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1/* Copyright (C) 2007-2014 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, see <http://www.gnu.org/licenses/>.
16 */
17
18#include "main.h"
19#include "distributed-arp-table.h"
20#include "send.h"
21#include "routing.h"
22#include "translation-table.h"
23#include "soft-interface.h"
24#include "hard-interface.h"
25#include "gateway_common.h"
26#include "gateway_client.h"
27#include "originator.h"
28#include "network-coding.h"
29#include "fragmentation.h"
30#include "multicast.h"
31
32static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
33
34/* send out an already prepared packet to the given address via the
35 * specified batman interface
36 */
37int batadv_send_skb_packet(struct sk_buff *skb,
38 struct batadv_hard_iface *hard_iface,
39 const uint8_t *dst_addr)
40{
41 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
42 struct ethhdr *ethhdr;
43
44 if (hard_iface->if_status != BATADV_IF_ACTIVE)
45 goto send_skb_err;
46
47 if (unlikely(!hard_iface->net_dev))
48 goto send_skb_err;
49
50 if (!(hard_iface->net_dev->flags & IFF_UP)) {
51 pr_warn("Interface %s is not up - can't send packet via that interface!\n",
52 hard_iface->net_dev->name);
53 goto send_skb_err;
54 }
55
56 /* push to the ethernet header. */
57 if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
58 goto send_skb_err;
59
60 skb_reset_mac_header(skb);
61
62 ethhdr = eth_hdr(skb);
63 ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr);
64 ether_addr_copy(ethhdr->h_dest, dst_addr);
65 ethhdr->h_proto = htons(ETH_P_BATMAN);
66
67 skb_set_network_header(skb, ETH_HLEN);
68 skb->protocol = htons(ETH_P_BATMAN);
69
70 skb->dev = hard_iface->net_dev;
71
72 /* Save a clone of the skb to use when decoding coded packets */
73 batadv_nc_skb_store_for_decoding(bat_priv, skb);
74
75 /* dev_queue_xmit() returns a negative result on error. However on
76 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
77 * (which is > 0). This will not be treated as an error.
78 */
79 return dev_queue_xmit(skb);
80send_skb_err:
81 kfree_skb(skb);
82 return NET_XMIT_DROP;
83}
84
85/**
86 * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
87 * @skb: Packet to be transmitted.
88 * @orig_node: Final destination of the packet.
89 * @recv_if: Interface used when receiving the packet (can be NULL).
90 *
91 * Looks up the best next-hop towards the passed originator and passes the
92 * skb on for preparation of MAC header. If the packet originated from this
93 * host, NULL can be passed as recv_if and no interface alternating is
94 * attempted.
95 *
96 * Returns NET_XMIT_SUCCESS on success, NET_XMIT_DROP on failure, or
97 * NET_XMIT_POLICED if the skb is buffered for later transmit.
98 */
99int batadv_send_skb_to_orig(struct sk_buff *skb,
100 struct batadv_orig_node *orig_node,
101 struct batadv_hard_iface *recv_if)
102{
103 struct batadv_priv *bat_priv = orig_node->bat_priv;
104 struct batadv_neigh_node *neigh_node;
105 int ret = NET_XMIT_DROP;
106
107 /* batadv_find_router() increases neigh_nodes refcount if found. */
108 neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
109 if (!neigh_node)
110 goto out;
111
112 /* Check if the skb is too large to send in one piece and fragment
113 * it if needed.
114 */
115 if (atomic_read(&bat_priv->fragmentation) &&
116 skb->len > neigh_node->if_incoming->net_dev->mtu) {
117 /* Fragment and send packet. */
118 if (batadv_frag_send_packet(skb, orig_node, neigh_node))
119 ret = NET_XMIT_SUCCESS;
120
121 goto out;
122 }
123
124 /* try to network code the packet, if it is received on an interface
125 * (i.e. being forwarded). If the packet originates from this node or if
126 * network coding fails, then send the packet as usual.
127 */
128 if (recv_if && batadv_nc_skb_forward(skb, neigh_node)) {
129 ret = NET_XMIT_POLICED;
130 } else {
131 batadv_send_skb_packet(skb, neigh_node->if_incoming,
132 neigh_node->addr);
133 ret = NET_XMIT_SUCCESS;
134 }
135
136out:
137 if (neigh_node)
138 batadv_neigh_node_free_ref(neigh_node);
139
140 return ret;
141}
142
143/**
144 * batadv_send_skb_push_fill_unicast - extend the buffer and initialize the
145 * common fields for unicast packets
146 * @skb: the skb carrying the unicast header to initialize
147 * @hdr_size: amount of bytes to push at the beginning of the skb
148 * @orig_node: the destination node
149 *
150 * Returns false if the buffer extension was not possible or true otherwise.
151 */
152static bool
153batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
154 struct batadv_orig_node *orig_node)
155{
156 struct batadv_unicast_packet *unicast_packet;
157 uint8_t ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
158
159 if (batadv_skb_head_push(skb, hdr_size) < 0)
160 return false;
161
162 unicast_packet = (struct batadv_unicast_packet *)skb->data;
163 unicast_packet->version = BATADV_COMPAT_VERSION;
164 /* batman packet type: unicast */
165 unicast_packet->packet_type = BATADV_UNICAST;
166 /* set unicast ttl */
167 unicast_packet->ttl = BATADV_TTL;
168 /* copy the destination for faster routing */
169 ether_addr_copy(unicast_packet->dest, orig_node->orig);
170 /* set the destination tt version number */
171 unicast_packet->ttvn = ttvn;
172
173 return true;
174}
175
176/**
177 * batadv_send_skb_prepare_unicast - encapsulate an skb with a unicast header
178 * @skb: the skb containing the payload to encapsulate
179 * @orig_node: the destination node
180 *
181 * Returns false if the payload could not be encapsulated or true otherwise.
182 */
183static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
184 struct batadv_orig_node *orig_node)
185{
186 size_t uni_size = sizeof(struct batadv_unicast_packet);
187
188 return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
189}
190
191/**
192 * batadv_send_skb_prepare_unicast_4addr - encapsulate an skb with a
193 * unicast 4addr header
194 * @bat_priv: the bat priv with all the soft interface information
195 * @skb: the skb containing the payload to encapsulate
196 * @orig_node: the destination node
197 * @packet_subtype: the unicast 4addr packet subtype to use
198 *
199 * Returns false if the payload could not be encapsulated or true otherwise.
200 */
201bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
202 struct sk_buff *skb,
203 struct batadv_orig_node *orig,
204 int packet_subtype)
205{
206 struct batadv_hard_iface *primary_if;
207 struct batadv_unicast_4addr_packet *uc_4addr_packet;
208 bool ret = false;
209
210 primary_if = batadv_primary_if_get_selected(bat_priv);
211 if (!primary_if)
212 goto out;
213
214 /* Pull the header space and fill the unicast_packet substructure.
