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/container_of.h>
14 #include <linux/errno.h>
15 #include <linux/etherdevice.h>
16 #include <linux/gfp.h>
17 #include <linux/if.h>
18 #include <linux/if_ether.h>
19 #include <linux/jiffies.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 batadv_hardif_neigh_put(hardif_neigh);
156 #endif
157
158 return ret;
159 }
160
161 /**
162 * batadv_send_skb_to_orig() - Lookup next-hop and transmit skb.
163 * @skb: Packet to be transmitted.
164 * @orig_node: Final destination of the packet.
165 * @recv_if: Interface used when receiving the packet (can be NULL).
166 *
167 * Looks up the best next-hop towards the passed originator and passes the
168 * skb on for preparation of MAC header. If the packet originated from this
169 * host, NULL can be passed as recv_if and no interface alternating is
170 * attempted.
171 *
172 * Return: negative errno code on a failure, -EINPROGRESS if the skb is
173 * buffered for later transmit or the NET_XMIT status returned by the
174 * lower routine if the packet has been passed down.
175 */
176 int batadv_send_skb_to_orig(struct sk_buff *skb,
177 struct batadv_orig_node *orig_node,
178 struct batadv_hard_iface *recv_if)
179 {
180 struct batadv_priv *bat_priv = orig_node->bat_priv;
181 struct batadv_neigh_node *neigh_node;
182 int ret;
183
184 /* batadv_find_router() increases neigh_nodes refcount if found. */
185 neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
186 if (!neigh_node) {
187 ret = -EINVAL;
188 goto free_skb;
189 }
190
191 /* Check if the skb is too large to send in one piece and fragment
192 * it if needed.
193 */
194 if (atomic_read(&bat_priv->fragmentation) &&
195 skb->len > neigh_node->if_incoming->net_dev->mtu) {
196 /* Fragment and send packet. */
197 ret = batadv_frag_send_packet(skb, orig_node, neigh_node);
198 /* skb was consumed */
199 skb = NULL;
200
201 goto put_neigh_node;
202 }
203
204 /* try to network code the packet, if it is received on an interface
205 * (i.e. being forwarded). If the packet originates from this node or if
206 * network coding fails, then send the packet as usual.
207 */
208 if (recv_if && batadv_nc_skb_forward(skb, neigh_node))
209 ret = -EINPROGRESS;
210 else
211 ret = batadv_send_unicast_skb(skb, neigh_node);
212
213 /* skb was consumed */
214 skb = NULL;
215
216 put_neigh_node:
217 batadv_neigh_node_put(neigh_node);
218 free_skb:
219 kfree_skb(skb);
220
221 return ret;
222 }
223
224 /**
225 * batadv_send_skb_push_fill_unicast() - extend the buffer and initialize the
226 * common fields for unicast packets
227 * @skb: the skb carrying the unicast header to initialize
228 * @hdr_size: amount of bytes to push at the beginning of the skb
229 * @orig_node: the destination node
230 *
231 * Return: false if the buffer extension was not possible or true otherwise.
232 */
233 static bool
234 batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
235 struct batadv_orig_node *orig_node)
236 {
237 struct batadv_unicast_packet *unicast_packet;
238 u8 ttvn = (u8)atomic_read(&orig_node->last_ttvn);
239
240 if (batadv_skb_head_push(skb, hdr_size) < 0)
241 return false;
242
243 unicast_packet = (struct batadv_unicast_packet *)skb->data;
244 unicast_packet->version = BATADV_COMPAT_VERSION;
245 /* batman packet type: unicast */
246 unicast_packet->packet_type = BATADV_UNICAST;
247 /* set unicast ttl */
248 unicast_packet->ttl = BATADV_TTL;
249 /* copy the destination for faster routing */
250 ether_addr_copy(unicast_packet->dest, orig_node->orig);
251 /* set the destination tt version number */
252 unicast_packet->ttvn = ttvn;
253
254 return true;
255 }
256
257 /**
258 * batadv_send_skb_prepare_unicast() - encapsulate an skb with a unicast header
259 * @skb: the skb containing the payload to encapsulate
260 * @orig_node: the destination node
261 *
262 * Return: false if the payload could not be encapsulated or true otherwise.
