[linux-2.6-block.git] / net / bridge / br_fdb.c

/*
 *	Forwarding database
 *	Linux ethernet bridge
 *
 *	Authors:
 *	Lennert Buytenhek		<buytenh@gnu.org>
 *
 *	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	*
1da177e4 LT	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
	14	#include <linux/kernel.h>
	15	#include <linux/init.h>
82524746	16	#include <linux/rculist.h>
1da177e4 LT	17	#include <linux/spinlock.h>
	18	#include <linux/times.h>
	19	#include <linux/netdevice.h>
	20	#include <linux/etherdevice.h>
	21	#include <linux/jhash.h>
3f890923	22	#include <linux/random.h>
1da177e4	23	#include <asm/atomic.h>
3f890923	24	#include <asm/unaligned.h>
1da177e4 LT	25	#include "br_private.h"
1da177e4 LT	26
e18b890b	27	static struct kmem_cache *br_fdb_cache __read_mostly;
1da177e4 LT	28	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
	29	const unsigned char *addr);
	30
3f890923 SH	31	static u32 fdb_salt __read_mostly;
3f890923 SH	32
87a596e0	33	int __init br_fdb_init(void)
1da177e4 LT	34	{
	35	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
	36	sizeof(struct net_bridge_fdb_entry),
	37	0,
20c2df83	38	SLAB_HWCACHE_ALIGN, NULL);
87a596e0 AM	39	if (!br_fdb_cache)
	40	return -ENOMEM;
	41
3f890923	42	get_random_bytes(&fdb_salt, sizeof(fdb_salt));
87a596e0	43	return 0;
1da177e4 LT	44	}
1da177e4 LT	45
73afc906	46	void br_fdb_fini(void)
1da177e4 LT	47	{
	48	kmem_cache_destroy(br_fdb_cache);
	49	}
	50
	51
	52	/* if topology_changing then use forward_delay (default 15 sec)
	53	* otherwise keep longer (default 5 minutes)
	54	*/
3f890923	55	static inline unsigned long hold_time(const struct net_bridge *br)
1da177e4 LT	56	{
	57	return br->topology_change ? br->forward_delay : br->ageing_time;
	58	}
	59
3f890923	60	static inline int has_expired(const struct net_bridge *br,
1da177e4 LT	61	const struct net_bridge_fdb_entry *fdb)
1da177e4 LT	62	{
9d6f229f	63	return !fdb->is_static
1da177e4 LT	64	&& time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
	65	}
	66
3f890923	67	static inline int br_mac_hash(const unsigned char *mac)
1da177e4	68	{
3f890923 SH	69	/* use 1 byte of OUI cnd 3 bytes of NIC */
	70	u32 key = get_unaligned((u32 *)(mac + 2));
	71	return jhash_1word(key, fdb_salt) & (BR_HASH_SIZE - 1);
1da177e4 LT	72	}
1da177e4 LT	73
3f890923	74	static inline void fdb_delete(struct net_bridge_fdb_entry *f)
1da177e4 LT	75	{
	76	hlist_del_rcu(&f->hlist);
	77	br_fdb_put(f);
	78	}
	79
	80	void br_fdb_changeaddr(struct net_bridge_port p, const unsigned char newaddr)
	81	{
	82	struct net_bridge *br = p->br;
	83	int i;
9d6f229f	84
1da177e4 LT	85	spin_lock_bh(&br->hash_lock);
	86
	87	/* Search all chains since old address/hash is unknown */
	88	for (i = 0; i < BR_HASH_SIZE; i++) {
	89	struct hlist_node *h;
	90	hlist_for_each(h, &br->hash[i]) {
	91	struct net_bridge_fdb_entry *f;
	92
	93	f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
	94	if (f->dst == p && f->is_local) {
	95	/* maybe another port has same hw addr? */
	96	struct net_bridge_port *op;
	97	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	98	if (op != p &&
6ede2463 SH	99	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	100	f->addr.addr)) {
1da177e4 LT	101	f->dst = op;
	102	goto insert;
	103	}
	104	}
	105
	106	/* delete old one */
	107	fdb_delete(f);
	108	goto insert;
	109	}
	110	}
	111	}
	112	insert:
	113	/* insert new address, may fail if invalid address or dup. */
	114	fdb_insert(br, p, newaddr);
	115
	116	spin_unlock_bh(&br->hash_lock);
	117	}
	118
	119	void br_fdb_cleanup(unsigned long _data)
	120	{
	121	struct net_bridge br = (struct net_bridge )_data;
	122	unsigned long delay = hold_time(br);
071f7722	123	unsigned long next_timer = jiffies + br->forward_delay;
1da177e4 LT	124	int i;
	125
	126	spin_lock_bh(&br->hash_lock);
	127	for (i = 0; i < BR_HASH_SIZE; i++) {
	128	struct net_bridge_fdb_entry *f;
	129	struct hlist_node h, n;
	130
	131	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
071f7722 BE	132	unsigned long this_timer;
	133	if (f->is_static)
	134	continue;
	135	this_timer = f->ageing_timer + delay;
	136	if (time_before_eq(this_timer, jiffies))
1da177e4	137	fdb_delete(f);
2bec008c	138	else if (time_before(this_timer, next_timer))
071f7722	139	next_timer = this_timer;
1da177e4 LT	140	}
	141	}
	142	spin_unlock_bh(&br->hash_lock);
	143
071f7722 BE	144	/* Add HZ/4 to ensure we round the jiffies upwards to be after the next
	145	* timer, otherwise we might round down and will have no-op run. */
	146	mod_timer(&br->gc_timer, round_jiffies(next_timer + HZ/4));
1da177e4 LT	147	}
1da177e4 LT	148
9cf63747 SH	149	/* Completely flush all dynamic entries in forwarding database.*/
	150	void br_fdb_flush(struct net_bridge *br)
	151	{
	152	int i;
	153
	154	spin_lock_bh(&br->hash_lock);
	155	for (i = 0; i < BR_HASH_SIZE; i++) {
	156	struct net_bridge_fdb_entry *f;
	157	struct hlist_node h, n;
	158	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
	159	if (!f->is_static)
	160	fdb_delete(f);
	161	}
	162	}
	163	spin_unlock_bh(&br->hash_lock);
	164	}
1a620698	165
9cf63747 SH	166	/* Flush all entries refering to a specific port.
