xref: /linux/net/tipc/bearer.c (revision cde5e1b4a90486b4ac731ee43e4e0152cc16887b)
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 = tipc_net(net);
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_bearer *b;
215 
216 	rcu_read_lock();
217 	b = bearer_get(net, bearer_id);
218 	if (b)
219 		tipc_disc_add_dest(b->disc);
220 	rcu_read_unlock();
221 }
222 
223 void tipc_bearer_remove_dest(struct net *net, u32 bearer_id, u32 dest)
224 {
225 	struct tipc_bearer *b;
226 
227 	rcu_read_lock();
228 	b = bearer_get(net, bearer_id);
229 	if (b)
230 		tipc_disc_remove_dest(b->disc);
231 	rcu_read_unlock();
232 }
233 
234 /**
235  * tipc_enable_bearer - enable bearer with the given name
236  * @net: the applicable net namespace
237  * @name: bearer name to enable
238  * @disc_domain: bearer domain
239  * @prio: bearer priority
240  * @attr: nlattr array
241  * @extack: netlink extended ack
242  */
243 static int tipc_enable_bearer(struct net *net, const char *name,
244 			      u32 disc_domain, u32 prio,
245 			      struct nlattr *attr[],
246 			      struct netlink_ext_ack *extack)
247 {
248 	struct tipc_net *tn = tipc_net(net);
249 	struct tipc_bearer_names b_names;
250 	int with_this_prio = 1;
251 	struct tipc_bearer *b;
252 	struct tipc_media *m;
253 	struct sk_buff *skb;
254 	int bearer_id = 0;
255 	int res = -EINVAL;
256 	char *errstr = "";
257 	u32 i;
258 
259 	if (!bearer_name_validate(name, &b_names)) {
260 		NL_SET_ERR_MSG(extack, "Illegal name");
261 		return res;
262 	}
263 
264 	if (prio > TIPC_MAX_LINK_PRI && prio != TIPC_MEDIA_LINK_PRI) {
265 		errstr = "illegal priority";
266 		NL_SET_ERR_MSG(extack, "Illegal priority");
267 		goto rejected;
268 	}
269 
270 	m = tipc_media_find(b_names.media_name);
271 	if (!m) {
272 		errstr = "media not registered";
273 		NL_SET_ERR_MSG(extack, "Media not registered");
274 		goto rejected;
275 	}
276 
277 	if (prio == TIPC_MEDIA_LINK_PRI)
278 		prio = m->priority;
279 
280 	/* Check new bearer vs existing ones and find free bearer id if any */
281 	bearer_id = MAX_BEARERS;
282 	i = MAX_BEARERS;
283 	while (i-- != 0) {
284 		b = rtnl_dereference(tn->bearer_list[i]);
285 		if (!b) {
286 			bearer_id = i;
287 			continue;
288 		}
289 		if (!strcmp(name, b->name)) {
290 			errstr = "already enabled";
291 			NL_SET_ERR_MSG(extack, "Already enabled");
292 			goto rejected;
293 		}
294 
295 		if (b->priority == prio &&
296 		    (++with_this_prio > 2)) {
297 			pr_warn("Bearer <%s>: already 2 bearers with priority %u\n",
298 				name, prio);
299 
300 			if (prio == TIPC_MIN_LINK_PRI) {
301 				errstr = "cannot adjust to lower";
302 				NL_SET_ERR_MSG(extack, "Cannot adjust to lower");
303 				goto rejected;
304 			}
305 
306 			pr_warn("Bearer <%s>: trying with adjusted priority\n",
307 				name);
308 			prio--;
309 			bearer_id = MAX_BEARERS;
310 			i = MAX_BEARERS;
311 			with_this_prio = 1;
312 		}
313 	}
314 
315 	if (bearer_id >= MAX_BEARERS) {
316 		errstr = "max 3 bearers permitted";
317 		NL_SET_ERR_MSG(extack, "Max 3 bearers permitted");
318 		goto rejected;
319 	}
320 
321 	b = kzalloc(sizeof(*b), GFP_ATOMIC);
322 	if (!b)
323 		return -ENOMEM;
324 
325 	strcpy(b->name, name);
326 	b->media = m;
327 	res = m->enable_media(net, b, attr);
328 	if (res) {
329 		kfree(b);
330 		errstr = "failed to enable media";
331 		NL_SET_ERR_MSG(extack, "Failed to enable media");
332 		goto rejected;
333 	}
334 
