xref: /linux/net/tipc/bearer.c (revision fbf46565c67c626849c7ce2a326972d3008d2a91)
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  * @name: name to locate
76  */
77 struct tipc_media *tipc_media_find(const char *name)
78 {
79 	u32 i;
80 
81 	for (i = 0; media_info_array[i] != NULL; i++) {
82 		if (!strcmp(media_info_array[i]->name, name))
83 			break;
84 	}
85 	return media_info_array[i];
86 }
87 
88 /**
89  * media_find_id - locates specified media object by type identifier
90  * @type: type identifier to locate
91  */
92 static struct tipc_media *media_find_id(u8 type)
93 {
94 	u32 i;
95 
96 	for (i = 0; media_info_array[i] != NULL; i++) {
97 		if (media_info_array[i]->type_id == type)
98 			break;
99 	}
100 	return media_info_array[i];
101 }
102 
103 /**
104  * tipc_media_addr_printf - record media address in print buffer
105  * @buf: output buffer
106  * @len: output buffer size remaining
107  * @a: input media address
108  */
109 int tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a)
110 {
111 	char addr_str[MAX_ADDR_STR];
112 	struct tipc_media *m;
113 	int ret;
114 
115 	m = media_find_id(a->media_id);
116 
117 	if (m && !m->addr2str(a, addr_str, sizeof(addr_str)))
118 		ret = scnprintf(buf, len, "%s(%s)", m->name, addr_str);
119 	else {
120 		u32 i;
121 
122 		ret = scnprintf(buf, len, "UNKNOWN(%u)", a->media_id);
123 		for (i = 0; i < sizeof(a->value); i++)
124 			ret += scnprintf(buf + ret, len - ret,
125 					    "-%x", a->value[i]);
126 	}
127 	return ret;
128 }
129 
130 /**
131  * bearer_name_validate - validate & (optionally) deconstruct bearer name
132  * @name: ptr to bearer name string
133  * @name_parts: ptr to area for bearer name components (or NULL if not needed)
134  *
135  * Return: 1 if bearer name is valid, otherwise 0.
136  */
137 static int bearer_name_validate(const char *name,
138 				struct tipc_bearer_names *name_parts)
139 {
140 	char name_copy[TIPC_MAX_BEARER_NAME];
141 	char *media_name;
142 	char *if_name;
143 	u32 media_len;
144 	u32 if_len;
145 
146 	/* copy bearer name & ensure length is OK */
147 	if (strscpy(name_copy, name, TIPC_MAX_BEARER_NAME) < 0)
148 		return 0;
149 
150 	/* ensure all component parts of bearer name are present */
151 	media_name = name_copy;
152 	if_name = strchr(media_name, ':');
153 	if (if_name == NULL)
154 		return 0;
155 	*(if_name++) = 0;
156 	media_len = if_name - media_name;
157 	if_len = strlen(if_name) + 1;
158 
159 	/* validate component parts of bearer name */
160 	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
161 	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
162 		return 0;
163 
164 	/* return bearer name components, if necessary */
165 	if (name_parts) {
166 		strcpy(name_parts->media_name, media_name);
167 		strcpy(name_parts->if_name, if_name);
168 	}
169 	return 1;
170 }
171 
172 /**
173  * tipc_bearer_find - locates bearer object with matching bearer name
174  * @net: the applicable net namespace
175  * @name: bearer name to locate
176  */
177 struct tipc_bearer *tipc_bearer_find(struct net *net, const char *name)
178 {
179 	struct tipc_net *tn = net_generic(net, tipc_net_id);
180 	struct tipc_bearer *b;
181 	u32 i;
182 
183 	for (i = 0; i < MAX_BEARERS; i++) {
184 		b = rtnl_dereference(tn->bearer_list[i]);
185 		if (b && (!strcmp(b->name, name)))
186 			return b;
187 	}
188 	return NULL;
189 }
190 
191 /*     tipc_bearer_get_name - get the bearer name from its id.
192  *     @net: network namespace
193  *     @name: a pointer to the buffer where the name will be stored.
194  *     @bearer_id: the id to get the name from.
