1 /*
2 * Forwarding database
3 * Linux ethernet bridge
4 *
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
7 *
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.
12 */
13
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 <linux/slab.h>
24 #include <linux/atomic.h>
25 #include <asm/unaligned.h>
26 #include <linux/if_vlan.h>
27 #include "br_private.h"
28
29 static struct kmem_cache *br_fdb_cache __read_mostly;
30 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
31 const unsigned char *addr,
32 __u16 vid);
33 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
34 const unsigned char *addr, u16 vid);
35 static void fdb_notify(struct net_bridge *br,
36 const struct net_bridge_fdb_entry *, int);
37
38 static u32 fdb_salt __read_mostly;
39
br_fdb_init(void)40 int __init br_fdb_init(void)
41 {
42 br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
43 sizeof(struct net_bridge_fdb_entry),
44 0,
45 SLAB_HWCACHE_ALIGN, NULL);
46 if (!br_fdb_cache)
47 return -ENOMEM;
48
49 get_random_bytes(&fdb_salt, sizeof(fdb_salt));
50 return 0;
51 }
52
br_fdb_fini(void)53 void br_fdb_fini(void)
54 {
55 kmem_cache_destroy(br_fdb_cache);
56 }
57
58
59 /* if topology_changing then use forward_delay (default 15 sec)
60 * otherwise keep longer (default 5 minutes)
61 */
hold_time(const struct net_bridge * br)62 static inline unsigned long hold_time(const struct net_bridge *br)
63 {
64 return br->topology_change ? br->forward_delay : br->ageing_time;
65 }
66
has_expired(const struct net_bridge * br,const struct net_bridge_fdb_entry * fdb)67 static inline int has_expired(const struct net_bridge *br,
68 const struct net_bridge_fdb_entry *fdb)
69 {
70 return !fdb->is_static &&
71 time_before_eq(fdb->updated + hold_time(br), jiffies);
72 }
73
br_mac_hash(const unsigned char * mac,__u16 vid)74 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
75 {
76 /* use 1 byte of OUI and 3 bytes of NIC */
77 u32 key = get_unaligned((u32 *)(mac + 2));
78 return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
79 }
80
fdb_rcu_free(struct rcu_head * head)81 static void fdb_rcu_free(struct rcu_head *head)
82 {
83 struct net_bridge_fdb_entry *ent
84 = container_of(head, struct net_bridge_fdb_entry, rcu);
85 kmem_cache_free(br_fdb_cache, ent);
86 }
87
88 /* When a static FDB entry is added, the mac address from the entry is
89 * added to the bridge private HW address list and all required ports
90 * are then updated with the new information.
91 * Called under RTNL.
92 */
fdb_add_hw(struct net_bridge * br,const unsigned char * addr)93 static void fdb_add_hw(struct net_bridge *br, const unsigned char *addr)
94 {
95 int err;
96 struct net_bridge_port *p;
97
98 ASSERT_RTNL();
99
100 list_for_each_entry(p, &br->port_list, list) {
101 if (!br_promisc_port(p)) {
102 err = dev_uc_add(p->dev, addr);
103 if (err)
104 goto undo;
105 }
106 }
107
108 return;
109 undo:
110 list_for_each_entry_continue_reverse(p, &br->port_list, list) {
111 if (!br_promisc_port(p))
112 dev_uc_del(p->dev, addr);
113 }
114 }
115
116 /* When a static FDB entry is deleted, the HW address from that entry is
117 * also removed from the bridge private HW address list and updates all
118 * the ports with needed information.
119 * Called under RTNL.
