: br_fdb.c,v 1.6 2002/01/17 00:57:07 davem Exp $
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/times.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <asm/atomic.h>
#include <asm/unaligned.h>
#include "br_private.h"

static struct kmem_cache *br_fdb_cache __read_mostly;
static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
		      const unsigned char *addr);

static u32 fdb_salt __read_mostly;

int __init br_fdb_init(void)
{
	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
					 sizeof(struct net_bridge_fdb_entry),
					 0,
					 SLAB_HWCACHE_ALIGN, NULL);
	if (!br_fdb_cache)
		return -ENOMEM;

	get_random_bytes(&fdb_salt, sizeof(fdb_salt));
	return 0;
}

void __exit br_fdb_fini(void)
{
	kmem_cache_destroy(br_fdb_cache);
}


/* if topology_changing then use forward_delay (default 15 sec)
 * otherwise keep longer (default 5 minutes)
 */
static inline unsigned long hold_time(const struct net_bridge *br)
{
	return br->topology_change ? br->forward_delay : br->ageing_time;
}

static inline int has_expired(const struct net_bridge *br,
				  const struct net_bridge_fdb_entry *fdb)
{
	return !fdb->is_static
		&& time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
}

static inline int br_mac_hash(const unsigned char *mac)
{
	/* use 1 byte of OUI cnd 3 bytes of NIC */
	u32 key = get_unaligned((u32 *)(mac + 2));
	return jhash_1word(key, fdb_salt) & (BR_HASH_SIZE - 1);
}

static inline void fdb_delete(struct net_bridge_fdb_entry *f)
{
	hlist_del_rcu(&f->hlist);
	br_fdb_put(f);
}

void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
{
	struct net_bridge *br = p->br;
	int i;

	spin_lock_bh(&br->hash_lock);

	/* Search all chains since old address/hash is unknown */
	for (i = 0; i < BR_HASH_SIZE; i++) {
		struct hlist_node *h;
		hlist_for_each(h, &br->hash[i]) {
			struct net_bridge_fdb_entry *f;

			f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
			if (f->dst == p && f->is_local) {
				/* maybe another port has same hw addr? */
				struct net_bridge_port *op;
				list_for_each_entry(op, &br->port_list, list) {
					if (op != p &&
					    !compare_ether_addr(op->dev->dev_addr,
								f->addr.addr)) {
						f->dst = op;
						goto insert;
					}
				}

				/* delete old one */
				fdb_delete(f);
				goto insert;
			}
		}
	}
 insert:
	/* insert new address,  may fail if invalid address or dup. */
	fdb_insert(br, p, newaddr);

	spin_unlock_bh(&br->hash_lock);
}

void br_fdb_cleanup(unsigned long _data)
{
	struct net_bridge *br = (struct net_bridge *)_data;
	unsigned long delay = hold_time(br);
	unsigned long next_timer = jiffies + br->forward_delay;
	int i;

	spin_lock_bh(&br->hash_lock);
	for (i = 0; i < BR_HASH_SIZE; i++) {
		struct net_bridge_fdb_entry *f;
		struct hlist_node *h, *n;

		hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
			unsigned long this_timer;
			if (f->is_static)
				continue;
			this_timer = f->ageing_timer + delay;
			if (time_before_eq(this_timer, jiffies))
				fdb_delete(f);
			else if (this_timer < next_timer)
				next_timer = this_timer;
		}
	}
	spin_unlock_bh(&br->hash_lock);

	/* Add HZ/4 to ensure we round the jiffies upwards to be after the next
	 * timer, otherwise we might round down and will have no-op run. */
	mod_timer(&br->gc_timer, round_jiffies(next_timer + HZ/4));
}

/* Completely flush all dynamic entries in forwarding database.*/
void br_fdb_flush(struct net_bridge *br)
{
	int i;

	spin_lock_bh(&br->hash_lock);
	for (i = 0; i < BR_HASH_SIZE; i++) {
		struct net_bridge_fdb_entry *f;
		struct hlist_node *h, *n;
		hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
			if (!f->is_static)
				fdb_delete(f);
		}
	}
	spin_unlock_bh(&br->hash_lock);
}

