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1 /*
2  *	Forwarding database
3  *	Linux ethernet bridge
4  *
5  *	Authors:
6  *	Lennert Buytenhek		<buytenh@gnu.org>
7  *
8  *	This program is free software; you can redistribute it and/or
9  *	modify it under the terms of the GNU General Public License
10  *	as published by the Free Software Foundation; either version
11  *	2 of the License, or (at your option) any later version.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/rculist.h>
17 #include <linux/spinlock.h>
18 #include <linux/times.h>
19 #include <linux/netdevice.h>
20 #include <linux/etherdevice.h>
21 #include <linux/jhash.h>
22 #include <linux/random.h>
23 #include <linux/slab.h>
24 #include <linux/atomic.h>
25 #include <asm/unaligned.h>
26 #include <linux/if_vlan.h>
27 #include "br_private.h"
28 
29 static struct kmem_cache *br_fdb_cache __read_mostly;
30 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
31 					     const unsigned char *addr,
32 					     __u16 vid);
33 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
34 		      const unsigned char *addr, u16 vid);
35 static void fdb_notify(struct net_bridge *br,
36 		       const struct net_bridge_fdb_entry *, int);
37 
38 static u32 fdb_salt __read_mostly;
39 
br_fdb_init(void)40 int __init br_fdb_init(void)
41 {
42 	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
43 					 sizeof(struct net_bridge_fdb_entry),
44 					 0,
45 					 SLAB_HWCACHE_ALIGN, NULL);
46 	if (!br_fdb_cache)
47 		return -ENOMEM;
48 
49 	get_random_bytes(&fdb_salt, sizeof(fdb_salt));
50 	return 0;
51 }
52 
br_fdb_fini(void)53 void br_fdb_fini(void)
54 {
55 	kmem_cache_destroy(br_fdb_cache);
56 }
57 
58 
59 /* if topology_changing then use forward_delay (default 15 sec)
60  * otherwise keep longer (default 5 minutes)
61  */
hold_time(const struct net_bridge * br)62 static inline unsigned long hold_time(const struct net_bridge *br)
63 {
64 	return br->topology_change ? br->forward_delay : br->ageing_time;
65 }
66 
has_expired(const struct net_bridge * br,const struct net_bridge_fdb_entry * fdb)67 static inline int has_expired(const struct net_bridge *br,
68 				  const struct net_bridge_fdb_entry *fdb)
69 {
70 	return !fdb->is_static &&
71 		time_before_eq(fdb->updated + hold_time(br), jiffies);
72 }
73 
br_mac_hash(const unsigned char * mac,__u16 vid)74 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
75 {
76 	/* use 1 byte of OUI and 3 bytes of NIC */
77 	u32 key = get_unaligned((u32 *)(mac + 2));
78 	return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
79 }
80 
fdb_rcu_free(struct rcu_head * head)81 static void fdb_rcu_free(struct rcu_head *head)
82 {
83 	struct net_bridge_fdb_entry *ent
84 		= container_of(head, struct net_bridge_fdb_entry, rcu);
85 	kmem_cache_free(br_fdb_cache, ent);
86 }
87 
88 /* When a static FDB entry is added, the mac address from the entry is
89  * added to the bridge private HW address list and all required ports
90  * are then updated with the new information.
91  * Called under RTNL.
92  */
fdb_add_hw(struct net_bridge * br,const unsigned char * addr)93 static void fdb_add_hw(struct net_bridge *br, const unsigned char *addr)
94 {
95 	int err;
96 	struct net_bridge_port *p;
97 
98 	ASSERT_RTNL();
99 
100 	list_for_each_entry(p, &br->port_list, list) {
101 		if (!br_promisc_port(p)) {
102 			err = dev_uc_add(p->dev, addr);
103 			if (err)
104 				goto undo;
105 		}
106 	}
107 
108 	return;
109 undo:
110 	list_for_each_entry_continue_reverse(p, &br->port_list, list) {
111 		if (!br_promisc_port(p))
112 			dev_uc_del(p->dev, addr);
113 	}
114 }
115 
116 /* When a static FDB entry is deleted, the HW address from that entry is
117  * also removed from the bridge private HW address list and updates all
118  * the ports with needed information.
119  * Called under RTNL.