215 * We can do that because the first member of the uc_4addr_packet
216 * is of type struct unicast_packet
217 */
218 if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
219 orig))
220 goto out;
221
222 uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
223 uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
224 ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr);
225 uc_4addr_packet->subtype = packet_subtype;
226 uc_4addr_packet->reserved = 0;
227
228 ret = true;
229out:
230 if (primary_if)
231 batadv_hardif_free_ref(primary_if);
232 return ret;
233}
234
235/**
236 * batadv_send_skb_unicast - encapsulate and send an skb via unicast
237 * @bat_priv: the bat priv with all the soft interface information
238 * @skb: payload to send
239 * @packet_type: the batman unicast packet type to use
240 * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
241 * 4addr packets)
242 * @orig_node: the originator to send the packet to
243 * @vid: the vid to be used to search the translation table
244 *
245 * Wrap the given skb into a batman-adv unicast or unicast-4addr header
246 * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
247 * as packet_type. Then send this frame to the given orig_node and release a
248 * reference to this orig_node.
249 *
250 * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
251 */
252int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
253 struct sk_buff *skb, int packet_type,
254 int packet_subtype,
255 struct batadv_orig_node *orig_node,
256 unsigned short vid)
257{
258 struct ethhdr *ethhdr;
259 struct batadv_unicast_packet *unicast_packet;
260 int ret = NET_XMIT_DROP;
261
262 if (!orig_node)
263 goto out;
264
265 switch (packet_type) {
266 case BATADV_UNICAST:
267 if (!batadv_send_skb_prepare_unicast(skb, orig_node))
268 goto out;
269 break;
270 case BATADV_UNICAST_4ADDR:
271 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
272 orig_node,
273 packet_subtype))
274 goto out;
275 break;
276 default:
277 /* this function supports UNICAST and UNICAST_4ADDR only. It
278 * should never be invoked with any other packet type
279 */
280 goto out;
281 }
282
283 /* skb->data might have been reallocated by
284 * batadv_send_skb_prepare_unicast{,_4addr}()
285 */
286 ethhdr = eth_hdr(skb);
287 unicast_packet = (struct batadv_unicast_packet *)skb->data;
288
289 /* inform the destination node that we are still missing a correct route
290 * for this client. The destination will receive this packet and will
291 * try to reroute it because the ttvn contained in the header is less
292 * than the current one
293 */
294 if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
295 unicast_packet->ttvn = unicast_packet->ttvn - 1;
296
297 if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
298 ret = NET_XMIT_SUCCESS;
299
300out:
301 if (orig_node)
302 batadv_orig_node_free_ref(orig_node);
303 if (ret == NET_XMIT_DROP)
304 kfree_skb(skb);
305 return ret;
306}
307
308/**
309 * batadv_send_skb_via_tt_generic - send an skb via TT lookup
310 * @bat_priv: the bat priv with all the soft interface information
311 * @skb: payload to send
312 * @packet_type: the batman unicast packet type to use
313 * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
314 * 4addr packets)
315 * @dst_hint: can be used to override the destination contained in the skb
316 * @vid: the vid to be used to search the translation table
317 *
318 * Look up the recipient node for the destination address in the ethernet
319 * header via the translation table. Wrap the given skb into a batman-adv
320 * unicast or unicast-4addr header depending on whether BATADV_UNICAST or
321 * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
322 * to the according destination node.
323 *
324 * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
325 */
326int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
327 struct sk_buff *skb, int packet_type,
328 int packet_subtype, uint8_t *dst_hint,
329 unsigned short vid)
330{
331 struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
332 struct batadv_orig_node *orig_node;
333 uint8_t *src, *dst;
334
335 src = ethhdr->h_source;
336 dst = ethhdr->h_dest;
337
338 /* if we got an hint! let's send the packet to this client (if any) */
339 if (dst_hint) {
340 src = NULL;
341 dst = dst_hint;
342 }
343 orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
344
345 return batadv_send_skb_unicast(bat_priv, skb, packet_type,
346 packet_subtype, orig_node, vid);
347}
348
349/**
350 * batadv_send_skb_via_gw - send an skb via gateway lookup
351 * @bat_priv: the bat priv with all the soft interface information
352 * @skb: payload to send
353 * @vid: the vid to be used to search the translation table
354 *
355 * Look up the currently selected gateway. Wrap the given skb into a batman-adv
356 * unicast header and send this frame to this gateway node.
357 *
358 * Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
359 */
360int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
361 unsigned short vid)
362{
363 struct batadv_orig_node *orig_node;
364
365 orig_node = batadv_gw_get_selected_orig(bat_priv);
366 return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
367 orig_node, vid);
368}
369
370void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
371{
372 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
373
374 if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
375 (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
376 return;
377
378 /* the interface gets activated here to avoid race conditions between
379 * the moment of activating the interface in
380 * hardif_activate_interface() where the originator mac is set and
381 * outdated packets (especially uninitialized mac addresses) in the
382 * packet queue
383 */
384 if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
385 hard_iface->if_status = BATADV_IF_ACTIVE;
386
387 bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
388}
389
390static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
391{
392 if (forw_packet->skb)
393 kfree_skb(forw_packet->skb);
394 if (forw_packet->if_incoming)
395 batadv_hardif_free_ref(forw_packet->if_incoming);
396 if (forw_packet->if_outgoing)
397 batadv_hardif_free_ref(forw_packet->if_outgoing);
398 kfree(forw_packet);
399}
400
401static void
402_batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
403 struct batadv_forw_packet *forw_packet,
404 unsigned long send_time)
405{
406 /* add new packet to packet list */
407 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
408 hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
409 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
410
411 /* start timer for this packet */
412 queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
413 send_time);
414}
415
416/* add a broadcast packet to the queue and setup timers. broadcast packets
417 * are sent multiple times to increase probability for being received.
418 *
419 * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
420 * errors.
421 *
422 * The skb is not consumed, so the caller should make sure that the
423 * skb is freed.