195  */
196 int tipc_bearer_get_name(struct net *net, char *name, u32 bearer_id)
197 {
198 	struct tipc_net *tn = tipc_net(net);
199 	struct tipc_bearer *b;
200 
201 	if (bearer_id >= MAX_BEARERS)
202 		return -EINVAL;
203 
204 	b = rtnl_dereference(tn->bearer_list[bearer_id]);
205 	if (!b)
206 		return -EINVAL;
207 
208 	strcpy(name, b->name);
209 	return 0;
210 }
211 
212 void tipc_bearer_add_dest(struct net *net, u32 bearer_id, u32 dest)
213 {
214 	struct tipc_net *tn = net_generic(net, tipc_net_id);
215 	struct tipc_bearer *b;
216 
217 	rcu_read_lock();
218 	b = rcu_dereference(tn->bearer_list[bearer_id]);
219 	if (b)
220 		tipc_disc_add_dest(b->disc);
221 	rcu_read_unlock();
222 }
223 
224 void tipc_bearer_remove_dest(struct net *net, u32 bearer_id, u32 dest)
225 {
226 	struct tipc_net *tn = net_generic(net, tipc_net_id);
227 	struct tipc_bearer *b;
228 
229 	rcu_read_lock();
230 	b = rcu_dereference(tn->bearer_list[bearer_id]);
231 	if (b)
232 		tipc_disc_remove_dest(b->disc);
233 	rcu_read_unlock();
234 }
235 
236 /**
237  * tipc_enable_bearer - enable bearer with the given name
238  * @net: the applicable net namespace
239  * @name: bearer name to enable
240  * @disc_domain: bearer domain
241  * @prio: bearer priority
242  * @attr: nlattr array
243  * @extack: netlink extended ack
244  */
245 static int tipc_enable_bearer(struct net *net, const char *name,
246 			      u32 disc_domain, u32 prio,
247 			      struct nlattr *attr[],
248 			      struct netlink_ext_ack *extack)
249 {
250 	struct tipc_net *tn = tipc_net(net);
251 	struct tipc_bearer_names b_names;
252 	int with_this_prio = 1;
253 	struct tipc_bearer *b;
254 	struct tipc_media *m;
255 	struct sk_buff *skb;
256 	int bearer_id = 0;
257 	int res = -EINVAL;
258 	char *errstr = "";
259 	u32 i;
260 
261 	if (!bearer_name_validate(name, &b_names)) {
262 		NL_SET_ERR_MSG(extack, "Illegal name");
263 		return res;
264 	}
265 
266 	if (prio > TIPC_MAX_LINK_PRI && prio != TIPC_MEDIA_LINK_PRI) {
267 		errstr = "illegal priority";
268 		NL_SET_ERR_MSG(extack, "Illegal priority");
269 		goto rejected;
270 	}
271 
272 	m = tipc_media_find(b_names.media_name);
273 	if (!m) {
274 		errstr = "media not registered";
275 		NL_SET_ERR_MSG(extack, "Media not registered");
276 		goto rejected;
277 	}
278 
279 	if (prio == TIPC_MEDIA_LINK_PRI)
280 		prio = m->priority;
281 
282 	/* Check new bearer vs existing ones and find free bearer id if any */
283 	bearer_id = MAX_BEARERS;
284 	i = MAX_BEARERS;
285 	while (i-- != 0) {
286 		b = rtnl_dereference(tn->bearer_list[i]);
287 		if (!b) {
288 			bearer_id = i;
289 			continue;
290 		}
291 		if (!strcmp(name, b->name)) {
292 			errstr = "already enabled";
293 			NL_SET_ERR_MSG(extack, "Already enabled");
294 			goto rejected;
295 		}
296 
297 		if (b->priority == prio &&
298 		    (++with_this_prio > 2)) {
299 			pr_warn("Bearer <%s>: already 2 bearers with priority %u\n",
300 				name, prio);
301 
302 			if (prio == TIPC_MIN_LINK_PRI) {
303 				errstr = "cannot adjust to lower";
304 				NL_SET_ERR_MSG(extack, "Cannot adjust to lower");
305 				goto rejected;
306 			}
307 
308 			pr_warn("Bearer <%s>: trying with adjusted priority\n",
309 				name);
310 			prio--;
311 			bearer_id = MAX_BEARERS;
312 			i = MAX_BEARERS;
313 			with_this_prio = 1;
314 		}
315 	}
316 
317 	if (bearer_id >= MAX_BEARERS) {
318 		errstr = "max 3 bearers permitted";
319 		NL_SET_ERR_MSG(extack, "Max 3 bearers permitted");
320 		goto rejected;
321 	}
322 
323 	b = kzalloc(sizeof(*b), GFP_ATOMIC);
324 	if (!b)
325 		return -ENOMEM;
326 
327 	strcpy(b->name, name);
328 	b->media = m;
329 	res = m->enable_media(net, b, attr);
330 	if (res) {
331 		kfree(b);
332 		errstr = "failed to enable media";
333 		NL_SET_ERR_MSG(extack, "Failed to enable media");
334 		goto rejected;
335 	}
336 
337 	b->identity = bearer_id;
338 	b->tolerance = m->tolerance;
339 	b->min_win = m->min_win;
340 	b->max_win = m->max_win;
341 	b->domain = disc_domain;
342 	b->net_plane = bearer_id + 'A';
343 	b->priority = prio;
344 	refcount_set(&b->refcnt, 1);
345 
346 	res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
347 	if (res) {
348 		bearer_disable(net, b);
349 		errstr = "failed to create discoverer";
350 		NL_SET_ERR_MSG(extack, "Failed to create discoverer");
351 		goto rejected;
352 	}
353 
354 	/* Create monitoring data before accepting activate messages */
355 	if (tipc_mon_create(net, bearer_id)) {
356 		bearer_disable(net, b);
357 		kfree_skb(skb);
358 		return -ENOMEM;
359 	}
360 
361 	test_and_set_bit_lock(0, &b->up);
362 	rcu_assign_pointer(tn->bearer_list[bearer_id], b);
363 	if (skb)
364 		tipc_bearer_xmit_skb(net, bearer_id, skb, &b->bcast_addr);
365 
366 	pr_info("Enabled bearer <%s>, priority %u\n", name, prio);
367 
368 	return res;
369 rejected:
370 	pr_warn("Enabling of bearer <%s> rejected, %s\n", name, errstr);
371 	return res;
372 }
373 
374 /**
375  * tipc_reset_bearer - Reset all links established over this bearer
376  * @net: the applicable net namespace
377  * @b: the target bearer
378  */
379 static int tipc_reset_bearer(struct net *net, struct tipc_bearer *b)
380 {
381 	pr_info("Resetting bearer <%s>\n", b->name);
382 	tipc_node_delete_links(net, b->identity);
383 	tipc_disc_reset(net, b);
384 	return 0;
385 }
386 
387 bool tipc_bearer_hold(struct tipc_bearer *b)
388 {
389 	return (b && refcount_inc_not_zero(&b->refcnt));
390 }
391 
392 void tipc_bearer_put(struct tipc_bearer *b)
393 {
394 	if (b && refcount_dec_and_test(&b->refcnt))
395 		kfree_rcu(b, rcu);
396 }
397 
398 /**
399  * bearer_disable - disable this bearer
400  * @net: the applicable net namespace
401  * @b: the bearer to disable
402  *
403  * Note: This routine assumes caller holds RTNL lock.
