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