120 */
fdb_del_hw(struct net_bridge * br,const unsigned char * addr)121 static void fdb_del_hw(struct net_bridge *br, const unsigned char *addr)
122 {
123 struct net_bridge_port *p;
124
125 ASSERT_RTNL();
126
127 list_for_each_entry(p, &br->port_list, list) {
128 if (!br_promisc_port(p))
129 dev_uc_del(p->dev, addr);
130 }
131 }
132
fdb_delete(struct net_bridge * br,struct net_bridge_fdb_entry * f)133 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
134 {
135 if (f->is_static)
136 fdb_del_hw(br, f->addr.addr);
137
138 hlist_del_rcu(&f->hlist);
139 fdb_notify(br, f, RTM_DELNEIGH);
140 call_rcu(&f->rcu, fdb_rcu_free);
141 }
142
143 /* Delete a local entry if no other port had the same address. */
fdb_delete_local(struct net_bridge * br,const struct net_bridge_port * p,struct net_bridge_fdb_entry * f)144 static void fdb_delete_local(struct net_bridge *br,
145 const struct net_bridge_port *p,
146 struct net_bridge_fdb_entry *f)
147 {
148 const unsigned char *addr = f->addr.addr;
149 u16 vid = f->vlan_id;
150 struct net_bridge_port *op;
151
152 /* Maybe another port has same hw addr? */
153 list_for_each_entry(op, &br->port_list, list) {
154 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
155 (!vid || nbp_vlan_find(op, vid))) {
156 f->dst = op;
157 f->added_by_user = 0;
158 return;
159 }
160 }
161
162 /* Maybe bridge device has same hw addr? */
163 if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
164 (!vid || br_vlan_find(br, vid))) {
165 f->dst = NULL;
166 f->added_by_user = 0;
167 return;
168 }
169
170 fdb_delete(br, f);
171 }
172
br_fdb_find_delete_local(struct net_bridge * br,const struct net_bridge_port * p,const unsigned char * addr,u16 vid)173 void br_fdb_find_delete_local(struct net_bridge *br,
174 const struct net_bridge_port *p,
175 const unsigned char *addr, u16 vid)
176 {
177 struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
178 struct net_bridge_fdb_entry *f;
179
180 spin_lock_bh(&br->hash_lock);
181 f = fdb_find(head, addr, vid);
182 if (f && f->is_local && !f->added_by_user && f->dst == p)
183 fdb_delete_local(br, p, f);
184 spin_unlock_bh(&br->hash_lock);
185 }
186
br_fdb_changeaddr(struct net_bridge_port * p,const unsigned char * newaddr)187 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
188 {
189 struct net_bridge *br = p->br;
190 struct net_port_vlans *pv = nbp_get_vlan_info(p);
191 bool no_vlan = !pv;
192 int i;
193 u16 vid;
194
195 spin_lock_bh(&br->hash_lock);
196
197 /* Search all chains since old address/hash is unknown */
198 for (i = 0; i < BR_HASH_SIZE; i++) {
199 struct hlist_node *h;
200 hlist_for_each(h, &br->hash[i]) {
201 struct net_bridge_fdb_entry *f;
202
203 f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
204 if (f->dst == p && f->is_local && !f->added_by_user) {
205 /* delete old one */
206 fdb_delete_local(br, p, f);
207
208 /* if this port has no vlan information
209 * configured, we can safely be done at
210 * this point.
211 */
212 if (no_vlan)
213 goto insert;
214 }
215 }
216 }
217
218 insert:
219 /* insert new address, may fail if invalid address or dup. */
220 fdb_insert(br, p, newaddr, 0);
221
222 if (no_vlan)
223 goto done;
224
225 /* Now add entries for every VLAN configured on the port.
226 * This function runs under RTNL so the bitmap will not change
227 * from under us.
228 */
229 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
230 fdb_insert(br, p, newaddr, vid);
231
232 done:
233 spin_unlock_bh(&br->hash_lock);
234 }
235
br_fdb_change_mac_address(struct net_bridge * br,const u8 * newaddr)236 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
237 {
238 struct net_bridge_fdb_entry *f;
239 struct net_port_vlans *pv;
240 u16 vid = 0;
241
242 spin_lock_bh(&br->hash_lock);
243
244 /* If old entry was unassociated with any port, then delete it. */
245 f = __br_fdb_get(br, br->dev->dev_addr, 0);
246 if (f && f->is_local && !f->dst)
247 fdb_delete_local(br, NULL, f);
248
249 fdb_insert(br, NULL, newaddr, 0);
250
251 /* Now remove and add entries for every VLAN configured on the
252 * bridge. This function runs under RTNL so the bitmap will not
253 * change from under us.
