Linux 4.8-rc8
[linux/fpc-iii.git] / net / batman-adv / routing.c
blob3d199478c4054300ea0b83085116d839a64047f4
1 /* Copyright (C) 2007-2016 B.A.T.M.A.N. contributors:
3 * Marek Lindner, Simon Wunderlich
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of version 2 of the GNU General Public
7 * License as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 #include "routing.h"
19 #include "main.h"
21 #include <linux/atomic.h>
22 #include <linux/byteorder/generic.h>
23 #include <linux/compiler.h>
24 #include <linux/errno.h>
25 #include <linux/etherdevice.h>
26 #include <linux/if_ether.h>
27 #include <linux/jiffies.h>
28 #include <linux/kref.h>
29 #include <linux/netdevice.h>
30 #include <linux/printk.h>
31 #include <linux/rculist.h>
32 #include <linux/rcupdate.h>
33 #include <linux/skbuff.h>
34 #include <linux/spinlock.h>
35 #include <linux/stddef.h>
37 #include "bitarray.h"
38 #include "bridge_loop_avoidance.h"
39 #include "distributed-arp-table.h"
40 #include "fragmentation.h"
41 #include "hard-interface.h"
42 #include "icmp_socket.h"
43 #include "log.h"
44 #include "network-coding.h"
45 #include "originator.h"
46 #include "packet.h"
47 #include "send.h"
48 #include "soft-interface.h"
49 #include "tp_meter.h"
50 #include "translation-table.h"
51 #include "tvlv.h"
53 static int batadv_route_unicast_packet(struct sk_buff *skb,
54 struct batadv_hard_iface *recv_if);
56 /**
57 * _batadv_update_route - set the router for this originator
58 * @bat_priv: the bat priv with all the soft interface information
59 * @orig_node: orig node which is to be configured
60 * @recv_if: the receive interface for which this route is set
61 * @neigh_node: neighbor which should be the next router
63 * This function does not perform any error checks
65 static void _batadv_update_route(struct batadv_priv *bat_priv,
66 struct batadv_orig_node *orig_node,
67 struct batadv_hard_iface *recv_if,
68 struct batadv_neigh_node *neigh_node)
70 struct batadv_orig_ifinfo *orig_ifinfo;
71 struct batadv_neigh_node *curr_router;
73 orig_ifinfo = batadv_orig_ifinfo_get(orig_node, recv_if);
74 if (!orig_ifinfo)
75 return;
77 rcu_read_lock();
78 curr_router = rcu_dereference(orig_ifinfo->router);
79 if (curr_router && !kref_get_unless_zero(&curr_router->refcount))
80 curr_router = NULL;
81 rcu_read_unlock();
83 /* route deleted */
84 if ((curr_router) && (!neigh_node)) {
85 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
86 "Deleting route towards: %pM\n", orig_node->orig);
87 batadv_tt_global_del_orig(bat_priv, orig_node, -1,
88 "Deleted route towards originator");
90 /* route added */
91 } else if ((!curr_router) && (neigh_node)) {
92 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
93 "Adding route towards: %pM (via %pM)\n",
94 orig_node->orig, neigh_node->addr);
95 /* route changed */
96 } else if (neigh_node && curr_router) {
97 batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
98 "Changing route towards: %pM (now via %pM - was via %pM)\n",
99 orig_node->orig, neigh_node->addr,
100 curr_router->addr);
103 if (curr_router)
104 batadv_neigh_node_put(curr_router);
106 spin_lock_bh(&orig_node->neigh_list_lock);
107 /* curr_router used earlier may not be the current orig_ifinfo->router
108 * anymore because it was dereferenced outside of the neigh_list_lock
109 * protected region. After the new best neighbor has replace the current
110 * best neighbor the reference counter needs to decrease. Consequently,
111 * the code needs to ensure the curr_router variable contains a pointer
112 * to the replaced best neighbor.
114 curr_router = rcu_dereference_protected(orig_ifinfo->router, true);
116 /* increase refcount of new best neighbor */
117 if (neigh_node)
118 kref_get(&neigh_node->refcount);
120 rcu_assign_pointer(orig_ifinfo->router, neigh_node);
121 spin_unlock_bh(&orig_node->neigh_list_lock);
122 batadv_orig_ifinfo_put(orig_ifinfo);
124 /* decrease refcount of previous best neighbor */
125 if (curr_router)
126 batadv_neigh_node_put(curr_router);
130 * batadv_update_route - set the router for this originator
131 * @bat_priv: the bat priv with all the soft interface information
132 * @orig_node: orig node which is to be configured
133 * @recv_if: the receive interface for which this route is set
134 * @neigh_node: neighbor which should be the next router
136 void batadv_update_route(struct batadv_priv *bat_priv,
137 struct batadv_orig_node *orig_node,
138 struct batadv_hard_iface *recv_if,
139 struct batadv_neigh_node *neigh_node)
141 struct batadv_neigh_node *router = NULL;
143 if (!orig_node)
144 goto out;
146 router = batadv_orig_router_get(orig_node, recv_if);
148 if (router != neigh_node)
149 _batadv_update_route(bat_priv, orig_node, recv_if, neigh_node);
151 out:
152 if (router)
153 batadv_neigh_node_put(router);
157 * batadv_window_protected - checks whether the host restarted and is in the
158 * protection time.
