1 /* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
2 *
3 * Marek Lindner, Simon Wunderlich
4 *
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.
8 *
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.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA
18 */
19
20 #include "main.h"
21 #include "distributed-arp-table.h"
22 #include "send.h"
23 #include "routing.h"
24 #include "translation-table.h"
25 #include "soft-interface.h"
26 #include "hard-interface.h"
27 #include "gateway_common.h"
28 #include "gateway_client.h"
29 #include "originator.h"
30 #include "network-coding.h"
31 #include "fragmentation.h"
32
33 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
34
35 /* send out an already prepared packet to the given address via the
36 * specified batman interface
37 */
38 int batadv_send_skb_packet(struct sk_buff *skb,
39 struct batadv_hard_iface *hard_iface,
40 const uint8_t *dst_addr)
41 {
42 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
43 struct ethhdr *ethhdr;
44
45 if (hard_iface->if_status != BATADV_IF_ACTIVE)
46 goto send_skb_err;
47
48 if (unlikely(!hard_iface->net_dev))
49 goto send_skb_err;
50
51 if (!(hard_iface->net_dev->flags & IFF_UP)) {
52 pr_warn("Interface %s is not up - can't send packet via that interface!\n",
53 hard_iface->net_dev->name);
54 goto send_skb_err;
55 }
56
57 /* push to the ethernet header. */
58 if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
59 goto send_skb_err;
60
61 skb_reset_mac_header(skb);
62
63 ethhdr = eth_hdr(skb);
64 memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
65 memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
66 ethhdr->h_proto = htons(ETH_P_BATMAN);
67
68 skb_set_network_header(skb, ETH_HLEN);
69 skb->protocol = htons(ETH_P_BATMAN);
70
71 skb->dev = hard_iface->net_dev;
72
73 /* Save a clone of the skb to use when decoding coded packets */
74 batadv_nc_skb_store_for_decoding(bat_priv, skb);
75
76 /* dev_queue_xmit() returns a negative result on error. However on
77 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
78 * (which is > 0). This will not be treated as an error.
79 */
80 return dev_queue_xmit(skb);
81 send_skb_err:
82 kfree_skb(skb);
83 return NET_XMIT_DROP;
84 }
85
86 /**
87 * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
88 * @skb: Packet to be transmitted.
89 * @orig_node: Final destination of the packet.
90 * @recv_if: Interface used when receiving the packet (can be NULL).
91 *
92 * Looks up the best next-hop towards the passed originator and passes the
93 * skb on for preparation of MAC header. If the packet originated from this
94 * host, NULL can be passed as recv_if and no interface alternating is
95 * attempted.
96 *
97 * Returns NET_XMIT_SUCCESS on success, NET_XMIT_DROP on failure, or
98 * NET_XMIT_POLICED if the skb is buffered for later transmit.
99 */
100 int batadv_send_skb_to_orig(struct sk_buff *skb,
101 struct batadv_orig_node *orig_node,
102 struct batadv_hard_iface *recv_if)
103 {
104 struct batadv_priv *bat_priv = orig_node->bat_priv;
105 struct batadv_neigh_node *neigh_node;
106 int ret = NET_XMIT_DROP;
107
108 /* batadv_find_router() increases neigh_nodes refcount if found. */
109 neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
110 if (!neigh_node)
111 goto out;
112
113 /* Check if the skb is too large to send in one piece and fragment
114 * it if needed.
115 */
116 if (atomic_read(&bat_priv->fragmentation) &&
117 skb->len > neigh_node->if_incoming->net_dev->mtu) {
118 /* Fragment and send packet. */
119 if (batadv_frag_send_packet(skb, orig_node, neigh_node))
120 ret = NET_XMIT_SUCCESS;
121
122 goto out;
123 }
124
125 /* try to network code the packet, if it is received on an interface
126 * (i.e. being forwarded). If the packet originates from this node or if
127 * network coding fails, then send the packet as usual.
128 */
129 if (recv_if && batadv_nc_skb_forward(skb, neigh_node)) {
130 ret = NET_XMIT_POLICED;
131 } else {
132 batadv_send_skb_packet(skb, neigh_node->if_incoming,
133 neigh_node->addr);
134 ret = NET_XMIT_SUCCESS;
135 }
136
137 out:
138 if (neigh_node)
139 batadv_neigh_node_free_ref(neigh_node);
140
141 return ret;
142 }
143
144 /**
145 * batadv_send_skb_push_fill_unicast - extend the buffer and initialize the
146 * common fields for unicast packets
147 * @skb: the skb carrying the unicast header to initialize
148 * @hdr_size: amount of bytes to push at the beginning of the skb
149 * @orig_node: the destination node
150 *
151 * Returns false if the buffer extension was not possible or true otherwise.
