• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 
br_fdb_init(void)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 
br_fdb_fini(void)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  */
hold_time(const struct net_bridge * br)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 
has_expired(const struct net_bridge * br,const struct net_bridge_fdb_entry * fdb)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 
br_mac_hash(const unsigned char * mac,__u16 vid)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 
fdb_rcu_free(struct rcu_head * head)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  */
fdb_add_hw_addr(struct net_bridge * br,const unsigned char * addr)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  */
fdb_del_hw_addr(struct net_bridge * br,const unsigned char * addr)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 
fdb_del_external_learn(struct net_bridge_fdb_entry * f)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 
fdb_delete(struct net_bridge * br,struct net_bridge_fdb_entry * f)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. */
fdb_delete_local(struct net_bridge * br,const struct net_bridge_port * p,struct net_bridge_fdb_entry * f)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 
br_fdb_find_delete_local(struct net_bridge * br,const struct net_bridge_port * p,const unsigned char * addr,u16 vid)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 
br_fdb_changeaddr(struct net_bridge_port * p,const unsigned char * newaddr)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 
br_fdb_change_mac_address(struct net_bridge * br,const u8 * newaddr)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 
br_fdb_cleanup(unsigned long _data)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.*/
br_fdb_flush(struct net_bridge * br)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  */
br_fdb_delete_by_port(struct net_bridge * br,const struct net_bridge_port * p,u16 vid,int do_all)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 */
__br_fdb_get(struct net_bridge * br,const unsigned char * addr,__u16 vid)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 */
br_fdb_test_addr(struct net_device * dev,unsigned char * addr)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  */
br_fdb_fillbuf(struct net_bridge * br,void * buf,unsigned long maxnum,unsigned long skip)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 
fdb_find(struct hlist_head * head,const unsigned char * addr,__u16 vid)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 
fdb_find_rcu(struct hlist_head * head,const unsigned char * addr,__u16 vid)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 
fdb_create(struct hlist_head * head,struct net_bridge_port * source,const unsigned char * addr,__u16 vid,unsigned char is_local,unsigned char is_static)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 
fdb_insert(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid)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 "
539 		       "as a received packet\n",
540 		       source ? source->dev->name : br->dev->name);
541 		fdb_delete(br, fdb);
542 	}
543 
544 	fdb = fdb_create(head, source, addr, vid, 1, 1);
545 	if (!fdb)
546 		return -ENOMEM;
547 
548 	fdb_add_hw_addr(br, addr);
549 	fdb_notify(br, fdb, RTM_NEWNEIGH);
550 	return 0;
551 }
552 
553 /* Add entry for local address of interface */
br_fdb_insert(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid)554 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
555 		  const unsigned char *addr, u16 vid)
556 {
557 	int ret;
558 
559 	spin_lock_bh(&br->hash_lock);
560 	ret = fdb_insert(br, source, addr, vid);
