[linux-2.6-block.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 <asm/atomic.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);

void __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, NULL);
}

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)
{
	return jhash(mac, ETH_ALEN, 0) & (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);
	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 && 
			    time_before_eq(f->ageing_timer + delay, jiffies)) 
				fdb_delete(f);
		}
	}
	spin_unlock_bh(&br->hash_lock);

	mod_timer(&br->gc_timer, jiffies + HZ/10);
}


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(&fdb->use_count);
	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>
	23	#include <asm/atomic.h>
	24	#include "br_private.h"
	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
	30	void __init br_fdb_init(void)
	31	{
	32	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
	33	sizeof(struct net_bridge_fdb_entry),
	34	0,
	35	SLAB_HWCACHE_ALIGN, NULL, NULL);
	36	}
	37
	38	void __exit br_fdb_fini(void)
	39	{
	40	kmem_cache_destroy(br_fdb_cache);
	41	}
	42
	43
	44	/* if topology_changing then use forward_delay (default 15 sec)
	45	* otherwise keep longer (default 5 minutes)
	46	*/
	47	static __inline__ unsigned long hold_time(const struct net_bridge *br)
	48	{
	49	return br->topology_change ? br->forward_delay : br->ageing_time;
	50	}
	51
	52	static __inline__ int has_expired(const struct net_bridge *br,
	53	const struct net_bridge_fdb_entry *fdb)
	54	{
	55	return !fdb->is_static
	56	&& time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
	57	}
	58
	59	static __inline__ int br_mac_hash(const unsigned char *mac)
	60	{
	61	return jhash(mac, ETH_ALEN, 0) & (BR_HASH_SIZE - 1);
	62	}
	63
	64	static __inline__ void fdb_delete(struct net_bridge_fdb_entry *f)
	65	{
	66	hlist_del_rcu(&f->hlist);
	67	br_fdb_put(f);
	68	}
	69
	70	void br_fdb_changeaddr(struct net_bridge_port p, const unsigned char newaddr)
	71	{
	72	struct net_bridge *br = p->br;
	73	int i;
	74
	75	spin_lock_bh(&br->hash_lock);
	76
	77	/* Search all chains since old address/hash is unknown */
	78	for (i = 0; i < BR_HASH_SIZE; i++) {
	79	struct hlist_node *h;
	80	hlist_for_each(h, &br->hash[i]) {
	81	struct net_bridge_fdb_entry *f;
	82
	83	f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
	84	if (f->dst == p && f->is_local) {
	85	/* maybe another port has same hw addr? */
	86	struct net_bridge_port *op;
	87	list_for_each_entry(op, &br->port_list, list) {
	88	if (op != p &&
6ede2463 SH	89	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	90	f->addr.addr)) {
1da177e4 LT	91	f->dst = op;
	92	goto insert;
	93	}
	94	}
	95
	96	/* delete old one */
	97	fdb_delete(f);
	98	goto insert;
	99	}
	100	}
	101	}
	102	insert:
	103	/* insert new address, may fail if invalid address or dup. */
	104	fdb_insert(br, p, newaddr);
	105
	106	spin_unlock_bh(&br->hash_lock);
	107	}
	108
	109	void br_fdb_cleanup(unsigned long _data)
	110	{
	111	struct net_bridge br = (struct net_bridge )_data;
	112	unsigned long delay = hold_time(br);
	113	int i;
	114
	115	spin_lock_bh(&br->hash_lock);
	116	for (i = 0; i < BR_HASH_SIZE; i++) {
	117	struct net_bridge_fdb_entry *f;
	118	struct hlist_node h, n;
	119
	120	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
	121	if (!f->is_static &&
	122	time_before_eq(f->ageing_timer + delay, jiffies))
	123	fdb_delete(f);
	124	}
	125	}
	126	spin_unlock_bh(&br->hash_lock);
	127
	128	mod_timer(&br->gc_timer, jiffies + HZ/10);
	129	}
	130
1a620698 SH	131
	132	void br_fdb_delete_by_port(struct net_bridge *br,
	133	const struct net_bridge_port *p,
	134	int do_all)
1da177e4 LT	135	{
	136	int i;
	137
	138	spin_lock_bh(&br->hash_lock);
	139	for (i = 0; i < BR_HASH_SIZE; i++) {
	140	struct hlist_node h, g;
	141
	142	hlist_for_each_safe(h, g, &br->hash[i]) {
	143	struct net_bridge_fdb_entry *f
	144	= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
	145	if (f->dst != p)
	146	continue;
	147
1a620698 SH	148	if (f->is_static && !do_all)
1a620698 SH	149	continue;
1da177e4 LT	150	/*
	151	* if multiple ports all have the same device address
	152	* then when one port is deleted, assign
	153	* the local entry to other port
	154	*/
	155	if (f->is_local) {
	156	struct net_bridge_port *op;
	157	list_for_each_entry(op, &br->port_list, list) {
	158	if (op != p &&
6ede2463 SH	159	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	160	f->addr.addr)) {
1da177e4 LT	161	f->dst = op;
	162	goto skip_delete;
	163	}
	164	}
	165	}
	166
	167	fdb_delete(f);
	168	skip_delete: ;
	169	}
	170	}
	171	spin_unlock_bh(&br->hash_lock);
	172	}
	173
	174	/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
	175	struct net_bridge_fdb_entry __br_fdb_get(struct net_bridge br,
	176	const unsigned char *addr)
	177	{
	178	struct hlist_node *h;
	179	struct net_bridge_fdb_entry *fdb;
	180