254 */
255 pv = br_get_vlan_info(br);
256 if (!pv)
257 goto out;
258
259 for_each_set_bit_from(vid, pv->vlan_bitmap, VLAN_N_VID) {
260 f = __br_fdb_get(br, br->dev->dev_addr, vid);
261 if (f && f->is_local && !f->dst)
262 fdb_delete_local(br, NULL, f);
263 fdb_insert(br, NULL, newaddr, vid);
264 }
265 out:
266 spin_unlock_bh(&br->hash_lock);
267 }
268
br_fdb_cleanup(unsigned long _data)269 void br_fdb_cleanup(unsigned long _data)
270 {
271 struct net_bridge *br = (struct net_bridge *)_data;
272 unsigned long delay = hold_time(br);
273 unsigned long next_timer = jiffies + br->ageing_time;
274 int i;
275
276 spin_lock(&br->hash_lock);
277 for (i = 0; i < BR_HASH_SIZE; i++) {
278 struct net_bridge_fdb_entry *f;
279 struct hlist_node *n;
280
281 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
282 unsigned long this_timer;
283 if (f->is_static)
284 continue;
285 this_timer = f->updated + delay;
286 if (time_before_eq(this_timer, jiffies))
287 fdb_delete(br, f);
288 else if (time_before(this_timer, next_timer))
289 next_timer = this_timer;
290 }
291 }
292 spin_unlock(&br->hash_lock);
293
294 mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
295 }
296
297 /* Completely flush all dynamic entries in forwarding database.*/
br_fdb_flush(struct net_bridge * br)298 void br_fdb_flush(struct net_bridge *br)
299 {
300 int i;
301
302 spin_lock_bh(&br->hash_lock);
303 for (i = 0; i < BR_HASH_SIZE; i++) {
304 struct net_bridge_fdb_entry *f;
305 struct hlist_node *n;
306 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
307 if (!f->is_static)
308 fdb_delete(br, f);
309 }
310 }
311 spin_unlock_bh(&br->hash_lock);
312 }
313
314 /* Flush all entries referring to a specific port.
315 * if do_all is set also flush static entries
316 */
br_fdb_delete_by_port(struct net_bridge * br,const struct net_bridge_port * p,int do_all)317 void br_fdb_delete_by_port(struct net_bridge *br,
318 const struct net_bridge_port *p,
319 int do_all)
320 {
321 int i;
322
323 spin_lock_bh(&br->hash_lock);
324 for (i = 0; i < BR_HASH_SIZE; i++) {
325 struct hlist_node *h, *g;
326
327 hlist_for_each_safe(h, g, &br->hash[i]) {
328 struct net_bridge_fdb_entry *f
329 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
330 if (f->dst != p)
331 continue;
332
333 if (f->is_static && !do_all)
334 continue;
335
336 if (f->is_local)
337 fdb_delete_local(br, p, f);
338 else
339 fdb_delete(br, f);
340 }
341 }
342 spin_unlock_bh(&br->hash_lock);
343 }
344
345 /* No locking or refcounting, assumes caller has rcu_read_lock */
__br_fdb_get(struct net_bridge * br,const unsigned char * addr,__u16 vid)346 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
347 const unsigned char *addr,
348 __u16 vid)
349 {
350 struct net_bridge_fdb_entry *fdb;
351
352 hlist_for_each_entry_rcu(fdb,
353 &br->hash[br_mac_hash(addr, vid)], hlist) {
354 if (ether_addr_equal(fdb->addr.addr, addr) &&
355 fdb->vlan_id == vid) {
356 if (unlikely(has_expired(br, fdb)))
357 break;
358 return fdb;
359 }
360 }
361
362 return NULL;
363 }
364
365 #if IS_ENABLED(CONFIG_ATM_LANE)
366 /* Interface used by ATM LANE hook to test
367 * if an addr is on some other bridge port */
br_fdb_test_addr(struct net_device * dev,unsigned char * addr)368 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
369 {
370 struct net_bridge_fdb_entry *fdb;
371 struct net_bridge_port *port;
372 int ret;
373
374 rcu_read_lock();
375 port = br_port_get_rcu(dev);
376 if (!port)
377 ret = 0;
378 else {
379 fdb = __br_fdb_get(port->br, addr, 0);
380 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
381 fdb->dst->state == BR_STATE_FORWARDING;
382 }
383 rcu_read_unlock();
384
385 return ret;
386 }
387 #endif /* CONFIG_ATM_LANE */
388
389 /*
390 * Fill buffer with forwarding table records in
391 * the API format.
