1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2007-2019 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
43 static 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 */
63 int 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);
110 send_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 */
124 int 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 */
139 int 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 */
177 int 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
217 put_neigh_node:
218 batadv_neigh_node_put(neigh_node);
219 free_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 */
234 static bool
235 batadv_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 */
265 static 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 */
283 bool 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;
311 out:
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 */
333 int 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
382 out:
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 */
405 int 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 */
445 int 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 is dropped
465 *
466 * This frees a forwarding packet and releases any resources it might
467 * have claimed.
468 */
469 void 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 */
500 struct batadv_forw_packet *
501 batadv_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
545 err:
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 */
561 static bool
562 batadv_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 */
579 bool 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 and
609 * by that allows already running threads to notice the claiming.
610 */
611 static void
612 batadv_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 */
644 static 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 */
675 static 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 */
712 static void
713 batadv_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 */
731 void 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_add_bcast_packet_to_list() - queue broadcast packet for multiple sends
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 *
746 * add a broadcast packet to the queue and setup timers. broadcast packets
747 * are sent multiple times to increase probability for being received.
748 *
749 * The skb is not consumed, so the caller should make sure that the
750 * skb is freed.
751 *
752 * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
753 */
754 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
755 const struct sk_buff *skb,
756 unsigned long delay,
757 bool own_packet)
758 {
759 struct batadv_hard_iface *primary_if;
760 struct batadv_forw_packet *forw_packet;
761 struct batadv_bcast_packet *bcast_packet;
762 struct sk_buff *newskb;
763
764 primary_if = batadv_primary_if_get_selected(bat_priv);
765 if (!primary_if)
766 goto err;
767
768 newskb = skb_copy(skb, GFP_ATOMIC);
769 if (!newskb) {
770 batadv_hardif_put(primary_if);
771 goto err;
772 }
773
774 forw_packet = batadv_forw_packet_alloc(primary_if, NULL,
775 &bat_priv->bcast_queue_left,
776 bat_priv, newskb);
777 batadv_hardif_put(primary_if);
778 if (!forw_packet)
779 goto err_packet_free;
780
781 /* as we have a copy now, it is safe to decrease the TTL */
782 bcast_packet = (struct batadv_bcast_packet *)newskb->data;
783 bcast_packet->ttl--;
784
785 forw_packet->own = own_packet;
786
787 INIT_DELAYED_WORK(&forw_packet->delayed_work,
788 batadv_send_outstanding_bcast_packet);
789
790 batadv_forw_packet_bcast_queue(bat_priv, forw_packet, jiffies + delay);
791 return NETDEV_TX_OK;
792
793 err_packet_free:
794 kfree_skb(newskb);
795 err:
796 return NETDEV_TX_BUSY;
797 }
798
799 /**
800 * batadv_forw_packet_bcasts_left() - check if a retransmission is necessary
801 * @forw_packet: the forwarding packet to check
802 * @hard_iface: the interface to check on
803 *
804 * Checks whether a given packet has any (re)transmissions left on the provided
805 * interface.
806 *
807 * hard_iface may be NULL: In that case the number of transmissions this skb had
808 * so far is compared with the maximum amount of retransmissions independent of
809 * any interface instead.
810 *
811 * Return: True if (re)transmissions are left, false otherwise.
812 */
813 static bool
814 batadv_forw_packet_bcasts_left(struct batadv_forw_packet *forw_packet,
815 struct batadv_hard_iface *hard_iface)
816 {
817 unsigned int max;
818
819 if (hard_iface)
820 max = hard_iface->num_bcasts;
821 else
822 max = BATADV_NUM_BCASTS_MAX;
823
824 return BATADV_SKB_CB(forw_packet->skb)->num_bcasts < max;
825 }
826
827 /**
828 * batadv_forw_packet_bcasts_inc() - increment retransmission counter of a
829 * packet
830 * @forw_packet: the packet to increase the counter for
831 */
832 static void
833 batadv_forw_packet_bcasts_inc(struct batadv_forw_packet *forw_packet)
834 {
835 BATADV_SKB_CB(forw_packet->skb)->num_bcasts++;
836 }
837
838 /**
839 * batadv_forw_packet_is_rebroadcast() - check packet for previous transmissions
840 * @forw_packet: the packet to check
841 *
842 * Return: True if this packet was transmitted before, false otherwise.