159 * @bat_priv: the bat priv with all the soft interface information
160 * @seq_num_diff: difference between the current/received sequence number and
161 * the last sequence number
162 * @seq_old_max_diff: maximum age of sequence number not considered as restart
163 * @last_reset: jiffies timestamp of the last reset, will be updated when reset
164 * is detected
165 * @protection_started: is set to true if the protection window was started,
166 * doesn't change otherwise.
168 * Return:
169 * false if the packet is to be accepted.
170 * true if the packet is to be ignored.
172 bool batadv_window_protected(struct batadv_priv *bat_priv, s32 seq_num_diff,
173 s32 seq_old_max_diff, unsigned long *last_reset,
174 bool *protection_started)
176 if (seq_num_diff <= -seq_old_max_diff ||
177 seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) {
178 if (!batadv_has_timed_out(*last_reset,
179 BATADV_RESET_PROTECTION_MS))
180 return true;
182 *last_reset = jiffies;
183 if (protection_started)
184 *protection_started = true;
185 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
186 "old packet received, start protection\n");
189 return false;
192 bool batadv_check_management_packet(struct sk_buff *skb,
193 struct batadv_hard_iface *hard_iface,
194 int header_len)
196 struct ethhdr *ethhdr;
198 /* drop packet if it has not necessary minimum size */
199 if (unlikely(!pskb_may_pull(skb, header_len)))
200 return false;
202 ethhdr = eth_hdr(skb);
204 /* packet with broadcast indication but unicast recipient */
205 if (!is_broadcast_ether_addr(ethhdr->h_dest))
206 return false;
208 /* packet with broadcast sender address */
209 if (is_broadcast_ether_addr(ethhdr->h_source))
210 return false;
212 /* create a copy of the skb, if needed, to modify it. */
213 if (skb_cow(skb, 0) < 0)
214 return false;
216 /* keep skb linear */
217 if (skb_linearize(skb) < 0)
218 return false;
220 return true;
224 * batadv_recv_my_icmp_packet - receive an icmp packet locally
225 * @bat_priv: the bat priv with all the soft interface information
226 * @skb: icmp packet to process
228 * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
229 * otherwise.
231 static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
232 struct sk_buff *skb)
234 struct batadv_hard_iface *primary_if = NULL;
235 struct batadv_orig_node *orig_node = NULL;
236 struct batadv_icmp_header *icmph;
237 int res, ret = NET_RX_DROP;
239 icmph = (struct batadv_icmp_header *)skb->data;
241 switch (icmph->msg_type) {
242 case BATADV_ECHO_REPLY:
243 case BATADV_DESTINATION_UNREACHABLE:
244 case BATADV_TTL_EXCEEDED:
245 /* receive the packet */
246 if (skb_linearize(skb) < 0)
247 break;
249 batadv_socket_receive_packet(icmph, skb->len);
250 break;
251 case BATADV_ECHO_REQUEST:
252 /* answer echo request (ping) */
253 primary_if = batadv_primary_if_get_selected(bat_priv);
254 if (!primary_if)
255 goto out;
257 /* get routing information */
258 orig_node = batadv_orig_hash_find(bat_priv, icmph->orig);
259 if (!orig_node)
260 goto out;
262 /* create a copy of the skb, if needed, to modify it. */
263 if (skb_cow(skb, ETH_HLEN) < 0)
264 goto out;
266 icmph = (struct batadv_icmp_header *)skb->data;
268 ether_addr_copy(icmph->dst, icmph->orig);
269 ether_addr_copy(icmph->orig, primary_if->net_dev->dev_addr);
270 icmph->msg_type = BATADV_ECHO_REPLY;
271 icmph->ttl = BATADV_TTL;
273 res = batadv_send_skb_to_orig(skb, orig_node, NULL);
274 if (res == -1)
275 goto out;
277 ret = NET_RX_SUCCESS;
279 break;
280 case BATADV_TP:
281 if (!pskb_may_pull(skb, sizeof(struct batadv_icmp_tp_packet)))
282 goto out;
284 batadv_tp_meter_recv(bat_priv, skb);
285 ret = NET_RX_SUCCESS;
286 goto out;
287 default:
288 /* drop unknown type */
289 goto out;
291 out:
292 if (primary_if)
293 batadv_hardif_put(primary_if);
294 if (orig_node)
295 batadv_orig_node_put(orig_node);
296 return ret;
299 static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
300 struct sk_buff *skb)
302 struct batadv_hard_iface *primary_if = NULL;
303 struct batadv_orig_node *orig_node = NULL;
304 struct batadv_icmp_packet *icmp_packet;