335 	b->identity = bearer_id;
336 	b->tolerance = m->tolerance;
337 	b->min_win = m->min_win;
338 	b->max_win = m->max_win;
339 	b->domain = disc_domain;
340 	b->net_plane = bearer_id + 'A';
341 	b->priority = prio;
342 	refcount_set(&b->refcnt, 1);
343 
344 	res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
345 	if (res) {
346 		bearer_disable(net, b);
347 		errstr = "failed to create discoverer";
348 		NL_SET_ERR_MSG(extack, "Failed to create discoverer");
349 		goto rejected;
350 	}
351 
352 	/* Create monitoring data before accepting activate messages */
353 	if (tipc_mon_create(net, bearer_id)) {
354 		bearer_disable(net, b);
355 		kfree_skb(skb);
356 		return -ENOMEM;
357 	}
358 
359 	test_and_set_bit_lock(0, &b->up);
360 	rcu_assign_pointer(tn->bearer_list[bearer_id], b);
361 	if (skb)
362 		tipc_bearer_xmit_skb(net, bearer_id, skb, &b->bcast_addr);
363 
364 	pr_info("Enabled bearer <%s>, priority %u\n", name, prio);
365 
366 	return res;
367 rejected:
368 	pr_warn("Enabling of bearer <%s> rejected, %s\n", name, errstr);
369 	return res;
370 }
371 
372 /**
373  * tipc_reset_bearer - Reset all links established over this bearer
374  * @net: the applicable net namespace
375  * @b: the target bearer
376  */
377 static int tipc_reset_bearer(struct net *net, struct tipc_bearer *b)
378 {
379 	pr_info("Resetting bearer <%s>\n", b->name);
380 	tipc_node_delete_links(net, b->identity);
381 	tipc_disc_reset(net, b);
382 	return 0;
383 }
384 
385 bool tipc_bearer_hold(struct tipc_bearer *b)
386 {
387 	return (b && refcount_inc_not_zero(&b->refcnt));
388 }
389 
390 void tipc_bearer_put(struct tipc_bearer *b)
391 {
392 	if (b && refcount_dec_and_test(&b->refcnt))
393 		kfree_rcu(b, rcu);
394 }
395 
396 /**
397  * bearer_disable - disable this bearer
398  * @net: the applicable net namespace
399  * @b: the bearer to disable
400  *
401  * Note: This routine assumes caller holds RTNL lock.
402  */
403 static void bearer_disable(struct net *net, struct tipc_bearer *b)
404 {
405 	struct tipc_net *tn = tipc_net(net);
406 	int bearer_id = b->identity;
407 
408 	pr_info("Disabling bearer <%s>\n", b->name);
409 	clear_bit_unlock(0, &b->up);
410 	tipc_node_delete_links(net, bearer_id);
411 	b->media->disable_media(b);
412 	RCU_INIT_POINTER(b->media_ptr, NULL);
413 	if (b->disc)
414 		tipc_disc_delete(b->disc);
415 	RCU_INIT_POINTER(tn->bearer_list[bearer_id], NULL);
416 	tipc_bearer_put(b);
417 	tipc_mon_delete(net, bearer_id);
418 }
419 
420 int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
421 			 struct nlattr *attr[])
422 {
423 	char *dev_name = strchr((const char *)b->name, ':') + 1;
424 	int hwaddr_len = b->media->hwaddr_len;
425 	u8 node_id[NODE_ID_LEN] = {0,};
426 	struct net_device *dev;
427 
428 	/* Find device with specified name */
429 	dev = dev_get_by_name(net, dev_name);
430 	if (!dev)
431 		return -ENODEV;
432 	if (tipc_mtu_bad(dev)) {
433 		dev_put(dev);
434 		return -EINVAL;
435 	}
436 	if (dev == net->loopback_dev) {
437 		dev_put(dev);
438 		pr_info("Enabling <%s> not permitted\n", b->name);
439 		return -EINVAL;
440 	}
441 
442 	/* Autoconfigure own node identity if needed */
443 	if (!tipc_own_id(net) && hwaddr_len <= NODE_ID_LEN) {
444 		memcpy(node_id, dev->dev_addr, hwaddr_len);
445 		tipc_net_init(net, node_id, 0);
446 	}
447 	if (!tipc_own_id(net)) {
448 		dev_put(dev);
449 		pr_warn("Failed to obtain node identity\n");
450 		return -EINVAL;
