1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	Forwarding database
4  *	Linux ethernet bridge
5  *
6  *	Authors:
7  *	Lennert Buytenhek		<buytenh@gnu.org>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/rculist.h>
13 #include <linux/spinlock.h>
14 #include <linux/times.h>
15 #include <linux/netdevice.h>
16 #include <linux/etherdevice.h>
17 #include <linux/jhash.h>
18 #include <linux/random.h>
19 #include <linux/slab.h>
20 #include <linux/atomic.h>
21 #include <asm/unaligned.h>
22 #include <linux/if_vlan.h>
23 #include <net/switchdev.h>
24 #include <trace/events/bridge.h>
25 #include "br_private.h"
26 
27 static const struct rhashtable_params br_fdb_rht_params = {
28 	.head_offset = offsetof(struct net_bridge_fdb_entry, rhnode),
29 	.key_offset = offsetof(struct net_bridge_fdb_entry, key),
30 	.key_len = sizeof(struct net_bridge_fdb_key),
31 	.automatic_shrinking = true,
32 };
33 
34 static struct kmem_cache *br_fdb_cache __read_mostly;
35 
br_fdb_init(void)36 int __init br_fdb_init(void)
37 {
38 	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
39 					 sizeof(struct net_bridge_fdb_entry),
40 					 0,
41 					 SLAB_HWCACHE_ALIGN, NULL);
42 	if (!br_fdb_cache)
43 		return -ENOMEM;
44 
45 	return 0;
46 }
47 
br_fdb_fini(void)48 void br_fdb_fini(void)
49 {
50 	kmem_cache_destroy(br_fdb_cache);
51 }
52 
br_fdb_hash_init(struct net_bridge * br)53 int br_fdb_hash_init(struct net_bridge *br)
54 {
55 	return rhashtable_init(&br->fdb_hash_tbl, &br_fdb_rht_params);
56 }
57 
br_fdb_hash_fini(struct net_bridge * br)58 void br_fdb_hash_fini(struct net_bridge *br)
59 {
60 	rhashtable_destroy(&br->fdb_hash_tbl);
61 }
62 
63 /* if topology_changing then use forward_delay (default 15 sec)
64  * otherwise keep longer (default 5 minutes)
65  */
hold_time(const struct net_bridge * br)66 static inline unsigned long hold_time(const struct net_bridge *br)
67 {
68 	return br->topology_change ? br->forward_delay : br->ageing_time;
69 }
70 
has_expired(const struct net_bridge * br,const struct net_bridge_fdb_entry * fdb)71 static inline int has_expired(const struct net_bridge *br,
72 				  const struct net_bridge_fdb_entry *fdb)
73 {
74 	return !test_bit(BR_FDB_STATIC, &fdb->flags) &&
75 	       !test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags) &&
76 	       time_before_eq(fdb->updated + hold_time(br), jiffies);
77 }
78 
fdb_rcu_free(struct rcu_head * head)79 static void fdb_rcu_free(struct rcu_head *head)
80 {
81 	struct net_bridge_fdb_entry *ent
82 		= container_of(head, struct net_bridge_fdb_entry, rcu);
83 	kmem_cache_free(br_fdb_cache, ent);
84 }
85 
fdb_to_nud(const struct net_bridge * br,const struct net_bridge_fdb_entry * fdb)86 static int fdb_to_nud(const struct net_bridge *br,
87 		      const struct net_bridge_fdb_entry *fdb)
88 {
89 	if (test_bit(BR_FDB_LOCAL, &fdb->flags))
90 		return NUD_PERMANENT;
91 	else if (test_bit(BR_FDB_STATIC, &fdb->flags))
92 		return NUD_NOARP;
93 	else if (has_expired(br, fdb))
94 		return NUD_STALE;
95 	else
96 		return NUD_REACHABLE;
97 }
98 
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)99 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
100 			 const struct net_bridge_fdb_entry *fdb,
101 			 u32 portid, u32 seq, int type, unsigned int flags)
102 {
103 	const struct net_bridge_port *dst = READ_ONCE(fdb->dst);
104 	unsigned long now = jiffies;
105 	struct nda_cacheinfo ci;
106 	struct nlmsghdr *nlh;
107 	struct ndmsg *ndm;
108 
109 	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
110 	if (nlh == NULL)
111 		return -EMSGSIZE;
112 
113 	ndm = nlmsg_data(nlh);
114 	ndm->ndm_family	 = AF_BRIDGE;
115 	ndm->ndm_pad1    = 0;
116 	ndm->ndm_pad2    = 0;
117 	ndm->ndm_flags	 = 0;
118 	ndm->ndm_type	 = 0;
119 	ndm->ndm_ifindex = dst ? dst->dev->ifindex : br->dev->ifindex;
120 	ndm->ndm_state   = fdb_to_nud(br, fdb);
121 
122 	if (test_bit(BR_FDB_OFFLOADED, &fdb->flags))
123 		ndm->ndm_flags |= NTF_OFFLOADED;
124 	if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
125 		ndm->ndm_flags |= NTF_EXT_LEARNED;
126 	if (test_bit(BR_FDB_STICKY, &fdb->flags))
127 		ndm->ndm_flags |= NTF_STICKY;
128 
129 	if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr))
130 		goto nla_put_failure;
131 	if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
132 		goto nla_put_failure;
133 	ci.ndm_used	 = jiffies_to_clock_t(now - fdb->used);
134 	ci.ndm_confirmed = 0;
135 	ci.ndm_updated	 = jiffies_to_clock_t(now - fdb->updated);
136 	ci.ndm_refcnt	 = 0;
137 	if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
138 		goto nla_put_failure;
139 
140 	if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16),
141 					&fdb->key.vlan_id))
142 		goto nla_put_failure;
143 
144 	if (test_bit(BR_FDB_NOTIFY, &fdb->flags)) {
145 		struct nlattr *nest = nla_nest_start(skb, NDA_FDB_EXT_ATTRS);
146 		u8 notify_bits = FDB_NOTIFY_BIT;
147 
148 		if (!nest)
149 			goto nla_put_failure;
150 		if (test_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags))
151 			notify_bits |= FDB_NOTIFY_INACTIVE_BIT;
152 
153 		if (nla_put_u8(skb, NFEA_ACTIVITY_NOTIFY, notify_bits)) {
154 			nla_nest_cancel(skb, nest);
155 			goto nla_put_failure;
156 		}
157 
158 		nla_nest_end(skb, nest);
159 	}
160 
161 	nlmsg_end(skb, nlh);
162 	return 0;
163 
164 nla_put_failure:
165 	nlmsg_cancel(skb, nlh);
166 	return -EMSGSIZE;
167 }
168 
fdb_nlmsg_size(void)169 static inline size_t fdb_nlmsg_size(void)
170 {
171 	return NLMSG_ALIGN(sizeof(struct ndmsg))
172 		+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
173 		+ nla_total_size(sizeof(u32)) /* NDA_MASTER */
174 		+ nla_total_size(sizeof(u16)) /* NDA_VLAN */
175 		+ nla_total_size(sizeof(struct nda_cacheinfo))
176 		+ nla_total_size(0) /* NDA_FDB_EXT_ATTRS */
177 		+ nla_total_size(sizeof(u8)); /* NFEA_ACTIVITY_NOTIFY */
178 }
179 
fdb_notify(struct net_bridge * br,const struct net_bridge_fdb_entry * fdb,int type,bool swdev_notify)180 static void fdb_notify(struct net_bridge *br,
181 		       const struct net_bridge_fdb_entry *fdb, int type,
182 		       bool swdev_notify)
183 {
184 	struct net *net = dev_net(br->dev);
185 	struct sk_buff *skb;
186 	int err = -ENOBUFS;
187 
188 	if (swdev_notify)
189 		br_switchdev_fdb_notify(br, fdb, type);
190 
191 	skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
192 	if (skb == NULL)
193 		goto errout;
194 
195 	err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
196 	if (err < 0) {
197 		/* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
198 		WARN_ON(err == -EMSGSIZE);
199 		kfree_skb(skb);
200 		goto errout;
201 	}
202 	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
203 	return;
204 errout:
205 	rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
206 }
207 
fdb_find_rcu(struct rhashtable * tbl,const unsigned char * addr,__u16 vid)208 static struct net_bridge_fdb_entry *fdb_find_rcu(struct rhashtable *tbl,
