xref: /linux/net/bridge/br_fdb.c (revision d003d772e64df08af04ee63609d47169ee82ae0e)
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 <trace/events/bridge.h>
29 #include "br_private.h"
30 
31 static const struct rhashtable_params br_fdb_rht_params = {
32 	.head_offset = offsetof(struct net_bridge_fdb_entry, rhnode),
33 	.key_offset = offsetof(struct net_bridge_fdb_entry, key),
34 	.key_len = sizeof(struct net_bridge_fdb_key),
35 	.automatic_shrinking = true,
36 	.locks_mul = 1,
37 };
38 
39 static struct kmem_cache *br_fdb_cache __read_mostly;
40 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
41 		      const unsigned char *addr, u16 vid);
42 static void fdb_notify(struct net_bridge *br,
43 		       const struct net_bridge_fdb_entry *, int, bool);
44 
45 int __init br_fdb_init(void)
46 {
47 	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
48 					 sizeof(struct net_bridge_fdb_entry),
49 					 0,
50 					 SLAB_HWCACHE_ALIGN, NULL);
51 	if (!br_fdb_cache)
52 		return -ENOMEM;
53 
54 	return 0;
55 }
56 
57 void br_fdb_fini(void)
58 {
59 	kmem_cache_destroy(br_fdb_cache);
60 }
61 
62 int br_fdb_hash_init(struct net_bridge *br)
63 {
64 	return rhashtable_init(&br->fdb_hash_tbl, &br_fdb_rht_params);
65 }
66 
67 void br_fdb_hash_fini(struct net_bridge *br)
68 {
69 	rhashtable_destroy(&br->fdb_hash_tbl);
70 }
71 
72 /* if topology_changing then use forward_delay (default 15 sec)
73  * otherwise keep longer (default 5 minutes)
74  */
75 static inline unsigned long hold_time(const struct net_bridge *br)
76 {
77 	return br->topology_change ? br->forward_delay : br->ageing_time;
78 }
79 
80 static inline int has_expired(const struct net_bridge *br,
81 				  const struct net_bridge_fdb_entry *fdb)
82 {
83 	return !fdb->is_static && !fdb->added_by_external_learn &&
84 		time_before_eq(fdb->updated + hold_time(br), jiffies);
85 }
86 
87 static void fdb_rcu_free(struct rcu_head *head)
88 {
89 	struct net_bridge_fdb_entry *ent
90 		= container_of(head, struct net_bridge_fdb_entry, rcu);
91 	kmem_cache_free(br_fdb_cache, ent);
92 }
93 
94 static struct net_bridge_fdb_entry *fdb_find_rcu(struct rhashtable *tbl,
95 						 const unsigned char *addr,
96 						 __u16 vid)
97 {
98 	struct net_bridge_fdb_key key;
99 
100 	WARN_ON_ONCE(!rcu_read_lock_held());
101 
102 	key.vlan_id = vid;
103 	memcpy(key.addr.addr, addr, sizeof(key.addr.addr));
104 
105 	return rhashtable_lookup(tbl, &key, br_fdb_rht_params);
106 }
107 
108 /* requires bridge hash_lock */
109 static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
110 						const unsigned char *addr,
111 						__u16 vid)
112 {
113 	struct net_bridge_fdb_entry *fdb;
114 
115 	lockdep_assert_held_once(&br->hash_lock);
116 
117 	rcu_read_lock();
118 	fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
119 	rcu_read_unlock();
120 
121 	return fdb;
122 }
123 
124 struct net_device *br_fdb_find_port(const struct net_device *br_dev,
125 				    const unsigned char *addr,
126 				    __u16 vid)
127 {
128 	struct net_bridge_fdb_entry *f;
129 	struct net_device *dev = NULL;
130 	struct net_bridge *br;
131 
132 	ASSERT_RTNL();
133 
134 	if (!netif_is_bridge_master(br_dev))
135 		return NULL;
136 
137 	br = netdev_priv(br_dev);
138 	rcu_read_lock();
139 	f = br_fdb_find_rcu(br, addr, vid);
140 	if (f && f->dst)
141 		dev = f->dst->dev;
142 	rcu_read_unlock();
143 
144 	return dev;
145 }
146 EXPORT_SYMBOL_GPL(br_fdb_find_port);
147 
148 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
149 					     const unsigned char *addr,
150 					     __u16 vid)
151 {
152 	return fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
153 }
154 
155 /* When a static FDB entry is added, the mac address from the entry is
156  * added to the bridge private HW address list and all required ports
157  * are then updated with the new information.
158  * Called under RTNL.
