ext4: check bh in ext4_read_block_bitmap()
[deliverable/linux.git] / net / batman-adv / hard-interface.c
1 /* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
2 *
3 * Marek Lindner, Simon Wunderlich
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of version 2 of the GNU General Public
7 * License as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA
18 */
19
20 #include "main.h"
21 #include "distributed-arp-table.h"
22 #include "hard-interface.h"
23 #include "soft-interface.h"
24 #include "send.h"
25 #include "translation-table.h"
26 #include "routing.h"
27 #include "sysfs.h"
28 #include "originator.h"
29 #include "hash.h"
30 #include "bridge_loop_avoidance.h"
31
32 #include <linux/if_arp.h>
33 #include <linux/if_ether.h>
34
35 void batadv_hardif_free_rcu(struct rcu_head *rcu)
36 {
37 struct batadv_hard_iface *hard_iface;
38
39 hard_iface = container_of(rcu, struct batadv_hard_iface, rcu);
40 dev_put(hard_iface->net_dev);
41 kfree(hard_iface);
42 }
43
44 struct batadv_hard_iface *
45 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
46 {
47 struct batadv_hard_iface *hard_iface;
48
49 rcu_read_lock();
50 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
51 if (hard_iface->net_dev == net_dev &&
52 atomic_inc_not_zero(&hard_iface->refcount))
53 goto out;
54 }
55
56 hard_iface = NULL;
57
58 out:
59 rcu_read_unlock();
60 return hard_iface;
61 }
62
63 /**
64 * batadv_is_on_batman_iface - check if a device is a batman iface descendant
65 * @net_dev: the device to check
66 *
67 * If the user creates any virtual device on top of a batman-adv interface, it
68 * is important to prevent this new interface to be used to create a new mesh
69 * network (this behaviour would lead to a batman-over-batman configuration).
70 * This function recursively checks all the fathers of the device passed as
71 * argument looking for a batman-adv soft interface.
72 *
73 * Returns true if the device is descendant of a batman-adv mesh interface (or
74 * if it is a batman-adv interface itself), false otherwise
75 */
76 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
77 {
78 struct net_device *parent_dev;
79 bool ret;
80
81 /* check if this is a batman-adv mesh interface */
82 if (batadv_softif_is_valid(net_dev))
83 return true;
84
85 /* no more parents..stop recursion */
86 if (net_dev->iflink == net_dev->ifindex)
87 return false;
88
89 /* recurse over the parent device */
90 parent_dev = dev_get_by_index(&init_net, net_dev->iflink);
91 /* if we got a NULL parent_dev there is something broken.. */
92 if (WARN(!parent_dev, "Cannot find parent device"))
93 return false;
94
95 ret = batadv_is_on_batman_iface(parent_dev);
96
97 if (parent_dev)
98 dev_put(parent_dev);
99 return ret;
100 }
101
102 static int batadv_is_valid_iface(const struct net_device *net_dev)
103 {
104 if (net_dev->flags & IFF_LOOPBACK)
105 return 0;
106
107 if (net_dev->type != ARPHRD_ETHER)
108 return 0;
109
110 if (net_dev->addr_len != ETH_ALEN)
111 return 0;
112
113 /* no batman over batman */
114 if (batadv_is_on_batman_iface(net_dev))
115 return 0;
116
117 return 1;
118 }
119
120 static struct batadv_hard_iface *
121 batadv_hardif_get_active(const struct net_device *soft_iface)
122 {
123 struct batadv_hard_iface *hard_iface;
124
125 rcu_read_lock();
126 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
127 if (hard_iface->soft_iface != soft_iface)
128 continue;
129
130 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
131 atomic_inc_not_zero(&hard_iface->refcount))
132 goto out;
133 }
134
135 hard_iface = NULL;
136
137 out:
138 rcu_read_unlock();
139 return hard_iface;
140 }
141
142 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
143 struct batadv_hard_iface *oldif)
144 {
145 struct batadv_vis_packet *vis_packet;
146 struct batadv_hard_iface *primary_if;
147 struct sk_buff *skb;
148
149 primary_if = batadv_primary_if_get_selected(bat_priv);
150 if (!primary_if)
151 goto out;
152
153 batadv_dat_init_own_addr(bat_priv, primary_if);
154
155 skb = bat_priv->vis.my_info->skb_packet;
156 vis_packet = (struct batadv_vis_packet *)skb->data;
157 memcpy(vis_packet->vis_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
158 memcpy(vis_packet->sender_orig,
159 primary_if->net_dev->dev_addr, ETH_ALEN);
160
161 batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
162 out:
163 if (primary_if)
164 batadv_hardif_free_ref(primary_if);
165 }
166
167 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
168 struct batadv_hard_iface *new_hard_iface)
169 {
170 struct batadv_hard_iface *curr_hard_iface;
171
172 ASSERT_RTNL();
173
174 if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
175 new_hard_iface = NULL;
176
177 curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
