xref: /linux/net/tipc/bearer.c (revision ed30aef3c864f99111e16d4ea5cf29488d99a278)
1 /*
2  * net/tipc/bearer.c: TIPC bearer code
3  *
4  * Copyright (c) 1996-2006, 2013-2016, Ericsson AB
5  * Copyright (c) 2004-2006, 2010-2013, Wind River Systems
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the names of the copyright holders nor the names of its
17  *    contributors may be used to endorse or promote products derived from
18  *    this software without specific prior written permission.
19  *
20  * Alternatively, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") version 2 as published by the Free
22  * Software Foundation.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34  * POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #include <net/sock.h>
38 #include "core.h"
39 #include "bearer.h"
40 #include "link.h"
41 #include "discover.h"
42 #include "monitor.h"
43 #include "bcast.h"
44 #include "netlink.h"
45 #include "udp_media.h"
46 #include "trace.h"
47 #include "crypto.h"
48 
49 #define MAX_ADDR_STR 60
50 
51 static struct tipc_media * const media_info_array[] = {
52 	&eth_media_info,
53 #ifdef CONFIG_TIPC_MEDIA_IB
54 	&ib_media_info,
55 #endif
56 #ifdef CONFIG_TIPC_MEDIA_UDP
57 	&udp_media_info,
58 #endif
59 	NULL
60 };
61 
62 static struct tipc_bearer *bearer_get(struct net *net, int bearer_id)
63 {
64 	struct tipc_net *tn = tipc_net(net);
65 
66 	return rcu_dereference(tn->bearer_list[bearer_id]);
67 }
68 
69 static void bearer_disable(struct net *net, struct tipc_bearer *b);
70 static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
71 			   struct packet_type *pt, struct net_device *orig_dev);
72 
73 /**
74  * tipc_media_find - locates specified media object by name
75  */
76 struct tipc_media *tipc_media_find(const char *name)
77 {
78 	u32 i;
79 
80 	for (i = 0; media_info_array[i] != NULL; i++) {
81 		if (!strcmp(media_info_array[i]->name, name))
82 			break;
83 	}
84 	return media_info_array[i];
85 }
86 
87 /**
88  * media_find_id - locates specified media object by type identifier
89  */
90 static struct tipc_media *media_find_id(u8 type)
91 {
92 	u32 i;
93 
94 	for (i = 0; media_info_array[i] != NULL; i++) {
95 		if (media_info_array[i]->type_id == type)
96 			break;
97 	}
98 	return media_info_array[i];
99 }
100 
101 /**
102  * tipc_media_addr_printf - record media address in print buffer
103  */
104 int tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a)
105 {
106 	char addr_str[MAX_ADDR_STR];
107 	struct tipc_media *m;
108 	int ret;
109 
110 	m = media_find_id(a->media_id);
111 
112 	if (m && !m->addr2str(a, addr_str, sizeof(addr_str)))
113 		ret = scnprintf(buf, len, "%s(%s)", m->name, addr_str);
114 	else {
115 		u32 i;
116 
117 		ret = scnprintf(buf, len, "UNKNOWN(%u)", a->media_id);
118 		for (i = 0; i < sizeof(a->value); i++)
119 			ret += scnprintf(buf + ret, len - ret,
120 					    "-%x", a->value[i]);
121 	}
122 	return ret;
123 }
124 
125 /**
126  * bearer_name_validate - validate & (optionally) deconstruct bearer name
127  * @name: ptr to bearer name string
128  * @name_parts: ptr to area for bearer name components (or NULL if not needed)
129  *
130  * Returns 1 if bearer name is valid, otherwise 0.
131  */
132 static int bearer_name_validate(const char *name,
133 				struct tipc_bearer_names *name_parts)
134 {
135 	char name_copy[TIPC_MAX_BEARER_NAME];
136 	char *media_name;
137 	char *if_name;
138 	u32 media_len;
139 	u32 if_len;
140 
141 	/* copy bearer name & ensure length is OK */
142 	if (strscpy(name_copy, name, TIPC_MAX_BEARER_NAME) < 0)
143 		return 0;
144 
145 	/* ensure all component parts of bearer name are present */
146 	media_name = name_copy;
147 	if_name = strchr(media_name, ':');
148 	if (if_name == NULL)
149 		return 0;
150 	*(if_name++) = 0;
151 	media_len = if_name - media_name;
152 	if_len = strlen(if_name) + 1;
153 
154 	/* validate component parts of bearer name */
155 	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
156 	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
157 		return 0;
158 
159 	/* return bearer name components, if necessary */
160 	if (name_parts) {
161 		strcpy(name_parts->media_name, media_name);
162 		strcpy(name_parts->if_name, if_name);
163 	}
164 	return 1;
165 }
166 
167 /**
168  * tipc_bearer_find - locates bearer object with matching bearer name
169  */
170 struct tipc_bearer *tipc_bearer_find(struct net *net, const char *name)
171 {
172 	struct tipc_net *tn = net_generic(net, tipc_net_id);
173 	struct tipc_bearer *b;
174 	u32 i;
175 
176 	for (i = 0; i < MAX_BEARERS; i++) {
177 		b = rtnl_dereference(tn->bearer_list[i]);
178 		if (b && (!strcmp(b->name, name)))
179 			return b;
180 	}
181 	return NULL;
182 }
183 
184 /*     tipc_bearer_get_name - get the bearer name from its id.
