[GitHub/mt8127/android_kernel_alcatel_ttab.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/rculist.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 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 (time_before(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);

			/* due to ABI compat need to split into hi/lo */
			fe->port_no = f->dst->port_no;
			fe->port_hi = f->dst->port_no >> 8;

			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;

	/* ignore packets unless we are using this port */
	if (!(source->state == BR_STATE_LEARNING ||
	      source->state == BR_STATE_FORWARDING))
		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>
82524746	18	#include <linux/rculist.h>
1da177e4 LT	19	#include <linux/spinlock.h>
	20	#include <linux/times.h>
	21	#include <linux/netdevice.h>
	22	#include <linux/etherdevice.h>
	23	#include <linux/jhash.h>
3f890923	24	#include <linux/random.h>
1da177e4	25	#include <asm/atomic.h>
3f890923	26	#include <asm/unaligned.h>
1da177e4 LT	27	#include "br_private.h"
1da177e4 LT	28
e18b890b	29	static struct kmem_cache *br_fdb_cache __read_mostly;
1da177e4 LT	30	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
	31	const unsigned char *addr);
	32
3f890923 SH	33	static u32 fdb_salt __read_mostly;
3f890923 SH	34
87a596e0	35	int __init br_fdb_init(void)
1da177e4 LT	36	{
	37	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
	38	sizeof(struct net_bridge_fdb_entry),
	39	0,
20c2df83	40	SLAB_HWCACHE_ALIGN, NULL);
87a596e0 AM	41	if (!br_fdb_cache)
	42	return -ENOMEM;
	43
3f890923	44	get_random_bytes(&fdb_salt, sizeof(fdb_salt));
87a596e0	45	return 0;
1da177e4 LT	46	}
1da177e4 LT	47
73afc906	48	void br_fdb_fini(void)
1da177e4 LT	49	{
	50	kmem_cache_destroy(br_fdb_cache);
	51	}
	52
	53
	54	/* if topology_changing then use forward_delay (default 15 sec)
	55	* otherwise keep longer (default 5 minutes)
	56	*/
3f890923	57	static inline unsigned long hold_time(const struct net_bridge *br)
1da177e4 LT	58	{
	59	return br->topology_change ? br->forward_delay : br->ageing_time;
	60	}
	61
3f890923	62	static inline int has_expired(const struct net_bridge *br,
1da177e4 LT	63	const struct net_bridge_fdb_entry *fdb)
1da177e4 LT	64	{
9d6f229f	65	return !fdb->is_static
1da177e4 LT	66	&& time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
	67	}
	68
3f890923	69	static inline int br_mac_hash(const unsigned char *mac)
1da177e4	70	{
3f890923 SH	71	/* use 1 byte of OUI cnd 3 bytes of NIC */
	72	u32 key = get_unaligned((u32 *)(mac + 2));
	73	return jhash_1word(key, fdb_salt) & (BR_HASH_SIZE - 1);
1da177e4 LT	74	}
1da177e4 LT	75
3f890923	76	static inline void fdb_delete(struct net_bridge_fdb_entry *f)
1da177e4 LT	77	{
	78	hlist_del_rcu(&f->hlist);
	79	br_fdb_put(f);
	80	}
	81
	82	void br_fdb_changeaddr(struct net_bridge_port p, const unsigned char newaddr)
	83	{
	84	struct net_bridge *br = p->br;
	85	int i;
9d6f229f	86
1da177e4 LT	87	spin_lock_bh(&br->hash_lock);
	88
	89	/* Search all chains since old address/hash is unknown */
	90	for (i = 0; i < BR_HASH_SIZE; i++) {
	91	struct hlist_node *h;
	92	hlist_for_each(h, &br->hash[i]) {
	93	struct net_bridge_fdb_entry *f;
	94
	95	f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
	96	if (f->dst == p && f->is_local) {
	97	/* maybe another port has same hw addr? */
	98	struct net_bridge_port *op;
	99	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	100	if (op != p &&
6ede2463 SH	101	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	102	f->addr.addr)) {
1da177e4 LT	103	f->dst = op;
	104	goto insert;
	105	}
	106	}
	107
	108	/* delete old one */
	109	fdb_delete(f);
	110	goto insert;
	111	}
	112	}
	113	}
	114	insert:
	115	/* insert new address, may fail if invalid address or dup. */
	116	fdb_insert(br, p, newaddr);
	117
	118	spin_unlock_bh(&br->hash_lock);
	119	}
	120
	121	void br_fdb_cleanup(unsigned long _data)
	122	{
	123	struct net_bridge br = (struct net_bridge )_data;
	124	unsigned long delay = hold_time(br);
071f7722	125	unsigned long next_timer = jiffies + br->forward_delay;
1da177e4 LT	126	int i;
	127
	128	spin_lock_bh(&br->hash_lock);
	129	for (i = 0; i < BR_HASH_SIZE; i++) {
	130	struct net_bridge_fdb_entry *f;
	131	struct hlist_node h, n;
	132
	133	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
071f7722 BE	134	unsigned long this_timer;
	135	if (f->is_static)
	136	continue;
	137	this_timer = f->ageing_timer + delay;
	138	if (time_before_eq(this_timer, jiffies))
1da177e4	139	fdb_delete(f);
2bec008c	140	else if (time_before(this_timer, next_timer))
071f7722	141	next_timer = this_timer;
1da177e4 LT	142	}
	143	}
	144	spin_unlock_bh(&br->hash_lock);
	145
071f7722 BE	146	/* Add HZ/4 to ensure we round the jiffies upwards to be after the next
	147	* timer, otherwise we might round down and will have no-op run. */
	148	mod_timer(&br->gc_timer, round_jiffies(next_timer + HZ/4));
1da177e4 LT	149	}
1da177e4 LT	150
9cf63747 SH	151	/* Completely flush all dynamic entries in forwarding database.*/
	152	void br_fdb_flush(struct net_bridge *br)
	153	{
	154	int i;
	155
	156	spin_lock_bh(&br->hash_lock);
	157	for (i = 0; i < BR_HASH_SIZE; i++) {
	158	struct net_bridge_fdb_entry *f;
	159	struct hlist_node h, n;
	160	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
	161	if (!f->is_static)
	162	fdb_delete(f);
	163	}
	164	}
	165	spin_unlock_bh(&br->hash_lock);
	166	}
1a620698	167
9cf63747 SH	168	/* Flush all entries refering to a specific port.
