1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) B.A.T.M.A.N. contributors:
3 *
4 * Simon Wunderlich
5 */
6
7 #include "bridge_loop_avoidance.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/crc16.h>
15 #include <linux/errno.h>
16 #include <linux/etherdevice.h>
17 #include <linux/gfp.h>
18 #include <linux/if_arp.h>
19 #include <linux/if_ether.h>
20 #include <linux/if_vlan.h>
21 #include <linux/jhash.h>
22 #include <linux/jiffies.h>
23 #include <linux/kref.h>
24 #include <linux/list.h>
25 #include <linux/lockdep.h>
26 #include <linux/netdevice.h>
27 #include <linux/netlink.h>
28 #include <linux/rculist.h>
29 #include <linux/rcupdate.h>
30 #include <linux/skbuff.h>
31 #include <linux/slab.h>
32 #include <linux/spinlock.h>
33 #include <linux/sprintf.h>
34 #include <linux/stddef.h>
35 #include <linux/string.h>
36 #include <linux/workqueue.h>
37 #include <net/arp.h>
38 #include <net/genetlink.h>
39 #include <net/netlink.h>
40 #include <net/sock.h>
41 #include <uapi/linux/batadv_packet.h>
42 #include <uapi/linux/batman_adv.h>
43
44 #include "hard-interface.h"
45 #include "hash.h"
46 #include "log.h"
47 #include "netlink.h"
48 #include "originator.h"
49 #include "soft-interface.h"
50 #include "translation-table.h"
51
52 static const u8 batadv_announce_mac[4] = {0x43, 0x05, 0x43, 0x05};
53
54 static void batadv_bla_periodic_work(struct work_struct *work);
55 static void
56 batadv_bla_send_announce(struct batadv_priv *bat_priv,
57 struct batadv_bla_backbone_gw *backbone_gw);
58
59 /**
60 * batadv_choose_claim() - choose the right bucket for a claim.
61 * @data: data to hash
62 * @size: size of the hash table
63 *
64 * Return: the hash index of the claim
65 */
66 static inline u32 batadv_choose_claim(const void *data, u32 size)
67 {
68 const struct batadv_bla_claim *claim = data;
69 u32 hash = 0;
70
71 hash = jhash(&claim->addr, sizeof(claim->addr), hash);
72 hash = jhash(&claim->vid, sizeof(claim->vid), hash);
73
74 return hash % size;
75 }
76
77 /**
78 * batadv_choose_backbone_gw() - choose the right bucket for a backbone gateway.
79 * @data: data to hash
80 * @size: size of the hash table
81 *
82 * Return: the hash index of the backbone gateway
83 */
84 static inline u32 batadv_choose_backbone_gw(const void *data, u32 size)
85 {
86 const struct batadv_bla_backbone_gw *gw;
87 u32 hash = 0;
88
89 gw = data;
90 hash = jhash(&gw->orig, sizeof(gw->orig), hash);
91 hash = jhash(&gw->vid, sizeof(gw->vid), hash);
92
93 return hash % size;
94 }
95
96 /**
97 * batadv_compare_backbone_gw() - compare address and vid of two backbone gws
98 * @node: list node of the first entry to compare
99 * @data2: pointer to the second backbone gateway
100 *
101 * Return: true if the backbones have the same data, false otherwise
102 */
103 static bool batadv_compare_backbone_gw(const struct hlist_node *node,
104 const void *data2)
105 {
106 const void *data1 = container_of(node, struct batadv_bla_backbone_gw,
107 hash_entry);
108 const struct batadv_bla_backbone_gw *gw1 = data1;
109 const struct batadv_bla_backbone_gw *gw2 = data2;
110
111 if (!batadv_compare_eth(gw1->orig, gw2->orig))
112 return false;
113
114 if (gw1->vid != gw2->vid)
115 return false;
116
117 return true;
118 }
119
120 /**
121 * batadv_compare_claim() - compare address and vid of two claims
122 * @node: list node of the first entry to compare
123 * @data2: pointer to the second claims
124 *
125 * Return: true if the claim have the same data, 0 otherwise
126 */
127 static bool batadv_compare_claim(const struct hlist_node *node,
128 const void *data2)
129 {
130 const void *data1 = container_of(node, struct batadv_bla_claim,
131 hash_entry);
132 const struct batadv_bla_claim *cl1 = data1;
133 const struct batadv_bla_claim *cl2 = data2;
134
135 if (!batadv_compare_eth(cl1->addr, cl2->addr))
136 return false;
137
138 if (cl1->vid != cl2->vid)
139 return false;
140
141 return true;
142 }
143
144 /**
145 * batadv_backbone_gw_release() - release backbone gw from lists and queue for
146 * free after rcu grace period
147 * @ref: kref pointer of the backbone gw
148 */
149 static void batadv_backbone_gw_release(struct kref *ref)
150 {
151 struct batadv_bla_backbone_gw *backbone_gw;
152
153 backbone_gw = container_of(ref, struct batadv_bla_backbone_gw,
154 refcount);
155
156 kfree_rcu(backbone_gw, rcu);
157 }
158
159 /**
160 * batadv_backbone_gw_put() - decrement the backbone gw refcounter and possibly
161 * release it
162 * @backbone_gw: backbone gateway to be free'd
163 */
164 static void batadv_backbone_gw_put(struct batadv_bla_backbone_gw *backbone_gw)
165 {
166 if (!backbone_gw)
167 return;
168
169 kref_put(&backbone_gw->refcount, batadv_backbone_gw_release);
170 }
171
172 /**
173 * batadv_claim_release() - release claim from lists and queue for free after
174 * rcu grace period
175 * @ref: kref pointer of the claim
176 */
177 static void batadv_claim_release(struct kref *ref)
178 {
179 struct batadv_bla_claim *claim;
180 struct batadv_bla_backbone_gw *old_backbone_gw;
181
182 claim = container_of(ref, struct batadv_bla_claim, refcount);
183
184 spin_lock_bh(&claim->backbone_lock);
185 old_backbone_gw = claim->backbone_gw;
186 claim->backbone_gw = NULL;
187 spin_unlock_bh(&claim->backbone_lock);
188
189 spin_lock_bh(&old_backbone_gw->crc_lock);
190 old_backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
191 spin_unlock_bh(&old_backbone_gw->crc_lock);
192
193 batadv_backbone_gw_put(old_backbone_gw);
194
195 kfree_rcu(claim, rcu);
196 }
197
198 /**
199 * batadv_claim_put() - decrement the claim refcounter and possibly release it
200 * @claim: claim to be free'd
201 */
202 static void batadv_claim_put(struct batadv_bla_claim *claim)
203 {
204 if (!claim)
205 return;
206
207 kref_put(&claim->refcount, batadv_claim_release);
208 }
209
210 /**
211 * batadv_claim_hash_find() - looks for a claim in the claim hash
212 * @bat_priv: the bat priv with all the soft interface information
213 * @data: search data (may be local/static data)
214 *
215 * Return: claim if found or NULL otherwise.
216 */
217 static struct batadv_bla_claim *
218 batadv_claim_hash_find(struct batadv_priv *bat_priv,
219 struct batadv_bla_claim *data)
220 {
221 struct batadv_hashtable *hash = bat_priv->bla.claim_hash;
222 struct hlist_head *head;
223 struct batadv_bla_claim *claim;
224 struct batadv_bla_claim *claim_tmp = NULL;
225 int index;
226
227 if (!hash)
228 return NULL;
229
230 index = batadv_choose_claim(data, hash->size);
231 head = &hash->table[index];
232
233 rcu_read_lock();
234 hlist_for_each_entry_rcu(claim, head, hash_entry) {
235 if (!batadv_compare_claim(&claim->hash_entry, data))
236 continue;
237
238 if (!kref_get_unless_zero(&claim->refcount))
239 continue;
240
241 claim_tmp = claim;
242 break;
243 }
244 rcu_read_unlock();
245
246 return claim_tmp;
247 }
248
249 /**
250 * batadv_backbone_hash_find() - looks for a backbone gateway in the hash
251 * @bat_priv: the bat priv with all the soft interface information
252 * @addr: the address of the originator
253 * @vid: the VLAN ID
254 *
255 * Return: backbone gateway if found or NULL otherwise
256 */
257 static struct batadv_bla_backbone_gw *
258 batadv_backbone_hash_find(struct batadv_priv *bat_priv, const u8 *addr,
259 unsigned short vid)
260 {
261 struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
262 struct hlist_head *head;
263 struct batadv_bla_backbone_gw search_entry, *backbone_gw;
264 struct batadv_bla_backbone_gw *backbone_gw_tmp = NULL;
265 int index;
266
267 if (!hash)
268 return NULL;
269
270 ether_addr_copy(search_entry.orig, addr);
271 search_entry.vid = vid;
272
273 index = batadv_choose_backbone_gw(&search_entry, hash->size);
274 head = &hash->table[index];
275
276 rcu_read_lock();
277 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
278 if (!batadv_compare_backbone_gw(&backbone_gw->hash_entry,
279 &search_entry))
280 continue;
281
282 if (!kref_get_unless_zero(&backbone_gw->refcount))
283 continue;
284
285 backbone_gw_tmp = backbone_gw;
286 break;
287 }
288 rcu_read_unlock();
289
290 return backbone_gw_tmp;
291 }
292
293 /**
294 * batadv_bla_del_backbone_claims() - delete all claims for a backbone
295 * @backbone_gw: backbone gateway where the claims should be removed
296 */
297 static void
298 batadv_bla_del_backbone_claims(struct batadv_bla_backbone_gw *backbone_gw)
299 {
300 struct batadv_hashtable *hash;
301 struct hlist_node *node_tmp;
302 struct hlist_head *head;
303 struct batadv_bla_claim *claim;
304 int i;
305 spinlock_t *list_lock; /* protects write access to the hash lists */
306
307 hash = backbone_gw->bat_priv->bla.claim_hash;
308 if (!hash)
309 return;
310
311 for (i = 0; i < hash->size; i++) {
312 head = &hash->table[i];
313 list_lock = &hash->list_locks[i];
314
315 spin_lock_bh(list_lock);
316 hlist_for_each_entry_safe(claim, node_tmp,
317 head, hash_entry) {
318 if (claim->backbone_gw != backbone_gw)
319 continue;
320
321 batadv_claim_put(claim);
322 hlist_del_rcu(&claim->hash_entry);
323 }
324 spin_unlock_bh(list_lock);
325 }
326
327 /* all claims gone, initialize CRC */
328 spin_lock_bh(&backbone_gw->crc_lock);
329 backbone_gw->crc = BATADV_BLA_CRC_INIT;
330 spin_unlock_bh(&backbone_gw->crc_lock);
331 }
332
333 /**
334 * batadv_bla_send_claim() - sends a claim frame according to the provided info
335 * @bat_priv: the bat priv with all the soft interface information
336 * @mac: the mac address to be announced within the claim
337 * @vid: the VLAN ID
338 * @claimtype: the type of the claim (CLAIM, UNCLAIM, ANNOUNCE, ...)