424 */
425int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
426 const struct sk_buff *skb,
427 unsigned long delay)
428{
429 struct batadv_hard_iface *primary_if = NULL;
430 struct batadv_forw_packet *forw_packet;
431 struct batadv_bcast_packet *bcast_packet;
432 struct sk_buff *newskb;
433
434 if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
435 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
436 "bcast packet queue full\n");
437 goto out;
438 }
439
440 primary_if = batadv_primary_if_get_selected(bat_priv);
441 if (!primary_if)
442 goto out_and_inc;
443
444 forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
445
446 if (!forw_packet)
447 goto out_and_inc;
448
449 newskb = skb_copy(skb, GFP_ATOMIC);
450 if (!newskb)
451 goto packet_free;
452
453 /* as we have a copy now, it is safe to decrease the TTL */
454 bcast_packet = (struct batadv_bcast_packet *)newskb->data;
455 bcast_packet->ttl--;
456
457 skb_reset_mac_header(newskb);
458
459 forw_packet->skb = newskb;
460 forw_packet->if_incoming = primary_if;
461 forw_packet->if_outgoing = NULL;
462
463 /* how often did we send the bcast packet ? */
464 forw_packet->num_packets = 0;
465
466 INIT_DELAYED_WORK(&forw_packet->delayed_work,
467 batadv_send_outstanding_bcast_packet);
468
469 _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
470 return NETDEV_TX_OK;
471
472packet_free:
473 kfree(forw_packet);
474out_and_inc:
475 atomic_inc(&bat_priv->bcast_queue_left);
476out:
477 if (primary_if)
478 batadv_hardif_free_ref(primary_if);
479 return NETDEV_TX_BUSY;
480}
481
482static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
483{
484 struct batadv_hard_iface *hard_iface;
485 struct delayed_work *delayed_work;
486 struct batadv_forw_packet *forw_packet;
487 struct sk_buff *skb1;
488 struct net_device *soft_iface;
489 struct batadv_priv *bat_priv;
490
491 delayed_work = container_of(work, struct delayed_work, work);
492 forw_packet = container_of(delayed_work, struct batadv_forw_packet,
493 delayed_work);
494 soft_iface = forw_packet->if_incoming->soft_iface;
495 bat_priv = netdev_priv(soft_iface);
496
497 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
498 hlist_del(&forw_packet->list);
499 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
500
501 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
502 goto out;
503
504 if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
505 goto out;
506
507 /* rebroadcast packet */
508 rcu_read_lock();
509 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
510 if (hard_iface->soft_iface != soft_iface)
511 continue;
512
513 if (forw_packet->num_packets >= hard_iface->num_bcasts)
514 continue;
515
516 /* send a copy of the saved skb */
517 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
518 if (skb1)
519 batadv_send_skb_packet(skb1, hard_iface,
520 batadv_broadcast_addr);
521 }
522 rcu_read_unlock();
523
524 forw_packet->num_packets++;
525
526 /* if we still have some more bcasts to send */
527 if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) {
528 _batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
529 msecs_to_jiffies(5));
530 return;
531 }
532
533out:
534 batadv_forw_packet_free(forw_packet);
535 atomic_inc(&bat_priv->bcast_queue_left);
536}
537
538void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
539{
540 struct delayed_work *delayed_work;
541 struct batadv_forw_packet *forw_packet;
542 struct batadv_priv *bat_priv;
543
544 delayed_work = container_of(work, struct delayed_work, work);
545 forw_packet = container_of(delayed_work, struct batadv_forw_packet,
546 delayed_work);
547 bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
548 spin_lock_bh(&bat_priv->forw_bat_list_lock);
549 hlist_del(&forw_packet->list);
550 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
551
552 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
553 goto out;
554
555 bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
556
557 /* we have to have at least one packet in the queue to determine the
558 * queues wake up time unless we are shutting down.
559 *
560 * only re-schedule if this is the "original" copy, e.g. the OGM of the
561 * primary interface should only be rescheduled once per period, but
562 * this function will be called for the forw_packet instances of the
563 * other secondary interfaces as well.
564 */
565 if (forw_packet->own &&
566 forw_packet->if_incoming == forw_packet->if_outgoing)
567 batadv_schedule_bat_ogm(forw_packet->if_incoming);
568
569out:
570 /* don't count own packet */
571 if (!forw_packet->own)
572 atomic_inc(&bat_priv->batman_queue_left);
573
574 batadv_forw_packet_free(forw_packet);
575}
576
577void
578batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
579 const struct batadv_hard_iface *hard_iface)
580{
581 struct batadv_forw_packet *forw_packet;
582 struct hlist_node *safe_tmp_node;
583 bool pending;
584
585 if (hard_iface)
586 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
587 "purge_outstanding_packets(): %s\n",
588 hard_iface->net_dev->name);
589 else
590 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
591 "purge_outstanding_packets()\n");
592
593 /* free bcast list */
594 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
595 hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
596 &bat_priv->forw_bcast_list, list) {
597 /* if purge_outstanding_packets() was called with an argument
598 * we delete only packets belonging to the given interface
599 */
600 if ((hard_iface) &&
601 (forw_packet->if_incoming != hard_iface))
602 continue;
603
604 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
605
606 /* batadv_send_outstanding_bcast_packet() will lock the list to
607 * delete the item from the list
608 */
609 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
610 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
611
612 if (pending) {
613 hlist_del(&forw_packet->list);
614 batadv_forw_packet_free(forw_packet);
615 }
616 }
617 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
618
619 /* free batman packet list */
620 spin_lock_bh(&bat_priv->forw_bat_list_lock);
621 hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
622 &bat_priv->forw_bat_list, list) {
623 /* if purge_outstanding_packets() was called with an argument
624 * we delete only packets belonging to the given interface
625 */
626 if ((hard_iface) &&
627 (forw_packet->if_incoming != hard_iface) &&
628 (forw_packet->if_outgoing != hard_iface))
629 continue;
630
631 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
632
633 /* send_outstanding_bat_packet() will lock the list to
634 * delete the item from the list
635 */
636 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
637 spin_lock_bh(&bat_priv->forw_bat_list_lock);
638
639 if (pending) {
640 hlist_del(&forw_packet->list);
641 batadv_forw_packet_free(forw_packet);
642 }
643 }
644 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
645}
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (C) B.A.T.M.A.N. contributors:
3 *
4 * Marek Lindner, Simon Wunderlich
5 */
6
7#include "send.h"
8#include "main.h"
9
10#include <linux/atomic.h>
11#include <linux/bug.h>
12#include <linux/byteorder/generic.h>
13#include <linux/errno.h>
14#include <linux/etherdevice.h>
15#include <linux/gfp.h>
16#include <linux/if.h>
17#include <linux/if_ether.h>
18#include <linux/jiffies.h>
19#include <linux/kernel.h>
20#include <linux/kref.h>
21#include <linux/list.h>
22#include <linux/netdevice.h>
23#include <linux/printk.h>
24#include <linux/rculist.h>
25#include <linux/rcupdate.h>
26#include <linux/skbuff.h>
27#include <linux/slab.h>
28#include <linux/spinlock.h>
29#include <linux/stddef.h>
30#include <linux/workqueue.h>
31
32#include "distributed-arp-table.h"
33#include "fragmentation.h"
34#include "gateway_client.h"
35#include "hard-interface.h"
36#include "log.h"
37#include "network-coding.h"
38#include "originator.h"
39#include "routing.h"
40#include "soft-interface.h"
41#include "translation-table.h"
42
43static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
44
45/**
46 * batadv_send_skb_packet() - send an already prepared packet
47 * @skb: the packet to send
48 * @hard_iface: the interface to use to send the broadcast packet
49 * @dst_addr: the payload destination
50 *
51 * Send out an already prepared packet to the given neighbor or broadcast it
52 * using the specified interface. Either hard_iface or neigh_node must be not
53 * NULL.
54 * If neigh_node is NULL, then the packet is broadcasted using hard_iface,
55 * otherwise it is sent as unicast to the given neighbor.
56 *
57 * Regardless of the return value, the skb is consumed.
58 *
59 * Return: A negative errno code is returned on a failure. A success does not
60 * guarantee the frame will be transmitted as it may be dropped due
61 * to congestion or traffic shaping.