561 	spin_unlock_bh(&br->hash_lock);
562 	return ret;
563 }
564 
br_fdb_update(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid,bool added_by_user)565 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
566 		   const unsigned char *addr, u16 vid, bool added_by_user)
567 {
568 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
569 	struct net_bridge_fdb_entry *fdb;
570 	bool fdb_modified = false;
571 
572 	/* some users want to always flood. */
573 	if (hold_time(br) == 0)
574 		return;
575 
576 	/* ignore packets unless we are using this port */
577 	if (!(source->state == BR_STATE_LEARNING ||
578 	      source->state == BR_STATE_FORWARDING))
579 		return;
580 
581 	fdb = fdb_find_rcu(head, addr, vid);
582 	if (likely(fdb)) {
583 		/* attempt to update an entry for a local interface */
584 		if (unlikely(fdb->is_local)) {
585 			if (net_ratelimit())
586 				br_warn(br, "received packet on %s with "
587 					"own address as source address\n",
588 					source->dev->name);
589 		} else {
590 			/* fastpath: update of existing entry */
591 			if (unlikely(source != fdb->dst)) {
592 				fdb->dst = source;
593 				fdb_modified = true;
594 			}
595 			fdb->updated = jiffies;
596 			if (unlikely(added_by_user))
597 				fdb->added_by_user = 1;
598 			if (unlikely(fdb_modified))
599 				fdb_notify(br, fdb, RTM_NEWNEIGH);
600 		}
601 	} else {
602 		spin_lock(&br->hash_lock);
603 		if (likely(!fdb_find(head, addr, vid))) {
604 			fdb = fdb_create(head, source, addr, vid, 0, 0);
605 			if (fdb) {
606 				if (unlikely(added_by_user))
607 					fdb->added_by_user = 1;
608 				fdb_notify(br, fdb, RTM_NEWNEIGH);
609 			}
610 		}
611 		/* else  we lose race and someone else inserts
612 		 * it first, don't bother updating
613 		 */
614 		spin_unlock(&br->hash_lock);
615 	}
616 }
617 
fdb_to_nud(const struct net_bridge * br,const struct net_bridge_fdb_entry * fdb)618 static int fdb_to_nud(const struct net_bridge *br,
619 		      const struct net_bridge_fdb_entry *fdb)
620 {
621 	if (fdb->is_local)
622 		return NUD_PERMANENT;
623 	else if (fdb->is_static)
624 		return NUD_NOARP;
625 	else if (has_expired(br, fdb))
626 		return NUD_STALE;
627 	else
628 		return NUD_REACHABLE;
629 }
630 
fdb_fill_info(struct sk_buff * skb,const struct net_bridge * br,const struct net_bridge_fdb_entry * fdb,u32 portid,u32 seq,int type,unsigned int flags)631 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
632 			 const struct net_bridge_fdb_entry *fdb,
633 			 u32 portid, u32 seq, int type, unsigned int flags)
634 {
635 	unsigned long now = jiffies;
636 	struct nda_cacheinfo ci;
637 	struct nlmsghdr *nlh;
638 	struct ndmsg *ndm;
639 
640 	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
641 	if (nlh == NULL)
642 		return -EMSGSIZE;
643 
644 	ndm = nlmsg_data(nlh);
645 	ndm->ndm_family	 = AF_BRIDGE;
646 	ndm->ndm_pad1    = 0;
647 	ndm->ndm_pad2    = 0;
648 	ndm->ndm_flags	 = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0;
649 	ndm->ndm_type	 = 0;
650 	ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
651 	ndm->ndm_state   = fdb_to_nud(br, fdb);
652 
653 	if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
654 		goto nla_put_failure;
655 	if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
656 		goto nla_put_failure;
657 	ci.ndm_used	 = jiffies_to_clock_t(now - fdb->used);
658 	ci.ndm_confirmed = 0;
659 	ci.ndm_updated	 = jiffies_to_clock_t(now - fdb->updated);
660 	ci.ndm_refcnt	 = 0;
661 	if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
662 		goto nla_put_failure;
663 
664 	if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
665 		goto nla_put_failure;
666 
667 	nlmsg_end(skb, nlh);
668 	return 0;
669 
670 nla_put_failure:
671 	nlmsg_cancel(skb, nlh);
672 	return -EMSGSIZE;
673 }
674 
fdb_nlmsg_size(void)675 static inline size_t fdb_nlmsg_size(void)
676 {
677 	return NLMSG_ALIGN(sizeof(struct ndmsg))
678 		+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
679 		+ nla_total_size(sizeof(u32)) /* NDA_MASTER */
680 		+ nla_total_size(sizeof(u16)) /* NDA_VLAN */
681 		+ nla_total_size(sizeof(struct nda_cacheinfo));
682 }
683 
fdb_notify(struct net_bridge * br,const struct net_bridge_fdb_entry * fdb,int type)684 static void fdb_notify(struct net_bridge *br,
685 		       const struct net_bridge_fdb_entry *fdb, int type)
686 {
687 	struct net *net = dev_net(br->dev);
688 	struct sk_buff *skb;
689 	int err = -ENOBUFS;
690 
691 	skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
692 	if (skb == NULL)
693 		goto errout;
694 
695 	err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
696 	if (err < 0) {
697 		/* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
698 		WARN_ON(err == -EMSGSIZE);
699 		kfree_skb(skb);
700 		goto errout;
701 	}
702 	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
703 	return;
704 errout:
705 	rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
706 }
707 
708 /* Dump information about entries, in response to GETNEIGH */
br_fdb_dump(struct sk_buff * skb,struct netlink_callback * cb,struct net_device * dev,struct net_device * filter_dev,int * idx)709 int br_fdb_dump(struct sk_buff *skb,
710 		struct netlink_callback *cb,
711 		struct net_device *dev,
712 		struct net_device *filter_dev,
713 		int *idx)
714 {
715 	struct net_bridge *br = netdev_priv(dev);
716 	int err = 0;
717 	int i;
718 
719 	if (!(dev->priv_flags & IFF_EBRIDGE))
720 		goto out;
721 
722 	if (!filter_dev) {
723 		err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
724 		if (err < 0)
725 			goto out;
726 	}
727 
728 	for (i = 0; i < BR_HASH_SIZE; i++) {
729 		struct net_bridge_fdb_entry *f;
730 
731 		hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
732 
733 			if (*idx < cb->args[2])
734 				goto skip;
735 
736 			if (filter_dev &&
737 			    (!f->dst || f->dst->dev != filter_dev)) {
738 				if (filter_dev != dev)
739 					goto skip;
740 				/* !f->dst is a special case for bridge
741 				 * It means the MAC belongs to the bridge
742 				 * Therefore need a little more filtering
743 				 * we only want to dump the !f->dst case
744 				 */
745 				if (f->dst)
746 					goto skip;
747 			}
748 			if (!filter_dev && f->dst)
749 				goto skip;
750 
751 			err = fdb_fill_info(skb, br, f,
752 					    NETLINK_CB(cb->skb).portid,
753 					    cb->nlh->nlmsg_seq,
754 					    RTM_NEWNEIGH,
755 					    NLM_F_MULTI);
756 			if (err < 0)
757 				goto out;
758 skip:
759 			*idx += 1;
760 		}
761 	}
762 
763 out:
764 	return err;
765 }
766 
767 /* Update (create or replace) forwarding database entry */
fdb_add_entry(struct net_bridge * br,struct net_bridge_port * source,const __u8 * addr,__u16 state,__u16 flags,__u16 vid)768 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
769 			 const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
770 {
771 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
772 	struct net_bridge_fdb_entry *fdb;
773 	bool modified = false;
774 
775 	/* If the port cannot learn allow only local and static entries */
776 	if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
777 	    !(source->state == BR_STATE_LEARNING ||
778 	      source->state == BR_STATE_FORWARDING))
779 		return -EPERM;
780 
781 	if (!source && !(state & NUD_PERMANENT)) {
782 		pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
783 			br->dev->name);
784 		return -EINVAL;
785 	}
786 
787 	fdb = fdb_find(head, addr, vid);