159  */
160 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
161 {
162 	int err;
163 	struct net_bridge_port *p;
164 
165 	ASSERT_RTNL();
166 
167 	list_for_each_entry(p, &br->port_list, list) {
168 		if (!br_promisc_port(p)) {
169 			err = dev_uc_add(p->dev, addr);
170 			if (err)
171 				goto undo;
172 		}
173 	}
174 
175 	return;
176 undo:
177 	list_for_each_entry_continue_reverse(p, &br->port_list, list) {
178 		if (!br_promisc_port(p))
179 			dev_uc_del(p->dev, addr);
180 	}
181 }
182 
183 /* When a static FDB entry is deleted, the HW address from that entry is
184  * also removed from the bridge private HW address list and updates all
185  * the ports with needed information.
186  * Called under RTNL.
187  */
188 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
189 {
190 	struct net_bridge_port *p;
191 
192 	ASSERT_RTNL();
193 
194 	list_for_each_entry(p, &br->port_list, list) {
195 		if (!br_promisc_port(p))
196 			dev_uc_del(p->dev, addr);
197 	}
198 }
199 
200 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f,
201 		       bool swdev_notify)
202 {
203 	trace_fdb_delete(br, f);
204 
205 	if (f->is_static)
206 		fdb_del_hw_addr(br, f->key.addr.addr);
207 
208 	hlist_del_init_rcu(&f->fdb_node);
209 	rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode,
210 			       br_fdb_rht_params);
211 	fdb_notify(br, f, RTM_DELNEIGH, swdev_notify);
212 	call_rcu(&f->rcu, fdb_rcu_free);
213 }
214 
215 /* Delete a local entry if no other port had the same address. */
216 static void fdb_delete_local(struct net_bridge *br,
217 			     const struct net_bridge_port *p,
218 			     struct net_bridge_fdb_entry *f)
219 {
220 	const unsigned char *addr = f->key.addr.addr;
221 	struct net_bridge_vlan_group *vg;
222 	const struct net_bridge_vlan *v;
223 	struct net_bridge_port *op;
224 	u16 vid = f->key.vlan_id;
225 
226 	/* Maybe another port has same hw addr? */
227 	list_for_each_entry(op, &br->port_list, list) {
228 		vg = nbp_vlan_group(op);
229 		if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
230 		    (!vid || br_vlan_find(vg, vid))) {
231 			f->dst = op;
232 			f->added_by_user = 0;
233 			return;
234 		}
235 	}
236 
237 	vg = br_vlan_group(br);
238 	v = br_vlan_find(vg, vid);
239 	/* Maybe bridge device has same hw addr? */
240 	if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
241 	    (!vid || (v && br_vlan_should_use(v)))) {
242 		f->dst = NULL;
243 		f->added_by_user = 0;
244 		return;
245 	}
246 
247 	fdb_delete(br, f, true);
248 }
249 
250 void br_fdb_find_delete_local(struct net_bridge *br,
251 			      const struct net_bridge_port *p,
252 			      const unsigned char *addr, u16 vid)
253 {
254 	struct net_bridge_fdb_entry *f;
255 
256 	spin_lock_bh(&br->hash_lock);
257 	f = br_fdb_find(br, addr, vid);
258 	if (f && f->is_local && !f->added_by_user && f->dst == p)
259 		fdb_delete_local(br, p, f);
260 	spin_unlock_bh(&br->hash_lock);
261 }
262 
263 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
264 {
265 	struct net_bridge_vlan_group *vg;
266 	struct net_bridge_fdb_entry *f;
267 	struct net_bridge *br = p->br;
268 	struct net_bridge_vlan *v;
269 
270 	spin_lock_bh(&br->hash_lock);
271 	vg = nbp_vlan_group(p);
272 	hlist_for_each_entry(f, &br->fdb_list, fdb_node) {
273 		if (f->dst == p && f->is_local && !f->added_by_user) {
274 			/* delete old one */
275 			fdb_delete_local(br, p, f);
276 
277 			/* if this port has no vlan information
278 			 * configured, we can safely be done at
279 			 * this point.
280 			 */
281 			if (!vg || !vg->num_vlans)
282 				goto insert;
283 		}
284 	}
285 
286 insert:
287 	/* insert new address,  may fail if invalid address or dup. */
288 	fdb_insert(br, p, newaddr, 0);
289 
290 	if (!vg || !vg->num_vlans)
291 		goto done;
292 
293 	/* Now add entries for every VLAN configured on the port.
294 	 * This function runs under RTNL so the bitmap will not change
295 	 * from under us.
296 	 */
297 	list_for_each_entry(v, &vg->vlan_list, vlist)
298 		fdb_insert(br, p, newaddr, v->vid);
299 
300 done:
301 	spin_unlock_bh(&br->hash_lock);
302 }
303 
304 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
305 {
306 	struct net_bridge_vlan_group *vg;
307 	struct net_bridge_fdb_entry *f;
308 	struct net_bridge_vlan *v;
309 
310 	spin_lock_bh(&br->hash_lock);
311 
312 	/* If old entry was unassociated with any port, then delete it. */
313 	f = br_fdb_find(br, br->dev->dev_addr, 0);
314 	if (f && f->is_local && !f->dst && !f->added_by_user)
315 		fdb_delete_local(br, NULL, f);
316 
317 	fdb_insert(br, NULL, newaddr, 0);
318 	vg = br_vlan_group(br);
319 	if (!vg || !vg->num_vlans)
320 		goto out;
321 	/* Now remove and add entries for every VLAN configured on the
322 	 * bridge.  This function runs under RTNL so the bitmap will not
323 	 * change from under us.
