xref: /openbmc/linux/net/tipc/bearer.c (revision dd21bfa4)
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 		errstr = "illegal name";
263 		NL_SET_ERR_MSG(extack, "Illegal name");
264 		goto rejected;
265 	}
266 
267 	if (prio > TIPC_MAX_LINK_PRI && prio != TIPC_MEDIA_LINK_PRI) {
268 		errstr = "illegal priority";
269 		NL_SET_ERR_MSG(extack, "Illegal priority");
270 		goto rejected;
271 	}
272 
273 	m = tipc_media_find(b_names.media_name);
274 	if (!m) {
275 		errstr = "media not registered";
276 		NL_SET_ERR_MSG(extack, "Media not registered");
277 		goto rejected;
278 	}
279 
280 	if (prio == TIPC_MEDIA_LINK_PRI)
281 		prio = m->priority;
282 
283 	/* Check new bearer vs existing ones and find free bearer id if any */
284 	bearer_id = MAX_BEARERS;
285 	i = MAX_BEARERS;
286 	while (i-- != 0) {
287 		b = rtnl_dereference(tn->bearer_list[i]);
288 		if (!b) {
289 			bearer_id = i;
290 			continue;
291 		}
292 		if (!strcmp(name, b->name)) {
293 			errstr = "already enabled";
294 			NL_SET_ERR_MSG(extack, "Already enabled");
295 			goto rejected;
296 		}
297 
298 		if (b->priority == prio &&
299 		    (++with_this_prio > 2)) {
300 			pr_warn("Bearer <%s>: already 2 bearers with priority %u\n",
301 				name, prio);
302 
303 			if (prio == TIPC_MIN_LINK_PRI) {
304 				errstr = "cannot adjust to lower";
305 				NL_SET_ERR_MSG(extack, "Cannot adjust to lower");
306 				goto rejected;
307 			}
308 
309 			pr_warn("Bearer <%s>: trying with adjusted priority\n",
310 				name);
311 			prio--;
312 			bearer_id = MAX_BEARERS;
313 			i = MAX_BEARERS;
314 			with_this_prio = 1;
315 		}
316 	}
317 
318 	if (bearer_id >= MAX_BEARERS) {
319 		errstr = "max 3 bearers permitted";
320 		NL_SET_ERR_MSG(extack, "Max 3 bearers permitted");
321 		goto rejected;
322 	}
323 
324 	b = kzalloc(sizeof(*b), GFP_ATOMIC);
325 	if (!b)
326 		return -ENOMEM;
327 
328 	strcpy(b->name, name);
329 	b->media = m;
330 	res = m->enable_media(net, b, attr);
331 	if (res) {
332 		kfree(b);
333 		errstr = "failed to enable media";
334 		NL_SET_ERR_MSG(extack, "Failed to enable media");
335 		goto rejected;
336 	}
337 
338 	b->identity = bearer_id;
339 	b->tolerance = m->tolerance;
340 	b->min_win = m->min_win;
341 	b->max_win = m->max_win;
342 	b->domain = disc_domain;
343 	b->net_plane = bearer_id + 'A';
344 	b->priority = prio;
345 	refcount_set(&b->refcnt, 1);
346 
347 	res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
348 	if (res) {
349 		bearer_disable(net, b);
350 		errstr = "failed to create discoverer";
351 		NL_SET_ERR_MSG(extack, "Failed to create discoverer");
352 		goto rejected;
353 	}
354 
355 	test_and_set_bit_lock(0, &b->up);
356 	rcu_assign_pointer(tn->bearer_list[bearer_id], b);
357 	if (skb)
358 		tipc_bearer_xmit_skb(net, bearer_id, skb, &b->bcast_addr);
359 
360 	if (tipc_mon_create(net, bearer_id)) {
361 		bearer_disable(net, b);
362 		return -ENOMEM;
363 	}
364 
365 	pr_info("Enabled bearer <%s>, priority %u\n", name, prio);
366 
367 	return res;
368 rejected:
369 	pr_warn("Enabling of bearer <%s> rejected, %s\n", name, errstr);
370 	return res;
371 }
372 
373 /**
374  * tipc_reset_bearer - Reset all links established over this bearer
375  * @net: the applicable net namespace
376  * @b: the target bearer
377  */
378 static int tipc_reset_bearer(struct net *net, struct tipc_bearer *b)
379 {
380 	pr_info("Resetting bearer <%s>\n", b->name);
381 	tipc_node_delete_links(net, b->identity);
382 	tipc_disc_reset(net, b);
383 	return 0;
384 }
385 
386 bool tipc_bearer_hold(struct tipc_bearer *b)
387 {
388 	return (b && refcount_inc_not_zero(&b->refcnt));
389 }
390 
391 void tipc_bearer_put(struct tipc_bearer *b)
392 {
393 	if (b && refcount_dec_and_test(&b->refcnt))
394 		kfree_rcu(b, rcu);
395 }
396 
397 /**
398  * bearer_disable - disable this bearer
399  * @net: the applicable net namespace
400  * @b: the bearer to disable
401  *
402  * Note: This routine assumes caller holds RTNL lock.
