blob: 9101a4e5620129fa4d29df1a7e2cbde264cf88f2 [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <asm/atomic.h>
Stephen Hemminger3f890922007-03-21 13:42:33 -070025#include <asm/unaligned.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include "br_private.h"
27
Christoph Lametere18b8902006-12-06 20:33:20 -080028static struct kmem_cache *br_fdb_cache __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
30 const unsigned char *addr);
31
Stephen Hemminger3f890922007-03-21 13:42:33 -070032static u32 fdb_salt __read_mostly;
33
Akinobu Mita87a596e2007-04-07 18:57:07 +090034int __init br_fdb_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070035{
36 br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
37 sizeof(struct net_bridge_fdb_entry),
38 0,
Paul Mundt20c2df82007-07-20 10:11:58 +090039 SLAB_HWCACHE_ALIGN, NULL);
Akinobu Mita87a596e2007-04-07 18:57:07 +090040 if (!br_fdb_cache)
41 return -ENOMEM;
42
Stephen Hemminger3f890922007-03-21 13:42:33 -070043 get_random_bytes(&fdb_salt, sizeof(fdb_salt));
Akinobu Mita87a596e2007-04-07 18:57:07 +090044 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070045}
46
Andrew Morton73afc902007-12-05 21:35:23 -080047void br_fdb_fini(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048{
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 */
Stephen Hemminger3f890922007-03-21 13:42:33 -070056static inline unsigned long hold_time(const struct net_bridge *br)
Linus Torvalds1da177e2005-04-16 15:20:36 -070057{
58 return br->topology_change ? br->forward_delay : br->ageing_time;
59}
60
Stephen Hemminger3f890922007-03-21 13:42:33 -070061static inline int has_expired(const struct net_bridge *br,
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 const struct net_bridge_fdb_entry *fdb)
63{
Joe Perchesf64f9e72009-11-29 16:55:45 -080064 return !fdb->is_static &&
65 time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066}
67
Stephen Hemminger3f890922007-03-21 13:42:33 -070068static inline int br_mac_hash(const unsigned char *mac)
Linus Torvalds1da177e2005-04-16 15:20:36 -070069{
Stephen Hemminger3f890922007-03-21 13:42:33 -070070 /* 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073}
74
Michał Mirosławda678292009-06-05 05:35:28 +000075static 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
Stephen Hemminger3f890922007-03-21 13:42:33 -070082static inline void fdb_delete(struct net_bridge_fdb_entry *f)
Linus Torvalds1da177e2005-04-16 15:20:36 -070083{
84 hlist_del_rcu(&f->hlist);
Michał Mirosławda678292009-06-05 05:35:28 +000085 call_rcu(&f->rcu, fdb_rcu_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086}
87
88void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
89{
90 struct net_bridge *br = p->br;
91 int i;
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090092
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 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) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900106 if (op != p &&
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700107 !compare_ether_addr(op->dev->dev_addr,
108 f->addr.addr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 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
127void br_fdb_cleanup(unsigned long _data)
128{
129 struct net_bridge *br = (struct net_bridge *)_data;
130 unsigned long delay = hold_time(br);
Baruch Even071f7722007-05-31 01:20:45 -0700131 unsigned long next_timer = jiffies + br->forward_delay;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 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) {
Baruch Even071f7722007-05-31 01:20:45 -0700140 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))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 fdb_delete(f);
Fabio Checconi2bec0082008-03-20 15:54:58 -0700146 else if (time_before(this_timer, next_timer))
Baruch Even071f7722007-05-31 01:20:45 -0700147 next_timer = this_timer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 }
149 }
150 spin_unlock_bh(&br->hash_lock);
151
Baruch Even071f7722007-05-31 01:20:45 -0700152 /* Add HZ/4 to ensure we round the jiffies upwards to be after the next
153 * timer, otherwise we might round down and will have no-op run. */
154 mod_timer(&br->gc_timer, round_jiffies(next_timer + HZ/4));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155}
156
Stephen Hemminger9cf63742007-04-09 12:57:54 -0700157/* Completely flush all dynamic entries in forwarding database.*/
158void br_fdb_flush(struct net_bridge *br)
159{
160 int i;
Stephen Hemminger1a620692006-10-12 14:45:38 -0700161
Stephen Hemminger9cf63742007-04-09 12:57:54 -0700162 spin_lock_bh(&br->hash_lock);
163 for (i = 0; i < BR_HASH_SIZE; i++) {
164 struct net_bridge_fdb_entry *f;
165 struct hlist_node *h, *n;
166 hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
167 if (!f->is_static)
168 fdb_delete(f);
169 }
170 }
171 spin_unlock_bh(&br->hash_lock);
172}
173
174/* Flush all entries refering to a specific port.