263 */
264 static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
265 struct batadv_orig_node *orig_node)
266 {
267 size_t uni_size = sizeof(struct batadv_unicast_packet);
268
269 return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
270 }
271
272 /**
273 * batadv_send_skb_prepare_unicast_4addr() - encapsulate an skb with a
274 * unicast 4addr header
275 * @bat_priv: the bat priv with all the soft interface information
276 * @skb: the skb containing the payload to encapsulate
277 * @orig: the destination node
278 * @packet_subtype: the unicast 4addr packet subtype to use
279 *
280 * Return: false if the payload could not be encapsulated or true otherwise.
281 */
282 bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
283 struct sk_buff *skb,
284 struct batadv_orig_node *orig,
285 int packet_subtype)
286 {
287 struct batadv_hard_iface *primary_if;
288 struct batadv_unicast_4addr_packet *uc_4addr_packet;
289 bool ret = false;
290
291 primary_if = batadv_primary_if_get_selected(bat_priv);
292 if (!primary_if)
293 goto out;
294
295 /* Pull the header space and fill the unicast_packet substructure.
296 * We can do that because the first member of the uc_4addr_packet
297 * is of type struct unicast_packet
298 */
299 if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
300 orig))
301 goto out;
302
303 uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
304 uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
305 ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr);
306 uc_4addr_packet->subtype = packet_subtype;
307 uc_4addr_packet->reserved = 0;
308
309 ret = true;
310 out:
311 batadv_hardif_put(primary_if);
312 return ret;
313 }
314
315 /**
316 * batadv_send_skb_unicast() - encapsulate and send an skb via unicast
317 * @bat_priv: the bat priv with all the soft interface information
318 * @skb: payload to send
319 * @packet_type: the batman unicast packet type to use
320 * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
321 * 4addr packets)
322 * @orig_node: the originator to send the packet to
323 * @vid: the vid to be used to search the translation table
324 *
325 * Wrap the given skb into a batman-adv unicast or unicast-4addr header
326 * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
327 * as packet_type. Then send this frame to the given orig_node.
328 *
329 * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
330 */
331 int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
332 struct sk_buff *skb, int packet_type,
333 int packet_subtype,
334 struct batadv_orig_node *orig_node,
335 unsigned short vid)
336 {
337 struct batadv_unicast_packet *unicast_packet;
338 struct ethhdr *ethhdr;
339 int ret = NET_XMIT_DROP;
340
341 if (!orig_node)
342 goto out;
343
344 switch (packet_type) {
345 case BATADV_UNICAST:
346 if (!batadv_send_skb_prepare_unicast(skb, orig_node))
347 goto out;
348 break;
349 case BATADV_UNICAST_4ADDR:
350 if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
351 orig_node,
352 packet_subtype))
353 goto out;
354 break;
355 default:
356 /* this function supports UNICAST and UNICAST_4ADDR only. It
357 * should never be invoked with any other packet type
358 */
359 goto out;
360 }
361
362 /* skb->data might have been reallocated by
363 * batadv_send_skb_prepare_unicast{,_4addr}()
364 */
365 ethhdr = eth_hdr(skb);
366 unicast_packet = (struct batadv_unicast_packet *)skb->data;
367
368 /* inform the destination node that we are still missing a correct route
369 * for this client. The destination will receive this packet and will
370 * try to reroute it because the ttvn contained in the header is less
371 * than the current one
372 */
373 if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
374 unicast_packet->ttvn = unicast_packet->ttvn - 1;
375
376 ret = batadv_send_skb_to_orig(skb, orig_node, NULL);
377 /* skb was consumed */
378 skb = NULL;
379
380 out:
381 kfree_skb(skb);
382 return ret;
383 }
384
385 /**
386 * batadv_send_skb_via_tt_generic() - send an skb via TT lookup
387 * @bat_priv: the bat priv with all the soft interface information
388 * @skb: payload to send
389 * @packet_type: the batman unicast packet type to use
390 * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
391 * 4addr packets)
392 * @dst_hint: can be used to override the destination contained in the skb
393 * @vid: the vid to be used to search the translation table
394 *
395 * Look up the recipient node for the destination address in the ethernet
396 * header via the translation table. Wrap the given skb into a batman-adv
397 * unicast or unicast-4addr header depending on whether BATADV_UNICAST or
398 * BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
399 * to the according destination node.
