[net-next-2.6.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 kmem_cache_t *br_fdb_cache;
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 && 
					    !memcmp(op->dev->dev_addr,
						    f->addr.addr, ETH_ALEN)) {
						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, struct net_bridge_port *p)
{
	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 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 && 
					    !memcmp(op->dev->dev_addr,
						    f->addr.addr, ETH_ALEN)) {
						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 (!memcmp(fdb->addr.addr, addr, ETH_ALEN)) {
			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 (!memcmp(fdb->addr.addr, addr, ETH_ALEN))
			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;

	rcu_read_lock();
	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_bh(&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_bh(&br->hash_lock);
	}
	rcu_read_unlock();
}
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
	26	static kmem_cache_t *br_fdb_cache;
	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 &&
89	!memcmp(op->dev->dev_addr,
90	f->addr.addr, ETH_ALEN)) {
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
131	void br_fdb_delete_by_port(struct net_bridge br, struct net_bridge_port p)
132	{
133	int i;
134
135	spin_lock_bh(&br->hash_lock);
136	for (i = 0; i < BR_HASH_SIZE; i++) {
137	struct hlist_node h, g;
138
139	hlist_for_each_safe(h, g, &br->hash[i]) {
140	struct net_bridge_fdb_entry *f
141	= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
142	if (f->dst != p)
143	continue;
144
145	/*
146	* if multiple ports all have the same device address
147	* then when one port is deleted, assign
148	* the local entry to other port
149	*/
150	if (f->is_local) {
151	struct net_bridge_port *op;
152	list_for_each_entry(op, &br->port_list, list) {
153	if (op != p &&
154	!memcmp(op->dev->dev_addr,
155	f->addr.addr, ETH_ALEN)) {
156	f->dst = op;
157	goto skip_delete;
158	}
159	}
160	}
161
162	fdb_delete(f);
163	skip_delete: ;
164	}
165	}
166	spin_unlock_bh(&br->hash_lock);
167	}
168
169	/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
170	struct net_bridge_fdb_entry __br_fdb_get(struct net_bridge br,
171	const unsigned char *addr)
172	{
173	struct hlist_node *h;
174	struct net_bridge_fdb_entry *fdb;
175
176	hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
177	if (!memcmp(fdb->addr.addr, addr, ETH_ALEN)) {
178	if (unlikely(has_expired(br, fdb)))
179	break;
180	return fdb;
181	}
182	}
183
184	return NULL;
185	}
186
187	/* Interface used by ATM hook that keeps a ref count */
188	struct net_bridge_fdb_entry br_fdb_get(struct net_bridge br,
189	unsigned char *addr)
190	{
191	struct net_bridge_fdb_entry *fdb;
192
193	rcu_read_lock();
194	fdb = __br_fdb_get(br, addr);
195	if (fdb)
196	atomic_inc(&fdb->use_count);
197	rcu_read_unlock();
198	return fdb;
199	}
200
201	static void fdb_rcu_free(struct rcu_head *head)
202	{
203	struct net_bridge_fdb_entry *ent
204	= container_of(head, struct net_bridge_fdb_entry, rcu);
205	kmem_cache_free(br_fdb_cache, ent);
206	}
207
208	/* Set entry up for deletion with RCU */
209	void br_fdb_put(struct net_bridge_fdb_entry *ent)
210	{
211	if (atomic_dec_and_test(&ent->use_count))
212	call_rcu(&ent->rcu, fdb_rcu_free);
213	}
214
215	/*
216	* Fill buffer with forwarding table records in
217	* the API format.
