1 /*
2 * Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
3 *
4 * Marek Lindner, Simon Wunderlich
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of version 2 of the GNU General Public
8 * License as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18 * 02110-1301, USA
19 *
20 */
21
22 #include "main.h"
23 #include "hard-interface.h"
24 #include "soft-interface.h"
25 #include "send.h"
26 #include "translation-table.h"
27 #include "routing.h"
28 #include "bat_sysfs.h"
29 #include "originator.h"
30 #include "hash.h"
31
32 #include <linux/if_arp.h>
33
34
35 static int batman_skb_recv(struct sk_buff *skb,
36 struct net_device *dev,
37 struct packet_type *ptype,
38 struct net_device *orig_dev);
39
hardif_free_rcu(struct rcu_head * rcu)40 void hardif_free_rcu(struct rcu_head *rcu)
41 {
42 struct hard_iface *hard_iface;
43
44 hard_iface = container_of(rcu, struct hard_iface, rcu);
45 dev_put(hard_iface->net_dev);
46 kfree(hard_iface);
47 }
48
hardif_get_by_netdev(const struct net_device * net_dev)49 struct hard_iface *hardif_get_by_netdev(const struct net_device *net_dev)
50 {
51 struct hard_iface *hard_iface;
52
53 rcu_read_lock();
54 list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
55 if (hard_iface->net_dev == net_dev &&
56 atomic_inc_not_zero(&hard_iface->refcount))
57 goto out;
58 }
59
60 hard_iface = NULL;
61
62 out:
63 rcu_read_unlock();
64 return hard_iface;
65 }
66
is_valid_iface(const struct net_device * net_dev)67 static int is_valid_iface(const struct net_device *net_dev)
68 {
69 if (net_dev->flags & IFF_LOOPBACK)
70 return 0;
71
72 if (net_dev->type != ARPHRD_ETHER)
73 return 0;
74
75 if (net_dev->addr_len != ETH_ALEN)
76 return 0;
77
78 /* no batman over batman */
79 if (softif_is_valid(net_dev))
80 return 0;
81
82 /* Device is being bridged */
83 /* if (net_dev->priv_flags & IFF_BRIDGE_PORT)
84 return 0; */
85
86 return 1;
87 }
88
hardif_get_active(const struct net_device * soft_iface)89 static struct hard_iface *hardif_get_active(const struct net_device *soft_iface)
90 {
91 struct hard_iface *hard_iface;
92
93 rcu_read_lock();
94 list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
95 if (hard_iface->soft_iface != soft_iface)
96 continue;
97
98 if (hard_iface->if_status == IF_ACTIVE &&
99 atomic_inc_not_zero(&hard_iface->refcount))
100 goto out;
101 }
102
103 hard_iface = NULL;
104
105 out:
106 rcu_read_unlock();
107 return hard_iface;
108 }
109
primary_if_update_addr(struct bat_priv * bat_priv)110 static void primary_if_update_addr(struct bat_priv *bat_priv)
111 {
112 struct vis_packet *vis_packet;
113 struct hard_iface *primary_if;
114
115 primary_if = primary_if_get_selected(bat_priv);
116 if (!primary_if)
117 goto out;
118
119 vis_packet = (struct vis_packet *)
120 bat_priv->my_vis_info->skb_packet->data;
121 memcpy(vis_packet->vis_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
122 memcpy(vis_packet->sender_orig,
123 primary_if->net_dev->dev_addr, ETH_ALEN);
124
125 out:
126 if (primary_if)
127 hardif_free_ref(primary_if);
128 }
129
primary_if_select(struct bat_priv * bat_priv,struct hard_iface * new_hard_iface)130 static void primary_if_select(struct bat_priv *bat_priv,
131 struct hard_iface *new_hard_iface)
132 {
133 struct hard_iface *curr_hard_iface;
134
135 ASSERT_RTNL();
136
137 if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
138 new_hard_iface = NULL;
139
140 curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
141 rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
142
143 if (curr_hard_iface)
144 hardif_free_ref(curr_hard_iface);
145
146 if (!new_hard_iface)
147 return;
148
149 bat_priv->bat_algo_ops->bat_ogm_init_primary(new_hard_iface);
150 primary_if_update_addr(bat_priv);
151 }
152
hardif_is_iface_up(const struct hard_iface * hard_iface)153 static bool hardif_is_iface_up(const struct hard_iface *hard_iface)