120  */
fdb_del_hw(struct net_bridge * br,const unsigned char * addr)121 static void fdb_del_hw(struct net_bridge *br, const unsigned char *addr)
122 {
123 	struct net_bridge_port *p;
124 
125 	ASSERT_RTNL();
126 
127 	list_for_each_entry(p, &br->port_list, list) {
128 		if (!br_promisc_port(p))
129 			dev_uc_del(p->dev, addr);
130 	}
131 }
132 
fdb_delete(struct net_bridge * br,struct net_bridge_fdb_entry * f)133 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
134 {
135 	if (f->is_static)
136 		fdb_del_hw(br, f->addr.addr);
137 
138 	hlist_del_rcu(&f->hlist);
139 	fdb_notify(br, f, RTM_DELNEIGH);
140 	call_rcu(&f->rcu, fdb_rcu_free);
141 }
142 
143 /* Delete a local entry if no other port had the same address. */
fdb_delete_local(struct net_bridge * br,const struct net_bridge_port * p,struct net_bridge_fdb_entry * f)144 static void fdb_delete_local(struct net_bridge *br,
145 			     const struct net_bridge_port *p,
146 			     struct net_bridge_fdb_entry *f)
147 {
148 	const unsigned char *addr = f->addr.addr;
149 	u16 vid = f->vlan_id;
150 	struct net_bridge_port *op;
151 
152 	/* Maybe another port has same hw addr? */
153 	list_for_each_entry(op, &br->port_list, list) {
154 		if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
155 		    (!vid || nbp_vlan_find(op, vid))) {
156 			f->dst = op;
157 			f->added_by_user = 0;
158 			return;
159 		}
160 	}
161 
162 	/* Maybe bridge device has same hw addr? */
163 	if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
164 	    (!vid || br_vlan_find(br, vid))) {
165 		f->dst = NULL;
166 		f->added_by_user = 0;
167 		return;
168 	}
169 
170 	fdb_delete(br, f);
171 }
172 
br_fdb_find_delete_local(struct net_bridge * br,const struct net_bridge_port * p,const unsigned char * addr,u16 vid)173 void br_fdb_find_delete_local(struct net_bridge *br,
174 			      const struct net_bridge_port *p,
175 			      const unsigned char *addr, u16 vid)
176 {
177 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
178 	struct net_bridge_fdb_entry *f;
179 
180 	spin_lock_bh(&br->hash_lock);
181 	f = fdb_find(head, addr, vid);
182 	if (f && f->is_local && !f->added_by_user && f->dst == p)
183 		fdb_delete_local(br, p, f);
184 	spin_unlock_bh(&br->hash_lock);
185 }
186 
br_fdb_changeaddr(struct net_bridge_port * p,const unsigned char * newaddr)187 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
188 {
189 	struct net_bridge *br = p->br;
190 	struct net_port_vlans *pv = nbp_get_vlan_info(p);
191 	bool no_vlan = !pv;
192 	int i;
193 	u16 vid;
194 
195 	spin_lock_bh(&br->hash_lock);
196 
197 	/* Search all chains since old address/hash is unknown */
198 	for (i = 0; i < BR_HASH_SIZE; i++) {
199 		struct hlist_node *h;
200 		hlist_for_each(h, &br->hash[i]) {
201 			struct net_bridge_fdb_entry *f;
202 
203 			f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
204 			if (f->dst == p && f->is_local && !f->added_by_user) {
205 				/* delete old one */
206 				fdb_delete_local(br, p, f);
207 
208 				/* if this port has no vlan information
209 				 * configured, we can safely be done at
210 				 * this point.
211 				 */
212 				if (no_vlan)
213 					goto insert;
214 			}
215 		}
216 	}
217 
218 insert:
219 	/* insert new address,  may fail if invalid address or dup. */
220 	fdb_insert(br, p, newaddr, 0);
221 
222 	if (no_vlan)
223 		goto done;
224 
225 	/* Now add entries for every VLAN configured on the port.
226 	 * This function runs under RTNL so the bitmap will not change
227 	 * from under us.
228 	 */
229 	for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
230 		fdb_insert(br, p, newaddr, vid);
231 
232 done:
233 	spin_unlock_bh(&br->hash_lock);
234 }
235 
br_fdb_change_mac_address(struct net_bridge * br,const u8 * newaddr)236 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
237 {
238 	struct net_bridge_fdb_entry *f;
239 	struct net_port_vlans *pv;
240 	u16 vid = 0;
241 
242 	spin_lock_bh(&br->hash_lock);
243 
244 	/* If old entry was unassociated with any port, then delete it. */
245 	f = __br_fdb_get(br, br->dev->dev_addr, 0);
246 	if (f && f->is_local && !f->dst)
247 		fdb_delete_local(br, NULL, f);
248 
249 	fdb_insert(br, NULL, newaddr, 0);
250 
251 	/* Now remove and add entries for every VLAN configured on the
252 	 * bridge.  This function runs under RTNL so the bitmap will not
253 	 * change from under us.
