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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 *
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
Christoph Lametere18b8902006-12-06 20:33:20 -080026static struct kmem_cache *br_fdb_cache __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070027static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
28 const unsigned char *addr);
29
30void __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
38void __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 */
47static __inline__ unsigned long hold_time(const struct net_bridge *br)
48{
49 return br->topology_change ? br->forward_delay : br->ageing_time;
50}
51
52static __inline__ int has_expired(const struct net_bridge *br,
53 const struct net_bridge_fdb_entry *fdb)
54{
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090055 return !fdb->is_static
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 && time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
57}
58
59static __inline__ int br_mac_hash(const unsigned char *mac)
60{
61 return jhash(mac, ETH_ALEN, 0) & (BR_HASH_SIZE - 1);
62}
63
64static __inline__ void fdb_delete(struct net_bridge_fdb_entry *f)
65{
66 hlist_del_rcu(&f->hlist);
67 br_fdb_put(f);
68}
69
70void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
71{
72 struct net_bridge *br = p->br;
73 int i;
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090074
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 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) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090088 if (op != p &&
Stephen Hemminger6ede2462005-10-25 15:04:59 -070089 !compare_ether_addr(op->dev->dev_addr,
90 f->addr.addr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 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
109void 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) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900121 if (!f->is_static &&
122 time_before_eq(f->ageing_timer + delay, jiffies))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 fdb_delete(f);
124 }
125 }
126 spin_unlock_bh(&br->hash_lock);
127
128 mod_timer(&br->gc_timer, jiffies + HZ/10);
129}
130
Stephen Hemminger1a620692006-10-12 14:45:38 -0700131
132void br_fdb_delete_by_port(struct net_bridge *br,
133 const struct net_bridge_port *p,
134 int do_all)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135{
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;
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900141
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 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);
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900145 if (f->dst != p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 continue;
147
Stephen Hemminger1a620692006-10-12 14:45:38 -0700148 if (f->is_static && !do_all)
149 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 /*
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) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900158 if (op != p &&
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700159 !compare_ether_addr(op->dev->dev_addr,
160 f->addr.addr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 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) */
175struct 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) {
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700182 if (!compare_ether_addr(fdb->addr.addr, addr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 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 */
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900193struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 unsigned char *addr)
195{
196 struct net_bridge_fdb_entry *fdb;
197
198 rcu_read_lock();
199 fdb = __br_fdb_get(br, addr);
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900200 if (fdb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 atomic_inc(&fdb->use_count);
202 rcu_read_unlock();
203 return fdb;
204}
205
206static 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 */
214void 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/*
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900221 * Fill buffer with forwarding table records in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 * the API format.
223 */
224int 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
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900240 if (has_expired(br, f))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 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
265static 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) {
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700272 if (!compare_ether_addr(fdb->addr.addr, addr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 return fdb;
274 }
275 return NULL;
276}
277
278static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
279 struct net_bridge_port *source,
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900280 const unsigned char *addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 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
299static 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) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900310 /* it is okay to have multiple ports with same
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 * address, just use the first one.
312 */
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900313 if (fdb->is_local)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 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);
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900320 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321
322 if (!fdb_create(head, source, addr, 1))
323 return -ENOMEM;
324
325 return 0;
326}
327
328int 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
339void 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 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)) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900353 if (net_ratelimit())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 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 {
Stephen Hemmingerf8ae7372006-03-20 22:58:36 -0800363 spin_lock(&br->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 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 */
Stephen Hemmingerf8ae7372006-03-20 22:58:36 -0800369 spin_unlock(&br->hash_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371}