154 {
155 if (hard_iface->net_dev->flags & IFF_UP)
156 return true;
157
158 return false;
159 }
160
check_known_mac_addr(const struct net_device * net_dev)161 static void check_known_mac_addr(const struct net_device *net_dev)
162 {
163 const struct hard_iface *hard_iface;
164
165 rcu_read_lock();
166 list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
167 if ((hard_iface->if_status != IF_ACTIVE) &&
168 (hard_iface->if_status != IF_TO_BE_ACTIVATED))
169 continue;
170
171 if (hard_iface->net_dev == net_dev)
172 continue;
173
174 if (!compare_eth(hard_iface->net_dev->dev_addr,
175 net_dev->dev_addr))
176 continue;
177
178 pr_warning("The newly added mac address (%pM) already exists on: %s\n",
179 net_dev->dev_addr, hard_iface->net_dev->name);
180 pr_warning("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
181 }
182 rcu_read_unlock();
183 }
184
hardif_min_mtu(struct net_device * soft_iface)185 int hardif_min_mtu(struct net_device *soft_iface)
186 {
187 const struct bat_priv *bat_priv = netdev_priv(soft_iface);
188 const struct hard_iface *hard_iface;
189 /* allow big frames if all devices are capable to do so
190 * (have MTU > 1500 + BAT_HEADER_LEN) */
191 int min_mtu = ETH_DATA_LEN;
192
193 if (atomic_read(&bat_priv->fragmentation))
194 goto out;
195
196 rcu_read_lock();
197 list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
198 if ((hard_iface->if_status != IF_ACTIVE) &&
199 (hard_iface->if_status != IF_TO_BE_ACTIVATED))
200 continue;
201
202 if (hard_iface->soft_iface != soft_iface)
203 continue;
204
205 min_mtu = min_t(int, hard_iface->net_dev->mtu - BAT_HEADER_LEN,
206 min_mtu);
207 }
208 rcu_read_unlock();
209 out:
210 return min_mtu;
211 }
212
213 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
update_min_mtu(struct net_device * soft_iface)214 void update_min_mtu(struct net_device *soft_iface)
215 {
216 int min_mtu;
217
218 min_mtu = hardif_min_mtu(soft_iface);
219 if (soft_iface->mtu != min_mtu)
220 soft_iface->mtu = min_mtu;
221 }
222
hardif_activate_interface(struct hard_iface * hard_iface)223 static void hardif_activate_interface(struct hard_iface *hard_iface)
224 {
225 struct bat_priv *bat_priv;
226 struct hard_iface *primary_if = NULL;
227
228 if (hard_iface->if_status != IF_INACTIVE)
229 goto out;
230
231 bat_priv = netdev_priv(hard_iface->soft_iface);
232
233 bat_priv->bat_algo_ops->bat_ogm_update_mac(hard_iface);
234 hard_iface->if_status = IF_TO_BE_ACTIVATED;
235
236 /**
237 * the first active interface becomes our primary interface or
238 * the next active interface after the old primary interface was removed
239 */
240 primary_if = primary_if_get_selected(bat_priv);
241 if (!primary_if)
242 primary_if_select(bat_priv, hard_iface);
243
244 bat_info(hard_iface->soft_iface, "Interface activated: %s\n",
245 hard_iface->net_dev->name);
246
247 update_min_mtu(hard_iface->soft_iface);
248
249 out:
250 if (primary_if)
251 hardif_free_ref(primary_if);
252 }
253
hardif_deactivate_interface(struct hard_iface * hard_iface)254 static void hardif_deactivate_interface(struct hard_iface *hard_iface)
255 {
256 if ((hard_iface->if_status != IF_ACTIVE) &&
257 (hard_iface->if_status != IF_TO_BE_ACTIVATED))
258 return;
259
260 hard_iface->if_status = IF_INACTIVE;
261
262 bat_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
263 hard_iface->net_dev->name);
264
265 update_min_mtu(hard_iface->soft_iface);
266 }
267
hardif_enable_interface(struct hard_iface * hard_iface,const char * iface_name)268 int hardif_enable_interface(struct hard_iface *hard_iface,
269 const char *iface_name)
270 {
271 struct bat_priv *bat_priv;
272 struct net_device *soft_iface;
273 int ret;
274
275 if (hard_iface->if_status != IF_NOT_IN_USE)
276 goto out;
277
278 if (!atomic_inc_not_zero(&hard_iface->refcount))