404  */
405 static void bearer_disable(struct net *net, struct tipc_bearer *b)
406 {
407 	struct tipc_net *tn = tipc_net(net);
408 	int bearer_id = b->identity;
409 
410 	pr_info("Disabling bearer <%s>\n", b->name);
411 	clear_bit_unlock(0, &b->up);
412 	tipc_node_delete_links(net, bearer_id);
413 	b->media->disable_media(b);
414 	RCU_INIT_POINTER(b->media_ptr, NULL);
415 	if (b->disc)
416 		tipc_disc_delete(b->disc);
417 	RCU_INIT_POINTER(tn->bearer_list[bearer_id], NULL);
418 	tipc_bearer_put(b);
419 	tipc_mon_delete(net, bearer_id);
420 }
421 
422 int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
423 			 struct nlattr *attr[])
424 {
425 	char *dev_name = strchr((const char *)b->name, ':') + 1;
426 	int hwaddr_len = b->media->hwaddr_len;
427 	u8 node_id[NODE_ID_LEN] = {0,};
428 	struct net_device *dev;
429 
430 	/* Find device with specified name */
431 	dev = dev_get_by_name(net, dev_name);
432 	if (!dev)
433 		return -ENODEV;
434 	if (tipc_mtu_bad(dev, 0)) {
435 		dev_put(dev);
436 		return -EINVAL;
437 	}
438 	if (dev == net->loopback_dev) {
439 		dev_put(dev);
440 		pr_info("Enabling <%s> not permitted\n", b->name);
441 		return -EINVAL;
442 	}
443 
444 	/* Autoconfigure own node identity if needed */
445 	if (!tipc_own_id(net) && hwaddr_len <= NODE_ID_LEN) {
446 		memcpy(node_id, dev->dev_addr, hwaddr_len);
447 		tipc_net_init(net, node_id, 0);
448 	}
449 	if (!tipc_own_id(net)) {
450 		dev_put(dev);
451 		pr_warn("Failed to obtain node identity\n");
452 		return -EINVAL;
453 	}
454 
455 	/* Associate TIPC bearer with L2 bearer */
456 	rcu_assign_pointer(b->media_ptr, dev);
457 	b->pt.dev = dev;
458 	b->pt.type = htons(ETH_P_TIPC);
459 	b->pt.func = tipc_l2_rcv_msg;
460 	dev_add_pack(&b->pt);
461 	memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
462 	memcpy(b->bcast_addr.value, dev->broadcast, hwaddr_len);
463 	b->bcast_addr.media_id = b->media->type_id;
464 	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
465 	b->mtu = dev->mtu;
466 	b->media->raw2addr(b, &b->addr, (const char *)dev->dev_addr);
467 	rcu_assign_pointer(dev->tipc_ptr, b);
468 	return 0;
469 }
470 
471 /* tipc_disable_l2_media - detach TIPC bearer from an L2 interface
472  * @b: the target bearer
473  *
474  * Mark L2 bearer as inactive so that incoming buffers are thrown away
475  */
476 void tipc_disable_l2_media(struct tipc_bearer *b)
477 {
478 	struct net_device *dev;
479 
480 	dev = (struct net_device *)rtnl_dereference(b->media_ptr);
481 	dev_remove_pack(&b->pt);
482 	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
483 	synchronize_net();
484 	dev_put(dev);
485 }
486 
487 /**
488  * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
489  * @net: the associated network namespace
490  * @skb: the packet to be sent
491  * @b: the bearer through which the packet is to be sent
492  * @dest: peer destination address
493  */
494 int tipc_l2_send_msg(struct net *net, struct sk_buff *skb,
495 		     struct tipc_bearer *b, struct tipc_media_addr *dest)
496 {
497 	struct net_device *dev;
498 	int delta;
499 
500 	dev = (struct net_device *)rcu_dereference(b->media_ptr);
501 	if (!dev)
502 		return 0;
503 
504 	delta = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
505 	if ((delta > 0) && pskb_expand_head(skb, delta, 0, GFP_ATOMIC)) {
506 		kfree_skb(skb);
507 		return 0;
508 	}
509 	skb_reset_network_header(skb);
510 	skb->dev = dev;
511 	skb->protocol = htons(ETH_P_TIPC);
512 	dev_hard_header(skb, dev, ETH_P_TIPC, dest->value,
513 			dev->dev_addr, skb->len);
514 	dev_queue_xmit(skb);
515 	return 0;
516 }
517 
518 bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id)
519 {
520 	bool supp = false;
521 	struct tipc_bearer *b;
522 
523 	rcu_read_lock();
524 	b = bearer_get(net, bearer_id);
525 	if (b)
526 		supp = (b->bcast_addr.broadcast == TIPC_BROADCAST_SUPPORT);
527 	rcu_read_unlock();
528 	return supp;
529 }
530 
531 int tipc_bearer_mtu(struct net *net, u32 bearer_id)
532 {
533 	int mtu = 0;
534 	struct tipc_bearer *b;
535 
536 	rcu_read_lock();