843 */
844 bool batadv_forw_packet_is_rebroadcast(struct batadv_forw_packet *forw_packet)
845 {
846 return BATADV_SKB_CB(forw_packet->skb)->num_bcasts > 0;
847 }
848
849 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
850 {
851 struct batadv_hard_iface *hard_iface;
852 struct batadv_hardif_neigh_node *neigh_node;
853 struct delayed_work *delayed_work;
854 struct batadv_forw_packet *forw_packet;
855 struct batadv_bcast_packet *bcast_packet;
856 struct sk_buff *skb1;
857 struct net_device *soft_iface;
858 struct batadv_priv *bat_priv;
859 unsigned long send_time = jiffies + msecs_to_jiffies(5);
860 bool dropped = false;
861 u8 *neigh_addr;
862 u8 *orig_neigh;
863 int ret = 0;
864
865 delayed_work = to_delayed_work(work);
866 forw_packet = container_of(delayed_work, struct batadv_forw_packet,
867 delayed_work);
868 soft_iface = forw_packet->if_incoming->soft_iface;
869 bat_priv = netdev_priv(soft_iface);
870
871 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
872 dropped = true;
873 goto out;
874 }
875
876 if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) {
877 dropped = true;
878 goto out;
879 }
880
881 bcast_packet = (struct batadv_bcast_packet *)forw_packet->skb->data;
882
883 /* rebroadcast packet */
884 rcu_read_lock();
885 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
886 if (hard_iface->soft_iface != soft_iface)
887 continue;
888
889 if (!batadv_forw_packet_bcasts_left(forw_packet, hard_iface))
890 continue;
891
892 if (forw_packet->own) {
893 neigh_node = NULL;
894 } else {
895 neigh_addr = eth_hdr(forw_packet->skb)->h_source;
896 neigh_node = batadv_hardif_neigh_get(hard_iface,
897 neigh_addr);
898 }
899
900 orig_neigh = neigh_node ? neigh_node->orig : NULL;
901
902 ret = batadv_hardif_no_broadcast(hard_iface, bcast_packet->orig,
903 orig_neigh);
904
905 if (ret) {
906 char *type;
907
908 switch (ret) {
909 case BATADV_HARDIF_BCAST_NORECIPIENT:
910 type = "no neighbor";
911 break;
912 case BATADV_HARDIF_BCAST_DUPFWD:
913 type = "single neighbor is source";
914 break;
915 case BATADV_HARDIF_BCAST_DUPORIG:
916 type = "single neighbor is originator";
917 break;
918 default:
919 type = "unknown";
920 }
921
922 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "BCAST packet from orig %pM on %s suppressed: %s\n",
923 bcast_packet->orig,
924 hard_iface->net_dev->name, type);
925
926 if (neigh_node)
927 batadv_hardif_neigh_put(neigh_node);
928
929 continue;
930 }
931
932 if (neigh_node)
933 batadv_hardif_neigh_put(neigh_node);
934
935 if (!kref_get_unless_zero(&hard_iface->refcount))
936 continue;
937
938 /* send a copy of the saved skb */
939 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
940 if (skb1)
941 batadv_send_broadcast_skb(skb1, hard_iface);
942
943 batadv_hardif_put(hard_iface);
944 }
945 rcu_read_unlock();
946
947 batadv_forw_packet_bcasts_inc(forw_packet);
948
949 /* if we still have some more bcasts to send */
950 if (batadv_forw_packet_bcasts_left(forw_packet, NULL)) {
951 batadv_forw_packet_bcast_queue(bat_priv, forw_packet,
952 send_time);
953 return;
954 }
955
956 out:
957 /* do we get something for free()? */
958 if (batadv_forw_packet_steal(forw_packet,
959 &bat_priv->forw_bcast_list_lock))
960 batadv_forw_packet_free(forw_packet, dropped);
961 }
962
963 /**
964 * batadv_purge_outstanding_packets() - stop/purge scheduled bcast/OGMv1 packets
965 * @bat_priv: the bat priv with all the soft interface information
966 * @hard_iface: the hard interface to cancel and purge bcast/ogm packets on
967 *
968 * This method cancels and purges any broadcast and OGMv1 packet on the given
969 * hard_iface. If hard_iface is NULL, broadcast and OGMv1 packets on all hard
970 * interfaces will be canceled and purged.
971 *
972 * This function might sleep.
973 */
974 void
975 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
976 const struct batadv_hard_iface *hard_iface)
977 {
978 struct hlist_head head = HLIST_HEAD_INIT;
979
980 if (hard_iface)
981 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
982 "%s(): %s\n",
983 __func__, hard_iface->net_dev->name);
984 else
985 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
986 "%s()\n", __func__);
987
988 /* claim bcast list for free() */
989 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
990 batadv_forw_packet_list_steal(&bat_priv->forw_bcast_list, &head,
991 hard_iface);
992 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
993
994 /* claim batman packet list for free() */
995 spin_lock_bh(&bat_priv->forw_bat_list_lock);
996 batadv_forw_packet_list_steal(&bat_priv->forw_bat_list, &head,
997 hard_iface);
998 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
999
1000 /* then cancel or wait for packet workers to finish and free */
1001 batadv_forw_packet_list_free(&head);
1002 }