209 						 const unsigned char *addr,
210 						 __u16 vid)
211 {
212 	struct net_bridge_fdb_key key;
213 
214 	WARN_ON_ONCE(!rcu_read_lock_held());
215 
216 	key.vlan_id = vid;
217 	memcpy(key.addr.addr, addr, sizeof(key.addr.addr));
218 
219 	return rhashtable_lookup(tbl, &key, br_fdb_rht_params);
220 }
221 
222 /* requires bridge hash_lock */
br_fdb_find(struct net_bridge * br,const unsigned char * addr,__u16 vid)223 static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
224 						const unsigned char *addr,
225 						__u16 vid)
226 {
227 	struct net_bridge_fdb_entry *fdb;
228 
229 	lockdep_assert_held_once(&br->hash_lock);
230 
231 	rcu_read_lock();
232 	fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
233 	rcu_read_unlock();
234 
235 	return fdb;
236 }
237 
br_fdb_find_port(const struct net_device * br_dev,const unsigned char * addr,__u16 vid)238 struct net_device *br_fdb_find_port(const struct net_device *br_dev,
239 				    const unsigned char *addr,
240 				    __u16 vid)
241 {
242 	struct net_bridge_fdb_entry *f;
243 	struct net_device *dev = NULL;
244 	struct net_bridge *br;
245 
246 	ASSERT_RTNL();
247 
248 	if (!netif_is_bridge_master(br_dev))
249 		return NULL;
250 
251 	br = netdev_priv(br_dev);
252 	rcu_read_lock();
253 	f = br_fdb_find_rcu(br, addr, vid);
254 	if (f && f->dst)
255 		dev = f->dst->dev;
256 	rcu_read_unlock();
257 
258 	return dev;
259 }
260 EXPORT_SYMBOL_GPL(br_fdb_find_port);
261 
br_fdb_find_rcu(struct net_bridge * br,const unsigned char * addr,__u16 vid)262 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
263 					     const unsigned char *addr,
264 					     __u16 vid)
265 {
266 	return fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
267 }
268 
269 /* When a static FDB entry is added, the mac address from the entry is
270  * added to the bridge private HW address list and all required ports
271  * are then updated with the new information.
272  * Called under RTNL.
273  */
fdb_add_hw_addr(struct net_bridge * br,const unsigned char * addr)274 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
275 {
276 	int err;
277 	struct net_bridge_port *p;
278 
279 	ASSERT_RTNL();
280 
281 	list_for_each_entry(p, &br->port_list, list) {
282 		if (!br_promisc_port(p)) {
283 			err = dev_uc_add(p->dev, addr);
284 			if (err)
285 				goto undo;
286 		}
287 	}
288 
289 	return;
290 undo:
291 	list_for_each_entry_continue_reverse(p, &br->port_list, list) {
292 		if (!br_promisc_port(p))
293 			dev_uc_del(p->dev, addr);
294 	}
295 }
296 
297 /* When a static FDB entry is deleted, the HW address from that entry is
298  * also removed from the bridge private HW address list and updates all
299  * the ports with needed information.
300  * Called under RTNL.
301  */
fdb_del_hw_addr(struct net_bridge * br,const unsigned char * addr)302 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
303 {
304 	struct net_bridge_port *p;
305 
306 	ASSERT_RTNL();
307 
308 	list_for_each_entry(p, &br->port_list, list) {
309 		if (!br_promisc_port(p))
310 			dev_uc_del(p->dev, addr);
311 	}
312 }
313 
fdb_delete(struct net_bridge * br,struct net_bridge_fdb_entry * f,bool swdev_notify)314 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f,
315 		       bool swdev_notify)
316 {
317 	trace_fdb_delete(br, f);
318 
319 	if (test_bit(BR_FDB_STATIC, &f->flags))
320 		fdb_del_hw_addr(br, f->key.addr.addr);
321 
322 	hlist_del_init_rcu(&f->fdb_node);
323 	rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode,
324 			       br_fdb_rht_params);
325 	fdb_notify(br, f, RTM_DELNEIGH, swdev_notify);
326 	call_rcu(&f->rcu, fdb_rcu_free);
327 }
328 
329 /* 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)330 static void fdb_delete_local(struct net_bridge *br,
331 			     const struct net_bridge_port *p,
332 			     struct net_bridge_fdb_entry *f)
333 {
334 	const unsigned char *addr = f->key.addr.addr;
335 	struct net_bridge_vlan_group *vg;
336 	const struct net_bridge_vlan *v;
337 	struct net_bridge_port *op;
338 	u16 vid = f->key.vlan_id;
339 
340 	/* Maybe another port has same hw addr? */
341 	list_for_each_entry(op, &br->port_list, list) {
342 		vg = nbp_vlan_group(op);
343 		if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
344 		    (!vid || br_vlan_find(vg, vid))) {
345 			f->dst = op;
346 			clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
347 			return;
348 		}
349 	}
350 
351 	vg = br_vlan_group(br);
352 	v = br_vlan_find(vg, vid);
353 	/* Maybe bridge device has same hw addr? */
354 	if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
355 	    (!vid || (v && br_vlan_should_use(v)))) {
356 		f->dst = NULL;
357 		clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
358 		return;
359 	}
360 
361 	fdb_delete(br, f, true);
362 }
363 
br_fdb_find_delete_local(struct net_bridge * br,const struct net_bridge_port * p,const unsigned char * addr,u16 vid)364 void br_fdb_find_delete_local(struct net_bridge *br,
365 			      const struct net_bridge_port *p,
366 			      const unsigned char *addr, u16 vid)
367 {
368 	struct net_bridge_fdb_entry *f;
369 
370 	spin_lock_bh(&br->hash_lock);
371 	f = br_fdb_find(br, addr, vid);
372 	if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
373 	    !test_bit(BR_FDB_ADDED_BY_USER, &f->flags) && f->dst == p)
374 		fdb_delete_local(br, p, f);
375 	spin_unlock_bh(&br->hash_lock);
376 }
377 
fdb_create(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,__u16 vid,unsigned long flags)378 static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br,
379 					       struct net_bridge_port *source,
380 					       const unsigned char *addr,
381 					       __u16 vid,
382 					       unsigned long flags)
383 {
384 	struct net_bridge_fdb_entry *fdb;
385 	int err;
386 
387 	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
388 	if (!fdb)
389 		return NULL;
390 
391 	memcpy(fdb->key.addr.addr, addr, ETH_ALEN);
392 	WRITE_ONCE(fdb->dst, source);
393 	fdb->key.vlan_id = vid;
394 	fdb->flags = flags;
395 	fdb->updated = fdb->used = jiffies;
396 	err = rhashtable_lookup_insert_fast(&br->fdb_hash_tbl, &fdb->rhnode,
397 					    br_fdb_rht_params);
398 	if (err) {
399 		kmem_cache_free(br_fdb_cache, fdb);
400 		return NULL;
401 	}
402 
403 	hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list);
404 
405 	return fdb;
406 }
407 
fdb_add_local(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid)408 static int fdb_add_local(struct net_bridge *br, struct net_bridge_port *source,
409 			 const unsigned char *addr, u16 vid)
410 {
411 	struct net_bridge_fdb_entry *fdb;
412 
413 	if (!is_valid_ether_addr(addr))
414 		return -EINVAL;
415 
416 	fdb = br_fdb_find(br, addr, vid);
417 	if (fdb) {
418 		/* it is okay to have multiple ports with same
419 		 * address, just use the first one.