451 	}
452 
453 	/* Associate TIPC bearer with L2 bearer */
454 	rcu_assign_pointer(b->media_ptr, dev);
455 	b->pt.dev = dev;
456 	b->pt.type = htons(ETH_P_TIPC);
457 	b->pt.func = tipc_l2_rcv_msg;
458 	dev_add_pack(&b->pt);
459 	memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
460 	memcpy(b->bcast_addr.value, dev->broadcast, hwaddr_len);
461 	b->bcast_addr.media_id = b->media->type_id;
462 	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
463 	b->mtu = dev->mtu;
464 	b->media->raw2addr(b, &b->addr, (const char *)dev->dev_addr);
465 	rcu_assign_pointer(dev->tipc_ptr, b);
466 	return 0;
467 }
468 
469 /* tipc_disable_l2_media - detach TIPC bearer from an L2 interface
470  * @b: the target bearer
471  *
472  * Mark L2 bearer as inactive so that incoming buffers are thrown away
473  */
474 void tipc_disable_l2_media(struct tipc_bearer *b)
475 {
476 	struct net_device *dev;
477 
478 	dev = (struct net_device *)rtnl_dereference(b->media_ptr);
479 	dev_remove_pack(&b->pt);
480 	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
481 	synchronize_net();
482 	dev_put(dev);
483 }
484 
485 /**
486  * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
487  * @net: the associated network namespace
488  * @skb: the packet to be sent
489  * @b: the bearer through which the packet is to be sent
490  * @dest: peer destination address
491  */
492 int tipc_l2_send_msg(struct net *net, struct sk_buff *skb,
493 		     struct tipc_bearer *b, struct tipc_media_addr *dest)
494 {
495 	struct net_device *dev;
496 	int delta;
497 
498 	dev = (struct net_device *)rcu_dereference(b->media_ptr);
499 	if (!dev)
500 		return 0;
501 
502 	delta = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
503 	if ((delta > 0) && pskb_expand_head(skb, delta, 0, GFP_ATOMIC)) {
504 		kfree_skb(skb);
505 		return 0;
506 	}
507 	skb_reset_network_header(skb);
508 	skb->dev = dev;
509 	skb->protocol = htons(ETH_P_TIPC);
510 	dev_hard_header(skb, dev, ETH_P_TIPC, dest->value,
511 			dev->dev_addr, skb->len);
512 	dev_queue_xmit(skb);
513 	return 0;
514 }
515 
516 bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id)
517 {
518 	bool supp = false;
519 	struct tipc_bearer *b;
520 
521 	rcu_read_lock();
522 	b = bearer_get(net, bearer_id);
523 	if (b)
524 		supp = (b->bcast_addr.broadcast == TIPC_BROADCAST_SUPPORT);
525 	rcu_read_unlock();
526 	return supp;
527 }
528 
529 int tipc_bearer_mtu(struct net *net, u32 bearer_id)
530 {
531 	int mtu = 0;
532 	struct tipc_bearer *b;
533 
534 	rcu_read_lock();
535 	b = bearer_get(net, bearer_id);
536 	if (b)
537 		mtu = b->mtu;
538 	rcu_read_unlock();
539 	return mtu;
540 }
541 
542 int tipc_bearer_min_mtu(struct net *net, u32 bearer_id)
543 {
544 	int mtu = TIPC_MIN_BEARER_MTU;
545 	struct tipc_bearer *b;
546 
547 	rcu_read_lock();
548 	b = bearer_get(net, bearer_id);
549 	if (b)
550 		mtu += b->encap_hlen;
551 	rcu_read_unlock();
552 	return mtu;
553 }
554 
555 /* tipc_bearer_xmit_skb - sends buffer to destination over bearer
556  */
557 void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
558 			  struct sk_buff *skb,
559 			  struct tipc_media_addr *dest)
560 {
561 	struct tipc_msg *hdr = buf_msg(skb);
562 	struct tipc_bearer *b;
563 
564 	rcu_read_lock();
565 	b = bearer_get(net, bearer_id);
566 	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr)))) {
567 #ifdef CONFIG_TIPC_CRYPTO
568 		tipc_crypto_xmit(net, &skb, b, dest, NULL);