185  *     @net: network namespace
186  *     @name: a pointer to the buffer where the name will be stored.
187  *     @bearer_id: the id to get the name from.
188  */
189 int tipc_bearer_get_name(struct net *net, char *name, u32 bearer_id)
190 {
191 	struct tipc_net *tn = tipc_net(net);
192 	struct tipc_bearer *b;
193 
194 	if (bearer_id >= MAX_BEARERS)
195 		return -EINVAL;
196 
197 	b = rtnl_dereference(tn->bearer_list[bearer_id]);
198 	if (!b)
199 		return -EINVAL;
200 
201 	strcpy(name, b->name);
202 	return 0;
203 }
204 
205 void tipc_bearer_add_dest(struct net *net, u32 bearer_id, u32 dest)
206 {
207 	struct tipc_net *tn = net_generic(net, tipc_net_id);
208 	struct tipc_bearer *b;
209 
210 	rcu_read_lock();
211 	b = rcu_dereference(tn->bearer_list[bearer_id]);
212 	if (b)
213 		tipc_disc_add_dest(b->disc);
214 	rcu_read_unlock();
215 }
216 
217 void tipc_bearer_remove_dest(struct net *net, u32 bearer_id, u32 dest)
218 {
219 	struct tipc_net *tn = net_generic(net, tipc_net_id);
220 	struct tipc_bearer *b;
221 
222 	rcu_read_lock();
223 	b = rcu_dereference(tn->bearer_list[bearer_id]);
224 	if (b)
225 		tipc_disc_remove_dest(b->disc);
226 	rcu_read_unlock();
227 }
228 
229 /**
230  * tipc_enable_bearer - enable bearer with the given name
231  */
232 static int tipc_enable_bearer(struct net *net, const char *name,
233 			      u32 disc_domain, u32 prio,
234 			      struct nlattr *attr[])
235 {
236 	struct tipc_net *tn = tipc_net(net);
237 	struct tipc_bearer_names b_names;
238 	int with_this_prio = 1;
239 	struct tipc_bearer *b;
240 	struct tipc_media *m;
241 	struct sk_buff *skb;
242 	int bearer_id = 0;
243 	int res = -EINVAL;
244 	char *errstr = "";
245 
246 	if (!bearer_name_validate(name, &b_names)) {
247 		errstr = "illegal name";
248 		goto rejected;
249 	}
250 
251 	if (prio > TIPC_MAX_LINK_PRI && prio != TIPC_MEDIA_LINK_PRI) {
252 		errstr = "illegal priority";
253 		goto rejected;
254 	}
255 
256 	m = tipc_media_find(b_names.media_name);
257 	if (!m) {
258 		errstr = "media not registered";
259 		goto rejected;
260 	}
261 
262 	if (prio == TIPC_MEDIA_LINK_PRI)
263 		prio = m->priority;
264 
265 	/* Check new bearer vs existing ones and find free bearer id if any */
266 	while (bearer_id < MAX_BEARERS) {
267 		b = rtnl_dereference(tn->bearer_list[bearer_id]);
268 		if (!b)
269 			break;
270 		if (!strcmp(name, b->name)) {
271 			errstr = "already enabled";
272 			goto rejected;
273 		}
274 		bearer_id++;
275 		if (b->priority != prio)
276 			continue;
277 		if (++with_this_prio <= 2)
278 			continue;
279 		pr_warn("Bearer <%s>: already 2 bearers with priority %u\n",
280 			name, prio);
281 		if (prio == TIPC_MIN_LINK_PRI) {
282 			errstr = "cannot adjust to lower";
283 			goto rejected;
284 		}
285 		pr_warn("Bearer <%s>: trying with adjusted priority\n", name);
286 		prio--;
287 		bearer_id = 0;
288 		with_this_prio = 1;
289 	}
290 
291 	if (bearer_id >= MAX_BEARERS) {
292 		errstr = "max 3 bearers permitted";
293 		goto rejected;
294 	}
295 
296 	b = kzalloc(sizeof(*b), GFP_ATOMIC);
297 	if (!b)
298 		return -ENOMEM;
299 
300 	strcpy(b->name, name);
301 	b->media = m;
302 	res = m->enable_media(net, b, attr);
303 	if (res) {
304 		kfree(b);
305 		errstr = "failed to enable media";
306 		goto rejected;
307 	}
308 
309 	b->identity = bearer_id;
310 	b->tolerance = m->tolerance;
311 	b->min_win = m->min_win;
312 	b->max_win = m->max_win;
313 	b->domain = disc_domain;
314 	b->net_plane = bearer_id + 'A';
315 	b->priority = prio;
316 	refcount_set(&b->refcnt, 1);
317 
318 	res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
319 	if (res) {
320 		bearer_disable(net, b);
321 		errstr = "failed to create discoverer";
322 		goto rejected;
323 	}
324 
325 	test_and_set_bit_lock(0, &b->up);
326 	rcu_assign_pointer(tn->bearer_list[bearer_id], b);
327 	if (skb)
328 		tipc_bearer_xmit_skb(net, bearer_id, skb, &b->bcast_addr);
329 
330 	if (tipc_mon_create(net, bearer_id)) {
331 		bearer_disable(net, b);
332 		return -ENOMEM;
333 	}
334 
335 	pr_info("Enabled bearer <%s>, priority %u\n", name, prio);
336 
337 	return res;
338 rejected:
339 	pr_warn("Enabling of bearer <%s> rejected, %s\n", name, errstr);
340 	return res;
341 }
342 
343 /**
344  * tipc_reset_bearer - Reset all links established over this bearer
345  */
346 static int tipc_reset_bearer(struct net *net, struct tipc_bearer *b)
347 {
348 	pr_info("Resetting bearer <%s>\n", b->name);
349 	tipc_node_delete_links(net, b->identity);
350 	tipc_disc_reset(net, b);
351 	return 0;
352 }
353 
354 bool tipc_bearer_hold(struct tipc_bearer *b)
355 {
356 	return (b && refcount_inc_not_zero(&b->refcnt));
357 }
358 
359 void tipc_bearer_put(struct tipc_bearer *b)
360 {
361 	if (b && refcount_dec_and_test(&b->refcnt))
362 		kfree_rcu(b, rcu);
363 }
364 
365 /**
366  * bearer_disable
367  *
368  * Note: This routine assumes caller holds RTNL lock.