537 	b = rcu_dereference(tipc_net(net)->bearer_list[bearer_id]);
538 	if (b)
539 		mtu = b->mtu;
540 	rcu_read_unlock();
541 	return mtu;
542 }
543 
544 /* tipc_bearer_xmit_skb - sends buffer to destination over bearer
545  */
546 void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
547 			  struct sk_buff *skb,
548 			  struct tipc_media_addr *dest)
549 {
550 	struct tipc_msg *hdr = buf_msg(skb);
551 	struct tipc_bearer *b;
552 
553 	rcu_read_lock();
554 	b = bearer_get(net, bearer_id);
555 	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr)))) {
556 #ifdef CONFIG_TIPC_CRYPTO
557 		tipc_crypto_xmit(net, &skb, b, dest, NULL);
558 		if (skb)
559 #endif
560 			b->media->send_msg(net, skb, b, dest);
561 	} else {
562 		kfree_skb(skb);
563 	}
564 	rcu_read_unlock();
565 }
566 
567 /* tipc_bearer_xmit() -send buffer to destination over bearer
568  */
569 void tipc_bearer_xmit(struct net *net, u32 bearer_id,
570 		      struct sk_buff_head *xmitq,
571 		      struct tipc_media_addr *dst,
572 		      struct tipc_node *__dnode)
573 {
574 	struct tipc_bearer *b;
575 	struct sk_buff *skb, *tmp;
576 
577 	if (skb_queue_empty(xmitq))
578 		return;
579 
580 	rcu_read_lock();
581 	b = bearer_get(net, bearer_id);
582 	if (unlikely(!b))
583 		__skb_queue_purge(xmitq);
584 	skb_queue_walk_safe(xmitq, skb, tmp) {
585 		__skb_dequeue(xmitq);
586 		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb)))) {
587 #ifdef CONFIG_TIPC_CRYPTO
588 			tipc_crypto_xmit(net, &skb, b, dst, __dnode);
589 			if (skb)
590 #endif
591 				b->media->send_msg(net, skb, b, dst);
592 		} else {
593 			kfree_skb(skb);
594 		}
595 	}
596 	rcu_read_unlock();
597 }
598 
599 /* tipc_bearer_bc_xmit() - broadcast buffers to all destinations
600  */
601 void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
602 			 struct sk_buff_head *xmitq)
603 {
604 	struct tipc_net *tn = tipc_net(net);
605 	struct tipc_media_addr *dst;
606 	int net_id = tn->net_id;
607 	struct tipc_bearer *b;
608 	struct sk_buff *skb, *tmp;
609 	struct tipc_msg *hdr;
610 
611 	rcu_read_lock();
612 	b = bearer_get(net, bearer_id);
613 	if (unlikely(!b || !test_bit(0, &b->up)))
614 		__skb_queue_purge(xmitq);
615 	skb_queue_walk_safe(xmitq, skb, tmp) {
616 		hdr = buf_msg(skb);
617 		msg_set_non_seq(hdr, 1);
618 		msg_set_mc_netid(hdr, net_id);
619 		__skb_dequeue(xmitq);
620 		dst = &b->bcast_addr;
621 #ifdef CONFIG_TIPC_CRYPTO
622 		tipc_crypto_xmit(net, &skb, b, dst, NULL);
623 		if (skb)
624 #endif
625 			b->media->send_msg(net, skb, b, dst);
626 	}
627 	rcu_read_unlock();
628 }
629 
630 /**
631  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
632  * @skb: the received message
633  * @dev: the net device that the packet was received on
634  * @pt: the packet_type structure which was used to register this handler
635  * @orig_dev: the original receive net device in case the device is a bond
636  *
637  * Accept only packets explicitly sent to this node, or broadcast packets;
638  * ignores packets sent using interface multicast, and traffic sent to other
639  * nodes (which can happen if interface is running in promiscuous mode).
640  */
641 static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
642 			   struct packet_type *pt, struct net_device *orig_dev)
643 {
644 	struct tipc_bearer *b;
645 
646 	rcu_read_lock();
647 	b = rcu_dereference(dev->tipc_ptr) ?:
648 		rcu_dereference(orig_dev->tipc_ptr);
649 	if (likely(b && test_bit(0, &b->up) &&
650 		   (skb->pkt_type <= PACKET_MULTICAST))) {
651 		skb_mark_not_on_list(skb);
652 		TIPC_SKB_CB(skb)->flags = 0;
653 		tipc_rcv(dev_net(b->pt.dev), skb, b);
654 		rcu_read_unlock();
655 		return NET_RX_SUCCESS;
656 	}
657 	rcu_read_unlock();
658 	kfree_skb(skb);
659 	return NET_RX_DROP;
660 }
661 
662 /**
663  * tipc_l2_device_event - handle device events from network device
664  * @nb: the context of the notification
665  * @evt: the type of event
666  * @ptr: the net device that the event was on
667  *
668  * This function is called by the Ethernet driver in case of link
669  * change event.