152 */
153 static bool
154 batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
155 struct batadv_orig_node *orig_node)
156 {
157 struct batadv_unicast_packet *unicast_packet;
158 uint8_t ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
159
160 if (batadv_skb_head_push(skb, hdr_size) < 0)
161 return false;
162
163 unicast_packet = (struct batadv_unicast_packet *)skb->data;
164 unicast_packet->version = BATADV_COMPAT_VERSION;
165 /* batman packet type: unicast */
166 unicast_packet->packet_type = BATADV_UNICAST;
167 /* set unicast ttl */
168 unicast_packet->ttl = BATADV_TTL;
169 /* copy the destination for faster routing */
170 memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN);
171 /* set the destination tt version number */
172 unicast_packet->ttvn = ttvn;
173
174 return true;
175 }
176
177 /**
178 * batadv_send_skb_prepare_unicast - encapsulate an skb with a unicast header
179 * @skb: the skb containing the payload to encapsulate
180 * @orig_node: the destination node
181 *
182 * Returns false if the payload could not be encapsulated or true otherwise.
183 */
184 static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
185 struct batadv_orig_node *orig_node)
186 {
187 size_t uni_size = sizeof(struct batadv_unicast_packet);
188
189 return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
190 }
191
192 /**
193 * batadv_send_skb_prepare_unicast_4addr - encapsulate an skb with a
194 * unicast 4addr header
195 * @bat_priv: the bat priv with all the soft interface information
196 * @skb: the skb containing the payload to encapsulate
197 * @orig_node: the destination node
198 * @packet_subtype: the unicast 4addr packet subtype to use
199 *
200 * Returns false if the payload could not be encapsulated or true otherwise.
201 */
202 bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
203 struct sk_buff *skb,
204 struct batadv_orig_node *orig,
205 int packet_subtype)
206 {
207 struct batadv_hard_iface *primary_if;
208 struct batadv_unicast_4addr_packet *uc_4addr_packet;
209 bool ret = false;
210
211 primary_if = batadv_primary_if_get_selected(bat_priv);
212 if (!primary_if)
213 goto out;
214
215 /* Pull the header space and fill the unicast_packet substructure.
216 * We can do that because the first member of the uc_4addr_packet
217 * is of type struct unicast_packet
218 */
219 if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
220 orig))
221 goto out;
222
223 uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
224 uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
225 memcpy(uc_4addr_packet->src, primary_if->net_dev->dev_addr, ETH_ALEN);
226 uc_4addr_packet->subtype = packet_subtype;
227 uc_4addr_packet->reserved = 0;
228
229 ret = true;
230 out:
231 if (primary_if)
232 batadv_hardif_free_ref(primary_if);
233 return ret;
234 }
235
236 /**
237 * batadv_send_skb_unicast - encapsulate and send an skb via unicast
238 * @bat_priv: the bat priv with all the soft interface information
239 * @skb: payload to send
240 * @packet_type: the batman unicast packet type to use
241 * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
242 * 4addr packets)
243 * @orig_node: the originator to send the packet to
244 * @vid: the vid to be used to search the translation table
245 *
246 * Wrap the given skb into a batman-adv unicast or unicast-4addr header
247 * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
248 * as packet_type. Then send this frame to the given orig_node and release a
249 * reference to this orig_node.
250 *
251 * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
252 */
253 static int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
254 struct sk_buff *skb, int packet_type,
255 int packet_subtype,
256 struct batadv_orig_node *orig_node,
257 unsigned short vid)
258 {
259 struct ethhdr *ethhdr;
260 struct batadv_unicast_packet *unicast_packet;
261 int ret = NET_XMIT_DROP, hdr_size;
262
263 if (!orig_node)
264 goto out;
265
266 switch (packet_type) {
267 case BATADV_UNICAST:
268 if (!batadv_send_skb_prepare_unicast(skb, orig_node))
269 goto out;
270
271 hdr_size = sizeof(*unicast_packet);
272 break;
273 case BATADV_UNICAST_4ADDR:
274 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
275 orig_node,
276 packet_subtype))
277 goto out;
278
279 hdr_size = sizeof(struct batadv_unicast_4addr_packet);
280 break;
281 default:
282 /* this function supports UNICAST and UNICAST_4ADDR only. It
283 * should never be invoked with any other packet type
284 */
285 goto out;
286 }
287
288 ethhdr = (struct ethhdr *)(skb->data + hdr_size);
289 unicast_packet = (struct batadv_unicast_packet *)skb->data;
290
291 /* inform the destination node that we are still missing a correct route
292 * for this client. The destination will receive this packet and will
293 * try to reroute it because the ttvn contained in the header is less
294 * than the current one
295 */
296 if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
297 unicast_packet->ttvn = unicast_packet->ttvn - 1;
298
299 if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
300 ret = NET_XMIT_SUCCESS;
301
302 out:
303 if (orig_node)
304 batadv_orig_node_free_ref(orig_node);
305 if (ret == NET_XMIT_DROP)
306 kfree_skb(skb);
307 return ret;
308 }
309
310 /**
311 * batadv_send_skb_via_tt_generic - send an skb via TT lookup
312 * @bat_priv: the bat priv with all the soft interface information
313 * @skb: payload to send
314 * @packet_type: the batman unicast packet type to use
315 * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
316 * 4addr packets)
317 * @vid: the vid to be used to search the translation table
318 *
319 * Look up the recipient node for the destination address in the ethernet
320 * header via the translation table. Wrap the given skb into a batman-adv
321 * unicast or unicast-4addr header depending on whether BATADV_UNICAST or
322 * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
323 * to the according destination node.
