1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) B.A.T.M.A.N. contributors:
3 *
4 * Marek Lindner, Simon Wunderlich
5 */
6
7 #include "hard-interface.h"
8 #include "main.h"
9
10 #include <linux/atomic.h>
11 #include <linux/byteorder/generic.h>
12 #include <linux/compiler.h>
13 #include <linux/container_of.h>
14 #include <linux/errno.h>
15 #include <linux/gfp.h>
16 #include <linux/if.h>
17 #include <linux/if_arp.h>
18 #include <linux/if_ether.h>
19 #include <linux/kref.h>
20 #include <linux/limits.h>
21 #include <linux/list.h>
22 #include <linux/minmax.h>
23 #include <linux/mutex.h>
24 #include <linux/netdevice.h>
25 #include <linux/printk.h>
26 #include <linux/rculist.h>
27 #include <linux/rtnetlink.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <net/net_namespace.h>
31 #include <net/rtnetlink.h>
32 #include <uapi/linux/batadv_packet.h>
33
34 #include "bat_v.h"
35 #include "bridge_loop_avoidance.h"
36 #include "distributed-arp-table.h"
37 #include "gateway_client.h"
38 #include "log.h"
39 #include "originator.h"
40 #include "send.h"
41 #include "soft-interface.h"
42 #include "translation-table.h"
43
44 /**
45 * batadv_hardif_release() - release hard interface from lists and queue for
46 * free after rcu grace period
47 * @ref: kref pointer of the hard interface
48 */
49 void batadv_hardif_release(struct kref *ref)
50 {
51 struct batadv_hard_iface *hard_iface;
52
53 hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
54 dev_put(hard_iface->net_dev);
55
56 kfree_rcu(hard_iface, rcu);
57 }
58
59 /**
60 * batadv_hardif_get_by_netdev() - Get hard interface object of a net_device
61 * @net_dev: net_device to search for
62 *
63 * Return: batadv_hard_iface of net_dev (with increased refcnt), NULL on errors
64 */
65 struct batadv_hard_iface *
66 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
67 {
68 struct batadv_hard_iface *hard_iface;
69
70 rcu_read_lock();
71 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
72 if (hard_iface->net_dev == net_dev &&
73 kref_get_unless_zero(&hard_iface->refcount))
74 goto out;
75 }
76
77 hard_iface = NULL;
78
79 out:
80 rcu_read_unlock();
81 return hard_iface;
82 }
83
84 /**
85 * batadv_getlink_net() - return link net namespace (of use fallback)
86 * @netdev: net_device to check
87 * @fallback_net: return in case get_link_net is not available for @netdev
88 *
89 * Return: result of rtnl_link_ops->get_link_net or @fallback_net
90 */
91 static struct net *batadv_getlink_net(const struct net_device *netdev,
92 struct net *fallback_net)
93 {
94 if (!netdev->rtnl_link_ops)
95 return fallback_net;
96
97 if (!netdev->rtnl_link_ops->get_link_net)
98 return fallback_net;
99
100 return netdev->rtnl_link_ops->get_link_net(netdev);
101 }
102
103 /**
104 * batadv_mutual_parents() - check if two devices are each others parent
105 * @dev1: 1st net dev
106 * @net1: 1st devices netns
107 * @dev2: 2nd net dev
108 * @net2: 2nd devices netns
109 *
110 * veth devices come in pairs and each is the parent of the other!
111 *
112 * Return: true if the devices are each others parent, otherwise false
113 */
114 static bool batadv_mutual_parents(const struct net_device *dev1,
115 struct net *net1,
116 const struct net_device *dev2,
117 struct net *net2)
118 {
119 int dev1_parent_iflink = dev_get_iflink(dev1);
120 int dev2_parent_iflink = dev_get_iflink(dev2);
121 const struct net *dev1_parent_net;
122 const struct net *dev2_parent_net;
123
124 dev1_parent_net = batadv_getlink_net(dev1, net1);
125 dev2_parent_net = batadv_getlink_net(dev2, net2);
126
127 if (!dev1_parent_iflink || !dev2_parent_iflink)
128 return false;
129
130 return (dev1_parent_iflink == dev2->ifindex) &&
131 (dev2_parent_iflink == dev1->ifindex) &&
132 net_eq(dev1_parent_net, net2) &&
133 net_eq(dev2_parent_net, net1);
134 }
135
136 /**
137 * batadv_is_on_batman_iface() - check if a device is a batman iface descendant
138 * @net_dev: the device to check
139 *
140 * If the user creates any virtual device on top of a batman-adv interface, it
141 * is important to prevent this new interface from being used to create a new
142 * mesh network (this behaviour would lead to a batman-over-batman
143 * configuration). This function recursively checks all the fathers of the
144 * device passed as argument looking for a batman-adv soft interface.
