xref: /openbmc/linux/net/bridge/br_fdb.c (revision c6c535a4)
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 	u32 ext_flags = 0;
109 
110 	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
111 	if (nlh == NULL)
112 		return -EMSGSIZE;
113 
114 	ndm = nlmsg_data(nlh);
115 	ndm->ndm_family	 = AF_BRIDGE;
116 	ndm->ndm_pad1    = 0;
117 	ndm->ndm_pad2    = 0;
118 	ndm->ndm_flags	 = 0;
119 	ndm->ndm_type	 = 0;
120 	ndm->ndm_ifindex = dst ? dst->dev->ifindex : br->dev->ifindex;
121 	ndm->ndm_state   = fdb_to_nud(br, fdb);
122 
123 	if (test_bit(BR_FDB_OFFLOADED, &fdb->flags))
124 		ndm->ndm_flags |= NTF_OFFLOADED;
125 	if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
126 		ndm->ndm_flags |= NTF_EXT_LEARNED;
127 	if (test_bit(BR_FDB_STICKY, &fdb->flags))
128 		ndm->ndm_flags |= NTF_STICKY;
129 	if (test_bit(BR_FDB_LOCKED, &fdb->flags))
130 		ext_flags |= NTF_EXT_LOCKED;
131 
132 	if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr))
133 		goto nla_put_failure;
134 	if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
135 		goto nla_put_failure;
136 	if (nla_put_u32(skb, NDA_FLAGS_EXT, ext_flags))
137 		goto nla_put_failure;
138 
139 	ci.ndm_used	 = jiffies_to_clock_t(now - fdb->used);
140 	ci.ndm_confirmed = 0;
141 	ci.ndm_updated	 = jiffies_to_clock_t(now - fdb->updated);
142 	ci.ndm_refcnt	 = 0;
143 	if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
144 		goto nla_put_failure;
145 
146 	if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16),
147 					&fdb->key.vlan_id))
148 		goto nla_put_failure;
149 
150 	if (test_bit(BR_FDB_NOTIFY, &fdb->flags)) {
151 		struct nlattr *nest = nla_nest_start(skb, NDA_FDB_EXT_ATTRS);
152 		u8 notify_bits = FDB_NOTIFY_BIT;
153 
154 		if (!nest)
155 			goto nla_put_failure;
156 		if (test_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags))
157 			notify_bits |= FDB_NOTIFY_INACTIVE_BIT;
158 
159 		if (nla_put_u8(skb, NFEA_ACTIVITY_NOTIFY, notify_bits)) {
160 			nla_nest_cancel(skb, nest);
161 			goto nla_put_failure;
162 		}
163 
164 		nla_nest_end(skb, nest);
165 	}
166 
167 	nlmsg_end(skb, nlh);
168 	return 0;
169 
170 nla_put_failure:
171 	nlmsg_cancel(skb, nlh);
172 	return -EMSGSIZE;
173 }
174 
fdb_nlmsg_size(void)175 static inline size_t fdb_nlmsg_size(void)
176 {
177 	return NLMSG_ALIGN(sizeof(struct ndmsg))
178 		+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
179 		+ nla_total_size(sizeof(u32)) /* NDA_MASTER */
180 		+ nla_total_size(sizeof(u32)) /* NDA_FLAGS_EXT */
181 		+ nla_total_size(sizeof(u16)) /* NDA_VLAN */
182 		+ nla_total_size(sizeof(struct nda_cacheinfo))
183 		+ nla_total_size(0) /* NDA_FDB_EXT_ATTRS */
184 		+ nla_total_size(sizeof(u8)); /* NFEA_ACTIVITY_NOTIFY */
185 }
186 
fdb_notify(struct net_bridge * br,const struct net_bridge_fdb_entry * fdb,int type,bool swdev_notify)187 static void fdb_notify(struct net_bridge *br,
188 		       const struct net_bridge_fdb_entry *fdb, int type,
189 		       bool swdev_notify)
190 {
191 	struct net *net = dev_net(br->dev);
192 	struct sk_buff *skb;
193 	int err = -ENOBUFS;
194 
195 	if (swdev_notify)
196 		br_switchdev_fdb_notify(br, fdb, type);
197 
198 	skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
199 	if (skb == NULL)
200 		goto errout;
201 
202 	err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
203 	if (err < 0) {
204 		/* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
205 		WARN_ON(err == -EMSGSIZE);
206 		kfree_skb(skb);
207 		goto errout;
208 	}
209 	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
210 	return;
211 errout:
212 	rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
213 }
214 
fdb_find_rcu(struct rhashtable * tbl,const unsigned char * addr,__u16 vid)215 static struct net_bridge_fdb_entry *fdb_find_rcu(struct rhashtable *tbl,
216 						 const unsigned char *addr,
217 						 __u16 vid)
218 {
219 	struct net_bridge_fdb_key key;
220 
221 	WARN_ON_ONCE(!rcu_read_lock_held());
222 
223 	key.vlan_id = vid;
224 	memcpy(key.addr.addr, addr, sizeof(key.addr.addr));
225 
226 	return rhashtable_lookup(tbl, &key, br_fdb_rht_params);
227 }
228 
229 /* requires bridge hash_lock */
br_fdb_find(struct net_bridge * br,const unsigned char * addr,__u16 vid)230 static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
231 						const unsigned char *addr,
232 						__u16 vid)
233 {
234 	struct net_bridge_fdb_entry *fdb;
235 
236 	lockdep_assert_held_once(&br->hash_lock);
237 
238 	rcu_read_lock();
239 	fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
240 	rcu_read_unlock();
241 
242 	return fdb;
243 }
244 
br_fdb_find_port(const struct net_device * br_dev,const unsigned char * addr,__u16 vid)245 struct net_device *br_fdb_find_port(const struct net_device *br_dev,
246 				    const unsigned char *addr,
247 				    __u16 vid)
248 {
249 	struct net_bridge_fdb_entry *f;
250 	struct net_device *dev = NULL;
251 	struct net_bridge *br;
252 
253 	ASSERT_RTNL();
254 
255 	if (!netif_is_bridge_master(br_dev))
256 		return NULL;
257 
258 	br = netdev_priv(br_dev);
259 	rcu_read_lock();
260 	f = br_fdb_find_rcu(br, addr, vid);
261 	if (f && f->dst)
262 		dev = f->dst->dev;
263 	rcu_read_unlock();
264 
265 	return dev;
266 }
267 EXPORT_SYMBOL_GPL(br_fdb_find_port);
268 
br_fdb_find_rcu(struct net_bridge * br,const unsigned char * addr,__u16 vid)269 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
270 					     const unsigned char *addr,
271 					     __u16 vid)
272 {
273 	return fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
274 }
275 
276 /* When a static FDB entry is added, the mac address from the entry is
277  * added to the bridge private HW address list and all required ports
278  * are then updated with the new information.