339 */
340 static void batadv_bla_send_claim(struct batadv_priv *bat_priv, const u8 *mac,
341 unsigned short vid, int claimtype)
342 {
343 struct sk_buff *skb;
344 struct ethhdr *ethhdr;
345 struct batadv_hard_iface *primary_if;
346 struct net_device *soft_iface;
347 u8 *hw_src;
348 struct batadv_bla_claim_dst local_claim_dest;
349 __be32 zeroip = 0;
350
351 primary_if = batadv_primary_if_get_selected(bat_priv);
352 if (!primary_if)
353 return;
354
355 memcpy(&local_claim_dest, &bat_priv->bla.claim_dest,
356 sizeof(local_claim_dest));
357 local_claim_dest.type = claimtype;
358
359 soft_iface = primary_if->soft_iface;
360
361 skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
362 /* IP DST: 0.0.0.0 */
363 zeroip,
364 primary_if->soft_iface,
365 /* IP SRC: 0.0.0.0 */
366 zeroip,
367 /* Ethernet DST: Broadcast */
368 NULL,
369 /* Ethernet SRC/HW SRC: originator mac */
370 primary_if->net_dev->dev_addr,
371 /* HW DST: FF:43:05:XX:YY:YY
372 * with XX = claim type
373 * and YY:YY = group id
374 */
375 (u8 *)&local_claim_dest);
376
377 if (!skb)
378 goto out;
379
380 ethhdr = (struct ethhdr *)skb->data;
381 hw_src = (u8 *)ethhdr + ETH_HLEN + sizeof(struct arphdr);
382
383 /* now we pretend that the client would have sent this ... */
384 switch (claimtype) {
385 case BATADV_CLAIM_TYPE_CLAIM:
386 /* normal claim frame
387 * set Ethernet SRC to the clients mac
388 */
389 ether_addr_copy(ethhdr->h_source, mac);
390 batadv_dbg(BATADV_DBG_BLA, bat_priv,
391 "%s(): CLAIM %pM on vid %d\n", __func__, mac,
392 batadv_print_vid(vid));
393 break;
394 case BATADV_CLAIM_TYPE_UNCLAIM:
395 /* unclaim frame
396 * set HW SRC to the clients mac
397 */
398 ether_addr_copy(hw_src, mac);
399 batadv_dbg(BATADV_DBG_BLA, bat_priv,
400 "%s(): UNCLAIM %pM on vid %d\n", __func__, mac,
401 batadv_print_vid(vid));
402 break;
403 case BATADV_CLAIM_TYPE_ANNOUNCE:
404 /* announcement frame
405 * set HW SRC to the special mac containing the crc
406 */
407 ether_addr_copy(hw_src, mac);
408 batadv_dbg(BATADV_DBG_BLA, bat_priv,
409 "%s(): ANNOUNCE of %pM on vid %d\n", __func__,
410 ethhdr->h_source, batadv_print_vid(vid));
411 break;
412 case BATADV_CLAIM_TYPE_REQUEST:
413 /* request frame
414 * set HW SRC and header destination to the receiving backbone
415 * gws mac
416 */
417 ether_addr_copy(hw_src, mac);
418 ether_addr_copy(ethhdr->h_dest, mac);
419 batadv_dbg(BATADV_DBG_BLA, bat_priv,
420 "%s(): REQUEST of %pM to %pM on vid %d\n", __func__,
421 ethhdr->h_source, ethhdr->h_dest,
422 batadv_print_vid(vid));
423 break;
424 case BATADV_CLAIM_TYPE_LOOPDETECT:
425 ether_addr_copy(ethhdr->h_source, mac);
426 batadv_dbg(BATADV_DBG_BLA, bat_priv,
427 "%s(): LOOPDETECT of %pM to %pM on vid %d\n",
428 __func__, ethhdr->h_source, ethhdr->h_dest,
429 batadv_print_vid(vid));
430
431 break;
432 }
433
434 if (vid & BATADV_VLAN_HAS_TAG) {
435 skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
436 vid & VLAN_VID_MASK);
437 if (!skb)
438 goto out;
439 }
440
441 skb_reset_mac_header(skb);
442 skb->protocol = eth_type_trans(skb, soft_iface);
443 batadv_inc_counter(bat_priv, BATADV_CNT_RX);
444 batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
445 skb->len + ETH_HLEN);
446
447 netif_rx(skb);
448 out:
449 batadv_hardif_put(primary_if);
450 }
451
452 /**
453 * batadv_bla_loopdetect_report() - worker for reporting the loop
454 * @work: work queue item
455 *
456 * Throws an uevent, as the loopdetect check function can't do that itself
457 * since the kernel may sleep while throwing uevents.
458 */
459 static void batadv_bla_loopdetect_report(struct work_struct *work)
460 {
461 struct batadv_bla_backbone_gw *backbone_gw;
462 struct batadv_priv *bat_priv;
463 char vid_str[6] = { '\0' };
464
465 backbone_gw = container_of(work, struct batadv_bla_backbone_gw,
466 report_work);
467 bat_priv = backbone_gw->bat_priv;
468
469 batadv_info(bat_priv->soft_iface,
470 "Possible loop on VLAN %d detected which can't be handled by BLA - please check your network setup!\n",
471 batadv_print_vid(backbone_gw->vid));
472 snprintf(vid_str, sizeof(vid_str), "%d",
473 batadv_print_vid(backbone_gw->vid));
474 vid_str[sizeof(vid_str) - 1] = 0;
475
476 batadv_throw_uevent(bat_priv, BATADV_UEV_BLA, BATADV_UEV_LOOPDETECT,
477 vid_str);
478
479 batadv_backbone_gw_put(backbone_gw);
480 }
481
482 /**
483 * batadv_bla_get_backbone_gw() - finds or creates a backbone gateway
484 * @bat_priv: the bat priv with all the soft interface information
485 * @orig: the mac address of the originator
486 * @vid: the VLAN ID
487 * @own_backbone: set if the requested backbone is local
488 *
489 * Return: the (possibly created) backbone gateway or NULL on error
490 */
491 static struct batadv_bla_backbone_gw *
492 batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, const u8 *orig,
493 unsigned short vid, bool own_backbone)
494 {
495 struct batadv_bla_backbone_gw *entry;
496 struct batadv_orig_node *orig_node;
497 int hash_added;
498
499 entry = batadv_backbone_hash_find(bat_priv, orig, vid);
500
501 if (entry)
502 return entry;
503
504 batadv_dbg(BATADV_DBG_BLA, bat_priv,
505 "%s(): not found (%pM, %d), creating new entry\n", __func__,
506 orig, batadv_print_vid(vid));
507
508 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
509 if (!entry)
510 return NULL;
511
512 entry->vid = vid;
513 entry->lasttime = jiffies;
514 entry->crc = BATADV_BLA_CRC_INIT;
515 entry->bat_priv = bat_priv;
516 spin_lock_init(&entry->crc_lock);
517 atomic_set(&entry->request_sent, 0);
518 atomic_set(&entry->wait_periods, 0);
519 ether_addr_copy(entry->orig, orig);
520 INIT_WORK(&entry->report_work, batadv_bla_loopdetect_report);
521 kref_init(&entry->refcount);
522
523 kref_get(&entry->refcount);
524 hash_added = batadv_hash_add(bat_priv->bla.backbone_hash,
525 batadv_compare_backbone_gw,
526 batadv_choose_backbone_gw, entry,
527 &entry->hash_entry);
528
529 if (unlikely(hash_added != 0)) {
530 /* hash failed, free the structure */
531 kfree(entry);
532 return NULL;
533 }
534
535 /* this is a gateway now, remove any TT entry on this VLAN */
536 orig_node = batadv_orig_hash_find(bat_priv, orig);
537 if (orig_node) {
538 batadv_tt_global_del_orig(bat_priv, orig_node, vid,
539 "became a backbone gateway");
540 batadv_orig_node_put(orig_node);
541 }
542
543 if (own_backbone) {
544 batadv_bla_send_announce(bat_priv, entry);
545
546 /* this will be decreased in the worker thread */
547 atomic_inc(&entry->request_sent);
548 atomic_set(&entry->wait_periods, BATADV_BLA_WAIT_PERIODS);
549 atomic_inc(&bat_priv->bla.num_requests);
550 }
551
552 return entry;
553 }
554
555 /**
556 * batadv_bla_update_own_backbone_gw() - updates the own backbone gw for a VLAN
557 * @bat_priv: the bat priv with all the soft interface information
558 * @primary_if: the selected primary interface
559 * @vid: VLAN identifier
560 *
561 * update or add the own backbone gw to make sure we announce
562 * where we receive other backbone gws
563 */
564 static void
565 batadv_bla_update_own_backbone_gw(struct batadv_priv *bat_priv,
566 struct batadv_hard_iface *primary_if,
567 unsigned short vid)
568 {
569 struct batadv_bla_backbone_gw *backbone_gw;
570
571 backbone_gw = batadv_bla_get_backbone_gw(bat_priv,
572 primary_if->net_dev->dev_addr,
573 vid, true);
574 if (unlikely(!backbone_gw))
575 return;
576
577 backbone_gw->lasttime = jiffies;
578 batadv_backbone_gw_put(backbone_gw);
579 }
580
581 /**
582 * batadv_bla_answer_request() - answer a bla request by sending own claims
583 * @bat_priv: the bat priv with all the soft interface information
584 * @primary_if: interface where the request came on
585 * @vid: the vid where the request came on
586 *
587 * Repeat all of our own claims, and finally send an ANNOUNCE frame
588 * to allow the requester another check if the CRC is correct now.
589 */
590 static void batadv_bla_answer_request(struct batadv_priv *bat_priv,
591 struct batadv_hard_iface *primary_if,
592 unsigned short vid)
593 {
594 struct hlist_head *head;
595 struct batadv_hashtable *hash;
596 struct batadv_bla_claim *claim;
597 struct batadv_bla_backbone_gw *backbone_gw;
598 int i;
599
600 batadv_dbg(BATADV_DBG_BLA, bat_priv,
601 "%s(): received a claim request, send all of our own claims again\n",
602 __func__);
603
604 backbone_gw = batadv_backbone_hash_find(bat_priv,
605 primary_if->net_dev->dev_addr,
606 vid);
607 if (!backbone_gw)
608 return;
609
610 hash = bat_priv->bla.claim_hash;
611 for (i = 0; i < hash->size; i++) {
612 head = &hash->table[i];
613
614 rcu_read_lock();
615 hlist_for_each_entry_rcu(claim, head, hash_entry) {
616 /* only own claims are interesting */
617 if (claim->backbone_gw != backbone_gw)
618 continue;
619
620 batadv_bla_send_claim(bat_priv, claim->addr, claim->vid,
621 BATADV_CLAIM_TYPE_CLAIM);
622 }
623 rcu_read_unlock();
624 }
625
626 /* finally, send an announcement frame */
627 batadv_bla_send_announce(bat_priv, backbone_gw);
628 batadv_backbone_gw_put(backbone_gw);
629 }
630
631 /**
632 * batadv_bla_send_request() - send a request to repeat claims
633 * @backbone_gw: the backbone gateway from whom we are out of sync
634 *
635 * When the crc is wrong, ask the backbone gateway for a full table update.
636 * After the request, it will repeat all of his own claims and finally
637 * send an announcement claim with which we can check again.