62 */
63int batadv_send_skb_packet(struct sk_buff *skb,
64 struct batadv_hard_iface *hard_iface,
65 const u8 *dst_addr)
66{
67 struct batadv_priv *bat_priv;
68 struct ethhdr *ethhdr;
69 int ret;
70
71 bat_priv = netdev_priv(hard_iface->soft_iface);
72
73 if (hard_iface->if_status != BATADV_IF_ACTIVE)
74 goto send_skb_err;
75
76 if (unlikely(!hard_iface->net_dev))
77 goto send_skb_err;
78
79 if (!(hard_iface->net_dev->flags & IFF_UP)) {
80 pr_warn("Interface %s is not up - can't send packet via that interface!\n",
81 hard_iface->net_dev->name);
82 goto send_skb_err;
83 }
84
85 /* push to the ethernet header. */
86 if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
87 goto send_skb_err;
88
89 skb_reset_mac_header(skb);
90
91 ethhdr = eth_hdr(skb);
92 ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr);
93 ether_addr_copy(ethhdr->h_dest, dst_addr);
94 ethhdr->h_proto = htons(ETH_P_BATMAN);
95
96 skb_set_network_header(skb, ETH_HLEN);
97 skb->protocol = htons(ETH_P_BATMAN);
98
99 skb->dev = hard_iface->net_dev;
100
101 /* Save a clone of the skb to use when decoding coded packets */
102 batadv_nc_skb_store_for_decoding(bat_priv, skb);
103
104 /* dev_queue_xmit() returns a negative result on error. However on
105 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
106 * (which is > 0). This will not be treated as an error.
107 */
108 ret = dev_queue_xmit(skb);
109 return net_xmit_eval(ret);
110send_skb_err:
111 kfree_skb(skb);
112 return NET_XMIT_DROP;
113}
114
115/**
116 * batadv_send_broadcast_skb() - Send broadcast packet via hard interface
117 * @skb: packet to be transmitted (with batadv header and no outer eth header)
118 * @hard_iface: outgoing interface
119 *
120 * Return: A negative errno code is returned on a failure. A success does not
121 * guarantee the frame will be transmitted as it may be dropped due
122 * to congestion or traffic shaping.
123 */
124int batadv_send_broadcast_skb(struct sk_buff *skb,
125 struct batadv_hard_iface *hard_iface)
126{
127 return batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr);
128}
129
130/**
131 * batadv_send_unicast_skb() - Send unicast packet to neighbor
132 * @skb: packet to be transmitted (with batadv header and no outer eth header)
133 * @neigh: neighbor which is used as next hop to destination
134 *
135 * Return: A negative errno code is returned on a failure. A success does not
136 * guarantee the frame will be transmitted as it may be dropped due
137 * to congestion or traffic shaping.
138 */
139int batadv_send_unicast_skb(struct sk_buff *skb,
140 struct batadv_neigh_node *neigh)
141{
142#ifdef CONFIG_BATMAN_ADV_BATMAN_V
143 struct batadv_hardif_neigh_node *hardif_neigh;
144#endif
145 int ret;
146
147 ret = batadv_send_skb_packet(skb, neigh->if_incoming, neigh->addr);
148
149#ifdef CONFIG_BATMAN_ADV_BATMAN_V
150 hardif_neigh = batadv_hardif_neigh_get(neigh->if_incoming, neigh->addr);
151
152 if (hardif_neigh && ret != NET_XMIT_DROP)
153 hardif_neigh->bat_v.last_unicast_tx = jiffies;
154
155 if (hardif_neigh)
156 batadv_hardif_neigh_put(hardif_neigh);
157#endif
158
159 return ret;
160}
161
162/**
163 * batadv_send_skb_to_orig() - Lookup next-hop and transmit skb.
164 * @skb: Packet to be transmitted.
165 * @orig_node: Final destination of the packet.
166 * @recv_if: Interface used when receiving the packet (can be NULL).
167 *
168 * Looks up the best next-hop towards the passed originator and passes the
169 * skb on for preparation of MAC header. If the packet originated from this
170 * host, NULL can be passed as recv_if and no interface alternating is
171 * attempted.
172 *
173 * Return: negative errno code on a failure, -EINPROGRESS if the skb is
174 * buffered for later transmit or the NET_XMIT status returned by the
175 * lower routine if the packet has been passed down.
176 */
177int batadv_send_skb_to_orig(struct sk_buff *skb,
178 struct batadv_orig_node *orig_node,
179 struct batadv_hard_iface *recv_if)
180{
181 struct batadv_priv *bat_priv = orig_node->bat_priv;
182 struct batadv_neigh_node *neigh_node;
183 int ret;
184
185 /* batadv_find_router() increases neigh_nodes refcount if found. */
186 neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
187 if (!neigh_node) {
188 ret = -EINVAL;
189 goto free_skb;
190 }
191
192 /* Check if the skb is too large to send in one piece and fragment
193 * it if needed.
194 */
195 if (atomic_read(&bat_priv->fragmentation) &&
196 skb->len > neigh_node->if_incoming->net_dev->mtu) {
197 /* Fragment and send packet. */
198 ret = batadv_frag_send_packet(skb, orig_node, neigh_node);
199 /* skb was consumed */
200 skb = NULL;
201
202 goto put_neigh_node;
203 }
204
205 /* try to network code the packet, if it is received on an interface
206 * (i.e. being forwarded). If the packet originates from this node or if
207 * network coding fails, then send the packet as usual.
208 */
209 if (recv_if && batadv_nc_skb_forward(skb, neigh_node))
210 ret = -EINPROGRESS;
211 else
212 ret = batadv_send_unicast_skb(skb, neigh_node);
213
214 /* skb was consumed */
215 skb = NULL;
216
217put_neigh_node:
218 batadv_neigh_node_put(neigh_node);
219free_skb:
220 kfree_skb(skb);
221
222 return ret;
223}
224
225/**
226 * batadv_send_skb_push_fill_unicast() - extend the buffer and initialize the
227 * common fields for unicast packets
228 * @skb: the skb carrying the unicast header to initialize
229 * @hdr_size: amount of bytes to push at the beginning of the skb
230 * @orig_node: the destination node
231 *
232 * Return: false if the buffer extension was not possible or true otherwise.
233 */
234static bool
235batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
236 struct batadv_orig_node *orig_node)
237{
238 struct batadv_unicast_packet *unicast_packet;
239 u8 ttvn = (u8)atomic_read(&orig_node->last_ttvn);
240
241 if (batadv_skb_head_push(skb, hdr_size) < 0)
242 return false;
243
244 unicast_packet = (struct batadv_unicast_packet *)skb->data;
245 unicast_packet->version = BATADV_COMPAT_VERSION;
246 /* batman packet type: unicast */
247 unicast_packet->packet_type = BATADV_UNICAST;
248 /* set unicast ttl */
249 unicast_packet->ttl = BATADV_TTL;
250 /* copy the destination for faster routing */
251 ether_addr_copy(unicast_packet->dest, orig_node->orig);
252 /* set the destination tt version number */
253 unicast_packet->ttvn = ttvn;
254
255 return true;
256}
257
258/**
259 * batadv_send_skb_prepare_unicast() - encapsulate an skb with a unicast header
260 * @skb: the skb containing the payload to encapsulate
261 * @orig_node: the destination node
262 *
263 * Return: false if the payload could not be encapsulated or true otherwise.
264 */
265static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
266 struct batadv_orig_node *orig_node)
267{
268 size_t uni_size = sizeof(struct batadv_unicast_packet);
269
270 return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
271}
272
273/**
274 * batadv_send_skb_prepare_unicast_4addr() - encapsulate an skb with a
275 * unicast 4addr header
276 * @bat_priv: the bat priv with all the soft interface information
277 * @skb: the skb containing the payload to encapsulate
278 * @orig: the destination node
279 * @packet_subtype: the unicast 4addr packet subtype to use
280 *
281 * Return: false if the payload could not be encapsulated or true otherwise.