369  */
370 static void bearer_disable(struct net *net, struct tipc_bearer *b)
371 {
372 	struct tipc_net *tn = tipc_net(net);
373 	int bearer_id = b->identity;
374 
375 	pr_info("Disabling bearer <%s>\n", b->name);
376 	clear_bit_unlock(0, &b->up);
377 	tipc_node_delete_links(net, bearer_id);
378 	b->media->disable_media(b);
379 	RCU_INIT_POINTER(b->media_ptr, NULL);
380 	if (b->disc)
381 		tipc_disc_delete(b->disc);
382 	RCU_INIT_POINTER(tn->bearer_list[bearer_id], NULL);
383 	tipc_bearer_put(b);
384 	tipc_mon_delete(net, bearer_id);
385 }
386 
387 int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
388 			 struct nlattr *attr[])
389 {
390 	char *dev_name = strchr((const char *)b->name, ':') + 1;
391 	int hwaddr_len = b->media->hwaddr_len;
392 	u8 node_id[NODE_ID_LEN] = {0,};
393 	struct net_device *dev;
394 
395 	/* Find device with specified name */
396 	dev = dev_get_by_name(net, dev_name);
397 	if (!dev)
398 		return -ENODEV;
399 	if (tipc_mtu_bad(dev, 0)) {
400 		dev_put(dev);
401 		return -EINVAL;
402 	}
403 	if (dev == net->loopback_dev) {
404 		dev_put(dev);
405 		pr_info("Enabling <%s> not permitted\n", b->name);
406 		return -EINVAL;
407 	}
408 
409 	/* Autoconfigure own node identity if needed */
410 	if (!tipc_own_id(net) && hwaddr_len <= NODE_ID_LEN) {
411 		memcpy(node_id, dev->dev_addr, hwaddr_len);
412 		tipc_net_init(net, node_id, 0);
413 	}
414 	if (!tipc_own_id(net)) {
415 		dev_put(dev);
416 		pr_warn("Failed to obtain node identity\n");
417 		return -EINVAL;
418 	}
419 
420 	/* Associate TIPC bearer with L2 bearer */
421 	rcu_assign_pointer(b->media_ptr, dev);
422 	b->pt.dev = dev;
423 	b->pt.type = htons(ETH_P_TIPC);
424 	b->pt.func = tipc_l2_rcv_msg;
425 	dev_add_pack(&b->pt);
426 	memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
427 	memcpy(b->bcast_addr.value, dev->broadcast, hwaddr_len);
428 	b->bcast_addr.media_id = b->media->type_id;
429 	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
430 	b->mtu = dev->mtu;
431 	b->media->raw2addr(b, &b->addr, (char *)dev->dev_addr);
432 	rcu_assign_pointer(dev->tipc_ptr, b);
433 	return 0;
434 }
435 
436 /* tipc_disable_l2_media - detach TIPC bearer from an L2 interface
437  *
438  * Mark L2 bearer as inactive so that incoming buffers are thrown away
439  */
440 void tipc_disable_l2_media(struct tipc_bearer *b)
441 {
442 	struct net_device *dev;
443 
444 	dev = (struct net_device *)rtnl_dereference(b->media_ptr);
445 	dev_remove_pack(&b->pt);
446 	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
447 	synchronize_net();
448 	dev_put(dev);
449 }
450 
451 /**
452  * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
453  * @skb: the packet to be sent
454  * @b: the bearer through which the packet is to be sent
455  * @dest: peer destination address
456  */
457 int tipc_l2_send_msg(struct net *net, struct sk_buff *skb,
458 		     struct tipc_bearer *b, struct tipc_media_addr *dest)
459 {
460 	struct net_device *dev;
461 	int delta;
462 
463 	dev = (struct net_device *)rcu_dereference(b->media_ptr);
464 	if (!dev)
465 		return 0;
466 
467 	delta = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
468 	if ((delta > 0) && pskb_expand_head(skb, delta, 0, GFP_ATOMIC)) {
469 		kfree_skb(skb);
470 		return 0;
471 	}
472 	skb_reset_network_header(skb);
473 	skb->dev = dev;
474 	skb->protocol = htons(ETH_P_TIPC);
475 	dev_hard_header(skb, dev, ETH_P_TIPC, dest->value,
476 			dev->dev_addr, skb->len);
477 	dev_queue_xmit(skb);
478 	return 0;
479 }
480 
481 bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id)
482 {
483 	bool supp = false;
484 	struct tipc_bearer *b;
485 
486 	rcu_read_lock();
487 	b = bearer_get(net, bearer_id);
488 	if (b)
489 		supp = (b->bcast_addr.broadcast == TIPC_BROADCAST_SUPPORT);
490 	rcu_read_unlock();
491 	return supp;
492 }
493 
494 int tipc_bearer_mtu(struct net *net, u32 bearer_id)
495 {
496 	int mtu = 0;
497 	struct tipc_bearer *b;
498 
499 	rcu_read_lock();
500 	b = rcu_dereference(tipc_net(net)->bearer_list[bearer_id]);