569 		if (skb)
570 #endif
571 			b->media->send_msg(net, skb, b, dest);
572 	} else {
573 		kfree_skb(skb);
574 	}
575 	rcu_read_unlock();
576 }
577 
578 /* tipc_bearer_xmit() -send buffer to destination over bearer
579  */
580 void tipc_bearer_xmit(struct net *net, u32 bearer_id,
581 		      struct sk_buff_head *xmitq,
582 		      struct tipc_media_addr *dst,
583 		      struct tipc_node *__dnode)
584 {
585 	struct tipc_bearer *b;
586 	struct sk_buff *skb, *tmp;
587 
588 	if (skb_queue_empty(xmitq))
589 		return;
590 
591 	rcu_read_lock();
592 	b = bearer_get(net, bearer_id);
593 	if (unlikely(!b))
594 		__skb_queue_purge(xmitq);
595 	skb_queue_walk_safe(xmitq, skb, tmp) {
596 		__skb_dequeue(xmitq);
597 		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb)))) {
598 #ifdef CONFIG_TIPC_CRYPTO
599 			tipc_crypto_xmit(net, &skb, b, dst, __dnode);
600 			if (skb)
601 #endif
602 				b->media->send_msg(net, skb, b, dst);
603 		} else {
604 			kfree_skb(skb);
605 		}
606 	}
607 	rcu_read_unlock();
608 }
609 
610 /* tipc_bearer_bc_xmit() - broadcast buffers to all destinations
611  */
612 void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
613 			 struct sk_buff_head *xmitq)
614 {
615 	struct tipc_net *tn = tipc_net(net);
616 	struct tipc_media_addr *dst;
617 	int net_id = tn->net_id;
618 	struct tipc_bearer *b;
619 	struct sk_buff *skb, *tmp;
620 	struct tipc_msg *hdr;
621 
622 	rcu_read_lock();
623 	b = bearer_get(net, bearer_id);
624 	if (unlikely(!b || !test_bit(0, &b->up)))
625 		__skb_queue_purge(xmitq);
626 	skb_queue_walk_safe(xmitq, skb, tmp) {
627 		hdr = buf_msg(skb);
628 		msg_set_non_seq(hdr, 1);
629 		msg_set_mc_netid(hdr, net_id);
630 		__skb_dequeue(xmitq);
631 		dst = &b->bcast_addr;
632 #ifdef CONFIG_TIPC_CRYPTO
633 		tipc_crypto_xmit(net, &skb, b, dst, NULL);
634 		if (skb)
635 #endif
636 			b->media->send_msg(net, skb, b, dst);
637 	}
638 	rcu_read_unlock();
639 }
640 
641 /**
642  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
643  * @skb: the received message
644  * @dev: the net device that the packet was received on
645  * @pt: the packet_type structure which was used to register this handler
646  * @orig_dev: the original receive net device in case the device is a bond
647  *
648  * Accept only packets explicitly sent to this node, or broadcast packets;
649  * ignores packets sent using interface multicast, and traffic sent to other
650  * nodes (which can happen if interface is running in promiscuous mode).
651  */
652 static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
653 			   struct packet_type *pt, struct net_device *orig_dev)
654 {
655 	struct tipc_bearer *b;
656 
657 	rcu_read_lock();
658 	b = rcu_dereference(dev->tipc_ptr) ?:
659 		rcu_dereference(orig_dev->tipc_ptr);
660 	if (likely(b && test_bit(0, &b->up) &&
661 		   (skb->pkt_type <= PACKET_MULTICAST))) {
662 		skb_mark_not_on_list(skb);
663 		TIPC_SKB_CB(skb)->flags = 0;
664 		tipc_rcv(dev_net(b->pt.dev), skb, b);
665 		rcu_read_unlock();
666 		return NET_RX_SUCCESS;
667 	}
668 	rcu_read_unlock();
669 	kfree_skb(skb);
670 	return NET_RX_DROP;
671 }
672 
673 /**
674  * tipc_l2_device_event - handle device events from network device
675  * @nb: the context of the notification
676  * @evt: the type of event
677  * @ptr: the net device that the event was on
678  *
679  * This function is called by the Ethernet driver in case of link
680  * change event.
