xref: /openbmc/linux/net/bridge/br_fdb.c (revision f7c35abe)
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 int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
32 		      const unsigned char *addr, u16 vid);
33 static void fdb_notify(struct net_bridge *br,
34 		       const struct net_bridge_fdb_entry *, int);
35 
36 static u32 fdb_salt __read_mostly;
37 
38 int __init br_fdb_init(void)
39 {
40 	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
41 					 sizeof(struct net_bridge_fdb_entry),
42 					 0,
43 					 SLAB_HWCACHE_ALIGN, NULL);
44 	if (!br_fdb_cache)
45 		return -ENOMEM;
46 
47 	get_random_bytes(&fdb_salt, sizeof(fdb_salt));
48 	return 0;
49 }
50 
51 void br_fdb_fini(void)
52 {
53 	kmem_cache_destroy(br_fdb_cache);
54 }
55 
56 
57 /* if topology_changing then use forward_delay (default 15 sec)
58  * otherwise keep longer (default 5 minutes)
59  */
60 static inline unsigned long hold_time(const struct net_bridge *br)
61 {
62 	return br->topology_change ? br->forward_delay : br->ageing_time;
63 }
64 
65 static inline int has_expired(const struct net_bridge *br,
66 				  const struct net_bridge_fdb_entry *fdb)
67 {
68 	return !fdb->is_static && !fdb->added_by_external_learn &&
69 		time_before_eq(fdb->updated + hold_time(br), jiffies);
70 }
71 
72 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
73 {
74 	/* use 1 byte of OUI and 3 bytes of NIC */
75 	u32 key = get_unaligned((u32 *)(mac + 2));
76 	return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
77 }
78 
79 static void fdb_rcu_free(struct rcu_head *head)
80 {
81 	struct net_bridge_fdb_entry *ent
82 		= container_of(head, struct net_bridge_fdb_entry, rcu);
83 	kmem_cache_free(br_fdb_cache, ent);
84 }
85 
86 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
87 						 const unsigned char *addr,
88 						 __u16 vid)
89 {
90 	struct net_bridge_fdb_entry *f;
91 
92 	WARN_ON_ONCE(!rcu_read_lock_held());
93 
94 	hlist_for_each_entry_rcu(f, head, hlist)
95 		if (ether_addr_equal(f->addr.addr, addr) && f->vlan_id == vid)
96 			break;
97 
98 	return f;
99 }
100 
101 /* requires bridge hash_lock */
102 static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
103 						const unsigned char *addr,
104 						__u16 vid)
105 {
106 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
107 	struct net_bridge_fdb_entry *fdb;
108 
109 	lockdep_assert_held_once(&br->hash_lock);
110 
111 	rcu_read_lock();
112 	fdb = fdb_find_rcu(head, addr, vid);
113 	rcu_read_unlock();
114 
115 	return fdb;
116 }
117 
118 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
119 					     const unsigned char *addr,
120 					     __u16 vid)
121 {
122 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
123 
124 	return fdb_find_rcu(head, addr, vid);
125 }
126 
127 /* When a static FDB entry is added, the mac address from the entry is
128  * added to the bridge private HW address list and all required ports
129  * are then updated with the new information.
130  * Called under RTNL.
131  */
132 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
133 {
134 	int err;
135 	struct net_bridge_port *p;
136 
137 	ASSERT_RTNL();
138 
139 	list_for_each_entry(p, &br->port_list, list) {
140 		if (!br_promisc_port(p)) {
141 			err = dev_uc_add(p->dev, addr);
142 			if (err)
143 				goto undo;
144 		}
145 	}
146 
147 	return;
148 undo:
149 	list_for_each_entry_continue_reverse(p, &br->port_list, list) {
150 		if (!br_promisc_port(p))
151 			dev_uc_del(p->dev, addr);
152 	}
153 }
154 
155 /* When a static FDB entry is deleted, the HW address from that entry is
156  * also removed from the bridge private HW address list and updates all
157  * the ports with needed information.
158  * Called under RTNL.