178 rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
179
180 if (!new_hard_iface)
181 goto out;
182
183 bat_priv->bat_algo_ops->bat_primary_iface_set(new_hard_iface);
184 batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
185
186 out:
187 if (curr_hard_iface)
188 batadv_hardif_free_ref(curr_hard_iface);
189 }
190
191 static bool
192 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
193 {
194 if (hard_iface->net_dev->flags & IFF_UP)
195 return true;
196
197 return false;
198 }
199
200 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
201 {
202 const struct batadv_hard_iface *hard_iface;
203
204 rcu_read_lock();
205 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
206 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
207 (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
208 continue;
209
210 if (hard_iface->net_dev == net_dev)
211 continue;
212
213 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
214 net_dev->dev_addr))
215 continue;
216
217 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
218 net_dev->dev_addr, hard_iface->net_dev->name);
219 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
220 }
221 rcu_read_unlock();
222 }
223
224 int batadv_hardif_min_mtu(struct net_device *soft_iface)
225 {
226 const struct batadv_priv *bat_priv = netdev_priv(soft_iface);
227 const struct batadv_hard_iface *hard_iface;
228 /* allow big frames if all devices are capable to do so
229 * (have MTU > 1500 + BAT_HEADER_LEN)
230 */
231 int min_mtu = ETH_DATA_LEN;
232
233 if (atomic_read(&bat_priv->fragmentation))
234 goto out;
235
236 rcu_read_lock();
237 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
238 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
239 (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
240 continue;
241
242 if (hard_iface->soft_iface != soft_iface)
243 continue;
244
245 min_mtu = min_t(int,
246 hard_iface->net_dev->mtu - BATADV_HEADER_LEN,
247 min_mtu);
248 }
249 rcu_read_unlock();
250 out:
251 return min_mtu;
252 }
253
254 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
255 void batadv_update_min_mtu(struct net_device *soft_iface)
256 {
257 int min_mtu;
258
259 min_mtu = batadv_hardif_min_mtu(soft_iface);
260 if (soft_iface->mtu != min_mtu)
261 soft_iface->mtu = min_mtu;
262 }
263
264 static void
265 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
266 {
267 struct batadv_priv *bat_priv;
268 struct batadv_hard_iface *primary_if = NULL;
269
270 if (hard_iface->if_status != BATADV_IF_INACTIVE)
271 goto out;
272
273 bat_priv = netdev_priv(hard_iface->soft_iface);
274
275 bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
276 hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
277
278 /* the first active interface becomes our primary interface or
279 * the next active interface after the old primary interface was removed
280 */
281 primary_if = batadv_primary_if_get_selected(bat_priv);
282 if (!primary_if)
283 batadv_primary_if_select(bat_priv, hard_iface);
284
285 batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
286 hard_iface->net_dev->name);
287
288 batadv_update_min_mtu(hard_iface->soft_iface);
289
290 out:
291 if (primary_if)
292 batadv_hardif_free_ref(primary_if);
293 }
294
295 static void
296 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
297 {
298 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
299 (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
300 return;
301
302 hard_iface->if_status = BATADV_IF_INACTIVE;
303
304 batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
305 hard_iface->net_dev->name);
306
307 batadv_update_min_mtu(hard_iface->soft_iface);
308 }
309
310 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
311 const char *iface_name)
312 {
313 struct batadv_priv *bat_priv;
314 struct net_device *soft_iface;
315 __be16 ethertype = __constant_htons(ETH_P_BATMAN);
316 int ret;
317
318 if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
319 goto out;
320
321 if (!atomic_inc_not_zero(&hard_iface->refcount))
322 goto out;
323
324 /* hard-interface is part of a bridge */
325 if (hard_iface->net_dev->priv_flags & IFF_BRIDGE_PORT)
326 pr_err("You are about to enable batman-adv on '%s' which already is part of a bridge. Unless you know exactly what you are doing this is probably wrong and won't work the way you think it would.\n",
327 hard_iface->net_dev->name);
328
329 soft_iface = dev_get_by_name(&init_net, iface_name);
330
331 if (!soft_iface) {
332 soft_iface = batadv_softif_create(iface_name);
333
334 if (!soft_iface) {
335 ret = -ENOMEM;
336 goto err;
337 }
338
339 /* dev_get_by_name() increases the reference counter for us */
340 dev_hold(soft_iface);
341 }
342
343 if (!batadv_softif_is_valid(soft_iface)) {
344 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