282 */
283bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
284 struct sk_buff *skb,
285 struct batadv_orig_node *orig,
286 int packet_subtype)
287{
288 struct batadv_hard_iface *primary_if;
289 struct batadv_unicast_4addr_packet *uc_4addr_packet;
290 bool ret = false;
291
292 primary_if = batadv_primary_if_get_selected(bat_priv);
293 if (!primary_if)
294 goto out;
295
296 /* Pull the header space and fill the unicast_packet substructure.
297 * We can do that because the first member of the uc_4addr_packet
298 * is of type struct unicast_packet
299 */
300 if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
301 orig))
302 goto out;
303
304 uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
305 uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
306 ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr);
307 uc_4addr_packet->subtype = packet_subtype;
308 uc_4addr_packet->reserved = 0;
309
310 ret = true;
311out:
312 if (primary_if)
313 batadv_hardif_put(primary_if);
314 return ret;
315}
316
317/**
318 * batadv_send_skb_unicast() - encapsulate and send an skb via unicast
319 * @bat_priv: the bat priv with all the soft interface information
320 * @skb: payload to send
321 * @packet_type: the batman unicast packet type to use
322 * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
323 * 4addr packets)
324 * @orig_node: the originator to send the packet to
325 * @vid: the vid to be used to search the translation table
326 *
327 * Wrap the given skb into a batman-adv unicast or unicast-4addr header
328 * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
329 * as packet_type. Then send this frame to the given orig_node.
330 *
331 * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
332 */
333int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
334 struct sk_buff *skb, int packet_type,
335 int packet_subtype,
336 struct batadv_orig_node *orig_node,
337 unsigned short vid)
338{
339 struct batadv_unicast_packet *unicast_packet;
340 struct ethhdr *ethhdr;
341 int ret = NET_XMIT_DROP;
342
343 if (!orig_node)
344 goto out;
345
346 switch (packet_type) {
347 case BATADV_UNICAST:
348 if (!batadv_send_skb_prepare_unicast(skb, orig_node))
349 goto out;
350 break;
351 case BATADV_UNICAST_4ADDR:
352 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
353 orig_node,
354 packet_subtype))
355 goto out;
356 break;
357 default:
358 /* this function supports UNICAST and UNICAST_4ADDR only. It
359 * should never be invoked with any other packet type
360 */
361 goto out;
362 }
363
364 /* skb->data might have been reallocated by
365 * batadv_send_skb_prepare_unicast{,_4addr}()
366 */
367 ethhdr = eth_hdr(skb);
368 unicast_packet = (struct batadv_unicast_packet *)skb->data;
369
370 /* inform the destination node that we are still missing a correct route
371 * for this client. The destination will receive this packet and will
372 * try to reroute it because the ttvn contained in the header is less
373 * than the current one
374 */
375 if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
376 unicast_packet->ttvn = unicast_packet->ttvn - 1;
377
378 ret = batadv_send_skb_to_orig(skb, orig_node, NULL);
379 /* skb was consumed */
380 skb = NULL;
381
382out:
383 kfree_skb(skb);
384 return ret;
385}
386
387/**
388 * batadv_send_skb_via_tt_generic() - send an skb via TT lookup
389 * @bat_priv: the bat priv with all the soft interface information
390 * @skb: payload to send
391 * @packet_type: the batman unicast packet type to use
392 * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
393 * 4addr packets)
394 * @dst_hint: can be used to override the destination contained in the skb
395 * @vid: the vid to be used to search the translation table
396 *
397 * Look up the recipient node for the destination address in the ethernet
398 * header via the translation table. Wrap the given skb into a batman-adv
399 * unicast or unicast-4addr header depending on whether BATADV_UNICAST or
400 * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
401 * to the according destination node.
402 *
403 * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
404 */
405int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
406 struct sk_buff *skb, int packet_type,
407 int packet_subtype, u8 *dst_hint,
408 unsigned short vid)
409{
410 struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
411 struct batadv_orig_node *orig_node;
412 u8 *src, *dst;
413 int ret;
414
415 src = ethhdr->h_source;
416 dst = ethhdr->h_dest;
417
418 /* if we got an hint! let's send the packet to this client (if any) */
419 if (dst_hint) {
420 src = NULL;
421 dst = dst_hint;
422 }
423 orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
424
425 ret = batadv_send_skb_unicast(bat_priv, skb, packet_type,
426 packet_subtype, orig_node, vid);
427
428 if (orig_node)
429 batadv_orig_node_put(orig_node);
430
431 return ret;
432}
433
434/**
435 * batadv_send_skb_via_gw() - send an skb via gateway lookup
436 * @bat_priv: the bat priv with all the soft interface information
437 * @skb: payload to send
438 * @vid: the vid to be used to search the translation table
439 *
440 * Look up the currently selected gateway. Wrap the given skb into a batman-adv
441 * unicast header and send this frame to this gateway node.
442 *
443 * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
444 */
445int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
446 unsigned short vid)
447{
448 struct batadv_orig_node *orig_node;
449 int ret;
450
451 orig_node = batadv_gw_get_selected_orig(bat_priv);
452 ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR,
453 BATADV_P_DATA, orig_node, vid);
454
455 if (orig_node)
456 batadv_orig_node_put(orig_node);
457
458 return ret;
459}
460
461/**
462 * batadv_forw_packet_free() - free a forwarding packet
463 * @forw_packet: The packet to free
464 * @dropped: whether the packet is freed because is dropped
465 *
466 * This frees a forwarding packet and releases any resources it might
467 * have claimed.
468 */
469void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet,
470 bool dropped)
471{
472 if (dropped)
473 kfree_skb(forw_packet->skb);
474 else
475 consume_skb(forw_packet->skb);
476
477 if (forw_packet->if_incoming)
478 batadv_hardif_put(forw_packet->if_incoming);
479 if (forw_packet->if_outgoing)
480 batadv_hardif_put(forw_packet->if_outgoing);
481 if (forw_packet->queue_left)
482 atomic_inc(forw_packet->queue_left);
483 kfree(forw_packet);
484}
485
486/**
487 * batadv_forw_packet_alloc() - allocate a forwarding packet
488 * @if_incoming: The (optional) if_incoming to be grabbed
489 * @if_outgoing: The (optional) if_outgoing to be grabbed
490 * @queue_left: The (optional) queue counter to decrease
491 * @bat_priv: The bat_priv for the mesh of this forw_packet
492 * @skb: The raw packet this forwarding packet shall contain
493 *
494 * Allocates a forwarding packet and tries to get a reference to the
495 * (optional) if_incoming, if_outgoing and queue_left. If queue_left
496 * is NULL then bat_priv is optional, too.
497 *
498 * Return: An allocated forwarding packet on success, NULL otherwise.
