1 /*
2 * Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
3 *
4 * Marek Lindner, Simon Wunderlich
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of version 2 of the GNU General Public
8 * License as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18 * 02110-1301, USA
19 *
20 */
21
22 #include "main.h"
23 #include "routing.h"
24 #include "send.h"
25 #include "soft-interface.h"
26 #include "hard-interface.h"
27 #include "icmp_socket.h"
28 #include "translation-table.h"
29 #include "originator.h"
30 #include "vis.h"
31 #include "unicast.h"
32
slide_own_bcast_window(struct hard_iface * hard_iface)33 void slide_own_bcast_window(struct hard_iface *hard_iface)
34 {
35 struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
36 struct hashtable_t *hash = bat_priv->orig_hash;
37 struct hlist_node *node;
38 struct hlist_head *head;
39 struct orig_node *orig_node;
40 unsigned long *word;
41 uint32_t i;
42 size_t word_index;
43
44 for (i = 0; i < hash->size; i++) {
45 head = &hash->table[i];
46
47 rcu_read_lock();
48 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
49 spin_lock_bh(&orig_node->ogm_cnt_lock);
50 word_index = hard_iface->if_num * NUM_WORDS;
51 word = &(orig_node->bcast_own[word_index]);
52
53 bit_get_packet(bat_priv, word, 1, 0);
54 orig_node->bcast_own_sum[hard_iface->if_num] =
55 bit_packet_count(word);
56 spin_unlock_bh(&orig_node->ogm_cnt_lock);
57 }
58 rcu_read_unlock();
59 }
60 }
61
_update_route(struct bat_priv * bat_priv,struct orig_node * orig_node,struct neigh_node * neigh_node)62 static void _update_route(struct bat_priv *bat_priv,
63 struct orig_node *orig_node,
64 struct neigh_node *neigh_node)
65 {
66 struct neigh_node *curr_router;
67
68 curr_router = orig_node_get_router(orig_node);
69
70 /* route deleted */
71 if ((curr_router) && (!neigh_node)) {
72 bat_dbg(DBG_ROUTES, bat_priv, "Deleting route towards: %pM\n",
73 orig_node->orig);
74 tt_global_del_orig(bat_priv, orig_node,
75 "Deleted route towards originator");
76
77 /* route added */
78 } else if ((!curr_router) && (neigh_node)) {
79
80 bat_dbg(DBG_ROUTES, bat_priv,
81 "Adding route towards: %pM (via %pM)\n",
82 orig_node->orig, neigh_node->addr);
83 /* route changed */
84 } else if (neigh_node && curr_router) {
85 bat_dbg(DBG_ROUTES, bat_priv,
86 "Changing route towards: %pM (now via %pM - was via %pM)\n",
87 orig_node->orig, neigh_node->addr,
88 curr_router->addr);
89 }
90
91 if (curr_router)
92 neigh_node_free_ref(curr_router);
93
94 /* increase refcount of new best neighbor */
95 if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
96 neigh_node = NULL;
97
98 spin_lock_bh(&orig_node->neigh_list_lock);
99 rcu_assign_pointer(orig_node->router, neigh_node);
100 spin_unlock_bh(&orig_node->neigh_list_lock);
101
102 /* decrease refcount of previous best neighbor */
103 if (curr_router)
104 neigh_node_free_ref(curr_router);
105 }
106
update_route(struct bat_priv * bat_priv,struct orig_node * orig_node,struct neigh_node * neigh_node)107 void update_route(struct bat_priv *bat_priv, struct orig_node *orig_node,
108 struct neigh_node *neigh_node)
109 {
110 struct neigh_node *router = NULL;
111
112 if (!orig_node)
113 goto out;
114
115 router = orig_node_get_router(orig_node);
116
117 if (router != neigh_node)
118 _update_route(bat_priv, orig_node, neigh_node);
119
120 out:
121 if (router)
122 neigh_node_free_ref(router);
123 }
124
125 /* caller must hold the neigh_list_lock */
bonding_candidate_del(struct orig_node * orig_node,struct neigh_node * neigh_node)126 void bonding_candidate_del(struct orig_node *orig_node,
127 struct neigh_node *neigh_node)
128 {
129 /* this neighbor is not part of our candidate list */
130 if (list_empty(&neigh_node->bonding_list))
131 goto out;
132
133 list_del_rcu(&neigh_node->bonding_list);
134 INIT_LIST_HEAD(&neigh_node->bonding_list);
135 neigh_node_free_ref(neigh_node);
136 atomic_dec(&orig_node->bond_candidates);
137
138 out:
139 return;
140 }
141
bonding_candidate_add(struct orig_node * orig_node,struct neigh_node * neigh_node)142 void bonding_candidate_add(struct orig_node *orig_node,
143 struct neigh_node *neigh_node)
144 {
145 struct hlist_node *node;
146 struct neigh_node *tmp_neigh_node, *router = NULL;
147 uint8_t interference_candidate = 0;
148
149 spin_lock_bh(&orig_node->neigh_list_lock);
150
151 /* only consider if it has the same primary address ... */
152 if (!compare_eth(orig_node->orig,
153 neigh_node->orig_node->primary_addr))
154 goto candidate_del;
155
156 router = orig_node_get_router(orig_node);
157 if (!router)
158 goto candidate_del;
159
160 /* ... and is good enough to be considered */
161 if (neigh_node->tq_avg < router->tq_avg - BONDING_TQ_THRESHOLD)
162 goto candidate_del;
163
164 /**
165 * check if we have another candidate with the same mac address or
166 * interface. If we do, we won't select this candidate because of
167 * possible interference.
