xref: /openbmc/linux/net/batman-adv/tvlv.c (revision 6d99a79c)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2007-2018  B.A.T.M.A.N. contributors:
3  *
4  * Marek Lindner, Simon Wunderlich
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of version 2 of the GNU General Public
8  * License as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include "main.h"
20 
21 #include <linux/byteorder/generic.h>
22 #include <linux/etherdevice.h>
23 #include <linux/gfp.h>
24 #include <linux/if_ether.h>
25 #include <linux/kernel.h>
26 #include <linux/kref.h>
27 #include <linux/list.h>
28 #include <linux/lockdep.h>
29 #include <linux/netdevice.h>
30 #include <linux/pkt_sched.h>
31 #include <linux/rculist.h>
32 #include <linux/rcupdate.h>
33 #include <linux/skbuff.h>
34 #include <linux/slab.h>
35 #include <linux/spinlock.h>
36 #include <linux/stddef.h>
37 #include <linux/string.h>
38 #include <linux/types.h>
39 #include <uapi/linux/batadv_packet.h>
40 
41 #include "originator.h"
42 #include "send.h"
43 #include "tvlv.h"
44 
45 /**
46  * batadv_tvlv_handler_release() - release tvlv handler from lists and queue for
47  *  free after rcu grace period
48  * @ref: kref pointer of the tvlv
49  */
50 static void batadv_tvlv_handler_release(struct kref *ref)
51 {
52 	struct batadv_tvlv_handler *tvlv_handler;
53 
54 	tvlv_handler = container_of(ref, struct batadv_tvlv_handler, refcount);
55 	kfree_rcu(tvlv_handler, rcu);
56 }
57 
58 /**
59  * batadv_tvlv_handler_put() - decrement the tvlv container refcounter and
60  *  possibly release it
61  * @tvlv_handler: the tvlv handler to free
62  */
63 static void batadv_tvlv_handler_put(struct batadv_tvlv_handler *tvlv_handler)
64 {
65 	kref_put(&tvlv_handler->refcount, batadv_tvlv_handler_release);
66 }
67 
68 /**
69  * batadv_tvlv_handler_get() - retrieve tvlv handler from the tvlv handler list
70  *  based on the provided type and version (both need to match)
71  * @bat_priv: the bat priv with all the soft interface information
72  * @type: tvlv handler type to look for
73  * @version: tvlv handler version to look for
74  *
75  * Return: tvlv handler if found or NULL otherwise.
76  */
77 static struct batadv_tvlv_handler *
78 batadv_tvlv_handler_get(struct batadv_priv *bat_priv, u8 type, u8 version)
79 {
80 	struct batadv_tvlv_handler *tvlv_handler_tmp, *tvlv_handler = NULL;
81 
82 	rcu_read_lock();
83 	hlist_for_each_entry_rcu(tvlv_handler_tmp,
84 				 &bat_priv->tvlv.handler_list, list) {
85 		if (tvlv_handler_tmp->type != type)
86 			continue;
87 
88 		if (tvlv_handler_tmp->version != version)
89 			continue;
90 
91 		if (!kref_get_unless_zero(&tvlv_handler_tmp->refcount))
92 			continue;
93 
94 		tvlv_handler = tvlv_handler_tmp;
95 		break;
96 	}
97 	rcu_read_unlock();
98 
99 	return tvlv_handler;
100 }
101 
102 /**
103  * batadv_tvlv_container_release() - release tvlv from lists and free
104  * @ref: kref pointer of the tvlv
105  */
106 static void batadv_tvlv_container_release(struct kref *ref)
107 {
108 	struct batadv_tvlv_container *tvlv;
109 
110 	tvlv = container_of(ref, struct batadv_tvlv_container, refcount);
111 	kfree(tvlv);
112 }
113 
114 /**
115  * batadv_tvlv_container_put() - decrement the tvlv container refcounter and
116  *  possibly release it
117  * @tvlv: the tvlv container to free
118  */
119 static void batadv_tvlv_container_put(struct batadv_tvlv_container *tvlv)
120 {
121 	kref_put(&tvlv->refcount, batadv_tvlv_container_release);
122 }
123 
124 /**
125  * batadv_tvlv_container_get() - retrieve tvlv container from the tvlv container
126  *  list based on the provided type and version (both need to match)
127  * @bat_priv: the bat priv with all the soft interface information
128  * @type: tvlv container type to look for
129  * @version: tvlv container version to look for
130  *
131  * Has to be called with the appropriate locks being acquired
132  * (tvlv.container_list_lock).