145 *
146 * Return: true if the device is descendant of a batman-adv mesh interface (or
147 * if it is a batman-adv interface itself), false otherwise
148 */
149 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
150 {
151 struct net *net = dev_net(net_dev);
152 struct net_device *parent_dev;
153 struct net *parent_net;
154 int iflink;
155 bool ret;
156
157 /* check if this is a batman-adv mesh interface */
158 if (batadv_softif_is_valid(net_dev))
159 return true;
160
161 iflink = dev_get_iflink(net_dev);
162 if (iflink == 0)
163 return false;
164
165 parent_net = batadv_getlink_net(net_dev, net);
166
167 /* iflink to itself, most likely physical device */
168 if (net == parent_net && iflink == net_dev->ifindex)
169 return false;
170
171 /* recurse over the parent device */
172 parent_dev = __dev_get_by_index((struct net *)parent_net, iflink);
173 if (!parent_dev) {
174 pr_warn("Cannot find parent device. Skipping batadv-on-batadv check for %s\n",
175 net_dev->name);
176 return false;
177 }
178
179 if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
180 return false;
181
182 ret = batadv_is_on_batman_iface(parent_dev);
183
184 return ret;
185 }
186
187 static bool batadv_is_valid_iface(const struct net_device *net_dev)
188 {
189 if (net_dev->flags & IFF_LOOPBACK)
190 return false;
191
192 if (net_dev->type != ARPHRD_ETHER)
193 return false;
194
195 if (net_dev->addr_len != ETH_ALEN)
196 return false;
197
198 /* no batman over batman */
199 if (batadv_is_on_batman_iface(net_dev))
200 return false;
201
202 return true;
203 }
204
205 /**
206 * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
207 * interface on top of another 'real' interface
208 * @netdev: the device to check
209 *
210 * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
211 * instead of this.
212 *
213 * Return: the 'real' net device or the original net device and NULL in case
214 * of an error.
215 */
216 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
217 {
218 struct batadv_hard_iface *hard_iface = NULL;
219 struct net_device *real_netdev = NULL;
220 struct net *real_net;
221 struct net *net;
222 int iflink;
223
224 ASSERT_RTNL();
225
226 if (!netdev)
227 return NULL;
228
229 iflink = dev_get_iflink(netdev);
230 if (iflink == 0) {
231 dev_hold(netdev);
232 return netdev;
233 }
234
235 hard_iface = batadv_hardif_get_by_netdev(netdev);
236 if (!hard_iface || !hard_iface->soft_iface)
237 goto out;
238
239 net = dev_net(hard_iface->soft_iface);
240 real_net = batadv_getlink_net(netdev, net);
241
242 /* iflink to itself, most likely physical device */
243 if (net == real_net && netdev->ifindex == iflink) {
244 real_netdev = netdev;
245 dev_hold(real_netdev);
246 goto out;
247 }
248
249 real_netdev = dev_get_by_index(real_net, iflink);
250
251 out:
252 batadv_hardif_put(hard_iface);
253 return real_netdev;
254 }
255
256 /**
257 * batadv_get_real_netdev() - check if the given net_device struct is a virtual
258 * interface on top of another 'real' interface
259 * @net_device: the device to check
260 *
261 * Return: the 'real' net device or the original net device and NULL in case
262 * of an error.
263 */
264 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
265 {
266 struct net_device *real_netdev;
267
268 rtnl_lock();
269 real_netdev = batadv_get_real_netdevice(net_device);
270 rtnl_unlock();
271
272 return real_netdev;
273 }
274
275 /**
276 * batadv_is_wext_netdev() - check if the given net_device struct is a
277 * wext wifi interface
278 * @net_device: the device to check
279 *
280 * Return: true if the net device is a wext wireless device, false
281 * otherwise.