	167	* if do_all is set also flush static entries
	168	*/
1a620698 SH	169	void br_fdb_delete_by_port(struct net_bridge *br,
	170	const struct net_bridge_port *p,
	171	int do_all)
1da177e4 LT	172	{
	173	int i;
	174
	175	spin_lock_bh(&br->hash_lock);
	176	for (i = 0; i < BR_HASH_SIZE; i++) {
	177	struct hlist_node h, g;
9d6f229f	178
1da177e4 LT	179	hlist_for_each_safe(h, g, &br->hash[i]) {
	180	struct net_bridge_fdb_entry *f
	181	= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
9d6f229f	182	if (f->dst != p)
1da177e4 LT	183	continue;
1da177e4 LT	184
1a620698 SH	185	if (f->is_static && !do_all)
1a620698 SH	186	continue;
1da177e4 LT	187	/*
	188	* if multiple ports all have the same device address
	189	* then when one port is deleted, assign
	190	* the local entry to other port
	191	*/
	192	if (f->is_local) {
	193	struct net_bridge_port *op;
	194	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	195	if (op != p &&
6ede2463 SH	196	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	197	f->addr.addr)) {
1da177e4 LT	198	f->dst = op;
	199	goto skip_delete;
	200	}
	201	}
	202	}
	203
	204	fdb_delete(f);
	205	skip_delete: ;
	206	}
	207	}
	208	spin_unlock_bh(&br->hash_lock);
	209	}
	210
	211	/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
	212	struct net_bridge_fdb_entry __br_fdb_get(struct net_bridge br,
	213	const unsigned char *addr)
	214	{
	215	struct hlist_node *h;
	216	struct net_bridge_fdb_entry *fdb;
	217
	218	hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
6ede2463	219	if (!compare_ether_addr(fdb->addr.addr, addr)) {
1da177e4 LT	220	if (unlikely(has_expired(br, fdb)))
	221	break;
	222	return fdb;
	223	}
	224	}
	225
	226	return NULL;
	227	}
	228
	229	/* Interface used by ATM hook that keeps a ref count */
9d6f229f	230	struct net_bridge_fdb_entry br_fdb_get(struct net_bridge br,
1da177e4 LT	231	unsigned char *addr)
	232	{
	233	struct net_bridge_fdb_entry *fdb;
	234
	235	rcu_read_lock();
	236	fdb = __br_fdb_get(br, addr);
b19cbe2a PM	237	if (fdb && !atomic_inc_not_zero(&fdb->use_count))
b19cbe2a PM	238	fdb = NULL;
1da177e4 LT	239	rcu_read_unlock();
	240	return fdb;
	241	}
	242
	243	static void fdb_rcu_free(struct rcu_head *head)
	244	{
	245	struct net_bridge_fdb_entry *ent
	246	= container_of(head, struct net_bridge_fdb_entry, rcu);
	247	kmem_cache_free(br_fdb_cache, ent);
	248	}
	249
	250	/* Set entry up for deletion with RCU */
	251	void br_fdb_put(struct net_bridge_fdb_entry *ent)
	252	{
	253	if (atomic_dec_and_test(&ent->use_count))
	254	call_rcu(&ent->rcu, fdb_rcu_free);
	255	}
	256
	257	/*
9d6f229f	258	* Fill buffer with forwarding table records in
1da177e4 LT	259	* the API format.
