xref: /openbmc/linux/net/bridge/br_fdb.c (revision ae3473231e77a3f1909d48cd144cebe5e1d049b3)
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 <net/switchdev.h>
28 #include "br_private.h"
29 
30 static struct kmem_cache *br_fdb_cache __read_mostly;
31 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
32 					     const unsigned char *addr,
33 					     __u16 vid);
34 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
35 		      const unsigned char *addr, u16 vid);
36 static void fdb_notify(struct net_bridge *br,
37 		       const struct net_bridge_fdb_entry *, int);
38 
39 static u32 fdb_salt __read_mostly;
40 
41 int __init br_fdb_init(void)
42 {
43 	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
44 					 sizeof(struct net_bridge_fdb_entry),
45 					 0,
46 					 SLAB_HWCACHE_ALIGN, NULL);
47 	if (!br_fdb_cache)
48 		return -ENOMEM;
49 
50 	get_random_bytes(&fdb_salt, sizeof(fdb_salt));
51 	return 0;
52 }
53 
54 void br_fdb_fini(void)
55 {
56 	kmem_cache_destroy(br_fdb_cache);
57 }
58 
59 
60 /* if topology_changing then use forward_delay (default 15 sec)
61  * otherwise keep longer (default 5 minutes)
62  */
63 static inline unsigned long hold_time(const struct net_bridge *br)
64 {
65 	return br->topology_change ? br->forward_delay : br->ageing_time;
66 }
67 
68 static inline int has_expired(const struct net_bridge *br,
69 				  const struct net_bridge_fdb_entry *fdb)
70 {
71 	return !fdb->is_static &&
72 		time_before_eq(fdb->updated + hold_time(br), jiffies);
73 }
74 
75 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
76 {
77 	/* use 1 byte of OUI and 3 bytes of NIC */
78 	u32 key = get_unaligned((u32 *)(mac + 2));
79 	return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
80 }
81 
82 static void fdb_rcu_free(struct rcu_head *head)
83 {
84 	struct net_bridge_fdb_entry *ent
85 		= container_of(head, struct net_bridge_fdb_entry, rcu);
86 	kmem_cache_free(br_fdb_cache, ent);
87 }
88 
89 /* When a static FDB entry is added, the mac address from the entry is
90  * added to the bridge private HW address list and all required ports
91  * are then updated with the new information.
92  * Called under RTNL.
93  */
94 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
95 {
96 	int err;
97 	struct net_bridge_port *p;
98 
99 	ASSERT_RTNL();
100 
101 	list_for_each_entry(p, &br->port_list, list) {
102 		if (!br_promisc_port(p)) {
103 			err = dev_uc_add(p->dev, addr);
104 			if (err)
105 				goto undo;
106 		}
107 	}
108 
109 	return;
110 undo:
111 	list_for_each_entry_continue_reverse(p, &br->port_list, list) {
112 		if (!br_promisc_port(p))
113 			dev_uc_del(p->dev, addr);
114 	}
115 }
116 
117 /* When a static FDB entry is deleted, the HW address from that entry is
118  * also removed from the bridge private HW address list and updates all
119  * the ports with needed information.
120  * Called under RTNL.
121  */
122 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
123 {
124 	struct net_bridge_port *p;
125 
126 	ASSERT_RTNL();
127 
128 	list_for_each_entry(p, &br->port_list, list) {
129 		if (!br_promisc_port(p))
130 			dev_uc_del(p->dev, addr);
131 	}
132 }
133 
134 static void fdb_del_external_learn(struct net_bridge_fdb_entry *f)
135 {
136 	struct switchdev_obj_port_fdb fdb = {
137 		.obj = {
138 			.orig_dev = f->dst->dev,
139 			.id = SWITCHDEV_OBJ_ID_PORT_FDB,
140 			.flags = SWITCHDEV_F_DEFER,
141 		},
142 		.vid = f->vlan_id,
143 	};
144 
145 	ether_addr_copy(fdb.addr, f->addr.addr);
146 	switchdev_port_obj_del(f->dst->dev, &fdb.obj);
147 }
148 
149 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
150 {
151 	if (f->is_static)
152 		fdb_del_hw_addr(br, f->addr.addr);
153 
154 	if (f->added_by_external_learn)
155 		fdb_del_external_learn(f);
156 