168 */
169 hlist_for_each_entry_rcu(tmp_neigh_node, node,
170 &orig_node->neigh_list, list) {
171
172 if (tmp_neigh_node == neigh_node)
173 continue;
174
175 /* we only care if the other candidate is even
176 * considered as candidate. */
177 if (list_empty(&tmp_neigh_node->bonding_list))
178 continue;
179
180 if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) ||
181 (compare_eth(neigh_node->addr, tmp_neigh_node->addr))) {
182 interference_candidate = 1;
183 break;
184 }
185 }
186
187 /* don't care further if it is an interference candidate */
188 if (interference_candidate)
189 goto candidate_del;
190
191 /* this neighbor already is part of our candidate list */
192 if (!list_empty(&neigh_node->bonding_list))
193 goto out;
194
195 if (!atomic_inc_not_zero(&neigh_node->refcount))
196 goto out;
197
198 list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list);
199 atomic_inc(&orig_node->bond_candidates);
200 goto out;
201
202 candidate_del:
203 bonding_candidate_del(orig_node, neigh_node);
204
205 out:
206 spin_unlock_bh(&orig_node->neigh_list_lock);
207
208 if (router)
209 neigh_node_free_ref(router);
210 }
211
212 /* copy primary address for bonding */
bonding_save_primary(const struct orig_node * orig_node,struct orig_node * orig_neigh_node,const struct batman_ogm_packet * batman_ogm_packet)213 void bonding_save_primary(const struct orig_node *orig_node,
214 struct orig_node *orig_neigh_node,
215 const struct batman_ogm_packet *batman_ogm_packet)
216 {
217 if (!(batman_ogm_packet->flags & PRIMARIES_FIRST_HOP))
218 return;
219
220 memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
221 }
222
223 /* checks whether the host restarted and is in the protection time.
224 * returns:
225 * 0 if the packet is to be accepted
226 * 1 if the packet is to be ignored.
227 */
window_protected(struct bat_priv * bat_priv,int32_t seq_num_diff,unsigned long * last_reset)228 int window_protected(struct bat_priv *bat_priv, int32_t seq_num_diff,
229 unsigned long *last_reset)
230 {
231 if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE) ||
232 (seq_num_diff >= EXPECTED_SEQNO_RANGE)) {
233 if (has_timed_out(*last_reset, RESET_PROTECTION_MS)) {
234
235 *last_reset = jiffies;
236 bat_dbg(DBG_BATMAN, bat_priv,
237 "old packet received, start protection\n");
238
239 return 0;
240 } else {
241 return 1;
242 }
243 }
244 return 0;
245 }
246
recv_bat_ogm_packet(struct sk_buff * skb,struct hard_iface * hard_iface)247 int recv_bat_ogm_packet(struct sk_buff *skb, struct hard_iface *hard_iface)
248 {
249 struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
250 struct ethhdr *ethhdr;
251
252 /* drop packet if it has not necessary minimum size */
253 if (unlikely(!pskb_may_pull(skb, BATMAN_OGM_LEN)))
254 return NET_RX_DROP;
255
256 ethhdr = (struct ethhdr *)skb_mac_header(skb);
257
258 /* packet with broadcast indication but unicast recipient */
259 if (!is_broadcast_ether_addr(ethhdr->h_dest))
260 return NET_RX_DROP;
261
262 /* packet with broadcast sender address */
263 if (is_broadcast_ether_addr(ethhdr->h_source))
264 return NET_RX_DROP;
265
266 /* create a copy of the skb, if needed, to modify it. */
267 if (skb_cow(skb, 0) < 0)
268 return NET_RX_DROP;
269
270 /* keep skb linear */
271 if (skb_linearize(skb) < 0)
272 return NET_RX_DROP;
273
274 bat_priv->bat_algo_ops->bat_ogm_receive(hard_iface, skb);
275
276 kfree_skb(skb);
277 return NET_RX_SUCCESS;
278 }
279
recv_my_icmp_packet(struct bat_priv * bat_priv,struct sk_buff * skb,size_t icmp_len)280 static int recv_my_icmp_packet(struct bat_priv *bat_priv,
281 struct sk_buff *skb, size_t icmp_len)
282 {
283 struct hard_iface *primary_if = NULL;
284 struct orig_node *orig_node = NULL;
285 struct neigh_node *router = NULL;
286 struct icmp_packet_rr *icmp_packet;
287 int ret = NET_RX_DROP;
288
289 icmp_packet = (struct icmp_packet_rr *)skb->data;
290
291 /* add data to device queue */
292 if (icmp_packet->msg_type != ECHO_REQUEST) {
293 bat_socket_receive_packet(icmp_packet, icmp_len);
294 goto out;
295 }
296
297 primary_if = primary_if_get_selected(bat_priv);
298 if (!primary_if)
299 goto out;
300
301 /* answer echo request (ping) */
302 /* get routing information */