324 *
325 * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
326 */
327 int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
328 struct sk_buff *skb, int packet_type,
329 int packet_subtype, unsigned short vid)
330 {
331 struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
332 struct batadv_orig_node *orig_node;
333
334 orig_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
335 ethhdr->h_dest, vid);
336 return batadv_send_skb_unicast(bat_priv, skb, packet_type,
337 packet_subtype, orig_node, vid);
338 }
339
340 /**
341 * batadv_send_skb_via_gw - send an skb via gateway lookup
342 * @bat_priv: the bat priv with all the soft interface information
343 * @skb: payload to send
344 * @vid: the vid to be used to search the translation table
345 *
346 * Look up the currently selected gateway. Wrap the given skb into a batman-adv
347 * unicast header and send this frame to this gateway node.
348 *
349 * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
350 */
351 int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
352 unsigned short vid)
353 {
354 struct batadv_orig_node *orig_node;
355
356 orig_node = batadv_gw_get_selected_orig(bat_priv);
357 return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
358 orig_node, vid);
359 }
360
361 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
362 {
363 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
364
365 if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
366 (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
367 return;
368
369 /* the interface gets activated here to avoid race conditions between
370 * the moment of activating the interface in
371 * hardif_activate_interface() where the originator mac is set and
372 * outdated packets (especially uninitialized mac addresses) in the
373 * packet queue
374 */
375 if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
376 hard_iface->if_status = BATADV_IF_ACTIVE;
377
378 bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
379 }
380
381 static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
382 {
383 if (forw_packet->skb)
384 kfree_skb(forw_packet->skb);
385 if (forw_packet->if_incoming)
386 batadv_hardif_free_ref(forw_packet->if_incoming);
387 kfree(forw_packet);
388 }
389
390 static void
391 _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
392 struct batadv_forw_packet *forw_packet,
393 unsigned long send_time)
394 {
395 /* add new packet to packet list */
396 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
397 hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
398 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
399
400 /* start timer for this packet */
401 queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
402 send_time);
403 }
404
405 /* add a broadcast packet to the queue and setup timers. broadcast packets
406 * are sent multiple times to increase probability for being received.
407 *
408 * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
409 * errors.
410 *
411 * The skb is not consumed, so the caller should make sure that the
412 * skb is freed.