670  */
671 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
672 				void *ptr)
673 {
674 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
675 	struct net *net = dev_net(dev);
676 	struct tipc_bearer *b;
677 
678 	b = rtnl_dereference(dev->tipc_ptr);
679 	if (!b)
680 		return NOTIFY_DONE;
681 
682 	trace_tipc_l2_device_event(dev, b, evt);
683 	switch (evt) {
684 	case NETDEV_CHANGE:
685 		if (netif_carrier_ok(dev) && netif_oper_up(dev)) {
686 			test_and_set_bit_lock(0, &b->up);
687 			break;
688 		}
689 		fallthrough;
690 	case NETDEV_GOING_DOWN:
691 		clear_bit_unlock(0, &b->up);
692 		tipc_reset_bearer(net, b);
693 		break;
694 	case NETDEV_UP:
695 		test_and_set_bit_lock(0, &b->up);
696 		break;
697 	case NETDEV_CHANGEMTU:
698 		if (tipc_mtu_bad(dev, 0)) {
699 			bearer_disable(net, b);
700 			break;
701 		}
702 		b->mtu = dev->mtu;
703 		tipc_reset_bearer(net, b);
704 		break;
705 	case NETDEV_CHANGEADDR:
706 		b->media->raw2addr(b, &b->addr,
707 				   (const char *)dev->dev_addr);
708 		tipc_reset_bearer(net, b);
709 		break;
710 	case NETDEV_UNREGISTER:
711 	case NETDEV_CHANGENAME:
712 		bearer_disable(net, b);
713 		break;
714 	}
715 	return NOTIFY_OK;
716 }
717 
718 static struct notifier_block notifier = {
719 	.notifier_call  = tipc_l2_device_event,
720 	.priority	= 0,
721 };
722 
723 int tipc_bearer_setup(void)
724 {
725 	return register_netdevice_notifier(&notifier);
726 }
727 
728 void tipc_bearer_cleanup(void)
729 {
730 	unregister_netdevice_notifier(&notifier);
731 }
732 
733 void tipc_bearer_stop(struct net *net)
734 {
735 	struct tipc_net *tn = net_generic(net, tipc_net_id);
736 	struct tipc_bearer *b;
737 	u32 i;
738 
739 	for (i = 0; i < MAX_BEARERS; i++) {
740 		b = rtnl_dereference(tn->bearer_list[i]);
741 		if (b) {
742 			bearer_disable(net, b);
743 			tn->bearer_list[i] = NULL;
744 		}
745 	}
746 }
747 
748 void tipc_clone_to_loopback(struct net *net, struct sk_buff_head *pkts)
749 {
750 	struct net_device *dev = net->loopback_dev;
751 	struct sk_buff *skb, *_skb;
752 	int exp;
753 
754 	skb_queue_walk(pkts, _skb) {
755 		skb = pskb_copy(_skb, GFP_ATOMIC);
756 		if (!skb)
757 			continue;
758 
759 		exp = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
760 		if (exp > 0 && pskb_expand_head(skb, exp, 0, GFP_ATOMIC)) {
761 			kfree_skb(skb);
762 			continue;
763 		}
764 
765 		skb_reset_network_header(skb);
766 		dev_hard_header(skb, dev, ETH_P_TIPC, dev->dev_addr,
767 				dev->dev_addr, skb->len);
768 		skb->dev = dev;
769 		skb->pkt_type = PACKET_HOST;
770 		skb->ip_summed = CHECKSUM_UNNECESSARY;
771 		skb->protocol = eth_type_trans(skb, dev);
772 		netif_rx(skb);
773 	}
774 }
775 
776 static int tipc_loopback_rcv_pkt(struct sk_buff *skb, struct net_device *dev,
777 				 struct packet_type *pt, struct net_device *od)
778 {
779 	consume_skb(skb);
780 	return NET_RX_SUCCESS;
781 }
782 
783 int tipc_attach_loopback(struct net *net)
784 {
785 	struct net_device *dev = net->loopback_dev;
786 	struct tipc_net *tn = tipc_net(net);
787 
788 	if (!dev)
789 		return -ENODEV;
790 
791 	netdev_hold(dev, &tn->loopback_pt.dev_tracker, GFP_KERNEL);
792 	tn->loopback_pt.dev = dev;
793 	tn->loopback_pt.type = htons(ETH_P_TIPC);
794 	tn->loopback_pt.func = tipc_loopback_rcv_pkt;
795 	dev_add_pack(&tn->loopback_pt);
796 	return 0;
797 }
798 
799 void tipc_detach_loopback(struct net *net)
800 {
801 	struct tipc_net *tn = tipc_net(net);
802 
803 	dev_remove_pack(&tn->loopback_pt);
804 	netdev_put(net->loopback_dev, &tn->loopback_pt.dev_tracker);
805 }
806 
807 /* Caller should hold rtnl_lock to protect the bearer */
808 static int __tipc_nl_add_bearer(struct tipc_nl_msg *msg,
809 				struct tipc_bearer *bearer, int nlflags)
810 {
811 	void *hdr;
812 	struct nlattr *attrs;
813 	struct nlattr *prop;
814 
815 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
816 			  nlflags, TIPC_NL_BEARER_GET);
817 	if (!hdr)
818 		return -EMSGSIZE;
819 
820 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER);
821 	if (!attrs)
822 		goto msg_full;
823 
824 	if (nla_put_string(msg->skb, TIPC_NLA_BEARER_NAME, bearer->name))
825 		goto attr_msg_full;
826 
827 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_PROP);
828 	if (!prop)
829 		goto prop_msg_full;
830 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, bearer->priority))
831 		goto prop_msg_full;
832 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, bearer->tolerance))
833 		goto prop_msg_full;
834 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bearer->max_win))
835 		goto prop_msg_full;
836 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP)
837 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, bearer->mtu))