638 */
639 static void batadv_bla_send_request(struct batadv_bla_backbone_gw *backbone_gw)
640 {
641 /* first, remove all old entries */
642 batadv_bla_del_backbone_claims(backbone_gw);
643
644 batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
645 "Sending REQUEST to %pM\n", backbone_gw->orig);
646
647 /* send request */
648 batadv_bla_send_claim(backbone_gw->bat_priv, backbone_gw->orig,
649 backbone_gw->vid, BATADV_CLAIM_TYPE_REQUEST);
650
651 /* no local broadcasts should be sent or received, for now. */
652 if (!atomic_read(&backbone_gw->request_sent)) {
653 atomic_inc(&backbone_gw->bat_priv->bla.num_requests);
654 atomic_set(&backbone_gw->request_sent, 1);
655 }
656 }
657
658 /**
659 * batadv_bla_send_announce() - Send an announcement frame
660 * @bat_priv: the bat priv with all the soft interface information
661 * @backbone_gw: our backbone gateway which should be announced
662 */
663 static void batadv_bla_send_announce(struct batadv_priv *bat_priv,
664 struct batadv_bla_backbone_gw *backbone_gw)
665 {
666 u8 mac[ETH_ALEN];
667 __be16 crc;
668
669 memcpy(mac, batadv_announce_mac, 4);
670 spin_lock_bh(&backbone_gw->crc_lock);
671 crc = htons(backbone_gw->crc);
672 spin_unlock_bh(&backbone_gw->crc_lock);
673 memcpy(&mac[4], &crc, 2);
674
675 batadv_bla_send_claim(bat_priv, mac, backbone_gw->vid,
676 BATADV_CLAIM_TYPE_ANNOUNCE);
677 }
678
679 /**
680 * batadv_bla_add_claim() - Adds a claim in the claim hash
681 * @bat_priv: the bat priv with all the soft interface information
682 * @mac: the mac address of the claim
683 * @vid: the VLAN ID of the frame
684 * @backbone_gw: the backbone gateway which claims it
685 */
686 static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
687 const u8 *mac, const unsigned short vid,
688 struct batadv_bla_backbone_gw *backbone_gw)
689 {
690 struct batadv_bla_backbone_gw *old_backbone_gw;
691 struct batadv_bla_claim *claim;
692 struct batadv_bla_claim search_claim;
693 bool remove_crc = false;
694 int hash_added;
695
696 ether_addr_copy(search_claim.addr, mac);
697 search_claim.vid = vid;
698 claim = batadv_claim_hash_find(bat_priv, &search_claim);
699
700 /* create a new claim entry if it does not exist yet. */
701 if (!claim) {
702 claim = kzalloc(sizeof(*claim), GFP_ATOMIC);
703 if (!claim)
704 return;
705
706 ether_addr_copy(claim->addr, mac);
707 spin_lock_init(&claim->backbone_lock);
708 claim->vid = vid;
709 claim->lasttime = jiffies;
710 kref_get(&backbone_gw->refcount);
711 claim->backbone_gw = backbone_gw;
712 kref_init(&claim->refcount);
713
714 batadv_dbg(BATADV_DBG_BLA, bat_priv,
715 "%s(): adding new entry %pM, vid %d to hash ...\n",
716 __func__, mac, batadv_print_vid(vid));
717
718 kref_get(&claim->refcount);
719 hash_added = batadv_hash_add(bat_priv->bla.claim_hash,
720 batadv_compare_claim,
721 batadv_choose_claim, claim,
722 &claim->hash_entry);
723
724 if (unlikely(hash_added != 0)) {
725 /* only local changes happened. */
726 kfree(claim);
727 return;
728 }
729 } else {
730 claim->lasttime = jiffies;
731 if (claim->backbone_gw == backbone_gw)
732 /* no need to register a new backbone */
733 goto claim_free_ref;
734
735 batadv_dbg(BATADV_DBG_BLA, bat_priv,
736 "%s(): changing ownership for %pM, vid %d to gw %pM\n",
737 __func__, mac, batadv_print_vid(vid),
738 backbone_gw->orig);
739
740 remove_crc = true;
741 }
742
743 /* replace backbone_gw atomically and adjust reference counters */
744 spin_lock_bh(&claim->backbone_lock);
745 old_backbone_gw = claim->backbone_gw;
746 kref_get(&backbone_gw->refcount);
747 claim->backbone_gw = backbone_gw;
748 spin_unlock_bh(&claim->backbone_lock);
749
750 if (remove_crc) {
751 /* remove claim address from old backbone_gw */
752 spin_lock_bh(&old_backbone_gw->crc_lock);
753 old_backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
754 spin_unlock_bh(&old_backbone_gw->crc_lock);
755 }
756
757 batadv_backbone_gw_put(old_backbone_gw);
758
759 /* add claim address to new backbone_gw */
760 spin_lock_bh(&backbone_gw->crc_lock);
761 backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
762 spin_unlock_bh(&backbone_gw->crc_lock);
763 backbone_gw->lasttime = jiffies;
764
765 claim_free_ref:
766 batadv_claim_put(claim);
767 }
768
769 /**
770 * batadv_bla_claim_get_backbone_gw() - Get valid reference for backbone_gw of
771 * claim
772 * @claim: claim whose backbone_gw should be returned
773 *
774 * Return: valid reference to claim::backbone_gw
775 */
776 static struct batadv_bla_backbone_gw *
777 batadv_bla_claim_get_backbone_gw(struct batadv_bla_claim *claim)
778 {
779 struct batadv_bla_backbone_gw *backbone_gw;
780
781 spin_lock_bh(&claim->backbone_lock);
782 backbone_gw = claim->backbone_gw;
783 kref_get(&backbone_gw->refcount);
784 spin_unlock_bh(&claim->backbone_lock);
785
786 return backbone_gw;
787 }
788
789 /**
790 * batadv_bla_del_claim() - delete a claim from the claim hash
791 * @bat_priv: the bat priv with all the soft interface information
792 * @mac: mac address of the claim to be removed
793 * @vid: VLAN id for the claim to be removed
794 */
795 static void batadv_bla_del_claim(struct batadv_priv *bat_priv,
796 const u8 *mac, const unsigned short vid)
797 {
798 struct batadv_bla_claim search_claim, *claim;
799 struct batadv_bla_claim *claim_removed_entry;
800 struct hlist_node *claim_removed_node;
801
802 ether_addr_copy(search_claim.addr, mac);
803 search_claim.vid = vid;
804 claim = batadv_claim_hash_find(bat_priv, &search_claim);
805 if (!claim)
806 return;
807
808 batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): %pM, vid %d\n", __func__,
809 mac, batadv_print_vid(vid));
810
811 claim_removed_node = batadv_hash_remove(bat_priv->bla.claim_hash,
812 batadv_compare_claim,
813 batadv_choose_claim, claim);
814 if (!claim_removed_node)
815 goto free_claim;
816
817 /* reference from the hash is gone */
818 claim_removed_entry = hlist_entry(claim_removed_node,
819 struct batadv_bla_claim, hash_entry);
820 batadv_claim_put(claim_removed_entry);
821
822 free_claim:
823 /* don't need the reference from hash_find() anymore */
824 batadv_claim_put(claim);
825 }
826
827 /**
828 * batadv_handle_announce() - check for ANNOUNCE frame
829 * @bat_priv: the bat priv with all the soft interface information
830 * @an_addr: announcement mac address (ARP Sender HW address)
831 * @backbone_addr: originator address of the sender (Ethernet source MAC)
832 * @vid: the VLAN ID of the frame
833 *
834 * Return: true if handled
835 */
836 static bool batadv_handle_announce(struct batadv_priv *bat_priv, u8 *an_addr,
837 u8 *backbone_addr, unsigned short vid)
838 {
839 struct batadv_bla_backbone_gw *backbone_gw;
840 u16 backbone_crc, crc;
841
842 if (memcmp(an_addr, batadv_announce_mac, 4) != 0)
843 return false;
844
845 backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
846 false);
847
848 if (unlikely(!backbone_gw))
849 return true;
850
851 /* handle as ANNOUNCE frame */
852 backbone_gw->lasttime = jiffies;
853 crc = ntohs(*((__force __be16 *)(&an_addr[4])));
854
855 batadv_dbg(BATADV_DBG_BLA, bat_priv,
856 "%s(): ANNOUNCE vid %d (sent by %pM)... CRC = %#.4x\n",
857 __func__, batadv_print_vid(vid), backbone_gw->orig, crc);
858
859 spin_lock_bh(&backbone_gw->crc_lock);
860 backbone_crc = backbone_gw->crc;
861 spin_unlock_bh(&backbone_gw->crc_lock);
862
863 if (backbone_crc != crc) {
864 batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
865 "%s(): CRC FAILED for %pM/%d (my = %#.4x, sent = %#.4x)\n",
866 __func__, backbone_gw->orig,
867 batadv_print_vid(backbone_gw->vid),
868 backbone_crc, crc);
869
870 batadv_bla_send_request(backbone_gw);
871 } else {
872 /* if we have sent a request and the crc was OK,
873 * we can allow traffic again.
874 */
875 if (atomic_read(&backbone_gw->request_sent)) {
876 atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
877 atomic_set(&backbone_gw->request_sent, 0);
878 }
879 }
880
881 batadv_backbone_gw_put(backbone_gw);
882 return true;
883 }
884
885 /**
886 * batadv_handle_request() - check for REQUEST frame
887 * @bat_priv: the bat priv with all the soft interface information
888 * @primary_if: the primary hard interface of this batman soft interface
889 * @backbone_addr: backbone address to be requested (ARP sender HW MAC)
890 * @ethhdr: ethernet header of a packet
891 * @vid: the VLAN ID of the frame
892 *
893 * Return: true if handled
894 */
895 static bool batadv_handle_request(struct batadv_priv *bat_priv,
896 struct batadv_hard_iface *primary_if,
897 u8 *backbone_addr, struct ethhdr *ethhdr,
898 unsigned short vid)
899 {
900 /* check for REQUEST frame */
901 if (!batadv_compare_eth(backbone_addr, ethhdr->h_dest))
902 return false;
903
904 /* sanity check, this should not happen on a normal switch,
905 * we ignore it in this case.