324 	 */
325 	list_for_each_entry(v, &vg->vlan_list, vlist) {
326 		if (!br_vlan_should_use(v))
327 			continue;
328 		f = br_fdb_find(br, br->dev->dev_addr, v->vid);
329 		if (f && f->is_local && !f->dst && !f->added_by_user)
330 			fdb_delete_local(br, NULL, f);
331 		fdb_insert(br, NULL, newaddr, v->vid);
332 	}
333 out:
334 	spin_unlock_bh(&br->hash_lock);
335 }
336 
337 void br_fdb_cleanup(struct work_struct *work)
338 {
339 	struct net_bridge *br = container_of(work, struct net_bridge,
340 					     gc_work.work);
341 	struct net_bridge_fdb_entry *f = NULL;
342 	unsigned long delay = hold_time(br);
343 	unsigned long work_delay = delay;
344 	unsigned long now = jiffies;
345 
346 	/* this part is tricky, in order to avoid blocking learning and
347 	 * consequently forwarding, we rely on rcu to delete objects with
348 	 * delayed freeing allowing us to continue traversing
349 	 */
350 	rcu_read_lock();
351 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
352 		unsigned long this_timer;
353 
354 		if (f->is_static || f->added_by_external_learn)
355 			continue;
356 		this_timer = f->updated + delay;
357 		if (time_after(this_timer, now)) {
358 			work_delay = min(work_delay, this_timer - now);
359 		} else {
360 			spin_lock_bh(&br->hash_lock);
361 			if (!hlist_unhashed(&f->fdb_node))
362 				fdb_delete(br, f, true);
363 			spin_unlock_bh(&br->hash_lock);
364 		}
365 	}
366 	rcu_read_unlock();
367 
368 	/* Cleanup minimum 10 milliseconds apart */
369 	work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
370 	mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
371 }
372 
373 /* Completely flush all dynamic entries in forwarding database.*/
374 void br_fdb_flush(struct net_bridge *br)
375 {
376 	struct net_bridge_fdb_entry *f;
377 	struct hlist_node *tmp;
378 
379 	spin_lock_bh(&br->hash_lock);
380 	hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
381 		if (!f->is_static)
382 			fdb_delete(br, f, true);
383 	}
384 	spin_unlock_bh(&br->hash_lock);
385 }
386 
387 /* Flush all entries referring to a specific port.
388  * if do_all is set also flush static entries
389  * if vid is set delete all entries that match the vlan_id
390  */
391 void br_fdb_delete_by_port(struct net_bridge *br,
392 			   const struct net_bridge_port *p,
393 			   u16 vid,
394 			   int do_all)
395 {
396 	struct net_bridge_fdb_entry *f;
397 	struct hlist_node *tmp;
398 
399 	spin_lock_bh(&br->hash_lock);
400 	hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
401 		if (f->dst != p)
402 			continue;
403 
404 		if (!do_all)
405 			if (f->is_static || (vid && f->key.vlan_id != vid))
406 				continue;
407 
408 		if (f->is_local)
409 			fdb_delete_local(br, p, f);
410 		else
411 			fdb_delete(br, f, true);
412 	}
413 	spin_unlock_bh(&br->hash_lock);
414 }
415 
416 #if IS_ENABLED(CONFIG_ATM_LANE)
417 /* Interface used by ATM LANE hook to test
418  * if an addr is on some other bridge port */
419 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
420 {
421 	struct net_bridge_fdb_entry *fdb;
422 	struct net_bridge_port *port;
423 	int ret;
424 
425 	rcu_read_lock();
426 	port = br_port_get_rcu(dev);
427 	if (!port)
428 		ret = 0;
429 	else {
430 		fdb = br_fdb_find_rcu(port->br, addr, 0);
431 		ret = fdb && fdb->dst && fdb->dst->dev != dev &&
432 			fdb->dst->state == BR_STATE_FORWARDING;
433 	}
434 	rcu_read_unlock();
435 
436 	return ret;
437 }
438 #endif /* CONFIG_ATM_LANE */
439 
440 /*
441  * Fill buffer with forwarding table records in
442  * the API format.