279  * Called under RTNL.
280  */
fdb_add_hw_addr(struct net_bridge * br,const unsigned char * addr)281 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
282 {
283 	int err;
284 	struct net_bridge_port *p;
285 
286 	ASSERT_RTNL();
287 
288 	list_for_each_entry(p, &br->port_list, list) {
289 		if (!br_promisc_port(p)) {
290 			err = dev_uc_add(p->dev, addr);
291 			if (err)
292 				goto undo;
293 		}
294 	}
295 
296 	return;
297 undo:
298 	list_for_each_entry_continue_reverse(p, &br->port_list, list) {
299 		if (!br_promisc_port(p))
300 			dev_uc_del(p->dev, addr);
301 	}
302 }
303 
304 /* When a static FDB entry is deleted, the HW address from that entry is
305  * also removed from the bridge private HW address list and updates all
306  * the ports with needed information.
307  * Called under RTNL.
308  */
fdb_del_hw_addr(struct net_bridge * br,const unsigned char * addr)309 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
310 {
311 	struct net_bridge_port *p;
312 
313 	ASSERT_RTNL();
314 
315 	list_for_each_entry(p, &br->port_list, list) {
316 		if (!br_promisc_port(p))
317 			dev_uc_del(p->dev, addr);
318 	}
319 }
320 
fdb_delete(struct net_bridge * br,struct net_bridge_fdb_entry * f,bool swdev_notify)321 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f,
322 		       bool swdev_notify)
323 {
324 	trace_fdb_delete(br, f);
325 
326 	if (test_bit(BR_FDB_STATIC, &f->flags))
327 		fdb_del_hw_addr(br, f->key.addr.addr);
328 
329 	hlist_del_init_rcu(&f->fdb_node);
330 	rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode,
331 			       br_fdb_rht_params);
332 	fdb_notify(br, f, RTM_DELNEIGH, swdev_notify);
333 	call_rcu(&f->rcu, fdb_rcu_free);
334 }
335 
336 /* 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)337 static void fdb_delete_local(struct net_bridge *br,
338 			     const struct net_bridge_port *p,
339 			     struct net_bridge_fdb_entry *f)
340 {
341 	const unsigned char *addr = f->key.addr.addr;
342 	struct net_bridge_vlan_group *vg;
343 	const struct net_bridge_vlan *v;
344 	struct net_bridge_port *op;
345 	u16 vid = f->key.vlan_id;
346 
347 	/* Maybe another port has same hw addr? */
348 	list_for_each_entry(op, &br->port_list, list) {
349 		vg = nbp_vlan_group(op);
350 		if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
351 		    (!vid || br_vlan_find(vg, vid))) {
352 			f->dst = op;
353 			clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
354 			return;
355 		}
356 	}
357 
358 	vg = br_vlan_group(br);
359 	v = br_vlan_find(vg, vid);
360 	/* Maybe bridge device has same hw addr? */
361 	if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
362 	    (!vid || (v && br_vlan_should_use(v)))) {
363 		f->dst = NULL;
364 		clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
365 		return;
366 	}
367 
368 	fdb_delete(br, f, true);
369 }
370 
br_fdb_find_delete_local(struct net_bridge * br,const struct net_bridge_port * p,const unsigned char * addr,u16 vid)371 void br_fdb_find_delete_local(struct net_bridge *br,
372 			      const struct net_bridge_port *p,
373 			      const unsigned char *addr, u16 vid)
374 {
375 	struct net_bridge_fdb_entry *f;
376 
377 	spin_lock_bh(&br->hash_lock);
378 	f = br_fdb_find(br, addr, vid);
379 	if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
380 	    !test_bit(BR_FDB_ADDED_BY_USER, &f->flags) && f->dst == p)
381 		fdb_delete_local(br, p, f);
382 	spin_unlock_bh(&br->hash_lock);
383 }
384 
fdb_create(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,__u16 vid,unsigned long flags)385 static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br,
386 					       struct net_bridge_port *source,
387 					       const unsigned char *addr,
388 					       __u16 vid,
389 					       unsigned long flags)
390 {
391 	struct net_bridge_fdb_entry *fdb;
392 	int err;
393 
394 	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
395 	if (!fdb)
396 		return NULL;
397 
398 	memcpy(fdb->key.addr.addr, addr, ETH_ALEN);
399 	WRITE_ONCE(fdb->dst, source);
400 	fdb->key.vlan_id = vid;
401 	fdb->flags = flags;
402 	fdb->updated = fdb->used = jiffies;
403 	err = rhashtable_lookup_insert_fast(&br->fdb_hash_tbl, &fdb->rhnode,
404 					    br_fdb_rht_params);
405 	if (err) {
406 		kmem_cache_free(br_fdb_cache, fdb);
407 		return NULL;
408 	}
409 
410 	hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list);
411 
412 	return fdb;
413 }
414 
fdb_add_local(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid)415 static int fdb_add_local(struct net_bridge *br, struct net_bridge_port *source,
416 			 const unsigned char *addr, u16 vid)
417 {
418 	struct net_bridge_fdb_entry *fdb;
419 
420 	if (!is_valid_ether_addr(addr))
421 		return -EINVAL;
422 
423 	fdb = br_fdb_find(br, addr, vid);
424 	if (fdb) {
425 		/* it is okay to have multiple ports with same
426 		 * address, just use the first one.
427 		 */
428 		if (test_bit(BR_FDB_LOCAL, &fdb->flags))
429 			return 0;
430 		br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
431 			source ? source->dev->name : br->dev->name, addr, vid);
432 		fdb_delete(br, fdb, true);
433 	}
434 
435 	fdb = fdb_create(br, source, addr, vid,
436 			 BIT(BR_FDB_LOCAL) | BIT(BR_FDB_STATIC));
437 	if (!fdb)
438 		return -ENOMEM;
439 
440 	fdb_add_hw_addr(br, addr);
441 	fdb_notify(br, fdb, RTM_NEWNEIGH, true);
442 	return 0;
443 }
444 
br_fdb_changeaddr(struct net_bridge_port * p,const unsigned char * newaddr)445 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
446 {
447 	struct net_bridge_vlan_group *vg;
448 	struct net_bridge_fdb_entry *f;
449 	struct net_bridge *br = p->br;
450 	struct net_bridge_vlan *v;
451 
452 	spin_lock_bh(&br->hash_lock);
453 	vg = nbp_vlan_group(p);
454 	hlist_for_each_entry(f, &br->fdb_list, fdb_node) {
455 		if (f->dst == p && test_bit(BR_FDB_LOCAL, &f->flags) &&
456 		    !test_bit(BR_FDB_ADDED_BY_USER, &f->flags)) {
457 			/* delete old one */
458 			fdb_delete_local(br, p, f);
459 
460 			/* if this port has no vlan information
461 			 * configured, we can safely be done at
462 			 * this point.