788 	if (fdb == NULL) {
789 		if (!(flags & NLM_F_CREATE))
790 			return -ENOENT;
791 
792 		fdb = fdb_create(head, source, addr, vid, 0, 0);
793 		if (!fdb)
794 			return -ENOMEM;
795 
796 		modified = true;
797 	} else {
798 		if (flags & NLM_F_EXCL)
799 			return -EEXIST;
800 
801 		if (fdb->dst != source) {
802 			fdb->dst = source;
803 			modified = true;
804 		}
805 	}
806 
807 	if (fdb_to_nud(br, fdb) != state) {
808 		if (state & NUD_PERMANENT) {
809 			fdb->is_local = 1;
810 			if (!fdb->is_static) {
811 				fdb->is_static = 1;
812 				fdb_add_hw_addr(br, addr);
813 			}
814 		} else if (state & NUD_NOARP) {
815 			fdb->is_local = 0;
816 			if (!fdb->is_static) {
817 				fdb->is_static = 1;
818 				fdb_add_hw_addr(br, addr);
819 			}
820 		} else {
821 			fdb->is_local = 0;
822 			if (fdb->is_static) {
823 				fdb->is_static = 0;
824 				fdb_del_hw_addr(br, addr);
825 			}
826 		}
827 
828 		modified = true;
829 	}
830 	fdb->added_by_user = 1;
831 
832 	fdb->used = jiffies;
833 	if (modified) {
834 		fdb->updated = jiffies;
835 		fdb_notify(br, fdb, RTM_NEWNEIGH);
836 	}
837 
838 	return 0;
839 }
840 
__br_fdb_add(struct ndmsg * ndm,struct net_bridge * br,struct net_bridge_port * p,const unsigned char * addr,u16 nlh_flags,u16 vid)841 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
842 			struct net_bridge_port *p, const unsigned char *addr,
843 			u16 nlh_flags, u16 vid)
844 {
845 	int err = 0;
846 
847 	if (ndm->ndm_flags & NTF_USE) {
848 		if (!p) {
849 			pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
850 				br->dev->name);
851 			return -EINVAL;
852 		}
853 		local_bh_disable();
854 		rcu_read_lock();
855 		br_fdb_update(br, p, addr, vid, true);
856 		rcu_read_unlock();
857 		local_bh_enable();
858 	} else {
859 		spin_lock_bh(&br->hash_lock);
860 		err = fdb_add_entry(br, p, addr, ndm->ndm_state,
861 				    nlh_flags, vid);
862 		spin_unlock_bh(&br->hash_lock);
863 	}
864 
865 	return err;
866 }
867 
868 /* Add new permanent fdb entry with RTM_NEWNEIGH */
br_fdb_add(struct ndmsg * ndm,struct nlattr * tb[],struct net_device * dev,const unsigned char * addr,u16 vid,u16 nlh_flags)869 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
870 	       struct net_device *dev,
871 	       const unsigned char *addr, u16 vid, u16 nlh_flags)
872 {
873 	struct net_bridge_vlan_group *vg;
874 	struct net_bridge_port *p = NULL;
875 	struct net_bridge_vlan *v;
876 	struct net_bridge *br = NULL;
877 	int err = 0;
878 
879 	if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
880 		pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
881 		return -EINVAL;
882 	}
883 
884 	if (is_zero_ether_addr(addr)) {
885 		pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
886 		return -EINVAL;
887 	}
888 
889 	if (dev->priv_flags & IFF_EBRIDGE) {
890 		br = netdev_priv(dev);
891 		vg = br_vlan_group(br);
892 	} else {
893 		p = br_port_get_rtnl(dev);
894 		if (!p) {
895 			pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
896 				dev->name);
897 			return -EINVAL;
898 		}
899 		br = p->br;
900 		vg = nbp_vlan_group(p);
901 	}
902 
903 	if (vid) {
904 		v = br_vlan_find(vg, vid);
905 		if (!v || !br_vlan_should_use(v)) {
906 			pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
907 			return -EINVAL;
908 		}
909 
910 		/* VID was specified, so use it. */
911 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
912 	} else {
913 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
914 		if (err || !vg || !vg->num_vlans)
915 			goto out;
916 
917 		/* We have vlans configured on this port and user didn't
918 		 * specify a VLAN.  To be nice, add/update entry for every
919 		 * vlan on this port.