305 int res, ret = NET_RX_DROP;
307 icmp_packet = (struct batadv_icmp_packet *)skb->data;
309 /* send TTL exceeded if packet is an echo request (traceroute) */
310 if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
311 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
312 icmp_packet->orig, icmp_packet->dst);
313 goto out;
316 primary_if = batadv_primary_if_get_selected(bat_priv);
317 if (!primary_if)
318 goto out;
320 /* get routing information */
321 orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
322 if (!orig_node)
323 goto out;
325 /* create a copy of the skb, if needed, to modify it. */
326 if (skb_cow(skb, ETH_HLEN) < 0)
327 goto out;
329 icmp_packet = (struct batadv_icmp_packet *)skb->data;
331 ether_addr_copy(icmp_packet->dst, icmp_packet->orig);
332 ether_addr_copy(icmp_packet->orig, primary_if->net_dev->dev_addr);
333 icmp_packet->msg_type = BATADV_TTL_EXCEEDED;
334 icmp_packet->ttl = BATADV_TTL;
336 res = batadv_send_skb_to_orig(skb, orig_node, NULL);
337 if (res != -1)
338 ret = NET_RX_SUCCESS;
340 out:
341 if (primary_if)
342 batadv_hardif_put(primary_if);
343 if (orig_node)
344 batadv_orig_node_put(orig_node);
345 return ret;
348 int batadv_recv_icmp_packet(struct sk_buff *skb,
349 struct batadv_hard_iface *recv_if)
351 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
352 struct batadv_icmp_header *icmph;
353 struct batadv_icmp_packet_rr *icmp_packet_rr;
354 struct ethhdr *ethhdr;
355 struct batadv_orig_node *orig_node = NULL;
356 int hdr_size = sizeof(struct batadv_icmp_header);
357 int res, ret = NET_RX_DROP;
359 /* drop packet if it has not necessary minimum size */
360 if (unlikely(!pskb_may_pull(skb, hdr_size)))
361 goto out;
363 ethhdr = eth_hdr(skb);
365 /* packet with unicast indication but broadcast recipient */
366 if (is_broadcast_ether_addr(ethhdr->h_dest))
367 goto out;
369 /* packet with broadcast sender address */
370 if (is_broadcast_ether_addr(ethhdr->h_source))
371 goto out;
373 /* not for me */
374 if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
375 goto out;
377 icmph = (struct batadv_icmp_header *)skb->data;
379 /* add record route information if not full */
380 if ((icmph->msg_type == BATADV_ECHO_REPLY ||
381 icmph->msg_type == BATADV_ECHO_REQUEST) &&
382 (skb->len >= sizeof(struct batadv_icmp_packet_rr))) {
383 if (skb_linearize(skb) < 0)
384 goto out;
386 /* create a copy of the skb, if needed, to modify it. */
387 if (skb_cow(skb, ETH_HLEN) < 0)
388 goto out;
390 ethhdr = eth_hdr(skb);
391 icmph = (struct batadv_icmp_header *)skb->data;
392 icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph;
393 if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN)
394 goto out;
396 ether_addr_copy(icmp_packet_rr->rr[icmp_packet_rr->rr_cur],
397 ethhdr->h_dest);
398 icmp_packet_rr->rr_cur++;
401 /* packet for me */
402 if (batadv_is_my_mac(bat_priv, icmph->dst))
403 return batadv_recv_my_icmp_packet(bat_priv, skb);
405 /* TTL exceeded */
406 if (icmph->ttl < 2)
407 return batadv_recv_icmp_ttl_exceeded(bat_priv, skb);
409 /* get routing information */
410 orig_node = batadv_orig_hash_find(bat_priv, icmph->dst);
411 if (!orig_node)
412 goto out;
414 /* create a copy of the skb, if needed, to modify it. */
415 if (skb_cow(skb, ETH_HLEN) < 0)
416 goto out;
418 icmph = (struct batadv_icmp_header *)skb->data;
420 /* decrement ttl */
421 icmph->ttl--;
423 /* route it */
424 res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
425 if (res != -1)
426 ret = NET_RX_SUCCESS;
428 out:
429 if (orig_node)
430 batadv_orig_node_put(orig_node);
431 return ret;
435 * batadv_check_unicast_packet - Check for malformed unicast packets
436 * @bat_priv: the bat priv with all the soft interface information
437 * @skb: packet to check
438 * @hdr_size: size of header to pull
440 * Check for short header and bad addresses in given packet.
442 * Return: negative value when check fails and 0 otherwise. The negative value
443 * depends on the reason: -ENODATA for bad header, -EBADR for broadcast
444 * destination or source, and -EREMOTE for non-local (other host) destination.