403  */
404 static void bearer_disable(struct net *net, struct tipc_bearer *b)
405 {
406 	struct tipc_net *tn = tipc_net(net);
407 	int bearer_id = b->identity;
408 
409 	pr_info("Disabling bearer <%s>\n", b->name);
410 	clear_bit_unlock(0, &b->up);
411 	tipc_node_delete_links(net, bearer_id);
412 	b->media->disable_media(b);
413 	RCU_INIT_POINTER(b->media_ptr, NULL);
414 	if (b->disc)
415 		tipc_disc_delete(b->disc);
416 	RCU_INIT_POINTER(tn->bearer_list[bearer_id], NULL);
417 	tipc_bearer_put(b);
418 	tipc_mon_delete(net, bearer_id);
419 }
420 
421 int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
422 			 struct nlattr *attr[])
423 {
424 	char *dev_name = strchr((const char *)b->name, ':') + 1;
425 	int hwaddr_len = b->media->hwaddr_len;
426 	u8 node_id[NODE_ID_LEN] = {0,};
427 	struct net_device *dev;
428 
429 	/* Find device with specified name */
430 	dev = dev_get_by_name(net, dev_name);
431 	if (!dev)
432 		return -ENODEV;
433 	if (tipc_mtu_bad(dev, 0)) {
434 		dev_put(dev);
435 		return -EINVAL;
436 	}
437 	if (dev == net->loopback_dev) {
438 		dev_put(dev);
439 		pr_info("Enabling <%s> not permitted\n", b->name);
440 		return -EINVAL;
441 	}
442 
443 	/* Autoconfigure own node identity if needed */
444 	if (!tipc_own_id(net) && hwaddr_len <= NODE_ID_LEN) {
445 		memcpy(node_id, dev->dev_addr, hwaddr_len);
446 		tipc_net_init(net, node_id, 0);
447 	}
448 	if (!tipc_own_id(net)) {
449 		dev_put(dev);
450 		pr_warn("Failed to obtain node identity\n");
451 		return -EINVAL;
452 	}
453 
454 	/* Associate TIPC bearer with L2 bearer */
455 	rcu_assign_pointer(b->media_ptr, dev);
456 	b->pt.dev = dev;
457 	b->pt.type = htons(ETH_P_TIPC);
458 	b->pt.func = tipc_l2_rcv_msg;
459 	dev_add_pack(&b->pt);
460 	memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
461 	memcpy(b->bcast_addr.value, dev->broadcast, hwaddr_len);
462 	b->bcast_addr.media_id = b->media->type_id;
463 	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
464 	b->mtu = dev->mtu;
465 	b->media->raw2addr(b, &b->addr, (const char *)dev->dev_addr);
466 	rcu_assign_pointer(dev->tipc_ptr, b);
467 	return 0;
468 }
469 
470 /* tipc_disable_l2_media - detach TIPC bearer from an L2 interface
471  * @b: the target bearer
472  *
473  * Mark L2 bearer as inactive so that incoming buffers are thrown away
474  */
475 void tipc_disable_l2_media(struct tipc_bearer *b)
476 {
477 	struct net_device *dev;
478 
479 	dev = (struct net_device *)rtnl_dereference(b->media_ptr);
480 	dev_remove_pack(&b->pt);
481 	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
482 	synchronize_net();
483 	dev_put(dev);
484 }
485 
486 /**
487  * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
488  * @net: the associated network namespace
489  * @skb: the packet to be sent
490  * @b: the bearer through which the packet is to be sent
491  * @dest: peer destination address
492  */
493 int tipc_l2_send_msg(struct net *net, struct sk_buff *skb,
494 		     struct tipc_bearer *b, struct tipc_media_addr *dest)
495 {
496 	struct net_device *dev;
497 	int delta;
498 
499 	dev = (struct net_device *)rcu_dereference(b->media_ptr);
500 	if (!dev)
501 		return 0;
502 
503 	delta = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
504 	if ((delta > 0) && pskb_expand_head(skb, delta, 0, GFP_ATOMIC)) {
505 		kfree_skb(skb);
506 		return 0;
507 	}
508 	skb_reset_network_header(skb);
509 	skb->dev = dev;
510 	skb->protocol = htons(ETH_P_TIPC);
511 	dev_hard_header(skb, dev, ETH_P_TIPC, dest->value,
512 			dev->dev_addr, skb->len);
513 	dev_queue_xmit(skb);
514 	return 0;
515 }
516 