906 */
907 if (!batadv_compare_eth(ethhdr->h_dest, primary_if->net_dev->dev_addr))
908 return true;
909
910 batadv_dbg(BATADV_DBG_BLA, bat_priv,
911 "%s(): REQUEST vid %d (sent by %pM)...\n",
912 __func__, batadv_print_vid(vid), ethhdr->h_source);
913
914 batadv_bla_answer_request(bat_priv, primary_if, vid);
915 return true;
916 }
917
918 /**
919 * batadv_handle_unclaim() - check for UNCLAIM frame
920 * @bat_priv: the bat priv with all the soft interface information
921 * @primary_if: the primary hard interface of this batman soft interface
922 * @backbone_addr: originator address of the backbone (Ethernet source)
923 * @claim_addr: Client to be unclaimed (ARP sender HW MAC)
924 * @vid: the VLAN ID of the frame
925 *
926 * Return: true if handled
927 */
928 static bool batadv_handle_unclaim(struct batadv_priv *bat_priv,
929 struct batadv_hard_iface *primary_if,
930 const u8 *backbone_addr, const u8 *claim_addr,
931 unsigned short vid)
932 {
933 struct batadv_bla_backbone_gw *backbone_gw;
934
935 /* unclaim in any case if it is our own */
936 if (primary_if && batadv_compare_eth(backbone_addr,
937 primary_if->net_dev->dev_addr))
938 batadv_bla_send_claim(bat_priv, claim_addr, vid,
939 BATADV_CLAIM_TYPE_UNCLAIM);
940
941 backbone_gw = batadv_backbone_hash_find(bat_priv, backbone_addr, vid);
942
943 if (!backbone_gw)
944 return true;
945
946 /* this must be an UNCLAIM frame */
947 batadv_dbg(BATADV_DBG_BLA, bat_priv,
948 "%s(): UNCLAIM %pM on vid %d (sent by %pM)...\n", __func__,
949 claim_addr, batadv_print_vid(vid), backbone_gw->orig);
950
951 batadv_bla_del_claim(bat_priv, claim_addr, vid);
952 batadv_backbone_gw_put(backbone_gw);
953 return true;
954 }
955
956 /**
957 * batadv_handle_claim() - check for CLAIM frame
958 * @bat_priv: the bat priv with all the soft interface information
959 * @primary_if: the primary hard interface of this batman soft interface
960 * @backbone_addr: originator address of the backbone (Ethernet Source)
961 * @claim_addr: client mac address to be claimed (ARP sender HW MAC)
962 * @vid: the VLAN ID of the frame
963 *
964 * Return: true if handled
965 */
966 static bool batadv_handle_claim(struct batadv_priv *bat_priv,
967 struct batadv_hard_iface *primary_if,
968 const u8 *backbone_addr, const u8 *claim_addr,
969 unsigned short vid)
970 {
971 struct batadv_bla_backbone_gw *backbone_gw;
972
973 /* register the gateway if not yet available, and add the claim. */
974
975 backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
976 false);
977
978 if (unlikely(!backbone_gw))
979 return true;
980
981 /* this must be a CLAIM frame */
982 batadv_bla_add_claim(bat_priv, claim_addr, vid, backbone_gw);
983 if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
984 batadv_bla_send_claim(bat_priv, claim_addr, vid,
985 BATADV_CLAIM_TYPE_CLAIM);
986
987 /* TODO: we could call something like tt_local_del() here. */
988
989 batadv_backbone_gw_put(backbone_gw);
990 return true;
991 }
992
993 /**
994 * batadv_check_claim_group() - check for claim group membership
995 * @bat_priv: the bat priv with all the soft interface information
996 * @primary_if: the primary interface of this batman interface
997 * @hw_src: the Hardware source in the ARP Header
998 * @hw_dst: the Hardware destination in the ARP Header
999 * @ethhdr: pointer to the Ethernet header of the claim frame
1000 *
1001 * checks if it is a claim packet and if it's on the same group.
1002 * This function also applies the group ID of the sender
1003 * if it is in the same mesh.
1004 *
1005 * Return:
1006 * 2 - if it is a claim packet and on the same group
1007 * 1 - if is a claim packet from another group
1008 * 0 - if it is not a claim packet
1009 */
1010 static int batadv_check_claim_group(struct batadv_priv *bat_priv,
1011 struct batadv_hard_iface *primary_if,
1012 u8 *hw_src, u8 *hw_dst,
1013 struct ethhdr *ethhdr)
1014 {
1015 u8 *backbone_addr;
1016 struct batadv_orig_node *orig_node;
1017 struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
1018
1019 bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
1020 bla_dst_own = &bat_priv->bla.claim_dest;
1021
1022 /* if announcement packet, use the source,
1023 * otherwise assume it is in the hw_src
1024 */
1025 switch (bla_dst->type) {
1026 case BATADV_CLAIM_TYPE_CLAIM:
1027 backbone_addr = hw_src;
1028 break;
1029 case BATADV_CLAIM_TYPE_REQUEST:
1030 case BATADV_CLAIM_TYPE_ANNOUNCE:
1031 case BATADV_CLAIM_TYPE_UNCLAIM:
1032 backbone_addr = ethhdr->h_source;
1033 break;
1034 default:
1035 return 0;
1036 }
1037
1038 /* don't accept claim frames from ourselves */
1039 if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
1040 return 0;
1041
1042 /* if its already the same group, it is fine. */
1043 if (bla_dst->group == bla_dst_own->group)
1044 return 2;
1045
1046 /* lets see if this originator is in our mesh */
1047 orig_node = batadv_orig_hash_find(bat_priv, backbone_addr);
1048
1049 /* don't accept claims from gateways which are not in
1050 * the same mesh or group.
1051 */
1052 if (!orig_node)
1053 return 1;
1054
1055 /* if our mesh friends mac is bigger, use it for ourselves. */
1056 if (ntohs(bla_dst->group) > ntohs(bla_dst_own->group)) {
1057 batadv_dbg(BATADV_DBG_BLA, bat_priv,
1058 "taking other backbones claim group: %#.4x\n",
1059 ntohs(bla_dst->group));
1060 bla_dst_own->group = bla_dst->group;
1061 }
1062
1063 batadv_orig_node_put(orig_node);
1064
1065 return 2;
1066 }
1067
1068 /**
1069 * batadv_bla_process_claim() - Check if this is a claim frame, and process it
1070 * @bat_priv: the bat priv with all the soft interface information
1071 * @primary_if: the primary hard interface of this batman soft interface
1072 * @skb: the frame to be checked
1073 *
1074 * Return: true if it was a claim frame, otherwise return false to
1075 * tell the callee that it can use the frame on its own.
1076 */
1077 static bool batadv_bla_process_claim(struct batadv_priv *bat_priv,
1078 struct batadv_hard_iface *primary_if,
1079 struct sk_buff *skb)
1080 {
1081 struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
1082 u8 *hw_src, *hw_dst;
1083 struct vlan_hdr *vhdr, vhdr_buf;
1084 struct ethhdr *ethhdr;
1085 struct arphdr *arphdr;
1086 unsigned short vid;
1087 int vlan_depth = 0;
1088 __be16 proto;
1089 int headlen;
1090 int ret;
1091
1092 vid = batadv_get_vid(skb, 0);
1093 ethhdr = eth_hdr(skb);
1094
1095 proto = ethhdr->h_proto;
1096 headlen = ETH_HLEN;
1097 if (vid & BATADV_VLAN_HAS_TAG) {
1098 /* Traverse the VLAN/Ethertypes.
1099 *
1100 * At this point it is known that the first protocol is a VLAN
1101 * header, so start checking at the encapsulated protocol.
1102 *
1103 * The depth of the VLAN headers is recorded to drop BLA claim
1104 * frames encapsulated into multiple VLAN headers (QinQ).
1105 */
1106 do {
1107 vhdr = skb_header_pointer(skb, headlen, VLAN_HLEN,
1108 &vhdr_buf);
1109 if (!vhdr)
1110 return false;
1111
1112 proto = vhdr->h_vlan_encapsulated_proto;
1113 headlen += VLAN_HLEN;
1114 vlan_depth++;
1115 } while (proto == htons(ETH_P_8021Q));
1116 }
1117
1118 if (proto != htons(ETH_P_ARP))
1119 return false; /* not a claim frame */
1120
1121 /* this must be a ARP frame. check if it is a claim. */
1122
1123 if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev))))
1124 return false;
1125
1126 /* pskb_may_pull() may have modified the pointers, get ethhdr again */
1127 ethhdr = eth_hdr(skb);
1128 arphdr = (struct arphdr *)((u8 *)ethhdr + headlen);
1129
1130 /* Check whether the ARP frame carries a valid
1131 * IP information
1132 */
1133 if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
1134 return false;
1135 if (arphdr->ar_pro != htons(ETH_P_IP))
1136 return false;
1137 if (arphdr->ar_hln != ETH_ALEN)
1138 return false;
1139 if (arphdr->ar_pln != 4)
1140 return false;
1141
1142 hw_src = (u8 *)arphdr + sizeof(struct arphdr);
1143 hw_dst = hw_src + ETH_ALEN + 4;
1144 bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
1145 bla_dst_own = &bat_priv->bla.claim_dest;
1146
1147 /* check if it is a claim frame in general */
1148 if (memcmp(bla_dst->magic, bla_dst_own->magic,
1149 sizeof(bla_dst->magic)) != 0)
1150 return false;
1151
1152 /* check if there is a claim frame encapsulated deeper in (QinQ) and
1153 * drop that, as this is not supported by BLA but should also not be
1154 * sent via the mesh.
1155 */
1156 if (vlan_depth > 1)
1157 return true;
1158
1159 /* Let the loopdetect frames on the mesh in any case. */
1160 if (bla_dst->type == BATADV_CLAIM_TYPE_LOOPDETECT)
1161 return false;
1162
1163 /* check if it is a claim frame. */
1164 ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst,
1165 ethhdr);
1166 if (ret == 1)
1167 batadv_dbg(BATADV_DBG_BLA, bat_priv,
1168 "%s(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
1169 __func__, ethhdr->h_source, batadv_print_vid(vid),
1170 hw_src, hw_dst);
1171
1172 if (ret < 2)
1173 return !!ret;
1174
1175 /* become a backbone gw ourselves on this vlan if not happened yet */
1176 batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1177
1178 /* check for the different types of claim frames ... */
1179 switch (bla_dst->type) {
1180 case BATADV_CLAIM_TYPE_CLAIM:
1181 if (batadv_handle_claim(bat_priv, primary_if, hw_src,
1182 ethhdr->h_source, vid))
1183 return true;
1184 break;
1185 case BATADV_CLAIM_TYPE_UNCLAIM:
1186 if (batadv_handle_unclaim(bat_priv, primary_if,
1187 ethhdr->h_source, hw_src, vid))
1188 return true;
1189 break;
1190
1191 case BATADV_CLAIM_TYPE_ANNOUNCE:
1192 if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source,
1193 vid))
1194 return true;
1195 break;
1196 case BATADV_CLAIM_TYPE_REQUEST:
1197 if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr,
1198 vid))
1199 return true;
1200 break;
1201 }
1202
1203 batadv_dbg(BATADV_DBG_BLA, bat_priv,
1204 "%s(): ERROR - this looks like a claim frame, but is useless. eth src %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
1205 __func__, ethhdr->h_source, batadv_print_vid(vid), hw_src,
1206 hw_dst);
1207 return true;
1208 }
1209
1210 /**
1211 * batadv_bla_purge_backbone_gw() - Remove backbone gateways after a timeout or
1212 * immediately
1213 * @bat_priv: the bat priv with all the soft interface information
1214 * @now: whether the whole hash shall be wiped now
1215 *
1216 * Check when we last heard from other nodes, and remove them in case of
1217 * a time out, or clean all backbone gws if now is set.