838 			goto prop_msg_full;
839 
840 	nla_nest_end(msg->skb, prop);
841 
842 #ifdef CONFIG_TIPC_MEDIA_UDP
843 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP) {
844 		if (tipc_udp_nl_add_bearer_data(msg, bearer))
845 			goto attr_msg_full;
846 	}
847 #endif
848 
849 	nla_nest_end(msg->skb, attrs);
850 	genlmsg_end(msg->skb, hdr);
851 
852 	return 0;
853 
854 prop_msg_full:
855 	nla_nest_cancel(msg->skb, prop);
856 attr_msg_full:
857 	nla_nest_cancel(msg->skb, attrs);
858 msg_full:
859 	genlmsg_cancel(msg->skb, hdr);
860 
861 	return -EMSGSIZE;
862 }
863 
864 int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb)
865 {
866 	int err;
867 	int i = cb->args[0];
868 	struct tipc_bearer *bearer;
869 	struct tipc_nl_msg msg;
870 	struct net *net = sock_net(skb->sk);
871 	struct tipc_net *tn = net_generic(net, tipc_net_id);
872 
873 	if (i == MAX_BEARERS)
874 		return 0;
875 
876 	msg.skb = skb;
877 	msg.portid = NETLINK_CB(cb->skb).portid;
878 	msg.seq = cb->nlh->nlmsg_seq;
879 
880 	rtnl_lock();
881 	for (i = 0; i < MAX_BEARERS; i++) {
882 		bearer = rtnl_dereference(tn->bearer_list[i]);
883 		if (!bearer)
884 			continue;
885 
886 		err = __tipc_nl_add_bearer(&msg, bearer, NLM_F_MULTI);
887 		if (err)
888 			break;
889 	}
890 	rtnl_unlock();
891 
892 	cb->args[0] = i;
893 	return skb->len;
894 }
895 
896 int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info)
897 {
898 	int err;
899 	char *name;
900 	struct sk_buff *rep;
901 	struct tipc_bearer *bearer;
902 	struct tipc_nl_msg msg;
903 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
904 	struct net *net = genl_info_net(info);
905 
906 	if (!info->attrs[TIPC_NLA_BEARER])
907 		return -EINVAL;
908 
909 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
910 					  info->attrs[TIPC_NLA_BEARER],
911 					  tipc_nl_bearer_policy, info->extack);
912 	if (err)
913 		return err;
914 
915 	if (!attrs[TIPC_NLA_BEARER_NAME])
916 		return -EINVAL;
917 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
918 
919 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
920 	if (!rep)
921 		return -ENOMEM;
922 
923 	msg.skb = rep;
924 	msg.portid = info->snd_portid;
925 	msg.seq = info->snd_seq;
926 
927 	rtnl_lock();
928 	bearer = tipc_bearer_find(net, name);
929 	if (!bearer) {
930 		err = -EINVAL;
931 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
932 		goto err_out;
933 	}
934 
935 	err = __tipc_nl_add_bearer(&msg, bearer, 0);
936 	if (err)
937 		goto err_out;
938 	rtnl_unlock();
939 
940 	return genlmsg_reply(rep, info);
941 err_out:
942 	rtnl_unlock();
943 	nlmsg_free(rep);
944 
945 	return err;
946 }
947 
948 int __tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
949 {
950 	int err;
951 	char *name;
952 	struct tipc_bearer *bearer;
953 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
954 	struct net *net = sock_net(skb->sk);
955 
956 	if (!info->attrs[TIPC_NLA_BEARER])
957 		return -EINVAL;
958 
959 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
960 					  info->attrs[TIPC_NLA_BEARER],
961 					  tipc_nl_bearer_policy, info->extack);
962 	if (err)
963 		return err;
964 
965 	if (!attrs[TIPC_NLA_BEARER_NAME])
966 		return -EINVAL;
967 
968 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
969 
970 	bearer = tipc_bearer_find(net, name);
971 	if (!bearer) {
972 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
973 		return -EINVAL;
974 	}
975 
976 	bearer_disable(net, bearer);
977 
978 	return 0;
979 }
980 
981 int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
982 {
983 	int err;
984 
985 	rtnl_lock();
986 	err = __tipc_nl_bearer_disable(skb, info);
987 	rtnl_unlock();
988 
989 	return err;
990 }
991 
992 int __tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
993 {
994 	int err;
995 	char *bearer;
996 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
997 	struct net *net = sock_net(skb->sk);
998 	u32 domain = 0;
999 	u32 prio;
1000 
1001 	prio = TIPC_MEDIA_LINK_PRI;
1002 
1003 	if (!info->attrs[TIPC_NLA_BEARER])
1004 		return -EINVAL;
1005 
1006 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1007 					  info->attrs[TIPC_NLA_BEARER],
1008 					  tipc_nl_bearer_policy, info->extack);
1009 	if (err)
1010 		return err;
1011 
1012 	if (!attrs[TIPC_NLA_BEARER_NAME])
1013 		return -EINVAL;
1014 
1015 	bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1016 
1017 	if (attrs[TIPC_NLA_BEARER_DOMAIN])
1018 		domain = nla_get_u32(attrs[TIPC_NLA_BEARER_DOMAIN]);
1019 
1020 	if (attrs[TIPC_NLA_BEARER_PROP]) {
1021 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1022 
1023 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1024 					      props);