303 orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
304 if (!orig_node)
305 goto out;
306
307 router = orig_node_get_router(orig_node);
308 if (!router)
309 goto out;
310
311 /* create a copy of the skb, if needed, to modify it. */
312 if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
313 goto out;
314
315 icmp_packet = (struct icmp_packet_rr *)skb->data;
316
317 memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
318 memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
319 icmp_packet->msg_type = ECHO_REPLY;
320 icmp_packet->header.ttl = TTL;
321
322 send_skb_packet(skb, router->if_incoming, router->addr);
323 ret = NET_RX_SUCCESS;
324
325 out:
326 if (primary_if)
327 hardif_free_ref(primary_if);
328 if (router)
329 neigh_node_free_ref(router);
330 if (orig_node)
331 orig_node_free_ref(orig_node);
332 return ret;
333 }
334
recv_icmp_ttl_exceeded(struct bat_priv * bat_priv,struct sk_buff * skb)335 static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
336 struct sk_buff *skb)
337 {
338 struct hard_iface *primary_if = NULL;
339 struct orig_node *orig_node = NULL;
340 struct neigh_node *router = NULL;
341 struct icmp_packet *icmp_packet;
342 int ret = NET_RX_DROP;
343
344 icmp_packet = (struct icmp_packet *)skb->data;
345
346 /* send TTL exceeded if packet is an echo request (traceroute) */
347 if (icmp_packet->msg_type != ECHO_REQUEST) {
348 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
349 icmp_packet->orig, icmp_packet->dst);
350 goto out;
351 }
352
353 primary_if = primary_if_get_selected(bat_priv);
354 if (!primary_if)
355 goto out;
356
357 /* get routing information */
358 orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
359 if (!orig_node)
360 goto out;
361
362 router = orig_node_get_router(orig_node);
363 if (!router)
364 goto out;
365
366 /* create a copy of the skb, if needed, to modify it. */
367 if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
368 goto out;
369
370 icmp_packet = (struct icmp_packet *)skb->data;
371
372 memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
373 memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
374 icmp_packet->msg_type = TTL_EXCEEDED;
375 icmp_packet->header.ttl = TTL;
376
377 send_skb_packet(skb, router->if_incoming, router->addr);
378 ret = NET_RX_SUCCESS;
379
380 out:
381 if (primary_if)
382 hardif_free_ref(primary_if);
383 if (router)
384 neigh_node_free_ref(router);
385 if (orig_node)
386 orig_node_free_ref(orig_node);
387 return ret;
388 }
389
390
recv_icmp_packet(struct sk_buff * skb,struct hard_iface * recv_if)391 int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
392 {
393 struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
394 struct icmp_packet_rr *icmp_packet;
395 struct ethhdr *ethhdr;
396 struct orig_node *orig_node = NULL;
397 struct neigh_node *router = NULL;
398 int hdr_size = sizeof(struct icmp_packet);
399 int ret = NET_RX_DROP;
400
401 /**
402 * we truncate all incoming icmp packets if they don't match our size
403 */
404 if (skb->len >= sizeof(struct icmp_packet_rr))
405 hdr_size = sizeof(struct icmp_packet_rr);
406
407 /* drop packet if it has not necessary minimum size */
408 if (unlikely(!pskb_may_pull(skb, hdr_size)))
409 goto out;
410
411 ethhdr = (struct ethhdr *)skb_mac_header(skb);
412
413 /* packet with unicast indication but broadcast recipient */
414 if (is_broadcast_ether_addr(ethhdr->h_dest))
415 goto out;
416
417 /* packet with broadcast sender address */
418 if (is_broadcast_ether_addr(ethhdr->h_source))
419 goto out;
420
421 /* not for me */
422 if (!is_my_mac(ethhdr->h_dest))
423 goto out;
424
425 icmp_packet = (struct icmp_packet_rr *)skb->data;
426
427 /* add record route information if not full */
428 if ((hdr_size == sizeof(struct icmp_packet_rr)) &&
429 (icmp_packet->rr_cur < BAT_RR_LEN)) {
430 memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
431 ethhdr->h_dest, ETH_ALEN);
432 icmp_packet->rr_cur++;
433 }
434
435 /* packet for me */
436 if (is_my_mac(icmp_packet->dst))
437 return recv_my_icmp_packet(bat_priv, skb, hdr_size);
438
439 /* TTL exceeded */
440 if (icmp_packet->header.ttl < 2)
441 return recv_icmp_ttl_exceeded(bat_priv, skb);