499 */
500struct batadv_forw_packet *
501batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming,
502 struct batadv_hard_iface *if_outgoing,
503 atomic_t *queue_left,
504 struct batadv_priv *bat_priv,
505 struct sk_buff *skb)
506{
507 struct batadv_forw_packet *forw_packet;
508 const char *qname;
509
510 if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) {
511 qname = "unknown";
512
513 if (queue_left == &bat_priv->bcast_queue_left)
514 qname = "bcast";
515
516 if (queue_left == &bat_priv->batman_queue_left)
517 qname = "batman";
518
519 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
520 "%s queue is full\n", qname);
521
522 return NULL;
523 }
524
525 forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
526 if (!forw_packet)
527 goto err;
528
529 if (if_incoming)
530 kref_get(&if_incoming->refcount);
531
532 if (if_outgoing)
533 kref_get(&if_outgoing->refcount);
534
535 INIT_HLIST_NODE(&forw_packet->list);
536 INIT_HLIST_NODE(&forw_packet->cleanup_list);
537 forw_packet->skb = skb;
538 forw_packet->queue_left = queue_left;
539 forw_packet->if_incoming = if_incoming;
540 forw_packet->if_outgoing = if_outgoing;
541 forw_packet->num_packets = 0;
542
543 return forw_packet;
544
545err:
546 if (queue_left)
547 atomic_inc(queue_left);
548
549 return NULL;
550}
551
552/**
553 * batadv_forw_packet_was_stolen() - check whether someone stole this packet
554 * @forw_packet: the forwarding packet to check
555 *
556 * This function checks whether the given forwarding packet was claimed by
557 * someone else for free().
558 *
559 * Return: True if someone stole it, false otherwise.
560 */
561static bool
562batadv_forw_packet_was_stolen(struct batadv_forw_packet *forw_packet)
563{
564 return !hlist_unhashed(&forw_packet->cleanup_list);
565}
566
567/**
568 * batadv_forw_packet_steal() - claim a forw_packet for free()
569 * @forw_packet: the forwarding packet to steal
570 * @lock: a key to the store to steal from (e.g. forw_{bat,bcast}_list_lock)
571 *
572 * This function tries to steal a specific forw_packet from global
573 * visibility for the purpose of getting it for free(). That means
574 * the caller is *not* allowed to requeue it afterwards.
575 *
576 * Return: True if stealing was successful. False if someone else stole it
577 * before us.
578 */
579bool batadv_forw_packet_steal(struct batadv_forw_packet *forw_packet,
580 spinlock_t *lock)
581{
582 /* did purging routine steal it earlier? */
583 spin_lock_bh(lock);
584 if (batadv_forw_packet_was_stolen(forw_packet)) {
585 spin_unlock_bh(lock);
586 return false;
587 }
588
589 hlist_del_init(&forw_packet->list);
590
591 /* Just to spot misuse of this function */
592 hlist_add_fake(&forw_packet->cleanup_list);
593
594 spin_unlock_bh(lock);
595 return true;
596}
597
598/**
599 * batadv_forw_packet_list_steal() - claim a list of forward packets for free()
600 * @forw_list: the to be stolen forward packets
601 * @cleanup_list: a backup pointer, to be able to dispose the packet later
602 * @hard_iface: the interface to steal forward packets from
603 *
604 * This function claims responsibility to free any forw_packet queued on the
605 * given hard_iface. If hard_iface is NULL forwarding packets on all hard
606 * interfaces will be claimed.
607 *
608 * The packets are being moved from the forw_list to the cleanup_list. This
609 * makes it possible for already running threads to notice the claim.
610 */
611static void
612batadv_forw_packet_list_steal(struct hlist_head *forw_list,
613 struct hlist_head *cleanup_list,
614 const struct batadv_hard_iface *hard_iface)
615{
616 struct batadv_forw_packet *forw_packet;
617 struct hlist_node *safe_tmp_node;
618
619 hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
620 forw_list, list) {
621 /* if purge_outstanding_packets() was called with an argument
622 * we delete only packets belonging to the given interface
623 */
624 if (hard_iface &&
625 forw_packet->if_incoming != hard_iface &&
626 forw_packet->if_outgoing != hard_iface)
627 continue;
628
629 hlist_del(&forw_packet->list);
630 hlist_add_head(&forw_packet->cleanup_list, cleanup_list);
631 }
632}
633
634/**
635 * batadv_forw_packet_list_free() - free a list of forward packets
636 * @head: a list of to be freed forw_packets
637 *
638 * This function cancels the scheduling of any packet in the provided list,
639 * waits for any possibly running packet forwarding thread to finish and
640 * finally, safely frees this forward packet.
641 *
642 * This function might sleep.
643 */
644static void batadv_forw_packet_list_free(struct hlist_head *head)
645{
646 struct batadv_forw_packet *forw_packet;
647 struct hlist_node *safe_tmp_node;
648
649 hlist_for_each_entry_safe(forw_packet, safe_tmp_node, head,
650 cleanup_list) {
651 cancel_delayed_work_sync(&forw_packet->delayed_work);
652
653 hlist_del(&forw_packet->cleanup_list);
654 batadv_forw_packet_free(forw_packet, true);
655 }
656}
657
658/**
659 * batadv_forw_packet_queue() - try to queue a forwarding packet
660 * @forw_packet: the forwarding packet to queue
661 * @lock: a key to the store (e.g. forw_{bat,bcast}_list_lock)
662 * @head: the shelve to queue it on (e.g. forw_{bat,bcast}_list)
663 * @send_time: timestamp (jiffies) when the packet is to be sent
664 *
665 * This function tries to (re)queue a forwarding packet. Requeuing
666 * is prevented if the according interface is shutting down
667 * (e.g. if batadv_forw_packet_list_steal() was called for this
668 * packet earlier).
669 *
670 * Calling batadv_forw_packet_queue() after a call to
671 * batadv_forw_packet_steal() is forbidden!
672 *
673 * Caller needs to ensure that forw_packet->delayed_work was initialized.
674 */
675static void batadv_forw_packet_queue(struct batadv_forw_packet *forw_packet,
676 spinlock_t *lock, struct hlist_head *head,
677 unsigned long send_time)
678{
679 spin_lock_bh(lock);
680
681 /* did purging routine steal it from us? */
682 if (batadv_forw_packet_was_stolen(forw_packet)) {
683 /* If you got it for free() without trouble, then
684 * don't get back into the queue after stealing...
685 */
686 WARN_ONCE(hlist_fake(&forw_packet->cleanup_list),
687 "Requeuing after batadv_forw_packet_steal() not allowed!\n");
688
689 spin_unlock_bh(lock);
690 return;
691 }
692
693 hlist_del_init(&forw_packet->list);
694 hlist_add_head(&forw_packet->list, head);
695
696 queue_delayed_work(batadv_event_workqueue,
697 &forw_packet->delayed_work,
698 send_time - jiffies);
699 spin_unlock_bh(lock);
700}
701
702/**
703 * batadv_forw_packet_bcast_queue() - try to queue a broadcast packet
704 * @bat_priv: the bat priv with all the soft interface information
705 * @forw_packet: the forwarding packet to queue
706 * @send_time: timestamp (jiffies) when the packet is to be sent
707 *
708 * This function tries to (re)queue a broadcast packet.
709 *
710 * Caller needs to ensure that forw_packet->delayed_work was initialized.
711 */
712static void
713batadv_forw_packet_bcast_queue(struct batadv_priv *bat_priv,
714 struct batadv_forw_packet *forw_packet,
715 unsigned long send_time)
716{
717 batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bcast_list_lock,
718 &bat_priv->forw_bcast_list, send_time);
719}
720
721/**
722 * batadv_forw_packet_ogmv1_queue() - try to queue an OGMv1 packet
723 * @bat_priv: the bat priv with all the soft interface information
724 * @forw_packet: the forwarding packet to queue
725 * @send_time: timestamp (jiffies) when the packet is to be sent
726 *
727 * This function tries to (re)queue an OGMv1 packet.