920 		 */
921 		list_for_each_entry(v, &vg->vlan_list, vlist) {
922 			if (!br_vlan_should_use(v))
923 				continue;
924 			err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
925 			if (err)
926 				goto out;
927 		}
928 	}
929 
930 out:
931 	return err;
932 }
933 
fdb_delete_by_addr(struct net_bridge * br,const u8 * addr,u16 vid)934 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr,
935 			      u16 vid)
936 {
937 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
938 	struct net_bridge_fdb_entry *fdb;
939 
940 	fdb = fdb_find(head, addr, vid);
941 	if (!fdb)
942 		return -ENOENT;
943 
944 	fdb_delete(br, fdb);
945 	return 0;
946 }
947 
__br_fdb_delete_by_addr(struct net_bridge * br,const unsigned char * addr,u16 vid)948 static int __br_fdb_delete_by_addr(struct net_bridge *br,
949 				   const unsigned char *addr, u16 vid)
950 {
951 	int err;
952 
953 	spin_lock_bh(&br->hash_lock);
954 	err = fdb_delete_by_addr(br, addr, vid);
955 	spin_unlock_bh(&br->hash_lock);
956 
957 	return err;
958 }
959 
fdb_delete_by_addr_and_port(struct net_bridge_port * p,const u8 * addr,u16 vlan)960 static int fdb_delete_by_addr_and_port(struct net_bridge_port *p,
961 				       const u8 *addr, u16 vlan)
962 {
963 	struct net_bridge *br = p->br;
964 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
965 	struct net_bridge_fdb_entry *fdb;
966 
967 	fdb = fdb_find(head, addr, vlan);
968 	if (!fdb || fdb->dst != p)
969 		return -ENOENT;
970 
971 	fdb_delete(br, fdb);
972 	return 0;
973 }
974 
__br_fdb_delete(struct net_bridge_port * p,const unsigned char * addr,u16 vid)975 static int __br_fdb_delete(struct net_bridge_port *p,
976 			   const unsigned char *addr, u16 vid)
977 {
978 	int err;
979 
980 	spin_lock_bh(&p->br->hash_lock);
981 	err = fdb_delete_by_addr_and_port(p, addr, vid);
982 	spin_unlock_bh(&p->br->hash_lock);
983 
984 	return err;
985 }
986 
987 /* Remove neighbor entry with RTM_DELNEIGH */
br_fdb_delete(struct ndmsg * ndm,struct nlattr * tb[],struct net_device * dev,const unsigned char * addr,u16 vid)988 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
989 		  struct net_device *dev,
990 		  const unsigned char *addr, u16 vid)
991 {
992 	struct net_bridge_vlan_group *vg;
993 	struct net_bridge_port *p = NULL;
994 	struct net_bridge_vlan *v;
995 	struct net_bridge *br = NULL;
996 	int err;
997 
998 	if (dev->priv_flags & IFF_EBRIDGE) {
999 		br = netdev_priv(dev);
1000 		vg = br_vlan_group(br);
1001 	} else {
1002 		p = br_port_get_rtnl(dev);
1003 		if (!p) {
1004 			pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1005 				dev->name);
1006 			return -EINVAL;
1007 		}
1008 		vg = nbp_vlan_group(p);
1009 	}
1010 
1011 	if (vid) {
1012 		v = br_vlan_find(vg, vid);
1013 		if (!v) {
1014 			pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1015 			return -EINVAL;
1016 		}
1017 
1018 		if (dev->priv_flags & IFF_EBRIDGE)
1019 			err = __br_fdb_delete_by_addr(br, addr, vid);
1020 		else
1021 			err = __br_fdb_delete(p, addr, vid);
1022 	} else {
1023 		err = -ENOENT;
1024 		if (dev->priv_flags & IFF_EBRIDGE)
1025 			err = __br_fdb_delete_by_addr(br, addr, 0);
1026 		else
1027 			err &= __br_fdb_delete(p, addr, 0);
1028 
1029 		if (!vg || !vg->num_vlans)
1030 			goto out;
1031 
1032 		list_for_each_entry(v, &vg->vlan_list, vlist) {
1033 			if (!br_vlan_should_use(v))
1034 				continue;
1035 			if (dev->priv_flags & IFF_EBRIDGE)