254 	 */
255 	pv = br_get_vlan_info(br);
256 	if (!pv)
257 		goto out;
258 
259 	for_each_set_bit_from(vid, pv->vlan_bitmap, VLAN_N_VID) {
260 		f = __br_fdb_get(br, br->dev->dev_addr, vid);
261 		if (f && f->is_local && !f->dst)
262 			fdb_delete_local(br, NULL, f);
263 		fdb_insert(br, NULL, newaddr, vid);
264 	}
265 out:
266 	spin_unlock_bh(&br->hash_lock);
267 }
268 
br_fdb_cleanup(unsigned long _data)269 void br_fdb_cleanup(unsigned long _data)
270 {
271 	struct net_bridge *br = (struct net_bridge *)_data;
272 	unsigned long delay = hold_time(br);
273 	unsigned long next_timer = jiffies + br->ageing_time;
274 	int i;
275 
276 	spin_lock(&br->hash_lock);
277 	for (i = 0; i < BR_HASH_SIZE; i++) {
278 		struct net_bridge_fdb_entry *f;
279 		struct hlist_node *n;
280 
281 		hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
282 			unsigned long this_timer;
283 			if (f->is_static)
284 				continue;
285 			this_timer = f->updated + delay;
286 			if (time_before_eq(this_timer, jiffies))
287 				fdb_delete(br, f);
288 			else if (time_before(this_timer, next_timer))
289 				next_timer = this_timer;
290 		}
291 	}
292 	spin_unlock(&br->hash_lock);
293 
294 	mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
295 }
296 
297 /* Completely flush all dynamic entries in forwarding database.*/
br_fdb_flush(struct net_bridge * br)298 void br_fdb_flush(struct net_bridge *br)
299 {
300 	int i;
301 
302 	spin_lock_bh(&br->hash_lock);
303 	for (i = 0; i < BR_HASH_SIZE; i++) {
304 		struct net_bridge_fdb_entry *f;
305 		struct hlist_node *n;
306 		hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
307 			if (!f->is_static)
308 				fdb_delete(br, f);
309 		}
310 	}
311 	spin_unlock_bh(&br->hash_lock);
312 }
313 
314 /* Flush all entries referring to a specific port.
315  * if do_all is set also flush static entries
316  */
br_fdb_delete_by_port(struct net_bridge * br,const struct net_bridge_port * p,int do_all)317 void br_fdb_delete_by_port(struct net_bridge *br,
318 			   const struct net_bridge_port *p,
319 			   int do_all)
320 {
321 	int i;
322 
323 	spin_lock_bh(&br->hash_lock);
324 	for (i = 0; i < BR_HASH_SIZE; i++) {
325 		struct hlist_node *h, *g;
326 
327 		hlist_for_each_safe(h, g, &br->hash[i]) {
328 			struct net_bridge_fdb_entry *f
329 				= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
330 			if (f->dst != p)
331 				continue;
332 
333 			if (f->is_static && !do_all)
334 				continue;
335 
336 			if (f->is_local)
337 				fdb_delete_local(br, p, f);
338 			else
339 				fdb_delete(br, f);
340 		}
341 	}
342 	spin_unlock_bh(&br->hash_lock);
343 }
344 
345 /* No locking or refcounting, assumes caller has rcu_read_lock */
__br_fdb_get(struct net_bridge * br,const unsigned char * addr,__u16 vid)346 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
347 					  const unsigned char *addr,
348 					  __u16 vid)
349 {
350 	struct net_bridge_fdb_entry *fdb;
351 
352 	hlist_for_each_entry_rcu(fdb,
353 				&br->hash[br_mac_hash(addr, vid)], hlist) {
354 		if (ether_addr_equal(fdb->addr.addr, addr) &&
355 		    fdb->vlan_id == vid) {
356 			if (unlikely(has_expired(br, fdb)))
357 				break;
358 			return fdb;
359 		}
360 	}
361 
362 	return NULL;
363 }
364 
365 #if IS_ENABLED(CONFIG_ATM_LANE)
366 /* Interface used by ATM LANE hook to test
367  * if an addr is on some other bridge port */
br_fdb_test_addr(struct net_device * dev,unsigned char * addr)368 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
369 {
370 	struct net_bridge_fdb_entry *fdb;
371 	struct net_bridge_port *port;
372 	int ret;
373 
374 	rcu_read_lock();
375 	port = br_port_get_rcu(dev);
376 	if (!port)
377 		ret = 0;
378 	else {
379 		fdb = __br_fdb_get(port->br, addr, 0);
380 		ret = fdb && fdb->dst && fdb->dst->dev != dev &&
381 			fdb->dst->state == BR_STATE_FORWARDING;
382 	}
383 	rcu_read_unlock();
384 
385 	return ret;
386 }
387 #endif /* CONFIG_ATM_LANE */
388 
389 /*
390  * Fill buffer with forwarding table records in
391  * the API format.