/* Flush all entries refering to a specific port.
 * if do_all is set also flush static entries
 */
void br_fdb_delete_by_port(struct net_bridge *br,
			   const struct net_bridge_port *p,
			   int do_all)
{
	int i;

	spin_lock_bh(&br->hash_lock);
	for (i = 0; i < BR_HASH_SIZE; i++) {
		struct hlist_node *h, *g;

		hlist_for_each_safe(h, g, &br->hash[i]) {
			struct net_bridge_fdb_entry *f
				= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
			if (f->dst != p)
				continue;

			if (f->is_static && !do_all)
				continue;
			/*
			 * if multiple ports all have the same device address
			 * then when one port is deleted, assign
			 * the local entry to other port
			 */
			if (f->is_local) {
				struct net_bridge_port *op;
				list_for_each_entry(op, &br->port_list, list) {
					if (op != p &&
					    !compare_ether_addr(op->dev->dev_addr,
								f->addr.addr)) {
						f->dst = op;
						goto skip_delete;
					}
				}
			}

			fdb_delete(f);
		skip_delete: ;
		}
	}
	spin_unlock_bh(&br->hash_lock);
}

/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
					  const unsigned char *addr)
{
	struct hlist_node *h;
	struct net_bridge_fdb_entry *fdb;

	hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
		if (!compare_ether_addr(fdb->addr.addr, addr)) {
			if (unlikely(has_expired(br, fdb)))
				break;
			return fdb;
		}
	}

	return NULL;
}

/* Interface used by ATM hook that keeps a ref count */
struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br,
					unsigned char *addr)
{
	struct net_bridge_fdb_entry *fdb;

	rcu_read_lock();
	fdb = __br_fdb_get(br, addr);
	if (fdb && !atomic_inc_not_zero(&fdb->use_count))
		fdb = NULL;
	rcu_read_unlock();
	return fdb;
}

static void fdb_rcu_free(struct rcu_head *head)
{
	struct net_bridge_fdb_entry *ent
		= container_of(head, struct net_bridge_fdb_entry, rcu);
	kmem_cache_free(br_fdb_cache, ent);
}

/* Set entry up for deletion with RCU  */
void br_fdb_put(struct net_bridge_fdb_entry *ent)
{
	if (atomic_dec_and_test(&ent->use_count))
		call_rcu(&ent->rcu, fdb_rcu_free);
}

/*
 * Fill buffer with forwarding table records in
 * the API format.
 */
int br_fdb_fillbuf(struct net_bridge *br, void *buf,
		   unsigned long maxnum, unsigned long skip)
{
	struct __fdb_entry *fe = buf;
	int i, num = 0;
	struct hlist_node *h;
	struct net_bridge_fdb_entry *f;

	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));

	rcu_read_lock();
	for (i = 0; i < BR_HASH_SIZE; i++) {
		hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
			if (num >= maxnum)
				goto out;

			if (has_expired(br, f))
				continue;

			if (skip) {
				--skip;
				continue;
			}

			/* convert from internal format to API */
			memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
			fe->port_no = f->dst->port_no;
			fe->is_local = f->is_local;
			if (!f->is_static)
				fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer);
			++fe;
			++num;
		}
	}

 out:
	rcu_read_unlock();

	return num;
}

static inline struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
						    const unsigned char *addr)
{
	struct hlist_node *h;
	struct net_bridge_fdb_entry *fdb;

	hlist_for_each_entry_rcu(fdb, h, head, hlist) {
		if (!compare_ether_addr(fdb->addr.addr, addr))
			return fdb;
	}
	return NULL;
}

static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
					       struct net_bridge_port *source,
					       const unsigned char *addr,
					       int is_local)
{
	struct net_bridge_fdb_entry *fdb;