443  */
444 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
445 		   unsigned long maxnum, unsigned long skip)
446 {
447 	struct net_bridge_fdb_entry *f;
448 	struct __fdb_entry *fe = buf;
449 	int num = 0;
450 
451 	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
452 
453 	rcu_read_lock();
454 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
455 		if (num >= maxnum)
456 			break;
457 
458 		if (has_expired(br, f))
459 			continue;
460 
461 		/* ignore pseudo entry for local MAC address */
462 		if (!f->dst)
463 			continue;
464 
465 		if (skip) {
466 			--skip;
467 			continue;
468 		}
469 
470 		/* convert from internal format to API */
471 		memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN);
472 
473 		/* due to ABI compat need to split into hi/lo */
474 		fe->port_no = f->dst->port_no;
475 		fe->port_hi = f->dst->port_no >> 8;
476 
477 		fe->is_local = f->is_local;
478 		if (!f->is_static)
479 			fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
480 		++fe;
481 		++num;
482 	}
483 	rcu_read_unlock();
484 
485 	return num;
486 }
487 
488 static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br,
489 					       struct net_bridge_port *source,
490 					       const unsigned char *addr,
491 					       __u16 vid,
492 					       unsigned char is_local,
493 					       unsigned char is_static)
494 {
495 	struct net_bridge_fdb_entry *fdb;
496 
497 	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
498 	if (fdb) {
499 		memcpy(fdb->key.addr.addr, addr, ETH_ALEN);
500 		fdb->dst = source;
501 		fdb->key.vlan_id = vid;
502 		fdb->is_local = is_local;
503 		fdb->is_static = is_static;
504 		fdb->added_by_user = 0;
505 		fdb->added_by_external_learn = 0;
506 		fdb->offloaded = 0;
507 		fdb->is_sticky = 0;
508 		fdb->updated = fdb->used = jiffies;
509 		if (rhashtable_lookup_insert_fast(&br->fdb_hash_tbl,
510 						  &fdb->rhnode,
511 						  br_fdb_rht_params)) {
512 			kmem_cache_free(br_fdb_cache, fdb);
513 			fdb = NULL;
514 		} else {
515 			hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list);
516 		}
517 	}
518 	return fdb;
519 }
520 
521 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
522 		  const unsigned char *addr, u16 vid)
523 {
524 	struct net_bridge_fdb_entry *fdb;
525 
526 	if (!is_valid_ether_addr(addr))
527 		return -EINVAL;
528 
529 	fdb = br_fdb_find(br, addr, vid);
530 	if (fdb) {
531 		/* it is okay to have multiple ports with same
532 		 * address, just use the first one.
533 		 */
534 		if (fdb->is_local)
535 			return 0;
536 		br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
537 		       source ? source->dev->name : br->dev->name, addr, vid);
538 		fdb_delete(br, fdb, true);
539 	}
540 
541 	fdb = fdb_create(br, source, addr, vid, 1, 1);
542 	if (!fdb)
543 		return -ENOMEM;
544 
545 	fdb_add_hw_addr(br, addr);
546 	fdb_notify(br, fdb, RTM_NEWNEIGH, true);
547 	return 0;
548 }
549 
550 /* Add entry for local address of interface */
551 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
552 		  const unsigned char *addr, u16 vid)
553 {
554 	int ret;
555 
556 	spin_lock_bh(&br->hash_lock);
557 	ret = fdb_insert(br, source, addr, vid);
558 	spin_unlock_bh(&br->hash_lock);
559 	return ret;
560 }
561 
562 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
563 		   const unsigned char *addr, u16 vid, bool added_by_user)
564 {
565 	struct net_bridge_fdb_entry *fdb;
566 	bool fdb_modified = false;
567 
568 	/* some users want to always flood. */
569 	if (hold_time(br) == 0)
570 		return;
571 
572 	/* ignore packets unless we are using this port */
573 	if (!(source->state == BR_STATE_LEARNING ||
574 	      source->state == BR_STATE_FORWARDING))
575 		return;
576 
577 	fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
578 	if (likely(fdb)) {
579 		/* attempt to update an entry for a local interface */
580 		if (unlikely(fdb->is_local)) {
581 			if (net_ratelimit())
582 				br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
583 					source->dev->name, addr, vid);
584 		} else {
585 			unsigned long now = jiffies;
586 
587 			/* fastpath: update of existing entry */
588 			if (unlikely(source != fdb->dst && !fdb->is_sticky)) {
589 				fdb->dst = source;
590 				fdb_modified = true;