159  */
160 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
161 {
162 	struct net_bridge_port *p;
163 
164 	ASSERT_RTNL();
165 
166 	list_for_each_entry(p, &br->port_list, list) {
167 		if (!br_promisc_port(p))
168 			dev_uc_del(p->dev, addr);
169 	}
170 }
171 
172 static void fdb_del_external_learn(struct net_bridge_fdb_entry *f)
173 {
174 	struct switchdev_obj_port_fdb fdb = {
175 		.obj = {
176 			.orig_dev = f->dst->dev,
177 			.id = SWITCHDEV_OBJ_ID_PORT_FDB,
178 			.flags = SWITCHDEV_F_DEFER,
179 		},
180 		.vid = f->vlan_id,
181 	};
182 
183 	ether_addr_copy(fdb.addr, f->addr.addr);
184 	switchdev_port_obj_del(f->dst->dev, &fdb.obj);
185 }
186 
187 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
188 {
189 	if (f->is_static)
190 		fdb_del_hw_addr(br, f->addr.addr);
191 
192 	if (f->added_by_external_learn)
193 		fdb_del_external_learn(f);
194 
195 	hlist_del_init_rcu(&f->hlist);
196 	fdb_notify(br, f, RTM_DELNEIGH);
197 	call_rcu(&f->rcu, fdb_rcu_free);
198 }
199 
200 /* Delete a local entry if no other port had the same address. */
201 static void fdb_delete_local(struct net_bridge *br,
202 			     const struct net_bridge_port *p,
203 			     struct net_bridge_fdb_entry *f)
204 {
205 	const unsigned char *addr = f->addr.addr;
206 	struct net_bridge_vlan_group *vg;
207 	const struct net_bridge_vlan *v;
208 	struct net_bridge_port *op;
209 	u16 vid = f->vlan_id;
210 
211 	/* Maybe another port has same hw addr? */
212 	list_for_each_entry(op, &br->port_list, list) {
213 		vg = nbp_vlan_group(op);
214 		if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
215 		    (!vid || br_vlan_find(vg, vid))) {
216 			f->dst = op;
217 			f->added_by_user = 0;
218 			return;
219 		}
220 	}
221 
222 	vg = br_vlan_group(br);
223 	v = br_vlan_find(vg, vid);
224 	/* Maybe bridge device has same hw addr? */
225 	if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
226 	    (!vid || (v && br_vlan_should_use(v)))) {
227 		f->dst = NULL;
228 		f->added_by_user = 0;
229 		return;
230 	}
231 
232 	fdb_delete(br, f);
233 }
234 
235 void br_fdb_find_delete_local(struct net_bridge *br,
236 			      const struct net_bridge_port *p,
237 			      const unsigned char *addr, u16 vid)
238 {
239 	struct net_bridge_fdb_entry *f;
240 
241 	spin_lock_bh(&br->hash_lock);
242 	f = br_fdb_find(br, addr, vid);
243 	if (f && f->is_local && !f->added_by_user && f->dst == p)
244 		fdb_delete_local(br, p, f);
245 	spin_unlock_bh(&br->hash_lock);
246 }
247 
248 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
249 {
250 	struct net_bridge_vlan_group *vg;
251 	struct net_bridge *br = p->br;
252 	struct net_bridge_vlan *v;
253 	int i;
254 
255 	spin_lock_bh(&br->hash_lock);
256 
257 	vg = nbp_vlan_group(p);
258 	/* Search all chains since old address/hash is unknown */
259 	for (i = 0; i < BR_HASH_SIZE; i++) {
260 		struct hlist_node *h;
261 		hlist_for_each(h, &br->hash[i]) {
262 			struct net_bridge_fdb_entry *f;
263 
264 			f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
265 			if (f->dst == p && f->is_local && !f->added_by_user) {
266 				/* delete old one */
267 				fdb_delete_local(br, p, f);
268 
269 				/* if this port has no vlan information
270 				 * configured, we can safely be done at
271 				 * this point.
272 				 */
273 				if (!vg || !vg->num_vlans)
274 					goto insert;
275 			}
276 		}
277 	}
278 
279 insert:
280 	/* insert new address,  may fail if invalid address or dup. */
281 	fdb_insert(br, p, newaddr, 0);
282 
283 	if (!vg || !vg->num_vlans)
284 		goto done;
285 
286 	/* Now add entries for every VLAN configured on the port.
