blob: 57bf05c353bc804c58cffb5dc060c53850aacf79 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Forwarding database
3 * Linux ethernet bridge
4 *
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
7 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * 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>
Franck Bui-Huu82524742008-05-12 21:21:05 +020016#include <linux/rculist.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/spinlock.h>
18#include <linux/times.h>
19#include <linux/netdevice.h>
20#include <linux/etherdevice.h>
21#include <linux/jhash.h>
Stephen Hemminger3f890922007-03-21 13:42:33 -070022#include <linux/random.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <asm/atomic.h>
Stephen Hemminger3f890922007-03-21 13:42:33 -070024#include <asm/unaligned.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include "br_private.h"
26
Christoph Lametere18b8902006-12-06 20:33:20 -080027static struct kmem_cache *br_fdb_cache __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070028static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
29 const unsigned char *addr);
30
Stephen Hemminger3f890922007-03-21 13:42:33 -070031static u32 fdb_salt __read_mostly;
32
Akinobu Mita87a596e2007-04-07 18:57:07 +090033int __init br_fdb_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070034{
35 br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
36 sizeof(struct net_bridge_fdb_entry),
37 0,
Paul Mundt20c2df82007-07-20 10:11:58 +090038 SLAB_HWCACHE_ALIGN, NULL);
Akinobu Mita87a596e2007-04-07 18:57:07 +090039 if (!br_fdb_cache)
40 return -ENOMEM;
41
Stephen Hemminger3f890922007-03-21 13:42:33 -070042 get_random_bytes(&fdb_salt, sizeof(fdb_salt));
Akinobu Mita87a596e2007-04-07 18:57:07 +090043 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044}
45
Andrew Morton73afc902007-12-05 21:35:23 -080046void br_fdb_fini(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070047{
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 */
Stephen Hemminger3f890922007-03-21 13:42:33 -070055static inline unsigned long hold_time(const struct net_bridge *br)
Linus Torvalds1da177e2005-04-16 15:20:36 -070056{
57 return br->topology_change ? br->forward_delay : br->ageing_time;
58}
59
Stephen Hemminger3f890922007-03-21 13:42:33 -070060static inline int has_expired(const struct net_bridge *br,
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 const struct net_bridge_fdb_entry *fdb)
62{
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090063 return !fdb->is_static
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 && time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
65}
66
Stephen Hemminger3f890922007-03-21 13:42:33 -070067static inline int br_mac_hash(const unsigned char *mac)
Linus Torvalds1da177e2005-04-16 15:20:36 -070068{
Stephen Hemminger3f890922007-03-21 13:42:33 -070069 /* 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072}
73
Michał Mirosławda678292009-06-05 05:35:28 +000074static void fdb_rcu_free(struct rcu_head *head)
75{
76 struct net_bridge_fdb_entry *ent
77 = container_of(head, struct net_bridge_fdb_entry, rcu);
78 kmem_cache_free(br_fdb_cache, ent);
79}
80
Stephen Hemminger3f890922007-03-21 13:42:33 -070081static inline void fdb_delete(struct net_bridge_fdb_entry *f)
Linus Torvalds1da177e2005-04-16 15:20:36 -070082{
83 hlist_del_rcu(&f->hlist);
Michał Mirosławda678292009-06-05 05:35:28 +000084 call_rcu(&f->rcu, fdb_rcu_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085}
86
87void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
88{
89 struct net_bridge *br = p->br;
90 int i;
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090091
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 spin_lock_bh(&br->hash_lock);
93
94 /* Search all chains since old address/hash is unknown */
95 for (i = 0; i < BR_HASH_SIZE; i++) {
96 struct hlist_node *h;
97 hlist_for_each(h, &br->hash[i]) {
98 struct net_bridge_fdb_entry *f;
99
100 f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
101 if (f->dst == p && f->is_local) {
102 /* maybe another port has same hw addr? */
103 struct net_bridge_port *op;
104 list_for_each_entry(op, &br->port_list, list) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900105 if (op != p &&
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700106 !compare_ether_addr(op->dev->dev_addr,
107 f->addr.addr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 f->dst = op;
109 goto insert;
110 }
111 }
112
113 /* delete old one */
114 fdb_delete(f);
115 goto insert;
116 }
117 }
118 }
119 insert:
120 /* insert new address, may fail if invalid address or dup. */
121 fdb_insert(br, p, newaddr);
122
123 spin_unlock_bh(&br->hash_lock);
124}
125
126void br_fdb_cleanup(unsigned long _data)
127{
128 struct net_bridge *br = (struct net_bridge *)_data;
129 unsigned long delay = hold_time(br);
Baruch Even071f7722007-05-31 01:20:45 -0700130 unsigned long next_timer = jiffies + br->forward_delay;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 int i;
132
133 spin_lock_bh(&br->hash_lock);
134 for (i = 0; i < BR_HASH_SIZE; i++) {
135 struct net_bridge_fdb_entry *f;
136 struct hlist_node *h, *n;
137
138 hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
Baruch Even071f7722007-05-31 01:20:45 -0700139 unsigned long this_timer;
140 if (f->is_static)
141 continue;
142 this_timer = f->ageing_timer + delay;
143 if (time_before_eq(this_timer, jiffies))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 fdb_delete(f);
Fabio Checconi2bec0082008-03-20 15:54:58 -0700145 else if (time_before(this_timer, next_timer))
Baruch Even071f7722007-05-31 01:20:45 -0700146 next_timer = this_timer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 }
148 }
149 spin_unlock_bh(&br->hash_lock);
150
Baruch Even071f7722007-05-31 01:20:45 -0700151 /* Add HZ/4 to ensure we round the jiffies upwards to be after the next
152 * timer, otherwise we might round down and will have no-op run. */
153 mod_timer(&br->gc_timer, round_jiffies(next_timer + HZ/4));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154}
155
Stephen Hemminger9cf63742007-04-09 12:57:54 -0700156/* Completely flush all dynamic entries in forwarding database.*/
157void br_fdb_flush(struct net_bridge *br)
158{
159 int i;
Stephen Hemminger1a620692006-10-12 14:45:38 -0700160
Stephen Hemminger9cf63742007-04-09 12:57:54 -0700161 spin_lock_bh(&br->hash_lock);
162 for (i = 0; i < BR_HASH_SIZE; i++) {
163 struct net_bridge_fdb_entry *f;
164 struct hlist_node *h, *n;
165 hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
166 if (!f->is_static)
167 fdb_delete(f);
168 }
169 }
170 spin_unlock_bh(&br->hash_lock);
171}
172
173/* Flush all entries refering to a specific port.
