netlink: Rename pid to portid to avoid confusion
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / bridge / br_fdb.c
1 /*
2 * Forwarding database
3 * Linux ethernet bridge
4 *
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/rculist.h>
17 #include <linux/spinlock.h>
18 #include <linux/times.h>
19 #include <linux/netdevice.h>
20 #include <linux/etherdevice.h>
21 #include <linux/jhash.h>
22 #include <linux/random.h>
23 #include <linux/slab.h>
24 #include <linux/atomic.h>
25 #include <asm/unaligned.h>
26 #include "br_private.h"
27
28 static struct kmem_cache *br_fdb_cache __read_mostly;
29 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
30 const unsigned char *addr);
31 static void fdb_notify(struct net_bridge *br,
32 const struct net_bridge_fdb_entry *, int);
33
34 static u32 fdb_salt __read_mostly;
35
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 get_random_bytes(&fdb_salt, sizeof(fdb_salt));
46 return 0;
47 }
48
49 void br_fdb_fini(void)
50 {
51 kmem_cache_destroy(br_fdb_cache);
52 }
53
54
55 /* if topology_changing then use forward_delay (default 15 sec)
56 * otherwise keep longer (default 5 minutes)
57 */
58 static inline unsigned long hold_time(const struct net_bridge *br)
59 {
60 return br->topology_change ? br->forward_delay : br->ageing_time;
61 }
62
63 static inline int has_expired(const struct net_bridge *br,
64 const struct net_bridge_fdb_entry *fdb)
65 {
66 return !fdb->is_static &&
67 time_before_eq(fdb->updated + hold_time(br), jiffies);
68 }
69
70 static inline int br_mac_hash(const unsigned char *mac)
71 {
72 /* use 1 byte of OUI cnd 3 bytes of NIC */
73 u32 key = get_unaligned((u32 *)(mac + 2));
74 return jhash_1word(key, fdb_salt) & (BR_HASH_SIZE - 1);
75 }
76
77 static void fdb_rcu_free(struct rcu_head *head)
78 {
79 struct net_bridge_fdb_entry *ent
80 = container_of(head, struct net_bridge_fdb_entry, rcu);
81 kmem_cache_free(br_fdb_cache, ent);
82 }
83
84 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
85 {
86 hlist_del_rcu(&f->hlist);
87 fdb_notify(br, f, RTM_DELNEIGH);
88 call_rcu(&f->rcu, fdb_rcu_free);
89 }
90
91 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
92 {
93 struct net_bridge *br = p->br;
94 int i;
95
96 spin_lock_bh(&br->hash_lock);
97
98 /* Search all chains since old address/hash is unknown */
99 for (i = 0; i < BR_HASH_SIZE; i++) {
100 struct hlist_node *h;
101 hlist_for_each(h, &br->hash[i]) {
102 struct net_bridge_fdb_entry *f;
103
104 f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
105 if (f->dst == p && f->is_local) {
106 /* maybe another port has same hw addr? */
107 struct net_bridge_port *op;
108 list_for_each_entry(op, &br->port_list, list) {
109 if (op != p &&
110 ether_addr_equal(op->dev->dev_addr,
111 f->addr.addr)) {
112 f->dst = op;
113 goto insert;
114 }
115 }
116
117 /* delete old one */
118 fdb_delete(br, f);
119 goto insert;
120 }
121 }
122 }
123 insert:
124 /* insert new address, may fail if invalid address or dup. */
125 fdb_insert(br, p, newaddr);
126
127 spin_unlock_bh(&br->hash_lock);
128 }
129
130 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
131 {
132 struct net_bridge_fdb_entry *f;
133
134 /* If old entry was unassociated with any port, then delete it. */
135 f = __br_fdb_get(br, br->dev->dev_addr);
136 if (f && f->is_local && !f->dst)
137 fdb_delete(br, f);
138
139 fdb_insert(br, NULL, newaddr);
140 }
141
142 void br_fdb_cleanup(unsigned long _data)