392  */
br_fdb_fillbuf(struct net_bridge * br,void * buf,unsigned long maxnum,unsigned long skip)393 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
394 		   unsigned long maxnum, unsigned long skip)
395 {
396 	struct __fdb_entry *fe = buf;
397 	int i, num = 0;
398 	struct net_bridge_fdb_entry *f;
399 
400 	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
401 
402 	rcu_read_lock();
403 	for (i = 0; i < BR_HASH_SIZE; i++) {
404 		hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
405 			if (num >= maxnum)
406 				goto out;
407 
408 			if (has_expired(br, f))
409 				continue;
410 
411 			/* ignore pseudo entry for local MAC address */
412 			if (!f->dst)
413 				continue;
414 
415 			if (skip) {
416 				--skip;
417 				continue;
418 			}
419 
420 			/* convert from internal format to API */
421 			memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
422 
423 			/* due to ABI compat need to split into hi/lo */
424 			fe->port_no = f->dst->port_no;
425 			fe->port_hi = f->dst->port_no >> 8;
426 
427 			fe->is_local = f->is_local;
428 			if (!f->is_static)
429 				fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
430 			++fe;
431 			++num;
432 		}
433 	}
434 
435  out:
436 	rcu_read_unlock();
437 
438 	return num;
439 }
440 
fdb_find(struct hlist_head * head,const unsigned char * addr,__u16 vid)441 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
442 					     const unsigned char *addr,
443 					     __u16 vid)
444 {
445 	struct net_bridge_fdb_entry *fdb;
446 
447 	hlist_for_each_entry(fdb, head, hlist) {
448 		if (ether_addr_equal(fdb->addr.addr, addr) &&
449 		    fdb->vlan_id == vid)
450 			return fdb;
451 	}
452 	return NULL;
453 }
454 
fdb_find_rcu(struct hlist_head * head,const unsigned char * addr,__u16 vid)455 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
456 						 const unsigned char *addr,
457 						 __u16 vid)
458 {
459 	struct net_bridge_fdb_entry *fdb;
460 
461 	hlist_for_each_entry_rcu(fdb, head, hlist) {
462 		if (ether_addr_equal(fdb->addr.addr, addr) &&
463 		    fdb->vlan_id == vid)
464 			return fdb;
465 	}
466 	return NULL;
467 }
468 
fdb_create(struct hlist_head * head,struct net_bridge_port * source,const unsigned char * addr,__u16 vid)469 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
470 					       struct net_bridge_port *source,
471 					       const unsigned char *addr,
472 					       __u16 vid)
473 {
474 	struct net_bridge_fdb_entry *fdb;
475 
476 	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
477 	if (fdb) {
478 		memcpy(fdb->addr.addr, addr, ETH_ALEN);
479 		fdb->dst = source;
480 		fdb->vlan_id = vid;
481 		fdb->is_local = 0;
482 		fdb->is_static = 0;
483 		fdb->added_by_user = 0;
484 		fdb->updated = fdb->used = jiffies;
485 		hlist_add_head_rcu(&fdb->hlist, head);
486 	}
487 	return fdb;
488 }
489 
fdb_insert(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid)490 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
491 		  const unsigned char *addr, u16 vid)
492 {
493 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
494 	struct net_bridge_fdb_entry *fdb;
495 
496 	if (!is_valid_ether_addr(addr))
497 		return -EINVAL;
498 
499 	fdb = fdb_find(head, addr, vid);
500 	if (fdb) {
501 		/* it is okay to have multiple ports with same
502 		 * address, just use the first one.