157 	hlist_del_rcu(&f->hlist);
158 	fdb_notify(br, f, RTM_DELNEIGH);
159 	call_rcu(&f->rcu, fdb_rcu_free);
160 }
161 
162 /* Delete a local entry if no other port had the same address. */
163 static void fdb_delete_local(struct net_bridge *br,
164 			     const struct net_bridge_port *p,
165 			     struct net_bridge_fdb_entry *f)
166 {
167 	const unsigned char *addr = f->addr.addr;
168 	struct net_bridge_vlan_group *vg;
169 	const struct net_bridge_vlan *v;
170 	struct net_bridge_port *op;
171 	u16 vid = f->vlan_id;
172 
173 	/* Maybe another port has same hw addr? */
174 	list_for_each_entry(op, &br->port_list, list) {
175 		vg = nbp_vlan_group(op);
176 		if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
177 		    (!vid || br_vlan_find(vg, vid))) {
178 			f->dst = op;
179 			f->added_by_user = 0;
180 			return;
181 		}
182 	}
183 
184 	vg = br_vlan_group(br);
185 	v = br_vlan_find(vg, vid);
186 	/* Maybe bridge device has same hw addr? */
187 	if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
188 	    (!vid || (v && br_vlan_should_use(v)))) {
189 		f->dst = NULL;
190 		f->added_by_user = 0;
191 		return;
192 	}
193 
194 	fdb_delete(br, f);
195 }
196 
197 void br_fdb_find_delete_local(struct net_bridge *br,
198 			      const struct net_bridge_port *p,
199 			      const unsigned char *addr, u16 vid)
200 {
201 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
202 	struct net_bridge_fdb_entry *f;
203 
204 	spin_lock_bh(&br->hash_lock);
205 	f = fdb_find(head, addr, vid);
206 	if (f && f->is_local && !f->added_by_user && f->dst == p)
207 		fdb_delete_local(br, p, f);
208 	spin_unlock_bh(&br->hash_lock);
209 }
210 
211 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
212 {
213 	struct net_bridge_vlan_group *vg;
214 	struct net_bridge *br = p->br;
215 	struct net_bridge_vlan *v;
216 	int i;
217 
218 	spin_lock_bh(&br->hash_lock);
219 
220 	vg = nbp_vlan_group(p);
221 	/* Search all chains since old address/hash is unknown */
222 	for (i = 0; i < BR_HASH_SIZE; i++) {
223 		struct hlist_node *h;
224 		hlist_for_each(h, &br->hash[i]) {
225 			struct net_bridge_fdb_entry *f;
226 
227 			f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
228 			if (f->dst == p && f->is_local && !f->added_by_user) {
229 				/* delete old one */
230 				fdb_delete_local(br, p, f);
231 
232 				/* if this port has no vlan information
233 				 * configured, we can safely be done at
234 				 * this point.
235 				 */
236 				if (!vg || !vg->num_vlans)
237 					goto insert;
238 			}
239 		}
240 	}
241 
242 insert:
243 	/* insert new address,  may fail if invalid address or dup. */
244 	fdb_insert(br, p, newaddr, 0);
245 
246 	if (!vg || !vg->num_vlans)
247 		goto done;
248 
249 	/* Now add entries for every VLAN configured on the port.
250 	 * This function runs under RTNL so the bitmap will not change
251 	 * from under us.
252 	 */
253 	list_for_each_entry(v, &vg->vlan_list, vlist)
254 		fdb_insert(br, p, newaddr, v->vid);
255 
256 done:
257 	spin_unlock_bh(&br->hash_lock);
258 }
259 
260 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
261 {
262 	struct net_bridge_vlan_group *vg;
263 	struct net_bridge_fdb_entry *f;
264 	struct net_bridge_vlan *v;
265 
266 	spin_lock_bh(&br->hash_lock);
267 
268 	/* If old entry was unassociated with any port, then delete it. */
269 	f = __br_fdb_get(br, br->dev->dev_addr, 0);
270 	if (f && f->is_local && !f->dst && !f->added_by_user)
271 		fdb_delete_local(br, NULL, f);
272 
273 	fdb_insert(br, NULL, newaddr, 0);
274 	vg = br_vlan_group(br);
275 	if (!vg || !vg->num_vlans)
276 		goto out;
277 	/* Now remove and add entries for every VLAN configured on the
278 	 * bridge.  This function runs under RTNL so the bitmap will not
279 	 * change from under us.