463 			 */
464 			if (!vg || !vg->num_vlans)
465 				goto insert;
466 		}
467 	}
468 
469 insert:
470 	/* insert new address,  may fail if invalid address or dup. */
471 	fdb_add_local(br, p, newaddr, 0);
472 
473 	if (!vg || !vg->num_vlans)
474 		goto done;
475 
476 	/* Now add entries for every VLAN configured on the port.
477 	 * This function runs under RTNL so the bitmap will not change
478 	 * from under us.
479 	 */
480 	list_for_each_entry(v, &vg->vlan_list, vlist)
481 		fdb_add_local(br, p, newaddr, v->vid);
482 
483 done:
484 	spin_unlock_bh(&br->hash_lock);
485 }
486 
br_fdb_change_mac_address(struct net_bridge * br,const u8 * newaddr)487 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
488 {
489 	struct net_bridge_vlan_group *vg;
490 	struct net_bridge_fdb_entry *f;
491 	struct net_bridge_vlan *v;
492 
493 	spin_lock_bh(&br->hash_lock);
494 
495 	/* If old entry was unassociated with any port, then delete it. */
496 	f = br_fdb_find(br, br->dev->dev_addr, 0);
497 	if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
498 	    !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags))
499 		fdb_delete_local(br, NULL, f);
500 
501 	fdb_add_local(br, NULL, newaddr, 0);
502 	vg = br_vlan_group(br);
503 	if (!vg || !vg->num_vlans)
504 		goto out;
505 	/* Now remove and add entries for every VLAN configured on the
506 	 * bridge.  This function runs under RTNL so the bitmap will not
507 	 * change from under us.
508 	 */
509 	list_for_each_entry(v, &vg->vlan_list, vlist) {
510 		if (!br_vlan_should_use(v))
511 			continue;
512 		f = br_fdb_find(br, br->dev->dev_addr, v->vid);
513 		if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
514 		    !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags))
515 			fdb_delete_local(br, NULL, f);
516 		fdb_add_local(br, NULL, newaddr, v->vid);
517 	}
518 out:
519 	spin_unlock_bh(&br->hash_lock);
520 }
521 
br_fdb_cleanup(struct work_struct * work)522 void br_fdb_cleanup(struct work_struct *work)
523 {
524 	struct net_bridge *br = container_of(work, struct net_bridge,
525 					     gc_work.work);
526 	struct net_bridge_fdb_entry *f = NULL;
527 	unsigned long delay = hold_time(br);
528 	unsigned long work_delay = delay;
529 	unsigned long now = jiffies;
530 
531 	/* this part is tricky, in order to avoid blocking learning and
532 	 * consequently forwarding, we rely on rcu to delete objects with
533 	 * delayed freeing allowing us to continue traversing
534 	 */
535 	rcu_read_lock();
536 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
537 		unsigned long this_timer = f->updated + delay;
538 
539 		if (test_bit(BR_FDB_STATIC, &f->flags) ||
540 		    test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags)) {
541 			if (test_bit(BR_FDB_NOTIFY, &f->flags)) {
542 				if (time_after(this_timer, now))
543 					work_delay = min(work_delay,
544 							 this_timer - now);
545 				else if (!test_and_set_bit(BR_FDB_NOTIFY_INACTIVE,
546 							   &f->flags))
547 					fdb_notify(br, f, RTM_NEWNEIGH, false);
548 			}
549 			continue;
550 		}
551 
552 		if (time_after(this_timer, now)) {
553 			work_delay = min(work_delay, this_timer - now);
554 		} else {
555 			spin_lock_bh(&br->hash_lock);
556 			if (!hlist_unhashed(&f->fdb_node))
557 				fdb_delete(br, f, true);
558 			spin_unlock_bh(&br->hash_lock);
559 		}
560 	}
561 	rcu_read_unlock();
562 
563 	/* Cleanup minimum 10 milliseconds apart */
564 	work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
565 	mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
566 }
567 
__fdb_flush_matches(const struct net_bridge * br,const struct net_bridge_fdb_entry * f,const struct net_bridge_fdb_flush_desc * desc)568 static bool __fdb_flush_matches(const struct net_bridge *br,
569 				const struct net_bridge_fdb_entry *f,
570 				const struct net_bridge_fdb_flush_desc *desc)
571 {
572 	const struct net_bridge_port *dst = READ_ONCE(f->dst);
573 	int port_ifidx = dst ? dst->dev->ifindex : br->dev->ifindex;
574 
575 	if (desc->vlan_id && desc->vlan_id != f->key.vlan_id)
576 		return false;
577 	if (desc->port_ifindex && desc->port_ifindex != port_ifidx)
578 		return false;
579 	if (desc->flags_mask && (f->flags & desc->flags_mask) != desc->flags)
580 		return false;
581 
582 	return true;
583 }
584 
585 /* Flush forwarding database entries matching the description */
br_fdb_flush(struct net_bridge * br,const struct net_bridge_fdb_flush_desc * desc)586 void br_fdb_flush(struct net_bridge *br,
587 		  const struct net_bridge_fdb_flush_desc *desc)
588 {
589 	struct net_bridge_fdb_entry *f;
590 
591 	rcu_read_lock();
592 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
593 		if (!__fdb_flush_matches(br, f, desc))
594 			continue;
595 
596 		spin_lock_bh(&br->hash_lock);
597 		if (!hlist_unhashed(&f->fdb_node))
598 			fdb_delete(br, f, true);
599 		spin_unlock_bh(&br->hash_lock);
600 	}
601 	rcu_read_unlock();
602 }
603 
__ndm_state_to_fdb_flags(u16 ndm_state)604 static unsigned long __ndm_state_to_fdb_flags(u16 ndm_state)
605 {
606 	unsigned long flags = 0;
607 
608 	if (ndm_state & NUD_PERMANENT)
609 		__set_bit(BR_FDB_LOCAL, &flags);
610 	if (ndm_state & NUD_NOARP)
611 		__set_bit(BR_FDB_STATIC, &flags);
612 
613 	return flags;
614 }
615 
__ndm_flags_to_fdb_flags(u8 ndm_flags)616 static unsigned long __ndm_flags_to_fdb_flags(u8 ndm_flags)
617 {
618 	unsigned long flags = 0;
619 
620 	if (ndm_flags & NTF_USE)
621 		__set_bit(BR_FDB_ADDED_BY_USER, &flags);