	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
	if (fdb) {
		memcpy(fdb->addr.addr, addr, ETH_ALEN);
		atomic_set(&fdb->use_count, 1);
		hlist_add_head_rcu(&fdb->hlist, head);

		fdb->dst = source;
		fdb->is_local = is_local;
		fdb->is_static = is_local;
		fdb->ageing_timer = jiffies;
	}
	return fdb;
}

static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
		  const unsigned char *addr)
{
	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	struct net_bridge_fdb_entry *fdb;

	if (!is_valid_ether_addr(addr))
		return -EINVAL;

	fdb = fdb_find(head, addr);
	if (fdb) {
		/* it is okay to have multiple ports with same
		 * address, just use the first one.
		 */
		if (fdb->is_local)
			return 0;

		printk(KERN_WARNING "%s adding interface with same address "
		       "as a received packet\n",
		       source->dev->name);
		fdb_delete(fdb);
	}

	if (!fdb_create(head, source, addr, 1))
		return -ENOMEM;

	return 0;
}

int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
		  const unsigned char *addr)
{
	int ret;

	spin_lock_bh(&br->hash_lock);
	ret = fdb_insert(br, source, addr);
	spin_unlock_bh(&br->hash_lock);
	return ret;
}

void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
		   const unsigned char *addr)
{
	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	struct net_bridge_fdb_entry *fdb;

	/* some users want to always flood. */
	if (hold_time(br) == 0)
		return;