133  *
134  * Return: tvlv container if found or NULL otherwise.
135  */
136 static struct batadv_tvlv_container *
137 batadv_tvlv_container_get(struct batadv_priv *bat_priv, u8 type, u8 version)
138 {
139 	struct batadv_tvlv_container *tvlv_tmp, *tvlv = NULL;
140 
141 	lockdep_assert_held(&bat_priv->tvlv.container_list_lock);
142 
143 	hlist_for_each_entry(tvlv_tmp, &bat_priv->tvlv.container_list, list) {
144 		if (tvlv_tmp->tvlv_hdr.type != type)
145 			continue;
146 
147 		if (tvlv_tmp->tvlv_hdr.version != version)
148 			continue;
149 
150 		kref_get(&tvlv_tmp->refcount);
151 		tvlv = tvlv_tmp;
152 		break;
153 	}
154 
155 	return tvlv;
156 }
157 
158 /**
159  * batadv_tvlv_container_list_size() - calculate the size of the tvlv container
160  *  list entries
161  * @bat_priv: the bat priv with all the soft interface information
162  *
163  * Has to be called with the appropriate locks being acquired
164  * (tvlv.container_list_lock).
165  *
166  * Return: size of all currently registered tvlv containers in bytes.
167  */
168 static u16 batadv_tvlv_container_list_size(struct batadv_priv *bat_priv)
169 {
170 	struct batadv_tvlv_container *tvlv;
171 	u16 tvlv_len = 0;
172 
173 	lockdep_assert_held(&bat_priv->tvlv.container_list_lock);
174 
175 	hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
176 		tvlv_len += sizeof(struct batadv_tvlv_hdr);
177 		tvlv_len += ntohs(tvlv->tvlv_hdr.len);
178 	}
179 
180 	return tvlv_len;
181 }
182 
183 /**
184  * batadv_tvlv_container_remove() - remove tvlv container from the tvlv
185  *  container list
186  * @bat_priv: the bat priv with all the soft interface information
187  * @tvlv: the to be removed tvlv container
188  *
189  * Has to be called with the appropriate locks being acquired
190  * (tvlv.container_list_lock).
191  */
192 static void batadv_tvlv_container_remove(struct batadv_priv *bat_priv,
193 					 struct batadv_tvlv_container *tvlv)
194 {
195 	lockdep_assert_held(&bat_priv->tvlv.container_list_lock);
196 
197 	if (!tvlv)
198 		return;
199 
200 	hlist_del(&tvlv->list);
201 
202 	/* first call to decrement the counter, second call to free */
203 	batadv_tvlv_container_put(tvlv);
204 	batadv_tvlv_container_put(tvlv);
205 }
206 
207 /**
208  * batadv_tvlv_container_unregister() - unregister tvlv container based on the
209  *  provided type and version (both need to match)
210  * @bat_priv: the bat priv with all the soft interface information
211  * @type: tvlv container type to unregister
212  * @version: tvlv container type to unregister
213  */
214 void batadv_tvlv_container_unregister(struct batadv_priv *bat_priv,
215 				      u8 type, u8 version)
216 {
217 	struct batadv_tvlv_container *tvlv;
218 
219 	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
220 	tvlv = batadv_tvlv_container_get(bat_priv, type, version);
221 	batadv_tvlv_container_remove(bat_priv, tvlv);
222 	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
223 }
224 
225 /**
226  * batadv_tvlv_container_register() - register tvlv type, version and content
227  *  to be propagated with each (primary interface) OGM
228  * @bat_priv: the bat priv with all the soft interface information
229  * @type: tvlv container type
230  * @version: tvlv container version
231  * @tvlv_value: tvlv container content
232  * @tvlv_value_len: tvlv container content length
233  *
234  * If a container of the same type and version was already registered the new
235  * content is going to replace the old one.