1025 		if (err)
1026 			return err;
1027 
1028 		if (props[TIPC_NLA_PROP_PRIO])
1029 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1030 	}
1031 
1032 	return tipc_enable_bearer(net, bearer, domain, prio, attrs,
1033 				  info->extack);
1034 }
1035 
1036 int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
1037 {
1038 	int err;
1039 
1040 	rtnl_lock();
1041 	err = __tipc_nl_bearer_enable(skb, info);
1042 	rtnl_unlock();
1043 
1044 	return err;
1045 }
1046 
1047 int tipc_nl_bearer_add(struct sk_buff *skb, struct genl_info *info)
1048 {
1049 	int err;
1050 	char *name;
1051 	struct tipc_bearer *b;
1052 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1053 	struct net *net = sock_net(skb->sk);
1054 
1055 	if (!info->attrs[TIPC_NLA_BEARER])
1056 		return -EINVAL;
1057 
1058 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1059 					  info->attrs[TIPC_NLA_BEARER],
1060 					  tipc_nl_bearer_policy, info->extack);
1061 	if (err)
1062 		return err;
1063 
1064 	if (!attrs[TIPC_NLA_BEARER_NAME])
1065 		return -EINVAL;
1066 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1067 
1068 	rtnl_lock();
1069 	b = tipc_bearer_find(net, name);
1070 	if (!b) {
1071 		rtnl_unlock();
1072 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
1073 		return -EINVAL;
1074 	}
1075 
1076 #ifdef CONFIG_TIPC_MEDIA_UDP
1077 	if (attrs[TIPC_NLA_BEARER_UDP_OPTS]) {
1078 		err = tipc_udp_nl_bearer_add(b,
1079 					     attrs[TIPC_NLA_BEARER_UDP_OPTS]);
1080 		if (err) {
1081 			rtnl_unlock();
1082 			return err;
1083 		}
1084 	}
1085 #endif
1086 	rtnl_unlock();
1087 
1088 	return 0;
1089 }
1090 
1091 int __tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1092 {
1093 	struct tipc_bearer *b;
1094 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1095 	struct net *net = sock_net(skb->sk);
1096 	char *name;
1097 	int err;
1098 
1099 	if (!info->attrs[TIPC_NLA_BEARER])
1100 		return -EINVAL;
1101 
1102 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1103 					  info->attrs[TIPC_NLA_BEARER],
1104 					  tipc_nl_bearer_policy, info->extack);
1105 	if (err)
1106 		return err;
1107 
1108 	if (!attrs[TIPC_NLA_BEARER_NAME])
1109 		return -EINVAL;
1110 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1111 
1112 	b = tipc_bearer_find(net, name);
1113 	if (!b) {
1114 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
1115 		return -EINVAL;
1116 	}
1117 
1118 	if (attrs[TIPC_NLA_BEARER_PROP]) {
1119 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1120 
1121 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1122 					      props);
1123 		if (err)
1124 			return err;
1125 
1126 		if (props[TIPC_NLA_PROP_TOL]) {
1127 			b->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1128 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_TOL);
1129 		}
1130 		if (props[TIPC_NLA_PROP_PRIO])
1131 			b->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1132 		if (props[TIPC_NLA_PROP_WIN])
1133 			b->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1134 		if (props[TIPC_NLA_PROP_MTU]) {
1135 			if (b->media->type_id != TIPC_MEDIA_TYPE_UDP) {
1136 				NL_SET_ERR_MSG(info->extack,
1137 					       "MTU property is unsupported");
1138 				return -EINVAL;
1139 			}
1140 #ifdef CONFIG_TIPC_MEDIA_UDP
1141 			if (tipc_udp_mtu_bad(nla_get_u32
1142 					     (props[TIPC_NLA_PROP_MTU]))) {
1143 				NL_SET_ERR_MSG(info->extack,
1144 					       "MTU value is out-of-range");
1145 				return -EINVAL;
1146 			}
1147 			b->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1148 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_MTU);
1149 #endif
1150 		}
1151 	}
1152 
1153 	return 0;
1154 }
1155 
1156 int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1157 {
1158 	int err;
1159 
1160 	rtnl_lock();
1161 	err = __tipc_nl_bearer_set(skb, info);
1162 	rtnl_unlock();
1163 
1164 	return err;
1165 }
1166 
1167 static int __tipc_nl_add_media(struct tipc_nl_msg *msg,
1168 			       struct tipc_media *media, int nlflags)
1169 {
1170 	void *hdr;
1171 	struct nlattr *attrs;
1172 	struct nlattr *prop;
1173 
1174 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1175 			  nlflags, TIPC_NL_MEDIA_GET);
1176 	if (!hdr)
1177 		return -EMSGSIZE;
1178 
1179 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA);
1180 	if (!attrs)
1181 		goto msg_full;
1182 
1183 	if (nla_put_string(msg->skb, TIPC_NLA_MEDIA_NAME, media->name))
1184 		goto attr_msg_full;
1185 
1186 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA_PROP);
1187 	if (!prop)
1188 		goto prop_msg_full;
1189 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, media->priority))
1190 		goto prop_msg_full;