681  */
682 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
683 				void *ptr)
684 {
685 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
686 	struct net *net = dev_net(dev);
687 	struct tipc_bearer *b;
688 
689 	b = rtnl_dereference(dev->tipc_ptr);
690 	if (!b)
691 		return NOTIFY_DONE;
692 
693 	trace_tipc_l2_device_event(dev, b, evt);
694 	switch (evt) {
695 	case NETDEV_CHANGE:
696 		if (netif_carrier_ok(dev) && netif_oper_up(dev)) {
697 			test_and_set_bit_lock(0, &b->up);
698 			break;
699 		}
700 		fallthrough;
701 	case NETDEV_GOING_DOWN:
702 		clear_bit_unlock(0, &b->up);
703 		tipc_reset_bearer(net, b);
704 		break;
705 	case NETDEV_UP:
706 		test_and_set_bit_lock(0, &b->up);
707 		break;
708 	case NETDEV_CHANGEMTU:
709 		if (tipc_mtu_bad(dev)) {
710 			bearer_disable(net, b);
711 			break;
712 		}
713 		b->mtu = dev->mtu;
714 		tipc_reset_bearer(net, b);
715 		break;
716 	case NETDEV_CHANGEADDR:
717 		b->media->raw2addr(b, &b->addr,
718 				   (const char *)dev->dev_addr);
719 		tipc_reset_bearer(net, b);
720 		break;
721 	case NETDEV_UNREGISTER:
722 	case NETDEV_CHANGENAME:
723 		bearer_disable(net, b);
724 		break;
725 	}
726 	return NOTIFY_OK;
727 }
728 
729 static struct notifier_block notifier = {
730 	.notifier_call  = tipc_l2_device_event,
731 	.priority	= 0,
732 };
733 
734 int tipc_bearer_setup(void)
735 {
736 	return register_netdevice_notifier(&notifier);
737 }
738 
739 void tipc_bearer_cleanup(void)
740 {
741 	unregister_netdevice_notifier(&notifier);
742 }
743 
744 void tipc_bearer_stop(struct net *net)
745 {
746 	struct tipc_net *tn = tipc_net(net);
747 	struct tipc_bearer *b;
748 	u32 i;
749 
750 	for (i = 0; i < MAX_BEARERS; i++) {
751 		b = rtnl_dereference(tn->bearer_list[i]);
752 		if (b) {
753 			bearer_disable(net, b);
754 			tn->bearer_list[i] = NULL;
755 		}
756 	}
757 }
758 
759 void tipc_clone_to_loopback(struct net *net, struct sk_buff_head *pkts)
760 {
761 	struct net_device *dev = net->loopback_dev;
762 	struct sk_buff *skb, *_skb;
763 	int exp;
764 
765 	skb_queue_walk(pkts, _skb) {
766 		skb = pskb_copy(_skb, GFP_ATOMIC);
767 		if (!skb)
768 			continue;
769 
770 		exp = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
771 		if (exp > 0 && pskb_expand_head(skb, exp, 0, GFP_ATOMIC)) {
772 			kfree_skb(skb);
773 			continue;
774 		}
775 
776 		skb_reset_network_header(skb);
777 		dev_hard_header(skb, dev, ETH_P_TIPC, dev->dev_addr,
778 				dev->dev_addr, skb->len);
779 		skb->dev = dev;
780 		skb->pkt_type = PACKET_HOST;
781 		skb->ip_summed = CHECKSUM_UNNECESSARY;
782 		skb->protocol = eth_type_trans(skb, dev);
783 		netif_rx(skb);
784 	}
785 }
786 
787 static int tipc_loopback_rcv_pkt(struct sk_buff *skb, struct net_device *dev,
788 				 struct packet_type *pt, struct net_device *od)
789 {
790 	consume_skb(skb);
791 	return NET_RX_SUCCESS;
792 }
793 
794 int tipc_attach_loopback(struct net *net)
795 {
796 	struct net_device *dev = net->loopback_dev;
797 	struct tipc_net *tn = tipc_net(net);
798 
799 	if (!dev)
800 		return -ENODEV;
801 
802 	netdev_hold(dev, &tn->loopback_pt.dev_tracker, GFP_KERNEL);
803 	tn->loopback_pt.dev = dev;
804 	tn->loopback_pt.type = htons(ETH_P_TIPC);
805 	tn->loopback_pt.func = tipc_loopback_rcv_pkt;
806 	dev_add_pack(&tn->loopback_pt);
807 	return 0;
808 }
809 
810 void tipc_detach_loopback(struct net *net)
811 {
812 	struct tipc_net *tn = tipc_net(net);
813 
814 	dev_remove_pack(&tn->loopback_pt);
815 	netdev_put(net->loopback_dev, &tn->loopback_pt.dev_tracker);
816 }
817 
818 /* Caller should hold rtnl_lock to protect the bearer */
819 static int __tipc_nl_add_bearer(struct tipc_nl_msg *msg,
820 				struct tipc_bearer *bearer, int nlflags)
821 {
822 	void *hdr;
823 	struct nlattr *attrs;
824 	struct nlattr *prop;
825 
826 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
827 			  nlflags, TIPC_NL_BEARER_GET);
828 	if (!hdr)
829 		return -EMSGSIZE;
830 
831 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER);