591 				/* Take over HW learned entry */
592 				if (unlikely(fdb->added_by_external_learn))
593 					fdb->added_by_external_learn = 0;
594 			}
595 			if (now != fdb->updated)
596 				fdb->updated = now;
597 			if (unlikely(added_by_user))
598 				fdb->added_by_user = 1;
599 			if (unlikely(fdb_modified)) {
600 				trace_br_fdb_update(br, source, addr, vid, added_by_user);
601 				fdb_notify(br, fdb, RTM_NEWNEIGH, true);
602 			}
603 		}
604 	} else {
605 		spin_lock(&br->hash_lock);
606 		fdb = fdb_create(br, source, addr, vid, 0, 0);
607 		if (fdb) {
608 			if (unlikely(added_by_user))
609 				fdb->added_by_user = 1;
610 			trace_br_fdb_update(br, source, addr, vid,
611 					    added_by_user);
612 			fdb_notify(br, fdb, RTM_NEWNEIGH, true);
613 		}
614 		/* else  we lose race and someone else inserts
615 		 * it first, don't bother updating
616 		 */
617 		spin_unlock(&br->hash_lock);
618 	}
619 }
620 
621 static int fdb_to_nud(const struct net_bridge *br,
622 		      const struct net_bridge_fdb_entry *fdb)
623 {
624 	if (fdb->is_local)
625 		return NUD_PERMANENT;
626 	else if (fdb->is_static)
627 		return NUD_NOARP;
628 	else if (has_expired(br, fdb))
629 		return NUD_STALE;
630 	else
631 		return NUD_REACHABLE;
632 }
633 
634 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
635 			 const struct net_bridge_fdb_entry *fdb,
636 			 u32 portid, u32 seq, int type, unsigned int flags)
637 {
638 	unsigned long now = jiffies;
639 	struct nda_cacheinfo ci;
640 	struct nlmsghdr *nlh;
641 	struct ndmsg *ndm;
642 
643 	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
644 	if (nlh == NULL)
645 		return -EMSGSIZE;
646 
647 	ndm = nlmsg_data(nlh);
648 	ndm->ndm_family	 = AF_BRIDGE;
649 	ndm->ndm_pad1    = 0;
650 	ndm->ndm_pad2    = 0;
651 	ndm->ndm_flags	 = 0;
652 	ndm->ndm_type	 = 0;
653 	ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
654 	ndm->ndm_state   = fdb_to_nud(br, fdb);
655 
656 	if (fdb->offloaded)
657 		ndm->ndm_flags |= NTF_OFFLOADED;
658 	if (fdb->added_by_external_learn)
659 		ndm->ndm_flags |= NTF_EXT_LEARNED;
660 	if (fdb->is_sticky)
661 		ndm->ndm_flags |= NTF_STICKY;
662 
663 	if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr))
664 		goto nla_put_failure;
665 	if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
666 		goto nla_put_failure;
667 	ci.ndm_used	 = jiffies_to_clock_t(now - fdb->used);
668 	ci.ndm_confirmed = 0;
669 	ci.ndm_updated	 = jiffies_to_clock_t(now - fdb->updated);
670 	ci.ndm_refcnt	 = 0;
671 	if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
672 		goto nla_put_failure;
673 
674 	if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16),
675 					&fdb->key.vlan_id))
676 		goto nla_put_failure;
677 
678 	nlmsg_end(skb, nlh);
679 	return 0;
680 
681 nla_put_failure:
682 	nlmsg_cancel(skb, nlh);
683 	return -EMSGSIZE;
684 }
685 
686 static inline size_t fdb_nlmsg_size(void)
687 {
688 	return NLMSG_ALIGN(sizeof(struct ndmsg))
689 		+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
690 		+ nla_total_size(sizeof(u32)) /* NDA_MASTER */
691 		+ nla_total_size(sizeof(u16)) /* NDA_VLAN */
692 		+ nla_total_size(sizeof(struct nda_cacheinfo));
693 }
694 
695 static void fdb_notify(struct net_bridge *br,
696 		       const struct net_bridge_fdb_entry *fdb, int type,
697 		       bool swdev_notify)
698 {
699 	struct net *net = dev_net(br->dev);
700 	struct sk_buff *skb;
701 	int err = -ENOBUFS;
702 
703 	if (swdev_notify)
704 		br_switchdev_fdb_notify(fdb, type);
705 
706 	skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
707 	if (skb == NULL)
708 		goto errout;
709 
710 	err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
711 	if (err < 0) {
712 		/* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
713 		WARN_ON(err == -EMSGSIZE);
714 		kfree_skb(skb);
715 		goto errout;
716 	}
717 	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
718 	return;
719 errout:
720 	rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
721 }
722 
723 /* Dump information about entries, in response to GETNEIGH */
724 int br_fdb_dump(struct sk_buff *skb,
725 		struct netlink_callback *cb,
726 		struct net_device *dev,
727 		struct net_device *filter_dev,
728 		int *idx)
729 {
730 	struct net_bridge *br = netdev_priv(dev);