345 soft_iface->name);
346 ret = -EINVAL;
347 goto err_dev;
348 }
349
350 hard_iface->soft_iface = soft_iface;
351 bat_priv = netdev_priv(hard_iface->soft_iface);
352
353 ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
354 if (ret < 0)
355 goto err_dev;
356
357 hard_iface->if_num = bat_priv->num_ifaces;
358 bat_priv->num_ifaces++;
359 hard_iface->if_status = BATADV_IF_INACTIVE;
360 ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
361 if (ret < 0) {
362 bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
363 bat_priv->num_ifaces--;
364 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
365 goto err_dev;
366 }
367
368 hard_iface->batman_adv_ptype.type = ethertype;
369 hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
370 hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
371 dev_add_pack(&hard_iface->batman_adv_ptype);
372
373 atomic_set(&hard_iface->frag_seqno, 1);
374 batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
375 hard_iface->net_dev->name);
376
377 if (atomic_read(&bat_priv->fragmentation) &&
378 hard_iface->net_dev->mtu < ETH_DATA_LEN + BATADV_HEADER_LEN)
379 batadv_info(hard_iface->soft_iface,
380 "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to %zi would solve the problem.\n",
381 hard_iface->net_dev->name, hard_iface->net_dev->mtu,
382 ETH_DATA_LEN + BATADV_HEADER_LEN);
383
384 if (!atomic_read(&bat_priv->fragmentation) &&
385 hard_iface->net_dev->mtu < ETH_DATA_LEN + BATADV_HEADER_LEN)
386 batadv_info(hard_iface->soft_iface,
387 "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. If you experience problems getting traffic through try increasing the MTU to %zi.\n",
388 hard_iface->net_dev->name, hard_iface->net_dev->mtu,
389 ETH_DATA_LEN + BATADV_HEADER_LEN);
390
391 if (batadv_hardif_is_iface_up(hard_iface))
392 batadv_hardif_activate_interface(hard_iface);
393 else
394 batadv_err(hard_iface->soft_iface,
395 "Not using interface %s (retrying later): interface not active\n",
396 hard_iface->net_dev->name);
397
398 /* begin scheduling originator messages on that interface */
399 batadv_schedule_bat_ogm(hard_iface);
400
401 out:
402 return 0;
403
404 err_dev:
405 dev_put(soft_iface);
406 err:
407 batadv_hardif_free_ref(hard_iface);
408 return ret;
409 }
410
411 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface)
412 {
413 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
414 struct batadv_hard_iface *primary_if = NULL;
415
416 if (hard_iface->if_status == BATADV_IF_ACTIVE)
417 batadv_hardif_deactivate_interface(hard_iface);
418
419 if (hard_iface->if_status != BATADV_IF_INACTIVE)
420 goto out;
421
422 batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
423 hard_iface->net_dev->name);
424 dev_remove_pack(&hard_iface->batman_adv_ptype);
425
426 bat_priv->num_ifaces--;
427 batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
428
429 primary_if = batadv_primary_if_get_selected(bat_priv);
430 if (hard_iface == primary_if) {
431 struct batadv_hard_iface *new_if;
432
433 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
434 batadv_primary_if_select(bat_priv, new_if);
435
436 if (new_if)
437 batadv_hardif_free_ref(new_if);
438 }
439
440 bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
441 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
442
443 /* delete all references to this hard_iface */
444 batadv_purge_orig_ref(bat_priv);
445 batadv_purge_outstanding_packets(bat_priv, hard_iface);
446 dev_put(hard_iface->soft_iface);
447
448 /* nobody uses this interface anymore */
449 if (!bat_priv->num_ifaces)
450 batadv_softif_destroy(hard_iface->soft_iface);
451
452 hard_iface->soft_iface = NULL;
453 batadv_hardif_free_ref(hard_iface);
454
455 out:
456 if (primary_if)
457 batadv_hardif_free_ref(primary_if);
458 }
459
460 static struct batadv_hard_iface *
461 batadv_hardif_add_interface(struct net_device *net_dev)
462 {
463 struct batadv_hard_iface *hard_iface;
464 int ret;
465
466 ASSERT_RTNL();
467
468 ret = batadv_is_valid_iface(net_dev);
469 if (ret != 1)
470 goto out;
471
472 dev_hold(net_dev);
473
474 hard_iface = kmalloc(sizeof(*hard_iface), GFP_ATOMIC);
475 if (!hard_iface)
476 goto release_dev;
477
478 ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
479 if (ret)
480 goto free_if;
481
482 hard_iface->if_num = -1;
483 hard_iface->net_dev = net_dev;
484 hard_iface->soft_iface = NULL;
485 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
486 INIT_LIST_HEAD(&hard_iface->list);
487 /* extra reference for return */
488 atomic_set(&hard_iface->refcount, 2);
489
490 batadv_check_known_mac_addr(hard_iface->net_dev);
491 list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
492
493 /* This can't be called via a bat_priv callback because
494 * we have no bat_priv yet.