	fdb = fdb_find(head, addr);
	if (likely(fdb)) {
		/* attempt to update an entry for a local interface */
		if (unlikely(fdb->is_local)) {
			if (net_ratelimit())
				printk(KERN_WARNING "%s: received packet with "
				       " own address as source address\n",
				       source->dev->name);
		} else {
			/* fastpath: update of existing entry */
			fdb->dst = source;
			fdb->ageing_timer = jiffies;
		}
	} else {
		spin_lock(&br->hash_lock);
		if (!fdb_find(head, addr))
			fdb_create(head, source, addr, 0);
		/* else  we lose race and someone else inserts
		 * it first, don't bother updating
		 */
		spin_unlock(&br->hash_lock);
	}
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Forwarding database
	3	* Linux ethernet bridge
	4	*
	5	* Authors:
	6	* Lennert Buytenhek <buytenh@gnu.org>
	7	*
	8	* $Id: br_fdb.c,v 1.6 2002/01/17 00:57:07 davem Exp $
	9	*
	10	* This program is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public License
	12	* as published by the Free Software Foundation; either version
	13	* 2 of the License, or (at your option) any later version.
	14	*/
	15
	16	#include <linux/kernel.h>
	17	#include <linux/init.h>
	18	#include <linux/spinlock.h>
	19	#include <linux/times.h>
	20	#include <linux/netdevice.h>
	21	#include <linux/etherdevice.h>
	22	#include <linux/jhash.h>
3f890923	23	#include <linux/random.h>
1da177e4	24	#include <asm/atomic.h>
3f890923	25	#include <asm/unaligned.h>
1da177e4 LT	26	#include "br_private.h"
1da177e4 LT	27
e18b890b	28	static struct kmem_cache *br_fdb_cache __read_mostly;
1da177e4 LT	29	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
	30	const unsigned char *addr);
	31
3f890923 SH	32	static u32 fdb_salt __read_mostly;
3f890923 SH	33
87a596e0	34	int __init br_fdb_init(void)
1da177e4 LT	35	{
	36	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
	37	sizeof(struct net_bridge_fdb_entry),
	38	0,
20c2df83	39	SLAB_HWCACHE_ALIGN, NULL);
87a596e0 AM	40	if (!br_fdb_cache)
	41	return -ENOMEM;
	42
3f890923	43	get_random_bytes(&fdb_salt, sizeof(fdb_salt));
87a596e0	44	return 0;
1da177e4 LT	45	}
	46
	47	void __exit br_fdb_fini(void)
	48	{
	49	kmem_cache_destroy(br_fdb_cache);
	50	}
	51
	52
	53	/* if topology_changing then use forward_delay (default 15 sec)
	54	* otherwise keep longer (default 5 minutes)
	55	*/
3f890923	56	static inline unsigned long hold_time(const struct net_bridge *br)
1da177e4 LT	57	{
	58	return br->topology_change ? br->forward_delay : br->ageing_time;
	59	}
	60
3f890923	61	static inline int has_expired(const struct net_bridge *br,
1da177e4 LT	62	const struct net_bridge_fdb_entry *fdb)
1da177e4 LT	63	{
9d6f229f	64	return !fdb->is_static
1da177e4 LT	65	&& time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
	66	}
	67
3f890923	68	static inline int br_mac_hash(const unsigned char *mac)
1da177e4	69	{
3f890923 SH	70	/* use 1 byte of OUI cnd 3 bytes of NIC */
	71	u32 key = get_unaligned((u32 *)(mac + 2));
	72	return jhash_1word(key, fdb_salt) & (BR_HASH_SIZE - 1);
1da177e4 LT	73	}
1da177e4 LT	74
3f890923	75	static inline void fdb_delete(struct net_bridge_fdb_entry *f)
1da177e4 LT	76	{
	77	hlist_del_rcu(&f->hlist);
	78	br_fdb_put(f);
	79	}
	80
	81	void br_fdb_changeaddr(struct net_bridge_port p, const unsigned char newaddr)
	82	{
	83	struct net_bridge *br = p->br;
	84	int i;
9d6f229f	85
1da177e4 LT	86	spin_lock_bh(&br->hash_lock);
	87
	88	/* Search all chains since old address/hash is unknown */
	89	for (i = 0; i < BR_HASH_SIZE; i++) {
	90	struct hlist_node *h;
	91	hlist_for_each(h, &br->hash[i]) {
	92	struct net_bridge_fdb_entry *f;
	93
	94	f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
	95	if (f->dst == p && f->is_local) {
	96	/* maybe another port has same hw addr? */
	97	struct net_bridge_port *op;
	98	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	99	if (op != p &&
6ede2463 SH	100	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	101	f->addr.addr)) {
1da177e4 LT	102	f->dst = op;
	103	goto insert;
	104	}
	105	}
	106
	107	/* delete old one */
	108	fdb_delete(f);
	109	goto insert;
	110	}
	111	}
	112	}
	113	insert:
	114	/* insert new address, may fail if invalid address or dup. */
	115	fdb_insert(br, p, newaddr);
	116