392 */
br_fdb_fillbuf(struct net_bridge * br,void * buf,unsigned long maxnum,unsigned long skip)393 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
394 unsigned long maxnum, unsigned long skip)
395 {
396 struct __fdb_entry *fe = buf;
397 int i, num = 0;
398 struct net_bridge_fdb_entry *f;
399
400 memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
401
402 rcu_read_lock();
403 for (i = 0; i < BR_HASH_SIZE; i++) {
404 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
405 if (num >= maxnum)
406 goto out;
407
408 if (has_expired(br, f))
409 continue;
410
411 /* ignore pseudo entry for local MAC address */
412 if (!f->dst)
413 continue;
414
415 if (skip) {
416 --skip;
417 continue;
418 }
419
420 /* convert from internal format to API */
421 memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
422
423 /* due to ABI compat need to split into hi/lo */
424 fe->port_no = f->dst->port_no;
425 fe->port_hi = f->dst->port_no >> 8;
426
427 fe->is_local = f->is_local;
428 if (!f->is_static)
429 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
430 ++fe;
431 ++num;
432 }
433 }
434
435 out:
436 rcu_read_unlock();
437
438 return num;
439 }
440
fdb_find(struct hlist_head * head,const unsigned char * addr,__u16 vid)441 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
442 const unsigned char *addr,
443 __u16 vid)
444 {
445 struct net_bridge_fdb_entry *fdb;
446
447 hlist_for_each_entry(fdb, head, hlist) {
448 if (ether_addr_equal(fdb->addr.addr, addr) &&
449 fdb->vlan_id == vid)
450 return fdb;
451 }
452 return NULL;
453 }
454
fdb_find_rcu(struct hlist_head * head,const unsigned char * addr,__u16 vid)455 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
456 const unsigned char *addr,
457 __u16 vid)
458 {
459 struct net_bridge_fdb_entry *fdb;
460
461 hlist_for_each_entry_rcu(fdb, head, hlist) {
462 if (ether_addr_equal(fdb->addr.addr, addr) &&
463 fdb->vlan_id == vid)
464 return fdb;
465 }
466 return NULL;
467 }
468
fdb_create(struct hlist_head * head,struct net_bridge_port * source,const unsigned char * addr,__u16 vid)469 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
470 struct net_bridge_port *source,
471 const unsigned char *addr,
472 __u16 vid)
473 {
474 struct net_bridge_fdb_entry *fdb;
475
476 fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
477 if (fdb) {
478 memcpy(fdb->addr.addr, addr, ETH_ALEN);
479 fdb->dst = source;
480 fdb->vlan_id = vid;
481 fdb->is_local = 0;
482 fdb->is_static = 0;
483 fdb->added_by_user = 0;
484 fdb->updated = fdb->used = jiffies;
485 hlist_add_head_rcu(&fdb->hlist, head);
486 }
487 return fdb;
488 }
489
fdb_insert(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid)490 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
491 const unsigned char *addr, u16 vid)
492 {
493 struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
494 struct net_bridge_fdb_entry *fdb;
495
496 if (!is_valid_ether_addr(addr))
497 return -EINVAL;
498
499 fdb = fdb_find(head, addr, vid);
500 if (fdb) {
501 /* it is okay to have multiple ports with same
502 * address, just use the first one.