287 	 * This function runs under RTNL so the bitmap will not change
288 	 * from under us.
289 	 */
290 	list_for_each_entry(v, &vg->vlan_list, vlist)
291 		fdb_insert(br, p, newaddr, v->vid);
292 
293 done:
294 	spin_unlock_bh(&br->hash_lock);
295 }
296 
297 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
298 {
299 	struct net_bridge_vlan_group *vg;
300 	struct net_bridge_fdb_entry *f;
301 	struct net_bridge_vlan *v;
302 
303 	spin_lock_bh(&br->hash_lock);
304 
305 	/* If old entry was unassociated with any port, then delete it. */
306 	f = br_fdb_find(br, br->dev->dev_addr, 0);
307 	if (f && f->is_local && !f->dst && !f->added_by_user)
308 		fdb_delete_local(br, NULL, f);
309 
310 	fdb_insert(br, NULL, newaddr, 0);
311 	vg = br_vlan_group(br);
312 	if (!vg || !vg->num_vlans)
313 		goto out;
314 	/* Now remove and add entries for every VLAN configured on the
315 	 * bridge.  This function runs under RTNL so the bitmap will not
316 	 * change from under us.
317 	 */
318 	list_for_each_entry(v, &vg->vlan_list, vlist) {
319 		if (!br_vlan_should_use(v))
320 			continue;
321 		f = br_fdb_find(br, br->dev->dev_addr, v->vid);
322 		if (f && f->is_local && !f->dst && !f->added_by_user)
323 			fdb_delete_local(br, NULL, f);
324 		fdb_insert(br, NULL, newaddr, v->vid);
325 	}
326 out:
327 	spin_unlock_bh(&br->hash_lock);
328 }
329 
330 void br_fdb_cleanup(struct work_struct *work)
331 {
332 	struct net_bridge *br = container_of(work, struct net_bridge,
333 					     gc_work.work);
334 	unsigned long delay = hold_time(br);
335 	unsigned long work_delay = delay;
336 	unsigned long now = jiffies;
337 	int i;
338 
339 	for (i = 0; i < BR_HASH_SIZE; i++) {
340 		struct net_bridge_fdb_entry *f;
341 		struct hlist_node *n;
342 
343 		if (!br->hash[i].first)
344 			continue;
345 
346 		spin_lock_bh(&br->hash_lock);
347 		hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
348 			unsigned long this_timer;
349 
350 			if (f->is_static)
351 				continue;
352 			if (f->added_by_external_learn)
353 				continue;
354 			this_timer = f->updated + delay;
355 			if (time_after(this_timer, now))
356 				work_delay = min(work_delay, this_timer - now);
357 			else
358 				fdb_delete(br, f);
359 		}
360 		spin_unlock_bh(&br->hash_lock);
361 		cond_resched();
362 	}
363 
364 	/* Cleanup minimum 10 milliseconds apart */
365 	work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
366 	mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
367 }
368 
369 /* Completely flush all dynamic entries in forwarding database.*/
370 void br_fdb_flush(struct net_bridge *br)
371 {
372 	int i;
373 
374 	spin_lock_bh(&br->hash_lock);
375 	for (i = 0; i < BR_HASH_SIZE; i++) {
376 		struct net_bridge_fdb_entry *f;
377 		struct hlist_node *n;
378 		hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
379 			if (!f->is_static)
380 				fdb_delete(br, f);
381 		}
382 	}
383 	spin_unlock_bh(&br->hash_lock);
384 }
385 
386 /* Flush all entries referring to a specific port.