282 */
283 static bool batadv_is_wext_netdev(struct net_device *net_device)
284 {
285 if (!net_device)
286 return false;
287
288 #ifdef CONFIG_WIRELESS_EXT
289 /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
290 * check for wireless_handlers != NULL
291 */
292 if (net_device->wireless_handlers)
293 return true;
294 #endif
295
296 return false;
297 }
298
299 /**
300 * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
301 * cfg80211 wifi interface
302 * @net_device: the device to check
303 *
304 * Return: true if the net device is a cfg80211 wireless device, false
305 * otherwise.
306 */
307 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
308 {
309 if (!net_device)
310 return false;
311
312 #if IS_ENABLED(CONFIG_CFG80211)
313 /* cfg80211 drivers have to set ieee80211_ptr */
314 if (net_device->ieee80211_ptr)
315 return true;
316 #endif
317
318 return false;
319 }
320
321 /**
322 * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
323 * @net_device: the device to check
324 *
325 * Return: batadv_hard_iface_wifi_flags flags of the device
326 */
327 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
328 {
329 u32 wifi_flags = 0;
330 struct net_device *real_netdev;
331
332 if (batadv_is_wext_netdev(net_device))
333 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
334
335 if (batadv_is_cfg80211_netdev(net_device))
336 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
337
338 real_netdev = batadv_get_real_netdevice(net_device);
339 if (!real_netdev)
340 return wifi_flags;
341
342 if (real_netdev == net_device)
343 goto out;
344
345 if (batadv_is_wext_netdev(real_netdev))
346 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
347
348 if (batadv_is_cfg80211_netdev(real_netdev))
349 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
350
351 out:
352 dev_put(real_netdev);
353 return wifi_flags;
354 }
355
356 /**
357 * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
358 * interface
359 * @hard_iface: the device to check
360 *
361 * Return: true if the net device is a cfg80211 wireless device, false
362 * otherwise.
363 */
364 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
365 {
366 u32 allowed_flags = 0;
367
368 allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
369 allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
370
371 return !!(hard_iface->wifi_flags & allowed_flags);
372 }
373
374 /**
375 * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
376 * @hard_iface: the device to check
377 *
378 * Return: true if the net device is a 802.11 wireless device, false otherwise.
379 */
380 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
381 {
382 if (!hard_iface)
383 return false;
384
385 return hard_iface->wifi_flags != 0;
386 }
387
388 /**
389 * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
390 * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
391 * @orig_addr: the originator of this packet
392 * @orig_neigh: originator address of the forwarder we just got the packet from
393 * (NULL if we originated)
394 *
395 * Checks whether a packet needs to be (re)broadcasted on the given interface.
396 *
397 * Return:
398 * BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
399 * BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
400 * BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
401 * BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
402 */
403 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
404 u8 *orig_addr, u8 *orig_neigh)
405 {
406 struct batadv_hardif_neigh_node *hardif_neigh;
407 struct hlist_node *first;
408 int ret = BATADV_HARDIF_BCAST_OK;
409
410 rcu_read_lock();
411
412 /* 0 neighbors -> no (re)broadcast */
413 first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
414 if (!first) {
415 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
416 goto out;
417 }
418
419 /* >1 neighbors -> (re)broadcast */
420 if (rcu_dereference(hlist_next_rcu(first)))
421 goto out;
422
423 hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
424 list);
425
426 /* 1 neighbor, is the originator -> no rebroadcast */
427 if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
428 ret = BATADV_HARDIF_BCAST_DUPORIG;
429 /* 1 neighbor, is the one we received from -> no rebroadcast */
430 } else if (orig_neigh &&
431 batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
432 ret = BATADV_HARDIF_BCAST_DUPFWD;
433 }
434
435 out:
436 rcu_read_unlock();
437 return ret;
438 }
439
440 static struct batadv_hard_iface *
441 batadv_hardif_get_active(const struct net_device *soft_iface)
442 {
443 struct batadv_hard_iface *hard_iface;
444
445 rcu_read_lock();
446 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
447 if (hard_iface->soft_iface != soft_iface)
448 continue;
449
450 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
451 kref_get_unless_zero(&hard_iface->refcount))
452 goto out;
453 }
454
455 hard_iface = NULL;
456
457 out:
458 rcu_read_unlock();