1218 */
1219 static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now)
1220 {
1221 struct batadv_bla_backbone_gw *backbone_gw;
1222 struct hlist_node *node_tmp;
1223 struct hlist_head *head;
1224 struct batadv_hashtable *hash;
1225 spinlock_t *list_lock; /* protects write access to the hash lists */
1226 int i;
1227
1228 hash = bat_priv->bla.backbone_hash;
1229 if (!hash)
1230 return;
1231
1232 for (i = 0; i < hash->size; i++) {
1233 head = &hash->table[i];
1234 list_lock = &hash->list_locks[i];
1235
1236 spin_lock_bh(list_lock);
1237 hlist_for_each_entry_safe(backbone_gw, node_tmp,
1238 head, hash_entry) {
1239 if (now)
1240 goto purge_now;
1241 if (!batadv_has_timed_out(backbone_gw->lasttime,
1242 BATADV_BLA_BACKBONE_TIMEOUT))
1243 continue;
1244
1245 batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
1246 "%s(): backbone gw %pM timed out\n",
1247 __func__, backbone_gw->orig);
1248
1249 purge_now:
1250 /* don't wait for the pending request anymore */
1251 if (atomic_read(&backbone_gw->request_sent))
1252 atomic_dec(&bat_priv->bla.num_requests);
1253
1254 batadv_bla_del_backbone_claims(backbone_gw);
1255
1256 hlist_del_rcu(&backbone_gw->hash_entry);
1257 batadv_backbone_gw_put(backbone_gw);
1258 }
1259 spin_unlock_bh(list_lock);
1260 }
1261 }
1262
1263 /**
1264 * batadv_bla_purge_claims() - Remove claims after a timeout or immediately
1265 * @bat_priv: the bat priv with all the soft interface information
1266 * @primary_if: the selected primary interface, may be NULL if now is set
1267 * @now: whether the whole hash shall be wiped now
1268 *
1269 * Check when we heard last time from our own claims, and remove them in case of
1270 * a time out, or clean all claims if now is set
1271 */
1272 static void batadv_bla_purge_claims(struct batadv_priv *bat_priv,
1273 struct batadv_hard_iface *primary_if,
1274 int now)
1275 {
1276 struct batadv_bla_backbone_gw *backbone_gw;
1277 struct batadv_bla_claim *claim;
1278 struct hlist_head *head;
1279 struct batadv_hashtable *hash;
1280 int i;
1281
1282 hash = bat_priv->bla.claim_hash;
1283 if (!hash)
1284 return;
1285
1286 for (i = 0; i < hash->size; i++) {
1287 head = &hash->table[i];
1288
1289 rcu_read_lock();
1290 hlist_for_each_entry_rcu(claim, head, hash_entry) {
1291 backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
1292 if (now)
1293 goto purge_now;
1294
1295 if (!batadv_compare_eth(backbone_gw->orig,
1296 primary_if->net_dev->dev_addr))
1297 goto skip;
1298
1299 if (!batadv_has_timed_out(claim->lasttime,
1300 BATADV_BLA_CLAIM_TIMEOUT))
1301 goto skip;
1302
1303 batadv_dbg(BATADV_DBG_BLA, bat_priv,
1304 "%s(): timed out.\n", __func__);
1305
1306 purge_now:
1307 batadv_dbg(BATADV_DBG_BLA, bat_priv,
1308 "%s(): %pM, vid %d\n", __func__,
1309 claim->addr, claim->vid);
1310
1311 batadv_handle_unclaim(bat_priv, primary_if,
1312 backbone_gw->orig,
1313 claim->addr, claim->vid);
1314 skip:
1315 batadv_backbone_gw_put(backbone_gw);
1316 }
1317 rcu_read_unlock();
1318 }
1319 }
1320
1321 /**
1322 * batadv_bla_update_orig_address() - Update the backbone gateways when the own
1323 * originator address changes
1324 * @bat_priv: the bat priv with all the soft interface information
1325 * @primary_if: the new selected primary_if
1326 * @oldif: the old primary interface, may be NULL
1327 */
1328 void batadv_bla_update_orig_address(struct batadv_priv *bat_priv,
1329 struct batadv_hard_iface *primary_if,
1330 struct batadv_hard_iface *oldif)
1331 {
1332 struct batadv_bla_backbone_gw *backbone_gw;
1333 struct hlist_head *head;
1334 struct batadv_hashtable *hash;
1335 __be16 group;
1336 int i;
1337
1338 /* reset bridge loop avoidance group id */
1339 group = htons(crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN));
1340 bat_priv->bla.claim_dest.group = group;
1341
1342 /* purge everything when bridge loop avoidance is turned off */
1343 if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1344 oldif = NULL;
1345
1346 if (!oldif) {
1347 batadv_bla_purge_claims(bat_priv, NULL, 1);
1348 batadv_bla_purge_backbone_gw(bat_priv, 1);
1349 return;
1350 }
1351
1352 hash = bat_priv->bla.backbone_hash;
1353 if (!hash)
1354 return;
1355
1356 for (i = 0; i < hash->size; i++) {
1357 head = &hash->table[i];
1358
1359 rcu_read_lock();
1360 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1361 /* own orig still holds the old value. */
1362 if (!batadv_compare_eth(backbone_gw->orig,
1363 oldif->net_dev->dev_addr))
1364 continue;
1365
1366 ether_addr_copy(backbone_gw->orig,
1367 primary_if->net_dev->dev_addr);
1368 /* send an announce frame so others will ask for our
1369 * claims and update their tables.
1370 */
1371 batadv_bla_send_announce(bat_priv, backbone_gw);
1372 }
1373 rcu_read_unlock();
1374 }
1375 }
1376
1377 /**
1378 * batadv_bla_send_loopdetect() - send a loopdetect frame
1379 * @bat_priv: the bat priv with all the soft interface information
1380 * @backbone_gw: the backbone gateway for which a loop should be detected
1381 *
1382 * To detect loops that the bridge loop avoidance can't handle, send a loop
1383 * detection packet on the backbone. Unlike other BLA frames, this frame will
1384 * be allowed on the mesh by other nodes. If it is received on the mesh, this
1385 * indicates that there is a loop.
1386 */
1387 static void
1388 batadv_bla_send_loopdetect(struct batadv_priv *bat_priv,
1389 struct batadv_bla_backbone_gw *backbone_gw)
1390 {
1391 batadv_dbg(BATADV_DBG_BLA, bat_priv, "Send loopdetect frame for vid %d\n",
1392 backbone_gw->vid);
1393 batadv_bla_send_claim(bat_priv, bat_priv->bla.loopdetect_addr,
1394 backbone_gw->vid, BATADV_CLAIM_TYPE_LOOPDETECT);
1395 }
1396
1397 /**
1398 * batadv_bla_status_update() - purge bla interfaces if necessary
1399 * @net_dev: the soft interface net device
1400 */
1401 void batadv_bla_status_update(struct net_device *net_dev)
1402 {
1403 struct batadv_priv *bat_priv = netdev_priv(net_dev);
1404 struct batadv_hard_iface *primary_if;
1405
1406 primary_if = batadv_primary_if_get_selected(bat_priv);
1407 if (!primary_if)
1408 return;
1409
1410 /* this function already purges everything when bla is disabled,
1411 * so just call that one.
1412 */
1413 batadv_bla_update_orig_address(bat_priv, primary_if, primary_if);
1414 batadv_hardif_put(primary_if);
1415 }
1416
1417 /**
1418 * batadv_bla_periodic_work() - performs periodic bla work
1419 * @work: kernel work struct
1420 *
1421 * periodic work to do:
1422 * * purge structures when they are too old
1423 * * send announcements
1424 */
1425 static void batadv_bla_periodic_work(struct work_struct *work)
1426 {
1427 struct delayed_work *delayed_work;
1428 struct batadv_priv *bat_priv;
1429 struct batadv_priv_bla *priv_bla;
1430 struct hlist_head *head;
1431 struct batadv_bla_backbone_gw *backbone_gw;
1432 struct batadv_hashtable *hash;
1433 struct batadv_hard_iface *primary_if;
1434 bool send_loopdetect = false;
1435 int i;
1436
1437 delayed_work = to_delayed_work(work);
1438 priv_bla = container_of(delayed_work, struct batadv_priv_bla, work);
1439 bat_priv = container_of(priv_bla, struct batadv_priv, bla);
1440 primary_if = batadv_primary_if_get_selected(bat_priv);
1441 if (!primary_if)
1442 goto out;
1443
1444 batadv_bla_purge_claims(bat_priv, primary_if, 0);
1445 batadv_bla_purge_backbone_gw(bat_priv, 0);
1446
1447 if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1448 goto out;
1449
1450 if (atomic_dec_and_test(&bat_priv->bla.loopdetect_next)) {
1451 /* set a new random mac address for the next bridge loop
1452 * detection frames. Set the locally administered bit to avoid
1453 * collisions with users mac addresses.
1454 */
1455 eth_random_addr(bat_priv->bla.loopdetect_addr);
1456 bat_priv->bla.loopdetect_addr[0] = 0xba;
1457 bat_priv->bla.loopdetect_addr[1] = 0xbe;
1458 bat_priv->bla.loopdetect_lasttime = jiffies;
1459 atomic_set(&bat_priv->bla.loopdetect_next,
1460 BATADV_BLA_LOOPDETECT_PERIODS);
1461
1462 /* mark for sending loop detect on all VLANs */
1463 send_loopdetect = true;
1464 }
1465
1466 hash = bat_priv->bla.backbone_hash;
1467 if (!hash)
1468 goto out;
1469
1470 for (i = 0; i < hash->size; i++) {
1471 head = &hash->table[i];
1472
1473 rcu_read_lock();
1474 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1475 if (!batadv_compare_eth(backbone_gw->orig,
1476 primary_if->net_dev->dev_addr))
1477 continue;
1478
1479 backbone_gw->lasttime = jiffies;
1480
1481 batadv_bla_send_announce(bat_priv, backbone_gw);
1482 if (send_loopdetect)
1483 batadv_bla_send_loopdetect(bat_priv,
1484 backbone_gw);
1485
1486 /* request_sent is only set after creation to avoid
1487 * problems when we are not yet known as backbone gw
1488 * in the backbone.
1489 *
1490 * We can reset this now after we waited some periods
1491 * to give bridge forward delays and bla group forming
1492 * some grace time.
1493 */
1494
1495 if (atomic_read(&backbone_gw->request_sent) == 0)
1496 continue;
1497
1498 if (!atomic_dec_and_test(&backbone_gw->wait_periods))
1499 continue;
1500
1501 atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
1502 atomic_set(&backbone_gw->request_sent, 0);
1503 }
1504 rcu_read_unlock();
1505 }
1506 out:
1507 batadv_hardif_put(primary_if);
1508
1509 queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
1510 msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
1511 }
1512
1513 /* The hash for claim and backbone hash receive the same key because they
1514 * are getting initialized by hash_new with the same key. Reinitializing
1515 * them with to different keys to allow nested locking without generating
1516 * lockdep warnings
1517 */
1518 static struct lock_class_key batadv_claim_hash_lock_class_key;
1519 static struct lock_class_key batadv_backbone_hash_lock_class_key;
1520
1521 /**
1522 * batadv_bla_init() - initialize all bla structures
1523 * @bat_priv: the bat priv with all the soft interface information
1524 *
1525 * Return: 0 on success, < 0 on error.
1526 */
1527 int batadv_bla_init(struct batadv_priv *bat_priv)
1528 {
1529 int i;
1530 u8 claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00};
1531 struct batadv_hard_iface *primary_if;
1532 u16 crc;
1533 unsigned long entrytime;
1534
1535 spin_lock_init(&bat_priv->bla.bcast_duplist_lock);
1536
1537 batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n");
1538
1539 /* setting claim destination address */
1540 memcpy(&bat_priv->bla.claim_dest.magic, claim_dest, 3);
1541 bat_priv->bla.claim_dest.type = 0;
1542 primary_if = batadv_primary_if_get_selected(bat_priv);
1543 if (primary_if) {
1544 crc = crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN);
1545 bat_priv->bla.claim_dest.group = htons(crc);
1546 batadv_hardif_put(primary_if);
1547 } else {
1548 bat_priv->bla.claim_dest.group = 0; /* will be set later */
1549 }
1550
1551 /* initialize the duplicate list */
1552 entrytime = jiffies - msecs_to_jiffies(BATADV_DUPLIST_TIMEOUT);
1553 for (i = 0; i < BATADV_DUPLIST_SIZE; i++)
1554 bat_priv->bla.bcast_duplist[i].entrytime = entrytime;
1555 bat_priv->bla.bcast_duplist_curr = 0;
1556
1557 atomic_set(&bat_priv->bla.loopdetect_next,
1558 BATADV_BLA_LOOPDETECT_PERIODS);
1559
1560 if (bat_priv->bla.claim_hash)
1561 return 0;
1562
1563 bat_priv->bla.claim_hash = batadv_hash_new(128);
1564 if (!bat_priv->bla.claim_hash)
1565 return -ENOMEM;
1566
1567 bat_priv->bla.backbone_hash = batadv_hash_new(32);
1568 if (!bat_priv->bla.backbone_hash) {
1569 batadv_hash_destroy(bat_priv->bla.claim_hash);
1570 return -ENOMEM;
1571 }
1572
1573 batadv_hash_set_lock_class(bat_priv->bla.claim_hash,
1574 &batadv_claim_hash_lock_class_key);
1575 batadv_hash_set_lock_class(bat_priv->bla.backbone_hash,
1576 &batadv_backbone_hash_lock_class_key);
1577
1578 batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hashes initialized\n");
1579
1580 INIT_DELAYED_WORK(&bat_priv->bla.work, batadv_bla_periodic_work);
1581
1582 queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
1583 msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
1584 return 0;
1585 }
1586
1587 /**
1588 * batadv_bla_check_duplist() - Check if a frame is in the broadcast dup.