420 		 */
421 		if (test_bit(BR_FDB_LOCAL, &fdb->flags))
422 			return 0;
423 		br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
424 			source ? source->dev->name : br->dev->name, addr, vid);
425 		fdb_delete(br, fdb, true);
426 	}
427 
428 	fdb = fdb_create(br, source, addr, vid,
429 			 BIT(BR_FDB_LOCAL) | BIT(BR_FDB_STATIC));
430 	if (!fdb)
431 		return -ENOMEM;
432 
433 	fdb_add_hw_addr(br, addr);
434 	fdb_notify(br, fdb, RTM_NEWNEIGH, true);
435 	return 0;
436 }
437 
br_fdb_changeaddr(struct net_bridge_port * p,const unsigned char * newaddr)438 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
439 {
440 	struct net_bridge_vlan_group *vg;
441 	struct net_bridge_fdb_entry *f;
442 	struct net_bridge *br = p->br;
443 	struct net_bridge_vlan *v;
444 
445 	spin_lock_bh(&br->hash_lock);
446 	vg = nbp_vlan_group(p);
447 	hlist_for_each_entry(f, &br->fdb_list, fdb_node) {
448 		if (f->dst == p && test_bit(BR_FDB_LOCAL, &f->flags) &&
449 		    !test_bit(BR_FDB_ADDED_BY_USER, &f->flags)) {
450 			/* delete old one */
451 			fdb_delete_local(br, p, f);
452 
453 			/* if this port has no vlan information
454 			 * configured, we can safely be done at
455 			 * this point.
456 			 */
457 			if (!vg || !vg->num_vlans)
458 				goto insert;
459 		}
460 	}
461 
462 insert:
463 	/* insert new address,  may fail if invalid address or dup. */
464 	fdb_add_local(br, p, newaddr, 0);
465 
466 	if (!vg || !vg->num_vlans)
467 		goto done;
468 
469 	/* Now add entries for every VLAN configured on the port.
470 	 * This function runs under RTNL so the bitmap will not change
471 	 * from under us.
472 	 */
473 	list_for_each_entry(v, &vg->vlan_list, vlist)
474 		fdb_add_local(br, p, newaddr, v->vid);
475 
476 done:
477 	spin_unlock_bh(&br->hash_lock);
478 }
479 
br_fdb_change_mac_address(struct net_bridge * br,const u8 * newaddr)480 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
481 {
482 	struct net_bridge_vlan_group *vg;
483 	struct net_bridge_fdb_entry *f;
484 	struct net_bridge_vlan *v;
485 
486 	spin_lock_bh(&br->hash_lock);
487 
488 	/* If old entry was unassociated with any port, then delete it. */
489 	f = br_fdb_find(br, br->dev->dev_addr, 0);
490 	if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
491 	    !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags))
492 		fdb_delete_local(br, NULL, f);
493 
494 	fdb_add_local(br, NULL, newaddr, 0);
495 	vg = br_vlan_group(br);
496 	if (!vg || !vg->num_vlans)
497 		goto out;
498 	/* Now remove and add entries for every VLAN configured on the
499 	 * bridge.  This function runs under RTNL so the bitmap will not
500 	 * change from under us.
501 	 */
502 	list_for_each_entry(v, &vg->vlan_list, vlist) {
503 		if (!br_vlan_should_use(v))
504 			continue;
505 		f = br_fdb_find(br, br->dev->dev_addr, v->vid);
506 		if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
507 		    !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags))
508 			fdb_delete_local(br, NULL, f);
509 		fdb_add_local(br, NULL, newaddr, v->vid);
510 	}
511 out:
512 	spin_unlock_bh(&br->hash_lock);
513 }
514 
br_fdb_cleanup(struct work_struct * work)515 void br_fdb_cleanup(struct work_struct *work)
516 {
517 	struct net_bridge *br = container_of(work, struct net_bridge,
518 					     gc_work.work);
519 	struct net_bridge_fdb_entry *f = NULL;
520 	unsigned long delay = hold_time(br);
521 	unsigned long work_delay = delay;
522 	unsigned long now = jiffies;
523 
524 	/* this part is tricky, in order to avoid blocking learning and
525 	 * consequently forwarding, we rely on rcu to delete objects with
526 	 * delayed freeing allowing us to continue traversing
527 	 */
528 	rcu_read_lock();
529 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
530 		unsigned long this_timer = f->updated + delay;
531 
532 		if (test_bit(BR_FDB_STATIC, &f->flags) ||
533 		    test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags)) {
534 			if (test_bit(BR_FDB_NOTIFY, &f->flags)) {
535 				if (time_after(this_timer, now))
536 					work_delay = min(work_delay,
537 							 this_timer - now);
538 				else if (!test_and_set_bit(BR_FDB_NOTIFY_INACTIVE,
539 							   &f->flags))
540 					fdb_notify(br, f, RTM_NEWNEIGH, false);
541 			}
542 			continue;
543 		}
544 
545 		if (time_after(this_timer, now)) {
546 			work_delay = min(work_delay, this_timer - now);
547 		} else {
548 			spin_lock_bh(&br->hash_lock);
549 			if (!hlist_unhashed(&f->fdb_node))
550 				fdb_delete(br, f, true);
551 			spin_unlock_bh(&br->hash_lock);
552 		}
553 	}
554 	rcu_read_unlock();
555 
556 	/* Cleanup minimum 10 milliseconds apart */
557 	work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
558 	mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
559 }
560 
__fdb_flush_matches(const struct net_bridge * br,const struct net_bridge_fdb_entry * f,const struct net_bridge_fdb_flush_desc * desc)561 static bool __fdb_flush_matches(const struct net_bridge *br,
562 				const struct net_bridge_fdb_entry *f,
563 				const struct net_bridge_fdb_flush_desc *desc)
564 {
565 	const struct net_bridge_port *dst = READ_ONCE(f->dst);