517 bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id)
518 {
519 	bool supp = false;
520 	struct tipc_bearer *b;
521 
522 	rcu_read_lock();
523 	b = bearer_get(net, bearer_id);
524 	if (b)
525 		supp = (b->bcast_addr.broadcast == TIPC_BROADCAST_SUPPORT);
526 	rcu_read_unlock();
527 	return supp;
528 }
529 
530 int tipc_bearer_mtu(struct net *net, u32 bearer_id)
531 {
532 	int mtu = 0;
533 	struct tipc_bearer *b;
534 
535 	rcu_read_lock();
536 	b = rcu_dereference(tipc_net(net)->bearer_list[bearer_id]);
537 	if (b)
538 		mtu = b->mtu;
539 	rcu_read_unlock();
540 	return mtu;
541 }
542 
543 /* tipc_bearer_xmit_skb - sends buffer to destination over bearer
544  */
545 void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
546 			  struct sk_buff *skb,
547 			  struct tipc_media_addr *dest)
548 {
549 	struct tipc_msg *hdr = buf_msg(skb);
550 	struct tipc_bearer *b;
551 
552 	rcu_read_lock();
553 	b = bearer_get(net, bearer_id);
554 	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr)))) {
555 #ifdef CONFIG_TIPC_CRYPTO
556 		tipc_crypto_xmit(net, &skb, b, dest, NULL);
557 		if (skb)
558 #endif
559 			b->media->send_msg(net, skb, b, dest);
560 	} else {
561 		kfree_skb(skb);
562 	}
563 	rcu_read_unlock();
564 }
565 
566 /* tipc_bearer_xmit() -send buffer to destination over bearer
567  */
568 void tipc_bearer_xmit(struct net *net, u32 bearer_id,
569 		      struct sk_buff_head *xmitq,
570 		      struct tipc_media_addr *dst,
571 		      struct tipc_node *__dnode)
572 {
573 	struct tipc_bearer *b;
574 	struct sk_buff *skb, *tmp;
575 
576 	if (skb_queue_empty(xmitq))
577 		return;
578 
579 	rcu_read_lock();
580 	b = bearer_get(net, bearer_id);
581 	if (unlikely(!b))
582 		__skb_queue_purge(xmitq);
583 	skb_queue_walk_safe(xmitq, skb, tmp) {
584 		__skb_dequeue(xmitq);
585 		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb)))) {
586 #ifdef CONFIG_TIPC_CRYPTO
587 			tipc_crypto_xmit(net, &skb, b, dst, __dnode);
588 			if (skb)
589 #endif
590 				b->media->send_msg(net, skb, b, dst);
591 		} else {
592 			kfree_skb(skb);
593 		}
594 	}
595 	rcu_read_unlock();
596 }
597 
598 /* tipc_bearer_bc_xmit() - broadcast buffers to all destinations
599  */
600 void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
601 			 struct sk_buff_head *xmitq)
602 {
603 	struct tipc_net *tn = tipc_net(net);
604 	struct tipc_media_addr *dst;
605 	int net_id = tn->net_id;
606 	struct tipc_bearer *b;
607 	struct sk_buff *skb, *tmp;
608 	struct tipc_msg *hdr;
609 
610 	rcu_read_lock();
611 	b = bearer_get(net, bearer_id);
612 	if (unlikely(!b || !test_bit(0, &b->up)))
613 		__skb_queue_purge(xmitq);
614 	skb_queue_walk_safe(xmitq, skb, tmp) {
615 		hdr = buf_msg(skb);
616 		msg_set_non_seq(hdr, 1);
617 		msg_set_mc_netid(hdr, net_id);
618 		__skb_dequeue(xmitq);
619 		dst = &b->bcast_addr;
620 #ifdef CONFIG_TIPC_CRYPTO
621 		tipc_crypto_xmit(net, &skb, b, dst, NULL);
622 		if (skb)
623 #endif
624 			b->media->send_msg(net, skb, b, dst);
625 	}
626 	rcu_read_unlock();
627 }
628 
629 /**
630  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
631  * @skb: the received message
632  * @dev: the net device that the packet was received on
633  * @pt: the packet_type structure which was used to register this handler
634  * @orig_dev: the original receive net device in case the device is a bond
635  *
636  * Accept only packets explicitly sent to this node, or broadcast packets;
637  * ignores packets sent using interface multicast, and traffic sent to other
638  * nodes (which can happen if interface is running in promiscuous mode).