442
443 /* get routing information */
444 orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
445 if (!orig_node)
446 goto out;
447
448 router = orig_node_get_router(orig_node);
449 if (!router)
450 goto out;
451
452 /* create a copy of the skb, if needed, to modify it. */
453 if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
454 goto out;
455
456 icmp_packet = (struct icmp_packet_rr *)skb->data;
457
458 /* decrement ttl */
459 icmp_packet->header.ttl--;
460
461 /* route it */
462 send_skb_packet(skb, router->if_incoming, router->addr);
463 ret = NET_RX_SUCCESS;
464
465 out:
466 if (router)
467 neigh_node_free_ref(router);
468 if (orig_node)
469 orig_node_free_ref(orig_node);
470 return ret;
471 }
472
473 /* In the bonding case, send the packets in a round
474 * robin fashion over the remaining interfaces.
475 *
476 * This method rotates the bonding list and increases the
477 * returned router's refcount. */
find_bond_router(struct orig_node * primary_orig,const struct hard_iface * recv_if)478 static struct neigh_node *find_bond_router(struct orig_node *primary_orig,
479 const struct hard_iface *recv_if)
480 {
481 struct neigh_node *tmp_neigh_node;
482 struct neigh_node *router = NULL, *first_candidate = NULL;
483
484 rcu_read_lock();
485 list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
486 bonding_list) {
487 if (!first_candidate)
488 first_candidate = tmp_neigh_node;
489
490 /* recv_if == NULL on the first node. */
491 if (tmp_neigh_node->if_incoming == recv_if)
492 continue;
493
494 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
495 continue;
496
497 router = tmp_neigh_node;
498 break;
499 }
500
501 /* use the first candidate if nothing was found. */
502 if (!router && first_candidate &&
503 atomic_inc_not_zero(&first_candidate->refcount))
504 router = first_candidate;
505
506 if (!router)
507 goto out;
508
509 /* selected should point to the next element
510 * after the current router */
511 spin_lock_bh(&primary_orig->neigh_list_lock);
512 /* this is a list_move(), which unfortunately
513 * does not exist as rcu version */
514 list_del_rcu(&primary_orig->bond_list);
515 list_add_rcu(&primary_orig->bond_list,
516 &router->bonding_list);
517 spin_unlock_bh(&primary_orig->neigh_list_lock);
518
519 out:
520 rcu_read_unlock();
521 return router;
522 }
523
524 /* Interface Alternating: Use the best of the
525 * remaining candidates which are not using
526 * this interface.
527 *
528 * Increases the returned router's refcount */
find_ifalter_router(struct orig_node * primary_orig,const struct hard_iface * recv_if)529 static struct neigh_node *find_ifalter_router(struct orig_node *primary_orig,
530 const struct hard_iface *recv_if)
531 {
532 struct neigh_node *tmp_neigh_node;
533 struct neigh_node *router = NULL, *first_candidate = NULL;
534
535 rcu_read_lock();
536 list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
537 bonding_list) {
538 if (!first_candidate)
539 first_candidate = tmp_neigh_node;
540
541 /* recv_if == NULL on the first node. */
542 if (tmp_neigh_node->if_incoming == recv_if)
543 continue;
544
545 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
546 continue;
547
548 /* if we don't have a router yet
549 * or this one is better, choose it. */
550 if ((!router) ||
551 (tmp_neigh_node->tq_avg > router->tq_avg)) {
552 /* decrement refcount of
553 * previously selected router */
554 if (router)
555 neigh_node_free_ref(router);
556
557 router = tmp_neigh_node;
558 atomic_inc_not_zero(&router->refcount);
559 }
560
561 neigh_node_free_ref(tmp_neigh_node);
562 }
563
564 /* use the first candidate if nothing was found. */
565 if (!router && first_candidate &&
566 atomic_inc_not_zero(&first_candidate->refcount))
567 router = first_candidate;
568
569 rcu_read_unlock();
570 return router;
571 }
572
recv_tt_query(struct sk_buff * skb,struct hard_iface * recv_if)573 int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if)
574 {
575 struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
576 struct tt_query_packet *tt_query;
577 uint16_t tt_len;
578 struct ethhdr *ethhdr;
579
580 /* drop packet if it has not necessary minimum size */