387  * if do_all is set also flush static entries
388  * if vid is set delete all entries that match the vlan_id
389  */
390 void br_fdb_delete_by_port(struct net_bridge *br,
391 			   const struct net_bridge_port *p,
392 			   u16 vid,
393 			   int do_all)
394 {
395 	int i;
396 
397 	spin_lock_bh(&br->hash_lock);
398 	for (i = 0; i < BR_HASH_SIZE; i++) {
399 		struct hlist_node *h, *g;
400 
401 		hlist_for_each_safe(h, g, &br->hash[i]) {
402 			struct net_bridge_fdb_entry *f
403 				= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
404 			if (f->dst != p)
405 				continue;
406 
407 			if (!do_all)
408 				if (f->is_static || (vid && f->vlan_id != vid))
409 					continue;
410 
411 			if (f->is_local)
412 				fdb_delete_local(br, p, f);
413 			else
414 				fdb_delete(br, f);
415 		}
416 	}
417 	spin_unlock_bh(&br->hash_lock);
418 }
419 
420 #if IS_ENABLED(CONFIG_ATM_LANE)
421 /* Interface used by ATM LANE hook to test
422  * if an addr is on some other bridge port */
423 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
424 {
425 	struct net_bridge_fdb_entry *fdb;
426 	struct net_bridge_port *port;
427 	int ret;
428 
429 	rcu_read_lock();
430 	port = br_port_get_rcu(dev);
431 	if (!port)
432 		ret = 0;
433 	else {
434 		fdb = br_fdb_find_rcu(port->br, addr, 0);
435 		ret = fdb && fdb->dst && fdb->dst->dev != dev &&
436 			fdb->dst->state == BR_STATE_FORWARDING;
437 	}
438 	rcu_read_unlock();
439 
440 	return ret;
441 }
442 #endif /* CONFIG_ATM_LANE */
443 
444 /*
445  * Fill buffer with forwarding table records in
446  * the API format.
447  */
448 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
449 		   unsigned long maxnum, unsigned long skip)
450 {
451 	struct __fdb_entry *fe = buf;
452 	int i, num = 0;
453 	struct net_bridge_fdb_entry *f;
454 
455 	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
456 
457 	rcu_read_lock();
458 	for (i = 0; i < BR_HASH_SIZE; i++) {
459 		hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
460 			if (num >= maxnum)
461 				goto out;
462 
463 			if (has_expired(br, f))
464 				continue;
465 
466 			/* ignore pseudo entry for local MAC address */
467 			if (!f->dst)
468 				continue;
469 
470 			if (skip) {
471 				--skip;
472 				continue;
473 			}
474 
475 			/* convert from internal format to API */
476 			memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
477 
478 			/* due to ABI compat need to split into hi/lo */
479 			fe->port_no = f->dst->port_no;
480 			fe->port_hi = f->dst->port_no >> 8;
481 
482 			fe->is_local = f->is_local;
483 			if (!f->is_static)
484 				fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
485 			++fe;
486 			++num;
487 		}
488 	}
489 
490  out:
491 	rcu_read_unlock();
492 
493 	return num;
494 }
495 
496 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
497 					       struct net_bridge_port *source,
498 					       const unsigned char *addr,
499 					       __u16 vid,
500 					       unsigned char is_local,
501 					       unsigned char is_static)
502 {
503 	struct net_bridge_fdb_entry *fdb;
504 
505 	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
506 	if (fdb) {
507 		memcpy(fdb->addr.addr, addr, ETH_ALEN);
508 		fdb->dst = source;
509 		fdb->vlan_id = vid;
510 		fdb->is_local = is_local;
511 		fdb->is_static = is_static;
512 		fdb->added_by_user = 0;
513 		fdb->added_by_external_learn = 0;
514 		fdb->updated = fdb->used = jiffies;
515 		hlist_add_head_rcu(&fdb->hlist, head);
516 	}
517 	return fdb;
518 }
519 
520 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
521 		  const unsigned char *addr, u16 vid)
522 {
523 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
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);
539 	}
540 
541 	fdb = fdb_create(head, 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);