622 	if (ndm_flags & NTF_EXT_LEARNED)
623 		__set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &flags);
624 	if (ndm_flags & NTF_OFFLOADED)
625 		__set_bit(BR_FDB_OFFLOADED, &flags);
626 	if (ndm_flags & NTF_STICKY)
627 		__set_bit(BR_FDB_STICKY, &flags);
628 
629 	return flags;
630 }
631 
__fdb_flush_validate_ifindex(const struct net_bridge * br,int ifindex,struct netlink_ext_ack * extack)632 static int __fdb_flush_validate_ifindex(const struct net_bridge *br,
633 					int ifindex,
634 					struct netlink_ext_ack *extack)
635 {
636 	const struct net_device *dev;
637 
638 	dev = __dev_get_by_index(dev_net(br->dev), ifindex);
639 	if (!dev) {
640 		NL_SET_ERR_MSG_MOD(extack, "Unknown flush device ifindex");
641 		return -ENODEV;
642 	}
643 	if (!netif_is_bridge_master(dev) && !netif_is_bridge_port(dev)) {
644 		NL_SET_ERR_MSG_MOD(extack, "Flush device is not a bridge or bridge port");
645 		return -EINVAL;
646 	}
647 	if (netif_is_bridge_master(dev) && dev != br->dev) {
648 		NL_SET_ERR_MSG_MOD(extack,
649 				   "Flush bridge device does not match target bridge device");
650 		return -EINVAL;
651 	}
652 	if (netif_is_bridge_port(dev)) {
653 		struct net_bridge_port *p = br_port_get_rtnl(dev);
654 
655 		if (p->br != br) {
656 			NL_SET_ERR_MSG_MOD(extack, "Port belongs to a different bridge device");
657 			return -EINVAL;
658 		}
659 	}
660 
661 	return 0;
662 }
663 
br_fdb_delete_bulk(struct ndmsg * ndm,struct nlattr * tb[],struct net_device * dev,u16 vid,struct netlink_ext_ack * extack)664 int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr *tb[],
665 		       struct net_device *dev, u16 vid,
666 		       struct netlink_ext_ack *extack)
667 {
668 	u8 ndm_flags = ndm->ndm_flags & ~FDB_FLUSH_IGNORED_NDM_FLAGS;
669 	struct net_bridge_fdb_flush_desc desc = { .vlan_id = vid };
670 	struct net_bridge_port *p = NULL;
671 	struct net_bridge *br;
672 
673 	if (netif_is_bridge_master(dev)) {
674 		br = netdev_priv(dev);
675 	} else {
676 		p = br_port_get_rtnl(dev);
677 		if (!p) {
678 			NL_SET_ERR_MSG_MOD(extack, "Device is not a bridge port");
679 			return -EINVAL;
680 		}
681 		br = p->br;
682 	}
683 
684 	if (ndm_flags & ~FDB_FLUSH_ALLOWED_NDM_FLAGS) {
685 		NL_SET_ERR_MSG(extack, "Unsupported fdb flush ndm flag bits set");
686 		return -EINVAL;
687 	}
688 	if (ndm->ndm_state & ~FDB_FLUSH_ALLOWED_NDM_STATES) {
689 		NL_SET_ERR_MSG(extack, "Unsupported fdb flush ndm state bits set");
690 		return -EINVAL;
691 	}
692 
693 	desc.flags |= __ndm_state_to_fdb_flags(ndm->ndm_state);
694 	desc.flags |= __ndm_flags_to_fdb_flags(ndm_flags);
695 	if (tb[NDA_NDM_STATE_MASK]) {
696 		u16 ndm_state_mask = nla_get_u16(tb[NDA_NDM_STATE_MASK]);
697 
698 		desc.flags_mask |= __ndm_state_to_fdb_flags(ndm_state_mask);
699 	}
700 	if (tb[NDA_NDM_FLAGS_MASK]) {
701 		u8 ndm_flags_mask = nla_get_u8(tb[NDA_NDM_FLAGS_MASK]);
702 
703 		desc.flags_mask |= __ndm_flags_to_fdb_flags(ndm_flags_mask);
704 	}
705 	if (tb[NDA_IFINDEX]) {
706 		int err, ifidx = nla_get_s32(tb[NDA_IFINDEX]);
707 
708 		err = __fdb_flush_validate_ifindex(br, ifidx, extack);
709 		if (err)
710 			return err;
711 		desc.port_ifindex = ifidx;
712 	} else if (p) {
713 		/* flush was invoked with port device and NTF_MASTER */
714 		desc.port_ifindex = p->dev->ifindex;
715 	}
716 
717 	br_debug(br, "flushing port ifindex: %d vlan id: %u flags: 0x%lx flags mask: 0x%lx\n",
718 		 desc.port_ifindex, desc.vlan_id, desc.flags, desc.flags_mask);
719 
720 	br_fdb_flush(br, &desc);
721 
722 	return 0;
723 }
724 
725 /* Flush all entries referring to a specific port.
726  * if do_all is set also flush static entries
727  * if vid is set delete all entries that match the vlan_id
728  */
br_fdb_delete_by_port(struct net_bridge * br,const struct net_bridge_port * p,u16 vid,int do_all)729 void br_fdb_delete_by_port(struct net_bridge *br,
730 			   const struct net_bridge_port *p,
731 			   u16 vid,
732 			   int do_all)
733 {
734 	struct net_bridge_fdb_entry *f;
735 	struct hlist_node *tmp;
736 
737 	spin_lock_bh(&br->hash_lock);
738 	hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
739 		if (f->dst != p)
740 			continue;
741 
742 		if (!do_all)
743 			if (test_bit(BR_FDB_STATIC, &f->flags) ||
744 			    (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags) &&
745 			     !test_bit(BR_FDB_OFFLOADED, &f->flags)) ||
746 			    (vid && f->key.vlan_id != vid))
747 				continue;
748 
749 		if (test_bit(BR_FDB_LOCAL, &f->flags))
750 			fdb_delete_local(br, p, f);
751 		else
752 			fdb_delete(br, f, true);
753 	}
754 	spin_unlock_bh(&br->hash_lock);
755 }
756 
757 #if IS_ENABLED(CONFIG_ATM_LANE)
758 /* Interface used by ATM LANE hook to test
759  * if an addr is on some other bridge port */
br_fdb_test_addr(struct net_device * dev,unsigned char * addr)760 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
761 {
762 	struct net_bridge_fdb_entry *fdb;
763 	struct net_bridge_port *port;
764 	int ret;
765 
766 	rcu_read_lock();
767 	port = br_port_get_rcu(dev);
768 	if (!port)
769 		ret = 0;
770 	else {
771 		const struct net_bridge_port *dst = NULL;
772 
773 		fdb = br_fdb_find_rcu(port->br, addr, 0);
774 		if (fdb)
775 			dst = READ_ONCE(fdb->dst);
776 
777 		ret = dst && dst->dev != dev &&
778 		      dst->state == BR_STATE_FORWARDING;
779 	}
780 	rcu_read_unlock();
781 
782 	return ret;
783 }
784 #endif /* CONFIG_ATM_LANE */
785 
786 /*
787  * Fill buffer with forwarding table records in
788  * the API format.