566 	int port_ifidx = dst ? dst->dev->ifindex : br->dev->ifindex;
567 
568 	if (desc->vlan_id && desc->vlan_id != f->key.vlan_id)
569 		return false;
570 	if (desc->port_ifindex && desc->port_ifindex != port_ifidx)
571 		return false;
572 	if (desc->flags_mask && (f->flags & desc->flags_mask) != desc->flags)
573 		return false;
574 
575 	return true;
576 }
577 
578 /* Flush forwarding database entries matching the description */
br_fdb_flush(struct net_bridge * br,const struct net_bridge_fdb_flush_desc * desc)579 void br_fdb_flush(struct net_bridge *br,
580 		  const struct net_bridge_fdb_flush_desc *desc)
581 {
582 	struct net_bridge_fdb_entry *f;
583 
584 	rcu_read_lock();
585 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
586 		if (!__fdb_flush_matches(br, f, desc))
587 			continue;
588 
589 		spin_lock_bh(&br->hash_lock);
590 		if (!hlist_unhashed(&f->fdb_node))
591 			fdb_delete(br, f, true);
592 		spin_unlock_bh(&br->hash_lock);
593 	}
594 	rcu_read_unlock();
595 }
596 
__ndm_state_to_fdb_flags(u16 ndm_state)597 static unsigned long __ndm_state_to_fdb_flags(u16 ndm_state)
598 {
599 	unsigned long flags = 0;
600 
601 	if (ndm_state & NUD_PERMANENT)
602 		__set_bit(BR_FDB_LOCAL, &flags);
603 	if (ndm_state & NUD_NOARP)
604 		__set_bit(BR_FDB_STATIC, &flags);
605 
606 	return flags;
607 }
608 
__ndm_flags_to_fdb_flags(u8 ndm_flags)609 static unsigned long __ndm_flags_to_fdb_flags(u8 ndm_flags)
610 {
611 	unsigned long flags = 0;
612 
613 	if (ndm_flags & NTF_USE)
614 		__set_bit(BR_FDB_ADDED_BY_USER, &flags);
615 	if (ndm_flags & NTF_EXT_LEARNED)
616 		__set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &flags);
617 	if (ndm_flags & NTF_OFFLOADED)
618 		__set_bit(BR_FDB_OFFLOADED, &flags);
619 	if (ndm_flags & NTF_STICKY)
620 		__set_bit(BR_FDB_STICKY, &flags);
621 
622 	return flags;
623 }
624 
__fdb_flush_validate_ifindex(const struct net_bridge * br,int ifindex,struct netlink_ext_ack * extack)625 static int __fdb_flush_validate_ifindex(const struct net_bridge *br,
626 					int ifindex,
627 					struct netlink_ext_ack *extack)
628 {
629 	const struct net_device *dev;
630 
631 	dev = __dev_get_by_index(dev_net(br->dev), ifindex);
632 	if (!dev) {
633 		NL_SET_ERR_MSG_MOD(extack, "Unknown flush device ifindex");
634 		return -ENODEV;
635 	}
636 	if (!netif_is_bridge_master(dev) && !netif_is_bridge_port(dev)) {
637 		NL_SET_ERR_MSG_MOD(extack, "Flush device is not a bridge or bridge port");
638 		return -EINVAL;
639 	}
640 	if (netif_is_bridge_master(dev) && dev != br->dev) {
641 		NL_SET_ERR_MSG_MOD(extack,
642 				   "Flush bridge device does not match target bridge device");
643 		return -EINVAL;
644 	}
645 	if (netif_is_bridge_port(dev)) {
646 		struct net_bridge_port *p = br_port_get_rtnl(dev);
647 
648 		if (p->br != br) {
649 			NL_SET_ERR_MSG_MOD(extack, "Port belongs to a different bridge device");
650 			return -EINVAL;
651 		}
652 	}
653 
654 	return 0;
655 }
656 
br_fdb_delete_bulk(struct ndmsg * ndm,struct nlattr * tb[],struct net_device * dev,u16 vid,struct netlink_ext_ack * extack)657 int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr *tb[],
658 		       struct net_device *dev, u16 vid,
659 		       struct netlink_ext_ack *extack)
660 {
661 	u8 ndm_flags = ndm->ndm_flags & ~FDB_FLUSH_IGNORED_NDM_FLAGS;
662 	struct net_bridge_fdb_flush_desc desc = { .vlan_id = vid };
663 	struct net_bridge_port *p = NULL;
664 	struct net_bridge *br;
665 
666 	if (netif_is_bridge_master(dev)) {
667 		br = netdev_priv(dev);
668 	} else {
669 		p = br_port_get_rtnl(dev);
670 		if (!p) {
671 			NL_SET_ERR_MSG_MOD(extack, "Device is not a bridge port");
672 			return -EINVAL;
673 		}
674 		br = p->br;
675 	}
676 
677 	if (ndm_flags & ~FDB_FLUSH_ALLOWED_NDM_FLAGS) {
678 		NL_SET_ERR_MSG(extack, "Unsupported fdb flush ndm flag bits set");
679 		return -EINVAL;
680 	}
681 	if (ndm->ndm_state & ~FDB_FLUSH_ALLOWED_NDM_STATES) {
682 		NL_SET_ERR_MSG(extack, "Unsupported fdb flush ndm state bits set");
683 		return -EINVAL;
684 	}
685 
686 	desc.flags |= __ndm_state_to_fdb_flags(ndm->ndm_state);
687 	desc.flags |= __ndm_flags_to_fdb_flags(ndm_flags);
688 	if (tb[NDA_NDM_STATE_MASK]) {
689 		u16 ndm_state_mask = nla_get_u16(tb[NDA_NDM_STATE_MASK]);
690 
691 		desc.flags_mask |= __ndm_state_to_fdb_flags(ndm_state_mask);
692 	}
693 	if (tb[NDA_NDM_FLAGS_MASK]) {
694 		u8 ndm_flags_mask = nla_get_u8(tb[NDA_NDM_FLAGS_MASK]);
695 
696 		desc.flags_mask |= __ndm_flags_to_fdb_flags(ndm_flags_mask);
697 	}
698 	if (tb[NDA_IFINDEX]) {
699 		int err, ifidx = nla_get_s32(tb[NDA_IFINDEX]);
700 
701 		err = __fdb_flush_validate_ifindex(br, ifidx, extack);
702 		if (err)
703 			return err;
704 		desc.port_ifindex = ifidx;
705 	} else if (p) {
706 		/* flush was invoked with port device and NTF_MASTER */
707 		desc.port_ifindex = p->dev->ifindex;
708 	}
709 
710 	br_debug(br, "flushing port ifindex: %d vlan id: %u flags: 0x%lx flags mask: 0x%lx\n",
711 		 desc.port_ifindex, desc.vlan_id, desc.flags, desc.flags_mask);
712 
713 	br_fdb_flush(br, &desc);
714 
715 	return 0;
716 }
717 
718 /* Flush all entries referring to a specific port.