1036 				err = __br_fdb_delete_by_addr(br, addr, v->vid);
1037 			else
1038 				err &= __br_fdb_delete(p, addr, v->vid);
1039 		}
1040 	}
1041 out:
1042 	return err;
1043 }
1044 
br_fdb_sync_static(struct net_bridge * br,struct net_bridge_port * p)1045 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1046 {
1047 	struct net_bridge_fdb_entry *fdb, *tmp;
1048 	int i;
1049 	int err;
1050 
1051 	ASSERT_RTNL();
1052 
1053 	for (i = 0; i < BR_HASH_SIZE; i++) {
1054 		hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1055 			/* We only care for static entries */
1056 			if (!fdb->is_static)
1057 				continue;
1058 
1059 			err = dev_uc_add(p->dev, fdb->addr.addr);
1060 			if (err)
1061 				goto rollback;
1062 		}
1063 	}
1064 	return 0;
1065 
1066 rollback:
1067 	for (i = 0; i < BR_HASH_SIZE; i++) {
1068 		hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1069 			/* If we reached the fdb that failed, we can stop */
1070 			if (tmp == fdb)
1071 				break;
1072 
1073 			/* We only care for static entries */
1074 			if (!tmp->is_static)
1075 				continue;
1076 
1077 			dev_uc_del(p->dev, tmp->addr.addr);
1078 		}
1079 	}
1080 	return err;
1081 }
1082 
br_fdb_unsync_static(struct net_bridge * br,struct net_bridge_port * p)1083 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1084 {
1085 	struct net_bridge_fdb_entry *fdb;
1086 	int i;
1087 
1088 	ASSERT_RTNL();
1089 
1090 	for (i = 0; i < BR_HASH_SIZE; i++) {
1091 		hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1092 			/* We only care for static entries */
1093 			if (!fdb->is_static)
1094 				continue;
1095 
1096 			dev_uc_del(p->dev, fdb->addr.addr);
1097 		}
1098 	}
1099 }
1100 
br_fdb_external_learn_add(struct net_bridge * br,struct net_bridge_port * p,const unsigned char * addr,u16 vid)1101 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1102 			      const unsigned char *addr, u16 vid)
1103 {
1104 	struct hlist_head *head;
1105 	struct net_bridge_fdb_entry *fdb;
1106 	int err = 0;
1107 
1108 	ASSERT_RTNL();
1109 	spin_lock_bh(&br->hash_lock);
1110 
1111 	head = &br->hash[br_mac_hash(addr, vid)];
1112 	fdb = fdb_find(head, addr, vid);
1113 	if (!fdb) {
1114 		fdb = fdb_create(head, p, addr, vid, 0, 0);
1115 		if (!fdb) {
1116 			err = -ENOMEM;
1117 			goto err_unlock;
1118 		}
1119 		fdb->added_by_external_learn = 1;
1120 		fdb_notify(br, fdb, RTM_NEWNEIGH);
1121 	} else if (fdb->added_by_external_learn) {
1122 		/* Refresh entry */
1123 		fdb->updated = fdb->used = jiffies;
1124 	} else if (!fdb->added_by_user) {
1125 		/* Take over SW learned entry */
1126 		fdb->added_by_external_learn = 1;
1127 		fdb->updated = jiffies;
1128 		fdb_notify(br, fdb, RTM_NEWNEIGH);
1129 	}
1130 
1131 err_unlock:
1132 	spin_unlock_bh(&br->hash_lock);
1133 
1134 	return err;
1135 }
1136 
br_fdb_external_learn_del(struct net_bridge * br,struct net_bridge_port * p,const unsigned char * addr,u16 vid)1137 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1138 			      const unsigned char *addr, u16 vid)
1139 {
1140 	struct hlist_head *head;
1141 	struct net_bridge_fdb_entry *fdb;
1142 	int err = 0;
1143 
1144 	ASSERT_RTNL();
1145 	spin_lock_bh(&br->hash_lock);
1146 
1147 	head = &br->hash[br_mac_hash(addr, vid)];
1148 	fdb = fdb_find(head, addr, vid);
1149 	if (fdb && fdb->added_by_external_learn)
1150 		fdb_delete(br, fdb);
1151 	else
1152 		err = -ENOENT;
1153 
1154 	spin_unlock_bh(&br->hash_lock);
1155 
1156 	return err;
1157 }
1158