728 *
729 * Caller needs to ensure that forw_packet->delayed_work was initialized.
730 */
731void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv,
732 struct batadv_forw_packet *forw_packet,
733 unsigned long send_time)
734{
735 batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bat_list_lock,
736 &bat_priv->forw_bat_list, send_time);
737}
738
739/**
740 * batadv_forw_bcast_packet_to_list() - queue broadcast packet for transmissions
741 * @bat_priv: the bat priv with all the soft interface information
742 * @skb: broadcast packet to add
743 * @delay: number of jiffies to wait before sending
744 * @own_packet: true if it is a self-generated broadcast packet
745 * @if_in: the interface where the packet was received on
746 * @if_out: the outgoing interface to queue on
747 *
748 * Adds a broadcast packet to the queue and sets up timers. Broadcast packets
749 * are sent multiple times to increase probability for being received.
750 *
751 * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
752 */
753static int batadv_forw_bcast_packet_to_list(struct batadv_priv *bat_priv,
754 struct sk_buff *skb,
755 unsigned long delay,
756 bool own_packet,
757 struct batadv_hard_iface *if_in,
758 struct batadv_hard_iface *if_out)
759{
760 struct batadv_forw_packet *forw_packet;
761 unsigned long send_time = jiffies;
762 struct sk_buff *newskb;
763
764 newskb = skb_copy(skb, GFP_ATOMIC);
765 if (!newskb)
766 goto err;
767
768 forw_packet = batadv_forw_packet_alloc(if_in, if_out,
769 &bat_priv->bcast_queue_left,
770 bat_priv, newskb);
771 if (!forw_packet)
772 goto err_packet_free;
773
774 forw_packet->own = own_packet;
775
776 INIT_DELAYED_WORK(&forw_packet->delayed_work,
777 batadv_send_outstanding_bcast_packet);
778
779 send_time += delay ? delay : msecs_to_jiffies(5);
780
781 batadv_forw_packet_bcast_queue(bat_priv, forw_packet, send_time);
782 return NETDEV_TX_OK;
783
784err_packet_free:
785 kfree_skb(newskb);
786err:
787 return NETDEV_TX_BUSY;
788}
789
790/**
791 * batadv_forw_bcast_packet_if() - forward and queue a broadcast packet
792 * @bat_priv: the bat priv with all the soft interface information
793 * @skb: broadcast packet to add
794 * @delay: number of jiffies to wait before sending
795 * @own_packet: true if it is a self-generated broadcast packet
796 * @if_in: the interface where the packet was received on
797 * @if_out: the outgoing interface to forward to
798 *
799 * Transmits a broadcast packet on the specified interface either immediately
800 * or if a delay is given after that. Furthermore, queues additional
801 * retransmissions if this interface is a wireless one.
802 *
803 * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
804 */
805static int batadv_forw_bcast_packet_if(struct batadv_priv *bat_priv,
806 struct sk_buff *skb,
807 unsigned long delay,
808 bool own_packet,
809 struct batadv_hard_iface *if_in,
810 struct batadv_hard_iface *if_out)
811{
812 unsigned int num_bcasts = if_out->num_bcasts;
813 struct sk_buff *newskb;
814 int ret = NETDEV_TX_OK;
815
816 if (!delay) {
817 newskb = skb_copy(skb, GFP_ATOMIC);
818 if (!newskb)
819 return NETDEV_TX_BUSY;
820
821 batadv_send_broadcast_skb(newskb, if_out);
822 num_bcasts--;
823 }
824
825 /* delayed broadcast or rebroadcasts? */
826 if (num_bcasts >= 1) {
827 BATADV_SKB_CB(skb)->num_bcasts = num_bcasts;
828
829 ret = batadv_forw_bcast_packet_to_list(bat_priv, skb, delay,
830 own_packet, if_in,
831 if_out);
832 }
833
834 return ret;
835}
836
837/**
838 * batadv_send_no_broadcast() - check whether (re)broadcast is necessary
839 * @bat_priv: the bat priv with all the soft interface information
840 * @skb: broadcast packet to check
841 * @own_packet: true if it is a self-generated broadcast packet
842 * @if_out: the outgoing interface checked and considered for (re)broadcast
843 *
844 * Return: False if a packet needs to be (re)broadcasted on the given interface,
845 * true otherwise.
846 */
847static bool batadv_send_no_broadcast(struct batadv_priv *bat_priv,
848 struct sk_buff *skb, bool own_packet,
849 struct batadv_hard_iface *if_out)
850{
851 struct batadv_hardif_neigh_node *neigh_node = NULL;
852 struct batadv_bcast_packet *bcast_packet;
853 u8 *orig_neigh;
854 u8 *neigh_addr;
855 char *type;
856 int ret;
857
858 if (!own_packet) {
859 neigh_addr = eth_hdr(skb)->h_source;
860 neigh_node = batadv_hardif_neigh_get(if_out,
861 neigh_addr);
862 }
863
864 bcast_packet = (struct batadv_bcast_packet *)skb->data;
865 orig_neigh = neigh_node ? neigh_node->orig : NULL;
866
867 ret = batadv_hardif_no_broadcast(if_out, bcast_packet->orig,
868 orig_neigh);
869
870 if (neigh_node)
871 batadv_hardif_neigh_put(neigh_node);
872
873 /* ok, may broadcast */
874 if (!ret)
875 return false;
876
877 /* no broadcast */
878 switch (ret) {
879 case BATADV_HARDIF_BCAST_NORECIPIENT:
880 type = "no neighbor";
881 break;
882 case BATADV_HARDIF_BCAST_DUPFWD:
883 type = "single neighbor is source";
884 break;
885 case BATADV_HARDIF_BCAST_DUPORIG:
886 type = "single neighbor is originator";
887 break;
888 default:
889 type = "unknown";
890 }
891
892 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
893 "BCAST packet from orig %pM on %s suppressed: %s\n",
894 bcast_packet->orig,
895 if_out->net_dev->name, type);
896
897 return true;
898}
899
900/**
901 * __batadv_forw_bcast_packet() - forward and queue a broadcast packet
902 * @bat_priv: the bat priv with all the soft interface information
903 * @skb: broadcast packet to add
904 * @delay: number of jiffies to wait before sending
905 * @own_packet: true if it is a self-generated broadcast packet
906 *
907 * Transmits a broadcast packet either immediately or if a delay is given
908 * after that. Furthermore, queues additional retransmissions on wireless
909 * interfaces.
910 *
911 * This call clones the given skb, hence the caller needs to take into
912 * account that the data segment of the given skb might not be
913 * modifiable anymore.