789  */
br_fdb_fillbuf(struct net_bridge * br,void * buf,unsigned long maxnum,unsigned long skip)790 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
791 		   unsigned long maxnum, unsigned long skip)
792 {
793 	struct net_bridge_fdb_entry *f;
794 	struct __fdb_entry *fe = buf;
795 	int num = 0;
796 
797 	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
798 
799 	rcu_read_lock();
800 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
801 		if (num >= maxnum)
802 			break;
803 
804 		if (has_expired(br, f))
805 			continue;
806 
807 		/* ignore pseudo entry for local MAC address */
808 		if (!f->dst)
809 			continue;
810 
811 		if (skip) {
812 			--skip;
813 			continue;
814 		}
815 
816 		/* convert from internal format to API */
817 		memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN);
818 
819 		/* due to ABI compat need to split into hi/lo */
820 		fe->port_no = f->dst->port_no;
821 		fe->port_hi = f->dst->port_no >> 8;
822 
823 		fe->is_local = test_bit(BR_FDB_LOCAL, &f->flags);
824 		if (!test_bit(BR_FDB_STATIC, &f->flags))
825 			fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
826 		++fe;
827 		++num;
828 	}
829 	rcu_read_unlock();
830 
831 	return num;
832 }
833 
834 /* 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)835 int br_fdb_add_local(struct net_bridge *br, struct net_bridge_port *source,
836 		     const unsigned char *addr, u16 vid)
837 {
838 	int ret;
839 
840 	spin_lock_bh(&br->hash_lock);
841 	ret = fdb_add_local(br, source, addr, vid);
842 	spin_unlock_bh(&br->hash_lock);
843 	return ret;
844 }
845 
846 /* returns true if the fdb was modified */
__fdb_mark_active(struct net_bridge_fdb_entry * fdb)847 static bool __fdb_mark_active(struct net_bridge_fdb_entry *fdb)
848 {
849 	return !!(test_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags) &&
850 		  test_and_clear_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags));
851 }
852 
br_fdb_update(struct net_bridge * br,struct net_bridge_port * source,const unsigned char * addr,u16 vid,unsigned long flags)853 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
854 		   const unsigned char *addr, u16 vid, unsigned long flags)
855 {
856 	struct net_bridge_fdb_entry *fdb;
857 
858 	/* some users want to always flood. */
859 	if (hold_time(br) == 0)
860 		return;
861 
862 	fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
863 	if (likely(fdb)) {
864 		/* attempt to update an entry for a local interface */
865 		if (unlikely(test_bit(BR_FDB_LOCAL, &fdb->flags))) {
866 			if (net_ratelimit())
867 				br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
868 					source->dev->name, addr, vid);
869 		} else {
870 			unsigned long now = jiffies;
871 			bool fdb_modified = false;
872 
873 			if (now != fdb->updated) {
874 				fdb->updated = now;
875 				fdb_modified = __fdb_mark_active(fdb);
876 			}
877 
878 			/* fastpath: update of existing entry */
879 			if (unlikely(source != READ_ONCE(fdb->dst) &&
880 				     !test_bit(BR_FDB_STICKY, &fdb->flags))) {
881 				br_switchdev_fdb_notify(br, fdb, RTM_DELNEIGH);
882 				WRITE_ONCE(fdb->dst, source);
883 				fdb_modified = true;
884 				/* Take over HW learned entry */
885 				if (unlikely(test_bit(BR_FDB_ADDED_BY_EXT_LEARN,
886 						      &fdb->flags)))
887 					clear_bit(BR_FDB_ADDED_BY_EXT_LEARN,
888 						  &fdb->flags);
889 				/* Clear locked flag when roaming to an
890 				 * unlocked port.
891 				 */
892 				if (unlikely(test_bit(BR_FDB_LOCKED, &fdb->flags)))
893 					clear_bit(BR_FDB_LOCKED, &fdb->flags);
894 			}
895 
896 			if (unlikely(test_bit(BR_FDB_ADDED_BY_USER, &flags)))
897 				set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
898 			if (unlikely(fdb_modified)) {
899 				trace_br_fdb_update(br, source, addr, vid, flags);
900 				fdb_notify(br, fdb, RTM_NEWNEIGH, true);
901 			}
902 		}
903 	} else {
904 		spin_lock(&br->hash_lock);
905 		fdb = fdb_create(br, source, addr, vid, flags);
906 		if (fdb) {
907 			trace_br_fdb_update(br, source, addr, vid, flags);
908 			fdb_notify(br, fdb, RTM_NEWNEIGH, true);
909 		}
910 		/* else  we lose race and someone else inserts
911 		 * it first, don't bother updating
912 		 */
913 		spin_unlock(&br->hash_lock);
914 	}
915 }
916 
917 /* 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)918 int br_fdb_dump(struct sk_buff *skb,
919 		struct netlink_callback *cb,
920 		struct net_device *dev,
921 		struct net_device *filter_dev,
922 		int *idx)
923 {
924 	struct net_bridge *br = netdev_priv(dev);
925 	struct net_bridge_fdb_entry *f;
926 	int err = 0;
927 
928 	if (!netif_is_bridge_master(dev))
929 		return err;
930 
931 	if (!filter_dev) {
932 		err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
933 		if (err < 0)
934 			return err;
935 	}
936 
937 	rcu_read_lock();
938 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
939 		if (*idx < cb->args[2])
940 			goto skip;
941 		if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
942 			if (filter_dev != dev)
943 				goto skip;
944 			/* !f->dst is a special case for bridge
945 			 * It means the MAC belongs to the bridge
946 			 * Therefore need a little more filtering
947 			 * we only want to dump the !f->dst case
948 			 */
949 			if (f->dst)
950 				goto skip;
951 		}
952 		if (!filter_dev && f->dst)
953 			goto skip;
954 
955 		err = fdb_fill_info(skb, br, f,
956 				    NETLINK_CB(cb->skb).portid,
957 				    cb->nlh->nlmsg_seq,
958 				    RTM_NEWNEIGH,
959 				    NLM_F_MULTI);
960 		if (err < 0)
961 			break;
962 skip:
963 		*idx += 1;
964 	}
965 	rcu_read_unlock();
966 
967 	return err;
968 }
969 
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)970 int br_fdb_get(struct sk_buff *skb,
971 	       struct nlattr *tb[],
972 	       struct net_device *dev,
973 	       const unsigned char *addr,
974 	       u16 vid, u32 portid, u32 seq,
975 	       struct netlink_ext_ack *extack)
976 {
977 	struct net_bridge *br = netdev_priv(dev);
978 	struct net_bridge_fdb_entry *f;
979 	int err = 0;
980 
981 	rcu_read_lock();
982 	f = br_fdb_find_rcu(br, addr, vid);
983 	if (!f) {
984 		NL_SET_ERR_MSG(extack, "Fdb entry not found");
985 		err = -ENOENT;
986 		goto errout;
987 	}
988 
989 	err = fdb_fill_info(skb, br, f, portid, seq,
990 			    RTM_NEWNEIGH, 0);
991 errout:
992 	rcu_read_unlock();
993 	return err;
994 }
995 
996 /* returns true if the fdb is modified */
fdb_handle_notify(struct net_bridge_fdb_entry * fdb,u8 notify)997 static bool fdb_handle_notify(struct net_bridge_fdb_entry *fdb, u8 notify)
998 {
999 	bool modified = false;
1000 
1001 	/* allow to mark an entry as inactive, usually done on creation */
1002 	if ((notify & FDB_NOTIFY_INACTIVE_BIT) &&
1003 	    !test_and_set_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags))
1004 		modified = true;
1005 
1006 	if ((notify & FDB_NOTIFY_BIT) &&
1007 	    !test_and_set_bit(BR_FDB_NOTIFY, &fdb->flags)) {
1008 		/* enabled activity tracking */
1009 		modified = true;
1010 	} else if (!(notify & FDB_NOTIFY_BIT) &&
1011 		   test_and_clear_bit(BR_FDB_NOTIFY, &fdb->flags)) {
1012 		/* disabled activity tracking, clear notify state */
1013 		clear_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags);
1014 		modified = true;
1015 	}
1016 
1017 	return modified;
1018 }
1019 
1020 /* 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[])1021 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
1022 			 const u8 *addr, struct ndmsg *ndm, u16 flags, u16 vid,
1023 			 struct nlattr *nfea_tb[])
1024 {
1025 	bool is_sticky = !!(ndm->ndm_flags & NTF_STICKY);
1026 	bool refresh = !nfea_tb[NFEA_DONT_REFRESH];
1027 	struct net_bridge_fdb_entry *fdb;
1028 	u16 state = ndm->ndm_state;
1029 	bool modified = false;
1030 	u8 notify = 0;
1031 
1032 	/* If the port cannot learn allow only local and static entries */
1033 	if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
1034 	    !(source->state == BR_STATE_LEARNING ||
1035 	      source->state == BR_STATE_FORWARDING))
1036 		return -EPERM;
1037 
1038 	if (!source && !(state & NUD_PERMANENT)) {
1039 		pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
1040 			br->dev->name);
1041 		return -EINVAL;
1042 	}
1043 
1044 	if (is_sticky && (state & NUD_PERMANENT))
1045 		return -EINVAL;
1046 
1047 	if (nfea_tb[NFEA_ACTIVITY_NOTIFY]) {
1048 		notify = nla_get_u8(nfea_tb[NFEA_ACTIVITY_NOTIFY]);
1049 		if ((notify & ~BR_FDB_NOTIFY_SETTABLE_BITS) ||
1050 		    (notify & BR_FDB_NOTIFY_SETTABLE_BITS) == FDB_NOTIFY_INACTIVE_BIT)
1051 			return -EINVAL;
1052 	}
1053 
1054 	fdb = br_fdb_find(br, addr, vid);
1055 	if (fdb == NULL) {
1056 		if (!(flags & NLM_F_CREATE))
1057 			return -ENOENT;
1058 
1059 		fdb = fdb_create(br, source, addr, vid, 0);
1060 		if (!fdb)
1061 			return -ENOMEM;
1062 
1063 		modified = true;
1064 	} else {
1065 		if (flags & NLM_F_EXCL)
1066 			return -EEXIST;
1067 
1068 		if (READ_ONCE(fdb->dst) != source) {
1069 			WRITE_ONCE(fdb->dst, source);
1070 			modified = true;
1071 		}
1072 	}
1073 
1074 	if (fdb_to_nud(br, fdb) != state) {
1075 		if (state & NUD_PERMANENT) {
1076 			set_bit(BR_FDB_LOCAL, &fdb->flags);
1077 			if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
1078 				fdb_add_hw_addr(br, addr);
1079 		} else if (state & NUD_NOARP) {
1080 			clear_bit(BR_FDB_LOCAL, &fdb->flags);
1081 			if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
1082 				fdb_add_hw_addr(br, addr);
1083 		} else {
1084 			clear_bit(BR_FDB_LOCAL, &fdb->flags);
1085 			if (test_and_clear_bit(BR_FDB_STATIC, &fdb->flags))
1086 				fdb_del_hw_addr(br, addr);
1087 		}
1088 
1089 		modified = true;
1090 	}
1091 
1092 	if (is_sticky != test_bit(BR_FDB_STICKY, &fdb->flags)) {
1093 		change_bit(BR_FDB_STICKY, &fdb->flags);
1094 		modified = true;
1095 	}
1096 
1097 	if (test_and_clear_bit(BR_FDB_LOCKED, &fdb->flags))
1098 		modified = true;
1099 
1100 	if (fdb_handle_notify(fdb, notify))
1101 		modified = true;
1102 
1103 	set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
1104 
1105 	fdb->used = jiffies;
1106 	if (modified) {
1107 		if (refresh)
1108 			fdb->updated = jiffies;
1109 		fdb_notify(br, fdb, RTM_NEWNEIGH, true);
1110 	}
1111 
1112 	return 0;
1113 }
1114 
__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)1115 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
1116 			struct net_bridge_port *p, const unsigned char *addr,
1117 			u16 nlh_flags, u16 vid, struct nlattr *nfea_tb[],
1118 			struct netlink_ext_ack *extack)
1119 {
1120 	int err = 0;
1121 
1122 	if (ndm->ndm_flags & NTF_USE) {
1123 		if (!p) {
1124 			pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
1125 				br->dev->name);
1126 			return -EINVAL;
1127 		}
1128 		if (!nbp_state_should_learn(p))
1129 			return 0;
1130 
1131 		local_bh_disable();
1132 		rcu_read_lock();
1133 		br_fdb_update(br, p, addr, vid, BIT(BR_FDB_ADDED_BY_USER));
1134 		rcu_read_unlock();
1135 		local_bh_enable();
1136 	} else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
1137 		if (!p && !(ndm->ndm_state & NUD_PERMANENT)) {
1138 			NL_SET_ERR_MSG_MOD(extack,