143 {
144 struct net_bridge *br = (struct net_bridge *)_data;
145 unsigned long delay = hold_time(br);
146 unsigned long next_timer = jiffies + br->ageing_time;
147 int i;
148
149 spin_lock(&br->hash_lock);
150 for (i = 0; i < BR_HASH_SIZE; i++) {
151 struct net_bridge_fdb_entry *f;
152 struct hlist_node *h, *n;
153
154 hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
155 unsigned long this_timer;
156 if (f->is_static)
157 continue;
158 this_timer = f->updated + delay;
159 if (time_before_eq(this_timer, jiffies))
160 fdb_delete(br, f);
161 else if (time_before(this_timer, next_timer))
162 next_timer = this_timer;
163 }
164 }
165 spin_unlock(&br->hash_lock);
166
167 mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
168 }
169
170 /* Completely flush all dynamic entries in forwarding database.*/
171 void br_fdb_flush(struct net_bridge *br)
172 {
173 int i;
174
175 spin_lock_bh(&br->hash_lock);
176 for (i = 0; i < BR_HASH_SIZE; i++) {
177 struct net_bridge_fdb_entry *f;
178 struct hlist_node *h, *n;
179 hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
180 if (!f->is_static)
181 fdb_delete(br, f);
182 }
183 }
184 spin_unlock_bh(&br->hash_lock);
185 }
186
187 /* Flush all entries referring to a specific port.
188 * if do_all is set also flush static entries
189 */
190 void br_fdb_delete_by_port(struct net_bridge *br,
191 const struct net_bridge_port *p,
192 int do_all)
193 {
194 int i;
195
196 spin_lock_bh(&br->hash_lock);
197 for (i = 0; i < BR_HASH_SIZE; i++) {
198 struct hlist_node *h, *g;
199
200 hlist_for_each_safe(h, g, &br->hash[i]) {
201 struct net_bridge_fdb_entry *f
202 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
203 if (f->dst != p)
204 continue;
205
206 if (f->is_static && !do_all)
207 continue;
208 /*
209 * if multiple ports all have the same device address
210 * then when one port is deleted, assign
211 * the local entry to other port
212 */
213 if (f->is_local) {
214 struct net_bridge_port *op;
215 list_for_each_entry(op, &br->port_list, list) {
216 if (op != p &&
217 ether_addr_equal(op->dev->dev_addr,
218 f->addr.addr)) {
219 f->dst = op;
220 goto skip_delete;
221 }
222 }
223 }
224
225 fdb_delete(br, f);
226 skip_delete: ;
227 }
228 }
229 spin_unlock_bh(&br->hash_lock);
230 }
231
232 /* No locking or refcounting, assumes caller has rcu_read_lock */
233 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
234 const unsigned char *addr)
235 {
236 struct hlist_node *h;
237 struct net_bridge_fdb_entry *fdb;
238
239 hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
240 if (ether_addr_equal(fdb->addr.addr, addr)) {
241 if (unlikely(has_expired(br, fdb)))
242 break;
243 return fdb;
244 }
245 }
246
247 return NULL;
248 }
249
250 #if IS_ENABLED(CONFIG_ATM_LANE)
251 /* Interface used by ATM LANE hook to test
252 * if an addr is on some other bridge port */
253 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
254 {
255 struct net_bridge_fdb_entry *fdb;
256 struct net_bridge_port *port;
257 int ret;
258
259 rcu_read_lock();
260 port = br_port_get_rcu(dev);
261 if (!port)
262 ret = 0;
263 else {
264 fdb = __br_fdb_get(port->br, addr);
265 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
266 fdb->dst->state == BR_STATE_FORWARDING;
267 }
268 rcu_read_unlock();
269
270 return ret;
271 }
272 #endif /* CONFIG_ATM_LANE */
273
274 /*
275 * Fill buffer with forwarding table records in
276 * the API format.