719  * if do_all is set also flush static entries
720  * if vid is set delete all entries that match the vlan_id
721  */
br_fdb_delete_by_port(struct net_bridge * br,const struct net_bridge_port * p,u16 vid,int do_all)722 void br_fdb_delete_by_port(struct net_bridge *br,
723 			   const struct net_bridge_port *p,
724 			   u16 vid,
725 			   int do_all)
726 {
727 	struct net_bridge_fdb_entry *f;
728 	struct hlist_node *tmp;
729 
730 	spin_lock_bh(&br->hash_lock);
731 	hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
732 		if (f->dst != p)
733 			continue;
734 
735 		if (!do_all)
736 			if (test_bit(BR_FDB_STATIC, &f->flags) ||
737 			    (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags) &&
738 			     !test_bit(BR_FDB_OFFLOADED, &f->flags)) ||
739 			    (vid && f->key.vlan_id != vid))
740 				continue;
741 
742 		if (test_bit(BR_FDB_LOCAL, &f->flags))
743 			fdb_delete_local(br, p, f);
744 		else
745 			fdb_delete(br, f, true);
746 	}
747 	spin_unlock_bh(&br->hash_lock);
748 }
749 
750 #if IS_ENABLED(CONFIG_ATM_LANE)
751 /* Interface used by ATM LANE hook to test
752  * if an addr is on some other bridge port */
br_fdb_test_addr(struct net_device * dev,unsigned char * addr)753 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
754 {
755 	struct net_bridge_fdb_entry *fdb;
756 	struct net_bridge_port *port;
757 	int ret;
758 
759 	rcu_read_lock();
760 	port = br_port_get_rcu(dev);
761 	if (!port)
762 		ret = 0;
763 	else {
764 		const struct net_bridge_port *dst = NULL;
765 
766 		fdb = br_fdb_find_rcu(port->br, addr, 0);
767 		if (fdb)
768 			dst = READ_ONCE(fdb->dst);
769 
770 		ret = dst && dst->dev != dev &&
771 		      dst->state == BR_STATE_FORWARDING;
772 	}
773 	rcu_read_unlock();
774 
775 	return ret;
776 }
777 #endif /* CONFIG_ATM_LANE */
778 
779 /*
780  * Fill buffer with forwarding table records in
781  * the API format.
782  */
br_fdb_fillbuf(struct net_bridge * br,void * buf,unsigned long maxnum,unsigned long skip)783 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
784 		   unsigned long maxnum, unsigned long skip)
785 {
786 	struct net_bridge_fdb_entry *f;
787 	struct __fdb_entry *fe = buf;
788 	int num = 0;
789 
790 	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
791 
792 	rcu_read_lock();
793 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
794 		if (num >= maxnum)
795 			break;
796 
797 		if (has_expired(br, f))
798 			continue;
799 
800 		/* ignore pseudo entry for local MAC address */
801 		if (!f->dst)
802 			continue;
803 
804 		if (skip) {
805 			--skip;
806 			continue;
807 		}
808 
809 		/* convert from internal format to API */
810 		memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN);
811 
812 		/* due to ABI compat need to split into hi/lo */
813 		fe->port_no = f->dst->port_no;
814 		fe->port_hi = f->dst->port_no >> 8;
815 
816 		fe->is_local = test_bit(BR_FDB_LOCAL, &f->flags);
817 		if (!test_bit(BR_FDB_STATIC, &f->flags))
818 			fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
819 		++fe;
820 		++num;
821 	}
822 	rcu_read_unlock();
823 
824 	return num;
825 }
826 
827 /* Add entry for local address of interface */
br_fdb_add_local(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid)828 int br_fdb_add_local(struct net_bridge *br, struct net_bridge_port *source,
829 		     const unsigned char *addr, u16 vid)
830 {
831 	int ret;
832 
833 	spin_lock_bh(&br->hash_lock);
834 	ret = fdb_add_local(br, source, addr, vid);
835 	spin_unlock_bh(&br->hash_lock);
836 	return ret;
837 }
838 
839 /* returns true if the fdb was modified */
__fdb_mark_active(struct net_bridge_fdb_entry * fdb)840 static bool __fdb_mark_active(struct net_bridge_fdb_entry *fdb)
841 {
842 	return !!(test_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags) &&
843 		  test_and_clear_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags));
844 }
845 
br_fdb_update(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid,unsigned long flags)846 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
847 		   const unsigned char *addr, u16 vid, unsigned long flags)
848 {
849 	struct net_bridge_fdb_entry *fdb;
850 
851 	/* some users want to always flood. */
852 	if (hold_time(br) == 0)
853 		return;
854 
855 	fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
856 	if (likely(fdb)) {
857 		/* attempt to update an entry for a local interface */
858 		if (unlikely(test_bit(BR_FDB_LOCAL, &fdb->flags))) {
859 			if (net_ratelimit())
860 				br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
861 					source->dev->name, addr, vid);
862 		} else {
863 			unsigned long now = jiffies;
864 			bool fdb_modified = false;
865 
866 			if (now != fdb->updated) {
867 				fdb->updated = now;
868 				fdb_modified = __fdb_mark_active(fdb);
869 			}
870 
871 			/* fastpath: update of existing entry */
872 			if (unlikely(source != READ_ONCE(fdb->dst) &&
873 				     !test_bit(BR_FDB_STICKY, &fdb->flags))) {
874 				br_switchdev_fdb_notify(br, fdb, RTM_DELNEIGH);
875 				WRITE_ONCE(fdb->dst, source);
876 				fdb_modified = true;
877 				/* Take over HW learned entry */
878 				if (unlikely(test_bit(BR_FDB_ADDED_BY_EXT_LEARN,
879 						      &fdb->flags)))
880 					clear_bit(BR_FDB_ADDED_BY_EXT_LEARN,
881 						  &fdb->flags);
882 			}
883 
884 			if (unlikely(test_bit(BR_FDB_ADDED_BY_USER, &flags)))
885 				set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
886 			if (unlikely(fdb_modified)) {
887 				trace_br_fdb_update(br, source, addr, vid, flags);
888 				fdb_notify(br, fdb, RTM_NEWNEIGH, true);
889 			}
890 		}
891 	} else {
892 		spin_lock(&br->hash_lock);
893 		fdb = fdb_create(br, source, addr, vid, flags);
894 		if (fdb) {
895 			trace_br_fdb_update(br, source, addr, vid, flags);
896 			fdb_notify(br, fdb, RTM_NEWNEIGH, true);
897 		}
898 		/* else  we lose race and someone else inserts
899 		 * it first, don't bother updating