446 static int batadv_check_unicast_packet(struct batadv_priv *bat_priv,
447 struct sk_buff *skb, int hdr_size)
449 struct ethhdr *ethhdr;
451 /* drop packet if it has not necessary minimum size */
452 if (unlikely(!pskb_may_pull(skb, hdr_size)))
453 return -ENODATA;
455 ethhdr = eth_hdr(skb);
457 /* packet with unicast indication but broadcast recipient */
458 if (is_broadcast_ether_addr(ethhdr->h_dest))
459 return -EBADR;
461 /* packet with broadcast sender address */
462 if (is_broadcast_ether_addr(ethhdr->h_source))
463 return -EBADR;
465 /* not for me */
466 if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
467 return -EREMOTE;
469 return 0;
473 * batadv_last_bonding_get - Get last_bonding_candidate of orig_node
474 * @orig_node: originator node whose last bonding candidate should be retrieved
476 * Return: last bonding candidate of router or NULL if not found
478 * The object is returned with refcounter increased by 1.
480 static struct batadv_orig_ifinfo *
481 batadv_last_bonding_get(struct batadv_orig_node *orig_node)
483 struct batadv_orig_ifinfo *last_bonding_candidate;
485 spin_lock_bh(&orig_node->neigh_list_lock);
486 last_bonding_candidate = orig_node->last_bonding_candidate;
488 if (last_bonding_candidate)
489 kref_get(&last_bonding_candidate->refcount);
490 spin_unlock_bh(&orig_node->neigh_list_lock);
492 return last_bonding_candidate;
496 * batadv_last_bonding_replace - Replace last_bonding_candidate of orig_node
497 * @orig_node: originator node whose bonding candidates should be replaced
498 * @new_candidate: new bonding candidate or NULL
500 static void
501 batadv_last_bonding_replace(struct batadv_orig_node *orig_node,
502 struct batadv_orig_ifinfo *new_candidate)
504 struct batadv_orig_ifinfo *old_candidate;
506 spin_lock_bh(&orig_node->neigh_list_lock);
507 old_candidate = orig_node->last_bonding_candidate;
509 if (new_candidate)
510 kref_get(&new_candidate->refcount);
511 orig_node->last_bonding_candidate = new_candidate;
512 spin_unlock_bh(&orig_node->neigh_list_lock);
514 if (old_candidate)
515 batadv_orig_ifinfo_put(old_candidate);
519 * batadv_find_router - find a suitable router for this originator
520 * @bat_priv: the bat priv with all the soft interface information
521 * @orig_node: the destination node
522 * @recv_if: pointer to interface this packet was received on
524 * Return: the router which should be used for this orig_node on
525 * this interface, or NULL if not available.
527 struct batadv_neigh_node *
528 batadv_find_router(struct batadv_priv *bat_priv,
529 struct batadv_orig_node *orig_node,
530 struct batadv_hard_iface *recv_if)
532 struct batadv_algo_ops *bao = bat_priv->algo_ops;
533 struct batadv_neigh_node *first_candidate_router = NULL;
534 struct batadv_neigh_node *next_candidate_router = NULL;
535 struct batadv_neigh_node *router, *cand_router = NULL;
536 struct batadv_neigh_node *last_cand_router = NULL;
537 struct batadv_orig_ifinfo *cand, *first_candidate = NULL;
538 struct batadv_orig_ifinfo *next_candidate = NULL;
539 struct batadv_orig_ifinfo *last_candidate;
540 bool last_candidate_found = false;
542 if (!orig_node)
543 return NULL;
545 router = batadv_orig_router_get(orig_node, recv_if);
547 if (!router)
548 return router;
550 /* only consider bonding for recv_if == BATADV_IF_DEFAULT (first hop)
551 * and if activated.
553 if (!(recv_if == BATADV_IF_DEFAULT && atomic_read(&bat_priv->bonding)))
554 return router;
556 /* bonding: loop through the list of possible routers found
557 * for the various outgoing interfaces and find a candidate after
558 * the last chosen bonding candidate (next_candidate). If no such
559 * router is found, use the first candidate found (the previously
560 * chosen bonding candidate might have been the last one in the list).
561 * If this can't be found either, return the previously chosen
562 * router - obviously there are no other candidates.
564 rcu_read_lock();
565 last_candidate = batadv_last_bonding_get(orig_node);
566 if (last_candidate)
567 last_cand_router = rcu_dereference(last_candidate->router);
569 hlist_for_each_entry_rcu(cand, &orig_node->ifinfo_list, list) {
570 /* acquire some structures and references ... */
571 if (!kref_get_unless_zero(&cand->refcount))
572 continue;
574 cand_router = rcu_dereference(cand->router);
575 if (!cand_router)
576 goto next;
578 if (!kref_get_unless_zero(&cand_router->refcount)) {
579 cand_router = NULL;
580 goto next;
583 /* alternative candidate should be good enough to be
584 * considered
586 if (!bao->neigh.is_similar_or_better(cand_router,
587 cand->if_outgoing, router,
588 recv_if))
589 goto next;
591 /* don't use the same router twice */
592 if (last_cand_router == cand_router)
593 goto next;
595 /* mark the first possible candidate */
596 if (!first_candidate) {
597 kref_get(&cand_router->refcount);
598 kref_get(&cand->refcount);
599 first_candidate = cand;
600 first_candidate_router = cand_router;
603 /* check if the loop has already passed the previously selected
604 * candidate ... this function should select the next candidate
605 * AFTER the previously used bonding candidate.