581 if (unlikely(!pskb_may_pull(skb, sizeof(struct tt_query_packet))))
582 goto out;
583
584 /* I could need to modify it */
585 if (skb_cow(skb, sizeof(struct tt_query_packet)) < 0)
586 goto out;
587
588 ethhdr = (struct ethhdr *)skb_mac_header(skb);
589
590 /* packet with unicast indication but broadcast recipient */
591 if (is_broadcast_ether_addr(ethhdr->h_dest))
592 goto out;
593
594 /* packet with broadcast sender address */
595 if (is_broadcast_ether_addr(ethhdr->h_source))
596 goto out;
597
598 tt_query = (struct tt_query_packet *)skb->data;
599
600 tt_query->tt_data = ntohs(tt_query->tt_data);
601
602 switch (tt_query->flags & TT_QUERY_TYPE_MASK) {
603 case TT_REQUEST:
604 /* If we cannot provide an answer the tt_request is
605 * forwarded */
606 if (!send_tt_response(bat_priv, tt_query)) {
607 bat_dbg(DBG_TT, bat_priv,
608 "Routing TT_REQUEST to %pM [%c]\n",
609 tt_query->dst,
610 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
611 tt_query->tt_data = htons(tt_query->tt_data);
612 return route_unicast_packet(skb, recv_if);
613 }
614 break;
615 case TT_RESPONSE:
616 if (is_my_mac(tt_query->dst)) {
617 /* packet needs to be linearized to access the TT
618 * changes */
619 if (skb_linearize(skb) < 0)
620 goto out;
621 /* skb_linearize() possibly changed skb->data */
622 tt_query = (struct tt_query_packet *)skb->data;
623
624 tt_len = tt_query->tt_data * sizeof(struct tt_change);
625
626 /* Ensure we have all the claimed data */
627 if (unlikely(skb_headlen(skb) <
628 sizeof(struct tt_query_packet) + tt_len))
629 goto out;
630
631 handle_tt_response(bat_priv, tt_query);
632 } else {
633 bat_dbg(DBG_TT, bat_priv,
634 "Routing TT_RESPONSE to %pM [%c]\n",
635 tt_query->dst,
636 (tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
637 tt_query->tt_data = htons(tt_query->tt_data);
638 return route_unicast_packet(skb, recv_if);
639 }
640 break;
641 }
642
643 out:
644 /* returning NET_RX_DROP will make the caller function kfree the skb */
645 return NET_RX_DROP;
646 }
647
recv_roam_adv(struct sk_buff * skb,struct hard_iface * recv_if)648 int recv_roam_adv(struct sk_buff *skb, struct hard_iface *recv_if)
649 {
650 struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
651 struct roam_adv_packet *roam_adv_packet;
652 struct orig_node *orig_node;
653 struct ethhdr *ethhdr;
654
655 /* drop packet if it has not necessary minimum size */
656 if (unlikely(!pskb_may_pull(skb, sizeof(struct roam_adv_packet))))
657 goto out;
658
659 ethhdr = (struct ethhdr *)skb_mac_header(skb);
660
661 /* packet with unicast indication but broadcast recipient */
662 if (is_broadcast_ether_addr(ethhdr->h_dest))
663 goto out;
664
665 /* packet with broadcast sender address */
666 if (is_broadcast_ether_addr(ethhdr->h_source))
667 goto out;
668
669 roam_adv_packet = (struct roam_adv_packet *)skb->data;
670
671 if (!is_my_mac(roam_adv_packet->dst))
672 return route_unicast_packet(skb, recv_if);
673
674 orig_node = orig_hash_find(bat_priv, roam_adv_packet->src);
675 if (!orig_node)
676 goto out;
677
678 bat_dbg(DBG_TT, bat_priv,
679 "Received ROAMING_ADV from %pM (client %pM)\n",
680 roam_adv_packet->src, roam_adv_packet->client);
681
682 tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
683 atomic_read(&orig_node->last_ttvn) + 1, true, false);
684
685 /* Roaming phase starts: I have new information but the ttvn has not
686 * been incremented yet. This flag will make me check all the incoming
687 * packets for the correct destination. */
688 bat_priv->tt_poss_change = true;
689
690 orig_node_free_ref(orig_node);
691 out:
692 /* returning NET_RX_DROP will make the caller function kfree the skb */
693 return NET_RX_DROP;
694 }
695
696 /* find a suitable router for this originator, and use
697 * bonding if possible. increases the found neighbors
698 * refcount.*/
find_router(struct bat_priv * bat_priv,struct orig_node * orig_node,const struct hard_iface * recv_if)699 struct neigh_node *find_router(struct bat_priv *bat_priv,
700 struct orig_node *orig_node,
701 const struct hard_iface *recv_if)
702 {
703 struct orig_node *primary_orig_node;
704 struct orig_node *router_orig;
705 struct neigh_node *router;
706 static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