501 	if (b)
502 		mtu = b->mtu;
503 	rcu_read_unlock();
504 	return mtu;
505 }
506 
507 /* tipc_bearer_xmit_skb - sends buffer to destination over bearer
508  */
509 void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
510 			  struct sk_buff *skb,
511 			  struct tipc_media_addr *dest)
512 {
513 	struct tipc_msg *hdr = buf_msg(skb);
514 	struct tipc_bearer *b;
515 
516 	rcu_read_lock();
517 	b = bearer_get(net, bearer_id);
518 	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr)))) {
519 #ifdef CONFIG_TIPC_CRYPTO
520 		tipc_crypto_xmit(net, &skb, b, dest, NULL);
521 		if (skb)
522 #endif
523 			b->media->send_msg(net, skb, b, dest);
524 	} else {
525 		kfree_skb(skb);
526 	}
527 	rcu_read_unlock();
528 }
529 
530 /* tipc_bearer_xmit() -send buffer to destination over bearer
531  */
532 void tipc_bearer_xmit(struct net *net, u32 bearer_id,
533 		      struct sk_buff_head *xmitq,
534 		      struct tipc_media_addr *dst,
535 		      struct tipc_node *__dnode)
536 {
537 	struct tipc_bearer *b;
538 	struct sk_buff *skb, *tmp;
539 
540 	if (skb_queue_empty(xmitq))
541 		return;
542 
543 	rcu_read_lock();
544 	b = bearer_get(net, bearer_id);
545 	if (unlikely(!b))
546 		__skb_queue_purge(xmitq);
547 	skb_queue_walk_safe(xmitq, skb, tmp) {
548 		__skb_dequeue(xmitq);
549 		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb)))) {
550 #ifdef CONFIG_TIPC_CRYPTO
551 			tipc_crypto_xmit(net, &skb, b, dst, __dnode);
552 			if (skb)
553 #endif
554 				b->media->send_msg(net, skb, b, dst);
555 		} else {
556 			kfree_skb(skb);
557 		}
558 	}
559 	rcu_read_unlock();
560 }
561 
562 /* tipc_bearer_bc_xmit() - broadcast buffers to all destinations
563  */
564 void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
565 			 struct sk_buff_head *xmitq)
566 {
567 	struct tipc_net *tn = tipc_net(net);
568 	struct tipc_media_addr *dst;
569 	int net_id = tn->net_id;
570 	struct tipc_bearer *b;
571 	struct sk_buff *skb, *tmp;
572 	struct tipc_msg *hdr;
573 
574 	rcu_read_lock();
575 	b = bearer_get(net, bearer_id);
576 	if (unlikely(!b || !test_bit(0, &b->up)))
577 		__skb_queue_purge(xmitq);
578 	skb_queue_walk_safe(xmitq, skb, tmp) {
579 		hdr = buf_msg(skb);
580 		msg_set_non_seq(hdr, 1);
581 		msg_set_mc_netid(hdr, net_id);
582 		__skb_dequeue(xmitq);
583 		dst = &b->bcast_addr;
584 #ifdef CONFIG_TIPC_CRYPTO
585 		tipc_crypto_xmit(net, &skb, b, dst, NULL);
586 		if (skb)
587 #endif
588 			b->media->send_msg(net, skb, b, dst);
589 	}
590 	rcu_read_unlock();
591 }
592 
593 /**
594  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
595  * @skb: the received message
596  * @dev: the net device that the packet was received on
597  * @pt: the packet_type structure which was used to register this handler
598  * @orig_dev: the original receive net device in case the device is a bond
599  *
600  * Accept only packets explicitly sent to this node, or broadcast packets;
601  * ignores packets sent using interface multicast, and traffic sent to other
602  * nodes (which can happen if interface is running in promiscuous mode).
603  */
604 static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
605 			   struct packet_type *pt, struct net_device *orig_dev)
606 {
607 	struct tipc_bearer *b;
608 
609 	rcu_read_lock();
610 	b = rcu_dereference(dev->tipc_ptr) ?:
611 		rcu_dereference(orig_dev->tipc_ptr);
612 	if (likely(b && test_bit(0, &b->up) &&
613 		   (skb->pkt_type <= PACKET_MULTICAST))) {
614 		skb_mark_not_on_list(skb);
615 		TIPC_SKB_CB(skb)->flags = 0;
616 		tipc_rcv(dev_net(b->pt.dev), skb, b);
617 		rcu_read_unlock();
618 		return NET_RX_SUCCESS;
619 	}
620 	rcu_read_unlock();
621 	kfree_skb(skb);
622 	return NET_RX_DROP;
623 }
624 
625 /**
626  * tipc_l2_device_event - handle device events from network device
627  * @nb: the context of the notification
628  * @evt: the type of event
629  * @ptr: the net device that the event was on
630  *
631  * This function is called by the Ethernet driver in case of link
632  * change event.