400 *
401 * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
402 */
403 int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
404 struct sk_buff *skb, int packet_type,
405 int packet_subtype, u8 *dst_hint,
406 unsigned short vid)
407 {
408 struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
409 struct batadv_orig_node *orig_node;
410 u8 *src, *dst;
411 int ret;
412
413 src = ethhdr->h_source;
414 dst = ethhdr->h_dest;
415
416 /* if we got an hint! let's send the packet to this client (if any) */
417 if (dst_hint) {
418 src = NULL;
419 dst = dst_hint;
420 }
421 orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
422
423 ret = batadv_send_skb_unicast(bat_priv, skb, packet_type,
424 packet_subtype, orig_node, vid);
425
426 batadv_orig_node_put(orig_node);
427
428 return ret;
429 }
430
431 /**
432 * batadv_send_skb_via_gw() - send an skb via gateway lookup
433 * @bat_priv: the bat priv with all the soft interface information
434 * @skb: payload to send
435 * @vid: the vid to be used to search the translation table
436 *
437 * Look up the currently selected gateway. Wrap the given skb into a batman-adv
438 * unicast header and send this frame to this gateway node.
439 *
440 * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
441 */
442 int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
443 unsigned short vid)
444 {
445 struct batadv_orig_node *orig_node;
446 int ret;
447
448 orig_node = batadv_gw_get_selected_orig(bat_priv);
449 ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR,
450 BATADV_P_DATA, orig_node, vid);
451
452 batadv_orig_node_put(orig_node);
453
454 return ret;
455 }
456
457 /**
458 * batadv_forw_packet_free() - free a forwarding packet
459 * @forw_packet: The packet to free
460 * @dropped: whether the packet is freed because is dropped
461 *
462 * This frees a forwarding packet and releases any resources it might
463 * have claimed.
464 */
465 void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet,
466 bool dropped)
467 {
468 if (dropped)
469 kfree_skb(forw_packet->skb);
470 else
471 consume_skb(forw_packet->skb);
472
473 batadv_hardif_put(forw_packet->if_incoming);
474 batadv_hardif_put(forw_packet->if_outgoing);
475 if (forw_packet->queue_left)
476 atomic_inc(forw_packet->queue_left);
477 kfree(forw_packet);
478 }
479
480 /**
481 * batadv_forw_packet_alloc() - allocate a forwarding packet
482 * @if_incoming: The (optional) if_incoming to be grabbed
483 * @if_outgoing: The (optional) if_outgoing to be grabbed
484 * @queue_left: The (optional) queue counter to decrease
485 * @bat_priv: The bat_priv for the mesh of this forw_packet
486 * @skb: The raw packet this forwarding packet shall contain
487 *
488 * Allocates a forwarding packet and tries to get a reference to the
489 * (optional) if_incoming, if_outgoing and queue_left. If queue_left
490 * is NULL then bat_priv is optional, too.
491 *
492 * Return: An allocated forwarding packet on success, NULL otherwise.
493 */
494 struct batadv_forw_packet *
495 batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming,
496 struct batadv_hard_iface *if_outgoing,
497 atomic_t *queue_left,
498 struct batadv_priv *bat_priv,
499 struct sk_buff *skb)
500 {
501 struct batadv_forw_packet *forw_packet;
502 const char *qname;
503
504 if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) {
505 qname = "unknown";
506
507 if (queue_left == &bat_priv->bcast_queue_left)
508 qname = "bcast";
509
510 if (queue_left == &bat_priv->batman_queue_left)
511 qname = "batman";
512
513 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
514 "%s queue is full\n", qname);
515
516 return NULL;
517 }
518
519 forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
520 if (!forw_packet)
521 goto err;
522
523 if (if_incoming)
524 kref_get(&if_incoming->refcount);
525
526 if (if_outgoing)
527 kref_get(&if_outgoing->refcount);
528
529 INIT_HLIST_NODE(&forw_packet->list);
530 INIT_HLIST_NODE(&forw_packet->cleanup_list);
531 forw_packet->skb = skb;
532 forw_packet->queue_left = queue_left;
533 forw_packet->if_incoming = if_incoming;
534 forw_packet->if_outgoing = if_outgoing;
535 forw_packet->num_packets = 0;
536
537 return forw_packet;
538
539 err:
540 if (queue_left)
541 atomic_inc(queue_left);
542
543 return NULL;
544 }
545
546 /**
547 * batadv_forw_packet_was_stolen() - check whether someone stole this packet
548 * @forw_packet: the forwarding packet to check
549 *
550 * This function checks whether the given forwarding packet was claimed by
551 * someone else for free().
