[linux.git] / net / bridge / br_fdb.c

/*
 *	Forwarding database
 *	Linux ethernet bridge
 *
 *	Authors:
 *	Lennert Buytenhek		<[email protected]>
 *
 *	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 <linux/slab.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 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);
}

static inline void fdb_delete(struct net_bridge_fdb_entry *f)
{
	hlist_del_rcu(&f->hlist);
	call_rcu(&f->rcu, fdb_rcu_free);
}

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->ageing_time;
	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);

	mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
}

/* 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;
}

#if defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE)
/* Interface used by ATM LANE hook to test
 * if an addr is on some other bridge port */
int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
{
	struct net_bridge_fdb_entry *fdb;
	int ret;

	if (!dev->br_port)
		return 0;

	rcu_read_lock();
	fdb = __br_fdb_get(dev->br_port->br, addr);
	ret = fdb && fdb->dst->dev != dev &&
		fdb->dst->state == BR_STATE_FORWARDING;
	rcu_read_unlock();

	return ret;
}
#endif /* CONFIG_ATM_LANE */

/*
 * 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);
		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;
		br_warn(br, "adding interface %s 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())
				br_warn(br, "received packet on %s 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 <[email protected]>
	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>
5a0e3ad6	23	#include <linux/slab.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	}
1da177e4 LT	46
73afc906	47	void br_fdb_fini(void)
1da177e4 LT	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	{
f64f9e71 JP	64	return !fdb->is_static &&
f64f9e71 JP	65	time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
1da177e4 LT	66	}
1da177e4 LT	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
da678292 MM	75	static void fdb_rcu_free(struct rcu_head *head)
	76	{
	77	struct net_bridge_fdb_entry *ent
	78	= container_of(head, struct net_bridge_fdb_entry, rcu);
	79	kmem_cache_free(br_fdb_cache, ent);
	80	}
	81
3f890923	82	static inline void fdb_delete(struct net_bridge_fdb_entry *f)
1da177e4 LT	83	{
1da177e4 LT	84	hlist_del_rcu(&f->hlist);
da678292	85	call_rcu(&f->rcu, fdb_rcu_free);
1da177e4 LT	86	}
	87
	88	void br_fdb_changeaddr(struct net_bridge_port p, const unsigned char newaddr)
	89	{
	90	struct net_bridge *br = p->br;
	91	int i;
9d6f229f	92
1da177e4 LT	93	spin_lock_bh(&br->hash_lock);
	94
	95	/* Search all chains since old address/hash is unknown */
	96	for (i = 0; i < BR_HASH_SIZE; i++) {
	97	struct hlist_node *h;
	98	hlist_for_each(h, &br->hash[i]) {
	99	struct net_bridge_fdb_entry *f;
	100
	101	f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
	102	if (f->dst == p && f->is_local) {
	103	/* maybe another port has same hw addr? */
	104	struct net_bridge_port *op;
	105	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	106	if (op != p &&
6ede2463 SH	107	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	108	f->addr.addr)) {
1da177e4 LT	109	f->dst = op;
	110	goto insert;
	111	}
	112	}
	113
	114	/* delete old one */
	115	fdb_delete(f);
	116	goto insert;
	117	}
	118	}
	119	}
	120	insert:
	121	/* insert new address, may fail if invalid address or dup. */
	122	fdb_insert(br, p, newaddr);
	123
	124	spin_unlock_bh(&br->hash_lock);
	125	}
	126
	127	void br_fdb_cleanup(unsigned long _data)
	128	{
	129	struct net_bridge br = (struct net_bridge )_data;
	130	unsigned long delay = hold_time(br);
25442e06	131	unsigned long next_timer = jiffies + br->ageing_time;
1da177e4 LT	132	int i;
	133
	134	spin_lock_bh(&br->hash_lock);
	135	for (i = 0; i < BR_HASH_SIZE; i++) {
	136	struct net_bridge_fdb_entry *f;
	137	struct hlist_node h, n;
	138
	139	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
071f7722 BE	140	unsigned long this_timer;
	141	if (f->is_static)
	142	continue;
	143	this_timer = f->ageing_timer + delay;
	144	if (time_before_eq(this_timer, jiffies))
1da177e4	145	fdb_delete(f);
2bec008c	146	else if (time_before(this_timer, next_timer))
071f7722	147	next_timer = this_timer;
1da177e4 LT	148	}
	149	}
	150	spin_unlock_bh(&br->hash_lock);
	151
25442e06	152	mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
1da177e4 LT	153	}
1da177e4 LT	154
9cf63747 SH	155	/* Completely flush all dynamic entries in forwarding database.*/
	156	void br_fdb_flush(struct net_bridge *br)
	157	{
	158	int i;
	159
	160	spin_lock_bh(&br->hash_lock);
	161	for (i = 0; i < BR_HASH_SIZE; i++) {
