Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
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> | |
3f890923 | 23 | #include <linux/random.h> |
1da177e4 | 24 | #include <asm/atomic.h> |
3f890923 | 25 | #include <asm/unaligned.h> |
1da177e4 LT |
26 | #include "br_private.h" |
27 | ||
e18b890b | 28 | static struct kmem_cache *br_fdb_cache __read_mostly; |
1da177e4 LT |
29 | static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source, |
30 | const unsigned char *addr); | |
31 | ||
3f890923 SH |
32 | static u32 fdb_salt __read_mostly; |
33 | ||
87a596e0 | 34 | int __init br_fdb_init(void) |
1da177e4 LT |
35 | { |
36 | br_fdb_cache = kmem_cache_create("bridge_fdb_cache", | |
37 | sizeof(struct net_bridge_fdb_entry), | |
38 | 0, | |
20c2df83 | 39 | SLAB_HWCACHE_ALIGN, NULL); |
87a596e0 AM |
40 | if (!br_fdb_cache) |
41 | return -ENOMEM; | |
42 | ||
3f890923 | 43 | get_random_bytes(&fdb_salt, sizeof(fdb_salt)); |
87a596e0 | 44 | return 0; |
1da177e4 LT |
45 | } |
46 | ||
47 | void __exit br_fdb_fini(void) | |
48 | { | |
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 | */ | |
3f890923 | 56 | static inline unsigned long hold_time(const struct net_bridge *br) |
1da177e4 LT |
57 | { |
58 | return br->topology_change ? br->forward_delay : br->ageing_time; | |
59 | } | |
60 | ||
3f890923 | 61 | static inline int has_expired(const struct net_bridge *br, |
1da177e4 LT |
62 | const struct net_bridge_fdb_entry *fdb) |
63 | { | |
9d6f229f | 64 | return !fdb->is_static |
1da177e4 LT |
65 | && time_before_eq(fdb->ageing_timer + hold_time(br), jiffies); |
66 | } | |
67 | ||
3f890923 | 68 | static inline int br_mac_hash(const unsigned char *mac) |
1da177e4 | 69 | { |
3f890923 SH |
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); | |
1da177e4 LT |
73 | } |
74 | ||
3f890923 | 75 | static inline void fdb_delete(struct net_bridge_fdb_entry *f) |
1da177e4 LT |
76 | { |
77 | hlist_del_rcu(&f->hlist); | |
78 | br_fdb_put(f); | |
79 | } | |
80 | ||
81 | void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr) | |
82 | { | |
83 | struct net_bridge *br = p->br; | |
84 | int i; | |
9d6f229f | 85 | |
1da177e4 LT |
86 | spin_lock_bh(&br->hash_lock); |
87 | ||
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; | |
93 | ||
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) { | |
9d6f229f | 99 | if (op != p && |
6ede2463 SH |
100 | !compare_ether_addr(op->dev->dev_addr, |
101 | f->addr.addr)) { | |
1da177e4 LT |
102 | f->dst = op; |
103 | goto insert; | |
104 | } | |
105 | } | |
106 | ||
107 | /* delete old one */ | |
108 | fdb_delete(f); | |
109 | goto insert; | |
110 | } | |
111 | } | |
112 | } | |
113 | insert: | |
114 | /* insert new address, may fail if invalid address or dup. */ | |
115 | fdb_insert(br, p, newaddr); | |
116 | ||
117 | spin_unlock_bh(&br->hash_lock); | |
118 | } | |
119 | ||
120 | void br_fdb_cleanup(unsigned long _data) | |
121 | { | |
122 | struct net_bridge *br = (struct net_bridge *)_data; | |
123 | unsigned long delay = hold_time(br); | |
071f7722 | 124 | unsigned long next_timer = jiffies + br->forward_delay; |
1da177e4 LT |
125 | int i; |
126 | ||
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; | |
131 | ||
132 | hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) { | |
071f7722 BE |
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)) | |
1da177e4 | 138 | fdb_delete(f); |