707 int bonding_enabled;
708
709 if (!orig_node)
710 return NULL;
711
712 router = orig_node_get_router(orig_node);
713 if (!router)
714 goto err;
715
716 /* without bonding, the first node should
717 * always choose the default router. */
718 bonding_enabled = atomic_read(&bat_priv->bonding);
719
720 rcu_read_lock();
721 /* select default router to output */
722 router_orig = router->orig_node;
723 if (!router_orig)
724 goto err_unlock;
725
726 if ((!recv_if) && (!bonding_enabled))
727 goto return_router;
728
729 /* if we have something in the primary_addr, we can search
730 * for a potential bonding candidate. */
731 if (compare_eth(router_orig->primary_addr, zero_mac))
732 goto return_router;
733
734 /* find the orig_node which has the primary interface. might
735 * even be the same as our router_orig in many cases */
736
737 if (compare_eth(router_orig->primary_addr, router_orig->orig)) {
738 primary_orig_node = router_orig;
739 } else {
740 primary_orig_node = orig_hash_find(bat_priv,
741 router_orig->primary_addr);
742 if (!primary_orig_node)
743 goto return_router;
744
745 orig_node_free_ref(primary_orig_node);
746 }
747
748 /* with less than 2 candidates, we can't do any
749 * bonding and prefer the original router. */
750 if (atomic_read(&primary_orig_node->bond_candidates) < 2)
751 goto return_router;
752
753 /* all nodes between should choose a candidate which
754 * is is not on the interface where the packet came
755 * in. */
756
757 neigh_node_free_ref(router);
758
759 if (bonding_enabled)
760 router = find_bond_router(primary_orig_node, recv_if);
761 else
762 router = find_ifalter_router(primary_orig_node, recv_if);
763
764 return_router:
765 if (router && router->if_incoming->if_status != IF_ACTIVE)
766 goto err_unlock;
767
768 rcu_read_unlock();
769 return router;
770 err_unlock:
771 rcu_read_unlock();
772 err:
773 if (router)
774 neigh_node_free_ref(router);
775 return NULL;
776 }
777
check_unicast_packet(struct sk_buff * skb,int hdr_size)778 static int check_unicast_packet(struct sk_buff *skb, int hdr_size)
779 {
780 struct ethhdr *ethhdr;
781
782 /* drop packet if it has not necessary minimum size */
783 if (unlikely(!pskb_may_pull(skb, hdr_size)))
784 return -1;
785
786 ethhdr = (struct ethhdr *)skb_mac_header(skb);
787
788 /* packet with unicast indication but broadcast recipient */
789 if (is_broadcast_ether_addr(ethhdr->h_dest))
790 return -1;
791
792 /* packet with broadcast sender address */
793 if (is_broadcast_ether_addr(ethhdr->h_source))
794 return -1;
795
796 /* not for me */
797 if (!is_my_mac(ethhdr->h_dest))
798 return -1;
799
800 return 0;
801 }
802
route_unicast_packet(struct sk_buff * skb,struct hard_iface * recv_if)803 int route_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
804 {
805 struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
806 struct orig_node *orig_node = NULL;
807 struct neigh_node *neigh_node = NULL;
808 struct unicast_packet *unicast_packet;
809 struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
810 int ret = NET_RX_DROP;
811 struct sk_buff *new_skb;
812
813 unicast_packet = (struct unicast_packet *)skb->data;
814
815 /* TTL exceeded */
816 if (unicast_packet->header.ttl < 2) {
817 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
818 ethhdr->h_source, unicast_packet->dest);
819 goto out;
820 }
821
822 /* get routing information */
823 orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
824
825 if (!orig_node)
826 goto out;
827
828 /* find_router() increases neigh_nodes refcount if found. */
829 neigh_node = find_router(bat_priv, orig_node, recv_if);
830
831 if (!neigh_node)
832 goto out;
833
834 /* create a copy of the skb, if needed, to modify it. */
835 if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
836 goto out;
837
838 unicast_packet = (struct unicast_packet *)skb->data;
839
840 if (unicast_packet->header.packet_type == BAT_UNICAST &&
841 atomic_read(&bat_priv->fragmentation) &&
842 skb->len > neigh_node->if_incoming->net_dev->mtu) {
843 ret = frag_send_skb(skb, bat_priv,
844 neigh_node->if_incoming, neigh_node->addr);
845 goto out;
846 }
847
848 if (unicast_packet->header.packet_type == BAT_UNICAST_FRAG &&