503 */
504 if (fdb->is_local)
505 return 0;
506 br_warn(br, "adding interface %s with same address "
507 "as a received packet\n",
508 source ? source->dev->name : br->dev->name);
509 fdb_delete(br, fdb);
510 }
511
512 fdb = fdb_create(head, source, addr, vid);
513 if (!fdb)
514 return -ENOMEM;
515
516 fdb->is_local = fdb->is_static = 1;
517 fdb_add_hw(br, addr);
518 fdb_notify(br, fdb, RTM_NEWNEIGH);
519 return 0;
520 }
521
522 /* Add entry for local address of interface */
br_fdb_insert(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid)523 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
524 const unsigned char *addr, u16 vid)
525 {
526 int ret;
527
528 spin_lock_bh(&br->hash_lock);
529 ret = fdb_insert(br, source, addr, vid);
530 spin_unlock_bh(&br->hash_lock);
531 return ret;
532 }
533
br_fdb_update(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid,bool added_by_user)534 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
535 const unsigned char *addr, u16 vid, bool added_by_user)
536 {
537 struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
538 struct net_bridge_fdb_entry *fdb;
539 bool fdb_modified = false;
540
541 /* some users want to always flood. */
542 if (hold_time(br) == 0)
543 return;
544
545 /* ignore packets unless we are using this port */
546 if (!(source->state == BR_STATE_LEARNING ||
547 source->state == BR_STATE_FORWARDING))
548 return;
549
550 fdb = fdb_find_rcu(head, addr, vid);
551 if (likely(fdb)) {
552 /* attempt to update an entry for a local interface */
553 if (unlikely(fdb->is_local)) {
554 if (net_ratelimit())
555 br_warn(br, "received packet on %s with "
556 "own address as source address\n",
557 source->dev->name);
558 } else {
559 /* fastpath: update of existing entry */
560 if (unlikely(source != fdb->dst)) {
561 fdb->dst = source;
562 fdb_modified = true;
563 }
564 fdb->updated = jiffies;
565 if (unlikely(added_by_user))
566 fdb->added_by_user = 1;
567 if (unlikely(fdb_modified))
568 fdb_notify(br, fdb, RTM_NEWNEIGH);
569 }
570 } else {
571 spin_lock(&br->hash_lock);
572 if (likely(!fdb_find(head, addr, vid))) {
573 fdb = fdb_create(head, source, addr, vid);
574 if (fdb) {
575 if (unlikely(added_by_user))
576 fdb->added_by_user = 1;
577 fdb_notify(br, fdb, RTM_NEWNEIGH);
578 }
579 }
580 /* else we lose race and someone else inserts
581 * it first, don't bother updating
582 */
583 spin_unlock(&br->hash_lock);
584 }
585 }
586
fdb_to_nud(const struct net_bridge_fdb_entry * fdb)587 static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
588 {
589 if (fdb->is_local)
590 return NUD_PERMANENT;
591 else if (fdb->is_static)
592 return NUD_NOARP;
593 else if (has_expired(fdb->dst->br, fdb))
594 return NUD_STALE;
595 else
596 return NUD_REACHABLE;
597 }
598
fdb_fill_info(struct sk_buff * skb,const struct net_bridge * br,const struct net_bridge_fdb_entry * fdb,u32 portid,u32 seq,int type,unsigned int flags)599 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
600 const struct net_bridge_fdb_entry *fdb,
601 u32 portid, u32 seq, int type, unsigned int flags)
602 {
603 unsigned long now = jiffies;
604 struct nda_cacheinfo ci;
605 struct nlmsghdr *nlh;
606 struct ndmsg *ndm;
607
608 nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
609 if (nlh == NULL)
610 return -EMSGSIZE;
611
612 ndm = nlmsg_data(nlh);
613 ndm->ndm_family = AF_BRIDGE;
614 ndm->ndm_pad1 = 0;
615 ndm->ndm_pad2 = 0;
616 ndm->ndm_flags = 0;
617 ndm->ndm_type = 0;
618 ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
