sched: move the __update_rq_clock() call to scheduler_tick()
[usb.git] / net / bridge / br_fdb.c
blob69b70977f00061610b30fc86475e167bf49f4ee0
1 /*
2 * Forwarding database
3 * Linux ethernet bridge
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
8 * $Id: br_fdb.c,v 1.6 2002/01/17 00:57:07 davem Exp $
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.
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 <linux/random.h>
24 #include <asm/atomic.h>
25 #include <asm/unaligned.h>
26 #include "br_private.h"
28 static struct kmem_cache *br_fdb_cache __read_mostly;
29 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
30 const unsigned char *addr);
32 static u32 fdb_salt __read_mostly;
34 int __init br_fdb_init(void)
36 br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
37 sizeof(struct net_bridge_fdb_entry),
39 SLAB_HWCACHE_ALIGN, NULL);
40 if (!br_fdb_cache)
41 return -ENOMEM;
43 get_random_bytes(&fdb_salt, sizeof(fdb_salt));
44 return 0;
47 void __exit br_fdb_fini(void)
49 kmem_cache_destroy(br_fdb_cache);
53 /* if topology_changing then use forward_delay (default 15 sec)
54 * otherwise keep longer (default 5 minutes)
56 static inline unsigned long hold_time(const struct net_bridge *br)
58 return br->topology_change ? br->forward_delay : br->ageing_time;
61 static inline int has_expired(const struct net_bridge *br,
62 const struct net_bridge_fdb_entry *fdb)
64 return !fdb->is_static
65 && time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
68 static inline int br_mac_hash(const unsigned char *mac)
70 /* 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);
75 static inline void fdb_delete(struct net_bridge_fdb_entry *f)
77 hlist_del_rcu(&f->hlist);
78 br_fdb_put(f);
81 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
83 struct net_bridge *br = p->br;
84 int i;
86 spin_lock_bh(&br->hash_lock);
88 /* Search all chains since old address/hash is unknown */
89 for (i = 0; i < BR_HASH_SIZE; i++) {
90 struct hlist_node *h;
91 hlist_for_each(h, &br->hash[i]) {
92 struct net_bridge_fdb_entry *f;
94 f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
95 if (f->dst == p && f->is_local) {
96 /* maybe another port has same hw addr? */
97 struct net_bridge_port *op;
98 list_for_each_entry(op, &br->port_list, list) {
99 if (op != p &&
100 !compare_ether_addr(op->dev->dev_addr,
101 f->addr.addr)) {
102 f->dst = op;
103 goto insert;
107 /* delete old one */
108 fdb_delete(f);
109 goto insert;
113 insert:
114 /* insert new address, may fail if invalid address or dup. */
115 fdb_insert(br, p, newaddr);
117 spin_unlock_bh(&br->hash_lock);
120 void br_fdb_cleanup(unsigned long _data)
122 struct net_bridge *br = (struct net_bridge *)_data;
123 unsigned long delay = hold_time(br);
124 unsigned long next_timer = jiffies + br->forward_delay;
125 int i;
127 spin_lock_bh(&br->hash_lock);
128 for (i = 0; i < BR_HASH_SIZE; i++) {
129 struct net_bridge_fdb_entry *f;
130 struct hlist_node *h, *n;
132 hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
133 unsigned long this_timer;
134 if (f->is_static)
135 continue;
136 this_timer = f->ageing_timer + delay;
137 if (time_before_eq(this_timer, jiffies))
138 fdb_delete(f);
139 else if (this_timer < next_timer)
140 next_timer = this_timer;
143 spin_unlock_bh(&br->hash_lock);
145 /* Add HZ/4 to ensure we round the jiffies upwards to be after the next
146 * timer, otherwise we might round down and will have no-op run. */
147 mod_timer(&br->gc_timer, round_jiffies(next_timer + HZ/4));
150 /* Completely flush all dynamic entries in forwarding database.*/
151 void br_fdb_flush(struct net_bridge *br)
153 int i;
155 spin_lock_bh(&br->hash_lock);
156 for (i = 0; i < BR_HASH_SIZE; i++) {
157 struct net_bridge_fdb_entry *f;
158 struct hlist_node *h, *n;
159 hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
160 if (!f->is_static)
161 fdb_delete(f);
164 spin_unlock_bh(&br->hash_lock);
167 /* Flush all entries refering to a specific port.