914 *
915 * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
916 */
917static int __batadv_forw_bcast_packet(struct batadv_priv *bat_priv,
918 struct sk_buff *skb,
919 unsigned long delay,
920 bool own_packet)
921{
922 struct batadv_hard_iface *hard_iface;
923 struct batadv_hard_iface *primary_if;
924 int ret = NETDEV_TX_OK;
925
926 primary_if = batadv_primary_if_get_selected(bat_priv);
927 if (!primary_if)
928 return NETDEV_TX_BUSY;
929
930 rcu_read_lock();
931 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
932 if (hard_iface->soft_iface != bat_priv->soft_iface)
933 continue;
934
935 if (!kref_get_unless_zero(&hard_iface->refcount))
936 continue;
937
938 if (batadv_send_no_broadcast(bat_priv, skb, own_packet,
939 hard_iface)) {
940 batadv_hardif_put(hard_iface);
941 continue;
942 }
943
944 ret = batadv_forw_bcast_packet_if(bat_priv, skb, delay,
945 own_packet, primary_if,
946 hard_iface);
947 batadv_hardif_put(hard_iface);
948
949 if (ret == NETDEV_TX_BUSY)
950 break;
951 }
952 rcu_read_unlock();
953
954 batadv_hardif_put(primary_if);
955 return ret;
956}
957
958/**
959 * batadv_forw_bcast_packet() - forward and queue a broadcast packet
960 * @bat_priv: the bat priv with all the soft interface information
961 * @skb: broadcast packet to add
962 * @delay: number of jiffies to wait before sending
963 * @own_packet: true if it is a self-generated broadcast packet
964 *
965 * Transmits a broadcast packet either immediately or if a delay is given
966 * after that. Furthermore, queues additional retransmissions on wireless
967 * interfaces.
968 *
969 * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
970 */
971int batadv_forw_bcast_packet(struct batadv_priv *bat_priv,
972 struct sk_buff *skb,
973 unsigned long delay,
974 bool own_packet)
975{
976 return __batadv_forw_bcast_packet(bat_priv, skb, delay, own_packet);
977}
978
979/**
980 * batadv_send_bcast_packet() - send and queue a broadcast packet
981 * @bat_priv: the bat priv with all the soft interface information
982 * @skb: broadcast packet to add
983 * @delay: number of jiffies to wait before sending
984 * @own_packet: true if it is a self-generated broadcast packet
985 *
986 * Transmits a broadcast packet either immediately or if a delay is given
987 * after that. Furthermore, queues additional retransmissions on wireless
988 * interfaces.
989 *
990 * Consumes the provided skb.
991 */
992void batadv_send_bcast_packet(struct batadv_priv *bat_priv,
993 struct sk_buff *skb,
994 unsigned long delay,
995 bool own_packet)
996{
997 __batadv_forw_bcast_packet(bat_priv, skb, delay, own_packet);
998 consume_skb(skb);
999}
1000
1001/**
1002 * batadv_forw_packet_bcasts_left() - check if a retransmission is necessary
1003 * @forw_packet: the forwarding packet to check
1004 *
1005 * Checks whether a given packet has any (re)transmissions left on the provided
1006 * interface.
1007 *
1008 * hard_iface may be NULL: In that case the number of transmissions this skb had
1009 * so far is compared with the maximum amount of retransmissions independent of
1010 * any interface instead.
1011 *
1012 * Return: True if (re)transmissions are left, false otherwise.
1013 */
1014static bool
1015batadv_forw_packet_bcasts_left(struct batadv_forw_packet *forw_packet)
1016{
1017 return BATADV_SKB_CB(forw_packet->skb)->num_bcasts;
1018}
1019
1020/**
1021 * batadv_forw_packet_bcasts_dec() - decrement retransmission counter of a
1022 * packet
1023 * @forw_packet: the packet to decrease the counter for
1024 */
1025static void
1026batadv_forw_packet_bcasts_dec(struct batadv_forw_packet *forw_packet)
1027{
1028 BATADV_SKB_CB(forw_packet->skb)->num_bcasts--;
1029}
1030
1031/**
1032 * batadv_forw_packet_is_rebroadcast() - check packet for previous transmissions
1033 * @forw_packet: the packet to check
1034 *
1035 * Return: True if this packet was transmitted before, false otherwise.
1036 */
1037bool batadv_forw_packet_is_rebroadcast(struct batadv_forw_packet *forw_packet)
1038{
1039 unsigned char num_bcasts = BATADV_SKB_CB(forw_packet->skb)->num_bcasts;
1040
1041 return num_bcasts != forw_packet->if_outgoing->num_bcasts;
1042}
1043
1044/**
1045 * batadv_send_outstanding_bcast_packet() - transmit a queued broadcast packet
1046 * @work: work queue item
1047 *
1048 * Transmits a queued broadcast packet and if necessary reschedules it.
1049 */
1050static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
1051{
1052 unsigned long send_time = jiffies + msecs_to_jiffies(5);
1053 struct batadv_forw_packet *forw_packet;
1054 struct delayed_work *delayed_work;
1055 struct batadv_priv *bat_priv;
1056 struct sk_buff *skb1;
1057 bool dropped = false;
1058
1059 delayed_work = to_delayed_work(work);
1060 forw_packet = container_of(delayed_work, struct batadv_forw_packet,
1061 delayed_work);
1062 bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
1063
1064 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
1065 dropped = true;
1066 goto out;
1067 }
1068
1069 if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) {
1070 dropped = true;
1071 goto out;
1072 }
1073
1074 /* send a copy of the saved skb */
1075 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
1076 if (!skb1)
1077 goto out;
1078
1079 batadv_send_broadcast_skb(skb1, forw_packet->if_outgoing);
1080 batadv_forw_packet_bcasts_dec(forw_packet);
1081
1082 if (batadv_forw_packet_bcasts_left(forw_packet)) {
1083 batadv_forw_packet_bcast_queue(bat_priv, forw_packet,
1084 send_time);
1085 return;
1086 }
1087
1088out:
1089 /* do we get something for free()? */
1090 if (batadv_forw_packet_steal(forw_packet,
1091 &bat_priv->forw_bcast_list_lock))
1092 batadv_forw_packet_free(forw_packet, dropped);
1093}
1094
1095/**
1096 * batadv_purge_outstanding_packets() - stop/purge scheduled bcast/OGMv1 packets
1097 * @bat_priv: the bat priv with all the soft interface information
1098 * @hard_iface: the hard interface to cancel and purge bcast/ogm packets on
1099 *
1100 * This method cancels and purges any broadcast and OGMv1 packet on the given
1101 * hard_iface. If hard_iface is NULL, broadcast and OGMv1 packets on all hard
1102 * interfaces will be canceled and purged.
1103 *
1104 * This function might sleep.
1105 */
1106void
1107batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
1108 const struct batadv_hard_iface *hard_iface)
1109{
1110 struct hlist_head head = HLIST_HEAD_INIT;
1111
1112 if (hard_iface)
1113 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1114 "%s(): %s\n",
1115 __func__, hard_iface->net_dev->name);
1116 else
1117 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1118 "%s()\n", __func__);
1119
1120 /* claim bcast list for free() */
1121 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
1122 batadv_forw_packet_list_steal(&bat_priv->forw_bcast_list, &head,
1123 hard_iface);
1124 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
1125
1126 /* claim batman packet list for free() */
1127 spin_lock_bh(&bat_priv->forw_bat_list_lock);
1128 batadv_forw_packet_list_steal(&bat_priv->forw_bat_list, &head,
1129 hard_iface);
1130 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
1131
1132 /* then cancel or wait for packet workers to finish and free */
1133 batadv_forw_packet_list_free(&head);
1134}