175 * if do_all is set also flush static entries
176 */
Stephen Hemminger1a620692006-10-12 14:45:38 -0700177void br_fdb_delete_by_port(struct net_bridge *br,
178 const struct net_bridge_port *p,
179 int do_all)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
181 int i;
182
183 spin_lock_bh(&br->hash_lock);
184 for (i = 0; i < BR_HASH_SIZE; i++) {
185 struct hlist_node *h, *g;
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 hlist_for_each_safe(h, g, &br->hash[i]) {
188 struct net_bridge_fdb_entry *f
189 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900190 if (f->dst != p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 continue;
192
Stephen Hemminger1a620692006-10-12 14:45:38 -0700193 if (f->is_static && !do_all)
194 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 /*
196 * if multiple ports all have the same device address
197 * then when one port is deleted, assign
198 * the local entry to other port
199 */
200 if (f->is_local) {
201 struct net_bridge_port *op;
202 list_for_each_entry(op, &br->port_list, list) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900203 if (op != p &&
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700204 !compare_ether_addr(op->dev->dev_addr,
205 f->addr.addr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 f->dst = op;
207 goto skip_delete;
208 }
209 }
210 }
211
212 fdb_delete(f);
213 skip_delete: ;
214 }
215 }
216 spin_unlock_bh(&br->hash_lock);
217}
218
219/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
220struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
221 const unsigned char *addr)
222{
223 struct hlist_node *h;
224 struct net_bridge_fdb_entry *fdb;
225
226 hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700227 if (!compare_ether_addr(fdb->addr.addr, addr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 if (unlikely(has_expired(br, fdb)))
229 break;
230 return fdb;
231 }
232 }
233
234 return NULL;
235}
236
Michał Mirosławda678292009-06-05 05:35:28 +0000237#if defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE)
238/* Interface used by ATM LANE hook to test
239 * if an addr is on some other bridge port */
240int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241{
242 struct net_bridge_fdb_entry *fdb;
Michał Mirosławda678292009-06-05 05:35:28 +0000243 int ret;
244
245 if (!dev->br_port)
246 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
248 rcu_read_lock();
Michał Mirosławda678292009-06-05 05:35:28 +0000249 fdb = __br_fdb_get(dev->br_port->br, addr);
250 ret = fdb && fdb->dst->dev != dev &&
251 fdb->dst->state == BR_STATE_FORWARDING;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
Michał Mirosławda678292009-06-05 05:35:28 +0000254 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255}
Michał Mirosławda678292009-06-05 05:35:28 +0000256#endif /* CONFIG_ATM_LANE */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258/*
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900259 * Fill buffer with forwarding table records in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 * the API format.