279 goto out;
280
281 /* hard-interface is part of a bridge */
282 if (hard_iface->net_dev->priv_flags & IFF_BRIDGE_PORT)
283 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",
284 hard_iface->net_dev->name);
285
286 soft_iface = dev_get_by_name(&init_net, iface_name);
287
288 if (!soft_iface) {
289 soft_iface = softif_create(iface_name);
290
291 if (!soft_iface) {
292 ret = -ENOMEM;
293 goto err;
294 }
295
296 /* dev_get_by_name() increases the reference counter for us */
297 dev_hold(soft_iface);
298 }
299
300 if (!softif_is_valid(soft_iface)) {
301 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
302 soft_iface->name);
303 dev_put(soft_iface);
304 ret = -EINVAL;
305 goto err;
306 }
307
308 hard_iface->soft_iface = soft_iface;
309 bat_priv = netdev_priv(hard_iface->soft_iface);
310
311 bat_priv->bat_algo_ops->bat_ogm_init(hard_iface);
312
313 if (!hard_iface->packet_buff) {
314 bat_err(hard_iface->soft_iface,
315 "Can't add interface packet (%s): out of memory\n",
316 hard_iface->net_dev->name);
317 ret = -ENOMEM;
318 goto err;
319 }
320
321 hard_iface->if_num = bat_priv->num_ifaces;
322 bat_priv->num_ifaces++;
323 hard_iface->if_status = IF_INACTIVE;
324 orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
325
326 hard_iface->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
327 hard_iface->batman_adv_ptype.func = batman_skb_recv;
328 hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
329 dev_add_pack(&hard_iface->batman_adv_ptype);
330
331 atomic_set(&hard_iface->seqno, 1);
332 atomic_set(&hard_iface->frag_seqno, 1);
333 bat_info(hard_iface->soft_iface, "Adding interface: %s\n",
334 hard_iface->net_dev->name);
335
336 if (atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
337 ETH_DATA_LEN + BAT_HEADER_LEN)
338 bat_info(hard_iface->soft_iface,
339 "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",
340 hard_iface->net_dev->name, hard_iface->net_dev->mtu,
341 ETH_DATA_LEN + BAT_HEADER_LEN);
342
343 if (!atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
344 ETH_DATA_LEN + BAT_HEADER_LEN)
345 bat_info(hard_iface->soft_iface,
346 "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",
347 hard_iface->net_dev->name, hard_iface->net_dev->mtu,
348 ETH_DATA_LEN + BAT_HEADER_LEN);
349
350 if (hardif_is_iface_up(hard_iface))
351 hardif_activate_interface(hard_iface);
352 else
353 bat_err(hard_iface->soft_iface,
354 "Not using interface %s (retrying later): interface not active\n",
355 hard_iface->net_dev->name);
356
357 /* begin scheduling originator messages on that interface */
358 schedule_bat_ogm(hard_iface);
359
360 out:
361 return 0;
362
363 err:
364 hardif_free_ref(hard_iface);
365 return ret;
366 }
367
hardif_disable_interface(struct hard_iface * hard_iface)368 void hardif_disable_interface(struct hard_iface *hard_iface)
369 {
370 struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
371 struct hard_iface *primary_if = NULL;
372
373 if (hard_iface->if_status == IF_ACTIVE)
374 hardif_deactivate_interface(hard_iface);
375
376 if (hard_iface->if_status != IF_INACTIVE)
377 goto out;
378
379 bat_info(hard_iface->soft_iface, "Removing interface: %s\n",
380 hard_iface->net_dev->name);
381 dev_remove_pack(&hard_iface->batman_adv_ptype);
382
383 bat_priv->num_ifaces--;
384 orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
385
386 primary_if = primary_if_get_selected(bat_priv);
387 if (hard_iface == primary_if) {
388 struct hard_iface *new_if;
389
390 new_if = hardif_get_active(hard_iface->soft_iface);
391 primary_if_select(bat_priv, new_if);
392
393 if (new_if)
394 hardif_free_ref(new_if);
395 }
396
397 kfree(hard_iface->packet_buff);
398 hard_iface->packet_buff = NULL;
399 hard_iface->if_status = IF_NOT_IN_USE;
400
401 /* delete all references to this hard_iface */
402 purge_orig_ref(bat_priv);