277 */
278 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
279 unsigned long maxnum, unsigned long skip)
280 {
281 struct __fdb_entry *fe = buf;
282 int i, num = 0;
283 struct hlist_node *h;
284 struct net_bridge_fdb_entry *f;
285
286 memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
287
288 rcu_read_lock();
289 for (i = 0; i < BR_HASH_SIZE; i++) {
290 hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
291 if (num >= maxnum)
292 goto out;
293
294 if (has_expired(br, f))
295 continue;
296
297 /* ignore pseudo entry for local MAC address */
298 if (!f->dst)
299 continue;
300
301 if (skip) {
302 --skip;
303 continue;
304 }
305
306 /* convert from internal format to API */
307 memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
308
309 /* due to ABI compat need to split into hi/lo */
310 fe->port_no = f->dst->port_no;
311 fe->port_hi = f->dst->port_no >> 8;
312
313 fe->is_local = f->is_local;
314 if (!f->is_static)
315 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
316 ++fe;
317 ++num;
318 }
319 }
320
321 out:
322 rcu_read_unlock();
323
324 return num;
325 }
326
327 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
328 const unsigned char *addr)
329 {
330 struct hlist_node *h;
331 struct net_bridge_fdb_entry *fdb;
332
333 hlist_for_each_entry(fdb, h, head, hlist) {
334 if (ether_addr_equal(fdb->addr.addr, addr))
335 return fdb;
336 }
337 return NULL;
338 }
339
340 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
341 const unsigned char *addr)
342 {
343 struct hlist_node *h;
344 struct net_bridge_fdb_entry *fdb;
345
346 hlist_for_each_entry_rcu(fdb, h, head, hlist) {
347 if (ether_addr_equal(fdb->addr.addr, addr))
348 return fdb;
349 }
350 return NULL;
351 }
352
353 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
354 struct net_bridge_port *source,
355 const unsigned char *addr)
356 {
357 struct net_bridge_fdb_entry *fdb;
358
359 fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
360 if (fdb) {
361 memcpy(fdb->addr.addr, addr, ETH_ALEN);
362 fdb->dst = source;
363 fdb->is_local = 0;
364 fdb->is_static = 0;
365 fdb->updated = fdb->used = jiffies;
366 hlist_add_head_rcu(&fdb->hlist, head);
367 }
368 return fdb;
369 }
370
371 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
372 const unsigned char *addr)
373 {
374 struct hlist_head *head = &br->hash[br_mac_hash(addr)];
375 struct net_bridge_fdb_entry *fdb;
376
377 if (!is_valid_ether_addr(addr))
378 return -EINVAL;
379
380 fdb = fdb_find(head, addr);
381 if (fdb) {
382 /* it is okay to have multiple ports with same
383 * address, just use the first one.