900 		 */
901 		spin_unlock(&br->hash_lock);
902 	}
903 }
904 
905 /* 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)906 int br_fdb_dump(struct sk_buff *skb,
907 		struct netlink_callback *cb,
908 		struct net_device *dev,
909 		struct net_device *filter_dev,
910 		int *idx)
911 {
912 	struct net_bridge *br = netdev_priv(dev);
913 	struct net_bridge_fdb_entry *f;
914 	int err = 0;
915 
916 	if (!netif_is_bridge_master(dev))
917 		return err;
918 
919 	if (!filter_dev) {
920 		err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
921 		if (err < 0)
922 			return err;
923 	}
924 
925 	rcu_read_lock();
926 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
927 		if (*idx < cb->args[2])
928 			goto skip;
929 		if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
930 			if (filter_dev != dev)
931 				goto skip;
932 			/* !f->dst is a special case for bridge
933 			 * It means the MAC belongs to the bridge
934 			 * Therefore need a little more filtering
935 			 * we only want to dump the !f->dst case
936 			 */
937 			if (f->dst)
938 				goto skip;
939 		}
940 		if (!filter_dev && f->dst)
941 			goto skip;
942 
943 		err = fdb_fill_info(skb, br, f,
944 				    NETLINK_CB(cb->skb).portid,
945 				    cb->nlh->nlmsg_seq,
946 				    RTM_NEWNEIGH,
947 				    NLM_F_MULTI);
948 		if (err < 0)
949 			break;
950 skip:
951 		*idx += 1;
952 	}
953 	rcu_read_unlock();
954 
955 	return err;
956 }
957 
br_fdb_get(struct sk_buff * skb,struct nlattr * tb[],struct net_device * dev,const unsigned char * addr,u16 vid,u32 portid,u32 seq,struct netlink_ext_ack * extack)958 int br_fdb_get(struct sk_buff *skb,
959 	       struct nlattr *tb[],
960 	       struct net_device *dev,
961 	       const unsigned char *addr,
962 	       u16 vid, u32 portid, u32 seq,
963 	       struct netlink_ext_ack *extack)
964 {
965 	struct net_bridge *br = netdev_priv(dev);
966 	struct net_bridge_fdb_entry *f;
967 	int err = 0;
968 
969 	rcu_read_lock();
970 	f = br_fdb_find_rcu(br, addr, vid);
971 	if (!f) {
972 		NL_SET_ERR_MSG(extack, "Fdb entry not found");
973 		err = -ENOENT;
974 		goto errout;
975 	}
976 
977 	err = fdb_fill_info(skb, br, f, portid, seq,
978 			    RTM_NEWNEIGH, 0);
979 errout:
980 	rcu_read_unlock();
981 	return err;
982 }
983 
984 /* returns true if the fdb is modified */
fdb_handle_notify(struct net_bridge_fdb_entry * fdb,u8 notify)985 static bool fdb_handle_notify(struct net_bridge_fdb_entry *fdb, u8 notify)
986 {
987 	bool modified = false;
988 
989 	/* allow to mark an entry as inactive, usually done on creation */
990 	if ((notify & FDB_NOTIFY_INACTIVE_BIT) &&
991 	    !test_and_set_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags))
992 		modified = true;
993 
994 	if ((notify & FDB_NOTIFY_BIT) &&
995 	    !test_and_set_bit(BR_FDB_NOTIFY, &fdb->flags)) {
996 		/* enabled activity tracking */
997 		modified = true;
998 	} else if (!(notify & FDB_NOTIFY_BIT) &&
999 		   test_and_clear_bit(BR_FDB_NOTIFY, &fdb->flags)) {
1000 		/* disabled activity tracking, clear notify state */
1001 		clear_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags);
1002 		modified = true;
1003 	}
1004 
1005 	return modified;
1006 }
1007 
1008 /* Update (create or replace) forwarding database entry */
fdb_add_entry(struct net_bridge * br,struct net_bridge_port * source,const u8 * addr,struct ndmsg * ndm,u16 flags,u16 vid,struct nlattr * nfea_tb[])1009 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
1010 			 const u8 *addr, struct ndmsg *ndm, u16 flags, u16 vid,
1011 			 struct nlattr *nfea_tb[])
1012 {
1013 	bool is_sticky = !!(ndm->ndm_flags & NTF_STICKY);
1014 	bool refresh = !nfea_tb[NFEA_DONT_REFRESH];
1015 	struct net_bridge_fdb_entry *fdb;
1016 	u16 state = ndm->ndm_state;
1017 	bool modified = false;
1018 	u8 notify = 0;
1019 
1020 	/* If the port cannot learn allow only local and static entries */
1021 	if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
1022 	    !(source->state == BR_STATE_LEARNING ||
1023 	      source->state == BR_STATE_FORWARDING))
1024 		return -EPERM;
1025 
1026 	if (!source && !(state & NUD_PERMANENT)) {
1027 		pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
1028 			br->dev->name);
1029 		return -EINVAL;
1030 	}
1031 
1032 	if (is_sticky && (state & NUD_PERMANENT))
1033 		return -EINVAL;
1034 
1035 	if (nfea_tb[NFEA_ACTIVITY_NOTIFY]) {
1036 		notify = nla_get_u8(nfea_tb[NFEA_ACTIVITY_NOTIFY]);
1037 		if ((notify & ~BR_FDB_NOTIFY_SETTABLE_BITS) ||
1038 		    (notify & BR_FDB_NOTIFY_SETTABLE_BITS) == FDB_NOTIFY_INACTIVE_BIT)
1039 			return -EINVAL;
1040 	}
1041 
1042 	fdb = br_fdb_find(br, addr, vid);
1043 	if (fdb == NULL) {
1044 		if (!(flags & NLM_F_CREATE))
1045 			return -ENOENT;
1046 
1047 		fdb = fdb_create(br, source, addr, vid, 0);
1048 		if (!fdb)
1049 			return -ENOMEM;
1050 
1051 		modified = true;
1052 	} else {
1053 		if (flags & NLM_F_EXCL)
1054 			return -EEXIST;
1055 
1056 		if (READ_ONCE(fdb->dst) != source) {
1057 			WRITE_ONCE(fdb->dst, source);
1058 			modified = true;
1059 		}
1060 	}
1061 
1062 	if (fdb_to_nud(br, fdb) != state) {
1063 		if (state & NUD_PERMANENT) {
1064 			set_bit(BR_FDB_LOCAL, &fdb->flags);
1065 			if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
1066 				fdb_add_hw_addr(br, addr);
1067 		} else if (state & NUD_NOARP) {
1068 			clear_bit(BR_FDB_LOCAL, &fdb->flags);
1069 			if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
1070 				fdb_add_hw_addr(br, addr);
1071 		} else {
1072 			clear_bit(BR_FDB_LOCAL, &fdb->flags);
1073 			if (test_and_clear_bit(BR_FDB_STATIC, &fdb->flags))
1074 				fdb_del_hw_addr(br, addr);
1075 		}
1076 
1077 		modified = true;
1078 	}
1079 
1080 	if (is_sticky != test_bit(BR_FDB_STICKY, &fdb->flags)) {
1081 		change_bit(BR_FDB_STICKY, &fdb->flags);
1082 		modified = true;
1083 	}
1084 
1085 	if (fdb_handle_notify(fdb, notify))
1086 		modified = true;