1139 					   "FDB entry towards bridge must be permanent");
1140 			return -EINVAL;
1141 		}
1142 		err = br_fdb_external_learn_add(br, p, addr, vid, false, true);
1143 	} else {
1144 		spin_lock_bh(&br->hash_lock);
1145 		err = fdb_add_entry(br, p, addr, ndm, nlh_flags, vid, nfea_tb);
1146 		spin_unlock_bh(&br->hash_lock);
1147 	}
1148 
1149 	return err;
1150 }
1151 
1152 static const struct nla_policy br_nda_fdb_pol[NFEA_MAX + 1] = {
1153 	[NFEA_ACTIVITY_NOTIFY]	= { .type = NLA_U8 },
1154 	[NFEA_DONT_REFRESH]	= { .type = NLA_FLAG },
1155 };
1156 
1157 /* 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)1158 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
1159 	       struct net_device *dev,
1160 	       const unsigned char *addr, u16 vid, u16 nlh_flags,
1161 	       struct netlink_ext_ack *extack)
1162 {
1163 	struct nlattr *nfea_tb[NFEA_MAX + 1], *attr;
1164 	struct net_bridge_vlan_group *vg;
1165 	struct net_bridge_port *p = NULL;
1166 	struct net_bridge_vlan *v;
1167 	struct net_bridge *br = NULL;
1168 	u32 ext_flags = 0;
1169 	int err = 0;
1170 
1171 	trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);
1172 
1173 	if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
1174 		pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
1175 		return -EINVAL;
1176 	}
1177 
1178 	if (is_zero_ether_addr(addr)) {
1179 		pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
1180 		return -EINVAL;
1181 	}
1182 
1183 	if (netif_is_bridge_master(dev)) {
1184 		br = netdev_priv(dev);
1185 		vg = br_vlan_group(br);
1186 	} else {
1187 		p = br_port_get_rtnl(dev);
1188 		if (!p) {
1189 			pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
1190 				dev->name);
1191 			return -EINVAL;
1192 		}
1193 		br = p->br;
1194 		vg = nbp_vlan_group(p);
1195 	}
1196 
1197 	if (tb[NDA_FLAGS_EXT])
1198 		ext_flags = nla_get_u32(tb[NDA_FLAGS_EXT]);
1199 
1200 	if (ext_flags & NTF_EXT_LOCKED) {
1201 		NL_SET_ERR_MSG_MOD(extack, "Cannot add FDB entry with \"locked\" flag set");
1202 		return -EINVAL;
1203 	}
1204 
1205 	if (tb[NDA_FDB_EXT_ATTRS]) {
1206 		attr = tb[NDA_FDB_EXT_ATTRS];
1207 		err = nla_parse_nested(nfea_tb, NFEA_MAX, attr,
1208 				       br_nda_fdb_pol, extack);
1209 		if (err)
1210 			return err;
1211 	} else {
1212 		memset(nfea_tb, 0, sizeof(struct nlattr *) * (NFEA_MAX + 1));
1213 	}
1214 
1215 	if (vid) {
1216 		v = br_vlan_find(vg, vid);
1217 		if (!v || !br_vlan_should_use(v)) {
1218 			pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1219 			return -EINVAL;
1220 		}
1221 
1222 		/* VID was specified, so use it. */
1223 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid, nfea_tb,
1224 				   extack);
1225 	} else {
1226 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0, nfea_tb,
1227 				   extack);
1228 		if (err || !vg || !vg->num_vlans)
1229 			goto out;
1230 
1231 		/* We have vlans configured on this port and user didn't
1232 		 * specify a VLAN.  To be nice, add/update entry for every
1233 		 * vlan on this port.
1234 		 */
1235 		list_for_each_entry(v, &vg->vlan_list, vlist) {
1236 			if (!br_vlan_should_use(v))
1237 				continue;
1238 			err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid,
1239 					   nfea_tb, extack);
1240 			if (err)
1241 				goto out;
1242 		}
1243 	}
1244 
1245 out:
1246 	return err;
1247 }
1248 
fdb_delete_by_addr_and_port(struct net_bridge * br,const struct net_bridge_port * p,const u8 * addr,u16 vlan)1249 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
1250 				       const struct net_bridge_port *p,
1251 				       const u8 *addr, u16 vlan)
1252 {
1253 	struct net_bridge_fdb_entry *fdb;
1254 
1255 	fdb = br_fdb_find(br, addr, vlan);
1256 	if (!fdb || READ_ONCE(fdb->dst) != p)
1257 		return -ENOENT;
1258 
1259 	fdb_delete(br, fdb, true);
1260 
1261 	return 0;
1262 }
1263 
__br_fdb_delete(struct net_bridge * br,const struct net_bridge_port * p,const unsigned char * addr,u16 vid)1264 static int __br_fdb_delete(struct net_bridge *br,
1265 			   const struct net_bridge_port *p,
1266 			   const unsigned char *addr, u16 vid)
1267 {
1268 	int err;
1269 
1270 	spin_lock_bh(&br->hash_lock);
1271 	err = fdb_delete_by_addr_and_port(br, p, addr, vid);
1272 	spin_unlock_bh(&br->hash_lock);
1273 
1274 	return err;
1275 }
1276 
1277 /* 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)1278 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
1279 		  struct net_device *dev,
1280 		  const unsigned char *addr, u16 vid,
1281 		  struct netlink_ext_ack *extack)
1282 {
1283 	struct net_bridge_vlan_group *vg;
1284 	struct net_bridge_port *p = NULL;
1285 	struct net_bridge_vlan *v;
1286 	struct net_bridge *br;
1287 	int err;
1288 
1289 	if (netif_is_bridge_master(dev)) {
1290 		br = netdev_priv(dev);
1291 		vg = br_vlan_group(br);
1292 	} else {
1293 		p = br_port_get_rtnl(dev);
1294 		if (!p) {
1295 			pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1296 				dev->name);
1297 			return -EINVAL;
1298 		}
1299 		vg = nbp_vlan_group(p);
1300 		br = p->br;
1301 	}
1302 
1303 	if (vid) {
1304 		v = br_vlan_find(vg, vid);
1305 		if (!v) {
1306 			pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1307 			return -EINVAL;
1308 		}
1309 
1310 		err = __br_fdb_delete(br, p, addr, vid);
1311 	} else {
1312 		err = -ENOENT;
1313 		err &= __br_fdb_delete(br, p, addr, 0);
1314 		if (!vg || !vg->num_vlans)
1315 			return err;
1316 
1317 		list_for_each_entry(v, &vg->vlan_list, vlist) {
1318 			if (!br_vlan_should_use(v))
1319 				continue;