	181	hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
6ede2463	182	if (!compare_ether_addr(fdb->addr.addr, addr)) {
1da177e4 LT	183	if (unlikely(has_expired(br, fdb)))
	184	break;
	185	return fdb;
	186	}
	187	}
	188
	189	return NULL;
	190	}
	191
	192	/* Interface used by ATM hook that keeps a ref count */
	193	struct net_bridge_fdb_entry br_fdb_get(struct net_bridge br,
	194	unsigned char *addr)
	195	{
	196	struct net_bridge_fdb_entry *fdb;
	197
	198	rcu_read_lock();
	199	fdb = __br_fdb_get(br, addr);
	200	if (fdb)
	201	atomic_inc(&fdb->use_count);
	202	rcu_read_unlock();
	203	return fdb;
	204	}
	205
	206	static void fdb_rcu_free(struct rcu_head *head)
	207	{
	208	struct net_bridge_fdb_entry *ent
	209	= container_of(head, struct net_bridge_fdb_entry, rcu);
	210	kmem_cache_free(br_fdb_cache, ent);
	211	}
	212
	213	/* Set entry up for deletion with RCU */
	214	void br_fdb_put(struct net_bridge_fdb_entry *ent)
	215	{
	216	if (atomic_dec_and_test(&ent->use_count))
	217	call_rcu(&ent->rcu, fdb_rcu_free);
	218	}
	219
	220	/*
	221	* Fill buffer with forwarding table records in
	222	* the API format.
	223	*/
	224	int br_fdb_fillbuf(struct net_bridge br, void buf,
	225	unsigned long maxnum, unsigned long skip)
	226	{
	227	struct __fdb_entry *fe = buf;
	228	int i, num = 0;
	229	struct hlist_node *h;
	230	struct net_bridge_fdb_entry *f;
	231
	232	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
	233
	234	rcu_read_lock();
	235	for (i = 0; i < BR_HASH_SIZE; i++) {
	236	hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
	237	if (num >= maxnum)
	238	goto out;
	239
	240	if (has_expired(br, f))
	241	continue;
	242
	243	if (skip) {
	244	--skip;
	245	continue;
	246	}
247
248	/* convert from internal format to API */
249	memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
250	fe->port_no = f->dst->port_no;
251	fe->is_local = f->is_local;
252	if (!f->is_static)
253	fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer);
254	++fe;
255	++num;
256	}
257	}
258
259	out:
260	rcu_read_unlock();
261
262	return num;
263	}
264
265	static inline struct net_bridge_fdb_entry fdb_find(struct hlist_head head,
266	const unsigned char *addr)
267	{
268	struct hlist_node *h;
269	struct net_bridge_fdb_entry *fdb;
270
271	hlist_for_each_entry_rcu(fdb, h, head, hlist) {
6ede2463	272	if (!compare_ether_addr(fdb->addr.addr, addr))
1da177e4 LT	273	return fdb;
	274	}
	275	return NULL;
	276	}
	277
	278	static struct net_bridge_fdb_entry fdb_create(struct hlist_head head,
	279	struct net_bridge_port *source,
	280	const unsigned char *addr,
	281	int is_local)
	282	{
	283	struct net_bridge_fdb_entry *fdb;
	284
	285	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
	286	if (fdb) {
	287	memcpy(fdb->addr.addr, addr, ETH_ALEN);
	288	atomic_set(&fdb->use_count, 1);
	289	hlist_add_head_rcu(&fdb->hlist, head);
	290
	291	fdb->dst = source;
	292	fdb->is_local = is_local;
	293	fdb->is_static = is_local;
	294	fdb->ageing_timer = jiffies;
	295	}
	296	return fdb;
	297	}
	298
	299	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
	300	const unsigned char *addr)
	301	{
	302	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	303	struct net_bridge_fdb_entry *fdb;
	304
	305	if (!is_valid_ether_addr(addr))
	306	return -EINVAL;
	307
	308	fdb = fdb_find(head, addr);
	309	if (fdb) {
	310	/* it is okay to have multiple ports with same
	311	* address, just use the first one.
	312	*/
	313	if (fdb->is_local)
	314	return 0;
	315
	316	printk(KERN_WARNING "%s adding interface with same address "
	317	"as a received packet\n",
	318	source->dev->name);
	319	fdb_delete(fdb);
	320	}
	321
	322	if (!fdb_create(head, source, addr, 1))
	323	return -ENOMEM;
	324
	325	return 0;
	326	}
	327
	328	int br_fdb_insert(struct net_bridge br, struct net_bridge_port source,
	329	const unsigned char *addr)
	330	{
	331	int ret;
	332
	333	spin_lock_bh(&br->hash_lock);
	334	ret = fdb_insert(br, source, addr);
	335	spin_unlock_bh(&br->hash_lock);
	336	return ret;
337	}
338
339	void br_fdb_update(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	/* some users want to always flood. */
346	if (hold_time(br) == 0)
347	return;
348
1da177e4 LT	349	fdb = fdb_find(head, addr);
	350	if (likely(fdb)) {
	351	/* attempt to update an entry for a local interface */
	352	if (unlikely(fdb->is_local)) {
	353	if (net_ratelimit())
	354	printk(KERN_WARNING "%s: received packet with "
	355	" own address as source address\n",
	356	source->dev->name);
	357	} else {
	358	/* fastpath: update of existing entry */
	359	fdb->dst = source;
	360	fdb->ageing_timer = jiffies;
	361	}
	362	} else {
f8ae737d	363	spin_lock(&br->hash_lock);
1da177e4 LT	364	if (!fdb_find(head, addr))
	365	fdb_create(head, source, addr, 0);
	366	/* else we lose race and someone else inserts
	367	* it first, don't bother updating
	368	*/
f8ae737d	369	spin_unlock(&br->hash_lock);
1da177e4	370	}
1da177e4	371	}