1087 
1088 	set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
1089 
1090 	fdb->used = jiffies;
1091 	if (modified) {
1092 		if (refresh)
1093 			fdb->updated = jiffies;
1094 		fdb_notify(br, fdb, RTM_NEWNEIGH, true);
1095 	}
1096 
1097 	return 0;
1098 }
1099 
__br_fdb_add(struct ndmsg * ndm,struct net_bridge * br,struct net_bridge_port * p,const unsigned char * addr,u16 nlh_flags,u16 vid,struct nlattr * nfea_tb[],struct netlink_ext_ack * extack)1100 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
1101 			struct net_bridge_port *p, const unsigned char *addr,
1102 			u16 nlh_flags, u16 vid, struct nlattr *nfea_tb[],
1103 			struct netlink_ext_ack *extack)
1104 {
1105 	int err = 0;
1106 
1107 	if (ndm->ndm_flags & NTF_USE) {
1108 		if (!p) {
1109 			pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
1110 				br->dev->name);
1111 			return -EINVAL;
1112 		}
1113 		if (!nbp_state_should_learn(p))
1114 			return 0;
1115 
1116 		local_bh_disable();
1117 		rcu_read_lock();
1118 		br_fdb_update(br, p, addr, vid, BIT(BR_FDB_ADDED_BY_USER));
1119 		rcu_read_unlock();
1120 		local_bh_enable();
1121 	} else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
1122 		if (!p && !(ndm->ndm_state & NUD_PERMANENT)) {
1123 			NL_SET_ERR_MSG_MOD(extack,
1124 					   "FDB entry towards bridge must be permanent");
1125 			return -EINVAL;
1126 		}
1127 		err = br_fdb_external_learn_add(br, p, addr, vid, true);
1128 	} else {
1129 		spin_lock_bh(&br->hash_lock);
1130 		err = fdb_add_entry(br, p, addr, ndm, nlh_flags, vid, nfea_tb);
1131 		spin_unlock_bh(&br->hash_lock);
1132 	}
1133 
1134 	return err;
1135 }
1136 
1137 static const struct nla_policy br_nda_fdb_pol[NFEA_MAX + 1] = {
1138 	[NFEA_ACTIVITY_NOTIFY]	= { .type = NLA_U8 },
1139 	[NFEA_DONT_REFRESH]	= { .type = NLA_FLAG },
1140 };
1141 
1142 /* 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,struct netlink_ext_ack * extack)1143 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
1144 	       struct net_device *dev,
1145 	       const unsigned char *addr, u16 vid, u16 nlh_flags,
1146 	       struct netlink_ext_ack *extack)
1147 {
1148 	struct nlattr *nfea_tb[NFEA_MAX + 1], *attr;
1149 	struct net_bridge_vlan_group *vg;
1150 	struct net_bridge_port *p = NULL;
1151 	struct net_bridge_vlan *v;
1152 	struct net_bridge *br = NULL;
1153 	int err = 0;
1154 
1155 	trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);
1156 
1157 	if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
1158 		pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
1159 		return -EINVAL;
1160 	}
1161 
1162 	if (is_zero_ether_addr(addr)) {
1163 		pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
1164 		return -EINVAL;
1165 	}
1166 
1167 	if (netif_is_bridge_master(dev)) {
1168 		br = netdev_priv(dev);
1169 		vg = br_vlan_group(br);
1170 	} else {
1171 		p = br_port_get_rtnl(dev);
1172 		if (!p) {
1173 			pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
1174 				dev->name);
1175 			return -EINVAL;
1176 		}
1177 		br = p->br;
1178 		vg = nbp_vlan_group(p);
1179 	}
1180 
1181 	if (tb[NDA_FDB_EXT_ATTRS]) {
1182 		attr = tb[NDA_FDB_EXT_ATTRS];
1183 		err = nla_parse_nested(nfea_tb, NFEA_MAX, attr,
1184 				       br_nda_fdb_pol, extack);
1185 		if (err)
1186 			return err;
1187 	} else {
1188 		memset(nfea_tb, 0, sizeof(struct nlattr *) * (NFEA_MAX + 1));
1189 	}
1190 
1191 	if (vid) {
1192 		v = br_vlan_find(vg, vid);
1193 		if (!v || !br_vlan_should_use(v)) {
1194 			pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1195 			return -EINVAL;
1196 		}
1197 
1198 		/* VID was specified, so use it. */
1199 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid, nfea_tb,
1200 				   extack);
1201 	} else {
1202 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0, nfea_tb,
1203 				   extack);
1204 		if (err || !vg || !vg->num_vlans)
1205 			goto out;
1206 
1207 		/* We have vlans configured on this port and user didn't
1208 		 * specify a VLAN.  To be nice, add/update entry for every
1209 		 * vlan on this port.
1210 		 */
1211 		list_for_each_entry(v, &vg->vlan_list, vlist) {
1212 			if (!br_vlan_should_use(v))
1213 				continue;
1214 			err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid,
1215 					   nfea_tb, extack);
1216 			if (err)
1217 				goto out;
1218 		}
1219 	}
1220 
1221 out:
1222 	return err;
1223 }
1224 
fdb_delete_by_addr_and_port(struct net_bridge * br,const struct net_bridge_port * p,const u8 * addr,u16 vlan)1225 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
1226 				       const struct net_bridge_port *p,
1227 				       const u8 *addr, u16 vlan)
1228 {
1229 	struct net_bridge_fdb_entry *fdb;
1230 
1231 	fdb = br_fdb_find(br, addr, vlan);
1232 	if (!fdb || READ_ONCE(fdb->dst) != p)
1233 		return -ENOENT;
1234 
1235 	fdb_delete(br, fdb, true);
1236 
1237 	return 0;
1238 }
1239 
__br_fdb_delete(struct net_bridge * br,const struct net_bridge_port * p,const unsigned char * addr,u16 vid)1240 static int __br_fdb_delete(struct net_bridge *br,
1241 			   const struct net_bridge_port *p,
1242 			   const unsigned char *addr, u16 vid)
1243 {
1244 	int err;
1245 
1246 	spin_lock_bh(&br->hash_lock);
1247 	err = fdb_delete_by_addr_and_port(br, p, addr, vid);
1248 	spin_unlock_bh(&br->hash_lock);
1249 
1250 	return err;
1251 }
1252 
1253 /* 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,struct netlink_ext_ack * extack)1254 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
1255 		  struct net_device *dev,
1256 		  const unsigned char *addr, u16 vid,
1257 		  struct netlink_ext_ack *extack)
1258 {
1259 	struct net_bridge_vlan_group *vg;
1260 	struct net_bridge_port *p = NULL;
1261 	struct net_bridge_vlan *v;
1262 	struct net_bridge *br;
1263 	int err;
1264 
1265 	if (netif_is_bridge_master(dev)) {
1266 		br = netdev_priv(dev);
1267 		vg = br_vlan_group(br);
1268 	} else {
1269 		p = br_port_get_rtnl(dev);