	162	struct net_bridge_fdb_entry *f;
	163	struct hlist_node h, n;
	164	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
	165	if (!f->is_static)
	166	fdb_delete(f);
	167	}
	168	}
	169	spin_unlock_bh(&br->hash_lock);
	170	}
1a620698	171
9cf63747 SH	172	/* Flush all entries refering to a specific port.
	173	* if do_all is set also flush static entries
	174	*/
1a620698 SH	175	void br_fdb_delete_by_port(struct net_bridge *br,
	176	const struct net_bridge_port *p,
	177	int do_all)
1da177e4 LT	178	{
	179	int i;
	180
	181	spin_lock_bh(&br->hash_lock);
	182	for (i = 0; i < BR_HASH_SIZE; i++) {
	183	struct hlist_node h, g;
9d6f229f	184
1da177e4 LT	185	hlist_for_each_safe(h, g, &br->hash[i]) {
	186	struct net_bridge_fdb_entry *f
	187	= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
9d6f229f	188	if (f->dst != p)
1da177e4 LT	189	continue;
1da177e4 LT	190
1a620698 SH	191	if (f->is_static && !do_all)
1a620698 SH	192	continue;
1da177e4 LT	193	/*
	194	* if multiple ports all have the same device address
	195	* then when one port is deleted, assign
	196	* the local entry to other port
	197	*/
	198	if (f->is_local) {
	199	struct net_bridge_port *op;
	200	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	201	if (op != p &&
6ede2463 SH	202	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	203	f->addr.addr)) {
1da177e4 LT	204	f->dst = op;
	205	goto skip_delete;
	206	}
	207	}
	208	}
	209
	210	fdb_delete(f);
	211	skip_delete: ;
	212	}
	213	}
	214	spin_unlock_bh(&br->hash_lock);
	215	}
	216
	217	/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
	218	struct net_bridge_fdb_entry __br_fdb_get(struct net_bridge br,
	219	const unsigned char *addr)
	220	{
	221	struct hlist_node *h;
	222	struct net_bridge_fdb_entry *fdb;
	223
	224	hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
6ede2463	225	if (!compare_ether_addr(fdb->addr.addr, addr)) {
1da177e4 LT	226	if (unlikely(has_expired(br, fdb)))
	227	break;
	228	return fdb;
	229	}
	230	}
	231
	232	return NULL;
	233	}
	234
da678292 MM	235	#if defined(CONFIG_ATM_LANE) \|\| defined(CONFIG_ATM_LANE_MODULE)
	236	/* Interface used by ATM LANE hook to test
	237	* if an addr is on some other bridge port */
	238	int br_fdb_test_addr(struct net_device dev, unsigned char addr)
1da177e4 LT	239	{
1da177e4 LT	240	struct net_bridge_fdb_entry *fdb;
da678292 MM	241	int ret;
	242
	243	if (!dev->br_port)
	244	return 0;
1da177e4 LT	245
1da177e4 LT	246	rcu_read_lock();
da678292 MM	247	fdb = __br_fdb_get(dev->br_port->br, addr);
	248	ret = fdb && fdb->dst->dev != dev &&
	249	fdb->dst->state == BR_STATE_FORWARDING;
1da177e4	250	rcu_read_unlock();
1da177e4	251
da678292	252	return ret;
1da177e4	253	}
da678292	254	#endif /* CONFIG_ATM_LANE */
1da177e4 LT	255
1da177e4 LT	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);
1da177e4 LT	328	hlist_add_head_rcu(&fdb->hlist, head);
	329
	330	fdb->dst = source;
	331	fdb->is_local = is_local;
	332	fdb->is_static = is_local;
	333	fdb->ageing_timer = jiffies;
	334	}
	335	return fdb;
	336	}
	337
	338	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
	339	const unsigned char *addr)
	340	{
	341	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	342	struct net_bridge_fdb_entry *fdb;
	343
	344	if (!is_valid_ether_addr(addr))
	345	return -EINVAL;
	346
	347	fdb = fdb_find(head, addr);
	348	if (fdb) {
9d6f229f	349	/* it is okay to have multiple ports with same
1da177e4 LT	350	* address, just use the first one.
1da177e4 LT	351	*/
9d6f229f	352	if (fdb->is_local)
1da177e4	353	return 0;
28a16c97	354	br_warn(br, "adding interface %s with same address "
1da177e4 LT	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
df1c0b84 SH	387	/* ignore packets unless we are using this port */
	388	if (!(source->state == BR_STATE_LEARNING \|\|
	389	source->state == BR_STATE_FORWARDING))
	390	return;
	391
1da177e4 LT	392	fdb = fdb_find(head, addr);
	393	if (likely(fdb)) {
	394	/* attempt to update an entry for a local interface */
	395	if (unlikely(fdb->is_local)) {
9d6f229f	396	if (net_ratelimit())
28a16c97	397	br_warn(br, "received packet on %s with "
	398	"own address as source address\n",
	399	source->dev->name);
1da177e4 LT	400	} else {
	401	/* fastpath: update of existing entry */
	402	fdb->dst = source;
	403	fdb->ageing_timer = jiffies;
	404	}
	405	} else {
f8ae737d	406	spin_lock(&br->hash_lock);
1da177e4 LT	407	if (!fdb_find(head, addr))
	408	fdb_create(head, source, addr, 0);
	409	/* else we lose race and someone else inserts
	410	* it first, don't bother updating
	411	*/
f8ae737d	412	spin_unlock(&br->hash_lock);
1da177e4	413	}
1da177e4	414	}