633  */
634 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
635 				void *ptr)
636 {
637 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
638 	struct net *net = dev_net(dev);
639 	struct tipc_bearer *b;
640 
641 	b = rtnl_dereference(dev->tipc_ptr);
642 	if (!b)
643 		return NOTIFY_DONE;
644 
645 	trace_tipc_l2_device_event(dev, b, evt);
646 	switch (evt) {
647 	case NETDEV_CHANGE:
648 		if (netif_carrier_ok(dev) && netif_oper_up(dev)) {
649 			test_and_set_bit_lock(0, &b->up);
650 			break;
651 		}
652 		fallthrough;
653 	case NETDEV_GOING_DOWN:
654 		clear_bit_unlock(0, &b->up);
655 		tipc_reset_bearer(net, b);
656 		break;
657 	case NETDEV_UP:
658 		test_and_set_bit_lock(0, &b->up);
659 		break;
660 	case NETDEV_CHANGEMTU:
661 		if (tipc_mtu_bad(dev, 0)) {
662 			bearer_disable(net, b);
663 			break;
664 		}
665 		b->mtu = dev->mtu;
666 		tipc_reset_bearer(net, b);
667 		break;
668 	case NETDEV_CHANGEADDR:
669 		b->media->raw2addr(b, &b->addr,
670 				   (char *)dev->dev_addr);
671 		tipc_reset_bearer(net, b);
672 		break;
673 	case NETDEV_UNREGISTER:
674 	case NETDEV_CHANGENAME:
675 		bearer_disable(net, b);
676 		break;
677 	}
678 	return NOTIFY_OK;
679 }
680 
681 static struct notifier_block notifier = {
682 	.notifier_call  = tipc_l2_device_event,
683 	.priority	= 0,
684 };
685 
686 int tipc_bearer_setup(void)
687 {
688 	return register_netdevice_notifier(&notifier);
689 }
690 
691 void tipc_bearer_cleanup(void)
692 {
693 	unregister_netdevice_notifier(&notifier);
694 }
695 
696 void tipc_bearer_stop(struct net *net)
697 {
698 	struct tipc_net *tn = net_generic(net, tipc_net_id);
699 	struct tipc_bearer *b;
700 	u32 i;
701 
702 	for (i = 0; i < MAX_BEARERS; i++) {
703 		b = rtnl_dereference(tn->bearer_list[i]);
704 		if (b) {
705 			bearer_disable(net, b);
706 			tn->bearer_list[i] = NULL;
707 		}
708 	}
709 }
710 
711 void tipc_clone_to_loopback(struct net *net, struct sk_buff_head *pkts)
712 {
713 	struct net_device *dev = net->loopback_dev;
714 	struct sk_buff *skb, *_skb;
715 	int exp;
716 
717 	skb_queue_walk(pkts, _skb) {
718 		skb = pskb_copy(_skb, GFP_ATOMIC);
719 		if (!skb)
720 			continue;
721 
722 		exp = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
723 		if (exp > 0 && pskb_expand_head(skb, exp, 0, GFP_ATOMIC)) {
724 			kfree_skb(skb);
725 			continue;
726 		}
727 
728 		skb_reset_network_header(skb);
729 		dev_hard_header(skb, dev, ETH_P_TIPC, dev->dev_addr,
730 				dev->dev_addr, skb->len);
731 		skb->dev = dev;
732 		skb->pkt_type = PACKET_HOST;
733 		skb->ip_summed = CHECKSUM_UNNECESSARY;
734 		skb->protocol = eth_type_trans(skb, dev);
735 		netif_rx_ni(skb);
736 	}
737 }
738 
739 static int tipc_loopback_rcv_pkt(struct sk_buff *skb, struct net_device *dev,
740 				 struct packet_type *pt, struct net_device *od)
741 {
742 	consume_skb(skb);
743 	return NET_RX_SUCCESS;
744 }
745 
746 int tipc_attach_loopback(struct net *net)
747 {
748 	struct net_device *dev = net->loopback_dev;
749 	struct tipc_net *tn = tipc_net(net);
750 
751 	if (!dev)
752 		return -ENODEV;
753 
754 	dev_hold(dev);
755 	tn->loopback_pt.dev = dev;
756 	tn->loopback_pt.type = htons(ETH_P_TIPC);
757 	tn->loopback_pt.func = tipc_loopback_rcv_pkt;
758 	dev_add_pack(&tn->loopback_pt);
759 	return 0;
760 }
761 
762 void tipc_detach_loopback(struct net *net)
763 {
764 	struct tipc_net *tn = tipc_net(net);
765 
766 	dev_remove_pack(&tn->loopback_pt);
767 	dev_put(net->loopback_dev);
768 }
769 
770 /* Caller should hold rtnl_lock to protect the bearer */
771 static int __tipc_nl_add_bearer(struct tipc_nl_msg *msg,
772 				struct tipc_bearer *bearer, int nlflags)
773 {
774 	void *hdr;
775 	struct nlattr *attrs;
776 	struct nlattr *prop;
777 
778 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
779 			  nlflags, TIPC_NL_BEARER_GET);
780 	if (!hdr)
781 		return -EMSGSIZE;
782 
783 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER);
784 	if (!attrs)
785 		goto msg_full;
786 
787 	if (nla_put_string(msg->skb, TIPC_NLA_BEARER_NAME, bearer->name))
788 		goto attr_msg_full;
789 
790 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_PROP);
791 	if (!prop)
792 		goto prop_msg_full;
793 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, bearer->priority))
794 		goto prop_msg_full;
795 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, bearer->tolerance))
796 		goto prop_msg_full;
797 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bearer->max_win))