280 	 */
281 	list_for_each_entry(v, &vg->vlan_list, vlist) {
282 		if (!br_vlan_should_use(v))
283 			continue;
284 		f = __br_fdb_get(br, br->dev->dev_addr, v->vid);
285 		if (f && f->is_local && !f->dst && !f->added_by_user)
286 			fdb_delete_local(br, NULL, f);
287 		fdb_insert(br, NULL, newaddr, v->vid);
288 	}
289 out:
290 	spin_unlock_bh(&br->hash_lock);
291 }
292 
293 void br_fdb_cleanup(unsigned long _data)
294 {
295 	struct net_bridge *br = (struct net_bridge *)_data;
296 	unsigned long delay = hold_time(br);
297 	unsigned long next_timer = jiffies + br->ageing_time;
298 	int i;
299 
300 	spin_lock(&br->hash_lock);
301 	for (i = 0; i < BR_HASH_SIZE; i++) {
302 		struct net_bridge_fdb_entry *f;
303 		struct hlist_node *n;
304 
305 		hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
306 			unsigned long this_timer;
307 			if (f->is_static)
308 				continue;
309 			if (f->added_by_external_learn)
310 				continue;
311 			this_timer = f->updated + delay;
312 			if (time_before_eq(this_timer, jiffies))
313 				fdb_delete(br, f);
314 			else if (time_before(this_timer, next_timer))
315 				next_timer = this_timer;
316 		}
317 	}
318 	spin_unlock(&br->hash_lock);
319 
320 	mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
321 }
322 
323 /* Completely flush all dynamic entries in forwarding database.*/
324 void br_fdb_flush(struct net_bridge *br)
325 {
326 	int i;
327 
328 	spin_lock_bh(&br->hash_lock);
329 	for (i = 0; i < BR_HASH_SIZE; i++) {
330 		struct net_bridge_fdb_entry *f;
331 		struct hlist_node *n;
332 		hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
333 			if (!f->is_static)
334 				fdb_delete(br, f);
335 		}
336 	}
337 	spin_unlock_bh(&br->hash_lock);
338 }
339 
340 /* Flush all entries referring to a specific port.
341  * if do_all is set also flush static entries
342  * if vid is set delete all entries that match the vlan_id
343  */
344 void br_fdb_delete_by_port(struct net_bridge *br,
345 			   const struct net_bridge_port *p,
346 			   u16 vid,
347 			   int do_all)
348 {
349 	int i;
350 
351 	spin_lock_bh(&br->hash_lock);
352 	for (i = 0; i < BR_HASH_SIZE; i++) {
353 		struct hlist_node *h, *g;
354 
355 		hlist_for_each_safe(h, g, &br->hash[i]) {
356 			struct net_bridge_fdb_entry *f
357 				= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
358 			if (f->dst != p)
359 				continue;
360 
361 			if (!do_all)
362 				if (f->is_static || (vid && f->vlan_id != vid))
363 					continue;
364 
365 			if (f->is_local)
366 				fdb_delete_local(br, p, f);
367 			else
368 				fdb_delete(br, f);
369 		}
370 	}
371 	spin_unlock_bh(&br->hash_lock);
372 }
373 
374 /* No locking or refcounting, assumes caller has rcu_read_lock */
375 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
376 					  const unsigned char *addr,
377 					  __u16 vid)
378 {
379 	struct net_bridge_fdb_entry *fdb;
380 
381 	hlist_for_each_entry_rcu(fdb,
382 				&br->hash[br_mac_hash(addr, vid)], hlist) {
383 		if (ether_addr_equal(fdb->addr.addr, addr) &&
384 		    fdb->vlan_id == vid) {
385 			if (unlikely(has_expired(br, fdb)))
386 				break;
387 			return fdb;
388 		}
389 	}
390 
391 	return NULL;
392 }
393 
394 #if IS_ENABLED(CONFIG_ATM_LANE)
395 /* Interface used by ATM LANE hook to test
396  * if an addr is on some other bridge port */
397 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
398 {
399 	struct net_bridge_fdb_entry *fdb;
400 	struct net_bridge_port *port;
401 	int ret;
402 
403 	rcu_read_lock();
404 	port = br_port_get_rcu(dev);
405 	if (!port)
406 		ret = 0;
407 	else {
408 		fdb = __br_fdb_get(port->br, addr, 0);
409 		ret = fdb && fdb->dst && fdb->dst->dev != dev &&
410 			fdb->dst->state == BR_STATE_FORWARDING;
411 	}
412 	rcu_read_unlock();
413 
414 	return ret;
415 }
416 #endif /* CONFIG_ATM_LANE */
417 
418 /*
419  * Fill buffer with forwarding table records in
420  * the API format.