552 *
553 * Return: True if someone stole it, false otherwise.
554 */
555 static bool
556 batadv_forw_packet_was_stolen(struct batadv_forw_packet *forw_packet)
557 {
558 return !hlist_unhashed(&forw_packet->cleanup_list);
559 }
560
561 /**
562 * batadv_forw_packet_steal() - claim a forw_packet for free()
563 * @forw_packet: the forwarding packet to steal
564 * @lock: a key to the store to steal from (e.g. forw_{bat,bcast}_list_lock)
565 *
566 * This function tries to steal a specific forw_packet from global
567 * visibility for the purpose of getting it for free(). That means
568 * the caller is *not* allowed to requeue it afterwards.
569 *
570 * Return: True if stealing was successful. False if someone else stole it
571 * before us.
572 */
573 bool batadv_forw_packet_steal(struct batadv_forw_packet *forw_packet,
574 spinlock_t *lock)
575 {
576 /* did purging routine steal it earlier? */
577 spin_lock_bh(lock);
578 if (batadv_forw_packet_was_stolen(forw_packet)) {
579 spin_unlock_bh(lock);
580 return false;
581 }
582
583 hlist_del_init(&forw_packet->list);
584
585 /* Just to spot misuse of this function */
586 hlist_add_fake(&forw_packet->cleanup_list);
587
588 spin_unlock_bh(lock);
589 return true;
590 }
591
592 /**
593 * batadv_forw_packet_list_steal() - claim a list of forward packets for free()
594 * @forw_list: the to be stolen forward packets
595 * @cleanup_list: a backup pointer, to be able to dispose the packet later
596 * @hard_iface: the interface to steal forward packets from
597 *
598 * This function claims responsibility to free any forw_packet queued on the
599 * given hard_iface. If hard_iface is NULL forwarding packets on all hard
600 * interfaces will be claimed.
601 *
602 * The packets are being moved from the forw_list to the cleanup_list. This
603 * makes it possible for already running threads to notice the claim.
604 */
605 static void
606 batadv_forw_packet_list_steal(struct hlist_head *forw_list,
607 struct hlist_head *cleanup_list,
608 const struct batadv_hard_iface *hard_iface)
609 {
610 struct batadv_forw_packet *forw_packet;
611 struct hlist_node *safe_tmp_node;
612
613 hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
614 forw_list, list) {
615 /* if purge_outstanding_packets() was called with an argument
616 * we delete only packets belonging to the given interface
617 */
618 if (hard_iface &&
619 forw_packet->if_incoming != hard_iface &&
620 forw_packet->if_outgoing != hard_iface)
621 continue;
622
623 hlist_del(&forw_packet->list);
624 hlist_add_head(&forw_packet->cleanup_list, cleanup_list);
625 }
626 }
627
628 /**
629 * batadv_forw_packet_list_free() - free a list of forward packets
630 * @head: a list of to be freed forw_packets
631 *
632 * This function cancels the scheduling of any packet in the provided list,
633 * waits for any possibly running packet forwarding thread to finish and
634 * finally, safely frees this forward packet.
635 *
636 * This function might sleep.
637 */
638 static void batadv_forw_packet_list_free(struct hlist_head *head)
639 {
640 struct batadv_forw_packet *forw_packet;
641 struct hlist_node *safe_tmp_node;
642
643 hlist_for_each_entry_safe(forw_packet, safe_tmp_node, head,
644 cleanup_list) {
645 cancel_delayed_work_sync(&forw_packet->delayed_work);
646
647 hlist_del(&forw_packet->cleanup_list);
648 batadv_forw_packet_free(forw_packet, true);
649 }
650 }
651
652 /**
653 * batadv_forw_packet_queue() - try to queue a forwarding packet
654 * @forw_packet: the forwarding packet to queue
655 * @lock: a key to the store (e.g. forw_{bat,bcast}_list_lock)
656 * @head: the shelve to queue it on (e.g. forw_{bat,bcast}_list)
657 * @send_time: timestamp (jiffies) when the packet is to be sent
658 *
659 * This function tries to (re)queue a forwarding packet. Requeuing
660 * is prevented if the according interface is shutting down
661 * (e.g. if batadv_forw_packet_list_steal() was called for this
662 * packet earlier).