503 		 */
504 		if (fdb->is_local)
505 			return 0;
506 		br_warn(br, "adding interface %s with same address "
507 		       "as a received packet\n",
508 		       source ? source->dev->name : br->dev->name);
509 		fdb_delete(br, fdb);
510 	}
511 
512 	fdb = fdb_create(head, source, addr, vid);
513 	if (!fdb)
514 		return -ENOMEM;
515 
516 	fdb->is_local = fdb->is_static = 1;
517 	fdb_add_hw(br, addr);
518 	fdb_notify(br, fdb, RTM_NEWNEIGH);
519 	return 0;
520 }
521 
522 /* Add entry for local address of interface */
br_fdb_insert(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid)523 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
524 		  const unsigned char *addr, u16 vid)
525 {
526 	int ret;
527 
528 	spin_lock_bh(&br->hash_lock);
529 	ret = fdb_insert(br, source, addr, vid);
530 	spin_unlock_bh(&br->hash_lock);
531 	return ret;
532 }
533 
br_fdb_update(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid,bool added_by_user)534 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
535 		   const unsigned char *addr, u16 vid, bool added_by_user)
536 {
537 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
538 	struct net_bridge_fdb_entry *fdb;
539 	bool fdb_modified = false;
540 
541 	/* some users want to always flood. */
542 	if (hold_time(br) == 0)
543 		return;
544 
545 	/* ignore packets unless we are using this port */
546 	if (!(source->state == BR_STATE_LEARNING ||
547 	      source->state == BR_STATE_FORWARDING))
548 		return;
549 
550 	fdb = fdb_find_rcu(head, addr, vid);
551 	if (likely(fdb)) {
552 		/* attempt to update an entry for a local interface */
553 		if (unlikely(fdb->is_local)) {
554 			if (net_ratelimit())
555 				br_warn(br, "received packet on %s with "
556 					"own address as source address\n",
557 					source->dev->name);
558 		} else {
559 			/* fastpath: update of existing entry */
560 			if (unlikely(source != fdb->dst)) {
561 				fdb->dst = source;
562 				fdb_modified = true;
563 			}
564 			fdb->updated = jiffies;
565 			if (unlikely(added_by_user))
566 				fdb->added_by_user = 1;
567 			if (unlikely(fdb_modified))
568 				fdb_notify(br, fdb, RTM_NEWNEIGH);
569 		}
570 	} else {
571 		spin_lock(&br->hash_lock);
572 		if (likely(!fdb_find(head, addr, vid))) {
573 			fdb = fdb_create(head, source, addr, vid);
574 			if (fdb) {
575 				if (unlikely(added_by_user))
576 					fdb->added_by_user = 1;
577 				fdb_notify(br, fdb, RTM_NEWNEIGH);
578 			}
579 		}
580 		/* else  we lose race and someone else inserts
581 		 * it first, don't bother updating
582 		 */
583 		spin_unlock(&br->hash_lock);
584 	}
585 }
586 
fdb_to_nud(const struct net_bridge_fdb_entry * fdb)587 static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
588 {
589 	if (fdb->is_local)
590 		return NUD_PERMANENT;
591 	else if (fdb->is_static)
592 		return NUD_NOARP;
593 	else if (has_expired(fdb->dst->br, fdb))
594 		return NUD_STALE;
595 	else
596 		return NUD_REACHABLE;
597 }
598 
fdb_fill_info(struct sk_buff * skb,const struct net_bridge * br,const struct net_bridge_fdb_entry * fdb,u32 portid,u32 seq,int type,unsigned int flags)599 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
600 			 const struct net_bridge_fdb_entry *fdb,
601 			 u32 portid, u32 seq, int type, unsigned int flags)
602 {
603 	unsigned long now = jiffies;
604 	struct nda_cacheinfo ci;
605 	struct nlmsghdr *nlh;
606 	struct ndmsg *ndm;
607 
608 	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
609 	if (nlh == NULL)
610 		return -EMSGSIZE;
611 
612 	ndm = nlmsg_data(nlh);
613 	ndm->ndm_family	 = AF_BRIDGE;
614 	ndm->ndm_pad1    = 0;
615 	ndm->ndm_pad2    = 0;
616 	ndm->ndm_flags	 = 0;
617 	ndm->ndm_type	 = 0;
618 	ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