421  */
422 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
423 		   unsigned long maxnum, unsigned long skip)
424 {
425 	struct __fdb_entry *fe = buf;
426 	int i, num = 0;
427 	struct net_bridge_fdb_entry *f;
428 
429 	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
430 
431 	rcu_read_lock();
432 	for (i = 0; i < BR_HASH_SIZE; i++) {
433 		hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
434 			if (num >= maxnum)
435 				goto out;
436 
437 			if (has_expired(br, f))
438 				continue;
439 
440 			/* ignore pseudo entry for local MAC address */
441 			if (!f->dst)
442 				continue;
443 
444 			if (skip) {
445 				--skip;
446 				continue;
447 			}
448 
449 			/* convert from internal format to API */
450 			memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
451 
452 			/* due to ABI compat need to split into hi/lo */
453 			fe->port_no = f->dst->port_no;
454 			fe->port_hi = f->dst->port_no >> 8;
455 
456 			fe->is_local = f->is_local;
457 			if (!f->is_static)
458 				fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
459 			++fe;
460 			++num;
461 		}
462 	}
463 
464  out:
465 	rcu_read_unlock();
466 
467 	return num;
468 }
469 
470 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
471 					     const unsigned char *addr,
472 					     __u16 vid)
473 {
474 	struct net_bridge_fdb_entry *fdb;
475 
476 	hlist_for_each_entry(fdb, head, hlist) {
477 		if (ether_addr_equal(fdb->addr.addr, addr) &&
478 		    fdb->vlan_id == vid)
479 			return fdb;
480 	}
481 	return NULL;
482 }
483 
484 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
485 						 const unsigned char *addr,
486 						 __u16 vid)
487 {
488 	struct net_bridge_fdb_entry *fdb;
489 
490 	hlist_for_each_entry_rcu(fdb, head, hlist) {
491 		if (ether_addr_equal(fdb->addr.addr, addr) &&
492 		    fdb->vlan_id == vid)
493 			return fdb;
494 	}
495 	return NULL;
496 }
497 
498 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
499 					       struct net_bridge_port *source,
500 					       const unsigned char *addr,
501 					       __u16 vid,
502 					       unsigned char is_local,
503 					       unsigned char is_static)
504 {
505 	struct net_bridge_fdb_entry *fdb;
506 
507 	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
508 	if (fdb) {
509 		memcpy(fdb->addr.addr, addr, ETH_ALEN);
510 		fdb->dst = source;
511 		fdb->vlan_id = vid;
512 		fdb->is_local = is_local;
513 		fdb->is_static = is_static;
514 		fdb->added_by_user = 0;
515 		fdb->added_by_external_learn = 0;
516 		fdb->updated = fdb->used = jiffies;
517 		hlist_add_head_rcu(&fdb->hlist, head);
518 	}
519 	return fdb;
520 }
521 
522 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
523 		  const unsigned char *addr, u16 vid)
524 {
525 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
526 	struct net_bridge_fdb_entry *fdb;
527 
528 	if (!is_valid_ether_addr(addr))
529 		return -EINVAL;
530 
531 	fdb = fdb_find(head, addr, vid);
532 	if (fdb) {
533 		/* it is okay to have multiple ports with same
534 		 * address, just use the first one.
535 		 */
536 		if (fdb->is_local)
537 			return 0;
538 		br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
539 		       source ? source->dev->name : br->dev->name, addr, vid);
540 		fdb_delete(br, fdb);
541 	}
542 
543 	fdb = fdb_create(head, source, addr, vid, 1, 1);
544 	if (!fdb)
545 		return -ENOMEM;
546 
547 	fdb_add_hw_addr(br, addr);
548 	fdb_notify(br, fdb, RTM_NEWNEIGH);
549 	return 0;
550 }
551 
552 /* Add entry for local address of interface */
553 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
554 		  const unsigned char *addr, u16 vid)
555 {
556 	int ret;
557 
558 	spin_lock_bh(&br->hash_lock);
559 	ret = fdb_insert(br, source, addr, vid);
560 	spin_unlock_bh(&br->hash_lock);
561 	return ret;
562 }
563 
564 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
565 		   const unsigned char *addr, u16 vid, bool added_by_user)
566 {
567 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