236  */
237 void batadv_tvlv_container_register(struct batadv_priv *bat_priv,
238 				    u8 type, u8 version,
239 				    void *tvlv_value, u16 tvlv_value_len)
240 {
241 	struct batadv_tvlv_container *tvlv_old, *tvlv_new;
242 
243 	if (!tvlv_value)
244 		tvlv_value_len = 0;
245 
246 	tvlv_new = kzalloc(sizeof(*tvlv_new) + tvlv_value_len, GFP_ATOMIC);
247 	if (!tvlv_new)
248 		return;
249 
250 	tvlv_new->tvlv_hdr.version = version;
251 	tvlv_new->tvlv_hdr.type = type;
252 	tvlv_new->tvlv_hdr.len = htons(tvlv_value_len);
253 
254 	memcpy(tvlv_new + 1, tvlv_value, ntohs(tvlv_new->tvlv_hdr.len));
255 	INIT_HLIST_NODE(&tvlv_new->list);
256 	kref_init(&tvlv_new->refcount);
257 
258 	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
259 	tvlv_old = batadv_tvlv_container_get(bat_priv, type, version);
260 	batadv_tvlv_container_remove(bat_priv, tvlv_old);
261 
262 	kref_get(&tvlv_new->refcount);
263 	hlist_add_head(&tvlv_new->list, &bat_priv->tvlv.container_list);
264 	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
265 
266 	/* don't return reference to new tvlv_container */
267 	batadv_tvlv_container_put(tvlv_new);
268 }
269 
270 /**
271  * batadv_tvlv_realloc_packet_buff() - reallocate packet buffer to accommodate
272  *  requested packet size
273  * @packet_buff: packet buffer
274  * @packet_buff_len: packet buffer size
275  * @min_packet_len: requested packet minimum size
276  * @additional_packet_len: requested additional packet size on top of minimum
277  *  size
278  *
279  * Return: true of the packet buffer could be changed to the requested size,
280  * false otherwise.
281  */
282 static bool batadv_tvlv_realloc_packet_buff(unsigned char **packet_buff,
283 					    int *packet_buff_len,
284 					    int min_packet_len,
285 					    int additional_packet_len)
286 {
287 	unsigned char *new_buff;
288 
289 	new_buff = kmalloc(min_packet_len + additional_packet_len, GFP_ATOMIC);
290 
291 	/* keep old buffer if kmalloc should fail */
292 	if (!new_buff)
293 		return false;
294 
295 	memcpy(new_buff, *packet_buff, min_packet_len);
296 	kfree(*packet_buff);
297 	*packet_buff = new_buff;
298 	*packet_buff_len = min_packet_len + additional_packet_len;
299 
300 	return true;
301 }
302 
303 /**
304  * batadv_tvlv_container_ogm_append() - append tvlv container content to given
305  *  OGM packet buffer
306  * @bat_priv: the bat priv with all the soft interface information
307  * @packet_buff: ogm packet buffer
308  * @packet_buff_len: ogm packet buffer size including ogm header and tvlv
309  *  content
310  * @packet_min_len: ogm header size to be preserved for the OGM itself
311  *
312  * The ogm packet might be enlarged or shrunk depending on the current size
313  * and the size of the to-be-appended tvlv containers.
314  *
315  * Return: size of all appended tvlv containers in bytes.
316  */
317 u16 batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv,
318 				     unsigned char **packet_buff,
319 				     int *packet_buff_len, int packet_min_len)
320 {
321 	struct batadv_tvlv_container *tvlv;
322 	struct batadv_tvlv_hdr *tvlv_hdr;
323 	u16 tvlv_value_len;
324 	void *tvlv_value;
325 	bool ret;
326 
327 	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
328 	tvlv_value_len = batadv_tvlv_container_list_size(bat_priv);
329 
330 	ret = batadv_tvlv_realloc_packet_buff(packet_buff, packet_buff_len,
331 					      packet_min_len, tvlv_value_len);
332 
333 	if (!ret)
334 		goto end;
335 
336 	if (!tvlv_value_len)
337 		goto end;
338 
339 	tvlv_value = (*packet_buff) + packet_min_len;
340 
341 	hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
342 		tvlv_hdr = tvlv_value;
343 		tvlv_hdr->type = tvlv->tvlv_hdr.type;
344 		tvlv_hdr->version = tvlv->tvlv_hdr.version;
345 		tvlv_hdr->len = tvlv->tvlv_hdr.len;
346 		tvlv_value = tvlv_hdr + 1;
347 		memcpy(tvlv_value, tvlv + 1, ntohs(tvlv->tvlv_hdr.len));
348 		tvlv_value = (u8 *)tvlv_value + ntohs(tvlv->tvlv_hdr.len);
349 	}
350 
351 end:
352 	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
353 	return tvlv_value_len;
354 }
355 
356 /**
357  * batadv_tvlv_call_handler() - parse the given tvlv buffer to call the
358  *  appropriate handlers
359  * @bat_priv: the bat priv with all the soft interface information
360  * @tvlv_handler: tvlv callback function handling the tvlv content
361  * @ogm_source: flag indicating whether the tvlv is an ogm or a unicast packet
362  * @orig_node: orig node emitting the ogm packet
363  * @src: source mac address of the unicast packet
364  * @dst: destination mac address of the unicast packet
365  * @tvlv_value: tvlv content
366  * @tvlv_value_len: tvlv content length
367  *
368  * Return: success if handler was not found or the return value of the handler
369  * callback.