663 *
664 * Calling batadv_forw_packet_queue() after a call to
665 * batadv_forw_packet_steal() is forbidden!
666 *
667 * Caller needs to ensure that forw_packet->delayed_work was initialized.
668 */
669 static void batadv_forw_packet_queue(struct batadv_forw_packet *forw_packet,
670 spinlock_t *lock, struct hlist_head *head,
671 unsigned long send_time)
672 {
673 spin_lock_bh(lock);
674
675 /* did purging routine steal it from us? */
676 if (batadv_forw_packet_was_stolen(forw_packet)) {
677 /* If you got it for free() without trouble, then
678 * don't get back into the queue after stealing...
679 */
680 WARN_ONCE(hlist_fake(&forw_packet->cleanup_list),
681 "Requeuing after batadv_forw_packet_steal() not allowed!\n");
682
683 spin_unlock_bh(lock);
684 return;
685 }
686
687 hlist_del_init(&forw_packet->list);
688 hlist_add_head(&forw_packet->list, head);
689
690 queue_delayed_work(batadv_event_workqueue,
691 &forw_packet->delayed_work,
692 send_time - jiffies);
693 spin_unlock_bh(lock);
694 }
695
696 /**
697 * batadv_forw_packet_bcast_queue() - try to queue a broadcast packet
698 * @bat_priv: the bat priv with all the soft interface information
699 * @forw_packet: the forwarding packet to queue
700 * @send_time: timestamp (jiffies) when the packet is to be sent
701 *
702 * This function tries to (re)queue a broadcast packet.
703 *
704 * Caller needs to ensure that forw_packet->delayed_work was initialized.
705 */
706 static void
707 batadv_forw_packet_bcast_queue(struct batadv_priv *bat_priv,
708 struct batadv_forw_packet *forw_packet,
709 unsigned long send_time)
710 {
711 batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bcast_list_lock,
712 &bat_priv->forw_bcast_list, send_time);
713 }
714
715 /**
716 * batadv_forw_packet_ogmv1_queue() - try to queue an OGMv1 packet
717 * @bat_priv: the bat priv with all the soft interface information
718 * @forw_packet: the forwarding packet to queue
719 * @send_time: timestamp (jiffies) when the packet is to be sent
720 *
721 * This function tries to (re)queue an OGMv1 packet.
722 *
723 * Caller needs to ensure that forw_packet->delayed_work was initialized.
724 */
725 void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv,
726 struct batadv_forw_packet *forw_packet,
727 unsigned long send_time)
728 {
729 batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bat_list_lock,
730 &bat_priv->forw_bat_list, send_time);
731 }
732
733 /**
734 * batadv_forw_bcast_packet_to_list() - queue broadcast packet for transmissions
735 * @bat_priv: the bat priv with all the soft interface information
736 * @skb: broadcast packet to add
737 * @delay: number of jiffies to wait before sending
738 * @own_packet: true if it is a self-generated broadcast packet
739 * @if_in: the interface where the packet was received on
740 * @if_out: the outgoing interface to queue on
741 *
742 * Adds a broadcast packet to the queue and sets up timers. Broadcast packets
743 * are sent multiple times to increase probability for being received.
744 *
745 * This call clones the given skb, hence the caller needs to take into
746 * account that the data segment of the original skb might not be
747 * modifiable anymore.