218	*/
219	int br_fdb_fillbuf(struct net_bridge br, void buf,
220	unsigned long maxnum, unsigned long skip)
221	{
222	struct __fdb_entry *fe = buf;
223	int i, num = 0;
224	struct hlist_node *h;
225	struct net_bridge_fdb_entry *f;
226
227	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
228
229	rcu_read_lock();
230	for (i = 0; i < BR_HASH_SIZE; i++) {
231	hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
232	if (num >= maxnum)
233	goto out;
234
235	if (has_expired(br, f))
236	continue;
237
238	if (skip) {
239	--skip;
240	continue;
241	}
242
243	/* convert from internal format to API */
244	memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
245	fe->port_no = f->dst->port_no;
246	fe->is_local = f->is_local;
247	if (!f->is_static)
248	fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer);
249	++fe;
250	++num;
251	}
252	}
253
254	out:
255	rcu_read_unlock();
256
257	return num;
258	}
259
260	static inline struct net_bridge_fdb_entry fdb_find(struct hlist_head head,
261	const unsigned char *addr)
262	{
263	struct hlist_node *h;
264	struct net_bridge_fdb_entry *fdb;
265
266	hlist_for_each_entry_rcu(fdb, h, head, hlist) {
267	if (!memcmp(fdb->addr.addr, addr, ETH_ALEN))
268	return fdb;
269	}
270	return NULL;
271	}
272
273	static struct net_bridge_fdb_entry fdb_create(struct hlist_head head,
274	struct net_bridge_port *source,
275	const unsigned char *addr,
276	int is_local)
277	{
278	struct net_bridge_fdb_entry *fdb;
279
280	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
281	if (fdb) {
282	memcpy(fdb->addr.addr, addr, ETH_ALEN);
283	atomic_set(&fdb->use_count, 1);
284	hlist_add_head_rcu(&fdb->hlist, head);
285
286	fdb->dst = source;
287	fdb->is_local = is_local;
288	fdb->is_static = is_local;
289	fdb->ageing_timer = jiffies;
290	}
291	return fdb;
292	}
293
294	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
295	const unsigned char *addr)
296	{
297	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
298	struct net_bridge_fdb_entry *fdb;
299
300	if (!is_valid_ether_addr(addr))
301	return -EINVAL;
302
303	fdb = fdb_find(head, addr);
304	if (fdb) {
305	/* it is okay to have multiple ports with same
306	* address, just use the first one.
307	*/
308	if (fdb->is_local)
309	return 0;
310
311	printk(KERN_WARNING "%s adding interface with same address "
312	"as a received packet\n",
313	source->dev->name);
314	fdb_delete(fdb);
315	}
316
317	if (!fdb_create(head, source, addr, 1))
318	return -ENOMEM;
319
320	return 0;
321	}
322
323	int br_fdb_insert(struct net_bridge br, struct net_bridge_port source,
324	const unsigned char *addr)
325	{
326	int ret;
327
328	spin_lock_bh(&br->hash_lock);
329	ret = fdb_insert(br, source, addr);
330	spin_unlock_bh(&br->hash_lock);
331	return ret;
332	}
333
334	void br_fdb_update(struct net_bridge br, struct net_bridge_port source,
335	const unsigned char *addr)
336	{
337	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
338	struct net_bridge_fdb_entry *fdb;
339
340	/* some users want to always flood. */
341	if (hold_time(br) == 0)
342	return;
343
344	rcu_read_lock();
345	fdb = fdb_find(head, addr);
346	if (likely(fdb)) {
347	/* attempt to update an entry for a local interface */
348	if (unlikely(fdb->is_local)) {
349	if (net_ratelimit())
350	printk(KERN_WARNING "%s: received packet with "
351	" own address as source address\n",
352	source->dev->name);
353	} else {
354	/* fastpath: update of existing entry */
355	fdb->dst = source;
356	fdb->ageing_timer = jiffies;
357	}
358	} else {
359	spin_lock_bh(&br->hash_lock);
360	if (!fdb_find(head, addr))
361	fdb_create(head, source, addr, 0);
362	/* else we lose race and someone else inserts
363	* it first, don't bother updating
364	*/
365	spin_unlock_bh(&br->hash_lock);
366	}
367	rcu_read_unlock();
368	}