731 	struct net_bridge_fdb_entry *f;
732 	int err = 0;
733 
734 	if (!(dev->priv_flags & IFF_EBRIDGE))
735 		return err;
736 
737 	if (!filter_dev) {
738 		err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
739 		if (err < 0)
740 			return err;
741 	}
742 
743 	rcu_read_lock();
744 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
745 		if (*idx < cb->args[2])
746 			goto skip;
747 		if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
748 			if (filter_dev != dev)
749 				goto skip;
750 			/* !f->dst is a special case for bridge
751 			 * It means the MAC belongs to the bridge
752 			 * Therefore need a little more filtering
753 			 * we only want to dump the !f->dst case
754 			 */
755 			if (f->dst)
756 				goto skip;
757 		}
758 		if (!filter_dev && f->dst)
759 			goto skip;
760 
761 		err = fdb_fill_info(skb, br, f,
762 				    NETLINK_CB(cb->skb).portid,
763 				    cb->nlh->nlmsg_seq,
764 				    RTM_NEWNEIGH,
765 				    NLM_F_MULTI);
766 		if (err < 0)
767 			break;
768 skip:
769 		*idx += 1;
770 	}
771 	rcu_read_unlock();
772 
773 	return err;
774 }
775 
776 int br_fdb_get(struct sk_buff *skb,
777 	       struct nlattr *tb[],
778 	       struct net_device *dev,
779 	       const unsigned char *addr,
780 	       u16 vid, u32 portid, u32 seq,
781 	       struct netlink_ext_ack *extack)
782 {
783 	struct net_bridge *br = netdev_priv(dev);
784 	struct net_bridge_fdb_entry *f;
785 	int err = 0;
786 
787 	rcu_read_lock();
788 	f = br_fdb_find_rcu(br, addr, vid);
789 	if (!f) {
790 		NL_SET_ERR_MSG(extack, "Fdb entry not found");
791 		err = -ENOENT;
792 		goto errout;
793 	}
794 
795 	err = fdb_fill_info(skb, br, f, portid, seq,
796 			    RTM_NEWNEIGH, 0);
797 errout:
798 	rcu_read_unlock();
799 	return err;
800 }
801 
802 /* Update (create or replace) forwarding database entry */
803 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
804 			 const u8 *addr, u16 state, u16 flags, u16 vid,
805 			 u8 ndm_flags)
806 {
807 	u8 is_sticky = !!(ndm_flags & NTF_STICKY);
808 	struct net_bridge_fdb_entry *fdb;
809 	bool modified = false;
810 
811 	/* If the port cannot learn allow only local and static entries */
812 	if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
813 	    !(source->state == BR_STATE_LEARNING ||
814 	      source->state == BR_STATE_FORWARDING))
815 		return -EPERM;
816 
817 	if (!source && !(state & NUD_PERMANENT)) {
818 		pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
819 			br->dev->name);
820 		return -EINVAL;
821 	}
822 
823 	if (is_sticky && (state & NUD_PERMANENT))
824 		return -EINVAL;
825 
826 	fdb = br_fdb_find(br, addr, vid);
827 	if (fdb == NULL) {
828 		if (!(flags & NLM_F_CREATE))
829 			return -ENOENT;
830 
831 		fdb = fdb_create(br, source, addr, vid, 0, 0);
832 		if (!fdb)
833 			return -ENOMEM;
834 
835 		modified = true;
836 	} else {
837 		if (flags & NLM_F_EXCL)
838 			return -EEXIST;
839 
840 		if (fdb->dst != source) {
841 			fdb->dst = source;
842 			modified = true;
843 		}
844 	}
845 
846 	if (fdb_to_nud(br, fdb) != state) {
847 		if (state & NUD_PERMANENT) {
848 			fdb->is_local = 1;
849 			if (!fdb->is_static) {
850 				fdb->is_static = 1;
851 				fdb_add_hw_addr(br, addr);
852 			}
853 		} else if (state & NUD_NOARP) {
854 			fdb->is_local = 0;
855 			if (!fdb->is_static) {
856 				fdb->is_static = 1;
857 				fdb_add_hw_addr(br, addr);
858 			}
859 		} else {
860 			fdb->is_local = 0;
861 			if (fdb->is_static) {
862 				fdb->is_static = 0;
863 				fdb_del_hw_addr(br, addr);
864 			}
865 		}
866 
867 		modified = true;
868 	}
869 
870 	if (is_sticky != fdb->is_sticky) {
871 		fdb->is_sticky = is_sticky;
872 		modified = true;
873 	}
874 
875 	fdb->added_by_user = 1;
876 
877 	fdb->used = jiffies;
878 	if (modified) {
879 		fdb->updated = jiffies;
880 		fdb_notify(br, fdb, RTM_NEWNEIGH, true);
881 	}
882 
883 	return 0;
884 }
885 
886 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
887 			struct net_bridge_port *p, const unsigned char *addr,
888 			u16 nlh_flags, u16 vid)
889 {
890 	int err = 0;
891 
892 	if (ndm->ndm_flags & NTF_USE) {
893 		if (!p) {
894 			pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
895 				br->dev->name);
896 			return -EINVAL;