798 		goto prop_msg_full;
799 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP)
800 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, bearer->mtu))
801 			goto prop_msg_full;
802 
803 	nla_nest_end(msg->skb, prop);
804 
805 #ifdef CONFIG_TIPC_MEDIA_UDP
806 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP) {
807 		if (tipc_udp_nl_add_bearer_data(msg, bearer))
808 			goto attr_msg_full;
809 	}
810 #endif
811 
812 	nla_nest_end(msg->skb, attrs);
813 	genlmsg_end(msg->skb, hdr);
814 
815 	return 0;
816 
817 prop_msg_full:
818 	nla_nest_cancel(msg->skb, prop);
819 attr_msg_full:
820 	nla_nest_cancel(msg->skb, attrs);
821 msg_full:
822 	genlmsg_cancel(msg->skb, hdr);
823 
824 	return -EMSGSIZE;
825 }
826 
827 int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb)
828 {
829 	int err;
830 	int i = cb->args[0];
831 	struct tipc_bearer *bearer;
832 	struct tipc_nl_msg msg;
833 	struct net *net = sock_net(skb->sk);
834 	struct tipc_net *tn = net_generic(net, tipc_net_id);
835 
836 	if (i == MAX_BEARERS)
837 		return 0;
838 
839 	msg.skb = skb;
840 	msg.portid = NETLINK_CB(cb->skb).portid;
841 	msg.seq = cb->nlh->nlmsg_seq;
842 
843 	rtnl_lock();
844 	for (i = 0; i < MAX_BEARERS; i++) {
845 		bearer = rtnl_dereference(tn->bearer_list[i]);
846 		if (!bearer)
847 			continue;
848 
849 		err = __tipc_nl_add_bearer(&msg, bearer, NLM_F_MULTI);
850 		if (err)
851 			break;
852 	}
853 	rtnl_unlock();
854 
855 	cb->args[0] = i;
856 	return skb->len;
857 }
858 
859 int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info)
860 {
861 	int err;
862 	char *name;
863 	struct sk_buff *rep;
864 	struct tipc_bearer *bearer;
865 	struct tipc_nl_msg msg;
866 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
867 	struct net *net = genl_info_net(info);
868 
869 	if (!info->attrs[TIPC_NLA_BEARER])
870 		return -EINVAL;
871 
872 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
873 					  info->attrs[TIPC_NLA_BEARER],
874 					  tipc_nl_bearer_policy, info->extack);
875 	if (err)
876 		return err;
877 
878 	if (!attrs[TIPC_NLA_BEARER_NAME])
879 		return -EINVAL;
880 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
881 
882 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
883 	if (!rep)
884 		return -ENOMEM;
885 
886 	msg.skb = rep;
887 	msg.portid = info->snd_portid;
888 	msg.seq = info->snd_seq;
889 
890 	rtnl_lock();
891 	bearer = tipc_bearer_find(net, name);
892 	if (!bearer) {
893 		err = -EINVAL;
894 		goto err_out;
895 	}
896 
897 	err = __tipc_nl_add_bearer(&msg, bearer, 0);
898 	if (err)
899 		goto err_out;
900 	rtnl_unlock();
901 
902 	return genlmsg_reply(rep, info);
903 err_out:
904 	rtnl_unlock();
905 	nlmsg_free(rep);
906 
907 	return err;
908 }
909 
910 int __tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
911 {
912 	int err;
913 	char *name;
914 	struct tipc_bearer *bearer;
915 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
916 	struct net *net = sock_net(skb->sk);
917 
918 	if (!info->attrs[TIPC_NLA_BEARER])
919 		return -EINVAL;
920 
921 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
922 					  info->attrs[TIPC_NLA_BEARER],
923 					  tipc_nl_bearer_policy, info->extack);
924 	if (err)
925 		return err;
926 
927 	if (!attrs[TIPC_NLA_BEARER_NAME])
928 		return -EINVAL;
929 
930 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
931 
932 	bearer = tipc_bearer_find(net, name);
933 	if (!bearer)
934 		return -EINVAL;
935 
936 	bearer_disable(net, bearer);
937 
938 	return 0;
939 }
940 
941 int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
942 {
943 	int err;
944 
945 	rtnl_lock();
946 	err = __tipc_nl_bearer_disable(skb, info);
947 	rtnl_unlock();
948 
949 	return err;
950 }
951 
952 int __tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
953 {
954 	int err;
955 	char *bearer;
956 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
957 	struct net *net = sock_net(skb->sk);
958 	u32 domain = 0;
959 	u32 prio;
960 
961 	prio = TIPC_MEDIA_LINK_PRI;
962 
963 	if (!info->attrs[TIPC_NLA_BEARER])
964 		return -EINVAL;
965 
966 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
967 					  info->attrs[TIPC_NLA_BEARER],
968 					  tipc_nl_bearer_policy, info->extack);
969 	if (err)
970 		return err;
971 
972 	if (!attrs[TIPC_NLA_BEARER_NAME])
973 		return -EINVAL;
974 
975 	bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
976 
977 	if (attrs[TIPC_NLA_BEARER_DOMAIN])