639  */
640 static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
641 			   struct packet_type *pt, struct net_device *orig_dev)
642 {
643 	struct tipc_bearer *b;
644 
645 	rcu_read_lock();
646 	b = rcu_dereference(dev->tipc_ptr) ?:
647 		rcu_dereference(orig_dev->tipc_ptr);
648 	if (likely(b && test_bit(0, &b->up) &&
649 		   (skb->pkt_type <= PACKET_MULTICAST))) {
650 		skb_mark_not_on_list(skb);
651 		TIPC_SKB_CB(skb)->flags = 0;
652 		tipc_rcv(dev_net(b->pt.dev), skb, b);
653 		rcu_read_unlock();
654 		return NET_RX_SUCCESS;
655 	}
656 	rcu_read_unlock();
657 	kfree_skb(skb);
658 	return NET_RX_DROP;
659 }
660 
661 /**
662  * tipc_l2_device_event - handle device events from network device
663  * @nb: the context of the notification
664  * @evt: the type of event
665  * @ptr: the net device that the event was on
666  *
667  * This function is called by the Ethernet driver in case of link
668  * change event.
669  */
670 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
671 				void *ptr)
672 {
673 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
674 	struct net *net = dev_net(dev);
675 	struct tipc_bearer *b;
676 
677 	b = rtnl_dereference(dev->tipc_ptr);
678 	if (!b)
679 		return NOTIFY_DONE;
680 
681 	trace_tipc_l2_device_event(dev, b, evt);
682 	switch (evt) {
683 	case NETDEV_CHANGE:
684 		if (netif_carrier_ok(dev) && netif_oper_up(dev)) {
685 			test_and_set_bit_lock(0, &b->up);
686 			break;
687 		}
688 		fallthrough;
689 	case NETDEV_GOING_DOWN:
690 		clear_bit_unlock(0, &b->up);
691 		tipc_reset_bearer(net, b);
692 		break;
693 	case NETDEV_UP:
694 		test_and_set_bit_lock(0, &b->up);
695 		break;
696 	case NETDEV_CHANGEMTU:
697 		if (tipc_mtu_bad(dev, 0)) {
698 			bearer_disable(net, b);
699 			break;
700 		}
701 		b->mtu = dev->mtu;
702 		tipc_reset_bearer(net, b);
703 		break;
704 	case NETDEV_CHANGEADDR:
705 		b->media->raw2addr(b, &b->addr,
706 				   (const char *)dev->dev_addr);
707 		tipc_reset_bearer(net, b);
708 		break;
709 	case NETDEV_UNREGISTER:
710 	case NETDEV_CHANGENAME:
711 		bearer_disable(net, b);
712 		break;
713 	}
714 	return NOTIFY_OK;
715 }
716 
717 static struct notifier_block notifier = {
718 	.notifier_call  = tipc_l2_device_event,
719 	.priority	= 0,
720 };
721 
722 int tipc_bearer_setup(void)
723 {
724 	return register_netdevice_notifier(&notifier);
725 }
726 
727 void tipc_bearer_cleanup(void)
728 {
729 	unregister_netdevice_notifier(&notifier);
730 }
731 
732 void tipc_bearer_stop(struct net *net)
733 {
734 	struct tipc_net *tn = net_generic(net, tipc_net_id);
735 	struct tipc_bearer *b;
736 	u32 i;
737 
738 	for (i = 0; i < MAX_BEARERS; i++) {
739 		b = rtnl_dereference(tn->bearer_list[i]);
740 		if (b) {
741 			bearer_disable(net, b);
742 			tn->bearer_list[i] = NULL;
743 		}
744 	}
745 }
746 
747 void tipc_clone_to_loopback(struct net *net, struct sk_buff_head *pkts)
748 {
749 	struct net_device *dev = net->loopback_dev;
750 	struct sk_buff *skb, *_skb;
751 	int exp;
752 
753 	skb_queue_walk(pkts, _skb) {
754 		skb = pskb_copy(_skb, GFP_ATOMIC);
755 		if (!skb)
756 			continue;
757 
758 		exp = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
759 		if (exp > 0 && pskb_expand_head(skb, exp, 0, GFP_ATOMIC)) {
760 			kfree_skb(skb);
761 			continue;
762 		}
763 
764 		skb_reset_network_header(skb);
765 		dev_hard_header(skb, dev, ETH_P_TIPC, dev->dev_addr,
766 				dev->dev_addr, skb->len);
767 		skb->dev = dev;
768 		skb->pkt_type = PACKET_HOST;
769 		skb->ip_summed = CHECKSUM_UNNECESSARY;
770 		skb->protocol = eth_type_trans(skb, dev);
771 		netif_rx_ni(skb);
772 	}
773 }
774 
775 static int tipc_loopback_rcv_pkt(struct sk_buff *skb, struct net_device *dev,
776 				 struct packet_type *pt, struct net_device *od)
777 {
778 	consume_skb(skb);
779 	return NET_RX_SUCCESS;
780 }
781 
782 int tipc_attach_loopback(struct net *net)
783 {
784 	struct net_device *dev = net->loopback_dev;