1589 * @bat_priv: the bat priv with all the soft interface information
1590 * @skb: contains the multicast packet to be checked
1591 * @payload_ptr: pointer to position inside the head buffer of the skb
1592 * marking the start of the data to be CRC'ed
1593 * @orig: originator mac address, NULL if unknown
1594 *
1595 * Check if it is on our broadcast list. Another gateway might have sent the
1596 * same packet because it is connected to the same backbone, so we have to
1597 * remove this duplicate.
1598 *
1599 * This is performed by checking the CRC, which will tell us
1600 * with a good chance that it is the same packet. If it is furthermore
1601 * sent by another host, drop it. We allow equal packets from
1602 * the same host however as this might be intended.
1603 *
1604 * Return: true if a packet is in the duplicate list, false otherwise.
1605 */
1606 static bool batadv_bla_check_duplist(struct batadv_priv *bat_priv,
1607 struct sk_buff *skb, u8 *payload_ptr,
1608 const u8 *orig)
1609 {
1610 struct batadv_bcast_duplist_entry *entry;
1611 bool ret = false;
1612 int i, curr;
1613 __be32 crc;
1614
1615 /* calculate the crc ... */
1616 crc = batadv_skb_crc32(skb, payload_ptr);
1617
1618 spin_lock_bh(&bat_priv->bla.bcast_duplist_lock);
1619
1620 for (i = 0; i < BATADV_DUPLIST_SIZE; i++) {
1621 curr = (bat_priv->bla.bcast_duplist_curr + i);
1622 curr %= BATADV_DUPLIST_SIZE;
1623 entry = &bat_priv->bla.bcast_duplist[curr];
1624
1625 /* we can stop searching if the entry is too old ;
1626 * later entries will be even older
1627 */
1628 if (batadv_has_timed_out(entry->entrytime,
1629 BATADV_DUPLIST_TIMEOUT))
1630 break;
1631
1632 if (entry->crc != crc)
1633 continue;
1634
1635 /* are the originators both known and not anonymous? */
1636 if (orig && !is_zero_ether_addr(orig) &&
1637 !is_zero_ether_addr(entry->orig)) {
1638 /* If known, check if the new frame came from
1639 * the same originator:
1640 * We are safe to take identical frames from the
1641 * same orig, if known, as multiplications in
1642 * the mesh are detected via the (orig, seqno) pair.
1643 * So we can be a bit more liberal here and allow
1644 * identical frames from the same orig which the source
1645 * host might have sent multiple times on purpose.
1646 */
1647 if (batadv_compare_eth(entry->orig, orig))
1648 continue;
1649 }
1650
1651 /* this entry seems to match: same crc, not too old,
1652 * and from another gw. therefore return true to forbid it.
1653 */
1654 ret = true;
1655 goto out;
1656 }
1657 /* not found, add a new entry (overwrite the oldest entry)
1658 * and allow it, its the first occurrence.
1659 */
1660 curr = (bat_priv->bla.bcast_duplist_curr + BATADV_DUPLIST_SIZE - 1);
1661 curr %= BATADV_DUPLIST_SIZE;
1662 entry = &bat_priv->bla.bcast_duplist[curr];
1663 entry->crc = crc;
1664 entry->entrytime = jiffies;
1665
1666 /* known originator */
1667 if (orig)
1668 ether_addr_copy(entry->orig, orig);
1669 /* anonymous originator */
1670 else
1671 eth_zero_addr(entry->orig);
1672
1673 bat_priv->bla.bcast_duplist_curr = curr;
1674
1675 out:
1676 spin_unlock_bh(&bat_priv->bla.bcast_duplist_lock);
1677
1678 return ret;
1679 }
1680
1681 /**
1682 * batadv_bla_check_ucast_duplist() - Check if a frame is in the broadcast dup.
1683 * @bat_priv: the bat priv with all the soft interface information
1684 * @skb: contains the multicast packet to be checked, decapsulated from a
1685 * unicast_packet
1686 *
1687 * Check if it is on our broadcast list. Another gateway might have sent the
1688 * same packet because it is connected to the same backbone, so we have to
1689 * remove this duplicate.
1690 *
1691 * Return: true if a packet is in the duplicate list, false otherwise.
1692 */
1693 static bool batadv_bla_check_ucast_duplist(struct batadv_priv *bat_priv,
1694 struct sk_buff *skb)
1695 {
1696 return batadv_bla_check_duplist(bat_priv, skb, (u8 *)skb->data, NULL);
1697 }
1698
1699 /**
1700 * batadv_bla_check_bcast_duplist() - Check if a frame is in the broadcast dup.
1701 * @bat_priv: the bat priv with all the soft interface information
1702 * @skb: contains the bcast_packet to be checked
1703 *
1704 * Check if it is on our broadcast list. Another gateway might have sent the
1705 * same packet because it is connected to the same backbone, so we have to
1706 * remove this duplicate.
1707 *
1708 * Return: true if a packet is in the duplicate list, false otherwise.
1709 */
1710 bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
1711 struct sk_buff *skb)
1712 {
1713 struct batadv_bcast_packet *bcast_packet;
1714 u8 *payload_ptr;
1715
1716 bcast_packet = (struct batadv_bcast_packet *)skb->data;
1717 payload_ptr = (u8 *)(bcast_packet + 1);
1718
1719 return batadv_bla_check_duplist(bat_priv, skb, payload_ptr,
1720 bcast_packet->orig);
1721 }
1722
1723 /**
1724 * batadv_bla_is_backbone_gw_orig() - Check if the originator is a gateway for
1725 * the VLAN identified by vid.
1726 * @bat_priv: the bat priv with all the soft interface information
1727 * @orig: originator mac address
1728 * @vid: VLAN identifier
1729 *
1730 * Return: true if orig is a backbone for this vid, false otherwise.
1731 */
1732 bool batadv_bla_is_backbone_gw_orig(struct batadv_priv *bat_priv, u8 *orig,
1733 unsigned short vid)
1734 {
1735 struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
1736 struct hlist_head *head;
1737 struct batadv_bla_backbone_gw *backbone_gw;
1738 int i;
1739
1740 if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1741 return false;
1742
1743 if (!hash)
1744 return false;
1745
1746 for (i = 0; i < hash->size; i++) {
1747 head = &hash->table[i];
1748
1749 rcu_read_lock();
1750 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1751 if (batadv_compare_eth(backbone_gw->orig, orig) &&
1752 backbone_gw->vid == vid) {
1753 rcu_read_unlock();
1754 return true;
1755 }
1756 }
1757 rcu_read_unlock();
1758 }
1759
1760 return false;
1761 }
1762
1763 /**
1764 * batadv_bla_is_backbone_gw() - check if originator is a backbone gw for a VLAN
1765 * @skb: the frame to be checked
1766 * @orig_node: the orig_node of the frame
1767 * @hdr_size: maximum length of the frame
1768 *
1769 * Return: true if the orig_node is also a gateway on the soft interface,
1770 * otherwise it returns false.
1771 */
1772 bool batadv_bla_is_backbone_gw(struct sk_buff *skb,
1773 struct batadv_orig_node *orig_node, int hdr_size)
1774 {
1775 struct batadv_bla_backbone_gw *backbone_gw;
1776 unsigned short vid;
1777
1778 if (!atomic_read(&orig_node->bat_priv->bridge_loop_avoidance))
1779 return false;
1780
1781 /* first, find out the vid. */
1782 if (!pskb_may_pull(skb, hdr_size + ETH_HLEN))
1783 return false;
1784
1785 vid = batadv_get_vid(skb, hdr_size);
1786
1787 /* see if this originator is a backbone gw for this VLAN */
1788 backbone_gw = batadv_backbone_hash_find(orig_node->bat_priv,
1789 orig_node->orig, vid);
1790 if (!backbone_gw)
1791 return false;
1792
1793 batadv_backbone_gw_put(backbone_gw);
1794 return true;
1795 }
1796
1797 /**
1798 * batadv_bla_free() - free all bla structures
1799 * @bat_priv: the bat priv with all the soft interface information
1800 *
1801 * for softinterface free or module unload
1802 */
1803 void batadv_bla_free(struct batadv_priv *bat_priv)
1804 {
1805 struct batadv_hard_iface *primary_if;
1806
1807 cancel_delayed_work_sync(&bat_priv->bla.work);
1808 primary_if = batadv_primary_if_get_selected(bat_priv);
1809
1810 if (bat_priv->bla.claim_hash) {
1811 batadv_bla_purge_claims(bat_priv, primary_if, 1);
1812 batadv_hash_destroy(bat_priv->bla.claim_hash);
1813 bat_priv->bla.claim_hash = NULL;
1814 }
1815 if (bat_priv->bla.backbone_hash) {
1816 batadv_bla_purge_backbone_gw(bat_priv, 1);
1817 batadv_hash_destroy(bat_priv->bla.backbone_hash);
1818 bat_priv->bla.backbone_hash = NULL;
1819 }
1820 batadv_hardif_put(primary_if);
1821 }
1822
1823 /**
1824 * batadv_bla_loopdetect_check() - check and handle a detected loop
1825 * @bat_priv: the bat priv with all the soft interface information
1826 * @skb: the packet to check
1827 * @primary_if: interface where the request came on
1828 * @vid: the VLAN ID of the frame
1829 *
1830 * Checks if this packet is a loop detect frame which has been sent by us,
1831 * throws an uevent and logs the event if that is the case.
1832 *
1833 * Return: true if it is a loop detect frame which is to be dropped, false
1834 * otherwise.
1835 */
1836 static bool
1837 batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb,
1838 struct batadv_hard_iface *primary_if,
1839 unsigned short vid)
1840 {
1841 struct batadv_bla_backbone_gw *backbone_gw;
1842 struct ethhdr *ethhdr;
1843 bool ret;
1844
1845 ethhdr = eth_hdr(skb);
1846
1847 /* Only check for the MAC address and skip more checks here for
1848 * performance reasons - this function is on the hotpath, after all.
1849 */
1850 if (!batadv_compare_eth(ethhdr->h_source,
1851 bat_priv->bla.loopdetect_addr))
1852 return false;
1853
1854 /* If the packet came too late, don't forward it on the mesh
1855 * but don't consider that as loop. It might be a coincidence.