568 	struct net_bridge_fdb_entry *fdb;
569 	bool fdb_modified = false;
570 
571 	/* some users want to always flood. */
572 	if (hold_time(br) == 0)
573 		return;
574 
575 	/* ignore packets unless we are using this port */
576 	if (!(source->state == BR_STATE_LEARNING ||
577 	      source->state == BR_STATE_FORWARDING))
578 		return;
579 
580 	fdb = fdb_find_rcu(head, addr, vid);
581 	if (likely(fdb)) {
582 		/* attempt to update an entry for a local interface */
583 		if (unlikely(fdb->is_local)) {
584 			if (net_ratelimit())
585 				br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
586 					source->dev->name, addr, vid);
587 		} else {
588 			/* fastpath: update of existing entry */
589 			if (unlikely(source != fdb->dst)) {
590 				fdb->dst = source;
591 				fdb_modified = true;
592 			}
593 			fdb->updated = jiffies;
594 			if (unlikely(added_by_user))
595 				fdb->added_by_user = 1;
596 			if (unlikely(fdb_modified))
597 				fdb_notify(br, fdb, RTM_NEWNEIGH);
598 		}
599 	} else {
600 		spin_lock(&br->hash_lock);
601 		if (likely(!fdb_find(head, addr, vid))) {
602 			fdb = fdb_create(head, source, addr, vid, 0, 0);
603 			if (fdb) {
604 				if (unlikely(added_by_user))
605 					fdb->added_by_user = 1;
606 				fdb_notify(br, fdb, RTM_NEWNEIGH);
607 			}
608 		}
609 		/* else  we lose race and someone else inserts
610 		 * it first, don't bother updating
611 		 */
612 		spin_unlock(&br->hash_lock);
613 	}
614 }
615 
616 static int fdb_to_nud(const struct net_bridge *br,
617 		      const struct net_bridge_fdb_entry *fdb)
618 {
619 	if (fdb->is_local)
620 		return NUD_PERMANENT;
621 	else if (fdb->is_static)
622 		return NUD_NOARP;
623 	else if (has_expired(br, fdb))
624 		return NUD_STALE;
625 	else
626 		return NUD_REACHABLE;
627 }
628 
629 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
630 			 const struct net_bridge_fdb_entry *fdb,
631 			 u32 portid, u32 seq, int type, unsigned int flags)
632 {
633 	unsigned long now = jiffies;
634 	struct nda_cacheinfo ci;
635 	struct nlmsghdr *nlh;
636 	struct ndmsg *ndm;
637 
638 	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
639 	if (nlh == NULL)
640 		return -EMSGSIZE;
641 
642 	ndm = nlmsg_data(nlh);
643 	ndm->ndm_family	 = AF_BRIDGE;
644 	ndm->ndm_pad1    = 0;
645 	ndm->ndm_pad2    = 0;
646 	ndm->ndm_flags	 = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0;
647 	ndm->ndm_type	 = 0;
648 	ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
649 	ndm->ndm_state   = fdb_to_nud(br, fdb);
650 
651 	if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
652 		goto nla_put_failure;
653 	if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
654 		goto nla_put_failure;
655 	ci.ndm_used	 = jiffies_to_clock_t(now - fdb->used);
656 	ci.ndm_confirmed = 0;
657 	ci.ndm_updated	 = jiffies_to_clock_t(now - fdb->updated);
658 	ci.ndm_refcnt	 = 0;
659 	if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
660 		goto nla_put_failure;
661 
662 	if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
663 		goto nla_put_failure;
664 
665 	nlmsg_end(skb, nlh);
666 	return 0;
667 
668 nla_put_failure:
669 	nlmsg_cancel(skb, nlh);
670 	return -EMSGSIZE;
671 }
672 
673 static inline size_t fdb_nlmsg_size(void)
674 {
675 	return NLMSG_ALIGN(sizeof(struct ndmsg))
676 		+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
677 		+ nla_total_size(sizeof(u32)) /* NDA_MASTER */
678 		+ nla_total_size(sizeof(u16)) /* NDA_VLAN */
679 		+ nla_total_size(sizeof(struct nda_cacheinfo));
680 }
681 
682 static void fdb_notify(struct net_bridge *br,
683 		       const struct net_bridge_fdb_entry *fdb, int type)
684 {
685 	struct net *net = dev_net(br->dev);
686 	struct sk_buff *skb;
687 	int err = -ENOBUFS;
688 
689 	skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
690 	if (skb == NULL)
691 		goto errout;
692 
693 	err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
694 	if (err < 0) {
695 		/* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
696 		WARN_ON(err == -EMSGSIZE);