832 	if (!attrs)
833 		goto msg_full;
834 
835 	if (nla_put_string(msg->skb, TIPC_NLA_BEARER_NAME, bearer->name))
836 		goto attr_msg_full;
837 
838 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_PROP);
839 	if (!prop)
840 		goto prop_msg_full;
841 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, bearer->priority))
842 		goto prop_msg_full;
843 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, bearer->tolerance))
844 		goto prop_msg_full;
845 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bearer->max_win))
846 		goto prop_msg_full;
847 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP)
848 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, bearer->mtu))
849 			goto prop_msg_full;
850 
851 	nla_nest_end(msg->skb, prop);
852 
853 #ifdef CONFIG_TIPC_MEDIA_UDP
854 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP) {
855 		if (tipc_udp_nl_add_bearer_data(msg, bearer))
856 			goto attr_msg_full;
857 	}
858 #endif
859 
860 	nla_nest_end(msg->skb, attrs);
861 	genlmsg_end(msg->skb, hdr);
862 
863 	return 0;
864 
865 prop_msg_full:
866 	nla_nest_cancel(msg->skb, prop);
867 attr_msg_full:
868 	nla_nest_cancel(msg->skb, attrs);
869 msg_full:
870 	genlmsg_cancel(msg->skb, hdr);
871 
872 	return -EMSGSIZE;
873 }
874 
875 int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb)
876 {
877 	int err;
878 	int i = cb->args[0];
879 	struct tipc_bearer *bearer;
880 	struct tipc_nl_msg msg;
881 	struct net *net = sock_net(skb->sk);
882 	struct tipc_net *tn = tipc_net(net);
883 
884 	if (i == MAX_BEARERS)
885 		return 0;
886 
887 	msg.skb = skb;
888 	msg.portid = NETLINK_CB(cb->skb).portid;
889 	msg.seq = cb->nlh->nlmsg_seq;
890 
891 	rtnl_lock();
892 	for (i = 0; i < MAX_BEARERS; i++) {
893 		bearer = rtnl_dereference(tn->bearer_list[i]);
894 		if (!bearer)
895 			continue;
896 
897 		err = __tipc_nl_add_bearer(&msg, bearer, NLM_F_MULTI);
898 		if (err)
899 			break;
900 	}
901 	rtnl_unlock();
902 
903 	cb->args[0] = i;
904 	return skb->len;
905 }
906 
907 int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info)
908 {
909 	int err;
910 	char *name;
911 	struct sk_buff *rep;
912 	struct tipc_bearer *bearer;
913 	struct tipc_nl_msg msg;
914 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
915 	struct net *net = genl_info_net(info);
916 
917 	if (!info->attrs[TIPC_NLA_BEARER])
918 		return -EINVAL;
919 
920 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
921 					  info->attrs[TIPC_NLA_BEARER],
922 					  tipc_nl_bearer_policy, info->extack);
923 	if (err)
924 		return err;
925 
926 	if (!attrs[TIPC_NLA_BEARER_NAME])
927 		return -EINVAL;
928 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
929 
930 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
931 	if (!rep)
932 		return -ENOMEM;
933 
934 	msg.skb = rep;
935 	msg.portid = info->snd_portid;
936 	msg.seq = info->snd_seq;
937 
938 	rtnl_lock();
939 	bearer = tipc_bearer_find(net, name);
940 	if (!bearer) {
941 		err = -EINVAL;
942 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
943 		goto err_out;
944 	}
945 
946 	err = __tipc_nl_add_bearer(&msg, bearer, 0);
947 	if (err)
948 		goto err_out;
949 	rtnl_unlock();
950 
951 	return genlmsg_reply(rep, info);
952 err_out:
953 	rtnl_unlock();
954 	nlmsg_free(rep);
955 
956 	return err;
957 }
958 
959 int __tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
960 {
961 	int err;
962 	char *name;
963 	struct tipc_bearer *bearer;
964 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
965 	struct net *net = sock_net(skb->sk);
966 
967 	if (!info->attrs[TIPC_NLA_BEARER])
968 		return -EINVAL;
969 
970 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
971 					  info->attrs[TIPC_NLA_BEARER],
972 					  tipc_nl_bearer_policy, info->extack);
973 	if (err)
974 		return err;
975 
976 	if (!attrs[TIPC_NLA_BEARER_NAME])
977 		return -EINVAL;
978 
979 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
980 
981 	bearer = tipc_bearer_find(net, name);