	169	* if do_all is set also flush static entries
	170	*/
1a620698 SH	171	void br_fdb_delete_by_port(struct net_bridge *br,
	172	const struct net_bridge_port *p,
	173	int do_all)
1da177e4 LT	174	{
	175	int i;
	176
	177	spin_lock_bh(&br->hash_lock);
	178	for (i = 0; i < BR_HASH_SIZE; i++) {
	179	struct hlist_node h, g;
9d6f229f	180
1da177e4 LT	181	hlist_for_each_safe(h, g, &br->hash[i]) {
	182	struct net_bridge_fdb_entry *f
	183	= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
9d6f229f	184	if (f->dst != p)
1da177e4 LT	185	continue;
1da177e4 LT	186
1a620698 SH	187	if (f->is_static && !do_all)
1a620698 SH	188	continue;
1da177e4 LT	189	/*
	190	* if multiple ports all have the same device address
	191	* then when one port is deleted, assign
	192	* the local entry to other port
	193	*/
	194	if (f->is_local) {
	195	struct net_bridge_port *op;
	196	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	197	if (op != p &&
6ede2463 SH	198	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	199	f->addr.addr)) {
1da177e4 LT	200	f->dst = op;
	201	goto skip_delete;
	202	}
	203	}
	204	}
	205
	206	fdb_delete(f);
	207	skip_delete: ;
	208	}
	209	}
	210	spin_unlock_bh(&br->hash_lock);
	211	}
	212
	213	/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
	214	struct net_bridge_fdb_entry __br_fdb_get(struct net_bridge br,
	215	const unsigned char *addr)
	216	{
	217	struct hlist_node *h;
	218	struct net_bridge_fdb_entry *fdb;
	219
	220	hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
6ede2463	221	if (!compare_ether_addr(fdb->addr.addr, addr)) {
1da177e4 LT	222	if (unlikely(has_expired(br, fdb)))
	223	break;
	224	return fdb;
	225	}
	226	}
	227
	228	return NULL;
	229	}
	230
	231	/* Interface used by ATM hook that keeps a ref count */
9d6f229f	232	struct net_bridge_fdb_entry br_fdb_get(struct net_bridge br,
1da177e4 LT	233	unsigned char *addr)
	234	{
	235	struct net_bridge_fdb_entry *fdb;
	236
	237	rcu_read_lock();
	238	fdb = __br_fdb_get(br, addr);
b19cbe2a PM	239	if (fdb && !atomic_inc_not_zero(&fdb->use_count))
b19cbe2a PM	240	fdb = NULL;
1da177e4 LT	241	rcu_read_unlock();
	242	return fdb;
	243	}
	244
	245	static void fdb_rcu_free(struct rcu_head *head)
	246	{
	247	struct net_bridge_fdb_entry *ent
	248	= container_of(head, struct net_bridge_fdb_entry, rcu);
	249	kmem_cache_free(br_fdb_cache, ent);
	250	}
	251
	252	/* Set entry up for deletion with RCU */
	253	void br_fdb_put(struct net_bridge_fdb_entry *ent)
	254	{
	255	if (atomic_dec_and_test(&ent->use_count))
	256	call_rcu(&ent->rcu, fdb_rcu_free);
	257	}
	258
	259	/*
9d6f229f	260	* Fill buffer with forwarding table records in
1da177e4 LT	261	* the API format.