748 *
749 * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
750 */
751 static int batadv_forw_bcast_packet_to_list(struct batadv_priv *bat_priv,
752 struct sk_buff *skb,
753 unsigned long delay,
754 bool own_packet,
755 struct batadv_hard_iface *if_in,
756 struct batadv_hard_iface *if_out)
757 {
758 struct batadv_forw_packet *forw_packet;
759 unsigned long send_time = jiffies;
760 struct sk_buff *newskb;
761
762 newskb = skb_clone(skb, GFP_ATOMIC);
763 if (!newskb)
764 goto err;
765
766 forw_packet = batadv_forw_packet_alloc(if_in, if_out,
767 &bat_priv->bcast_queue_left,
768 bat_priv, newskb);
769 if (!forw_packet)
770 goto err_packet_free;
771
772 forw_packet->own = own_packet;
773
774 INIT_DELAYED_WORK(&forw_packet->delayed_work,
775 batadv_send_outstanding_bcast_packet);
776
777 send_time += delay ? delay : msecs_to_jiffies(5);
778
779 batadv_forw_packet_bcast_queue(bat_priv, forw_packet, send_time);
780 return NETDEV_TX_OK;
781
782 err_packet_free:
783 kfree_skb(newskb);
784 err:
785 return NETDEV_TX_BUSY;
786 }
787
788 /**
789 * batadv_forw_bcast_packet_if() - forward and queue a broadcast packet
790 * @bat_priv: the bat priv with all the soft interface information
791 * @skb: broadcast packet to add
792 * @delay: number of jiffies to wait before sending
793 * @own_packet: true if it is a self-generated broadcast packet
794 * @if_in: the interface where the packet was received on
795 * @if_out: the outgoing interface to forward to
796 *
797 * Transmits a broadcast packet on the specified interface either immediately
798 * or if a delay is given after that. Furthermore, queues additional
799 * retransmissions if this interface is a wireless one.
800 *
801 * This call clones the given skb, hence the caller needs to take into
802 * account that the data segment of the original skb might not be
803 * modifiable anymore.
804 *
805 * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
806 */
807 static int batadv_forw_bcast_packet_if(struct batadv_priv *bat_priv,
808 struct sk_buff *skb,
809 unsigned long delay,
810 bool own_packet,
811 struct batadv_hard_iface *if_in,
812 struct batadv_hard_iface *if_out)
813 {
814 unsigned int num_bcasts = if_out->num_bcasts;
815 struct sk_buff *newskb;
816 int ret = NETDEV_TX_OK;
817
818 if (!delay) {
819 newskb = skb_clone(skb, GFP_ATOMIC);
820 if (!newskb)
821 return NETDEV_TX_BUSY;
822
823 batadv_send_broadcast_skb(newskb, if_out);
824 num_bcasts--;
825 }
826
827 /* delayed broadcast or rebroadcasts? */
828 if (num_bcasts >= 1) {
829 BATADV_SKB_CB(skb)->num_bcasts = num_bcasts;
830
831 ret = batadv_forw_bcast_packet_to_list(bat_priv, skb, delay,
832 own_packet, if_in,
833 if_out);
834 }
835
836 return ret;
837 }
838
839 /**
840 * batadv_send_no_broadcast() - check whether (re)broadcast is necessary
841 * @bat_priv: the bat priv with all the soft interface information
842 * @skb: broadcast packet to check
843 * @own_packet: true if it is a self-generated broadcast packet
844 * @if_out: the outgoing interface checked and considered for (re)broadcast
845 *
846 * Return: False if a packet needs to be (re)broadcasted on the given interface,
847 * true otherwise.
848 */
849 static bool batadv_send_no_broadcast(struct batadv_priv *bat_priv,
850 struct sk_buff *skb, bool own_packet,
851 struct batadv_hard_iface *if_out)
852 {
853 struct batadv_hardif_neigh_node *neigh_node = NULL;
854 struct batadv_bcast_packet *bcast_packet;
855 u8 *orig_neigh;
856 u8 *neigh_addr;
857 char *type;
858 int ret;
859
860 if (!own_packet) {
861 neigh_addr = eth_hdr(skb)->h_source;
862 neigh_node = batadv_hardif_neigh_get(if_out,
863 neigh_addr);
864 }
865
866 bcast_packet = (struct batadv_bcast_packet *)skb->data;
867 orig_neigh = neigh_node ? neigh_node->orig : NULL;
868
869 ret = batadv_hardif_no_broadcast(if_out, bcast_packet->orig,
870 orig_neigh);
871
872 batadv_hardif_neigh_put(neigh_node);
873
874 /* ok, may broadcast */
875 if (!ret)
876 return false;
877
878 /* no broadcast */
879 switch (ret) {
880 case BATADV_HARDIF_BCAST_NORECIPIENT:
881 type = "no neighbor";
882 break;
883 case BATADV_HARDIF_BCAST_DUPFWD:
884 type = "single neighbor is source";
885 break;
886 case BATADV_HARDIF_BCAST_DUPORIG:
887 type = "single neighbor is originator";
888 break;
889 default:
890 type = "unknown";
891 }
892
893 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
894 "BCAST packet from orig %pM on %s suppressed: %s\n",
895 bcast_packet->orig,
896 if_out->net_dev->name, type);
897
898 return true;
899 }
900
901 /**
902 * __batadv_forw_bcast_packet() - forward and queue a broadcast packet
903 * @bat_priv: the bat priv with all the soft interface information
904 * @skb: broadcast packet to add
905 * @delay: number of jiffies to wait before sending
906 * @own_packet: true if it is a self-generated broadcast packet
907 *
908 * Transmits a broadcast packet either immediately or if a delay is given
909 * after that. Furthermore, queues additional retransmissions on wireless
910 * interfaces.