459 return hard_iface;
460 }
461
462 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
463 struct batadv_hard_iface *oldif)
464 {
465 struct batadv_hard_iface *primary_if;
466
467 primary_if = batadv_primary_if_get_selected(bat_priv);
468 if (!primary_if)
469 goto out;
470
471 batadv_dat_init_own_addr(bat_priv, primary_if);
472 batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
473 out:
474 batadv_hardif_put(primary_if);
475 }
476
477 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
478 struct batadv_hard_iface *new_hard_iface)
479 {
480 struct batadv_hard_iface *curr_hard_iface;
481
482 ASSERT_RTNL();
483
484 if (new_hard_iface)
485 kref_get(&new_hard_iface->refcount);
486
487 curr_hard_iface = rcu_replace_pointer(bat_priv->primary_if,
488 new_hard_iface, 1);
489
490 if (!new_hard_iface)
491 goto out;
492
493 bat_priv->algo_ops->iface.primary_set(new_hard_iface);
494 batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
495
496 out:
497 batadv_hardif_put(curr_hard_iface);
498 }
499
500 static bool
501 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
502 {
503 if (hard_iface->net_dev->flags & IFF_UP)
504 return true;
505
506 return false;
507 }
508
509 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
510 {
511 const struct batadv_hard_iface *hard_iface;
512
513 rcu_read_lock();
514 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
515 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
516 hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
517 continue;
518
519 if (hard_iface->net_dev == net_dev)
520 continue;
521
522 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
523 net_dev->dev_addr))
524 continue;
525
526 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
527 net_dev->dev_addr, hard_iface->net_dev->name);
528 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
529 }
530 rcu_read_unlock();
531 }
532
533 /**
534 * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
535 * @soft_iface: netdev struct of the mesh interface
536 */
537 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
538 {
539 const struct batadv_hard_iface *hard_iface;
540 unsigned short lower_header_len = ETH_HLEN;
541 unsigned short lower_headroom = 0;
542 unsigned short lower_tailroom = 0;
543 unsigned short needed_headroom;
544
545 rcu_read_lock();
546 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
547 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
548 continue;
549
550 if (hard_iface->soft_iface != soft_iface)
551 continue;
552
553 lower_header_len = max_t(unsigned short, lower_header_len,
554 hard_iface->net_dev->hard_header_len);
555
556 lower_headroom = max_t(unsigned short, lower_headroom,
557 hard_iface->net_dev->needed_headroom);
558
559 lower_tailroom = max_t(unsigned short, lower_tailroom,
560 hard_iface->net_dev->needed_tailroom);
561 }
562 rcu_read_unlock();
563
564 needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
565 needed_headroom += batadv_max_header_len();
566
567 /* fragmentation headers don't strip the unicast/... header */
568 needed_headroom += sizeof(struct batadv_frag_packet);
569
570 soft_iface->needed_headroom = needed_headroom;
571 soft_iface->needed_tailroom = lower_tailroom;
572 }
573
574 /**
575 * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
576 * @soft_iface: netdev struct of the soft interface
577 *
578 * Return: MTU for the soft-interface (limited by the minimal MTU of all active
579 * slave interfaces)
580 */
581 int batadv_hardif_min_mtu(struct net_device *soft_iface)
582 {
583 struct batadv_priv *bat_priv = netdev_priv(soft_iface);
584 const struct batadv_hard_iface *hard_iface;
585 int min_mtu = INT_MAX;
586
587 rcu_read_lock();
588 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
589 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
590 hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
591 continue;
592
593 if (hard_iface->soft_iface != soft_iface)
594 continue;
595
596 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
597 }
598 rcu_read_unlock();
599
600 if (atomic_read(&bat_priv->fragmentation) == 0)
601 goto out;
602
603 /* with fragmentation enabled the maximum size of internally generated
604 * packets such as translation table exchanges or tvlv containers, etc
605 * has to be calculated
606 */
607 min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
608 min_mtu -= sizeof(struct batadv_frag_packet);
609 min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
610
611 out:
612 /* report to the other components the maximum amount of bytes that
613 * batman-adv can send over the wire (without considering the payload
614 * overhead). For example, this value is used by TT to compute the
615 * maximum local table size
616 */
617 atomic_set(&bat_priv->packet_size_max, min_mtu);
618
619 /* the real soft-interface MTU is computed by removing the payload
620 * overhead from the maximum amount of bytes that was just computed.