370  */
371 static int batadv_tvlv_call_handler(struct batadv_priv *bat_priv,
372 				    struct batadv_tvlv_handler *tvlv_handler,
373 				    bool ogm_source,
374 				    struct batadv_orig_node *orig_node,
375 				    u8 *src, u8 *dst,
376 				    void *tvlv_value, u16 tvlv_value_len)
377 {
378 	if (!tvlv_handler)
379 		return NET_RX_SUCCESS;
380 
381 	if (ogm_source) {
382 		if (!tvlv_handler->ogm_handler)
383 			return NET_RX_SUCCESS;
384 
385 		if (!orig_node)
386 			return NET_RX_SUCCESS;
387 
388 		tvlv_handler->ogm_handler(bat_priv, orig_node,
389 					  BATADV_NO_FLAGS,
390 					  tvlv_value, tvlv_value_len);
391 		tvlv_handler->flags |= BATADV_TVLV_HANDLER_OGM_CALLED;
392 	} else {
393 		if (!src)
394 			return NET_RX_SUCCESS;
395 
396 		if (!dst)
397 			return NET_RX_SUCCESS;
398 
399 		if (!tvlv_handler->unicast_handler)
400 			return NET_RX_SUCCESS;
401 
402 		return tvlv_handler->unicast_handler(bat_priv, src,
403 						     dst, tvlv_value,
404 						     tvlv_value_len);
405 	}
406 
407 	return NET_RX_SUCCESS;
408 }
409 
410 /**
411  * batadv_tvlv_containers_process() - parse the given tvlv buffer to call the
412  *  appropriate handlers
413  * @bat_priv: the bat priv with all the soft interface information
414  * @ogm_source: flag indicating whether the tvlv is an ogm or a unicast packet
415  * @orig_node: orig node emitting the ogm packet
416  * @src: source mac address of the unicast packet
417  * @dst: destination mac address of the unicast packet
418  * @tvlv_value: tvlv content
419  * @tvlv_value_len: tvlv content length
420  *
421  * Return: success when processing an OGM or the return value of all called
422  * handler callbacks.