697 		kfree_skb(skb);
698 		goto errout;
699 	}
700 	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
701 	return;
702 errout:
703 	rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
704 }
705 
706 /* Dump information about entries, in response to GETNEIGH */
707 int br_fdb_dump(struct sk_buff *skb,
708 		struct netlink_callback *cb,
709 		struct net_device *dev,
710 		struct net_device *filter_dev,
711 		int *idx)
712 {
713 	struct net_bridge *br = netdev_priv(dev);
714 	int err = 0;
715 	int i;
716 
717 	if (!(dev->priv_flags & IFF_EBRIDGE))
718 		goto out;
719 
720 	if (!filter_dev) {
721 		err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
722 		if (err < 0)
723 			goto out;
724 	}
725 
726 	for (i = 0; i < BR_HASH_SIZE; i++) {
727 		struct net_bridge_fdb_entry *f;
728 
729 		hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
730 
731 			if (*idx < cb->args[2])
732 				goto skip;
733 
734 			if (filter_dev &&
735 			    (!f->dst || f->dst->dev != filter_dev)) {
736 				if (filter_dev != dev)
737 					goto skip;
738 				/* !f->dst is a special case for bridge
739 				 * It means the MAC belongs to the bridge
740 				 * Therefore need a little more filtering
741 				 * we only want to dump the !f->dst case
742 				 */
743 				if (f->dst)
744 					goto skip;
745 			}
746 			if (!filter_dev && f->dst)
747 				goto skip;
748 
749 			err = fdb_fill_info(skb, br, f,
750 					    NETLINK_CB(cb->skb).portid,
751 					    cb->nlh->nlmsg_seq,
752 					    RTM_NEWNEIGH,
753 					    NLM_F_MULTI);
754 			if (err < 0)
755 				goto out;
756 skip:
757 			*idx += 1;
758 		}
759 	}
760 
761 out:
762 	return err;
763 }
764 
765 /* Update (create or replace) forwarding database entry */
766 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
767 			 const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
768 {
769 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
770 	struct net_bridge_fdb_entry *fdb;
771 	bool modified = false;
772 
773 	/* If the port cannot learn allow only local and static entries */
774 	if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
775 	    !(source->state == BR_STATE_LEARNING ||
776 	      source->state == BR_STATE_FORWARDING))
777 		return -EPERM;
778 
779 	if (!source && !(state & NUD_PERMANENT)) {
780 		pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
781 			br->dev->name);
782 		return -EINVAL;
783 	}
784 
785 	fdb = fdb_find(head, addr, vid);
786 	if (fdb == NULL) {
787 		if (!(flags & NLM_F_CREATE))
788 			return -ENOENT;
789 
790 		fdb = fdb_create(head, source, addr, vid, 0, 0);
791 		if (!fdb)
792 			return -ENOMEM;
793 
794 		modified = true;
795 	} else {
796 		if (flags & NLM_F_EXCL)
797 			return -EEXIST;
798 
799 		if (fdb->dst != source) {
800 			fdb->dst = source;
801 			modified = true;
802 		}
803 	}
804 
805 	if (fdb_to_nud(br, fdb) != state) {
806 		if (state & NUD_PERMANENT) {
807 			fdb->is_local = 1;
808 			if (!fdb->is_static) {
809 				fdb->is_static = 1;
810 				fdb_add_hw_addr(br, addr);
811 			}
812 		} else if (state & NUD_NOARP) {
813 			fdb->is_local = 0;
814 			if (!fdb->is_static) {
815 				fdb->is_static = 1;
816 				fdb_add_hw_addr(br, addr);
817 			}
818 		} else {
819 			fdb->is_local = 0;
820 			if (fdb->is_static) {
821 				fdb->is_static = 0;
822 				fdb_del_hw_addr(br, addr);
823 			}
824 		}
825 
826 		modified = true;
827 	}
828 	fdb->added_by_user = 1;
829 
830 	fdb->used = jiffies;
831 	if (modified) {
832 		fdb->updated = jiffies;
833 		fdb_notify(br, fdb, RTM_NEWNEIGH);
834 	}
835 
836 	return 0;
837 }
838 
839 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
840 			struct net_bridge_port *p, const unsigned char *addr,
841 			u16 nlh_flags, u16 vid)
842 {
843 	int err = 0;
844 
845 	if (ndm->ndm_flags & NTF_USE) {
846 		if (!p) {
847 			pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
848 				br->dev->name);
849 			return -EINVAL;
850 		}
851 		local_bh_disable();
852 		rcu_read_lock();