168 * if do_all is set also flush static entries
170 void br_fdb_delete_by_port(struct net_bridge *br,
171 const struct net_bridge_port *p,
172 int do_all)
174 int i;
176 spin_lock_bh(&br->hash_lock);
177 for (i = 0; i < BR_HASH_SIZE; i++) {
178 struct hlist_node *h, *g;
180 hlist_for_each_safe(h, g, &br->hash[i]) {
181 struct net_bridge_fdb_entry *f
182 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
183 if (f->dst != p)
184 continue;
186 if (f->is_static && !do_all)
187 continue;
189 * if multiple ports all have the same device address
190 * then when one port is deleted, assign
191 * the local entry to other port
193 if (f->is_local) {
194 struct net_bridge_port *op;
195 list_for_each_entry(op, &br->port_list, list) {
196 if (op != p &&
197 !compare_ether_addr(op->dev->dev_addr,
198 f->addr.addr)) {
199 f->dst = op;
200 goto skip_delete;
205 fdb_delete(f);
206 skip_delete: ;
209 spin_unlock_bh(&br->hash_lock);
212 /* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
213 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
214 const unsigned char *addr)
216 struct hlist_node *h;
217 struct net_bridge_fdb_entry *fdb;
219 hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
220 if (!compare_ether_addr(fdb->addr.addr, addr)) {
221 if (unlikely(has_expired(br, fdb)))
222 break;
223 return fdb;
227 return NULL;
230 /* Interface used by ATM hook that keeps a ref count */
231 struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br,
232 unsigned char *addr)
234 struct net_bridge_fdb_entry *fdb;
236 rcu_read_lock();
237 fdb = __br_fdb_get(br, addr);
238 if (fdb && !atomic_inc_not_zero(&fdb->use_count))
239 fdb = NULL;
240 rcu_read_unlock();
241 return fdb;
244 static void fdb_rcu_free(struct rcu_head *head)
246 struct net_bridge_fdb_entry *ent
247 = container_of(head, struct net_bridge_fdb_entry, rcu);
248 kmem_cache_free(br_fdb_cache, ent);
251 /* Set entry up for deletion with RCU */
252 void br_fdb_put(struct net_bridge_fdb_entry *ent)
254 if (atomic_dec_and_test(&ent->use_count))
255 call_rcu(&ent->rcu, fdb_rcu_free);
259 * Fill buffer with forwarding table records in
260 * the API format.
262 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
263 unsigned long maxnum, unsigned long skip)
265 struct __fdb_entry *fe = buf;
266 int i, num = 0;
267 struct hlist_node *h;
268 struct net_bridge_fdb_entry *f;
270 memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
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;
278 if (has_expired(br, f))
279 continue;
281 if (skip) {
282 --skip;
283 continue;
286 /* convert from internal format to API */
287 memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
288 fe->port_no = f->dst->port_no;
289 fe->is_local = f->is_local;
290 if (!f->is_static)
291 fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer);
292 ++fe;
293 ++num;
297 out:
298 rcu_read_unlock();
300 return num;
303 static inline struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
304 const unsigned char *addr)
306 struct hlist_node *h;
307 struct net_bridge_fdb_entry *fdb;
309 hlist_for_each_entry_rcu(fdb, h, head, hlist) {
310 if (!compare_ether_addr(fdb->addr.addr, addr))
311 return fdb;
313 return NULL;
316 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
317 struct net_bridge_port *source,
318 const unsigned char *addr,
319 int is_local)
321 struct net_bridge_fdb_entry *fdb;
323 fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
324 if (fdb) {
325 memcpy(fdb->addr.addr, addr, ETH_ALEN);
326 atomic_set(&fdb->use_count, 1);
327 hlist_add_head_rcu(&fdb->hlist, head);
329 fdb->dst = source;
330 fdb->is_local = is_local;
331 fdb->is_static = is_local;
332 fdb->ageing_timer = jiffies;
334 return fdb;
337 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
338 const unsigned char *addr)
340 struct hlist_head *head = &br->hash[br_mac_hash(addr)];
341 struct net_bridge_fdb_entry *fdb;
343 if (!is_valid_ether_addr(addr))
344 return -EINVAL;
346 fdb = fdb_find(head, addr);
347 if (fdb) {
348 /* it is okay to have multiple ports with same
349 * address, just use the first one.
351 if (fdb->is_local)
352 return 0;
354 printk(KERN_WARNING "%s adding interface with same address "
355 "as a received packet\n",
356 source->dev->name);
357 fdb_delete(fdb);
360 if (!fdb_create(head, source, addr, 1))
361 return -ENOMEM;
363 return 0;
366 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
367 const unsigned char *addr)
369 int ret;
371 spin_lock_bh(&br->hash_lock);
372 ret = fdb_insert(br, source, addr);
373 spin_unlock_bh(&br->hash_lock);
374 return ret;
377 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
378 const unsigned char *addr)
380 struct hlist_head *head = &br->hash[br_mac_hash(addr)];
381 struct net_bridge_fdb_entry *fdb;
383 /* some users want to always flood. */
384 if (hold_time(br) == 0)
385 return;
387 fdb = fdb_find(head, addr);
388 if (likely(fdb)) {
389 /* attempt to update an entry for a local interface */
390 if (unlikely(fdb->is_local)) {
391 if (net_ratelimit())
392 printk(KERN_WARNING "%s: received packet with "
393 " own address as source address\n",
394 source->dev->name);
395 } else {
396 /* fastpath: update of existing entry */
397 fdb->dst = source;
398 fdb->ageing_timer = jiffies;
400 } else {
401 spin_lock(&br->hash_lock);
402 if (!fdb_find(head, addr))
403 fdb_create(head, source, addr, 0);
404 /* else we lose race and someone else inserts
405 * it first, don't bother updating
407 spin_unlock(&br->hash_lock);