071f7722 BE |
139 | else if (this_timer < next_timer) |
140 | next_timer = this_timer; | |
1da177e4 LT |
141 | } |
142 | } | |
143 | spin_unlock_bh(&br->hash_lock); | |
144 | ||
071f7722 BE |
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)); | |
1da177e4 LT |
148 | } |
149 | ||
9cf63747 SH |
150 | /* Completely flush all dynamic entries in forwarding database.*/ |
151 | void br_fdb_flush(struct net_bridge *br) | |
152 | { | |
153 | int i; | |
154 | ||
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); | |
162 | } | |
163 | } | |
164 | spin_unlock_bh(&br->hash_lock); | |
165 | } | |
1a620698 | 166 | |
9cf63747 SH |
167 | /* Flush all entries refering to a specific port. |
168 | * if do_all is set also flush static entries | |
169 | */ | |
1a620698 SH |
170 | void br_fdb_delete_by_port(struct net_bridge *br, |
171 | const struct net_bridge_port *p, | |
172 | int do_all) | |
1da177e4 LT |
173 | { |
174 | int i; | |
175 | ||
176 | spin_lock_bh(&br->hash_lock); | |
177 | for (i = 0; i < BR_HASH_SIZE; i++) { | |
178 | struct hlist_node *h, *g; | |
9d6f229f | 179 | |
1da177e4 LT |
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); | |
9d6f229f | 183 | if (f->dst != p) |
1da177e4 LT |
184 | continue; |
185 | ||
1a620698 SH |
186 | if (f->is_static && !do_all) |
187 | continue; | |
1da177e4 LT |
188 | /* |
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 | |
192 | */ | |
193 | if (f->is_local) { | |
194 | struct net_bridge_port *op; | |
195 | list_for_each_entry(op, &br->port_list, list) { | |
9d6f229f | 196 | if (op != p && |
6ede2463 SH |
197 | !compare_ether_addr(op->dev->dev_addr, |
198 | f->addr.addr)) { | |
1da177e4 LT |
199 | f->dst = op; |
200 | goto skip_delete; | |
201 | } | |
202 | } | |
203 | } | |
204 | ||
205 | fdb_delete(f); | |
206 | skip_delete: ; | |
207 | } | |
208 | } | |
209 | spin_unlock_bh(&br->hash_lock); | |
210 | } | |
211 | ||
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) | |
215 | { | |
216 | struct hlist_node *h; | |
217 | struct net_bridge_fdb_entry *fdb; | |
218 | ||
219 | hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) { | |
6ede2463 | 220 | if (!compare_ether_addr(fdb->addr.addr, addr)) { |
1da177e4 LT |
221 | if (unlikely(has_expired(br, fdb))) |
222 | break; | |
223 | return fdb; | |
224 | } | |
225 | } | |
226 | ||
227 | return NULL; | |
228 | } | |
229 | ||
230 | /* Interface used by ATM hook that keeps a ref count */ | |
9d6f229f | 231 | struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br, |
1da177e4 LT |
232 | unsigned char *addr) |
233 | { | |
234 | struct net_bridge_fdb_entry *fdb; | |
235 | ||
236 | rcu_read_lock(); | |
237 | fdb = __br_fdb_get(br, addr); | |
b19cbe2a PM |
238 | if (fdb && !atomic_inc_not_zero(&fdb->use_count)) |
239 | fdb = NULL; | |
1da177e4 LT |
240 | rcu_read_unlock(); |
241 | return fdb; | |
242 | } | |
243 | ||
244 | static void fdb_rcu_free(struct rcu_head *head) | |
245 | { | |
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); | |
249 | } | |
250 | ||
251 | /* Set entry up for deletion with RCU */ | |
252 | void br_fdb_put(struct net_bridge_fdb_entry *ent) | |
253 | { | |
254 | if (atomic_dec_and_test(&ent->use_count)) | |
255 | call_rcu(&ent->rcu, fdb_rcu_free); | |
256 | } | |
257 | ||
258 | /* | |
9d6f229f | 259 | * Fill buffer with forwarding table records in |
1da177e4 LT |
260 | * the API format. |
261 | */ | |