621 *
622 * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
623 */
624 return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
625 }
626
627 /**
628 * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
629 * MTU appeared
630 * @soft_iface: netdev struct of the soft interface
631 */
632 void batadv_update_min_mtu(struct net_device *soft_iface)
633 {
634 struct batadv_priv *bat_priv = netdev_priv(soft_iface);
635 int limit_mtu;
636 int mtu;
637
638 mtu = batadv_hardif_min_mtu(soft_iface);
639
640 if (bat_priv->mtu_set_by_user)
641 limit_mtu = bat_priv->mtu_set_by_user;
642 else
643 limit_mtu = ETH_DATA_LEN;
644
645 mtu = min(mtu, limit_mtu);
646 dev_set_mtu(soft_iface, mtu);
647
648 /* Check if the local translate table should be cleaned up to match a
649 * new (and smaller) MTU.
650 */
651 batadv_tt_local_resize_to_mtu(soft_iface);
652 }
653
654 static void
655 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
656 {
657 struct batadv_priv *bat_priv;
658 struct batadv_hard_iface *primary_if = NULL;
659
660 if (hard_iface->if_status != BATADV_IF_INACTIVE)
661 goto out;
662
663 bat_priv = netdev_priv(hard_iface->soft_iface);
664
665 bat_priv->algo_ops->iface.update_mac(hard_iface);
666 hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
667
668 /* the first active interface becomes our primary interface or
669 * the next active interface after the old primary interface was removed
670 */
671 primary_if = batadv_primary_if_get_selected(bat_priv);
672 if (!primary_if)
673 batadv_primary_if_select(bat_priv, hard_iface);
674
675 batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
676 hard_iface->net_dev->name);
677
678 batadv_update_min_mtu(hard_iface->soft_iface);
679
680 if (bat_priv->algo_ops->iface.activate)
681 bat_priv->algo_ops->iface.activate(hard_iface);
682
683 out:
684 batadv_hardif_put(primary_if);
685 }
686
687 static void
688 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
689 {
690 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
691 hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
692 return;
693
694 hard_iface->if_status = BATADV_IF_INACTIVE;
695
696 batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
697 hard_iface->net_dev->name);
698
699 batadv_update_min_mtu(hard_iface->soft_iface);
700 }
701
702 /**
703 * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
704 * @hard_iface: hard interface to add to soft interface
705 * @soft_iface: netdev struct of the mesh interface
706 *
707 * Return: 0 on success or negative error number in case of failure
708 */
709 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
710 struct net_device *soft_iface)
711 {
712 struct batadv_priv *bat_priv;
713 __be16 ethertype = htons(ETH_P_BATMAN);
714 int max_header_len = batadv_max_header_len();
715 unsigned int required_mtu;
716 unsigned int hardif_mtu;
717 int ret;
718
719 hardif_mtu = READ_ONCE(hard_iface->net_dev->mtu);
720 required_mtu = READ_ONCE(soft_iface->mtu) + max_header_len;
721
722 if (hardif_mtu < ETH_MIN_MTU + max_header_len)
723 return -EINVAL;
724
725 if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
726 goto out;
727
728 kref_get(&hard_iface->refcount);
729
730 dev_hold(soft_iface);
731 hard_iface->soft_iface = soft_iface;
732 bat_priv = netdev_priv(hard_iface->soft_iface);
733
734 ret = netdev_master_upper_dev_link(hard_iface->net_dev,
735 soft_iface, NULL, NULL, NULL);
736 if (ret)
737 goto err_dev;
738
739 ret = bat_priv->algo_ops->iface.enable(hard_iface);
740 if (ret < 0)
741 goto err_upper;
742
743 hard_iface->if_status = BATADV_IF_INACTIVE;
744
745 kref_get(&hard_iface->refcount);
746 hard_iface->batman_adv_ptype.type = ethertype;
747 hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
748 hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
749 dev_add_pack(&hard_iface->batman_adv_ptype);
750
751 batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
752 hard_iface->net_dev->name);
753
754 if (atomic_read(&bat_priv->fragmentation) &&
755 hardif_mtu < required_mtu)