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 hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
566 	struct net_bridge_fdb_entry *fdb;
567 	bool fdb_modified = false;
568 
569 	/* some users want to always flood. */
570 	if (hold_time(br) == 0)
571 		return;
572 
573 	/* ignore packets unless we are using this port */
574 	if (!(source->state == BR_STATE_LEARNING ||
575 	      source->state == BR_STATE_FORWARDING))
576 		return;
577 
578 	fdb = fdb_find_rcu(head, addr, vid);
579 	if (likely(fdb)) {
580 		/* attempt to update an entry for a local interface */
581 		if (unlikely(fdb->is_local)) {
582 			if (net_ratelimit())
583 				br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
584 					source->dev->name, addr, vid);
585 		} else {
586 			unsigned long now = jiffies;
587 
588 			/* fastpath: update of existing entry */
589 			if (unlikely(source != fdb->dst)) {
590 				fdb->dst = source;
591 				fdb_modified = true;
592 			}
593 			if (now != fdb->updated)
594 				fdb->updated = now;
595 			if (unlikely(added_by_user))
596 				fdb->added_by_user = 1;
597 			if (unlikely(fdb_modified))
598 				fdb_notify(br, fdb, RTM_NEWNEIGH);
599 		}
600 	} else {
601 		spin_lock(&br->hash_lock);
602 		if (likely(!fdb_find_rcu(head, addr, vid))) {
603 			fdb = fdb_create(head, source, addr, vid, 0, 0);
604 			if (fdb) {
605 				if (unlikely(added_by_user))
606 					fdb->added_by_user = 1;
607 				fdb_notify(br, fdb, RTM_NEWNEIGH);
608 			}
609 		}
610 		/* else  we lose race and someone else inserts
611 		 * it first, don't bother updating
612 		 */
613 		spin_unlock(&br->hash_lock);
614 	}
615 }
616 
617 static int fdb_to_nud(const struct net_bridge *br,
618 		      const struct net_bridge_fdb_entry *fdb)
619 {
620 	if (fdb->is_local)
621 		return NUD_PERMANENT;
622 	else if (fdb->is_static)
623 		return NUD_NOARP;
624 	else if (has_expired(br, fdb))
625 		return NUD_STALE;
626 	else
627 		return NUD_REACHABLE;
628 }
629 
630 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
631 			 const struct net_bridge_fdb_entry *fdb,
632 			 u32 portid, u32 seq, int type, unsigned int flags)
633 {
634 	unsigned long now = jiffies;
635 	struct nda_cacheinfo ci;
636 	struct nlmsghdr *nlh;
637 	struct ndmsg *ndm;
638 
639 	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
640 	if (nlh == NULL)
641 		return -EMSGSIZE;
642 
643 	ndm = nlmsg_data(nlh);
644 	ndm->ndm_family	 = AF_BRIDGE;
645 	ndm->ndm_pad1    = 0;
646 	ndm->ndm_pad2    = 0;
647 	ndm->ndm_flags	 = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0;
648 	ndm->ndm_type	 = 0;
649 	ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
650 	ndm->ndm_state   = fdb_to_nud(br, fdb);
651 
652 	if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
653 		goto nla_put_failure;
654 	if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
655 		goto nla_put_failure;
656 	ci.ndm_used	 = jiffies_to_clock_t(now - fdb->used);
657 	ci.ndm_confirmed = 0;
658 	ci.ndm_updated	 = jiffies_to_clock_t(now - fdb->updated);
659 	ci.ndm_refcnt	 = 0;
660 	if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
661 		goto nla_put_failure;
662 
663 	if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
664 		goto nla_put_failure;
665 
666 	nlmsg_end(skb, nlh);
667 	return 0;
668 
669 nla_put_failure:
670 	nlmsg_cancel(skb, nlh);
671 	return -EMSGSIZE;
672 }
673 
674 static inline size_t fdb_nlmsg_size(void)
675 {
676 	return NLMSG_ALIGN(sizeof(struct ndmsg))
677 		+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
678 		+ nla_total_size(sizeof(u32)) /* NDA_MASTER */
679 		+ nla_total_size(sizeof(u16)) /* NDA_VLAN */
680 		+ nla_total_size(sizeof(struct nda_cacheinfo));
681 }
682 
683 static void fdb_notify(struct net_bridge *br,