1270 		if (!p) {
1271 			pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1272 				dev->name);
1273 			return -EINVAL;
1274 		}
1275 		vg = nbp_vlan_group(p);
1276 		br = p->br;
1277 	}
1278 
1279 	if (vid) {
1280 		v = br_vlan_find(vg, vid);
1281 		if (!v) {
1282 			pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1283 			return -EINVAL;
1284 		}
1285 
1286 		err = __br_fdb_delete(br, p, addr, vid);
1287 	} else {
1288 		err = -ENOENT;
1289 		err &= __br_fdb_delete(br, p, addr, 0);
1290 		if (!vg || !vg->num_vlans)
1291 			return err;
1292 
1293 		list_for_each_entry(v, &vg->vlan_list, vlist) {
1294 			if (!br_vlan_should_use(v))
1295 				continue;
1296 			err &= __br_fdb_delete(br, p, addr, v->vid);
1297 		}
1298 	}
1299 
1300 	return err;
1301 }
1302 
br_fdb_sync_static(struct net_bridge * br,struct net_bridge_port * p)1303 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1304 {
1305 	struct net_bridge_fdb_entry *f, *tmp;
1306 	int err = 0;
1307 
1308 	ASSERT_RTNL();
1309 
1310 	/* the key here is that static entries change only under rtnl */
1311 	rcu_read_lock();
1312 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1313 		/* We only care for static entries */
1314 		if (!test_bit(BR_FDB_STATIC, &f->flags))
1315 			continue;
1316 		err = dev_uc_add(p->dev, f->key.addr.addr);
1317 		if (err)
1318 			goto rollback;
1319 	}
1320 done:
1321 	rcu_read_unlock();
1322 
1323 	return err;
1324 
1325 rollback:
1326 	hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) {
1327 		/* We only care for static entries */
1328 		if (!test_bit(BR_FDB_STATIC, &tmp->flags))
1329 			continue;
1330 		if (tmp == f)
1331 			break;
1332 		dev_uc_del(p->dev, tmp->key.addr.addr);
1333 	}
1334 
1335 	goto done;
1336 }
1337 
br_fdb_unsync_static(struct net_bridge * br,struct net_bridge_port * p)1338 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1339 {
1340 	struct net_bridge_fdb_entry *f;
1341 
1342 	ASSERT_RTNL();
1343 
1344 	rcu_read_lock();
1345 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1346 		/* We only care for static entries */
1347 		if (!test_bit(BR_FDB_STATIC, &f->flags))
1348 			continue;
1349 
1350 		dev_uc_del(p->dev, f->key.addr.addr);
1351 	}
1352 	rcu_read_unlock();
1353 }
1354 
br_fdb_external_learn_add(struct net_bridge * br,struct net_bridge_port * p,const unsigned char * addr,u16 vid,bool swdev_notify)1355 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1356 			      const unsigned char *addr, u16 vid,
1357 			      bool swdev_notify)
1358 {
1359 	struct net_bridge_fdb_entry *fdb;
1360 	bool modified = false;
1361 	int err = 0;
1362 
1363 	trace_br_fdb_external_learn_add(br, p, addr, vid);
1364 
1365 	spin_lock_bh(&br->hash_lock);
1366 
1367 	fdb = br_fdb_find(br, addr, vid);
1368 	if (!fdb) {
1369 		unsigned long flags = BIT(BR_FDB_ADDED_BY_EXT_LEARN);
1370 
1371 		if (swdev_notify)
1372 			flags |= BIT(BR_FDB_ADDED_BY_USER);
1373 
1374 		if (!p)
1375 			flags |= BIT(BR_FDB_LOCAL);
1376 
1377 		fdb = fdb_create(br, p, addr, vid, flags);
1378 		if (!fdb) {
1379 			err = -ENOMEM;
1380 			goto err_unlock;
1381 		}
1382 		fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1383 	} else {
1384 		fdb->updated = jiffies;
1385 
1386 		if (READ_ONCE(fdb->dst) != p) {
1387 			WRITE_ONCE(fdb->dst, p);
1388 			modified = true;
1389 		}
1390 
1391 		if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) {
1392 			/* Refresh entry */
1393 			fdb->used = jiffies;
1394 		} else if (!test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags)) {
1395 			/* Take over SW learned entry */
1396 			set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags);
1397 			modified = true;
1398 		}
1399 
1400 		if (swdev_notify)
1401 			set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
1402 
1403 		if (!p)
1404 			set_bit(BR_FDB_LOCAL, &fdb->flags);
1405 
1406 		if (modified)
1407 			fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1408 	}
1409 
1410 err_unlock:
1411 	spin_unlock_bh(&br->hash_lock);
1412 
1413 	return err;
1414 }
1415 
br_fdb_external_learn_del(struct net_bridge * br,struct net_bridge_port * p,const unsigned char * addr,u16 vid,bool swdev_notify)1416 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1417 			      const unsigned char *addr, u16 vid,
1418 			      bool swdev_notify)
1419 {
1420 	struct net_bridge_fdb_entry *fdb;
1421 	int err = 0;
1422 
1423 	spin_lock_bh(&br->hash_lock);
1424 
1425 	fdb = br_fdb_find(br, addr, vid);
1426 	if (fdb && test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
1427 		fdb_delete(br, fdb, swdev_notify);
1428 	else
1429 		err = -ENOENT;
1430 
1431 	spin_unlock_bh(&br->hash_lock);
1432 
1433 	return err;
1434 }
1435 
br_fdb_offloaded_set(struct net_bridge * br,struct net_bridge_port * p,const unsigned char * addr,u16 vid,bool offloaded)1436 void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1437 			  const unsigned char *addr, u16 vid, bool offloaded)
1438 {
1439 	struct net_bridge_fdb_entry *fdb;
1440 
1441 	spin_lock_bh(&br->hash_lock);
1442 
1443 	fdb = br_fdb_find(br, addr, vid);
1444 	if (fdb && offloaded != test_bit(BR_FDB_OFFLOADED, &fdb->flags))
1445 		change_bit(BR_FDB_OFFLOADED, &fdb->flags);
1446 
1447 	spin_unlock_bh(&br->hash_lock);
1448 }
1449 
br_fdb_clear_offload(const struct net_device * dev,u16 vid)1450 void br_fdb_clear_offload(const struct net_device *dev, u16 vid)
1451 {
1452 	struct net_bridge_fdb_entry *f;
1453 	struct net_bridge_port *p;
1454 
1455 	ASSERT_RTNL();
1456 
1457 	p = br_port_get_rtnl(dev);
1458 	if (!p)
1459 		return;
1460 
1461 	spin_lock_bh(&p->br->hash_lock);
1462 	hlist_for_each_entry(f, &p->br->fdb_list, fdb_node) {
1463 		if (f->dst == p && f->key.vlan_id == vid)
1464 			clear_bit(BR_FDB_OFFLOADED, &f->flags);
1465 	}
1466 	spin_unlock_bh(&p->br->hash_lock);
1467 }
1468 EXPORT_SYMBOL_GPL(br_fdb_clear_offload);
1469