785 	struct tipc_net *tn = tipc_net(net);
786 
787 	if (!dev)
788 		return -ENODEV;
789 
790 	dev_hold_track(dev, &tn->loopback_pt.dev_tracker, GFP_KERNEL);
791 	tn->loopback_pt.dev = dev;
792 	tn->loopback_pt.type = htons(ETH_P_TIPC);
793 	tn->loopback_pt.func = tipc_loopback_rcv_pkt;
794 	dev_add_pack(&tn->loopback_pt);
795 	return 0;
796 }
797 
798 void tipc_detach_loopback(struct net *net)
799 {
800 	struct tipc_net *tn = tipc_net(net);
801 
802 	dev_remove_pack(&tn->loopback_pt);
803 	dev_put_track(net->loopback_dev, &tn->loopback_pt.dev_tracker);
804 }
805 
806 /* Caller should hold rtnl_lock to protect the bearer */
807 static int __tipc_nl_add_bearer(struct tipc_nl_msg *msg,
808 				struct tipc_bearer *bearer, int nlflags)
809 {
810 	void *hdr;
811 	struct nlattr *attrs;
812 	struct nlattr *prop;
813 
814 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
815 			  nlflags, TIPC_NL_BEARER_GET);
816 	if (!hdr)
817 		return -EMSGSIZE;
818 
819 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER);
820 	if (!attrs)
821 		goto msg_full;
822 
823 	if (nla_put_string(msg->skb, TIPC_NLA_BEARER_NAME, bearer->name))
824 		goto attr_msg_full;
825 
826 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_PROP);
827 	if (!prop)
828 		goto prop_msg_full;
829 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, bearer->priority))
830 		goto prop_msg_full;
831 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, bearer->tolerance))
832 		goto prop_msg_full;
833 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bearer->max_win))
834 		goto prop_msg_full;
835 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP)
836 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, bearer->mtu))
837 			goto prop_msg_full;
838 
839 	nla_nest_end(msg->skb, prop);
840 
841 #ifdef CONFIG_TIPC_MEDIA_UDP
842 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP) {
843 		if (tipc_udp_nl_add_bearer_data(msg, bearer))
844 			goto attr_msg_full;
845 	}
846 #endif
847 
848 	nla_nest_end(msg->skb, attrs);
849 	genlmsg_end(msg->skb, hdr);
850 
851 	return 0;
852 
853 prop_msg_full:
854 	nla_nest_cancel(msg->skb, prop);
855 attr_msg_full:
856 	nla_nest_cancel(msg->skb, attrs);
857 msg_full:
858 	genlmsg_cancel(msg->skb, hdr);
859 
860 	return -EMSGSIZE;
861 }
862 
863 int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb)
864 {
865 	int err;
866 	int i = cb->args[0];
867 	struct tipc_bearer *bearer;
868 	struct tipc_nl_msg msg;
869 	struct net *net = sock_net(skb->sk);
870 	struct tipc_net *tn = net_generic(net, tipc_net_id);
871 
872 	if (i == MAX_BEARERS)
873 		return 0;
874 
875 	msg.skb = skb;
876 	msg.portid = NETLINK_CB(cb->skb).portid;
877 	msg.seq = cb->nlh->nlmsg_seq;
878 
879 	rtnl_lock();
880 	for (i = 0; i < MAX_BEARERS; i++) {
881 		bearer = rtnl_dereference(tn->bearer_list[i]);
882 		if (!bearer)
883 			continue;
884 
885 		err = __tipc_nl_add_bearer(&msg, bearer, NLM_F_MULTI);
886 		if (err)
887 			break;
888 	}
889 	rtnl_unlock();
890 
891 	cb->args[0] = i;
892 	return skb->len;
893 }
894 
895 int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info)
896 {
897 	int err;
898 	char *name;
899 	struct sk_buff *rep;
900 	struct tipc_bearer *bearer;
901 	struct tipc_nl_msg msg;
902 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
903 	struct net *net = genl_info_net(info);
904 
905 	if (!info->attrs[TIPC_NLA_BEARER])
906 		return -EINVAL;
907 
908 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
909 					  info->attrs[TIPC_NLA_BEARER],
910 					  tipc_nl_bearer_policy, info->extack);
911 	if (err)
912 		return err;
913 
914 	if (!attrs[TIPC_NLA_BEARER_NAME])
915 		return -EINVAL;
916 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
917 
918 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
919 	if (!rep)
920 		return -ENOMEM;
921 
922 	msg.skb = rep;
923 	msg.portid = info->snd_portid;
924 	msg.seq = info->snd_seq;
925 