619 	ndm->ndm_state   = fdb_to_nud(fdb);
620 
621 	if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
622 		goto nla_put_failure;
623 	if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
624 		goto nla_put_failure;
625 	ci.ndm_used	 = jiffies_to_clock_t(now - fdb->used);
626 	ci.ndm_confirmed = 0;
627 	ci.ndm_updated	 = jiffies_to_clock_t(now - fdb->updated);
628 	ci.ndm_refcnt	 = 0;
629 	if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
630 		goto nla_put_failure;
631 
632 	if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
633 		goto nla_put_failure;
634 
635 	return nlmsg_end(skb, nlh);
636 
637 nla_put_failure:
638 	nlmsg_cancel(skb, nlh);
639 	return -EMSGSIZE;
640 }
641 
fdb_nlmsg_size(void)642 static inline size_t fdb_nlmsg_size(void)
643 {
644 	return NLMSG_ALIGN(sizeof(struct ndmsg))
645 		+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
646 		+ nla_total_size(sizeof(u32)) /* NDA_MASTER */
647 		+ nla_total_size(sizeof(u16)) /* NDA_VLAN */
648 		+ nla_total_size(sizeof(struct nda_cacheinfo));
649 }
650 
fdb_notify(struct net_bridge * br,const struct net_bridge_fdb_entry * fdb,int type)651 static void fdb_notify(struct net_bridge *br,
652 		       const struct net_bridge_fdb_entry *fdb, int type)
653 {
654 	struct net *net = dev_net(br->dev);
655 	struct sk_buff *skb;
656 	int err = -ENOBUFS;
657 
658 	skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
659 	if (skb == NULL)
660 		goto errout;
661 
662 	err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
663 	if (err < 0) {
664 		/* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
665 		WARN_ON(err == -EMSGSIZE);
666 		kfree_skb(skb);
667 		goto errout;
668 	}
669 	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
670 	return;
671 errout:
672 	rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
673 }
674 
675 /* Dump information about entries, in response to GETNEIGH */
br_fdb_dump(struct sk_buff * skb,struct netlink_callback * cb,struct net_device * dev,struct net_device * filter_dev,int idx)676 int br_fdb_dump(struct sk_buff *skb,
677 		struct netlink_callback *cb,
678 		struct net_device *dev,
679 		struct net_device *filter_dev,
680 		int idx)
681 {
682 	struct net_bridge *br = netdev_priv(dev);
683 	int i;
684 
685 	if (!(dev->priv_flags & IFF_EBRIDGE))
686 		goto out;
687 
688 	for (i = 0; i < BR_HASH_SIZE; i++) {
689 		struct net_bridge_fdb_entry *f;
690 
691 		hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
692 			if (idx < cb->args[0])
693 				goto skip;
694 
695 			if (filter_dev &&
696 			    (!f->dst || f->dst->dev != filter_dev)) {
697 				if (filter_dev != dev)
698 					goto skip;
699 				/* !f->dst is a speacial case for bridge
700 				 * It means the MAC belongs to the bridge
701 				 * Therefore need a little more filtering
702 				 * we only want to dump the !f->dst case
703 				 */
704 				if (f->dst)
705 					goto skip;
706 			}
707 
708 			if (fdb_fill_info(skb, br, f,
709 					  NETLINK_CB(cb->skb).portid,
710 					  cb->nlh->nlmsg_seq,
711 					  RTM_NEWNEIGH,
712 					  NLM_F_MULTI) < 0)
713 				break;
714 skip:
715 			++idx;
716 		}
717 	}
718 
719 out:
720 	return idx;
721 }
722 
723 /* Update (create or replace) forwarding database entry */
fdb_add_entry(struct net_bridge_port * source,const __u8 * addr,__u16 state,__u16 flags,__u16 vid)724 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
725 			 __u16 state, __u16 flags, __u16 vid)
726 {
727 	struct net_bridge *br = source->br;
728 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
729 	struct net_bridge_fdb_entry *fdb;
730 	bool modified = false;
731 
732 	fdb = fdb_find(head, addr, vid);
733 	if (fdb == NULL) {
734 		if (!(flags & NLM_F_CREATE))