978 		domain = nla_get_u32(attrs[TIPC_NLA_BEARER_DOMAIN]);
979 
980 	if (attrs[TIPC_NLA_BEARER_PROP]) {
981 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
982 
983 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
984 					      props);
985 		if (err)
986 			return err;
987 
988 		if (props[TIPC_NLA_PROP_PRIO])
989 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
990 	}
991 
992 	return tipc_enable_bearer(net, bearer, domain, prio, attrs);
993 }
994 
995 int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
996 {
997 	int err;
998 
999 	rtnl_lock();
1000 	err = __tipc_nl_bearer_enable(skb, info);
1001 	rtnl_unlock();
1002 
1003 	return err;
1004 }
1005 
1006 int tipc_nl_bearer_add(struct sk_buff *skb, struct genl_info *info)
1007 {
1008 	int err;
1009 	char *name;
1010 	struct tipc_bearer *b;
1011 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1012 	struct net *net = sock_net(skb->sk);
1013 
1014 	if (!info->attrs[TIPC_NLA_BEARER])
1015 		return -EINVAL;
1016 
1017 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1018 					  info->attrs[TIPC_NLA_BEARER],
1019 					  tipc_nl_bearer_policy, info->extack);
1020 	if (err)
1021 		return err;
1022 
1023 	if (!attrs[TIPC_NLA_BEARER_NAME])
1024 		return -EINVAL;
1025 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1026 
1027 	rtnl_lock();
1028 	b = tipc_bearer_find(net, name);
1029 	if (!b) {
1030 		rtnl_unlock();
1031 		return -EINVAL;
1032 	}
1033 
1034 #ifdef CONFIG_TIPC_MEDIA_UDP
1035 	if (attrs[TIPC_NLA_BEARER_UDP_OPTS]) {
1036 		err = tipc_udp_nl_bearer_add(b,
1037 					     attrs[TIPC_NLA_BEARER_UDP_OPTS]);
1038 		if (err) {
1039 			rtnl_unlock();
1040 			return err;
1041 		}
1042 	}
1043 #endif
1044 	rtnl_unlock();
1045 
1046 	return 0;
1047 }
1048 
1049 int __tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1050 {
1051 	struct tipc_bearer *b;
1052 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1053 	struct net *net = sock_net(skb->sk);
1054 	char *name;
1055 	int err;
1056 
1057 	if (!info->attrs[TIPC_NLA_BEARER])
1058 		return -EINVAL;
1059 
1060 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1061 					  info->attrs[TIPC_NLA_BEARER],
1062 					  tipc_nl_bearer_policy, info->extack);
1063 	if (err)
1064 		return err;
1065 
1066 	if (!attrs[TIPC_NLA_BEARER_NAME])
1067 		return -EINVAL;
1068 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1069 
1070 	b = tipc_bearer_find(net, name);
1071 	if (!b)
1072 		return -EINVAL;
1073 
1074 	if (attrs[TIPC_NLA_BEARER_PROP]) {
1075 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1076 
1077 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1078 					      props);
1079 		if (err)
1080 			return err;
1081 
1082 		if (props[TIPC_NLA_PROP_TOL]) {
1083 			b->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1084 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_TOL);
1085 		}
1086 		if (props[TIPC_NLA_PROP_PRIO])
1087 			b->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1088 		if (props[TIPC_NLA_PROP_WIN])
1089 			b->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1090 		if (props[TIPC_NLA_PROP_MTU]) {
1091 			if (b->media->type_id != TIPC_MEDIA_TYPE_UDP)
1092 				return -EINVAL;
1093 #ifdef CONFIG_TIPC_MEDIA_UDP
1094 			if (tipc_udp_mtu_bad(nla_get_u32
1095 					     (props[TIPC_NLA_PROP_MTU])))
1096 				return -EINVAL;
1097 			b->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1098 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_MTU);
1099 #endif
1100 		}
1101 	}
1102 
1103 	return 0;
1104 }
1105 
1106 int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1107 {
1108 	int err;
1109 
1110 	rtnl_lock();
1111 	err = __tipc_nl_bearer_set(skb, info);
1112 	rtnl_unlock();
1113 
1114 	return err;
1115 }
1116 
1117 static int __tipc_nl_add_media(struct tipc_nl_msg *msg,
1118 			       struct tipc_media *media, int nlflags)
1119 {
1120 	void *hdr;
1121 	struct nlattr *attrs;
1122 	struct nlattr *prop;
1123 
1124 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1125 			  nlflags, TIPC_NL_MEDIA_GET);
1126 	if (!hdr)
1127 		return -EMSGSIZE;
1128 
1129 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA);
1130 	if (!attrs)
1131 		goto msg_full;
1132 
1133 	if (nla_put_string(msg->skb, TIPC_NLA_MEDIA_NAME, media->name))
1134 		goto attr_msg_full;
1135 
1136 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA_PROP);
1137 	if (!prop)
1138 		goto prop_msg_full;