849 frag_can_reassemble(skb, neigh_node->if_incoming->net_dev->mtu)) {
850
851 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
852
853 if (ret == NET_RX_DROP)
854 goto out;
855
856 /* packet was buffered for late merge */
857 if (!new_skb) {
858 ret = NET_RX_SUCCESS;
859 goto out;
860 }
861
862 skb = new_skb;
863 unicast_packet = (struct unicast_packet *)skb->data;
864 }
865
866 /* decrement ttl */
867 unicast_packet->header.ttl--;
868
869 /* route it */
870 send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
871 ret = NET_RX_SUCCESS;
872
873 out:
874 if (neigh_node)
875 neigh_node_free_ref(neigh_node);
876 if (orig_node)
877 orig_node_free_ref(orig_node);
878 return ret;
879 }
880
check_unicast_ttvn(struct bat_priv * bat_priv,struct sk_buff * skb)881 static int check_unicast_ttvn(struct bat_priv *bat_priv,
882 struct sk_buff *skb) {
883 uint8_t curr_ttvn;
884 struct orig_node *orig_node;
885 struct ethhdr *ethhdr;
886 struct hard_iface *primary_if;
887 struct unicast_packet *unicast_packet;
888 bool tt_poss_change;
889
890 /* I could need to modify it */
891 if (skb_cow(skb, sizeof(struct unicast_packet)) < 0)
892 return 0;
893
894 unicast_packet = (struct unicast_packet *)skb->data;
895
896 if (is_my_mac(unicast_packet->dest)) {
897 tt_poss_change = bat_priv->tt_poss_change;
898 curr_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
899 } else {
900 orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
901
902 if (!orig_node)
903 return 0;
904
905 curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
906 tt_poss_change = orig_node->tt_poss_change;
907 orig_node_free_ref(orig_node);
908 }
909
910 /* Check whether I have to reroute the packet */
911 if (seq_before(unicast_packet->ttvn, curr_ttvn) || tt_poss_change) {
912 /* Linearize the skb before accessing it */
913 if (skb_linearize(skb) < 0)
914 return 0;
915
916 ethhdr = (struct ethhdr *)(skb->data +
917 sizeof(struct unicast_packet));
918 orig_node = transtable_search(bat_priv, NULL, ethhdr->h_dest);
919
920 if (!orig_node) {
921 if (!is_my_client(bat_priv, ethhdr->h_dest))
922 return 0;
923 primary_if = primary_if_get_selected(bat_priv);
924 if (!primary_if)
925 return 0;
926 memcpy(unicast_packet->dest,
927 primary_if->net_dev->dev_addr, ETH_ALEN);
928 hardif_free_ref(primary_if);
929 } else {
930 memcpy(unicast_packet->dest, orig_node->orig,
931 ETH_ALEN);
932 curr_ttvn = (uint8_t)
933 atomic_read(&orig_node->last_ttvn);
934 orig_node_free_ref(orig_node);
935 }
936
937 bat_dbg(DBG_ROUTES, bat_priv,
938 "TTVN mismatch (old_ttvn %u new_ttvn %u)! Rerouting unicast packet (for %pM) to %pM\n",
939 unicast_packet->ttvn, curr_ttvn, ethhdr->h_dest,
940 unicast_packet->dest);
941
942 unicast_packet->ttvn = curr_ttvn;
943 }
944 return 1;
945 }
946
recv_unicast_packet(struct sk_buff * skb,struct hard_iface * recv_if)947 int recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
948 {
949 struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
950 struct unicast_packet *unicast_packet;
951 int hdr_size = sizeof(*unicast_packet);
952
953 if (check_unicast_packet(skb, hdr_size) < 0)
954 return NET_RX_DROP;
955
956 if (!check_unicast_ttvn(bat_priv, skb))
957 return NET_RX_DROP;
958
959 unicast_packet = (struct unicast_packet *)skb->data;
960
961 /* packet for me */
962 if (is_my_mac(unicast_packet->dest)) {
963 interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
964 return NET_RX_SUCCESS;
965 }
966
967 return route_unicast_packet(skb, recv_if);
968 }
969
recv_ucast_frag_packet(struct sk_buff * skb,struct hard_iface * recv_if)970 int recv_ucast_frag_packet(struct sk_buff *skb, struct hard_iface *recv_if)
971 {
972 struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
973 struct unicast_frag_packet *unicast_packet;
974 int hdr_size = sizeof(*unicast_packet);
975 struct sk_buff *new_skb = NULL;
976 int ret;
977
978 if (check_unicast_packet(skb, hdr_size) < 0)
979 return NET_RX_DROP;
980
981 if (!check_unicast_ttvn(bat_priv, skb))
982 return NET_RX_DROP;
983
984 unicast_packet = (struct unicast_frag_packet *)skb->data;
985
986 /* packet for me */
987 if (is_my_mac(unicast_packet->dest)) {
988