261 */
262int br_fdb_fillbuf(struct net_bridge *br, void *buf,
263 unsigned long maxnum, unsigned long skip)
264{
265 struct __fdb_entry *fe = buf;
266 int i, num = 0;
267 struct hlist_node *h;
268 struct net_bridge_fdb_entry *f;
269
270 memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
271
272 rcu_read_lock();
273 for (i = 0; i < BR_HASH_SIZE; i++) {
274 hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
275 if (num >= maxnum)
276 goto out;
277
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900278 if (has_expired(br, f))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 continue;
280
281 if (skip) {
282 --skip;
283 continue;
284 }
285
286 /* convert from internal format to API */
287 memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
Stephen Hemmingerae4f8fc2008-05-02 16:53:33 -0700288
289 /* due to ABI compat need to split into hi/lo */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 fe->port_no = f->dst->port_no;
Stephen Hemmingerae4f8fc2008-05-02 16:53:33 -0700291 fe->port_hi = f->dst->port_no >> 8;
292
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 fe->is_local = f->is_local;
294 if (!f->is_static)
295 fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer);
296 ++fe;
297 ++num;
298 }
299 }
300
301 out:
302 rcu_read_unlock();
303
304 return num;
305}
306
307static inline struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
308 const unsigned char *addr)
309{
310 struct hlist_node *h;
311 struct net_bridge_fdb_entry *fdb;
312
313 hlist_for_each_entry_rcu(fdb, h, head, hlist) {
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700314 if (!compare_ether_addr(fdb->addr.addr, addr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 return fdb;
316 }
317 return NULL;
318}
319
320static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
321 struct net_bridge_port *source,
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900322 const unsigned char *addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 int is_local)
324{
325 struct net_bridge_fdb_entry *fdb;
326
327 fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
328 if (fdb) {
329 memcpy(fdb->addr.addr, addr, ETH_ALEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 hlist_add_head_rcu(&fdb->hlist, head);
331
332 fdb->dst = source;
333 fdb->is_local = is_local;
334 fdb->is_static = is_local;
335 fdb->ageing_timer = jiffies;
336 }
337 return fdb;
338}
339
340static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
341 const unsigned char *addr)
342{
343 struct hlist_head *head = &br->hash[br_mac_hash(addr)];
344 struct net_bridge_fdb_entry *fdb;
345
346 if (!is_valid_ether_addr(addr))
347 return -EINVAL;
348
349 fdb = fdb_find(head, addr);
350 if (fdb) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900351 /* it is okay to have multiple ports with same
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 * address, just use the first one.
353 */
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900354 if (fdb->is_local)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 return 0;
356
357 printk(KERN_WARNING "%s adding interface with same address "
358 "as a received packet\n",
359 source->dev->name);
360 fdb_delete(fdb);
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900361 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
363 if (!fdb_create(head, source, addr, 1))
364 return -ENOMEM;
365
366 return 0;
367}
368
369int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
370 const unsigned char *addr)
371{
372 int ret;
373
374 spin_lock_bh(&br->hash_lock);
375 ret = fdb_insert(br, source, addr);
376 spin_unlock_bh(&br->hash_lock);
377 return ret;
378}
379
380void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
381 const unsigned char *addr)
382{
383 struct hlist_head *head = &br->hash[br_mac_hash(addr)];
384 struct net_bridge_fdb_entry *fdb;
385
386 /* some users want to always flood. */
387 if (hold_time(br) == 0)
388 return;
389
Stephen Hemmingerdf1c0b82007-08-30 22:15:35 -0700390 /* ignore packets unless we are using this port */
391 if (!(source->state == BR_STATE_LEARNING ||
392 source->state == BR_STATE_FORWARDING))
393 return;
394
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 fdb = fdb_find(head, addr);
396 if (likely(fdb)) {
397 /* attempt to update an entry for a local interface */
398 if (unlikely(fdb->is_local)) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900399 if (net_ratelimit())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 printk(KERN_WARNING "%s: received packet with "
Jiri Pirko0bb32412009-05-27 00:55:08 +0000401 "own address as source address\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 source->dev->name);
403 } else {
404 /* fastpath: update of existing entry */
405 fdb->dst = source;
406 fdb->ageing_timer = jiffies;
407 }
408 } else {
Stephen Hemmingerf8ae7372006-03-20 22:58:36 -0800409 spin_lock(&br->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 if (!fdb_find(head, addr))
411 fdb_create(head, source, addr, 0);
412 /* else we lose race and someone else inserts
413 * it first, don't bother updating
414 */
Stephen Hemmingerf8ae7372006-03-20 22:58:36 -0800415 spin_unlock(&br->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417}