413 */
414 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
415 const struct sk_buff *skb,
416 unsigned long delay)
417 {
418 struct batadv_hard_iface *primary_if = NULL;
419 struct batadv_forw_packet *forw_packet;
420 struct batadv_bcast_packet *bcast_packet;
421 struct sk_buff *newskb;
422
423 if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
424 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
425 "bcast packet queue full\n");
426 goto out;
427 }
428
429 primary_if = batadv_primary_if_get_selected(bat_priv);
430 if (!primary_if)
431 goto out_and_inc;
432
433 forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
434
435 if (!forw_packet)
436 goto out_and_inc;
437
438 newskb = skb_copy(skb, GFP_ATOMIC);
439 if (!newskb)
440 goto packet_free;
441
442 /* as we have a copy now, it is safe to decrease the TTL */
443 bcast_packet = (struct batadv_bcast_packet *)newskb->data;
444 bcast_packet->ttl--;
445
446 skb_reset_mac_header(newskb);
447
448 forw_packet->skb = newskb;
449 forw_packet->if_incoming = primary_if;
450
451 /* how often did we send the bcast packet ? */
452 forw_packet->num_packets = 0;
453
454 INIT_DELAYED_WORK(&forw_packet->delayed_work,
455 batadv_send_outstanding_bcast_packet);
456
457 _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
458 return NETDEV_TX_OK;
459
460 packet_free:
461 kfree(forw_packet);
462 out_and_inc:
463 atomic_inc(&bat_priv->bcast_queue_left);
464 out:
465 if (primary_if)
466 batadv_hardif_free_ref(primary_if);
467 return NETDEV_TX_BUSY;
468 }
469
470 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
471 {
472 struct batadv_hard_iface *hard_iface;
473 struct delayed_work *delayed_work;
474 struct batadv_forw_packet *forw_packet;
475 struct sk_buff *skb1;
476 struct net_device *soft_iface;
477 struct batadv_priv *bat_priv;
478
479 delayed_work = container_of(work, struct delayed_work, work);
480 forw_packet = container_of(delayed_work, struct batadv_forw_packet,
481 delayed_work);
482 soft_iface = forw_packet->if_incoming->soft_iface;
483 bat_priv = netdev_priv(soft_iface);
484
485 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
486 hlist_del(&forw_packet->list);
487 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
488
489 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
490 goto out;
491
492 if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
493 goto out;
494
495 /* rebroadcast packet */
496 rcu_read_lock();
497 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
498 if (hard_iface->soft_iface != soft_iface)
499 continue;
500
501 if (forw_packet->num_packets >= hard_iface->num_bcasts)
502 continue;
503
504 /* send a copy of the saved skb */
505 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
506 if (skb1)
507 batadv_send_skb_packet(skb1, hard_iface,
508 batadv_broadcast_addr);
509 }
510 rcu_read_unlock();
511
512 forw_packet->num_packets++;
513
514 /* if we still have some more bcasts to send */
515 if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) {
516 _batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
517 msecs_to_jiffies(5));
518 return;
519 }
520
521 out:
522 batadv_forw_packet_free(forw_packet);
523 atomic_inc(&bat_priv->bcast_queue_left);
524 }
525
526 void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
527 {
528 struct delayed_work *delayed_work;
529 struct batadv_forw_packet *forw_packet;
530 struct batadv_priv *bat_priv;
531
532 delayed_work = container_of(work, struct delayed_work, work);
533 forw_packet = container_of(delayed_work, struct batadv_forw_packet,
534 delayed_work);
535 bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
536 spin_lock_bh(&bat_priv->forw_bat_list_lock);
537 hlist_del(&forw_packet->list);
538 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
539
540 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
541 goto out;
542
543 bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
544
545 /* we have to have at least one packet in the queue
546 * to determine the queues wake up time unless we are
547 * shutting down
548 */
549 if (forw_packet->own)
550 batadv_schedule_bat_ogm(forw_packet->if_incoming);
551
552 out:
553 /* don't count own packet */
554 if (!forw_packet->own)
555 atomic_inc(&bat_priv->batman_queue_left);
556
557 batadv_forw_packet_free(forw_packet);
558 }
559
560 void
561 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
562 const struct batadv_hard_iface *hard_iface)
563 {
564 struct batadv_forw_packet *forw_packet;
565 struct hlist_node *safe_tmp_node;
566 bool pending;
567
568 if (hard_iface)
569 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
570 "purge_outstanding_packets(): %s\n",
571 hard_iface->net_dev->name);
572 else
573 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
574 "purge_outstanding_packets()\n");
575
576 /* free bcast list */
577 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
578 hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
579 &bat_priv->forw_bcast_list, list) {
580 /* if purge_outstanding_packets() was called with an argument
581 * we delete only packets belonging to the given interface
582 */
583 if ((hard_iface) &&
584 (forw_packet->if_incoming != hard_iface))
585 continue;
586
587 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
588
589 /* batadv_send_outstanding_bcast_packet() will lock the list to
590 * delete the item from the list
591 */
592 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
593 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
594
595 if (pending) {
596 hlist_del(&forw_packet->list);
597 batadv_forw_packet_free(forw_packet);
598 }
599 }
600 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
601
602 /* free batman packet list */
603 spin_lock_bh(&bat_priv->forw_bat_list_lock);
604 hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
605 &bat_priv->forw_bat_list, list) {
606 /* if purge_outstanding_packets() was called with an argument
607 * we delete only packets belonging to the given interface
608 */
609 if ((hard_iface) &&
610 (forw_packet->if_incoming != hard_iface))
611 continue;
612
613 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
614
615 /* send_outstanding_bat_packet() will lock the list to
616 * delete the item from the list
617 */
618 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
619 spin_lock_bh(&bat_priv->forw_bat_list_lock);
620
621 if (pending) {
622 hlist_del(&forw_packet->list);
623 batadv_forw_packet_free(forw_packet);
624 }
625 }
626 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
627 }
628
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