423  */
424 int batadv_tvlv_containers_process(struct batadv_priv *bat_priv,
425 				   bool ogm_source,
426 				   struct batadv_orig_node *orig_node,
427 				   u8 *src, u8 *dst,
428 				   void *tvlv_value, u16 tvlv_value_len)
429 {
430 	struct batadv_tvlv_handler *tvlv_handler;
431 	struct batadv_tvlv_hdr *tvlv_hdr;
432 	u16 tvlv_value_cont_len;
433 	u8 cifnotfound = BATADV_TVLV_HANDLER_OGM_CIFNOTFND;
434 	int ret = NET_RX_SUCCESS;
435 
436 	while (tvlv_value_len >= sizeof(*tvlv_hdr)) {
437 		tvlv_hdr = tvlv_value;
438 		tvlv_value_cont_len = ntohs(tvlv_hdr->len);
439 		tvlv_value = tvlv_hdr + 1;
440 		tvlv_value_len -= sizeof(*tvlv_hdr);
441 
442 		if (tvlv_value_cont_len > tvlv_value_len)
443 			break;
444 
445 		tvlv_handler = batadv_tvlv_handler_get(bat_priv,
446 						       tvlv_hdr->type,
447 						       tvlv_hdr->version);
448 
449 		ret |= batadv_tvlv_call_handler(bat_priv, tvlv_handler,
450 						ogm_source, orig_node,
451 						src, dst, tvlv_value,
452 						tvlv_value_cont_len);
453 		if (tvlv_handler)
454 			batadv_tvlv_handler_put(tvlv_handler);
455 		tvlv_value = (u8 *)tvlv_value + tvlv_value_cont_len;
456 		tvlv_value_len -= tvlv_value_cont_len;
457 	}
458 
459 	if (!ogm_source)
460 		return ret;
461 
462 	rcu_read_lock();
463 	hlist_for_each_entry_rcu(tvlv_handler,
464 				 &bat_priv->tvlv.handler_list, list) {
465 		if ((tvlv_handler->flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) &&
466 		    !(tvlv_handler->flags & BATADV_TVLV_HANDLER_OGM_CALLED))
467 			tvlv_handler->ogm_handler(bat_priv, orig_node,
468 						  cifnotfound, NULL, 0);
469 
470 		tvlv_handler->flags &= ~BATADV_TVLV_HANDLER_OGM_CALLED;
471 	}
472 	rcu_read_unlock();
473 
474 	return NET_RX_SUCCESS;
475 }
476 
477 /**
478  * batadv_tvlv_ogm_receive() - process an incoming ogm and call the appropriate
479  *  handlers
480  * @bat_priv: the bat priv with all the soft interface information
481  * @batadv_ogm_packet: ogm packet containing the tvlv containers
482  * @orig_node: orig node emitting the ogm packet
483  */
484 void batadv_tvlv_ogm_receive(struct batadv_priv *bat_priv,
485 			     struct batadv_ogm_packet *batadv_ogm_packet,
486 			     struct batadv_orig_node *orig_node)
487 {
488 	void *tvlv_value;
489 	u16 tvlv_value_len;
490 
491 	if (!batadv_ogm_packet)
492 		return;
493 
494 	tvlv_value_len = ntohs(batadv_ogm_packet->tvlv_len);
495 	if (!tvlv_value_len)
496 		return;
497 
498 	tvlv_value = batadv_ogm_packet + 1;
499 
500 	batadv_tvlv_containers_process(bat_priv, true, orig_node, NULL, NULL,
501 				       tvlv_value, tvlv_value_len);
502 }
503 
504 /**
505  * batadv_tvlv_handler_register() - register tvlv handler based on the provided
506  *  type and version (both need to match) for ogm tvlv payload and/or unicast
507  *  payload
508  * @bat_priv: the bat priv with all the soft interface information
509  * @optr: ogm tvlv handler callback function. This function receives the orig
510  *  node, flags and the tvlv content as argument to process.
511  * @uptr: unicast tvlv handler callback function. This function receives the
512  *  source & destination of the unicast packet as well as the tvlv content
513  *  to process.
514  * @type: tvlv handler type to be registered
515  * @version: tvlv handler version to be registered
516  * @flags: flags to enable or disable TVLV API behavior
517  */
518 void batadv_tvlv_handler_register(struct batadv_priv *bat_priv,
519 				  void (*optr)(struct batadv_priv *bat_priv,
520 					       struct batadv_orig_node *orig,
521 					       u8 flags,
522 					       void *tvlv_value,
523 					       u16 tvlv_value_len),
524 				  int (*uptr)(struct batadv_priv *bat_priv,
525 					      u8 *src, u8 *dst,
526 					      void *tvlv_value,
527 					      u16 tvlv_value_len),
528 				  u8 type, u8 version, u8 flags)
529 {
530 	struct batadv_tvlv_handler *tvlv_handler;
531 
532 	spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
533 
534 	tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