684 		       const struct net_bridge_fdb_entry *fdb, int type)
685 {
686 	struct net *net = dev_net(br->dev);
687 	struct sk_buff *skb;
688 	int err = -ENOBUFS;
689 
690 	skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
691 	if (skb == NULL)
692 		goto errout;
693 
694 	err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
695 	if (err < 0) {
696 		/* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
697 		WARN_ON(err == -EMSGSIZE);
698 		kfree_skb(skb);
699 		goto errout;
700 	}
701 	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
702 	return;
703 errout:
704 	rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
705 }
706 
707 /* Dump information about entries, in response to GETNEIGH */
708 int br_fdb_dump(struct sk_buff *skb,
709 		struct netlink_callback *cb,
710 		struct net_device *dev,
711 		struct net_device *filter_dev,
712 		int *idx)
713 {
714 	struct net_bridge *br = netdev_priv(dev);
715 	int err = 0;
716 	int i;
717 
718 	if (!(dev->priv_flags & IFF_EBRIDGE))
719 		goto out;
720 
721 	if (!filter_dev) {
722 		err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
723 		if (err < 0)
724 			goto out;
725 	}
726 
727 	for (i = 0; i < BR_HASH_SIZE; i++) {
728 		struct net_bridge_fdb_entry *f;
729 
730 		hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
731 
732 			if (*idx < cb->args[2])
733 				goto skip;
734 
735 			if (filter_dev &&
736 			    (!f->dst || f->dst->dev != filter_dev)) {
737 				if (filter_dev != dev)
738 					goto skip;
739 				/* !f->dst is a special case for bridge
740 				 * It means the MAC belongs to the bridge
741 				 * Therefore need a little more filtering
742 				 * we only want to dump the !f->dst case
743 				 */
744 				if (f->dst)
745 					goto skip;
746 			}
747 			if (!filter_dev && f->dst)
748 				goto skip;
749 
750 			err = fdb_fill_info(skb, br, f,
751 					    NETLINK_CB(cb->skb).portid,
752 					    cb->nlh->nlmsg_seq,
753 					    RTM_NEWNEIGH,
754 					    NLM_F_MULTI);
755 			if (err < 0)
756 				goto out;
757 skip:
758 			*idx += 1;
759 		}
760 	}
761 
762 out:
763 	return err;
764 }
765 
766 /* Update (create or replace) forwarding database entry */
767 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
768 			 const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
769 {
770 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
771 	struct net_bridge_fdb_entry *fdb;
772 	bool modified = false;
773 
774 	/* If the port cannot learn allow only local and static entries */
775 	if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
776 	    !(source->state == BR_STATE_LEARNING ||
777 	      source->state == BR_STATE_FORWARDING))
778 		return -EPERM;
779 
780 	if (!source && !(state & NUD_PERMANENT)) {
781 		pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
782 			br->dev->name);
783 		return -EINVAL;
784 	}
785 
786 	fdb = br_fdb_find(br, addr, vid);
787 	if (fdb == NULL) {
788 		if (!(flags & NLM_F_CREATE))
789 			return -ENOENT;
790 
791 		fdb = fdb_create(head, source, addr, vid, 0, 0);
792 		if (!fdb)
793 			return -ENOMEM;
794 
795 		modified = true;
796 	} else {
797 		if (flags & NLM_F_EXCL)
798 			return -EEXIST;
799 
800 		if (fdb->dst != source) {
801 			fdb->dst = source;
802 			modified = true;
803 		}
804 	}
805 
806 	if (fdb_to_nud(br, fdb) != state) {
807 		if (state & NUD_PERMANENT) {
808 			fdb->is_local = 1;
809 			if (!fdb->is_static) {
810 				fdb->is_static = 1;
811 				fdb_add_hw_addr(br, addr);
812 			}
813 		} else if (state & NUD_NOARP) {
814 			fdb->is_local = 0;
815 			if (!fdb->is_static) {
816 				fdb->is_static = 1;
817 				fdb_add_hw_addr(br, addr);
818 			}
819 		} else {
820 			fdb->is_local = 0;
821 			if (fdb->is_static) {
822 				fdb->is_static = 0;
823 				fdb_del_hw_addr(br, addr);
824 			}
825 		}