403 purge_outstanding_packets(bat_priv, hard_iface);
404 dev_put(hard_iface->soft_iface);
405
406 /* nobody uses this interface anymore */
407 if (!bat_priv->num_ifaces)
408 softif_destroy(hard_iface->soft_iface);
409
410 hard_iface->soft_iface = NULL;
411 hardif_free_ref(hard_iface);
412
413 out:
414 if (primary_if)
415 hardif_free_ref(primary_if);
416 }
417
hardif_add_interface(struct net_device * net_dev)418 static struct hard_iface *hardif_add_interface(struct net_device *net_dev)
419 {
420 struct hard_iface *hard_iface;
421 int ret;
422
423 ASSERT_RTNL();
424
425 ret = is_valid_iface(net_dev);
426 if (ret != 1)
427 goto out;
428
429 dev_hold(net_dev);
430
431 hard_iface = kmalloc(sizeof(*hard_iface), GFP_ATOMIC);
432 if (!hard_iface)
433 goto release_dev;
434
435 ret = sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
436 if (ret)
437 goto free_if;
438
439 hard_iface->if_num = -1;
440 hard_iface->net_dev = net_dev;
441 hard_iface->soft_iface = NULL;
442 hard_iface->if_status = IF_NOT_IN_USE;
443 INIT_LIST_HEAD(&hard_iface->list);
444 /* extra reference for return */
445 atomic_set(&hard_iface->refcount, 2);
446
447 check_known_mac_addr(hard_iface->net_dev);
448 list_add_tail_rcu(&hard_iface->list, &hardif_list);
449
450 return hard_iface;
451
452 free_if:
453 kfree(hard_iface);
454 release_dev:
455 dev_put(net_dev);
456 out:
457 return NULL;
458 }
459
hardif_remove_interface(struct hard_iface * hard_iface)460 static void hardif_remove_interface(struct hard_iface *hard_iface)
461 {
462 ASSERT_RTNL();
463
464 /* first deactivate interface */
465 if (hard_iface->if_status != IF_NOT_IN_USE)
466 hardif_disable_interface(hard_iface);
467
468 if (hard_iface->if_status != IF_NOT_IN_USE)
469 return;
470
471 hard_iface->if_status = IF_TO_BE_REMOVED;
472 sysfs_del_hardif(&hard_iface->hardif_obj);
473 hardif_free_ref(hard_iface);
474 }
475
hardif_remove_interfaces(void)476 void hardif_remove_interfaces(void)
477 {
478 struct hard_iface *hard_iface, *hard_iface_tmp;
479
480 rtnl_lock();
481 list_for_each_entry_safe(hard_iface, hard_iface_tmp,
482 &hardif_list, list) {
483 list_del_rcu(&hard_iface->list);
484 hardif_remove_interface(hard_iface);
485 }
486 rtnl_unlock();
487 }
488
hard_if_event(struct notifier_block * this,unsigned long event,void * ptr)489 static int hard_if_event(struct notifier_block *this,
490 unsigned long event, void *ptr)
491 {
492 struct net_device *net_dev = ptr;
493 struct hard_iface *hard_iface = hardif_get_by_netdev(net_dev);
494 struct hard_iface *primary_if = NULL;
495 struct bat_priv *bat_priv;
496
497 if (!hard_iface && event == NETDEV_REGISTER)
498 hard_iface = hardif_add_interface(net_dev);
499
500 if (!hard_iface)
501 goto out;
502
503 switch (event) {
504 case NETDEV_UP:
505 hardif_activate_interface(hard_iface);
506 break;
507 case NETDEV_GOING_DOWN:
508 case NETDEV_DOWN:
509 hardif_deactivate_interface(hard_iface);
510 break;
511 case NETDEV_UNREGISTER:
512 list_del_rcu(&hard_iface->list);
513
514 hardif_remove_interface(hard_iface);
515 break;
516 case NETDEV_CHANGEMTU:
517 if (hard_iface->soft_iface)
518 update_min_mtu(hard_iface->soft_iface);
519 break;
520 case NETDEV_CHANGEADDR:
521 if (hard_iface->if_status == IF_NOT_IN_USE)
522 goto hardif_put;
523
524 check_known_mac_addr(hard_iface->net_dev);
525
526 bat_priv = netdev_priv(hard_iface->soft_iface);
527 bat_priv->bat_algo_ops->bat_ogm_update_mac(hard_iface);
528
529 primary_if = primary_if_get_selected(bat_priv);
530 if (!primary_if)
531 goto hardif_put;
532
533 if (hard_iface == primary_if)
534 primary_if_update_addr(bat_priv);
535 break;
536 default:
537 break;
538 }
539
540 hardif_put:
541 hardif_free_ref(hard_iface);
542 out:
543 if (primary_if)
544 hardif_free_ref(primary_if);
545 return NOTIFY_DONE;
546 }
547
548 /* incoming packets with the batman ethertype received on any active hard