982 	if (!bearer) {
983 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
984 		return -EINVAL;
985 	}
986 
987 	bearer_disable(net, bearer);
988 
989 	return 0;
990 }
991 
992 int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
993 {
994 	int err;
995 
996 	rtnl_lock();
997 	err = __tipc_nl_bearer_disable(skb, info);
998 	rtnl_unlock();
999 
1000 	return err;
1001 }
1002 
1003 int __tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
1004 {
1005 	int err;
1006 	char *bearer;
1007 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1008 	struct net *net = sock_net(skb->sk);
1009 	u32 domain = 0;
1010 	u32 prio;
1011 
1012 	prio = TIPC_MEDIA_LINK_PRI;
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 
1026 	bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1027 
1028 	if (attrs[TIPC_NLA_BEARER_DOMAIN])
1029 		domain = nla_get_u32(attrs[TIPC_NLA_BEARER_DOMAIN]);
1030 
1031 	if (attrs[TIPC_NLA_BEARER_PROP]) {
1032 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1033 
1034 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1035 					      props);
1036 		if (err)
1037 			return err;
1038 
1039 		if (props[TIPC_NLA_PROP_PRIO])
1040 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1041 	}
1042 
1043 	return tipc_enable_bearer(net, bearer, domain, prio, attrs,
1044 				  info->extack);
1045 }
1046 
1047 int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
1048 {
1049 	int err;
1050 
1051 	rtnl_lock();
1052 	err = __tipc_nl_bearer_enable(skb, info);
1053 	rtnl_unlock();
1054 
1055 	return err;
1056 }
1057 
1058 int tipc_nl_bearer_add(struct sk_buff *skb, struct genl_info *info)
1059 {
1060 	int err;
1061 	char *name;
1062 	struct tipc_bearer *b;
1063 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1064 	struct net *net = sock_net(skb->sk);
1065 
1066 	if (!info->attrs[TIPC_NLA_BEARER])
1067 		return -EINVAL;
1068 
1069 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1070 					  info->attrs[TIPC_NLA_BEARER],
1071 					  tipc_nl_bearer_policy, info->extack);
1072 	if (err)
1073 		return err;
1074 
1075 	if (!attrs[TIPC_NLA_BEARER_NAME])
1076 		return -EINVAL;
1077 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1078 
1079 	rtnl_lock();
1080 	b = tipc_bearer_find(net, name);
1081 	if (!b) {
1082 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
1083 		err = -EINVAL;
1084 		goto out;
1085 	}
1086 
1087 #ifdef CONFIG_TIPC_MEDIA_UDP
1088 	if (attrs[TIPC_NLA_BEARER_UDP_OPTS]) {
1089 		if (b->media->type_id != TIPC_MEDIA_TYPE_UDP) {
1090 			NL_SET_ERR_MSG(info->extack, "UDP option is unsupported");
1091 			err = -EINVAL;
1092 			goto out;
1093 		}
1094 
1095 		err = tipc_udp_nl_bearer_add(b,
1096 					     attrs[TIPC_NLA_BEARER_UDP_OPTS]);
1097 	}
1098 #endif
1099 out:
1100 	rtnl_unlock();
1101 
1102 	return err;
1103 }
1104 
1105 int __tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1106 {
1107 	struct tipc_bearer *b;
1108 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1109 	struct net *net = sock_net(skb->sk);
1110 	char *name;
1111 	int err;
1112 
1113 	if (!info->attrs[TIPC_NLA_BEARER])
1114 		return -EINVAL;
1115 
1116 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1117 					  info->attrs[TIPC_NLA_BEARER],
1118 					  tipc_nl_bearer_policy, info->extack);
1119 	if (err)
1120 		return err;
1121 
1122 	if (!attrs[TIPC_NLA_BEARER_NAME])
1123 		return -EINVAL;
1124 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1125 
1126 	b = tipc_bearer_find(net, name);
1127 	if (!b) {
1128 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
1129 		return -EINVAL;
1130 	}
1131 
1132 	if (attrs[TIPC_NLA_BEARER_PROP]) {
1133 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1134 
1135 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1136 					      props);
1137 		if (err)
1138 			return err;
1139 
1140 		if (props[TIPC_NLA_PROP_TOL]) {
1141 			b->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1142 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_TOL);