826 
827 		modified = true;
828 	}
829 	fdb->added_by_user = 1;
830 
831 	fdb->used = jiffies;
832 	if (modified) {
833 		fdb->updated = jiffies;
834 		fdb_notify(br, fdb, RTM_NEWNEIGH);
835 	}
836 
837 	return 0;
838 }
839 
840 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
841 			struct net_bridge_port *p, const unsigned char *addr,
842 			u16 nlh_flags, u16 vid)
843 {
844 	int err = 0;
845 
846 	if (ndm->ndm_flags & NTF_USE) {
847 		if (!p) {
848 			pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
849 				br->dev->name);
850 			return -EINVAL;
851 		}
852 		local_bh_disable();
853 		rcu_read_lock();
854 		br_fdb_update(br, p, addr, vid, true);
855 		rcu_read_unlock();
856 		local_bh_enable();
857 	} else {
858 		spin_lock_bh(&br->hash_lock);
859 		err = fdb_add_entry(br, p, addr, ndm->ndm_state,
860 				    nlh_flags, vid);
861 		spin_unlock_bh(&br->hash_lock);
862 	}
863 
864 	return err;
865 }
866 
867 /* Add new permanent fdb entry with RTM_NEWNEIGH */
868 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
869 	       struct net_device *dev,
870 	       const unsigned char *addr, u16 vid, u16 nlh_flags)
871 {
872 	struct net_bridge_vlan_group *vg;
873 	struct net_bridge_port *p = NULL;
874 	struct net_bridge_vlan *v;
875 	struct net_bridge *br = NULL;
876 	int err = 0;
877 
878 	if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
879 		pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
880 		return -EINVAL;
881 	}
882 
883 	if (is_zero_ether_addr(addr)) {
884 		pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
885 		return -EINVAL;
886 	}
887 
888 	if (dev->priv_flags & IFF_EBRIDGE) {
889 		br = netdev_priv(dev);
890 		vg = br_vlan_group(br);
891 	} else {
892 		p = br_port_get_rtnl(dev);
893 		if (!p) {
894 			pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
895 				dev->name);
896 			return -EINVAL;
897 		}
898 		br = p->br;
899 		vg = nbp_vlan_group(p);
900 	}
901 
902 	if (vid) {
903 		v = br_vlan_find(vg, vid);
904 		if (!v || !br_vlan_should_use(v)) {
905 			pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
906 			return -EINVAL;
907 		}
908 
909 		/* VID was specified, so use it. */
910 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
911 	} else {
912 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
913 		if (err || !vg || !vg->num_vlans)
914 			goto out;
915 
916 		/* We have vlans configured on this port and user didn't
917 		 * specify a VLAN.  To be nice, add/update entry for every
918 		 * vlan on this port.
919 		 */
920 		list_for_each_entry(v, &vg->vlan_list, vlist) {
921 			if (!br_vlan_should_use(v))
922 				continue;
923 			err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
924 			if (err)
925 				goto out;
926 		}
927 	}
928 
929 out:
930 	return err;
931 }
932 
933 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
934 				       const struct net_bridge_port *p,
935 				       const u8 *addr, u16 vlan)
936 {
937 	struct net_bridge_fdb_entry *fdb;
938 
939 	fdb = br_fdb_find(br, addr, vlan);
940 	if (!fdb || fdb->dst != p)
941 		return -ENOENT;
942 
943 	fdb_delete(br, fdb);
944 
945 	return 0;
946 }
947 
948 static int __br_fdb_delete(struct net_bridge *br,
949 			   const struct net_bridge_port *p,
950 			   const unsigned char *addr, u16 vid)
951 {
952 	int err;
953 
954 	spin_lock_bh(&br->hash_lock);
955 	err = fdb_delete_by_addr_and_port(br, p, addr, vid);
956 	spin_unlock_bh(&br->hash_lock);
957 
958 	return err;
959 }
960 
961 /* Remove neighbor entry with RTM_DELNEIGH */
962 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
963 		  struct net_device *dev,
964 		  const unsigned char *addr, u16 vid)
965 {
966 	struct net_bridge_vlan_group *vg;
967 	struct net_bridge_port *p = NULL;
968 	struct net_bridge_vlan *v;