549 * interface */
batman_skb_recv(struct sk_buff * skb,struct net_device * dev,struct packet_type * ptype,struct net_device * orig_dev)550 static int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
551 struct packet_type *ptype,
552 struct net_device *orig_dev)
553 {
554 struct bat_priv *bat_priv;
555 struct batman_ogm_packet *batman_ogm_packet;
556 struct hard_iface *hard_iface;
557 int ret;
558
559 hard_iface = container_of(ptype, struct hard_iface, batman_adv_ptype);
560 skb = skb_share_check(skb, GFP_ATOMIC);
561
562 /* skb was released by skb_share_check() */
563 if (!skb)
564 goto err_out;
565
566 /* packet should hold at least type and version */
567 if (unlikely(!pskb_may_pull(skb, 2)))
568 goto err_free;
569
570 /* expect a valid ethernet header here. */
571 if (unlikely(skb->mac_len != sizeof(struct ethhdr) ||
572 !skb_mac_header(skb)))
573 goto err_free;
574
575 if (!hard_iface->soft_iface)
576 goto err_free;
577
578 bat_priv = netdev_priv(hard_iface->soft_iface);
579
580 if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
581 goto err_free;
582
583 /* discard frames on not active interfaces */
584 if (hard_iface->if_status != IF_ACTIVE)
585 goto err_free;
586
587 batman_ogm_packet = (struct batman_ogm_packet *)skb->data;
588
589 if (batman_ogm_packet->header.version != COMPAT_VERSION) {
590 bat_dbg(DBG_BATMAN, bat_priv,
591 "Drop packet: incompatible batman version (%i)\n",
592 batman_ogm_packet->header.version);
593 goto err_free;
594 }
595
596 /* all receive handlers return whether they received or reused
597 * the supplied skb. if not, we have to free the skb. */
598
599 switch (batman_ogm_packet->header.packet_type) {
600 /* batman originator packet */
601 case BAT_OGM:
602 ret = recv_bat_ogm_packet(skb, hard_iface);
603 break;
604
605 /* batman icmp packet */
606 case BAT_ICMP:
607 ret = recv_icmp_packet(skb, hard_iface);
608 break;
609
610 /* unicast packet */
611 case BAT_UNICAST:
612 ret = recv_unicast_packet(skb, hard_iface);
613 break;
614
615 /* fragmented unicast packet */
616 case BAT_UNICAST_FRAG:
617 ret = recv_ucast_frag_packet(skb, hard_iface);
618 break;
619
620 /* broadcast packet */
621 case BAT_BCAST:
622 ret = recv_bcast_packet(skb, hard_iface);
623 break;
624
625 /* vis packet */
626 case BAT_VIS:
627 ret = recv_vis_packet(skb, hard_iface);
628 break;
629 /* Translation table query (request or response) */
630 case BAT_TT_QUERY:
631 ret = recv_tt_query(skb, hard_iface);
632 break;
633 /* Roaming advertisement */
634 case BAT_ROAM_ADV:
635 ret = recv_roam_adv(skb, hard_iface);
636 break;
637 default:
638 ret = NET_RX_DROP;
639 }
640
641 if (ret == NET_RX_DROP)
642 kfree_skb(skb);
643
644 /* return NET_RX_SUCCESS in any case as we
645 * most probably dropped the packet for
646 * routing-logical reasons. */
647
648 return NET_RX_SUCCESS;
649
650 err_free:
651 kfree_skb(skb);
652 err_out:
653 return NET_RX_DROP;
654 }
655
656 /* This function returns true if the interface represented by ifindex is a
657 * 802.11 wireless device */
is_wifi_iface(int ifindex)658 bool is_wifi_iface(int ifindex)
659 {
660 struct net_device *net_device = NULL;
661 bool ret = false;
662
663 if (ifindex == NULL_IFINDEX)
664 goto out;
665
666 net_device = dev_get_by_index(&init_net, ifindex);
667 if (!net_device)
668 goto out;
669
670 #ifdef CONFIG_WIRELESS_EXT
671 /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
672 * check for wireless_handlers != NULL */
673 if (net_device->wireless_handlers)
674 ret = true;
675 else
676 #endif
677 /* cfg80211 drivers have to set ieee80211_ptr */
678 if (net_device->ieee80211_ptr)
679 ret = true;
680 out:
681 if (net_device)
682 dev_put(net_device);
683 return ret;
684 }
685
686 struct notifier_block hard_if_notifier = {
687 .notifier_call = hard_if_event,
688 };
689