1320 			err &= __br_fdb_delete(br, p, addr, v->vid);
1321 		}
1322 	}
1323 
1324 	return err;
1325 }
1326 
br_fdb_sync_static(struct net_bridge * br,struct net_bridge_port * p)1327 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1328 {
1329 	struct net_bridge_fdb_entry *f, *tmp;
1330 	int err = 0;
1331 
1332 	ASSERT_RTNL();
1333 
1334 	/* the key here is that static entries change only under rtnl */
1335 	rcu_read_lock();
1336 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1337 		/* We only care for static entries */
1338 		if (!test_bit(BR_FDB_STATIC, &f->flags))
1339 			continue;
1340 		err = dev_uc_add(p->dev, f->key.addr.addr);
1341 		if (err)
1342 			goto rollback;
1343 	}
1344 done:
1345 	rcu_read_unlock();
1346 
1347 	return err;
1348 
1349 rollback:
1350 	hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) {
1351 		/* We only care for static entries */
1352 		if (!test_bit(BR_FDB_STATIC, &tmp->flags))
1353 			continue;
1354 		if (tmp == f)
1355 			break;
1356 		dev_uc_del(p->dev, tmp->key.addr.addr);
1357 	}
1358 
1359 	goto done;
1360 }
1361 
br_fdb_unsync_static(struct net_bridge * br,struct net_bridge_port * p)1362 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1363 {
1364 	struct net_bridge_fdb_entry *f;
1365 
1366 	ASSERT_RTNL();
1367 
1368 	rcu_read_lock();
1369 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1370 		/* We only care for static entries */
1371 		if (!test_bit(BR_FDB_STATIC, &f->flags))
1372 			continue;
1373 
1374 		dev_uc_del(p->dev, f->key.addr.addr);
1375 	}
1376 	rcu_read_unlock();
1377 }
1378 
br_fdb_external_learn_add(struct net_bridge * br,struct net_bridge_port * p,const unsigned char * addr,u16 vid,bool locked,bool swdev_notify)1379 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1380 			      const unsigned char *addr, u16 vid, bool locked,
1381 			      bool swdev_notify)
1382 {
1383 	struct net_bridge_fdb_entry *fdb;
1384 	bool modified = false;
1385 	int err = 0;
1386 
1387 	trace_br_fdb_external_learn_add(br, p, addr, vid);
1388 
1389 	if (locked && (!p || !(p->flags & BR_PORT_MAB)))
1390 		return -EINVAL;
1391 
1392 	spin_lock_bh(&br->hash_lock);
1393 
1394 	fdb = br_fdb_find(br, addr, vid);
1395 	if (!fdb) {
1396 		unsigned long flags = BIT(BR_FDB_ADDED_BY_EXT_LEARN);
1397 
1398 		if (swdev_notify)
1399 			flags |= BIT(BR_FDB_ADDED_BY_USER);
1400 
1401 		if (!p)
1402 			flags |= BIT(BR_FDB_LOCAL);
1403 
1404 		if (locked)
1405 			flags |= BIT(BR_FDB_LOCKED);
1406 
1407 		fdb = fdb_create(br, p, addr, vid, flags);
1408 		if (!fdb) {
1409 			err = -ENOMEM;
1410 			goto err_unlock;
1411 		}
1412 		fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1413 	} else {
1414 		if (locked &&
1415 		    (!test_bit(BR_FDB_LOCKED, &fdb->flags) ||
1416 		     READ_ONCE(fdb->dst) != p)) {
1417 			err = -EINVAL;
1418 			goto err_unlock;
1419 		}
1420 
1421 		fdb->updated = jiffies;
1422 
1423 		if (READ_ONCE(fdb->dst) != p) {
1424 			WRITE_ONCE(fdb->dst, p);
1425 			modified = true;
1426 		}
1427 
1428 		if (test_and_set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) {
1429 			/* Refresh entry */
1430 			fdb->used = jiffies;
1431 		} else {
1432 			modified = true;
1433 		}
1434 
1435 		if (locked != test_bit(BR_FDB_LOCKED, &fdb->flags)) {
1436 			change_bit(BR_FDB_LOCKED, &fdb->flags);
1437 			modified = true;
1438 		}
1439 
1440 		if (swdev_notify)
1441 			set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
1442 
1443 		if (!p)
1444 			set_bit(BR_FDB_LOCAL, &fdb->flags);
1445 
1446 		if (modified)
1447 			fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1448 	}
1449 
1450 err_unlock:
1451 	spin_unlock_bh(&br->hash_lock);
1452 
1453 	return err;
1454 }
1455 
br_fdb_external_learn_del(struct net_bridge * br,struct net_bridge_port * p,const unsigned char * addr,u16 vid,bool swdev_notify)1456 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1457 			      const unsigned char *addr, u16 vid,
1458 			      bool swdev_notify)
1459 {
1460 	struct net_bridge_fdb_entry *fdb;
1461 	int err = 0;
1462 
1463 	spin_lock_bh(&br->hash_lock);
1464 
1465 	fdb = br_fdb_find(br, addr, vid);
1466 	if (fdb && test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
1467 		fdb_delete(br, fdb, swdev_notify);
1468 	else
1469 		err = -ENOENT;
1470 
1471 	spin_unlock_bh(&br->hash_lock);
1472 
1473 	return err;
1474 }
1475 
br_fdb_offloaded_set(struct net_bridge * br,struct net_bridge_port * p,const unsigned char * addr,u16 vid,bool offloaded)1476 void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1477 			  const unsigned char *addr, u16 vid, bool offloaded)
1478 {
1479 	struct net_bridge_fdb_entry *fdb;
1480 
1481 	spin_lock_bh(&br->hash_lock);
1482 
1483 	fdb = br_fdb_find(br, addr, vid);
1484 	if (fdb && offloaded != test_bit(BR_FDB_OFFLOADED, &fdb->flags))
1485 		change_bit(BR_FDB_OFFLOADED, &fdb->flags);
1486 
1487 	spin_unlock_bh(&br->hash_lock);
1488 }
1489 
br_fdb_clear_offload(const struct net_device * dev,u16 vid)1490 void br_fdb_clear_offload(const struct net_device *dev, u16 vid)
1491 {
1492 	struct net_bridge_fdb_entry *f;
1493 	struct net_bridge_port *p;
1494 
1495 	ASSERT_RTNL();
1496 
1497 	p = br_port_get_rtnl(dev);
1498 	if (!p)
1499 		return;
1500 
1501 	spin_lock_bh(&p->br->hash_lock);
1502 	hlist_for_each_entry(f, &p->br->fdb_list, fdb_node) {
1503 		if (f->dst == p && f->key.vlan_id == vid)
1504 			clear_bit(BR_FDB_OFFLOADED, &f->flags);
1505 	}
1506 	spin_unlock_bh(&p->br->hash_lock);
1507 }
1508 EXPORT_SYMBOL_GPL(br_fdb_clear_offload);
1509