	117	spin_unlock_bh(&br->hash_lock);
	118	}
	119
	120	void br_fdb_cleanup(unsigned long _data)
	121	{
	122	struct net_bridge br = (struct net_bridge )_data;
	123	unsigned long delay = hold_time(br);
071f7722	124	unsigned long next_timer = jiffies + br->forward_delay;
1da177e4 LT	125	int i;
	126
	127	spin_lock_bh(&br->hash_lock);
	128	for (i = 0; i < BR_HASH_SIZE; i++) {
	129	struct net_bridge_fdb_entry *f;
	130	struct hlist_node h, n;
	131
	132	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
071f7722 BE	133	unsigned long this_timer;
	134	if (f->is_static)
	135	continue;
	136	this_timer = f->ageing_timer + delay;
	137	if (time_before_eq(this_timer, jiffies))
1da177e4	138	fdb_delete(f);
071f7722 BE	139	else if (this_timer < next_timer)
071f7722 BE	140	next_timer = this_timer;
1da177e4 LT	141	}
	142	}
	143	spin_unlock_bh(&br->hash_lock);
	144
071f7722 BE	145	/* Add HZ/4 to ensure we round the jiffies upwards to be after the next
	146	* timer, otherwise we might round down and will have no-op run. */
	147	mod_timer(&br->gc_timer, round_jiffies(next_timer + HZ/4));
1da177e4 LT	148	}
1da177e4 LT	149
9cf63747 SH	150	/* Completely flush all dynamic entries in forwarding database.*/
	151	void br_fdb_flush(struct net_bridge *br)
	152	{
	153	int i;
	154
	155	spin_lock_bh(&br->hash_lock);
	156	for (i = 0; i < BR_HASH_SIZE; i++) {
	157	struct net_bridge_fdb_entry *f;
	158	struct hlist_node h, n;
	159	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
	160	if (!f->is_static)
	161	fdb_delete(f);
	162	}
	163	}
	164	spin_unlock_bh(&br->hash_lock);
	165	}
1a620698	166
9cf63747 SH	167	/* Flush all entries refering to a specific port.
	168	* if do_all is set also flush static entries
	169	*/
1a620698 SH	170	void br_fdb_delete_by_port(struct net_bridge *br,
	171	const struct net_bridge_port *p,
	172	int do_all)
1da177e4 LT	173	{
	174	int i;
	175
	176	spin_lock_bh(&br->hash_lock);
	177	for (i = 0; i < BR_HASH_SIZE; i++) {
	178	struct hlist_node h, g;
9d6f229f	179
1da177e4 LT	180	hlist_for_each_safe(h, g, &br->hash[i]) {
	181	struct net_bridge_fdb_entry *f
	182	= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
9d6f229f	183	if (f->dst != p)
1da177e4 LT	184	continue;
1da177e4 LT	185
1a620698 SH	186	if (f->is_static && !do_all)
1a620698 SH	187	continue;
1da177e4 LT	188	/*
	189	* if multiple ports all have the same device address
	190	* then when one port is deleted, assign
	191	* the local entry to other port
	192	*/
	193	if (f->is_local) {
	194	struct net_bridge_port *op;
	195	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	196	if (op != p &&
6ede2463 SH	197	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	198	f->addr.addr)) {
1da177e4 LT	199	f->dst = op;
	200	goto skip_delete;
	201	}
	202	}
	203	}
	204
	205	fdb_delete(f);
	206	skip_delete: ;
	207	}
	208	}
	209	spin_unlock_bh(&br->hash_lock);
	210	}
	211
	212	/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
	213	struct net_bridge_fdb_entry __br_fdb_get(struct net_bridge br,
	214	const unsigned char *addr)
	215	{
	216	struct hlist_node *h;
	217	struct net_bridge_fdb_entry *fdb;
	218
	219	hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
6ede2463	220	if (!compare_ether_addr(fdb->addr.addr, addr)) {
1da177e4 LT	221	if (unlikely(has_expired(br, fdb)))
	222	break;
	223	return fdb;
	224	}
	225	}
	226
	227	return NULL;
	228	}
	229
	230	/* Interface used by ATM hook that keeps a ref count */
9d6f229f	231	struct net_bridge_fdb_entry br_fdb_get(struct net_bridge br,
1da177e4 LT	232	unsigned char *addr)
	233	{
	234	struct net_bridge_fdb_entry *fdb;
	235
	236	rcu_read_lock();
	237	fdb = __br_fdb_get(br, addr);
b19cbe2a PM	238	if (fdb && !atomic_inc_not_zero(&fdb->use_count))
b19cbe2a PM	239	fdb = NULL;
1da177e4 LT	240	rcu_read_unlock();
	241	return fdb;
	242	}
	243
	244	static void fdb_rcu_free(struct rcu_head *head)
	245	{
	246	struct net_bridge_fdb_entry *ent
	247	= container_of(head, struct net_bridge_fdb_entry, rcu);
	248	kmem_cache_free(br_fdb_cache, ent);
	249	}
	250
	251	/* Set entry up for deletion with RCU */
	252	void br_fdb_put(struct net_bridge_fdb_entry *ent)
	253	{
	254	if (atomic_dec_and_test(&ent->use_count))
	255	call_rcu(&ent->rcu, fdb_rcu_free);