735 			return -ENOENT;
736 
737 		fdb = fdb_create(head, source, addr, vid);
738 		if (!fdb)
739 			return -ENOMEM;
740 
741 		modified = true;
742 	} else {
743 		if (flags & NLM_F_EXCL)
744 			return -EEXIST;
745 
746 		if (fdb->dst != source) {
747 			fdb->dst = source;
748 			modified = true;
749 		}
750 	}
751 
752 	if (fdb_to_nud(fdb) != state) {
753 		if (state & NUD_PERMANENT) {
754 			fdb->is_local = 1;
755 			if (!fdb->is_static) {
756 				fdb->is_static = 1;
757 				fdb_add_hw(br, addr);
758 			}
759 		} else if (state & NUD_NOARP) {
760 			fdb->is_local = 0;
761 			if (!fdb->is_static) {
762 				fdb->is_static = 1;
763 				fdb_add_hw(br, addr);
764 			}
765 		} else {
766 			fdb->is_local = 0;
767 			if (fdb->is_static) {
768 				fdb->is_static = 0;
769 				fdb_del_hw(br, addr);
770 			}
771 		}
772 
773 		modified = true;
774 	}
775 	fdb->added_by_user = 1;
776 
777 	fdb->used = jiffies;
778 	if (modified) {
779 		fdb->updated = jiffies;
780 		fdb_notify(br, fdb, RTM_NEWNEIGH);
781 	}
782 
783 	return 0;
784 }
785 
__br_fdb_add(struct ndmsg * ndm,struct net_bridge_port * p,const unsigned char * addr,u16 nlh_flags,u16 vid)786 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p,
787 	       const unsigned char *addr, u16 nlh_flags, u16 vid)
788 {
789 	int err = 0;
790 
791 	if (ndm->ndm_flags & NTF_USE) {
792 		local_bh_disable();
793 		rcu_read_lock();
794 		br_fdb_update(p->br, p, addr, vid, true);
795 		rcu_read_unlock();
796 		local_bh_enable();
797 	} else {
798 		spin_lock_bh(&p->br->hash_lock);
799 		err = fdb_add_entry(p, addr, ndm->ndm_state,
800 				    nlh_flags, vid);
801 		spin_unlock_bh(&p->br->hash_lock);
802 	}
803 
804 	return err;
805 }
806 
807 /* Add new permanent fdb entry with RTM_NEWNEIGH */
br_fdb_add(struct ndmsg * ndm,struct nlattr * tb[],struct net_device * dev,const unsigned char * addr,u16 nlh_flags)808 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
809 	       struct net_device *dev,
810 	       const unsigned char *addr, u16 nlh_flags)
811 {
812 	struct net_bridge_port *p;
813 	int err = 0;
814 	struct net_port_vlans *pv;
815 	unsigned short vid = VLAN_N_VID;
816 
817 	if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
818 		pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
819 		return -EINVAL;
820 	}
821 
822 	if (tb[NDA_VLAN]) {
823 		if (nla_len(tb[NDA_VLAN]) != sizeof(unsigned short)) {
824 			pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
825 			return -EINVAL;
826 		}
827 
828 		vid = nla_get_u16(tb[NDA_VLAN]);
829 
830 		if (!vid || vid >= VLAN_VID_MASK) {
831 			pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
832 				vid);
833 			return -EINVAL;
834 		}
835 	}
836 
837 	if (is_zero_ether_addr(addr)) {
838 		pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
839 		return -EINVAL;
840 	}
841 
842 	p = br_port_get_rtnl(dev);
843 	if (p == NULL) {
844 		pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
845 			dev->name);
846 		return -EINVAL;
847 	}
848 
849 	pv = nbp_get_vlan_info(p);
850 	if (vid != VLAN_N_VID) {
851 		if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
852 			pr_info("bridge: RTM_NEWNEIGH with unconfigured "
853 				"vlan %d on port %s\n", vid, dev->name);
854 			return -EINVAL;
855 		}
856 
857 		/* VID was specified, so use it. */
858 		err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
859 	} else {
860 		if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID)) {
861 			err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
862 			goto out;
863 		}
864 
865 		/* We have vlans configured on this port and user didn't
866 		 * specify a VLAN.  To be nice, add/update entry for every
867 		 * vlan on this port.