926 	rtnl_lock();
927 	bearer = tipc_bearer_find(net, name);
928 	if (!bearer) {
929 		err = -EINVAL;
930 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
931 		goto err_out;
932 	}
933 
934 	err = __tipc_nl_add_bearer(&msg, bearer, 0);
935 	if (err)
936 		goto err_out;
937 	rtnl_unlock();
938 
939 	return genlmsg_reply(rep, info);
940 err_out:
941 	rtnl_unlock();
942 	nlmsg_free(rep);
943 
944 	return err;
945 }
946 
947 int __tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
948 {
949 	int err;
950 	char *name;
951 	struct tipc_bearer *bearer;
952 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
953 	struct net *net = sock_net(skb->sk);
954 
955 	if (!info->attrs[TIPC_NLA_BEARER])
956 		return -EINVAL;
957 
958 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
959 					  info->attrs[TIPC_NLA_BEARER],
960 					  tipc_nl_bearer_policy, info->extack);
961 	if (err)
962 		return err;
963 
964 	if (!attrs[TIPC_NLA_BEARER_NAME])
965 		return -EINVAL;
966 
967 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
968 
969 	bearer = tipc_bearer_find(net, name);
970 	if (!bearer) {
971 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
972 		return -EINVAL;
973 	}
974 
975 	bearer_disable(net, bearer);
976 
977 	return 0;
978 }
979 
980 int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
981 {
982 	int err;
983 
984 	rtnl_lock();
985 	err = __tipc_nl_bearer_disable(skb, info);
986 	rtnl_unlock();
987 
988 	return err;
989 }
990 
991 int __tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
992 {
993 	int err;
994 	char *bearer;
995 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
996 	struct net *net = sock_net(skb->sk);
997 	u32 domain = 0;
998 	u32 prio;
999 
1000 	prio = TIPC_MEDIA_LINK_PRI;
1001 
1002 	if (!info->attrs[TIPC_NLA_BEARER])
1003 		return -EINVAL;
1004 
1005 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1006 					  info->attrs[TIPC_NLA_BEARER],
1007 					  tipc_nl_bearer_policy, info->extack);
1008 	if (err)
1009 		return err;
1010 
1011 	if (!attrs[TIPC_NLA_BEARER_NAME])
1012 		return -EINVAL;
1013 
1014 	bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1015 
1016 	if (attrs[TIPC_NLA_BEARER_DOMAIN])
1017 		domain = nla_get_u32(attrs[TIPC_NLA_BEARER_DOMAIN]);
1018 
1019 	if (attrs[TIPC_NLA_BEARER_PROP]) {
1020 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1021 
1022 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1023 					      props);
1024 		if (err)
1025 			return err;
1026 
1027 		if (props[TIPC_NLA_PROP_PRIO])
1028 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1029 	}
1030 
1031 	return tipc_enable_bearer(net, bearer, domain, prio, attrs,
1032 				  info->extack);
1033 }
1034 
1035 int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
1036 {
1037 	int err;
1038 
1039 	rtnl_lock();
1040 	err = __tipc_nl_bearer_enable(skb, info);
1041 	rtnl_unlock();
1042 
1043 	return err;
1044 }
1045 
1046 int tipc_nl_bearer_add(struct sk_buff *skb, struct genl_info *info)
1047 {
1048 	int err;
1049 	char *name;
1050 	struct tipc_bearer *b;
1051 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1052 	struct net *net = sock_net(skb->sk);
1053 
1054 	if (!info->attrs[TIPC_NLA_BEARER])
1055 		return -EINVAL;
1056 
1057 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1058 					  info->attrs[TIPC_NLA_BEARER],
1059 					  tipc_nl_bearer_policy, info->extack);
1060 	if (err)
1061 		return err;
1062 
1063 	if (!attrs[TIPC_NLA_BEARER_NAME])
1064 		return -EINVAL;
1065 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1066 
1067 	rtnl_lock();
1068 	b = tipc_bearer_find(net, name);
1069 	if (!b) {
1070 		rtnl_unlock();
1071 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
1072 		return -EINVAL;
1073 	}
1074 
1075 #ifdef CONFIG_TIPC_MEDIA_UDP
1076 	if (attrs[TIPC_NLA_BEARER_UDP_OPTS]) {
1077 		err = tipc_udp_nl_bearer_add(b,
1078 					     attrs[TIPC_NLA_BEARER_UDP_OPTS]);