989 ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
990
991 if (ret == NET_RX_DROP)
992 return NET_RX_DROP;
993
994 /* packet was buffered for late merge */
995 if (!new_skb)
996 return NET_RX_SUCCESS;
997
998 interface_rx(recv_if->soft_iface, new_skb, recv_if,
999 sizeof(struct unicast_packet));
1000 return NET_RX_SUCCESS;
1001 }
1002
1003 return route_unicast_packet(skb, recv_if);
1004 }
1005
1006
recv_bcast_packet(struct sk_buff * skb,struct hard_iface * recv_if)1007 int recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1008 {
1009 struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1010 struct orig_node *orig_node = NULL;
1011 struct bcast_packet *bcast_packet;
1012 struct ethhdr *ethhdr;
1013 int hdr_size = sizeof(*bcast_packet);
1014 int ret = NET_RX_DROP;
1015 int32_t seq_diff;
1016
1017 /* drop packet if it has not necessary minimum size */
1018 if (unlikely(!pskb_may_pull(skb, hdr_size)))
1019 goto out;
1020
1021 ethhdr = (struct ethhdr *)skb_mac_header(skb);
1022
1023 /* packet with broadcast indication but unicast recipient */
1024 if (!is_broadcast_ether_addr(ethhdr->h_dest))
1025 goto out;
1026
1027 /* packet with broadcast sender address */
1028 if (is_broadcast_ether_addr(ethhdr->h_source))
1029 goto out;
1030
1031 /* ignore broadcasts sent by myself */
1032 if (is_my_mac(ethhdr->h_source))
1033 goto out;
1034
1035 bcast_packet = (struct bcast_packet *)skb->data;
1036
1037 /* ignore broadcasts originated by myself */
1038 if (is_my_mac(bcast_packet->orig))
1039 goto out;
1040
1041 if (bcast_packet->header.ttl < 2)
1042 goto out;
1043
1044 orig_node = orig_hash_find(bat_priv, bcast_packet->orig);
1045
1046 if (!orig_node)
1047 goto out;
1048
1049 spin_lock_bh(&orig_node->bcast_seqno_lock);
1050
1051 /* check whether the packet is a duplicate */
1052 if (get_bit_status(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1053 ntohl(bcast_packet->seqno)))
1054 goto spin_unlock;
1055
1056 seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
1057
1058 /* check whether the packet is old and the host just restarted. */
1059 if (window_protected(bat_priv, seq_diff,
1060 &orig_node->bcast_seqno_reset))
1061 goto spin_unlock;
1062
1063 /* mark broadcast in flood history, update window position
1064 * if required. */
1065 if (bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1066 orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
1067
1068 spin_unlock_bh(&orig_node->bcast_seqno_lock);
1069
1070 /* rebroadcast packet */
1071 add_bcast_packet_to_list(bat_priv, skb, 1);
1072
1073 /* broadcast for me */
1074 interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
1075 ret = NET_RX_SUCCESS;
1076 goto out;
1077
1078 spin_unlock:
1079 spin_unlock_bh(&orig_node->bcast_seqno_lock);
1080 out:
1081 if (orig_node)
1082 orig_node_free_ref(orig_node);
1083 return ret;
1084 }
1085
recv_vis_packet(struct sk_buff * skb,struct hard_iface * recv_if)1086 int recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if)
1087 {
1088 struct vis_packet *vis_packet;
1089 struct ethhdr *ethhdr;
1090 struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1091 int hdr_size = sizeof(*vis_packet);
1092
1093 /* keep skb linear */
1094 if (skb_linearize(skb) < 0)
1095 return NET_RX_DROP;
1096
1097 if (unlikely(!pskb_may_pull(skb, hdr_size)))
1098 return NET_RX_DROP;
1099
1100 vis_packet = (struct vis_packet *)skb->data;
1101 ethhdr = (struct ethhdr *)skb_mac_header(skb);
1102
1103 /* not for me */
1104 if (!is_my_mac(ethhdr->h_dest))
1105 return NET_RX_DROP;
1106
1107 /* ignore own packets */
1108 if (is_my_mac(vis_packet->vis_orig))
1109 return NET_RX_DROP;
1110
1111 if (is_my_mac(vis_packet->sender_orig))
1112 return NET_RX_DROP;
1113
1114 switch (vis_packet->vis_type) {
1115 case VIS_TYPE_SERVER_SYNC:
1116 receive_server_sync_packet(bat_priv, vis_packet,
1117 skb_headlen(skb));
1118 break;
1119
1120 case VIS_TYPE_CLIENT_UPDATE:
1121 receive_client_update_packet(bat_priv, vis_packet,
1122 skb_headlen(skb));
1123 break;
1124
1125 default: /* ignore unknown packet */
1126 break;
1127 }
1128
1129 /* We take a copy of the data in the packet, so we should
1130 always free the skbuf. */
1131 return NET_RX_DROP;
1132 }
1133