Linux 2.6.31.6
[linux/fpc-iii.git] / net / bridge / br_fdb.c
blob57bf05c353bc804c58cffb5dc060c53850aacf79
1 /*
2 * Forwarding database
3 * Linux ethernet bridge
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
8 * 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.
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/rculist.h>
17 #include <linux/spinlock.h>
18 #include <linux/times.h>
19 #include <linux/netdevice.h>
20 #include <linux/etherdevice.h>
21 #include <linux/jhash.h>
22 #include <linux/random.h>
23 #include <asm/atomic.h>
24 #include <asm/unaligned.h>
25 #include "br_private.h"
27 static struct kmem_cache *br_fdb_cache __read_mostly;
28 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
29 const unsigned char *addr);
31 static u32 fdb_salt __read_mostly;
33 int __init br_fdb_init(void)
35 br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
36 sizeof(struct net_bridge_fdb_entry),
38 SLAB_HWCACHE_ALIGN, NULL);
39 if (!br_fdb_cache)
40 return -ENOMEM;
42 get_random_bytes(&fdb_salt, sizeof(fdb_salt));
43 return 0;
46 void br_fdb_fini(void)
48 kmem_cache_destroy(br_fdb_cache);
52 /* if topology_changing then use forward_delay (default 15 sec)
53 * otherwise keep longer (default 5 minutes)
55 static inline unsigned long hold_time(const struct net_bridge *br)
57 return br->topology_change ? br->forward_delay : br->ageing_time;
60 static inline int has_expired(const struct net_bridge *br,
61 const struct net_bridge_fdb_entry *fdb)
63 return !fdb->is_static
64 && time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
67 static inline int br_mac_hash(const unsigned char *mac)
69 /* 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);
74 static void fdb_rcu_free(struct rcu_head *head)
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);
81 static inline void fdb_delete(struct net_bridge_fdb_entry *f)
83 hlist_del_rcu(&f->hlist);
84 call_rcu(&f->rcu, fdb_rcu_free);
87 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
89 struct net_bridge *br = p->br;
90 int i;
92 spin_lock_bh(&br->hash_lock);
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;
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) {
105 if (op != p &&
106 !compare_ether_addr(op->dev->dev_addr,
107 f->addr.addr)) {
108 f->dst = op;
109 goto insert;
113 /* delete old one */
114 fdb_delete(f);
115 goto insert;
119 insert:
120 /* insert new address, may fail if invalid address or dup. */
121 fdb_insert(br, p, newaddr);
123 spin_unlock_bh(&br->hash_lock);
126 void br_fdb_cleanup(unsigned long _data)
128 struct net_bridge *br = (struct net_bridge *)_data;
129 unsigned long delay = hold_time(br);
130 unsigned long next_timer = jiffies + br->forward_delay;
131 int i;
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;
138 hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
139 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))
144 fdb_delete(f);
145 else if (time_before(this_timer, next_timer))
146 next_timer = this_timer;
149 spin_unlock_bh(&br->hash_lock);
151 /* 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));
156 /* Completely flush all dynamic entries in forwarding database.*/
157 void br_fdb_flush(struct net_bridge *br)
159 int i;
161 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);
170 spin_unlock_bh(&br->hash_lock);
173 /* Flush all entries refering to a specific port.
174 * if do_all is set also flush static entries
176 void br_fdb_delete_by_port(struct net_bridge *br,
177 const struct net_bridge_port *p,
178 int do_all)
180 int i;
182 spin_lock_bh(&br->hash_lock);
183 for (i = 0; i < BR_HASH_SIZE; i++) {
184 struct hlist_node *h, *g;
186 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);
189 if (f->dst != p)
190 continue;
192 if (f->is_static && !do_all)
193 continue;
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
199 if (f->is_local) {
200 struct net_bridge_port *op;
201 list_for_each_entry(op, &br->port_list, list) {
202 if (op != p &&
203 !compare_ether_addr(op->dev->dev_addr,
204 f->addr.addr)) {
205 f->dst = op;
206 goto skip_delete;
211 fdb_delete(f);
212 skip_delete: ;
215 spin_unlock_bh(&br->hash_lock);
218 /* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
219 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
220 const unsigned char *addr)
222 struct hlist_node *h;
223 struct net_bridge_fdb_entry *fdb;
225 hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
226 if (!compare_ether_addr(fdb->addr.addr, addr)) {
227 if (unlikely(has_expired(br, fdb)))
228 break;
229 return fdb;
233 return NULL;
236 #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 */
239 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
241 struct net_bridge_fdb_entry *fdb;
242 int ret;
244 if (!dev->br_port)
245 return 0;
247 rcu_read_lock();
248 fdb = __br_fdb_get(dev->br_port->br, addr);
249 ret = fdb && fdb->dst->dev != dev &&
250 fdb->dst->state == BR_STATE_FORWARDING;
251 rcu_read_unlock();
253 return ret;
255 #endif /* CONFIG_ATM_LANE */
258 * Fill buffer with forwarding table records in
259 * the API format.