897 		}
898 		local_bh_disable();
899 		rcu_read_lock();
900 		br_fdb_update(br, p, addr, vid, true);
901 		rcu_read_unlock();
902 		local_bh_enable();
903 	} else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
904 		err = br_fdb_external_learn_add(br, p, addr, vid, true);
905 	} else {
906 		spin_lock_bh(&br->hash_lock);
907 		err = fdb_add_entry(br, p, addr, ndm->ndm_state,
908 				    nlh_flags, vid, ndm->ndm_flags);
909 		spin_unlock_bh(&br->hash_lock);
910 	}
911 
912 	return err;
913 }
914 
915 /* Add new permanent fdb entry with RTM_NEWNEIGH */
916 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
917 	       struct net_device *dev,
918 	       const unsigned char *addr, u16 vid, u16 nlh_flags,
919 	       struct netlink_ext_ack *extack)
920 {
921 	struct net_bridge_vlan_group *vg;
922 	struct net_bridge_port *p = NULL;
923 	struct net_bridge_vlan *v;
924 	struct net_bridge *br = NULL;
925 	int err = 0;
926 
927 	trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);
928 
929 	if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
930 		pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
931 		return -EINVAL;
932 	}
933 
934 	if (is_zero_ether_addr(addr)) {
935 		pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
936 		return -EINVAL;
937 	}
938 
939 	if (dev->priv_flags & IFF_EBRIDGE) {
940 		br = netdev_priv(dev);
941 		vg = br_vlan_group(br);
942 	} else {
943 		p = br_port_get_rtnl(dev);
944 		if (!p) {
945 			pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
946 				dev->name);
947 			return -EINVAL;
948 		}
949 		br = p->br;
950 		vg = nbp_vlan_group(p);
951 	}
952 
953 	if (vid) {
954 		v = br_vlan_find(vg, vid);
955 		if (!v || !br_vlan_should_use(v)) {
956 			pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
957 			return -EINVAL;
958 		}
959 
960 		/* VID was specified, so use it. */
961 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
962 	} else {
963 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
964 		if (err || !vg || !vg->num_vlans)
965 			goto out;
966 
967 		/* We have vlans configured on this port and user didn't
968 		 * specify a VLAN.  To be nice, add/update entry for every
969 		 * vlan on this port.
970 		 */
971 		list_for_each_entry(v, &vg->vlan_list, vlist) {
972 			if (!br_vlan_should_use(v))
973 				continue;
974 			err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
975 			if (err)
976 				goto out;
977 		}
978 	}
979 
980 out:
981 	return err;
982 }
983 
984 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
985 				       const struct net_bridge_port *p,
986 				       const u8 *addr, u16 vlan)
987 {
988 	struct net_bridge_fdb_entry *fdb;
989 
990 	fdb = br_fdb_find(br, addr, vlan);
991 	if (!fdb || fdb->dst != p)
992 		return -ENOENT;
993 
994 	fdb_delete(br, fdb, true);
995 
996 	return 0;
997 }
998 
999 static int __br_fdb_delete(struct net_bridge *br,
1000 			   const struct net_bridge_port *p,
1001 			   const unsigned char *addr, u16 vid)
1002 {
1003 	int err;
1004 
1005 	spin_lock_bh(&br->hash_lock);
1006 	err = fdb_delete_by_addr_and_port(br, p, addr, vid);
1007 	spin_unlock_bh(&br->hash_lock);
1008 
1009 	return err;
1010 }
1011 
1012 /* Remove neighbor entry with RTM_DELNEIGH */
1013 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
1014 		  struct net_device *dev,
1015 		  const unsigned char *addr, u16 vid)
1016 {
1017 	struct net_bridge_vlan_group *vg;
1018 	struct net_bridge_port *p = NULL;
1019 	struct net_bridge_vlan *v;
1020 	struct net_bridge *br;
1021 	int err;
1022 
1023 	if (dev->priv_flags & IFF_EBRIDGE) {
1024 		br = netdev_priv(dev);
1025 		vg = br_vlan_group(br);
1026 	} else {
1027 		p = br_port_get_rtnl(dev);
1028 		if (!p) {
1029 			pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1030 				dev->name);
1031 			return -EINVAL;
1032 		}
1033 		vg = nbp_vlan_group(p);
1034 		br = p->br;
1035 	}
1036 
1037 	if (vid) {
1038 		v = br_vlan_find(vg, vid);
1039 		if (!v) {
1040 			pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1041 			return -EINVAL;
1042 		}
1043 
1044 		err = __br_fdb_delete(br, p, addr, vid);
1045 	} else {
1046 		err = -ENOENT;
1047 		err &= __br_fdb_delete(br, p, addr, 0);
1048 		if (!vg || !vg->num_vlans)
1049 			return err;