607 if (!last_candidate || last_candidate_found) {
608 next_candidate = cand;
609 next_candidate_router = cand_router;
610 break;
613 if (last_candidate == cand)
614 last_candidate_found = true;
615 next:
616 /* free references */
617 if (cand_router) {
618 batadv_neigh_node_put(cand_router);
619 cand_router = NULL;
621 batadv_orig_ifinfo_put(cand);
623 rcu_read_unlock();
625 /* After finding candidates, handle the three cases:
626 * 1) there is a next candidate, use that
627 * 2) there is no next candidate, use the first of the list
628 * 3) there is no candidate at all, return the default router
630 if (next_candidate) {
631 batadv_neigh_node_put(router);
633 kref_get(&next_candidate_router->refcount);
634 router = next_candidate_router;
635 batadv_last_bonding_replace(orig_node, next_candidate);
636 } else if (first_candidate) {
637 batadv_neigh_node_put(router);
639 kref_get(&first_candidate_router->refcount);
640 router = first_candidate_router;
641 batadv_last_bonding_replace(orig_node, first_candidate);
642 } else {
643 batadv_last_bonding_replace(orig_node, NULL);
646 /* cleanup of candidates */
647 if (first_candidate) {
648 batadv_neigh_node_put(first_candidate_router);
649 batadv_orig_ifinfo_put(first_candidate);
652 if (next_candidate) {
653 batadv_neigh_node_put(next_candidate_router);
654 batadv_orig_ifinfo_put(next_candidate);
657 if (last_candidate)
658 batadv_orig_ifinfo_put(last_candidate);
660 return router;
663 static int batadv_route_unicast_packet(struct sk_buff *skb,
664 struct batadv_hard_iface *recv_if)
666 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
667 struct batadv_orig_node *orig_node = NULL;
668 struct batadv_unicast_packet *unicast_packet;
669 struct ethhdr *ethhdr = eth_hdr(skb);
670 int res, hdr_len, ret = NET_RX_DROP;
671 unsigned int len;
673 unicast_packet = (struct batadv_unicast_packet *)skb->data;
675 /* TTL exceeded */
676 if (unicast_packet->ttl < 2) {
677 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
678 ethhdr->h_source, unicast_packet->dest);
679 goto out;
682 /* get routing information */
683 orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
685 if (!orig_node)
686 goto out;
688 /* create a copy of the skb, if needed, to modify it. */
689 if (skb_cow(skb, ETH_HLEN) < 0)
690 goto out;
692 /* decrement ttl */
693 unicast_packet = (struct batadv_unicast_packet *)skb->data;
694 unicast_packet->ttl--;
696 switch (unicast_packet->packet_type) {
697 case BATADV_UNICAST_4ADDR:
698 hdr_len = sizeof(struct batadv_unicast_4addr_packet);
699 break;
700 case BATADV_UNICAST:
701 hdr_len = sizeof(struct batadv_unicast_packet);
702 break;
703 default:
704 /* other packet types not supported - yet */
705 hdr_len = -1;
706 break;
709 if (hdr_len > 0)
710 batadv_skb_set_priority(skb, hdr_len);
712 len = skb->len;
713 res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
714 if (res == -1)
715 goto out;
717 /* translate transmit result into receive result */
718 if (res == NET_XMIT_SUCCESS) {
719 /* skb was transmitted and consumed */
720 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
721 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
722 len + ETH_HLEN);
725 ret = NET_RX_SUCCESS;
727 out:
728 if (orig_node)
729 batadv_orig_node_put(orig_node);
730 return ret;
734 * batadv_reroute_unicast_packet - update the unicast header for re-routing
735 * @bat_priv: the bat priv with all the soft interface information
736 * @unicast_packet: the unicast header to be updated
737 * @dst_addr: the payload destination
738 * @vid: VLAN identifier
740 * Search the translation table for dst_addr and update the unicast header with
741 * the new corresponding information (originator address where the destination
742 * client currently is and its known TTVN)
744 * Return: true if the packet header has been updated, false otherwise
746 static bool
747 batadv_reroute_unicast_packet(struct batadv_priv *bat_priv,
748 struct batadv_unicast_packet *unicast_packet,
749 u8 *dst_addr, unsigned short vid)
751 struct batadv_orig_node *orig_node = NULL;
752 struct batadv_hard_iface *primary_if = NULL;
753 bool ret = false;
754 u8 *orig_addr, orig_ttvn;
756 if (batadv_is_my_client(bat_priv, dst_addr, vid)) {
757 primary_if = batadv_primary_if_get_selected(bat_priv);
758 if (!primary_if)
759 goto out;
760 orig_addr = primary_if->net_dev->dev_addr;
761 orig_ttvn = (u8)atomic_read(&bat_priv->tt.vn);
762 } else {
763 orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr,