1191 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, media->tolerance))
1192 		goto prop_msg_full;
1193 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, media->max_win))
1194 		goto prop_msg_full;
1195 	if (media->type_id == TIPC_MEDIA_TYPE_UDP)
1196 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, media->mtu))
1197 			goto prop_msg_full;
1198 
1199 	nla_nest_end(msg->skb, prop);
1200 	nla_nest_end(msg->skb, attrs);
1201 	genlmsg_end(msg->skb, hdr);
1202 
1203 	return 0;
1204 
1205 prop_msg_full:
1206 	nla_nest_cancel(msg->skb, prop);
1207 attr_msg_full:
1208 	nla_nest_cancel(msg->skb, attrs);
1209 msg_full:
1210 	genlmsg_cancel(msg->skb, hdr);
1211 
1212 	return -EMSGSIZE;
1213 }
1214 
1215 int tipc_nl_media_dump(struct sk_buff *skb, struct netlink_callback *cb)
1216 {
1217 	int err;
1218 	int i = cb->args[0];
1219 	struct tipc_nl_msg msg;
1220 
1221 	if (i == MAX_MEDIA)
1222 		return 0;
1223 
1224 	msg.skb = skb;
1225 	msg.portid = NETLINK_CB(cb->skb).portid;
1226 	msg.seq = cb->nlh->nlmsg_seq;
1227 
1228 	rtnl_lock();
1229 	for (; media_info_array[i] != NULL; i++) {
1230 		err = __tipc_nl_add_media(&msg, media_info_array[i],
1231 					  NLM_F_MULTI);
1232 		if (err)
1233 			break;
1234 	}
1235 	rtnl_unlock();
1236 
1237 	cb->args[0] = i;
1238 	return skb->len;
1239 }
1240 
1241 int tipc_nl_media_get(struct sk_buff *skb, struct genl_info *info)
1242 {
1243 	int err;
1244 	char *name;
1245 	struct tipc_nl_msg msg;
1246 	struct tipc_media *media;
1247 	struct sk_buff *rep;
1248 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1249 
1250 	if (!info->attrs[TIPC_NLA_MEDIA])
1251 		return -EINVAL;
1252 
1253 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1254 					  info->attrs[TIPC_NLA_MEDIA],
1255 					  tipc_nl_media_policy, info->extack);
1256 	if (err)
1257 		return err;
1258 
1259 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1260 		return -EINVAL;
1261 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1262 
1263 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1264 	if (!rep)
1265 		return -ENOMEM;
1266 
1267 	msg.skb = rep;
1268 	msg.portid = info->snd_portid;
1269 	msg.seq = info->snd_seq;
1270 
1271 	rtnl_lock();
1272 	media = tipc_media_find(name);
1273 	if (!media) {
1274 		NL_SET_ERR_MSG(info->extack, "Media not found");
1275 		err = -EINVAL;
1276 		goto err_out;
1277 	}
1278 
1279 	err = __tipc_nl_add_media(&msg, media, 0);
1280 	if (err)
1281 		goto err_out;
1282 	rtnl_unlock();
1283 
1284 	return genlmsg_reply(rep, info);
1285 err_out:
1286 	rtnl_unlock();
1287 	nlmsg_free(rep);
1288 
1289 	return err;
1290 }
1291 
1292 int __tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1293 {
1294 	int err;
1295 	char *name;
1296 	struct tipc_media *m;
1297 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1298 
1299 	if (!info->attrs[TIPC_NLA_MEDIA])
1300 		return -EINVAL;
1301 
1302 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1303 					  info->attrs[TIPC_NLA_MEDIA],
1304 					  tipc_nl_media_policy, info->extack);
1305 
1306 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1307 		return -EINVAL;
1308 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1309 
1310 	m = tipc_media_find(name);
1311 	if (!m) {
1312 		NL_SET_ERR_MSG(info->extack, "Media not found");
1313 		return -EINVAL;
1314 	}
1315 	if (attrs[TIPC_NLA_MEDIA_PROP]) {
1316 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1317 
1318 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_MEDIA_PROP],
1319 					      props);
1320 		if (err)
1321 			return err;
1322 
1323 		if (props[TIPC_NLA_PROP_TOL])
1324 			m->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1325 		if (props[TIPC_NLA_PROP_PRIO])
1326 			m->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1327 		if (props[TIPC_NLA_PROP_WIN])
1328 			m->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1329 		if (props[TIPC_NLA_PROP_MTU]) {
1330 			if (m->type_id != TIPC_MEDIA_TYPE_UDP) {
1331 				NL_SET_ERR_MSG(info->extack,
1332 					       "MTU property is unsupported");
1333 				return -EINVAL;
1334 			}
1335 #ifdef CONFIG_TIPC_MEDIA_UDP
1336 			if (tipc_udp_mtu_bad(nla_get_u32
1337 					     (props[TIPC_NLA_PROP_MTU]))) {
1338 				NL_SET_ERR_MSG(info->extack,
1339 					       "MTU value is out-of-range");
1340 				return -EINVAL;
1341 			}
1342 			m->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1343 #endif
1344 		}
1345 	}
1346 
1347 	return 0;
1348 }
1349 
1350 int tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1351 {
1352 	int err;
1353 
1354 	rtnl_lock();
1355 	err = __tipc_nl_media_set(skb, info);
1356 	rtnl_unlock();
1357 
1358 	return err;
1359 }
1360