384 */
385 if (fdb->is_local)
386 return 0;
387 br_warn(br, "adding interface %s with same address "
388 "as a received packet\n",
389 source->dev->name);
390 fdb_delete(br, fdb);
391 }
392
393 fdb = fdb_create(head, source, addr);
394 if (!fdb)
395 return -ENOMEM;
396
397 fdb->is_local = fdb->is_static = 1;
398 fdb_notify(br, fdb, RTM_NEWNEIGH);
399 return 0;
400 }
401
402 /* Add entry for local address of interface */
403 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
404 const unsigned char *addr)
405 {
406 int ret;
407
408 spin_lock_bh(&br->hash_lock);
409 ret = fdb_insert(br, source, addr);
410 spin_unlock_bh(&br->hash_lock);
411 return ret;
412 }
413
414 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
415 const unsigned char *addr)
416 {
417 struct hlist_head *head = &br->hash[br_mac_hash(addr)];
418 struct net_bridge_fdb_entry *fdb;
419
420 /* some users want to always flood. */
421 if (hold_time(br) == 0)
422 return;
423
424 /* ignore packets unless we are using this port */
425 if (!(source->state == BR_STATE_LEARNING ||
426 source->state == BR_STATE_FORWARDING))
427 return;
428
429 fdb = fdb_find_rcu(head, addr);
430 if (likely(fdb)) {
431 /* attempt to update an entry for a local interface */
432 if (unlikely(fdb->is_local)) {
433 if (net_ratelimit())
434 br_warn(br, "received packet on %s with "
435 "own address as source address\n",
436 source->dev->name);
437 } else {
438 /* fastpath: update of existing entry */
439 fdb->dst = source;
440 fdb->updated = jiffies;
441 }
442 } else {
443 spin_lock(&br->hash_lock);
444 if (likely(!fdb_find(head, addr))) {
445 fdb = fdb_create(head, source, addr);
446 if (fdb)
447 fdb_notify(br, fdb, RTM_NEWNEIGH);
448 }
449 /* else we lose race and someone else inserts
450 * it first, don't bother updating
451 */
452 spin_unlock(&br->hash_lock);
453 }
454 }
455
456 static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
457 {
458 if (fdb->is_local)
459 return NUD_PERMANENT;
460 else if (fdb->is_static)
461 return NUD_NOARP;
462 else if (has_expired(fdb->dst->br, fdb))
463 return NUD_STALE;
464 else
465 return NUD_REACHABLE;
466 }
467
468 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
469 const struct net_bridge_fdb_entry *fdb,
470 u32 portid, u32 seq, int type, unsigned int flags)
471 {
472 unsigned long now = jiffies;
473 struct nda_cacheinfo ci;
474 struct nlmsghdr *nlh;
475 struct ndmsg *ndm;
476
477 nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
478 if (nlh == NULL)
479 return -EMSGSIZE;
480
481 ndm = nlmsg_data(nlh);
482 ndm->ndm_family = AF_BRIDGE;
483 ndm->ndm_pad1 = 0;
484 ndm->ndm_pad2 = 0;
485 ndm->ndm_flags = 0;
486 ndm->ndm_type = 0;
487 ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
488 ndm->ndm_state = fdb_to_nud(fdb);
489
490 if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
491 goto nla_put_failure;
492 ci.ndm_used = jiffies_to_clock_t(now - fdb->used);
493 ci.ndm_confirmed = 0;
494 ci.ndm_updated = jiffies_to_clock_t(now - fdb->updated);
495 ci.ndm_refcnt = 0;
496 if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
497 goto nla_put_failure;
498 return nlmsg_end(skb, nlh);
499
500 nla_put_failure:
501 nlmsg_cancel(skb, nlh);
502 return -EMSGSIZE;
503 }
504
505 static inline size_t fdb_nlmsg_size(void)
506 {
507 return NLMSG_ALIGN(sizeof(struct ndmsg))
508 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
509 + nla_total_size(sizeof(struct nda_cacheinfo));
510 }
511
512 static void fdb_notify(struct net_bridge *br,
513 const struct net_bridge_fdb_entry *fdb, int type)
514 {
515 struct net *net = dev_net(br->dev);
516 struct sk_buff *skb;
517 int err = -ENOBUFS;
518
519 skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
520 if (skb == NULL)