764 vid);
765 if (!orig_node)
766 goto out;
768 if (batadv_compare_eth(orig_node->orig, unicast_packet->dest))
769 goto out;
771 orig_addr = orig_node->orig;
772 orig_ttvn = (u8)atomic_read(&orig_node->last_ttvn);
775 /* update the packet header */
776 ether_addr_copy(unicast_packet->dest, orig_addr);
777 unicast_packet->ttvn = orig_ttvn;
779 ret = true;
780 out:
781 if (primary_if)
782 batadv_hardif_put(primary_if);
783 if (orig_node)
784 batadv_orig_node_put(orig_node);
786 return ret;
789 static bool batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
790 struct sk_buff *skb, int hdr_len)
792 struct batadv_unicast_packet *unicast_packet;
793 struct batadv_hard_iface *primary_if;
794 struct batadv_orig_node *orig_node;
795 u8 curr_ttvn, old_ttvn;
796 struct ethhdr *ethhdr;
797 unsigned short vid;
798 int is_old_ttvn;
800 /* check if there is enough data before accessing it */
801 if (!pskb_may_pull(skb, hdr_len + ETH_HLEN))
802 return false;
804 /* create a copy of the skb (in case of for re-routing) to modify it. */
805 if (skb_cow(skb, sizeof(*unicast_packet)) < 0)
806 return false;
808 unicast_packet = (struct batadv_unicast_packet *)skb->data;
809 vid = batadv_get_vid(skb, hdr_len);
810 ethhdr = (struct ethhdr *)(skb->data + hdr_len);
812 /* check if the destination client was served by this node and it is now
813 * roaming. In this case, it means that the node has got a ROAM_ADV
814 * message and that it knows the new destination in the mesh to re-route
815 * the packet to
817 if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) {
818 if (batadv_reroute_unicast_packet(bat_priv, unicast_packet,
819 ethhdr->h_dest, vid))
820 batadv_dbg_ratelimited(BATADV_DBG_TT,
821 bat_priv,
822 "Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n",
823 unicast_packet->dest,
824 ethhdr->h_dest);
825 /* at this point the mesh destination should have been
826 * substituted with the originator address found in the global
827 * table. If not, let the packet go untouched anyway because
828 * there is nothing the node can do
830 return true;
833 /* retrieve the TTVN known by this node for the packet destination. This
834 * value is used later to check if the node which sent (or re-routed
835 * last time) the packet had an updated information or not
837 curr_ttvn = (u8)atomic_read(&bat_priv->tt.vn);
838 if (!batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
839 orig_node = batadv_orig_hash_find(bat_priv,
840 unicast_packet->dest);
841 /* if it is not possible to find the orig_node representing the
842 * destination, the packet can immediately be dropped as it will
843 * not be possible to deliver it
845 if (!orig_node)
846 return false;
848 curr_ttvn = (u8)atomic_read(&orig_node->last_ttvn);
849 batadv_orig_node_put(orig_node);
852 /* check if the TTVN contained in the packet is fresher than what the
853 * node knows
855 is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
856 if (!is_old_ttvn)
857 return true;
859 old_ttvn = unicast_packet->ttvn;
860 /* the packet was forged based on outdated network information. Its
861 * destination can possibly be updated and forwarded towards the new
862 * target host
864 if (batadv_reroute_unicast_packet(bat_priv, unicast_packet,
865 ethhdr->h_dest, vid)) {
866 batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv,
867 "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n",
868 unicast_packet->dest, ethhdr->h_dest,
869 old_ttvn, curr_ttvn);
870 return true;
873 /* the packet has not been re-routed: either the destination is
874 * currently served by this node or there is no destination at all and
875 * it is possible to drop the packet
877 if (!batadv_is_my_client(bat_priv, ethhdr->h_dest, vid))
878 return false;
880 /* update the header in order to let the packet be delivered to this
881 * node's soft interface
883 primary_if = batadv_primary_if_get_selected(bat_priv);
884 if (!primary_if)
885 return false;
887 ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr);
889 batadv_hardif_put(primary_if);
891 unicast_packet->ttvn = curr_ttvn;
893 return true;
897 * batadv_recv_unhandled_unicast_packet - receive and process packets which
898 * are in the unicast number space but not yet known to the implementation
899 * @skb: unicast tvlv packet to process
900 * @recv_if: pointer to interface this packet was received on
902 * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
903 * otherwise.