495 */
496 atomic_set(&hard_iface->bat_iv.ogm_seqno, 1);
497 hard_iface->bat_iv.ogm_buff = NULL;
498
499 return hard_iface;
500
501 free_if:
502 kfree(hard_iface);
503 release_dev:
504 dev_put(net_dev);
505 out:
506 return NULL;
507 }
508
509 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
510 {
511 ASSERT_RTNL();
512
513 /* first deactivate interface */
514 if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
515 batadv_hardif_disable_interface(hard_iface);
516
517 if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
518 return;
519
520 hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
521 batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
522 batadv_hardif_free_ref(hard_iface);
523 }
524
525 void batadv_hardif_remove_interfaces(void)
526 {
527 struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
528
529 rtnl_lock();
530 list_for_each_entry_safe(hard_iface, hard_iface_tmp,
531 &batadv_hardif_list, list) {
532 list_del_rcu(&hard_iface->list);
533 batadv_hardif_remove_interface(hard_iface);
534 }
535 rtnl_unlock();
536 }
537
538 static int batadv_hard_if_event(struct notifier_block *this,
539 unsigned long event, void *ptr)
540 {
541 struct net_device *net_dev = ptr;
542 struct batadv_hard_iface *hard_iface;
543 struct batadv_hard_iface *primary_if = NULL;
544 struct batadv_priv *bat_priv;
545
546 hard_iface = batadv_hardif_get_by_netdev(net_dev);
547 if (!hard_iface && event == NETDEV_REGISTER)
548 hard_iface = batadv_hardif_add_interface(net_dev);
549
550 if (!hard_iface)
551 goto out;
552
553 switch (event) {
554 case NETDEV_UP:
555 batadv_hardif_activate_interface(hard_iface);
556 break;
557 case NETDEV_GOING_DOWN:
558 case NETDEV_DOWN:
559 batadv_hardif_deactivate_interface(hard_iface);
560 break;
561 case NETDEV_UNREGISTER:
562 list_del_rcu(&hard_iface->list);
563
564 batadv_hardif_remove_interface(hard_iface);
565 break;
566 case NETDEV_CHANGEMTU:
567 if (hard_iface->soft_iface)
568 batadv_update_min_mtu(hard_iface->soft_iface);
569 break;
570 case NETDEV_CHANGEADDR:
571 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
572 goto hardif_put;
573
574 batadv_check_known_mac_addr(hard_iface->net_dev);
575
576 bat_priv = netdev_priv(hard_iface->soft_iface);
577 bat_priv->bat_algo_ops->bat_iface_update_mac(hard_iface);
578
579 primary_if = batadv_primary_if_get_selected(bat_priv);
580 if (!primary_if)
581 goto hardif_put;
582
583 if (hard_iface == primary_if)
584 batadv_primary_if_update_addr(bat_priv, NULL);
585 break;
586 default:
587 break;
588 }
589
590 hardif_put:
591 batadv_hardif_free_ref(hard_iface);
592 out:
593 if (primary_if)
594 batadv_hardif_free_ref(primary_if);
595 return NOTIFY_DONE;
596 }
597
598 /* This function returns true if the interface represented by ifindex is a
599 * 802.11 wireless device
600 */
601 bool batadv_is_wifi_iface(int ifindex)
602 {
603 struct net_device *net_device = NULL;
604 bool ret = false;
605
606 if (ifindex == BATADV_NULL_IFINDEX)
607 goto out;
608
609 net_device = dev_get_by_index(&init_net, ifindex);
610 if (!net_device)
611 goto out;
612
613 #ifdef CONFIG_WIRELESS_EXT
614 /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
615 * check for wireless_handlers != NULL
616 */
617 if (net_device->wireless_handlers)
618 ret = true;
619 else
620 #endif
621 /* cfg80211 drivers have to set ieee80211_ptr */
622 if (net_device->ieee80211_ptr)
623 ret = true;
624 out:
625 if (net_device)
626 dev_put(net_device);
627 return ret;
628 }
629
630 struct notifier_block batadv_hard_if_notifier = {
631 .notifier_call = batadv_hard_if_event,
632 };
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