1856 */
1857 if (batadv_has_timed_out(bat_priv->bla.loopdetect_lasttime,
1858 BATADV_BLA_LOOPDETECT_TIMEOUT))
1859 return true;
1860
1861 backbone_gw = batadv_bla_get_backbone_gw(bat_priv,
1862 primary_if->net_dev->dev_addr,
1863 vid, true);
1864 if (unlikely(!backbone_gw))
1865 return true;
1866
1867 ret = queue_work(batadv_event_workqueue, &backbone_gw->report_work);
1868
1869 /* backbone_gw is unreferenced in the report work function
1870 * if queue_work() call was successful
1871 */
1872 if (!ret)
1873 batadv_backbone_gw_put(backbone_gw);
1874
1875 return true;
1876 }
1877
1878 /**
1879 * batadv_bla_rx() - check packets coming from the mesh.
1880 * @bat_priv: the bat priv with all the soft interface information
1881 * @skb: the frame to be checked
1882 * @vid: the VLAN ID of the frame
1883 * @packet_type: the batman packet type this frame came in
1884 *
1885 * batadv_bla_rx avoidance checks if:
1886 * * we have to race for a claim
1887 * * if the frame is allowed on the LAN
1888 *
1889 * In these cases, the skb is further handled by this function
1890 *
1891 * Return: true if handled, otherwise it returns false and the caller shall
1892 * further process the skb.
1893 */
1894 bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
1895 unsigned short vid, int packet_type)
1896 {
1897 struct batadv_bla_backbone_gw *backbone_gw;
1898 struct ethhdr *ethhdr;
1899 struct batadv_bla_claim search_claim, *claim = NULL;
1900 struct batadv_hard_iface *primary_if;
1901 bool own_claim;
1902 bool ret;
1903
1904 ethhdr = eth_hdr(skb);
1905
1906 primary_if = batadv_primary_if_get_selected(bat_priv);
1907 if (!primary_if)
1908 goto handled;
1909
1910 if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1911 goto allow;
1912
1913 if (batadv_bla_loopdetect_check(bat_priv, skb, primary_if, vid))
1914 goto handled;
1915
1916 if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
1917 /* don't allow multicast packets while requests are in flight */
1918 if (is_multicast_ether_addr(ethhdr->h_dest))
1919 /* Both broadcast flooding or multicast-via-unicasts
1920 * delivery might send to multiple backbone gateways
1921 * sharing the same LAN and therefore need to coordinate
1922 * which backbone gateway forwards into the LAN,
1923 * by claiming the payload source address.
1924 *
1925 * Broadcast flooding and multicast-via-unicasts
1926 * delivery use the following two batman packet types.
1927 * Note: explicitly exclude BATADV_UNICAST_4ADDR,
1928 * as the DHCP gateway feature will send explicitly
1929 * to only one BLA gateway, so the claiming process
1930 * should be avoided there.
1931 */
1932 if (packet_type == BATADV_BCAST ||
1933 packet_type == BATADV_UNICAST)
1934 goto handled;
1935
1936 /* potential duplicates from foreign BLA backbone gateways via
1937 * multicast-in-unicast packets
1938 */
1939 if (is_multicast_ether_addr(ethhdr->h_dest) &&
1940 packet_type == BATADV_UNICAST &&
1941 batadv_bla_check_ucast_duplist(bat_priv, skb))
1942 goto handled;
1943
1944 ether_addr_copy(search_claim.addr, ethhdr->h_source);
1945 search_claim.vid = vid;
1946 claim = batadv_claim_hash_find(bat_priv, &search_claim);
1947
1948 if (!claim) {
1949 /* possible optimization: race for a claim */
1950 /* No claim exists yet, claim it for us!
1951 */
1952
1953 batadv_dbg(BATADV_DBG_BLA, bat_priv,
1954 "%s(): Unclaimed MAC %pM found. Claim it. Local: %s\n",
1955 __func__, ethhdr->h_source,
1956 batadv_is_my_client(bat_priv,
1957 ethhdr->h_source, vid) ?
1958 "yes" : "no");
1959 batadv_handle_claim(bat_priv, primary_if,
1960 primary_if->net_dev->dev_addr,
1961 ethhdr->h_source, vid);
1962 goto allow;
1963 }
1964
1965 /* if it is our own claim ... */
1966 backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
1967 own_claim = batadv_compare_eth(backbone_gw->orig,
1968 primary_if->net_dev->dev_addr);
1969 batadv_backbone_gw_put(backbone_gw);
1970
1971 if (own_claim) {
1972 /* ... allow it in any case */
1973 claim->lasttime = jiffies;
1974 goto allow;
1975 }
1976
1977 /* if it is a multicast ... */
1978 if (is_multicast_ether_addr(ethhdr->h_dest) &&
1979 (packet_type == BATADV_BCAST || packet_type == BATADV_UNICAST)) {
1980 /* ... drop it. the responsible gateway is in charge.
1981 *
1982 * We need to check packet type because with the gateway
1983 * feature, broadcasts (like DHCP requests) may be sent
1984 * using a unicast 4 address packet type. See comment above.
1985 */
1986 goto handled;
1987 } else {
1988 /* seems the client considers us as its best gateway.
1989 * send a claim and update the claim table
1990 * immediately.
1991 */
1992 batadv_handle_claim(bat_priv, primary_if,
1993 primary_if->net_dev->dev_addr,
1994 ethhdr->h_source, vid);
1995 goto allow;
1996 }
1997 allow:
1998 batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1999 ret = false;
2000 goto out;
2001
2002 handled:
2003 kfree_skb(skb);
2004 ret = true;
2005
2006 out:
2007 batadv_hardif_put(primary_if);
2008 batadv_claim_put(claim);
2009 return ret;
2010 }
2011
2012 /**
2013 * batadv_bla_tx() - check packets going into the mesh
2014 * @bat_priv: the bat priv with all the soft interface information
2015 * @skb: the frame to be checked
2016 * @vid: the VLAN ID of the frame
2017 *
2018 * batadv_bla_tx checks if:
2019 * * a claim was received which has to be processed
2020 * * the frame is allowed on the mesh
2021 *
2022 * in these cases, the skb is further handled by this function.
2023 *
2024 * This call might reallocate skb data.
2025 *
2026 * Return: true if handled, otherwise it returns false and the caller shall
2027 * further process the skb.
2028 */
2029 bool batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb,
2030 unsigned short vid)
2031 {
2032 struct ethhdr *ethhdr;
2033 struct batadv_bla_claim search_claim, *claim = NULL;
2034 struct batadv_bla_backbone_gw *backbone_gw;
2035 struct batadv_hard_iface *primary_if;
2036 bool client_roamed;
2037 bool ret = false;
2038
2039 primary_if = batadv_primary_if_get_selected(bat_priv);
2040 if (!primary_if)
2041 goto out;
2042
2043 if (!atomic_read(&bat_priv->bridge_loop_avoidance))
2044 goto allow;
2045
2046 if (batadv_bla_process_claim(bat_priv, primary_if, skb))
2047 goto handled;
2048
2049 ethhdr = eth_hdr(skb);
2050
2051 if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
2052 /* don't allow broadcasts while requests are in flight */
2053 if (is_multicast_ether_addr(ethhdr->h_dest))
2054 goto handled;
2055
2056 ether_addr_copy(search_claim.addr, ethhdr->h_source);
2057 search_claim.vid = vid;
2058
2059 claim = batadv_claim_hash_find(bat_priv, &search_claim);
2060
2061 /* if no claim exists, allow it. */
2062 if (!claim)
2063 goto allow;
2064
2065 /* check if we are responsible. */
2066 backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
2067 client_roamed = batadv_compare_eth(backbone_gw->orig,
2068 primary_if->net_dev->dev_addr);
2069 batadv_backbone_gw_put(backbone_gw);
2070
2071 if (client_roamed) {
2072 /* if yes, the client has roamed and we have
2073 * to unclaim it.
2074 */
2075 if (batadv_has_timed_out(claim->lasttime, 100)) {
2076 /* only unclaim if the last claim entry is
2077 * older than 100 ms to make sure we really
2078 * have a roaming client here.
2079 */
2080 batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): Roaming client %pM detected. Unclaim it.\n",
2081 __func__, ethhdr->h_source);
2082 batadv_handle_unclaim(bat_priv, primary_if,
2083 primary_if->net_dev->dev_addr,
2084 ethhdr->h_source, vid);
2085 goto allow;
2086 } else {
2087 batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): Race for claim %pM detected. Drop packet.\n",
2088 __func__, ethhdr->h_source);
2089 goto handled;
2090 }
2091 }
2092
2093 /* check if it is a multicast/broadcast frame */
2094 if (is_multicast_ether_addr(ethhdr->h_dest)) {
2095 /* drop it. the responsible gateway has forwarded it into
2096 * the backbone network.
2097 */
2098 goto handled;
2099 } else {
2100 /* we must allow it. at least if we are
2101 * responsible for the DESTINATION.
2102 */
2103 goto allow;
2104 }
2105 allow:
2106 batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
2107 ret = false;
2108 goto out;
2109 handled:
2110 ret = true;
2111 out:
2112 batadv_hardif_put(primary_if);
2113 batadv_claim_put(claim);
2114 return ret;
2115 }
2116
2117 /**
2118 * batadv_bla_claim_dump_entry() - dump one entry of the claim table
2119 * to a netlink socket
2120 * @msg: buffer for the message
2121 * @portid: netlink port
2122 * @cb: Control block containing additional options
2123 * @primary_if: primary interface
2124 * @claim: entry to dump
2125 *
2126 * Return: 0 or error code.
2127 */
2128 static int
2129 batadv_bla_claim_dump_entry(struct sk_buff *msg, u32 portid,
2130 struct netlink_callback *cb,
2131 struct batadv_hard_iface *primary_if,
2132 struct batadv_bla_claim *claim)
2133 {
2134 const u8 *primary_addr = primary_if->net_dev->dev_addr;
2135 u16 backbone_crc;
2136 bool is_own;
2137 void *hdr;
2138 int ret = -EINVAL;
2139
2140 hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq,
2141 &batadv_netlink_family, NLM_F_MULTI,
2142 BATADV_CMD_GET_BLA_CLAIM);
2143 if (!hdr) {
2144 ret = -ENOBUFS;
2145 goto out;
2146 }
2147
2148 genl_dump_check_consistent(cb, hdr);
2149
2150 is_own = batadv_compare_eth(claim->backbone_gw->orig,
2151 primary_addr);
2152
2153 spin_lock_bh(&claim->backbone_gw->crc_lock);
2154 backbone_crc = claim->backbone_gw->crc;
2155 spin_unlock_bh(&claim->backbone_gw->crc_lock);
2156
2157 if (is_own)
2158 if (nla_put_flag(msg, BATADV_ATTR_BLA_OWN)) {
2159 genlmsg_cancel(msg, hdr);
2160 goto out;
2161 }
2162
2163 if (nla_put(msg, BATADV_ATTR_BLA_ADDRESS, ETH_ALEN, claim->addr) ||
2164 nla_put_u16(msg, BATADV_ATTR_BLA_VID, claim->vid) ||
2165 nla_put(msg, BATADV_ATTR_BLA_BACKBONE, ETH_ALEN,
2166 claim->backbone_gw->orig) ||
2167 nla_put_u16(msg, BATADV_ATTR_BLA_CRC,
2168 backbone_crc)) {
2169 genlmsg_cancel(msg, hdr);
2170 goto out;
2171 }
2172
2173 genlmsg_end(msg, hdr);
2174 ret = 0;
2175
2176 out:
2177 return ret;
2178 }
2179
2180 /**
2181 * batadv_bla_claim_dump_bucket() - dump one bucket of the claim table
2182 * to a netlink socket
2183 * @msg: buffer for the message
2184 * @portid: netlink port
2185 * @cb: Control block containing additional options
2186 * @primary_if: primary interface
2187 * @hash: hash to dump
2188 * @bucket: bucket index to dump
2189 * @idx_skip: How many entries to skip
2190 *
2191 * Return: always 0.