619 ndm->ndm_state = fdb_to_nud(fdb);
620
621 if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
622 goto nla_put_failure;
623 if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
624 goto nla_put_failure;
625 ci.ndm_used = jiffies_to_clock_t(now - fdb->used);
626 ci.ndm_confirmed = 0;
627 ci.ndm_updated = jiffies_to_clock_t(now - fdb->updated);
628 ci.ndm_refcnt = 0;
629 if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
630 goto nla_put_failure;
631
632 if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
633 goto nla_put_failure;
634
635 return nlmsg_end(skb, nlh);
636
637 nla_put_failure:
638 nlmsg_cancel(skb, nlh);
639 return -EMSGSIZE;
640 }
641
fdb_nlmsg_size(void)642 static inline size_t fdb_nlmsg_size(void)
643 {
644 return NLMSG_ALIGN(sizeof(struct ndmsg))
645 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
646 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
647 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
648 + nla_total_size(sizeof(struct nda_cacheinfo));
649 }
650
fdb_notify(struct net_bridge * br,const struct net_bridge_fdb_entry * fdb,int type)651 static void fdb_notify(struct net_bridge *br,
652 const struct net_bridge_fdb_entry *fdb, int type)
653 {
654 struct net *net = dev_net(br->dev);
655 struct sk_buff *skb;
656 int err = -ENOBUFS;
657
658 skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
659 if (skb == NULL)
660 goto errout;
661
662 err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
663 if (err < 0) {
664 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
665 WARN_ON(err == -EMSGSIZE);
666 kfree_skb(skb);
667 goto errout;
668 }
669 rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
670 return;
671 errout:
672 rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
673 }
674
675 /* Dump information about entries, in response to GETNEIGH */
br_fdb_dump(struct sk_buff * skb,struct netlink_callback * cb,struct net_device * dev,struct net_device * filter_dev,int idx)676 int br_fdb_dump(struct sk_buff *skb,
677 struct netlink_callback *cb,
678 struct net_device *dev,
679 struct net_device *filter_dev,
680 int idx)
681 {
682 struct net_bridge *br = netdev_priv(dev);
683 int i;
684
685 if (!(dev->priv_flags & IFF_EBRIDGE))
686 goto out;
687
688 for (i = 0; i < BR_HASH_SIZE; i++) {
689 struct net_bridge_fdb_entry *f;
690
691 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
692 if (idx < cb->args[0])
693 goto skip;
694
695 if (filter_dev &&
696 (!f->dst || f->dst->dev != filter_dev)) {
697 if (filter_dev != dev)
698 goto skip;
699 /* !f->dst is a speacial case for bridge
700 * It means the MAC belongs to the bridge
701 * Therefore need a little more filtering
702 * we only want to dump the !f->dst case
703 */
704 if (f->dst)
705 goto skip;
706 }
707
708 if (fdb_fill_info(skb, br, f,
709 NETLINK_CB(cb->skb).portid,
710 cb->nlh->nlmsg_seq,
711 RTM_NEWNEIGH,
712 NLM_F_MULTI) < 0)
713 break;
714 skip:
715 ++idx;
716 }
717 }
718
719 out:
720 return idx;
721 }
722
723 /* Update (create or replace) forwarding database entry */
fdb_add_entry(struct net_bridge_port * source,const __u8 * addr,__u16 state,__u16 flags,__u16 vid)724 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
725 __u16 state, __u16 flags, __u16 vid)
726 {
727 struct net_bridge *br = source->br;
728 struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
729 struct net_bridge_fdb_entry *fdb;
730 bool modified = false;
731
732 fdb = fdb_find(head, addr, vid);