174 * if do_all is set also flush static entries
175 */
Stephen Hemminger1a620692006-10-12 14:45:38 -0700176void br_fdb_delete_by_port(struct net_bridge *br,
177 const struct net_bridge_port *p,
178 int do_all)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
180 int i;
181
182 spin_lock_bh(&br->hash_lock);
183 for (i = 0; i < BR_HASH_SIZE; i++) {
184 struct hlist_node *h, *g;
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900185
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 hlist_for_each_safe(h, g, &br->hash[i]) {
187 struct net_bridge_fdb_entry *f
188 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900189 if (f->dst != p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 continue;
191
Stephen Hemminger1a620692006-10-12 14:45:38 -0700192 if (f->is_static && !do_all)
193 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 /*
195 * if multiple ports all have the same device address
196 * then when one port is deleted, assign
197 * the local entry to other port
198 */
199 if (f->is_local) {
200 struct net_bridge_port *op;
201 list_for_each_entry(op, &br->port_list, list) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900202 if (op != p &&
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700203 !compare_ether_addr(op->dev->dev_addr,
204 f->addr.addr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 f->dst = op;
206 goto skip_delete;
207 }
208 }
209 }
210
211 fdb_delete(f);
212 skip_delete: ;
213 }
214 }
215 spin_unlock_bh(&br->hash_lock);
216}
217
218/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
219struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
220 const unsigned char *addr)
221{
222 struct hlist_node *h;
223 struct net_bridge_fdb_entry *fdb;
224
225 hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700226 if (!compare_ether_addr(fdb->addr.addr, addr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 if (unlikely(has_expired(br, fdb)))
228 break;
229 return fdb;
230 }
231 }
232
233 return NULL;
234}
235
Michał Mirosławda678292009-06-05 05:35:28 +0000236#if defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE)
237/* Interface used by ATM LANE hook to test
238 * if an addr is on some other bridge port */
239int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240{
241 struct net_bridge_fdb_entry *fdb;
Michał Mirosławda678292009-06-05 05:35:28 +0000242 int ret;
243
244 if (!dev->br_port)
245 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
247 rcu_read_lock();
Michał Mirosławda678292009-06-05 05:35:28 +0000248 fdb = __br_fdb_get(dev->br_port->br, addr);
249 ret = fdb && fdb->dst->dev != dev &&
250 fdb->dst->state == BR_STATE_FORWARDING;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
Michał Mirosławda678292009-06-05 05:35:28 +0000253 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254}
Michał Mirosławda678292009-06-05 05:35:28 +0000255#endif /* CONFIG_ATM_LANE */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
257/*
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900258 * Fill buffer with forwarding table records in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 * the API format.
260 */
261int 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
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900277 if (has_expired(br, f))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 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);
Stephen Hemmingerae4f8fc2008-05-02 16:53:33 -0700287
288 /* due to ABI compat need to split into hi/lo */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 fe->port_no = f->dst->port_no;
Stephen Hemmingerae4f8fc2008-05-02 16:53:33 -0700290 fe->port_hi = f->dst->port_no >> 8;
291
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 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
306static 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) {
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700313 if (!compare_ether_addr(fdb->addr.addr, addr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 return fdb;
315 }
316 return NULL;
317}
318
319static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
320 struct net_bridge_port *source,
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900321 const unsigned char *addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 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
339static 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) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900350 /* it is okay to have multiple ports with same
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 * address, just use the first one.
352 */
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900353 if (fdb->is_local)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 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);
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900360 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
362 if (!fdb_create(head, source, addr, 1))
363 return -ENOMEM;
364
365 return 0;
366}
367
368int 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
379void 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
Stephen Hemmingerdf1c0b82007-08-30 22:15:35 -0700389 /* ignore packets unless we are using this port */
390 if (!(source->state == BR_STATE_LEARNING ||
391 source->state == BR_STATE_FORWARDING))
392 return;
393
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 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)) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900398 if (net_ratelimit())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 printk(KERN_WARNING "%s: received packet with "
Jiri Pirko0bb32412009-05-27 00:55:08 +0000400 "own address as source address\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 source->dev->name);
402 } else {
403 /* fastpath: update of existing entry */
404 fdb->dst = source;
405 fdb->ageing_timer = jiffies;
406 }
407 } else {
Stephen Hemmingerf8ae7372006-03-20 22:58:36 -0800408 spin_lock(&br->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 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 */
Stephen Hemmingerf8ae7372006-03-20 22:58:36 -0800414 spin_unlock(&br->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416}