756 batadv_info(hard_iface->soft_iface,
757 "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 %i would solve the problem.\n",
758 hard_iface->net_dev->name, hardif_mtu,
759 required_mtu);
760
761 if (!atomic_read(&bat_priv->fragmentation) &&
762 hardif_mtu < required_mtu)
763 batadv_info(hard_iface->soft_iface,
764 "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 %i.\n",
765 hard_iface->net_dev->name, hardif_mtu,
766 required_mtu);
767
768 if (batadv_hardif_is_iface_up(hard_iface))
769 batadv_hardif_activate_interface(hard_iface);
770 else
771 batadv_err(hard_iface->soft_iface,
772 "Not using interface %s (retrying later): interface not active\n",
773 hard_iface->net_dev->name);
774
775 batadv_hardif_recalc_extra_skbroom(soft_iface);
776
777 if (bat_priv->algo_ops->iface.enabled)
778 bat_priv->algo_ops->iface.enabled(hard_iface);
779
780 out:
781 return 0;
782
783 err_upper:
784 netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
785 err_dev:
786 hard_iface->soft_iface = NULL;
787 dev_put(soft_iface);
788 batadv_hardif_put(hard_iface);
789 return ret;
790 }
791
792 /**
793 * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface
794 * @soft_iface: soft interface to check
795 *
796 * This function is only using RCU for locking - the result can therefore be
797 * off when another function is modifying the list at the same time. The
798 * caller can use the rtnl_lock to make sure that the count is accurate.
799 *
800 * Return: number of connected/enslaved hard interfaces
801 */
802 static size_t batadv_hardif_cnt(const struct net_device *soft_iface)
803 {
804 struct batadv_hard_iface *hard_iface;
805 size_t count = 0;
806
807 rcu_read_lock();
808 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
809 if (hard_iface->soft_iface != soft_iface)
810 continue;
811
812 count++;
813 }
814 rcu_read_unlock();
815
816 return count;
817 }
818
819 /**
820 * batadv_hardif_disable_interface() - Remove hard interface from soft interface
821 * @hard_iface: hard interface to be removed
822 */
823 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface)
824 {
825 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
826 struct batadv_hard_iface *primary_if = NULL;
827
828 batadv_hardif_deactivate_interface(hard_iface);
829
830 if (hard_iface->if_status != BATADV_IF_INACTIVE)
831 goto out;
832
833 batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
834 hard_iface->net_dev->name);
835 dev_remove_pack(&hard_iface->batman_adv_ptype);
836 batadv_hardif_put(hard_iface);
837
838 primary_if = batadv_primary_if_get_selected(bat_priv);
839 if (hard_iface == primary_if) {
840 struct batadv_hard_iface *new_if;
841
842 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
843 batadv_primary_if_select(bat_priv, new_if);
844
845 batadv_hardif_put(new_if);
846 }
847
848 bat_priv->algo_ops->iface.disable(hard_iface);
849 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
850
851 /* delete all references to this hard_iface */
852 batadv_purge_orig_ref(bat_priv);
853 batadv_purge_outstanding_packets(bat_priv, hard_iface);
854 dev_put(hard_iface->soft_iface);
855
856 netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
857 batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
858
859 /* nobody uses this interface anymore */
860 if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1)
861 batadv_gw_check_client_stop(bat_priv);
862
863 hard_iface->soft_iface = NULL;
864 batadv_hardif_put(hard_iface);
865
866 out:
867 batadv_hardif_put(primary_if);
868 }
869
870 static struct batadv_hard_iface *
871 batadv_hardif_add_interface(struct net_device *net_dev)
872 {
873 struct batadv_hard_iface *hard_iface;
874
875 ASSERT_RTNL();
876
877 if (!batadv_is_valid_iface(net_dev))
878 goto out;
879
880 dev_hold(net_dev);
881
882 hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
883 if (!hard_iface)
884 goto release_dev;
885
886 hard_iface->net_dev = net_dev;
887 hard_iface->soft_iface = NULL;
888 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
889