733 if (fdb == NULL) {
734 if (!(flags & NLM_F_CREATE))
735 return -ENOENT;
736
737 fdb = fdb_create(head, source, addr, vid);
738 if (!fdb)
739 return -ENOMEM;
740
741 modified = true;
742 } else {
743 if (flags & NLM_F_EXCL)
744 return -EEXIST;
745
746 if (fdb->dst != source) {
747 fdb->dst = source;
748 modified = true;
749 }
750 }
751
752 if (fdb_to_nud(fdb) != state) {
753 if (state & NUD_PERMANENT) {
754 fdb->is_local = 1;
755 if (!fdb->is_static) {
756 fdb->is_static = 1;
757 fdb_add_hw(br, addr);
758 }
759 } else if (state & NUD_NOARP) {
760 fdb->is_local = 0;
761 if (!fdb->is_static) {
762 fdb->is_static = 1;
763 fdb_add_hw(br, addr);
764 }
765 } else {
766 fdb->is_local = 0;
767 if (fdb->is_static) {
768 fdb->is_static = 0;
769 fdb_del_hw(br, addr);
770 }
771 }
772
773 modified = true;
774 }
775 fdb->added_by_user = 1;
776
777 fdb->used = jiffies;
778 if (modified) {
779 fdb->updated = jiffies;
780 fdb_notify(br, fdb, RTM_NEWNEIGH);
781 }
782
783 return 0;
784 }
785
__br_fdb_add(struct ndmsg * ndm,struct net_bridge_port * p,const unsigned char * addr,u16 nlh_flags,u16 vid)786 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p,
787 const unsigned char *addr, u16 nlh_flags, u16 vid)
788 {
789 int err = 0;
790
791 if (ndm->ndm_flags & NTF_USE) {
792 local_bh_disable();
793 rcu_read_lock();
794 br_fdb_update(p->br, p, addr, vid, true);
795 rcu_read_unlock();
796 local_bh_enable();
797 } else {
798 spin_lock_bh(&p->br->hash_lock);
799 err = fdb_add_entry(p, addr, ndm->ndm_state,
800 nlh_flags, vid);
801 spin_unlock_bh(&p->br->hash_lock);
802 }
803
804 return err;
805 }
806
807 /* Add new permanent fdb entry with RTM_NEWNEIGH */
br_fdb_add(struct ndmsg * ndm,struct nlattr * tb[],struct net_device * dev,const unsigned char * addr,u16 nlh_flags)808 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
809 struct net_device *dev,
810 const unsigned char *addr, u16 nlh_flags)
811 {
812 struct net_bridge_port *p;
813 int err = 0;
814 struct net_port_vlans *pv;
815 unsigned short vid = VLAN_N_VID;
816
817 if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
818 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
819 return -EINVAL;
820 }
821
822 if (tb[NDA_VLAN]) {
823 if (nla_len(tb[NDA_VLAN]) != sizeof(unsigned short)) {
824 pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
825 return -EINVAL;
826 }
827
828 vid = nla_get_u16(tb[NDA_VLAN]);
829
830 if (!vid || vid >= VLAN_VID_MASK) {
831 pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
832 vid);
833 return -EINVAL;
834 }
835 }
836
837 if (is_zero_ether_addr(addr)) {
838 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
839 return -EINVAL;
840 }
841
842 p = br_port_get_rtnl(dev);
843 if (p == NULL) {
844 pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
845 dev->name);
846 return -EINVAL;
847 }
848
849 pv = nbp_get_vlan_info(p);
850 if (vid != VLAN_N_VID) {
851 if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
852 pr_info("bridge: RTM_NEWNEIGH with unconfigured "
853 "vlan %d on port %s\n", vid, dev->name);
854 return -EINVAL;
855 }
856
857 /* VID was specified, so use it. */
858 err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
859 } else {
860 if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID)) {
861 err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
862 goto out;
863 }
864
865 /* We have vlans configured on this port and user didn't
866 * specify a VLAN. To be nice, add/update entry for every
867 * vlan on this port.