911 *
912 * This call clones the given skb, hence the caller needs to take into
913 * account that the data segment of the given skb might not be
914 * modifiable anymore.
915 *
916 * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
917 */
918 static int __batadv_forw_bcast_packet(struct batadv_priv *bat_priv,
919 struct sk_buff *skb,
920 unsigned long delay,
921 bool own_packet)
922 {
923 struct batadv_hard_iface *hard_iface;
924 struct batadv_hard_iface *primary_if;
925 int ret = NETDEV_TX_OK;
926
927 primary_if = batadv_primary_if_get_selected(bat_priv);
928 if (!primary_if)
929 return NETDEV_TX_BUSY;
930
931 rcu_read_lock();
932 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
933 if (hard_iface->soft_iface != bat_priv->soft_iface)
934 continue;
935
936 if (!kref_get_unless_zero(&hard_iface->refcount))
937 continue;
938
939 if (batadv_send_no_broadcast(bat_priv, skb, own_packet,
940 hard_iface)) {
941 batadv_hardif_put(hard_iface);
942 continue;
943 }
944
945 ret = batadv_forw_bcast_packet_if(bat_priv, skb, delay,
946 own_packet, primary_if,
947 hard_iface);
948 batadv_hardif_put(hard_iface);
949
950 if (ret == NETDEV_TX_BUSY)
951 break;
952 }
953 rcu_read_unlock();
954
955 batadv_hardif_put(primary_if);
956 return ret;
957 }
958
959 /**
960 * batadv_forw_bcast_packet() - forward and queue a broadcast packet
961 * @bat_priv: the bat priv with all the soft interface information
962 * @skb: broadcast packet to add
963 * @delay: number of jiffies to wait before sending
964 * @own_packet: true if it is a self-generated broadcast packet
965 *
966 * Transmits a broadcast packet either immediately or if a delay is given
967 * after that. Furthermore, queues additional retransmissions on wireless
968 * interfaces.
969 *
970 * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
971 */
972 int batadv_forw_bcast_packet(struct batadv_priv *bat_priv,
973 struct sk_buff *skb,
974 unsigned long delay,
975 bool own_packet)
976 {
977 return __batadv_forw_bcast_packet(bat_priv, skb, delay, own_packet);
978 }
979
980 /**
981 * batadv_send_bcast_packet() - send and queue a broadcast packet
982 * @bat_priv: the bat priv with all the soft interface information
983 * @skb: broadcast packet to add
984 * @delay: number of jiffies to wait before sending
985 * @own_packet: true if it is a self-generated broadcast packet
986 *
987 * Transmits a broadcast packet either immediately or if a delay is given
988 * after that. Furthermore, queues additional retransmissions on wireless
989 * interfaces.
990 *
991 * Consumes the provided skb.
992 */
993 void batadv_send_bcast_packet(struct batadv_priv *bat_priv,
994 struct sk_buff *skb,
995 unsigned long delay,
996 bool own_packet)
997 {
998 __batadv_forw_bcast_packet(bat_priv, skb, delay, own_packet);
999 consume_skb(skb);
1000 }
1001
1002 /**
1003 * batadv_forw_packet_bcasts_left() - check if a retransmission is necessary
1004 * @forw_packet: the forwarding packet to check
1005 *
1006 * Checks whether a given packet has any (re)transmissions left on the provided
1007 * interface.
1008 *
1009 * hard_iface may be NULL: In that case the number of transmissions this skb had
1010 * so far is compared with the maximum amount of retransmissions independent of
1011 * any interface instead.
1012 *
1013 * Return: True if (re)transmissions are left, false otherwise.
