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