868 */
869 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
870 err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
871 if (err)
872 goto out;
873 }
874 }
875
876 out:
877 return err;
878 }
879
fdb_delete_by_addr(struct net_bridge * br,const u8 * addr,u16 vlan)880 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr, u16 vlan)
881 {
882 struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
883 struct net_bridge_fdb_entry *fdb;
884
885 fdb = fdb_find(head, addr, vlan);
886 if (!fdb)
887 return -ENOENT;
888
889 fdb_delete(br, fdb);
890 return 0;
891 }
892
__br_fdb_delete(struct net_bridge_port * p,const unsigned char * addr,u16 vid)893 static int __br_fdb_delete(struct net_bridge_port *p,
894 const unsigned char *addr, u16 vid)
895 {
896 int err;
897
898 spin_lock_bh(&p->br->hash_lock);
899 err = fdb_delete_by_addr(p->br, addr, vid);
900 spin_unlock_bh(&p->br->hash_lock);
901
902 return err;
903 }
904
905 /* Remove neighbor entry with RTM_DELNEIGH */
br_fdb_delete(struct ndmsg * ndm,struct nlattr * tb[],struct net_device * dev,const unsigned char * addr)906 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
907 struct net_device *dev,
908 const unsigned char *addr)
909 {
910 struct net_bridge_port *p;
911 int err;
912 struct net_port_vlans *pv;
913 unsigned short vid = VLAN_N_VID;
914
915 if (tb[NDA_VLAN]) {
916 if (nla_len(tb[NDA_VLAN]) != sizeof(unsigned short)) {
917 pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
918 return -EINVAL;
919 }
920
921 vid = nla_get_u16(tb[NDA_VLAN]);
922
923 if (!vid || vid >= VLAN_VID_MASK) {
924 pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
925 vid);
926 return -EINVAL;
927 }
928 }
929 p = br_port_get_rtnl(dev);
930 if (p == NULL) {
931 pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
932 dev->name);
933 return -EINVAL;
934 }
935
936 pv = nbp_get_vlan_info(p);
937 if (vid != VLAN_N_VID) {
938 if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
939 pr_info("bridge: RTM_DELNEIGH with unconfigured "
940 "vlan %d on port %s\n", vid, dev->name);
941 return -EINVAL;
942 }
943
944 err = __br_fdb_delete(p, addr, vid);
945 } else {
946 if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID)) {
947 err = __br_fdb_delete(p, addr, 0);
948 goto out;
949 }
950
951 /* We have vlans configured on this port and user didn't
952 * specify a VLAN. To be nice, add/update entry for every
953 * vlan on this port.
954 */
955 err = -ENOENT;
956 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
957 err &= __br_fdb_delete(p, addr, vid);
958 }
959 }
960 out:
961 return err;
962 }
963
br_fdb_sync_static(struct net_bridge * br,struct net_bridge_port * p)964 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
965 {
966 struct net_bridge_fdb_entry *fdb, *tmp;
967 int i;
968 int err;
969
970 ASSERT_RTNL();
971
972 for (i = 0; i < BR_HASH_SIZE; i++) {
973 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
974 /* We only care for static entries */
975 if (!fdb->is_static)
976 continue;
977
978 err = dev_uc_add(p->dev, fdb->addr.addr);
979 if (err)
980 goto rollback;
981 }
982 }
983 return 0;
984
985 rollback:
986 for (i = 0; i < BR_HASH_SIZE; i++) {
987 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
988 /* If we reached the fdb that failed, we can stop */
989 if (tmp == fdb)
990 break;
991
992 /* We only care for static entries */
993 if (!tmp->is_static)
994 continue;
995
996 dev_uc_del(p->dev, tmp->addr.addr);
997 }
998 }
999 return err;
1000 }
1001
br_fdb_unsync_static(struct net_bridge * br,struct net_bridge_port * p)1002 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1003 {
1004 struct net_bridge_fdb_entry *fdb;
1005 int i;
1006
1007 ASSERT_RTNL();
1008
1009 for (i = 0; i < BR_HASH_SIZE; i++) {
1010 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1011 /* We only care for static entries */
1012 if (!fdb->is_static)
1013 continue;
1014
1015 dev_uc_del(p->dev, fdb->addr.addr);
1016 }
1017 }
1018 }
1019