262 | int 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 | ||
9d6f229f | 278 | if (has_expired(br, f)) |
1da177e4 LT |
279 | 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); | |
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; | |
294 | } | |
295 | } | |
296 | ||
297 | out: | |
298 | rcu_read_unlock(); | |
299 | ||
300 | return num; | |
301 | } | |
302 | ||
303 | static inline struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head, | |
304 | const unsigned char *addr) | |
305 | { | |
306 | struct hlist_node *h; | |
307 | struct net_bridge_fdb_entry *fdb; | |
308 | ||
309 | hlist_for_each_entry_rcu(fdb, h, head, hlist) { | |
6ede2463 | 310 | if (!compare_ether_addr(fdb->addr.addr, addr)) |
1da177e4 LT |
311 | return fdb; |
312 | } | |
313 | return NULL; | |
314 | } | |
315 | ||
316 | static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head, | |
317 | struct net_bridge_port *source, | |
9d6f229f | 318 | const unsigned char *addr, |
1da177e4 LT |
319 | int is_local) |
320 | { | |
321 | struct net_bridge_fdb_entry *fdb; | |
322 | ||
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); | |
328 | ||
329 | fdb->dst = source; | |
330 | fdb->is_local = is_local; | |
331 | fdb->is_static = is_local; | |
332 | fdb->ageing_timer = jiffies; | |
333 | } | |
334 | return fdb; | |
335 | } | |
336 | ||
337 | static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source, | |
338 | const unsigned char *addr) | |
339 | { | |
340 | struct hlist_head *head = &br->hash[br_mac_hash(addr)]; | |
341 | struct net_bridge_fdb_entry *fdb; | |
342 | ||
343 | if (!is_valid_ether_addr(addr)) | |
344 | return -EINVAL; | |
345 | ||
346 | fdb = fdb_find(head, addr); | |
347 | if (fdb) { | |
9d6f229f | 348 | /* it is okay to have multiple ports with same |
1da177e4 LT |
349 | * address, just use the first one. |
350 | */ | |
9d6f229f | 351 | if (fdb->is_local) |
1da177e4 LT |
352 | return 0; |
353 | ||
354 | printk(KERN_WARNING "%s adding interface with same address " | |
355 | "as a received packet\n", | |
356 | source->dev->name); | |
357 | fdb_delete(fdb); | |
9d6f229f | 358 | } |
1da177e4 LT |
359 | |
360 | if (!fdb_create(head, source, addr, 1)) | |
361 | return -ENOMEM; | |
362 | ||
363 | return 0; | |
364 | } | |
365 | ||
366 | int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source, | |
367 | const unsigned char *addr) | |
368 | { | |
369 | int ret; | |
370 | ||
371 | spin_lock_bh(&br->hash_lock); | |
372 | ret = fdb_insert(br, source, addr); | |
373 | spin_unlock_bh(&br->hash_lock); | |
374 | return ret; | |
375 | } | |
376 | ||
377 | void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source, | |
378 | const unsigned char *addr) | |
379 | { | |
380 | struct hlist_head *head = &br->hash[br_mac_hash(addr)]; | |
381 | struct net_bridge_fdb_entry *fdb; | |
382 | ||
383 | /* some users want to always flood. */ | |
384 | if (hold_time(br) == 0) | |
385 | return; | |
386 | ||
1da177e4 LT |
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)) { | |
9d6f229f | 391 | if (net_ratelimit()) |
1da177e4 LT |
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; | |
399 | } | |
400 | } else { | |
f8ae737d | 401 | spin_lock(&br->hash_lock); |
1da177e4 LT |
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 | |
406 | */ | |
f8ae737d | 407 | spin_unlock(&br->hash_lock); |
1da177e4 | 408 | } |
1da177e4 | 409 | } |