1050 
1051 		list_for_each_entry(v, &vg->vlan_list, vlist) {
1052 			if (!br_vlan_should_use(v))
1053 				continue;
1054 			err &= __br_fdb_delete(br, p, addr, v->vid);
1055 		}
1056 	}
1057 
1058 	return err;
1059 }
1060 
1061 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1062 {
1063 	struct net_bridge_fdb_entry *f, *tmp;
1064 	int err = 0;
1065 
1066 	ASSERT_RTNL();
1067 
1068 	/* the key here is that static entries change only under rtnl */
1069 	rcu_read_lock();
1070 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1071 		/* We only care for static entries */
1072 		if (!f->is_static)
1073 			continue;
1074 		err = dev_uc_add(p->dev, f->key.addr.addr);
1075 		if (err)
1076 			goto rollback;
1077 	}
1078 done:
1079 	rcu_read_unlock();
1080 
1081 	return err;
1082 
1083 rollback:
1084 	hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) {
1085 		/* We only care for static entries */
1086 		if (!tmp->is_static)
1087 			continue;
1088 		if (tmp == f)
1089 			break;
1090 		dev_uc_del(p->dev, tmp->key.addr.addr);
1091 	}
1092 
1093 	goto done;
1094 }
1095 
1096 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1097 {
1098 	struct net_bridge_fdb_entry *f;
1099 
1100 	ASSERT_RTNL();
1101 
1102 	rcu_read_lock();
1103 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1104 		/* We only care for static entries */
1105 		if (!f->is_static)
1106 			continue;
1107 
1108 		dev_uc_del(p->dev, f->key.addr.addr);
1109 	}
1110 	rcu_read_unlock();
1111 }
1112 
1113 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1114 			      const unsigned char *addr, u16 vid,
1115 			      bool swdev_notify)
1116 {
1117 	struct net_bridge_fdb_entry *fdb;
1118 	bool modified = false;
1119 	int err = 0;
1120 
1121 	trace_br_fdb_external_learn_add(br, p, addr, vid);
1122 
1123 	spin_lock_bh(&br->hash_lock);
1124 
1125 	fdb = br_fdb_find(br, addr, vid);
1126 	if (!fdb) {
1127 		fdb = fdb_create(br, p, addr, vid, 0, 0);
1128 		if (!fdb) {
1129 			err = -ENOMEM;
1130 			goto err_unlock;
1131 		}
1132 		if (swdev_notify)
1133 			fdb->added_by_user = 1;
1134 		fdb->added_by_external_learn = 1;
1135 		fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1136 	} else {
1137 		fdb->updated = jiffies;
1138 
1139 		if (fdb->dst != p) {
1140 			fdb->dst = p;
1141 			modified = true;
1142 		}
1143 
1144 		if (fdb->added_by_external_learn) {
1145 			/* Refresh entry */
1146 			fdb->used = jiffies;
1147 		} else if (!fdb->added_by_user) {
1148 			/* Take over SW learned entry */
1149 			fdb->added_by_external_learn = 1;
1150 			modified = true;
1151 		}
1152 
1153 		if (swdev_notify)
1154 			fdb->added_by_user = 1;
1155 
1156 		if (modified)
1157 			fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1158 	}
1159 
1160 err_unlock:
1161 	spin_unlock_bh(&br->hash_lock);
1162 
1163 	return err;
1164 }
1165 
1166 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1167 			      const unsigned char *addr, u16 vid,
1168 			      bool swdev_notify)
1169 {
1170 	struct net_bridge_fdb_entry *fdb;
1171 	int err = 0;
1172 
1173 	spin_lock_bh(&br->hash_lock);
1174 
1175 	fdb = br_fdb_find(br, addr, vid);
1176 	if (fdb && fdb->added_by_external_learn)
1177 		fdb_delete(br, fdb, swdev_notify);
1178 	else
1179 		err = -ENOENT;
1180 
1181 	spin_unlock_bh(&br->hash_lock);
1182 
1183 	return err;
1184 }
1185 
1186 void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1187 			  const unsigned char *addr, u16 vid, bool offloaded)
1188 {
1189 	struct net_bridge_fdb_entry *fdb;
1190 
1191 	spin_lock_bh(&br->hash_lock);
1192 
1193 	fdb = br_fdb_find(br, addr, vid);
1194 	if (fdb)
1195 		fdb->offloaded = offloaded;
1196 
1197 	spin_unlock_bh(&br->hash_lock);
1198 }
1199 
1200 void br_fdb_clear_offload(const struct net_device *dev, u16 vid)
1201 {
1202 	struct net_bridge_fdb_entry *f;
1203 	struct net_bridge_port *p;
1204 
1205 	ASSERT_RTNL();
1206 
1207 	p = br_port_get_rtnl(dev);
1208 	if (!p)
1209 		return;
1210 
1211 	spin_lock_bh(&p->br->hash_lock);
1212 	hlist_for_each_entry(f, &p->br->fdb_list, fdb_node) {
1213 		if (f->dst == p && f->key.vlan_id == vid)
1214 			f->offloaded = 0;
1215 	}
1216 	spin_unlock_bh(&p->br->hash_lock);
1217 }
1218 EXPORT_SYMBOL_GPL(br_fdb_clear_offload);
1219