1014 */
1015 static bool
1016 batadv_forw_packet_bcasts_left(struct batadv_forw_packet *forw_packet)
1017 {
1018 return BATADV_SKB_CB(forw_packet->skb)->num_bcasts;
1019 }
1020
1021 /**
1022 * batadv_forw_packet_bcasts_dec() - decrement retransmission counter of a
1023 * packet
1024 * @forw_packet: the packet to decrease the counter for
1025 */
1026 static void
1027 batadv_forw_packet_bcasts_dec(struct batadv_forw_packet *forw_packet)
1028 {
1029 BATADV_SKB_CB(forw_packet->skb)->num_bcasts--;
1030 }
1031
1032 /**
1033 * batadv_forw_packet_is_rebroadcast() - check packet for previous transmissions
1034 * @forw_packet: the packet to check
1035 *
1036 * Return: True if this packet was transmitted before, false otherwise.
1037 */
1038 bool batadv_forw_packet_is_rebroadcast(struct batadv_forw_packet *forw_packet)
1039 {
1040 unsigned char num_bcasts = BATADV_SKB_CB(forw_packet->skb)->num_bcasts;
1041
1042 return num_bcasts != forw_packet->if_outgoing->num_bcasts;
1043 }
1044
1045 /**
1046 * batadv_send_outstanding_bcast_packet() - transmit a queued broadcast packet
1047 * @work: work queue item
1048 *
1049 * Transmits a queued broadcast packet and if necessary reschedules it.
1050 */
1051 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
1052 {
1053 unsigned long send_time = jiffies + msecs_to_jiffies(5);
1054 struct batadv_forw_packet *forw_packet;
1055 struct delayed_work *delayed_work;
1056 struct batadv_priv *bat_priv;
1057 struct sk_buff *skb1;
1058 bool dropped = false;
1059
1060 delayed_work = to_delayed_work(work);
1061 forw_packet = container_of(delayed_work, struct batadv_forw_packet,
1062 delayed_work);
1063 bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
1064
1065 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
1066 dropped = true;
1067 goto out;
1068 }
1069
1070 if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) {
1071 dropped = true;
1072 goto out;
1073 }
1074
1075 /* send a copy of the saved skb */
1076 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
1077 if (!skb1)
1078 goto out;
1079
1080 batadv_send_broadcast_skb(skb1, forw_packet->if_outgoing);
1081 batadv_forw_packet_bcasts_dec(forw_packet);
1082
1083 if (batadv_forw_packet_bcasts_left(forw_packet)) {
1084 batadv_forw_packet_bcast_queue(bat_priv, forw_packet,
1085 send_time);
1086 return;
1087 }
1088
1089 out:
1090 /* do we get something for free()? */
1091 if (batadv_forw_packet_steal(forw_packet,
1092 &bat_priv->forw_bcast_list_lock))
1093 batadv_forw_packet_free(forw_packet, dropped);
1094 }
1095
1096 /**
1097 * batadv_purge_outstanding_packets() - stop/purge scheduled bcast/OGMv1 packets
1098 * @bat_priv: the bat priv with all the soft interface information
1099 * @hard_iface: the hard interface to cancel and purge bcast/ogm packets on
1100 *
1101 * This method cancels and purges any broadcast and OGMv1 packet on the given
1102 * hard_iface. If hard_iface is NULL, broadcast and OGMv1 packets on all hard
1103 * interfaces will be canceled and purged.
1104 *
1105 * This function might sleep.
1106 */
1107 void
1108 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
1109 const struct batadv_hard_iface *hard_iface)
1110 {
1111 struct hlist_head head = HLIST_HEAD_INIT;
1112
1113 if (hard_iface)
1114 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1115 "%s(): %s\n",
1116 __func__, hard_iface->net_dev->name);
1117 else
1118 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1119 "%s()\n", __func__);
1120
1121 /* claim bcast list for free() */
1122 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
1123 batadv_forw_packet_list_steal(&bat_priv->forw_bcast_list, &head,
1124 hard_iface);
1125 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
1126
1127 /* claim batman packet list for free() */
1128 spin_lock_bh(&bat_priv->forw_bat_list_lock);
1129 batadv_forw_packet_list_steal(&bat_priv->forw_bat_list, &head,
1130 hard_iface);
1131 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
1132
1133 /* then cancel or wait for packet workers to finish and free */
1134 batadv_forw_packet_list_free(&head);
1135 }
1136
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