2192 */
2193 static int
2194 batadv_bla_claim_dump_bucket(struct sk_buff *msg, u32 portid,
2195 struct netlink_callback *cb,
2196 struct batadv_hard_iface *primary_if,
2197 struct batadv_hashtable *hash, unsigned int bucket,
2198 int *idx_skip)
2199 {
2200 struct batadv_bla_claim *claim;
2201 int idx = 0;
2202 int ret = 0;
2203
2204 spin_lock_bh(&hash->list_locks[bucket]);
2205 cb->seq = atomic_read(&hash->generation) << 1 | 1;
2206
2207 hlist_for_each_entry(claim, &hash->table[bucket], hash_entry) {
2208 if (idx++ < *idx_skip)
2209 continue;
2210
2211 ret = batadv_bla_claim_dump_entry(msg, portid, cb,
2212 primary_if, claim);
2213 if (ret) {
2214 *idx_skip = idx - 1;
2215 goto unlock;
2216 }
2217 }
2218
2219 *idx_skip = 0;
2220 unlock:
2221 spin_unlock_bh(&hash->list_locks[bucket]);
2222 return ret;
2223 }
2224
2225 /**
2226 * batadv_bla_claim_dump() - dump claim table to a netlink socket
2227 * @msg: buffer for the message
2228 * @cb: callback structure containing arguments
2229 *
2230 * Return: message length.
2231 */
2232 int batadv_bla_claim_dump(struct sk_buff *msg, struct netlink_callback *cb)
2233 {
2234 struct batadv_hard_iface *primary_if = NULL;
2235 int portid = NETLINK_CB(cb->skb).portid;
2236 struct net *net = sock_net(cb->skb->sk);
2237 struct net_device *soft_iface;
2238 struct batadv_hashtable *hash;
2239 struct batadv_priv *bat_priv;
2240 int bucket = cb->args[0];
2241 int idx = cb->args[1];
2242 int ifindex;
2243 int ret = 0;
2244
2245 ifindex = batadv_netlink_get_ifindex(cb->nlh,
2246 BATADV_ATTR_MESH_IFINDEX);
2247 if (!ifindex)
2248 return -EINVAL;
2249
2250 soft_iface = dev_get_by_index(net, ifindex);
2251 if (!soft_iface || !batadv_softif_is_valid(soft_iface)) {
2252 ret = -ENODEV;
2253 goto out;
2254 }
2255
2256 bat_priv = netdev_priv(soft_iface);
2257 hash = bat_priv->bla.claim_hash;
2258
2259 primary_if = batadv_primary_if_get_selected(bat_priv);
2260 if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) {
2261 ret = -ENOENT;
2262 goto out;
2263 }
2264
2265 while (bucket < hash->size) {
2266 if (batadv_bla_claim_dump_bucket(msg, portid, cb, primary_if,
2267 hash, bucket, &idx))
2268 break;
2269 bucket++;
2270 }
2271
2272 cb->args[0] = bucket;
2273 cb->args[1] = idx;
2274
2275 ret = msg->len;
2276
2277 out:
2278 batadv_hardif_put(primary_if);
2279
2280 dev_put(soft_iface);
2281
2282 return ret;
2283 }
2284
2285 /**
2286 * batadv_bla_backbone_dump_entry() - dump one entry of the backbone table to a
2287 * netlink socket
2288 * @msg: buffer for the message
2289 * @portid: netlink port
2290 * @cb: Control block containing additional options
2291 * @primary_if: primary interface
2292 * @backbone_gw: entry to dump
2293 *
2294 * Return: 0 or error code.
2295 */
2296 static int
2297 batadv_bla_backbone_dump_entry(struct sk_buff *msg, u32 portid,
2298 struct netlink_callback *cb,
2299 struct batadv_hard_iface *primary_if,
2300 struct batadv_bla_backbone_gw *backbone_gw)
2301 {
2302 const u8 *primary_addr = primary_if->net_dev->dev_addr;
2303 u16 backbone_crc;
2304 bool is_own;
2305 int msecs;
2306 void *hdr;
2307 int ret = -EINVAL;
2308
2309 hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq,
2310 &batadv_netlink_family, NLM_F_MULTI,
2311 BATADV_CMD_GET_BLA_BACKBONE);
2312 if (!hdr) {
2313 ret = -ENOBUFS;
2314 goto out;
2315 }
2316
2317 genl_dump_check_consistent(cb, hdr);
2318
2319 is_own = batadv_compare_eth(backbone_gw->orig, primary_addr);
2320
2321 spin_lock_bh(&backbone_gw->crc_lock);
2322 backbone_crc = backbone_gw->crc;
2323 spin_unlock_bh(&backbone_gw->crc_lock);
2324
2325 msecs = jiffies_to_msecs(jiffies - backbone_gw->lasttime);
2326
2327 if (is_own)
2328 if (nla_put_flag(msg, BATADV_ATTR_BLA_OWN)) {
2329 genlmsg_cancel(msg, hdr);
2330 goto out;
2331 }
2332
2333 if (nla_put(msg, BATADV_ATTR_BLA_BACKBONE, ETH_ALEN,
2334 backbone_gw->orig) ||
2335 nla_put_u16(msg, BATADV_ATTR_BLA_VID, backbone_gw->vid) ||
2336 nla_put_u16(msg, BATADV_ATTR_BLA_CRC,
2337 backbone_crc) ||
2338 nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS, msecs)) {
2339 genlmsg_cancel(msg, hdr);
2340 goto out;
2341 }
2342
2343 genlmsg_end(msg, hdr);
2344 ret = 0;
2345
2346 out:
2347 return ret;
2348 }
2349
2350 /**
2351 * batadv_bla_backbone_dump_bucket() - dump one bucket of the backbone table to
2352 * a netlink socket
2353 * @msg: buffer for the message
2354 * @portid: netlink port
2355 * @cb: Control block containing additional options
2356 * @primary_if: primary interface
2357 * @hash: hash to dump
2358 * @bucket: bucket index to dump
2359 * @idx_skip: How many entries to skip
2360 *
2361 * Return: always 0.
2362 */
2363 static int
2364 batadv_bla_backbone_dump_bucket(struct sk_buff *msg, u32 portid,
2365 struct netlink_callback *cb,
2366 struct batadv_hard_iface *primary_if,
2367 struct batadv_hashtable *hash,
2368 unsigned int bucket, int *idx_skip)
2369 {
2370 struct batadv_bla_backbone_gw *backbone_gw;
2371 int idx = 0;
2372 int ret = 0;
2373
2374 spin_lock_bh(&hash->list_locks[bucket]);
2375 cb->seq = atomic_read(&hash->generation) << 1 | 1;
2376
2377 hlist_for_each_entry(backbone_gw, &hash->table[bucket], hash_entry) {
2378 if (idx++ < *idx_skip)
2379 continue;
2380
2381 ret = batadv_bla_backbone_dump_entry(msg, portid, cb,
2382 primary_if, backbone_gw);
2383 if (ret) {
2384 *idx_skip = idx - 1;
2385 goto unlock;
2386 }
2387 }
2388
2389 *idx_skip = 0;
2390 unlock:
2391 spin_unlock_bh(&hash->list_locks[bucket]);
2392 return ret;
2393 }
2394
2395 /**
2396 * batadv_bla_backbone_dump() - dump backbone table to a netlink socket
2397 * @msg: buffer for the message
2398 * @cb: callback structure containing arguments
2399 *
2400 * Return: message length.
2401 */
2402 int batadv_bla_backbone_dump(struct sk_buff *msg, struct netlink_callback *cb)
2403 {
2404 struct batadv_hard_iface *primary_if = NULL;
2405 int portid = NETLINK_CB(cb->skb).portid;
2406 struct net *net = sock_net(cb->skb->sk);
2407 struct net_device *soft_iface;
2408 struct batadv_hashtable *hash;
2409 struct batadv_priv *bat_priv;
2410 int bucket = cb->args[0];
2411 int idx = cb->args[1];
2412 int ifindex;
2413 int ret = 0;
2414
2415 ifindex = batadv_netlink_get_ifindex(cb->nlh,
2416 BATADV_ATTR_MESH_IFINDEX);
2417 if (!ifindex)
2418 return -EINVAL;
2419
2420 soft_iface = dev_get_by_index(net, ifindex);
2421 if (!soft_iface || !batadv_softif_is_valid(soft_iface)) {
2422 ret = -ENODEV;
2423 goto out;
2424 }
2425
2426 bat_priv = netdev_priv(soft_iface);
2427 hash = bat_priv->bla.backbone_hash;
2428
2429 primary_if = batadv_primary_if_get_selected(bat_priv);
2430 if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) {
2431 ret = -ENOENT;
2432 goto out;
2433 }
2434
2435 while (bucket < hash->size) {
2436 if (batadv_bla_backbone_dump_bucket(msg, portid, cb, primary_if,
2437 hash, bucket, &idx))
2438 break;
2439 bucket++;
2440 }
2441
2442 cb->args[0] = bucket;
2443 cb->args[1] = idx;
2444
2445 ret = msg->len;
2446
2447 out:
2448 batadv_hardif_put(primary_if);
2449
2450 dev_put(soft_iface);
2451
2452 return ret;
2453 }
2454
2455 #ifdef CONFIG_BATMAN_ADV_DAT
2456 /**
2457 * batadv_bla_check_claim() - check if address is claimed
2458 *
2459 * @bat_priv: the bat priv with all the soft interface information
2460 * @addr: mac address of which the claim status is checked
2461 * @vid: the VLAN ID
2462 *
2463 * addr is checked if this address is claimed by the local device itself.
2464 *
2465 * Return: true if bla is disabled or the mac is claimed by the device,
2466 * false if the device addr is already claimed by another gateway
2467 */
2468 bool batadv_bla_check_claim(struct batadv_priv *bat_priv,
2469 u8 *addr, unsigned short vid)
2470 {
2471 struct batadv_bla_claim search_claim;
2472 struct batadv_bla_claim *claim = NULL;
2473 struct batadv_hard_iface *primary_if = NULL;
2474 bool ret = true;
2475
2476 if (!atomic_read(&bat_priv->bridge_loop_avoidance))
2477 return ret;
2478
2479 primary_if = batadv_primary_if_get_selected(bat_priv);
2480 if (!primary_if)
2481 return ret;
2482
2483 /* First look if the mac address is claimed */
2484 ether_addr_copy(search_claim.addr, addr);
2485 search_claim.vid = vid;
2486
2487 claim = batadv_claim_hash_find(bat_priv, &search_claim);
2488
2489 /* If there is a claim and we are not owner of the claim,
2490 * return false.
2491 */
2492 if (claim) {
2493 if (!batadv_compare_eth(claim->backbone_gw->orig,
2494 primary_if->net_dev->dev_addr))
2495 ret = false;
2496 batadv_claim_put(claim);
2497 }
2498
2499 batadv_hardif_put(primary_if);
2500 return ret;
2501 }
2502 #endif
2503
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