1079 		if (err) {
1080 			rtnl_unlock();
1081 			return err;
1082 		}
1083 	}
1084 #endif
1085 	rtnl_unlock();
1086 
1087 	return 0;
1088 }
1089 
1090 int __tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1091 {
1092 	struct tipc_bearer *b;
1093 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1094 	struct net *net = sock_net(skb->sk);
1095 	char *name;
1096 	int err;
1097 
1098 	if (!info->attrs[TIPC_NLA_BEARER])
1099 		return -EINVAL;
1100 
1101 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1102 					  info->attrs[TIPC_NLA_BEARER],
1103 					  tipc_nl_bearer_policy, info->extack);
1104 	if (err)
1105 		return err;
1106 
1107 	if (!attrs[TIPC_NLA_BEARER_NAME])
1108 		return -EINVAL;
1109 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1110 
1111 	b = tipc_bearer_find(net, name);
1112 	if (!b) {
1113 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
1114 		return -EINVAL;
1115 	}
1116 
1117 	if (attrs[TIPC_NLA_BEARER_PROP]) {
1118 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1119 
1120 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1121 					      props);
1122 		if (err)
1123 			return err;
1124 
1125 		if (props[TIPC_NLA_PROP_TOL]) {
1126 			b->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1127 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_TOL);
1128 		}
1129 		if (props[TIPC_NLA_PROP_PRIO])
1130 			b->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1131 		if (props[TIPC_NLA_PROP_WIN])
1132 			b->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1133 		if (props[TIPC_NLA_PROP_MTU]) {
1134 			if (b->media->type_id != TIPC_MEDIA_TYPE_UDP) {
1135 				NL_SET_ERR_MSG(info->extack,
1136 					       "MTU property is unsupported");
1137 				return -EINVAL;
1138 			}
1139 #ifdef CONFIG_TIPC_MEDIA_UDP
1140 			if (tipc_udp_mtu_bad(nla_get_u32
1141 					     (props[TIPC_NLA_PROP_MTU]))) {
1142 				NL_SET_ERR_MSG(info->extack,
1143 					       "MTU value is out-of-range");
1144 				return -EINVAL;
1145 			}
1146 			b->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1147 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_MTU);
1148 #endif
1149 		}
1150 	}
1151 
1152 	return 0;
1153 }
1154 
1155 int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1156 {
1157 	int err;
1158 
1159 	rtnl_lock();
1160 	err = __tipc_nl_bearer_set(skb, info);
1161 	rtnl_unlock();
1162 
1163 	return err;
1164 }
1165 
1166 static int __tipc_nl_add_media(struct tipc_nl_msg *msg,
1167 			       struct tipc_media *media, int nlflags)
1168 {
1169 	void *hdr;
1170 	struct nlattr *attrs;
1171 	struct nlattr *prop;
1172 
1173 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1174 			  nlflags, TIPC_NL_MEDIA_GET);
1175 	if (!hdr)
1176 		return -EMSGSIZE;
1177 
1178 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA);
1179 	if (!attrs)
1180 		goto msg_full;
1181 
1182 	if (nla_put_string(msg->skb, TIPC_NLA_MEDIA_NAME, media->name))
1183 		goto attr_msg_full;
1184 
1185 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA_PROP);
1186 	if (!prop)
1187 		goto prop_msg_full;
1188 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, media->priority))
1189 		goto prop_msg_full;
1190 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, media->tolerance))
1191 		goto prop_msg_full;
1192 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, media->max_win))
1193 		goto prop_msg_full;
1194 	if (media->type_id == TIPC_MEDIA_TYPE_UDP)
1195 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, media->mtu))
1196 			goto prop_msg_full;
1197 
1198 	nla_nest_end(msg->skb, prop);
1199 	nla_nest_end(msg->skb, attrs);
1200 	genlmsg_end(msg->skb, hdr);
1201 
1202 	return 0;
1203 
1204 prop_msg_full:
1205 	nla_nest_cancel(msg->skb, prop);
1206 attr_msg_full:
1207 	nla_nest_cancel(msg->skb, attrs);
1208 msg_full:
1209 	genlmsg_cancel(msg->skb, hdr);
1210 
1211 	return -EMSGSIZE;
1212 }
1213 