853 		br_fdb_update(br, p, addr, vid, true);
854 		rcu_read_unlock();
855 		local_bh_enable();
856 	} else {
857 		spin_lock_bh(&br->hash_lock);
858 		err = fdb_add_entry(br, p, addr, ndm->ndm_state,
859 				    nlh_flags, vid);
860 		spin_unlock_bh(&br->hash_lock);
861 	}
862 
863 	return err;
864 }
865 
866 /* Add new permanent fdb entry with RTM_NEWNEIGH */
867 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
868 	       struct net_device *dev,
869 	       const unsigned char *addr, u16 vid, u16 nlh_flags)
870 {
871 	struct net_bridge_vlan_group *vg;
872 	struct net_bridge_port *p = NULL;
873 	struct net_bridge_vlan *v;
874 	struct net_bridge *br = NULL;
875 	int err = 0;
876 
877 	if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
878 		pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
879 		return -EINVAL;
880 	}
881 
882 	if (is_zero_ether_addr(addr)) {
883 		pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
884 		return -EINVAL;
885 	}
886 
887 	if (dev->priv_flags & IFF_EBRIDGE) {
888 		br = netdev_priv(dev);
889 		vg = br_vlan_group(br);
890 	} else {
891 		p = br_port_get_rtnl(dev);
892 		if (!p) {
893 			pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
894 				dev->name);
895 			return -EINVAL;
896 		}
897 		br = p->br;
898 		vg = nbp_vlan_group(p);
899 	}
900 
901 	if (vid) {
902 		v = br_vlan_find(vg, vid);
903 		if (!v || !br_vlan_should_use(v)) {
904 			pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
905 			return -EINVAL;
906 		}
907 
908 		/* VID was specified, so use it. */
909 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
910 	} else {
911 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
912 		if (err || !vg || !vg->num_vlans)
913 			goto out;
914 
915 		/* We have vlans configured on this port and user didn't
916 		 * specify a VLAN.  To be nice, add/update entry for every
917 		 * vlan on this port.
918 		 */
919 		list_for_each_entry(v, &vg->vlan_list, vlist) {
920 			if (!br_vlan_should_use(v))
921 				continue;
922 			err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
923 			if (err)
924 				goto out;
925 		}
926 	}
927 
928 out:
929 	return err;
930 }
931 
932 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr,
933 			      u16 vid)
934 {
935 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
936 	struct net_bridge_fdb_entry *fdb;
937 
938 	fdb = fdb_find(head, addr, vid);
939 	if (!fdb)
940 		return -ENOENT;
941 
942 	fdb_delete(br, fdb);
943 	return 0;
944 }
945 
946 static int __br_fdb_delete_by_addr(struct net_bridge *br,
947 				   const unsigned char *addr, u16 vid)
948 {
949 	int err;
950 
951 	spin_lock_bh(&br->hash_lock);
952 	err = fdb_delete_by_addr(br, addr, vid);
953 	spin_unlock_bh(&br->hash_lock);
954 
955 	return err;
956 }
957 
958 static int fdb_delete_by_addr_and_port(struct net_bridge_port *p,
959 				       const u8 *addr, u16 vlan)
960 {
961 	struct net_bridge *br = p->br;
962 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
963 	struct net_bridge_fdb_entry *fdb;
964 
965 	fdb = fdb_find(head, addr, vlan);
966 	if (!fdb || fdb->dst != p)
967 		return -ENOENT;
968 
969 	fdb_delete(br, fdb);
970 	return 0;
971 }
972 
973 static int __br_fdb_delete(struct net_bridge_port *p,
974 			   const unsigned char *addr, u16 vid)
975 {
976 	int err;
977 
978 	spin_lock_bh(&p->br->hash_lock);
979 	err = fdb_delete_by_addr_and_port(p, addr, vid);
980 	spin_unlock_bh(&p->br->hash_lock);
981 
982 	return err;
983 }
984 
985 /* Remove neighbor entry with RTM_DELNEIGH */
986 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
987 		  struct net_device *dev,
988 		  const unsigned char *addr, u16 vid)
989 {
990 	struct net_bridge_vlan_group *vg;
991 	struct net_bridge_port *p = NULL;
992 	struct net_bridge_vlan *v;
993 	struct net_bridge *br = NULL;
994 	int err;
995 
996 	if (dev->priv_flags & IFF_EBRIDGE) {
997 		br = netdev_priv(dev);
998 		vg = br_vlan_group(br);
999 	} else {
1000 		p = br_port_get_rtnl(dev);