	262	*/
	263	int br_fdb_fillbuf(struct net_bridge br, void buf,
	264	unsigned long maxnum, unsigned long skip)
	265	{
	266	struct __fdb_entry *fe = buf;
	267	int i, num = 0;
	268	struct hlist_node *h;
	269	struct net_bridge_fdb_entry *f;
	270
	271	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
	272
	273	rcu_read_lock();
	274	for (i = 0; i < BR_HASH_SIZE; i++) {
	275	hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
	276	if (num >= maxnum)
	277	goto out;
	278
9d6f229f	279	if (has_expired(br, f))
1da177e4 LT	280	continue;
	281
	282	if (skip) {
	283	--skip;
	284	continue;
	285	}
	286
	287	/* convert from internal format to API */
	288	memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
ae4f8fca SH	289
ae4f8fca SH	290	/* due to ABI compat need to split into hi/lo */
1da177e4	291	fe->port_no = f->dst->port_no;
ae4f8fca SH	292	fe->port_hi = f->dst->port_no >> 8;
ae4f8fca SH	293
1da177e4 LT	294	fe->is_local = f->is_local;
	295	if (!f->is_static)
	296	fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer);
	297	++fe;
	298	++num;
	299	}
	300	}
	301
	302	out:
	303	rcu_read_unlock();
	304
	305	return num;
	306	}
	307
	308	static inline struct net_bridge_fdb_entry fdb_find(struct hlist_head head,
	309	const unsigned char *addr)
	310	{
	311	struct hlist_node *h;
	312	struct net_bridge_fdb_entry *fdb;
	313
	314	hlist_for_each_entry_rcu(fdb, h, head, hlist) {
6ede2463	315	if (!compare_ether_addr(fdb->addr.addr, addr))
1da177e4 LT	316	return fdb;
	317	}
	318	return NULL;
	319	}
	320
	321	static struct net_bridge_fdb_entry fdb_create(struct hlist_head head,
	322	struct net_bridge_port *source,
9d6f229f	323	const unsigned char *addr,
1da177e4 LT	324	int is_local)
	325	{
	326	struct net_bridge_fdb_entry *fdb;
	327
	328	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
	329	if (fdb) {
	330	memcpy(fdb->addr.addr, addr, ETH_ALEN);
	331	atomic_set(&fdb->use_count, 1);
	332	hlist_add_head_rcu(&fdb->hlist, head);
	333
	334	fdb->dst = source;
	335	fdb->is_local = is_local;
	336	fdb->is_static = is_local;
	337	fdb->ageing_timer = jiffies;
	338	}
	339	return fdb;
	340	}
	341
	342	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
	343	const unsigned char *addr)
	344	{
	345	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	346	struct net_bridge_fdb_entry *fdb;
	347
	348	if (!is_valid_ether_addr(addr))
	349	return -EINVAL;
	350
	351	fdb = fdb_find(head, addr);
	352	if (fdb) {
9d6f229f	353	/* it is okay to have multiple ports with same
1da177e4 LT	354	* address, just use the first one.
1da177e4 LT	355	*/
9d6f229f	356	if (fdb->is_local)
1da177e4 LT	357	return 0;
	358
	359	printk(KERN_WARNING "%s adding interface with same address "
	360	"as a received packet\n",
	361	source->dev->name);
	362	fdb_delete(fdb);
9d6f229f	363	}
1da177e4 LT	364
	365	if (!fdb_create(head, source, addr, 1))
	366	return -ENOMEM;
	367
	368	return 0;
	369	}
	370
	371	int br_fdb_insert(struct net_bridge br, struct net_bridge_port source,
	372	const unsigned char *addr)
	373	{
	374	int ret;
	375
	376	spin_lock_bh(&br->hash_lock);
	377	ret = fdb_insert(br, source, addr);
	378	spin_unlock_bh(&br->hash_lock);
	379	return ret;
	380	}
	381
	382	void br_fdb_update(struct net_bridge br, struct net_bridge_port source,
	383	const unsigned char *addr)
	384	{
	385	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	386	struct net_bridge_fdb_entry *fdb;
	387
	388	/* some users want to always flood. */
	389	if (hold_time(br) == 0)
	390	return;
	391
df1c0b84 SH	392	/* ignore packets unless we are using this port */
	393	if (!(source->state == BR_STATE_LEARNING \|\|
	394	source->state == BR_STATE_FORWARDING))
	395	return;
	396
1da177e4 LT	397	fdb = fdb_find(head, addr);
	398	if (likely(fdb)) {
	399	/* attempt to update an entry for a local interface */
	400	if (unlikely(fdb->is_local)) {
9d6f229f	401	if (net_ratelimit())
1da177e4 LT	402	printk(KERN_WARNING "%s: received packet with "
	403	" own address as source address\n",
	404	source->dev->name);
	405	} else {
	406	/* fastpath: update of existing entry */
	407	fdb->dst = source;
	408	fdb->ageing_timer = jiffies;
	409	}
	410	} else {
f8ae737d	411	spin_lock(&br->hash_lock);
1da177e4 LT	412	if (!fdb_find(head, addr))
	413	fdb_create(head, source, addr, 0);
	414	/* else we lose race and someone else inserts
	415	* it first, don't bother updating
	416	*/
f8ae737d	417	spin_unlock(&br->hash_lock);
1da177e4	418	}
1da177e4	419	}