535 	if (tvlv_handler) {
536 		spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
537 		batadv_tvlv_handler_put(tvlv_handler);
538 		return;
539 	}
540 
541 	tvlv_handler = kzalloc(sizeof(*tvlv_handler), GFP_ATOMIC);
542 	if (!tvlv_handler) {
543 		spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
544 		return;
545 	}
546 
547 	tvlv_handler->ogm_handler = optr;
548 	tvlv_handler->unicast_handler = uptr;
549 	tvlv_handler->type = type;
550 	tvlv_handler->version = version;
551 	tvlv_handler->flags = flags;
552 	kref_init(&tvlv_handler->refcount);
553 	INIT_HLIST_NODE(&tvlv_handler->list);
554 
555 	kref_get(&tvlv_handler->refcount);
556 	hlist_add_head_rcu(&tvlv_handler->list, &bat_priv->tvlv.handler_list);
557 	spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
558 
559 	/* don't return reference to new tvlv_handler */
560 	batadv_tvlv_handler_put(tvlv_handler);
561 }
562 
563 /**
564  * batadv_tvlv_handler_unregister() - unregister tvlv handler based on the
565  *  provided type and version (both need to match)
566  * @bat_priv: the bat priv with all the soft interface information
567  * @type: tvlv handler type to be unregistered
568  * @version: tvlv handler version to be unregistered
569  */
570 void batadv_tvlv_handler_unregister(struct batadv_priv *bat_priv,
571 				    u8 type, u8 version)
572 {
573 	struct batadv_tvlv_handler *tvlv_handler;
574 
575 	tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
576 	if (!tvlv_handler)
577 		return;
578 
579 	batadv_tvlv_handler_put(tvlv_handler);
580 	spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
581 	hlist_del_rcu(&tvlv_handler->list);
582 	spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
583 	batadv_tvlv_handler_put(tvlv_handler);
584 }
585 
586 /**
587  * batadv_tvlv_unicast_send() - send a unicast packet with tvlv payload to the
588  *  specified host
589  * @bat_priv: the bat priv with all the soft interface information
590  * @src: source mac address of the unicast packet
591  * @dst: destination mac address of the unicast packet
592  * @type: tvlv type
593  * @version: tvlv version
594  * @tvlv_value: tvlv content
595  * @tvlv_value_len: tvlv content length
596  */
597 void batadv_tvlv_unicast_send(struct batadv_priv *bat_priv, u8 *src,
598 			      u8 *dst, u8 type, u8 version,
599 			      void *tvlv_value, u16 tvlv_value_len)
600 {
601 	struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
602 	struct batadv_tvlv_hdr *tvlv_hdr;
603 	struct batadv_orig_node *orig_node;
604 	struct sk_buff *skb;
605 	unsigned char *tvlv_buff;
606 	unsigned int tvlv_len;
607 	ssize_t hdr_len = sizeof(*unicast_tvlv_packet);
608 
609 	orig_node = batadv_orig_hash_find(bat_priv, dst);
610 	if (!orig_node)
611 		return;
612 
613 	tvlv_len = sizeof(*tvlv_hdr) + tvlv_value_len;
614 
615 	skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + hdr_len + tvlv_len);
616 	if (!skb)
617 		goto out;
618 
619 	skb->priority = TC_PRIO_CONTROL;
620 	skb_reserve(skb, ETH_HLEN);
621 	tvlv_buff = skb_put(skb, sizeof(*unicast_tvlv_packet) + tvlv_len);
622 	unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)tvlv_buff;
623 	unicast_tvlv_packet->packet_type = BATADV_UNICAST_TVLV;
624 	unicast_tvlv_packet->version = BATADV_COMPAT_VERSION;
625 	unicast_tvlv_packet->ttl = BATADV_TTL;
626 	unicast_tvlv_packet->reserved = 0;
627 	unicast_tvlv_packet->tvlv_len = htons(tvlv_len);
628 	unicast_tvlv_packet->align = 0;
629 	ether_addr_copy(unicast_tvlv_packet->src, src);
630 	ether_addr_copy(unicast_tvlv_packet->dst, dst);
631 
632 	tvlv_buff = (unsigned char *)(unicast_tvlv_packet + 1);
633 	tvlv_hdr = (struct batadv_tvlv_hdr *)tvlv_buff;
634 	tvlv_hdr->version = version;
635 	tvlv_hdr->type = type;
636 	tvlv_hdr->len = htons(tvlv_value_len);
637 	tvlv_buff += sizeof(*tvlv_hdr);
638 	memcpy(tvlv_buff, tvlv_value, tvlv_value_len);
639 
640 	batadv_send_skb_to_orig(skb, orig_node, NULL);
641 out:
642 	batadv_orig_node_put(orig_node);
643 }
644