1139 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, media->priority))
1140 		goto prop_msg_full;
1141 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, media->tolerance))
1142 		goto prop_msg_full;
1143 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, media->max_win))
1144 		goto prop_msg_full;
1145 	if (media->type_id == TIPC_MEDIA_TYPE_UDP)
1146 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, media->mtu))
1147 			goto prop_msg_full;
1148 
1149 	nla_nest_end(msg->skb, prop);
1150 	nla_nest_end(msg->skb, attrs);
1151 	genlmsg_end(msg->skb, hdr);
1152 
1153 	return 0;
1154 
1155 prop_msg_full:
1156 	nla_nest_cancel(msg->skb, prop);
1157 attr_msg_full:
1158 	nla_nest_cancel(msg->skb, attrs);
1159 msg_full:
1160 	genlmsg_cancel(msg->skb, hdr);
1161 
1162 	return -EMSGSIZE;
1163 }
1164 
1165 int tipc_nl_media_dump(struct sk_buff *skb, struct netlink_callback *cb)
1166 {
1167 	int err;
1168 	int i = cb->args[0];
1169 	struct tipc_nl_msg msg;
1170 
1171 	if (i == MAX_MEDIA)
1172 		return 0;
1173 
1174 	msg.skb = skb;
1175 	msg.portid = NETLINK_CB(cb->skb).portid;
1176 	msg.seq = cb->nlh->nlmsg_seq;
1177 
1178 	rtnl_lock();
1179 	for (; media_info_array[i] != NULL; i++) {
1180 		err = __tipc_nl_add_media(&msg, media_info_array[i],
1181 					  NLM_F_MULTI);
1182 		if (err)
1183 			break;
1184 	}
1185 	rtnl_unlock();
1186 
1187 	cb->args[0] = i;
1188 	return skb->len;
1189 }
1190 
1191 int tipc_nl_media_get(struct sk_buff *skb, struct genl_info *info)
1192 {
1193 	int err;
1194 	char *name;
1195 	struct tipc_nl_msg msg;
1196 	struct tipc_media *media;
1197 	struct sk_buff *rep;
1198 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1199 
1200 	if (!info->attrs[TIPC_NLA_MEDIA])
1201 		return -EINVAL;
1202 
1203 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1204 					  info->attrs[TIPC_NLA_MEDIA],
1205 					  tipc_nl_media_policy, info->extack);
1206 	if (err)
1207 		return err;
1208 
1209 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1210 		return -EINVAL;
1211 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1212 
1213 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1214 	if (!rep)
1215 		return -ENOMEM;
1216 
1217 	msg.skb = rep;
1218 	msg.portid = info->snd_portid;
1219 	msg.seq = info->snd_seq;
1220 
1221 	rtnl_lock();
1222 	media = tipc_media_find(name);
1223 	if (!media) {
1224 		err = -EINVAL;
1225 		goto err_out;
1226 	}
1227 
1228 	err = __tipc_nl_add_media(&msg, media, 0);
1229 	if (err)
1230 		goto err_out;
1231 	rtnl_unlock();
1232 
1233 	return genlmsg_reply(rep, info);
1234 err_out:
1235 	rtnl_unlock();
1236 	nlmsg_free(rep);
1237 
1238 	return err;
1239 }
1240 
1241 int __tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1242 {
1243 	int err;
1244 	char *name;
1245 	struct tipc_media *m;
1246 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1247 
1248 	if (!info->attrs[TIPC_NLA_MEDIA])
1249 		return -EINVAL;
1250 
1251 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1252 					  info->attrs[TIPC_NLA_MEDIA],
1253 					  tipc_nl_media_policy, info->extack);
1254 
1255 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1256 		return -EINVAL;
1257 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1258 
1259 	m = tipc_media_find(name);
1260 	if (!m)
1261 		return -EINVAL;
1262 
1263 	if (attrs[TIPC_NLA_MEDIA_PROP]) {
1264 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1265 
1266 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_MEDIA_PROP],
1267 					      props);
1268 		if (err)
1269 			return err;
1270 
1271 		if (props[TIPC_NLA_PROP_TOL])
1272 			m->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1273 		if (props[TIPC_NLA_PROP_PRIO])
1274 			m->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1275 		if (props[TIPC_NLA_PROP_WIN])
1276 			m->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1277 		if (props[TIPC_NLA_PROP_MTU]) {
1278 			if (m->type_id != TIPC_MEDIA_TYPE_UDP)
1279 				return -EINVAL;
1280 #ifdef CONFIG_TIPC_MEDIA_UDP
1281 			if (tipc_udp_mtu_bad(nla_get_u32
1282 					     (props[TIPC_NLA_PROP_MTU])))
1283 				return -EINVAL;
1284 			m->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1285 #endif
1286 		}
1287 	}
1288 
1289 	return 0;
1290 }
1291 
1292 int tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1293 {
1294 	int err;
1295 
1296 	rtnl_lock();
1297 	err = __tipc_nl_media_set(skb, info);
1298 	rtnl_unlock();
1299 
1300 	return err;
1301 }
1302