868 		 */
869 		for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
870 			err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
871 			if (err)
872 				goto out;
873 		}
874 	}
875 
876 out:
877 	return err;
878 }
879 
fdb_delete_by_addr(struct net_bridge * br,const u8 * addr,u16 vlan)880 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr, u16 vlan)
881 {
882 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
883 	struct net_bridge_fdb_entry *fdb;
884 
885 	fdb = fdb_find(head, addr, vlan);
886 	if (!fdb)
887 		return -ENOENT;
888 
889 	fdb_delete(br, fdb);
890 	return 0;
891 }
892 
__br_fdb_delete(struct net_bridge_port * p,const unsigned char * addr,u16 vid)893 static int __br_fdb_delete(struct net_bridge_port *p,
894 			   const unsigned char *addr, u16 vid)
895 {
896 	int err;
897 
898 	spin_lock_bh(&p->br->hash_lock);
899 	err = fdb_delete_by_addr(p->br, addr, vid);
900 	spin_unlock_bh(&p->br->hash_lock);
901 
902 	return err;
903 }
904 
905 /* Remove neighbor entry with RTM_DELNEIGH */
br_fdb_delete(struct ndmsg * ndm,struct nlattr * tb[],struct net_device * dev,const unsigned char * addr)906 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
907 		  struct net_device *dev,
908 		  const unsigned char *addr)
909 {
910 	struct net_bridge_port *p;
911 	int err;
912 	struct net_port_vlans *pv;
913 	unsigned short vid = VLAN_N_VID;
914 
915 	if (tb[NDA_VLAN]) {
916 		if (nla_len(tb[NDA_VLAN]) != sizeof(unsigned short)) {
917 			pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
918 			return -EINVAL;
919 		}
920 
921 		vid = nla_get_u16(tb[NDA_VLAN]);
922 
923 		if (!vid || vid >= VLAN_VID_MASK) {
924 			pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
925 				vid);
926 			return -EINVAL;
927 		}
928 	}
929 	p = br_port_get_rtnl(dev);
930 	if (p == NULL) {
931 		pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
932 			dev->name);
933 		return -EINVAL;
934 	}
935 
936 	pv = nbp_get_vlan_info(p);
937 	if (vid != VLAN_N_VID) {
938 		if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
939 			pr_info("bridge: RTM_DELNEIGH with unconfigured "
940 				"vlan %d on port %s\n", vid, dev->name);
941 			return -EINVAL;
942 		}
943 
944 		err = __br_fdb_delete(p, addr, vid);
945 	} else {
946 		if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID)) {
947 			err = __br_fdb_delete(p, addr, 0);
948 			goto out;
949 		}
950 
951 		/* We have vlans configured on this port and user didn't
952 		 * specify a VLAN.  To be nice, add/update entry for every
953 		 * vlan on this port.
954 		 */
955 		err = -ENOENT;
956 		for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
957 			err &= __br_fdb_delete(p, addr, vid);
958 		}
959 	}
960 out:
961 	return err;
962 }
963 
br_fdb_sync_static(struct net_bridge * br,struct net_bridge_port * p)964 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
965 {
966 	struct net_bridge_fdb_entry *fdb, *tmp;
967 	int i;
968 	int err;
969 
970 	ASSERT_RTNL();
971 
972 	for (i = 0; i < BR_HASH_SIZE; i++) {
973 		hlist_for_each_entry(fdb, &br->hash[i], hlist) {
974 			/* We only care for static entries */
975 			if (!fdb->is_static)
976 				continue;
977 
978 			err = dev_uc_add(p->dev, fdb->addr.addr);
979 			if (err)
980 				goto rollback;
981 		}
982 	}
983 	return 0;
984 
985 rollback:
986 	for (i = 0; i < BR_HASH_SIZE; i++) {
987 		hlist_for_each_entry(tmp, &br->hash[i], hlist) {
988 			/* If we reached the fdb that failed, we can stop */
989 			if (tmp == fdb)
990 				break;
991 
992 			/* We only care for static entries */
993 			if (!tmp->is_static)
994 				continue;
995 
996 			dev_uc_del(p->dev, tmp->addr.addr);
997 		}
998 	}
999 	return err;
1000 }
1001 
br_fdb_unsync_static(struct net_bridge * br,struct net_bridge_port * p)1002 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1003 {
1004 	struct net_bridge_fdb_entry *fdb;
1005 	int i;
1006 
1007 	ASSERT_RTNL();
1008 
1009 	for (i = 0; i < BR_HASH_SIZE; i++) {
1010 		hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1011 			/* We only care for static entries */
1012 			if (!fdb->is_static)
1013 				continue;
1014 
1015 			dev_uc_del(p->dev, fdb->addr.addr);
1016 		}
1017 	}
1018 }
1019