	260	*/
	261	int br_fdb_fillbuf(struct net_bridge br, void buf,
	262	unsigned long maxnum, unsigned long skip)
	263	{
	264	struct __fdb_entry *fe = buf;
	265	int i, num = 0;
	266	struct hlist_node *h;
	267	struct net_bridge_fdb_entry *f;
	268
	269	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
	270
	271	rcu_read_lock();
	272	for (i = 0; i < BR_HASH_SIZE; i++) {
	273	hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
	274	if (num >= maxnum)
	275	goto out;
	276
9d6f229f	277	if (has_expired(br, f))
1da177e4 LT	278	continue;
	279
	280	if (skip) {
	281	--skip;
	282	continue;
	283	}
	284
	285	/* convert from internal format to API */
	286	memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
ae4f8fca SH	287
ae4f8fca SH	288	/* due to ABI compat need to split into hi/lo */
1da177e4	289	fe->port_no = f->dst->port_no;
ae4f8fca SH	290	fe->port_hi = f->dst->port_no >> 8;
ae4f8fca SH	291
1da177e4 LT	292	fe->is_local = f->is_local;
	293	if (!f->is_static)
	294	fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer);
	295	++fe;
	296	++num;
	297	}
	298	}
	299
	300	out:
	301	rcu_read_unlock();
	302
	303	return num;
	304	}
	305
	306	static inline struct net_bridge_fdb_entry fdb_find(struct hlist_head head,
	307	const unsigned char *addr)
	308	{
	309	struct hlist_node *h;
	310	struct net_bridge_fdb_entry *fdb;
	311
	312	hlist_for_each_entry_rcu(fdb, h, head, hlist) {
6ede2463	313	if (!compare_ether_addr(fdb->addr.addr, addr))
1da177e4 LT	314	return fdb;
	315	}
	316	return NULL;
	317	}
	318
	319	static struct net_bridge_fdb_entry fdb_create(struct hlist_head head,
	320	struct net_bridge_port *source,
9d6f229f	321	const unsigned char *addr,
1da177e4 LT	322	int is_local)
	323	{
	324	struct net_bridge_fdb_entry *fdb;
	325
	326	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
	327	if (fdb) {
	328	memcpy(fdb->addr.addr, addr, ETH_ALEN);
	329	atomic_set(&fdb->use_count, 1);
	330	hlist_add_head_rcu(&fdb->hlist, head);
	331
	332	fdb->dst = source;
	333	fdb->is_local = is_local;
	334	fdb->is_static = is_local;
	335	fdb->ageing_timer = jiffies;
	336	}
	337	return fdb;
	338	}
	339
	340	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
	341	const unsigned char *addr)
	342	{
	343	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	344	struct net_bridge_fdb_entry *fdb;
	345
	346	if (!is_valid_ether_addr(addr))
	347	return -EINVAL;
	348
	349	fdb = fdb_find(head, addr);
	350	if (fdb) {
9d6f229f	351	/* it is okay to have multiple ports with same
1da177e4 LT	352	* address, just use the first one.
1da177e4 LT	353	*/
9d6f229f	354	if (fdb->is_local)
1da177e4 LT	355	return 0;
	356
	357	printk(KERN_WARNING "%s adding interface with same address "
	358	"as a received packet\n",
	359	source->dev->name);
	360	fdb_delete(fdb);
9d6f229f	361	}
1da177e4 LT	362
	363	if (!fdb_create(head, source, addr, 1))
	364	return -ENOMEM;
	365
	366	return 0;
	367	}
	368
	369	int br_fdb_insert(struct net_bridge br, struct net_bridge_port source,
	370	const unsigned char *addr)
	371	{
	372	int ret;
	373
	374	spin_lock_bh(&br->hash_lock);
	375	ret = fdb_insert(br, source, addr);
	376	spin_unlock_bh(&br->hash_lock);
	377	return ret;
	378	}
	379
	380	void br_fdb_update(struct net_bridge br, struct net_bridge_port source,
	381	const unsigned char *addr)
	382	{
	383	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	384	struct net_bridge_fdb_entry *fdb;
	385
	386	/* some users want to always flood. */
	387	if (hold_time(br) == 0)
	388	return;
	389
df1c0b84 SH	390	/* ignore packets unless we are using this port */
	391	if (!(source->state == BR_STATE_LEARNING \|\|
	392	source->state == BR_STATE_FORWARDING))
	393	return;
	394
1da177e4 LT	395	fdb = fdb_find(head, addr);
	396	if (likely(fdb)) {
	397	/* attempt to update an entry for a local interface */
	398	if (unlikely(fdb->is_local)) {
9d6f229f	399	if (net_ratelimit())
1da177e4 LT	400	printk(KERN_WARNING "%s: received packet with "
	401	" own address as source address\n",
	402	source->dev->name);
	403	} else {
	404	/* fastpath: update of existing entry */
	405	fdb->dst = source;
	406	fdb->ageing_timer = jiffies;
	407	}
	408	} else {
f8ae737d	409	spin_lock(&br->hash_lock);
1da177e4 LT	410	if (!fdb_find(head, addr))
	411	fdb_create(head, source, addr, 0);
	412	/* else we lose race and someone else inserts
	413	* it first, don't bother updating
	414	*/
f8ae737d	415	spin_unlock(&br->hash_lock);
1da177e4	416	}
1da177e4	417	}