969 	struct net_bridge *br;
970 	int err;
971 
972 	if (dev->priv_flags & IFF_EBRIDGE) {
973 		br = netdev_priv(dev);
974 		vg = br_vlan_group(br);
975 	} else {
976 		p = br_port_get_rtnl(dev);
977 		if (!p) {
978 			pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
979 				dev->name);
980 			return -EINVAL;
981 		}
982 		vg = nbp_vlan_group(p);
983 		br = p->br;
984 	}
985 
986 	if (vid) {
987 		v = br_vlan_find(vg, vid);
988 		if (!v) {
989 			pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
990 			return -EINVAL;
991 		}
992 
993 		err = __br_fdb_delete(br, p, addr, vid);
994 	} else {
995 		err = -ENOENT;
996 		err &= __br_fdb_delete(br, p, addr, 0);
997 		if (!vg || !vg->num_vlans)
998 			return err;
999 
1000 		list_for_each_entry(v, &vg->vlan_list, vlist) {
1001 			if (!br_vlan_should_use(v))
1002 				continue;
1003 			err &= __br_fdb_delete(br, p, addr, v->vid);
1004 		}
1005 	}
1006 
1007 	return err;
1008 }
1009 
1010 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1011 {
1012 	struct net_bridge_fdb_entry *fdb, *tmp;
1013 	int i;
1014 	int err;
1015 
1016 	ASSERT_RTNL();
1017 
1018 	for (i = 0; i < BR_HASH_SIZE; i++) {
1019 		hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1020 			/* We only care for static entries */
1021 			if (!fdb->is_static)
1022 				continue;
1023 
1024 			err = dev_uc_add(p->dev, fdb->addr.addr);
1025 			if (err)
1026 				goto rollback;
1027 		}
1028 	}
1029 	return 0;
1030 
1031 rollback:
1032 	for (i = 0; i < BR_HASH_SIZE; i++) {
1033 		hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1034 			/* If we reached the fdb that failed, we can stop */
1035 			if (tmp == fdb)
1036 				break;
1037 
1038 			/* We only care for static entries */
1039 			if (!tmp->is_static)
1040 				continue;
1041 
1042 			dev_uc_del(p->dev, tmp->addr.addr);
1043 		}
1044 	}
1045 	return err;
1046 }
1047 
1048 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1049 {
1050 	struct net_bridge_fdb_entry *fdb;
1051 	int i;
1052 
1053 	ASSERT_RTNL();
1054 
1055 	for (i = 0; i < BR_HASH_SIZE; i++) {
1056 		hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1057 			/* We only care for static entries */
1058 			if (!fdb->is_static)
1059 				continue;
1060 
1061 			dev_uc_del(p->dev, fdb->addr.addr);
1062 		}
1063 	}
1064 }
1065 
1066 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1067 			      const unsigned char *addr, u16 vid)
1068 {
1069 	struct hlist_head *head;
1070 	struct net_bridge_fdb_entry *fdb;
1071 	int err = 0;
1072 
1073 	ASSERT_RTNL();
1074 	spin_lock_bh(&br->hash_lock);
1075 
1076 	head = &br->hash[br_mac_hash(addr, vid)];
1077 	fdb = br_fdb_find(br, addr, vid);
1078 	if (!fdb) {
1079 		fdb = fdb_create(head, p, addr, vid, 0, 0);
1080 		if (!fdb) {
1081 			err = -ENOMEM;
1082 			goto err_unlock;
1083 		}
1084 		fdb->added_by_external_learn = 1;
1085 		fdb_notify(br, fdb, RTM_NEWNEIGH);
1086 	} else if (fdb->added_by_external_learn) {
1087 		/* Refresh entry */
1088 		fdb->updated = fdb->used = jiffies;
1089 	} else if (!fdb->added_by_user) {
1090 		/* Take over SW learned entry */
1091 		fdb->added_by_external_learn = 1;
1092 		fdb->updated = jiffies;
1093 		fdb_notify(br, fdb, RTM_NEWNEIGH);
1094 	}
1095 
1096 err_unlock:
1097 	spin_unlock_bh(&br->hash_lock);
1098 
1099 	return err;
1100 }
1101 
1102 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1103 			      const unsigned char *addr, u16 vid)
1104 {
1105 	struct net_bridge_fdb_entry *fdb;
1106 	int err = 0;
1107 
1108 	ASSERT_RTNL();
1109 	spin_lock_bh(&br->hash_lock);
1110 
1111 	fdb = br_fdb_find(br, addr, vid);
1112 	if (fdb && fdb->added_by_external_learn)
1113 		fdb_delete(br, fdb);
1114 	else
1115 		err = -ENOENT;
1116 
1117 	spin_unlock_bh(&br->hash_lock);
1118 
1119 	return err;
1120 }
1121