1214 int tipc_nl_media_dump(struct sk_buff *skb, struct netlink_callback *cb)
1215 {
1216 	int err;
1217 	int i = cb->args[0];
1218 	struct tipc_nl_msg msg;
1219 
1220 	if (i == MAX_MEDIA)
1221 		return 0;
1222 
1223 	msg.skb = skb;
1224 	msg.portid = NETLINK_CB(cb->skb).portid;
1225 	msg.seq = cb->nlh->nlmsg_seq;
1226 
1227 	rtnl_lock();
1228 	for (; media_info_array[i] != NULL; i++) {
1229 		err = __tipc_nl_add_media(&msg, media_info_array[i],
1230 					  NLM_F_MULTI);
1231 		if (err)
1232 			break;
1233 	}
1234 	rtnl_unlock();
1235 
1236 	cb->args[0] = i;
1237 	return skb->len;
1238 }
1239 
1240 int tipc_nl_media_get(struct sk_buff *skb, struct genl_info *info)
1241 {
1242 	int err;
1243 	char *name;
1244 	struct tipc_nl_msg msg;
1245 	struct tipc_media *media;
1246 	struct sk_buff *rep;
1247 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1248 
1249 	if (!info->attrs[TIPC_NLA_MEDIA])
1250 		return -EINVAL;
1251 
1252 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1253 					  info->attrs[TIPC_NLA_MEDIA],
1254 					  tipc_nl_media_policy, info->extack);
1255 	if (err)
1256 		return err;
1257 
1258 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1259 		return -EINVAL;
1260 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1261 
1262 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1263 	if (!rep)
1264 		return -ENOMEM;
1265 
1266 	msg.skb = rep;
1267 	msg.portid = info->snd_portid;
1268 	msg.seq = info->snd_seq;
1269 
1270 	rtnl_lock();
1271 	media = tipc_media_find(name);
1272 	if (!media) {
1273 		NL_SET_ERR_MSG(info->extack, "Media not found");
1274 		err = -EINVAL;
1275 		goto err_out;
1276 	}
1277 
1278 	err = __tipc_nl_add_media(&msg, media, 0);
1279 	if (err)
1280 		goto err_out;
1281 	rtnl_unlock();
1282 
1283 	return genlmsg_reply(rep, info);
1284 err_out:
1285 	rtnl_unlock();
1286 	nlmsg_free(rep);
1287 
1288 	return err;
1289 }
1290 
1291 int __tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1292 {
1293 	int err;
1294 	char *name;
1295 	struct tipc_media *m;
1296 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1297 
1298 	if (!info->attrs[TIPC_NLA_MEDIA])
1299 		return -EINVAL;
1300 
1301 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1302 					  info->attrs[TIPC_NLA_MEDIA],
1303 					  tipc_nl_media_policy, info->extack);
1304 
1305 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1306 		return -EINVAL;
1307 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1308 
1309 	m = tipc_media_find(name);
1310 	if (!m) {
1311 		NL_SET_ERR_MSG(info->extack, "Media not found");
1312 		return -EINVAL;
1313 	}
1314 	if (attrs[TIPC_NLA_MEDIA_PROP]) {
1315 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1316 
1317 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_MEDIA_PROP],
1318 					      props);
1319 		if (err)
1320 			return err;
1321 
1322 		if (props[TIPC_NLA_PROP_TOL])
1323 			m->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1324 		if (props[TIPC_NLA_PROP_PRIO])
1325 			m->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1326 		if (props[TIPC_NLA_PROP_WIN])
1327 			m->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1328 		if (props[TIPC_NLA_PROP_MTU]) {
1329 			if (m->type_id != TIPC_MEDIA_TYPE_UDP) {
1330 				NL_SET_ERR_MSG(info->extack,
1331 					       "MTU property is unsupported");
1332 				return -EINVAL;
1333 			}
1334 #ifdef CONFIG_TIPC_MEDIA_UDP
1335 			if (tipc_udp_mtu_bad(nla_get_u32
1336 					     (props[TIPC_NLA_PROP_MTU]))) {
1337 				NL_SET_ERR_MSG(info->extack,
1338 					       "MTU value is out-of-range");
1339 				return -EINVAL;
1340 			}
1341 			m->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1342 #endif
1343 		}
1344 	}
1345 
1346 	return 0;
1347 }
1348 
1349 int tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1350 {
1351 	int err;
1352 
1353 	rtnl_lock();
1354 	err = __tipc_nl_media_set(skb, info);
1355 	rtnl_unlock();
1356 
1357 	return err;
1358 }
1359