	256	}
	257
	258	/*
9d6f229f	259	* Fill buffer with forwarding table records in
1da177e4 LT	260	* the API format.
	261	*/
	262	int br_fdb_fillbuf(struct net_bridge br, void buf,
	263	unsigned long maxnum, unsigned long skip)
	264	{
	265	struct __fdb_entry *fe = buf;
	266	int i, num = 0;
	267	struct hlist_node *h;
	268	struct net_bridge_fdb_entry *f;
	269
	270	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
	271
	272	rcu_read_lock();
	273	for (i = 0; i < BR_HASH_SIZE; i++) {
	274	hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
	275	if (num >= maxnum)
	276	goto out;
	277
9d6f229f	278	if (has_expired(br, f))
1da177e4 LT	279	continue;
	280
	281	if (skip) {
	282	--skip;
	283	continue;
	284	}
	285
	286	/* convert from internal format to API */
	287	memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
	288	fe->port_no = f->dst->port_no;
	289	fe->is_local = f->is_local;
	290	if (!f->is_static)
	291	fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer);
	292	++fe;
	293	++num;
	294	}
	295	}
	296
	297	out:
	298	rcu_read_unlock();
	299
	300	return num;
	301	}
	302
	303	static inline struct net_bridge_fdb_entry fdb_find(struct hlist_head head,
	304	const unsigned char *addr)
	305	{
	306	struct hlist_node *h;
	307	struct net_bridge_fdb_entry *fdb;
	308
	309	hlist_for_each_entry_rcu(fdb, h, head, hlist) {
6ede2463	310	if (!compare_ether_addr(fdb->addr.addr, addr))
1da177e4 LT	311	return fdb;
	312	}
	313	return NULL;
	314	}
	315
	316	static struct net_bridge_fdb_entry fdb_create(struct hlist_head head,
	317	struct net_bridge_port *source,
9d6f229f	318	const unsigned char *addr,
1da177e4 LT	319	int is_local)
	320	{
	321	struct net_bridge_fdb_entry *fdb;
	322
	323	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
	324	if (fdb) {
	325	memcpy(fdb->addr.addr, addr, ETH_ALEN);
	326	atomic_set(&fdb->use_count, 1);
	327	hlist_add_head_rcu(&fdb->hlist, head);
	328
	329	fdb->dst = source;
	330	fdb->is_local = is_local;
	331	fdb->is_static = is_local;
	332	fdb->ageing_timer = jiffies;
	333	}
	334	return fdb;
	335	}
	336
	337	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
	338	const unsigned char *addr)
	339	{
	340	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	341	struct net_bridge_fdb_entry *fdb;
	342
	343	if (!is_valid_ether_addr(addr))
	344	return -EINVAL;
	345
	346	fdb = fdb_find(head, addr);
	347	if (fdb) {
9d6f229f	348	/* it is okay to have multiple ports with same
1da177e4 LT	349	* address, just use the first one.
1da177e4 LT	350	*/
9d6f229f	351	if (fdb->is_local)
1da177e4 LT	352	return 0;
	353
	354	printk(KERN_WARNING "%s adding interface with same address "
	355	"as a received packet\n",
	356	source->dev->name);
	357	fdb_delete(fdb);
9d6f229f	358	}
1da177e4 LT	359
	360	if (!fdb_create(head, source, addr, 1))
	361	return -ENOMEM;
	362
	363	return 0;
	364	}
	365
	366	int br_fdb_insert(struct net_bridge br, struct net_bridge_port source,
	367	const unsigned char *addr)
	368	{
	369	int ret;
	370
	371	spin_lock_bh(&br->hash_lock);
	372	ret = fdb_insert(br, source, addr);
	373	spin_unlock_bh(&br->hash_lock);
	374	return ret;
	375	}
	376
	377	void br_fdb_update(struct net_bridge br, struct net_bridge_port source,
	378	const unsigned char *addr)
	379	{
	380	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	381	struct net_bridge_fdb_entry *fdb;
	382
	383	/* some users want to always flood. */
	384	if (hold_time(br) == 0)
	385	return;
	386
1da177e4 LT	387	fdb = fdb_find(head, addr);
	388	if (likely(fdb)) {
	389	/* attempt to update an entry for a local interface */
	390	if (unlikely(fdb->is_local)) {
9d6f229f	391	if (net_ratelimit())
1da177e4 LT	392	printk(KERN_WARNING "%s: received packet with "
	393	" own address as source address\n",
	394	source->dev->name);
	395	} else {
	396	/* fastpath: update of existing entry */
	397	fdb->dst = source;
	398	fdb->ageing_timer = jiffies;
	399	}
	400	} else {
f8ae737d	401	spin_lock(&br->hash_lock);
1da177e4 LT	402	if (!fdb_find(head, addr))
	403	fdb_create(head, source, addr, 0);
	404	/* else we lose race and someone else inserts
	405	* it first, don't bother updating
	406	*/
f8ae737d	407	spin_unlock(&br->hash_lock);
1da177e4	408	}
1da177e4	409	}