905 int batadv_recv_unhandled_unicast_packet(struct sk_buff *skb,
906 struct batadv_hard_iface *recv_if)
908 struct batadv_unicast_packet *unicast_packet;
909 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
910 int check, hdr_size = sizeof(*unicast_packet);
912 check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
913 if (check < 0)
914 return NET_RX_DROP;
916 /* we don't know about this type, drop it. */
917 unicast_packet = (struct batadv_unicast_packet *)skb->data;
918 if (batadv_is_my_mac(bat_priv, unicast_packet->dest))
919 return NET_RX_DROP;
921 return batadv_route_unicast_packet(skb, recv_if);
924 int batadv_recv_unicast_packet(struct sk_buff *skb,
925 struct batadv_hard_iface *recv_if)
927 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
928 struct batadv_unicast_packet *unicast_packet;
929 struct batadv_unicast_4addr_packet *unicast_4addr_packet;
930 u8 *orig_addr;
931 struct batadv_orig_node *orig_node = NULL;
932 int check, hdr_size = sizeof(*unicast_packet);
933 enum batadv_subtype subtype;
934 bool is4addr;
936 unicast_packet = (struct batadv_unicast_packet *)skb->data;
937 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
939 is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR;
940 /* the caller function should have already pulled 2 bytes */
941 if (is4addr)
942 hdr_size = sizeof(*unicast_4addr_packet);
944 /* function returns -EREMOTE for promiscuous packets */
945 check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
947 /* Even though the packet is not for us, we might save it to use for
948 * decoding a later received coded packet
950 if (check == -EREMOTE)
951 batadv_nc_skb_store_sniffed_unicast(bat_priv, skb);
953 if (check < 0)
954 return NET_RX_DROP;
955 if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size))
956 return NET_RX_DROP;
958 /* packet for me */
959 if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
960 if (is4addr) {
961 subtype = unicast_4addr_packet->subtype;
962 batadv_dat_inc_counter(bat_priv, subtype);
964 /* Only payload data should be considered for speedy
965 * join. For example, DAT also uses unicast 4addr
966 * types, but those packets should not be considered
967 * for speedy join, since the clients do not actually
968 * reside at the sending originator.
970 if (subtype == BATADV_P_DATA) {
971 orig_addr = unicast_4addr_packet->src;
972 orig_node = batadv_orig_hash_find(bat_priv,
973 orig_addr);
977 if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb,
978 hdr_size))
979 goto rx_success;
980 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb,
981 hdr_size))
982 goto rx_success;
984 batadv_interface_rx(recv_if->soft_iface, skb, hdr_size,
985 orig_node);
987 rx_success:
988 if (orig_node)
989 batadv_orig_node_put(orig_node);
991 return NET_RX_SUCCESS;
994 return batadv_route_unicast_packet(skb, recv_if);
998 * batadv_recv_unicast_tvlv - receive and process unicast tvlv packets
999 * @skb: unicast tvlv packet to process
1000 * @recv_if: pointer to interface this packet was received on
1002 * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
1003 * otherwise.
1005 int batadv_recv_unicast_tvlv(struct sk_buff *skb,
1006 struct batadv_hard_iface *recv_if)
1008 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1009 struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
1010 unsigned char *tvlv_buff;
1011 u16 tvlv_buff_len;
1012 int hdr_size = sizeof(*unicast_tvlv_packet);
1013 int ret = NET_RX_DROP;
1015 if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0)
1016 return NET_RX_DROP;
1018 /* the header is likely to be modified while forwarding */
1019 if (skb_cow(skb, hdr_size) < 0)
1020 return NET_RX_DROP;
1022 /* packet needs to be linearized to access the tvlv content */
1023 if (skb_linearize(skb) < 0)
1024 return NET_RX_DROP;
1026 unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)skb->data;
1028 tvlv_buff = (unsigned char *)(skb->data + hdr_size);
1029 tvlv_buff_len = ntohs(unicast_tvlv_packet->tvlv_len);
1031 if (tvlv_buff_len > skb->len - hdr_size)
1032 return NET_RX_DROP;
1034 ret = batadv_tvlv_containers_process(bat_priv, false, NULL,
1035 unicast_tvlv_packet->src,
1036 unicast_tvlv_packet->dst,
1037 tvlv_buff, tvlv_buff_len);
1039 if (ret != NET_RX_SUCCESS)
1040 ret = batadv_route_unicast_packet(skb, recv_if);
1041 else
1042 consume_skb(skb);
1044 return ret;
1048 * batadv_recv_frag_packet - process received fragment
1049 * @skb: the received fragment
1050 * @recv_if: interface that the skb is received on
1052 * This function does one of the three following things: 1) Forward fragment, if
1053 * the assembled packet will exceed our MTU; 2) Buffer fragment, if we till
1054 * lack further fragments; 3) Merge fragments, if we have all needed parts.
1056 * Return: NET_RX_DROP if the skb is not consumed, NET_RX_SUCCESS otherwise.