261 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
262 unsigned long maxnum, unsigned long skip)
264 struct __fdb_entry *fe = buf;
265 int i, num = 0;
266 struct hlist_node *h;
267 struct net_bridge_fdb_entry *f;
269 memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
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;
277 if (has_expired(br, f))
278 continue;
280 if (skip) {
281 --skip;
282 continue;
285 /* convert from internal format to API */
286 memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
288 /* due to ABI compat need to split into hi/lo */
289 fe->port_no = f->dst->port_no;
290 fe->port_hi = f->dst->port_no >> 8;
292 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;
300 out:
301 rcu_read_unlock();
303 return num;
306 static inline struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
307 const unsigned char *addr)
309 struct hlist_node *h;
310 struct net_bridge_fdb_entry *fdb;
312 hlist_for_each_entry_rcu(fdb, h, head, hlist) {
313 if (!compare_ether_addr(fdb->addr.addr, addr))
314 return fdb;
316 return NULL;
319 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
320 struct net_bridge_port *source,
321 const unsigned char *addr,
322 int is_local)
324 struct net_bridge_fdb_entry *fdb;
326 fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
327 if (fdb) {
328 memcpy(fdb->addr.addr, addr, ETH_ALEN);
329 hlist_add_head_rcu(&fdb->hlist, head);
331 fdb->dst = source;
332 fdb->is_local = is_local;
333 fdb->is_static = is_local;
334 fdb->ageing_timer = jiffies;
336 return fdb;
339 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
340 const unsigned char *addr)
342 struct hlist_head *head = &br->hash[br_mac_hash(addr)];
343 struct net_bridge_fdb_entry *fdb;
345 if (!is_valid_ether_addr(addr))
346 return -EINVAL;
348 fdb = fdb_find(head, addr);
349 if (fdb) {
350 /* it is okay to have multiple ports with same
351 * address, just use the first one.
353 if (fdb->is_local)
354 return 0;
356 printk(KERN_WARNING "%s adding interface with same address "
357 "as a received packet\n",
358 source->dev->name);
359 fdb_delete(fdb);
362 if (!fdb_create(head, source, addr, 1))
363 return -ENOMEM;
365 return 0;
368 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
369 const unsigned char *addr)
371 int ret;
373 spin_lock_bh(&br->hash_lock);
374 ret = fdb_insert(br, source, addr);
375 spin_unlock_bh(&br->hash_lock);
376 return ret;
379 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
380 const unsigned char *addr)
382 struct hlist_head *head = &br->hash[br_mac_hash(addr)];
383 struct net_bridge_fdb_entry *fdb;
385 /* some users want to always flood. */
386 if (hold_time(br) == 0)
387 return;
389 /* ignore packets unless we are using this port */
390 if (!(source->state == BR_STATE_LEARNING ||
391 source->state == BR_STATE_FORWARDING))
392 return;
394 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)) {
398 if (net_ratelimit())
399 printk(KERN_WARNING "%s: received packet with "
400 "own address as source address\n",
401 source->dev->name);
402 } else {
403 /* fastpath: update of existing entry */
404 fdb->dst = source;
405 fdb->ageing_timer = jiffies;
407 } else {
408 spin_lock(&br->hash_lock);
409 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
414 spin_unlock(&br->hash_lock);