521 goto errout;
522
523 err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
524 if (err < 0) {
525 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
526 WARN_ON(err == -EMSGSIZE);
527 kfree_skb(skb);
528 goto errout;
529 }
530 rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
531 return;
532 errout:
533 if (err < 0)
534 rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
535 }
536
537 /* Dump information about entries, in response to GETNEIGH */
538 int br_fdb_dump(struct sk_buff *skb,
539 struct netlink_callback *cb,
540 struct net_device *dev,
541 int idx)
542 {
543 struct net_bridge *br = netdev_priv(dev);
544 int i;
545
546 if (!(dev->priv_flags & IFF_EBRIDGE))
547 goto out;
548
549 for (i = 0; i < BR_HASH_SIZE; i++) {
550 struct hlist_node *h;
551 struct net_bridge_fdb_entry *f;
552
553 hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
554 if (idx < cb->args[0])
555 goto skip;
556
557 if (fdb_fill_info(skb, br, f,
558 NETLINK_CB(cb->skb).portid,
559 cb->nlh->nlmsg_seq,
560 RTM_NEWNEIGH,
561 NLM_F_MULTI) < 0)
562 break;
563 skip:
564 ++idx;
565 }
566 }
567
568 out:
569 return idx;
570 }
571
572 /* Update (create or replace) forwarding database entry */
573 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
574 __u16 state, __u16 flags)
575 {
576 struct net_bridge *br = source->br;
577 struct hlist_head *head = &br->hash[br_mac_hash(addr)];
578 struct net_bridge_fdb_entry *fdb;
579
580 fdb = fdb_find(head, addr);
581 if (fdb == NULL) {
582 if (!(flags & NLM_F_CREATE))
583 return -ENOENT;
584
585 fdb = fdb_create(head, source, addr);
586 if (!fdb)
587 return -ENOMEM;
588 fdb_notify(br, fdb, RTM_NEWNEIGH);
589 } else {
590 if (flags & NLM_F_EXCL)
591 return -EEXIST;
592 }
593
594 if (fdb_to_nud(fdb) != state) {
595 if (state & NUD_PERMANENT)
596 fdb->is_local = fdb->is_static = 1;
597 else if (state & NUD_NOARP) {
598 fdb->is_local = 0;
599 fdb->is_static = 1;
600 } else
601 fdb->is_local = fdb->is_static = 0;
602
603 fdb->updated = fdb->used = jiffies;
604 fdb_notify(br, fdb, RTM_NEWNEIGH);
605 }
606
607 return 0;
608 }
609
610 /* Add new permanent fdb entry with RTM_NEWNEIGH */
611 int br_fdb_add(struct ndmsg *ndm, struct net_device *dev,
612 unsigned char *addr, u16 nlh_flags)
613 {
614 struct net_bridge_port *p;
615 int err = 0;
616
617 if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
618 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
619 return -EINVAL;
620 }
621
622 p = br_port_get_rtnl(dev);
623 if (p == NULL) {
624 pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
625 dev->name);
626 return -EINVAL;
627 }
628
629 if (ndm->ndm_flags & NTF_USE) {
630 rcu_read_lock();
631 br_fdb_update(p->br, p, addr);
632 rcu_read_unlock();
633 } else {
634 spin_lock_bh(&p->br->hash_lock);
635 err = fdb_add_entry(p, addr, ndm->ndm_state, nlh_flags);
636 spin_unlock_bh(&p->br->hash_lock);
637 }
638
639 return err;
640 }
641
642 static int fdb_delete_by_addr(struct net_bridge_port *p, u8 *addr)
643 {
644 struct net_bridge *br = p->br;
645 struct hlist_head *head = &br->hash[br_mac_hash(addr)];
646 struct net_bridge_fdb_entry *fdb;
647
648 fdb = fdb_find(head, addr);
649 if (!fdb)
650 return -ENOENT;
651
652 fdb_delete(p->br, fdb);
653 return 0;
654 }
655
656 /* Remove neighbor entry with RTM_DELNEIGH */
657 int br_fdb_delete(struct ndmsg *ndm, struct net_device *dev,
658 unsigned char *addr)
659 {
660 struct net_bridge_port *p;
661 int err;
662
663 p = br_port_get_rtnl(dev);
664 if (p == NULL) {
665 pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
666 dev->name);
667 return -EINVAL;
668 }
669
670 spin_lock_bh(&p->br->hash_lock);
671 err = fdb_delete_by_addr(p, addr);
672 spin_unlock_bh(&p->br->hash_lock);
673
674 return err;
675 }