1001 		if (!p) {
1002 			pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1003 				dev->name);
1004 			return -EINVAL;
1005 		}
1006 		vg = nbp_vlan_group(p);
1007 	}
1008 
1009 	if (vid) {
1010 		v = br_vlan_find(vg, vid);
1011 		if (!v) {
1012 			pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1013 			return -EINVAL;
1014 		}
1015 
1016 		if (dev->priv_flags & IFF_EBRIDGE)
1017 			err = __br_fdb_delete_by_addr(br, addr, vid);
1018 		else
1019 			err = __br_fdb_delete(p, addr, vid);
1020 	} else {
1021 		err = -ENOENT;
1022 		if (dev->priv_flags & IFF_EBRIDGE)
1023 			err = __br_fdb_delete_by_addr(br, addr, 0);
1024 		else
1025 			err &= __br_fdb_delete(p, addr, 0);
1026 
1027 		if (!vg || !vg->num_vlans)
1028 			goto out;
1029 
1030 		list_for_each_entry(v, &vg->vlan_list, vlist) {
1031 			if (!br_vlan_should_use(v))
1032 				continue;
1033 			if (dev->priv_flags & IFF_EBRIDGE)
1034 				err = __br_fdb_delete_by_addr(br, addr, v->vid);
1035 			else
1036 				err &= __br_fdb_delete(p, addr, v->vid);
1037 		}
1038 	}
1039 out:
1040 	return err;
1041 }
1042 
1043 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1044 {
1045 	struct net_bridge_fdb_entry *fdb, *tmp;
1046 	int i;
1047 	int err;
1048 
1049 	ASSERT_RTNL();
1050 
1051 	for (i = 0; i < BR_HASH_SIZE; i++) {
1052 		hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1053 			/* We only care for static entries */
1054 			if (!fdb->is_static)
1055 				continue;
1056 
1057 			err = dev_uc_add(p->dev, fdb->addr.addr);
1058 			if (err)
1059 				goto rollback;
1060 		}
1061 	}
1062 	return 0;
1063 
1064 rollback:
1065 	for (i = 0; i < BR_HASH_SIZE; i++) {
1066 		hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1067 			/* If we reached the fdb that failed, we can stop */
1068 			if (tmp == fdb)
1069 				break;
1070 
1071 			/* We only care for static entries */
1072 			if (!tmp->is_static)
1073 				continue;
1074 
1075 			dev_uc_del(p->dev, tmp->addr.addr);
1076 		}
1077 	}
1078 	return err;
1079 }
1080 
1081 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1082 {
1083 	struct net_bridge_fdb_entry *fdb;
1084 	int i;
1085 
1086 	ASSERT_RTNL();
1087 
1088 	for (i = 0; i < BR_HASH_SIZE; i++) {
1089 		hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1090 			/* We only care for static entries */
1091 			if (!fdb->is_static)
1092 				continue;
1093 
1094 			dev_uc_del(p->dev, fdb->addr.addr);
1095 		}
1096 	}
1097 }
1098 
1099 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1100 			      const unsigned char *addr, u16 vid)
1101 {
1102 	struct hlist_head *head;
1103 	struct net_bridge_fdb_entry *fdb;
1104 	int err = 0;
1105 
1106 	ASSERT_RTNL();
1107 	spin_lock_bh(&br->hash_lock);
1108 
1109 	head = &br->hash[br_mac_hash(addr, vid)];
1110 	fdb = fdb_find(head, addr, vid);
1111 	if (!fdb) {
1112 		fdb = fdb_create(head, p, addr, vid, 0, 0);
1113 		if (!fdb) {
1114 			err = -ENOMEM;
1115 			goto err_unlock;
1116 		}
1117 		fdb->added_by_external_learn = 1;
1118 		fdb_notify(br, fdb, RTM_NEWNEIGH);
1119 	} else if (fdb->added_by_external_learn) {
1120 		/* Refresh entry */
1121 		fdb->updated = fdb->used = jiffies;
1122 	} else if (!fdb->added_by_user) {
1123 		/* Take over SW learned entry */
1124 		fdb->added_by_external_learn = 1;
1125 		fdb->updated = jiffies;
1126 		fdb_notify(br, fdb, RTM_NEWNEIGH);
1127 	}
1128 
1129 err_unlock:
1130 	spin_unlock_bh(&br->hash_lock);
1131 
1132 	return err;
1133 }
1134 
1135 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1136 			      const unsigned char *addr, u16 vid)
1137 {
1138 	struct hlist_head *head;
1139 	struct net_bridge_fdb_entry *fdb;
1140 	int err = 0;
1141 
1142 	ASSERT_RTNL();
1143 	spin_lock_bh(&br->hash_lock);
1144 
1145 	head = &br->hash[br_mac_hash(addr, vid)];
1146 	fdb = fdb_find(head, addr, vid);
1147 	if (fdb && fdb->added_by_external_learn)
1148 		fdb_delete(br, fdb);
1149 	else
1150 		err = -ENOENT;
1151 
1152 	spin_unlock_bh(&br->hash_lock);
1153 
1154 	return err;
1155 }
1156