1058 int batadv_recv_frag_packet(struct sk_buff *skb,
1059 struct batadv_hard_iface *recv_if)
1061 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1062 struct batadv_orig_node *orig_node_src = NULL;
1063 struct batadv_frag_packet *frag_packet;
1064 int ret = NET_RX_DROP;
1066 if (batadv_check_unicast_packet(bat_priv, skb,
1067 sizeof(*frag_packet)) < 0)
1068 goto out;
1070 frag_packet = (struct batadv_frag_packet *)skb->data;
1071 orig_node_src = batadv_orig_hash_find(bat_priv, frag_packet->orig);
1072 if (!orig_node_src)
1073 goto out;
1075 skb->priority = frag_packet->priority + 256;
1077 /* Route the fragment if it is not for us and too big to be merged. */
1078 if (!batadv_is_my_mac(bat_priv, frag_packet->dest) &&
1079 batadv_frag_skb_fwd(skb, recv_if, orig_node_src)) {
1080 ret = NET_RX_SUCCESS;
1081 goto out;
1084 batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX);
1085 batadv_add_counter(bat_priv, BATADV_CNT_FRAG_RX_BYTES, skb->len);
1087 /* Add fragment to buffer and merge if possible. */
1088 if (!batadv_frag_skb_buffer(&skb, orig_node_src))
1089 goto out;
1091 /* Deliver merged packet to the appropriate handler, if it was
1092 * merged
1094 if (skb)
1095 batadv_batman_skb_recv(skb, recv_if->net_dev,
1096 &recv_if->batman_adv_ptype, NULL);
1098 ret = NET_RX_SUCCESS;
1100 out:
1101 if (orig_node_src)
1102 batadv_orig_node_put(orig_node_src);
1104 return ret;
1107 int batadv_recv_bcast_packet(struct sk_buff *skb,
1108 struct batadv_hard_iface *recv_if)
1110 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
1111 struct batadv_orig_node *orig_node = NULL;
1112 struct batadv_bcast_packet *bcast_packet;
1113 struct ethhdr *ethhdr;
1114 int hdr_size = sizeof(*bcast_packet);
1115 int ret = NET_RX_DROP;
1116 s32 seq_diff;
1117 u32 seqno;
1119 /* drop packet if it has not necessary minimum size */
1120 if (unlikely(!pskb_may_pull(skb, hdr_size)))
1121 goto out;
1123 ethhdr = eth_hdr(skb);
1125 /* packet with broadcast indication but unicast recipient */
1126 if (!is_broadcast_ether_addr(ethhdr->h_dest))
1127 goto out;
1129 /* packet with broadcast sender address */
1130 if (is_broadcast_ether_addr(ethhdr->h_source))
1131 goto out;
1133 /* ignore broadcasts sent by myself */
1134 if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
1135 goto out;
1137 bcast_packet = (struct batadv_bcast_packet *)skb->data;
1139 /* ignore broadcasts originated by myself */
1140 if (batadv_is_my_mac(bat_priv, bcast_packet->orig))
1141 goto out;
1143 if (bcast_packet->ttl < 2)
1144 goto out;
1146 orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
1148 if (!orig_node)
1149 goto out;
1151 spin_lock_bh(&orig_node->bcast_seqno_lock);
1153 seqno = ntohl(bcast_packet->seqno);
1154 /* check whether the packet is a duplicate */
1155 if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
1156 seqno))
1157 goto spin_unlock;
1159 seq_diff = seqno - orig_node->last_bcast_seqno;
1161 /* check whether the packet is old and the host just restarted. */
1162 if (batadv_window_protected(bat_priv, seq_diff,
1163 BATADV_BCAST_MAX_AGE,
1164 &orig_node->bcast_seqno_reset, NULL))
1165 goto spin_unlock;
1167 /* mark broadcast in flood history, update window position
1168 * if required.
1170 if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
1171 orig_node->last_bcast_seqno = seqno;
1173 spin_unlock_bh(&orig_node->bcast_seqno_lock);
1175 /* check whether this has been sent by another originator before */
1176 if (batadv_bla_check_bcast_duplist(bat_priv, skb))
1177 goto out;
1179 batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet));
1181 /* rebroadcast packet */
1182 batadv_add_bcast_packet_to_list(bat_priv, skb, 1);
1184 /* don't hand the broadcast up if it is from an originator
1185 * from the same backbone.
1187 if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
1188 goto out;
1190 if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size))
1191 goto rx_success;
1192 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size))
1193 goto rx_success;
1195 /* broadcast for me */
1196 batadv_interface_rx(recv_if->soft_iface, skb, hdr_size, orig_node);
1198 rx_success:
1199 ret = NET_RX_SUCCESS;
1200 goto out;
1202 spin_unlock:
1203 spin_unlock_bh(&orig_node->bcast_seqno_lock);
1204 out:
1205 if (orig_node)
1206 batadv_orig_node_put(orig_node);
1207 return ret;