890 INIT_LIST_HEAD(&hard_iface->list);
891 INIT_HLIST_HEAD(&hard_iface->neigh_list);
892
893 mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
894 spin_lock_init(&hard_iface->neigh_list_lock);
895 kref_init(&hard_iface->refcount);
896
897 hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
898 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
899 if (batadv_is_wifi_hardif(hard_iface))
900 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
901
902 atomic_set(&hard_iface->hop_penalty, 0);
903
904 batadv_v_hardif_init(hard_iface);
905
906 batadv_check_known_mac_addr(hard_iface->net_dev);
907 kref_get(&hard_iface->refcount);
908 list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
909 batadv_hardif_generation++;
910
911 return hard_iface;
912
913 release_dev:
914 dev_put(net_dev);
915 out:
916 return NULL;
917 }
918
919 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
920 {
921 ASSERT_RTNL();
922
923 /* first deactivate interface */
924 if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
925 batadv_hardif_disable_interface(hard_iface);
926
927 if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
928 return;
929
930 hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
931 batadv_hardif_put(hard_iface);
932 }
933
934 /**
935 * batadv_hard_if_event_softif() - Handle events for soft interfaces
936 * @event: NETDEV_* event to handle
937 * @net_dev: net_device which generated an event
938 *
939 * Return: NOTIFY_* result
940 */
941 static int batadv_hard_if_event_softif(unsigned long event,
942 struct net_device *net_dev)
943 {
944 struct batadv_priv *bat_priv;
945
946 switch (event) {
947 case NETDEV_REGISTER:
948 bat_priv = netdev_priv(net_dev);
949 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
950 break;
951 }
952
953 return NOTIFY_DONE;
954 }
955
956 static int batadv_hard_if_event(struct notifier_block *this,
957 unsigned long event, void *ptr)
958 {
959 struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
960 struct batadv_hard_iface *hard_iface;
961 struct batadv_hard_iface *primary_if = NULL;
962 struct batadv_priv *bat_priv;
963
964 if (batadv_softif_is_valid(net_dev))
965 return batadv_hard_if_event_softif(event, net_dev);
966
967 hard_iface = batadv_hardif_get_by_netdev(net_dev);
968 if (!hard_iface && (event == NETDEV_REGISTER ||
969 event == NETDEV_POST_TYPE_CHANGE))
970 hard_iface = batadv_hardif_add_interface(net_dev);
971
972 if (!hard_iface)
973 goto out;
974
975 switch (event) {
976 case NETDEV_UP:
977 batadv_hardif_activate_interface(hard_iface);
978 break;
979 case NETDEV_GOING_DOWN:
980 case NETDEV_DOWN:
981 batadv_hardif_deactivate_interface(hard_iface);
982 break;
983 case NETDEV_UNREGISTER:
984 case NETDEV_PRE_TYPE_CHANGE:
985 list_del_rcu(&hard_iface->list);
986 batadv_hardif_generation++;
987
988 batadv_hardif_remove_interface(hard_iface);
989 break;
990 case NETDEV_CHANGEMTU:
991 if (hard_iface->soft_iface)
992 batadv_update_min_mtu(hard_iface->soft_iface);
993 break;
994 case NETDEV_CHANGEADDR:
995 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
996 goto hardif_put;
997
998 batadv_check_known_mac_addr(hard_iface->net_dev);
999
1000 bat_priv = netdev_priv(hard_iface->soft_iface);
1001 bat_priv->algo_ops->iface.update_mac(hard_iface);
1002
1003 primary_if = batadv_primary_if_get_selected(bat_priv);
1004 if (!primary_if)
1005 goto hardif_put;
1006
1007 if (hard_iface == primary_if)
1008 batadv_primary_if_update_addr(bat_priv, NULL);
1009 break;
1010 case NETDEV_CHANGEUPPER:
1011 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1012 if (batadv_is_wifi_hardif(hard_iface))
1013 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1014 break;
1015 default:
1016 break;
1017 }
1018
1019 hardif_put:
1020 batadv_hardif_put(hard_iface);
1021 out:
1022 batadv_hardif_put(primary_if);
1023 return NOTIFY_DONE;
1024 }
1025
1026 struct notifier_block batadv_hard_if_notifier = {
1027 .notifier_call = batadv_hard_if_event,
1028 };
1029
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