1143 		}
1144 		if (props[TIPC_NLA_PROP_PRIO])
1145 			b->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1146 		if (props[TIPC_NLA_PROP_WIN])
1147 			b->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1148 		if (props[TIPC_NLA_PROP_MTU]) {
1149 			if (b->media->type_id != TIPC_MEDIA_TYPE_UDP) {
1150 				NL_SET_ERR_MSG(info->extack,
1151 					       "MTU property is unsupported");
1152 				return -EINVAL;
1153 			}
1154 #ifdef CONFIG_TIPC_MEDIA_UDP
1155 			if (nla_get_u32(props[TIPC_NLA_PROP_MTU]) <
1156 			    b->encap_hlen + TIPC_MIN_BEARER_MTU) {
1157 				NL_SET_ERR_MSG(info->extack,
1158 					       "MTU value is out-of-range");
1159 				return -EINVAL;
1160 			}
1161 			b->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1162 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_MTU);
1163 #endif
1164 		}
1165 	}
1166 
1167 	return 0;
1168 }
1169 
1170 int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1171 {
1172 	int err;
1173 
1174 	rtnl_lock();
1175 	err = __tipc_nl_bearer_set(skb, info);
1176 	rtnl_unlock();
1177 
1178 	return err;
1179 }
1180 
1181 static int __tipc_nl_add_media(struct tipc_nl_msg *msg,
1182 			       struct tipc_media *media, int nlflags)
1183 {
1184 	void *hdr;
1185 	struct nlattr *attrs;
1186 	struct nlattr *prop;
1187 
1188 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1189 			  nlflags, TIPC_NL_MEDIA_GET);
1190 	if (!hdr)
1191 		return -EMSGSIZE;
1192 
1193 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA);
1194 	if (!attrs)
1195 		goto msg_full;
1196 
1197 	if (nla_put_string(msg->skb, TIPC_NLA_MEDIA_NAME, media->name))
1198 		goto attr_msg_full;
1199 
1200 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA_PROP);
1201 	if (!prop)
1202 		goto prop_msg_full;
1203 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, media->priority))
1204 		goto prop_msg_full;
1205 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, media->tolerance))
1206 		goto prop_msg_full;
1207 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, media->max_win))
1208 		goto prop_msg_full;
1209 	if (media->type_id == TIPC_MEDIA_TYPE_UDP)
1210 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, media->mtu))
1211 			goto prop_msg_full;
1212 
1213 	nla_nest_end(msg->skb, prop);
1214 	nla_nest_end(msg->skb, attrs);
1215 	genlmsg_end(msg->skb, hdr);
1216 
1217 	return 0;
1218 
1219 prop_msg_full:
1220 	nla_nest_cancel(msg->skb, prop);
1221 attr_msg_full:
1222 	nla_nest_cancel(msg->skb, attrs);
1223 msg_full:
1224 	genlmsg_cancel(msg->skb, hdr);
1225 
1226 	return -EMSGSIZE;
1227 }
1228 
1229 int tipc_nl_media_dump(struct sk_buff *skb, struct netlink_callback *cb)
1230 {
1231 	int err;
1232 	int i = cb->args[0];
1233 	struct tipc_nl_msg msg;
1234 
1235 	if (i == MAX_MEDIA)
1236 		return 0;
1237 
1238 	msg.skb = skb;
1239 	msg.portid = NETLINK_CB(cb->skb).portid;
1240 	msg.seq = cb->nlh->nlmsg_seq;
1241 
1242 	rtnl_lock();
1243 	for (; media_info_array[i] != NULL; i++) {
1244 		err = __tipc_nl_add_media(&msg, media_info_array[i],
1245 					  NLM_F_MULTI);
1246 		if (err)
1247 			break;
1248 	}
1249 	rtnl_unlock();
1250 
1251 	cb->args[0] = i;
1252 	return skb->len;
1253 }
1254 
1255 int tipc_nl_media_get(struct sk_buff *skb, struct genl_info *info)
1256 {
1257 	int err;
1258 	char *name;
1259 	struct tipc_nl_msg msg;
1260 	struct tipc_media *media;
1261 	struct sk_buff *rep;
1262 	struct nlattr *attrs[TIPC_NLA_MEDIA_MAX + 1];
1263 
1264 	if (!info->attrs[TIPC_NLA_MEDIA])
1265 		return -EINVAL;
1266 
1267 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1268 					  info->attrs[TIPC_NLA_MEDIA],
1269 					  tipc_nl_media_policy, info->extack);
1270 	if (err)
1271 		return err;
1272 
1273 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1274 		return -EINVAL;
1275 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1276 
1277 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1278 	if (!rep)
1279 		return -ENOMEM;
1280 
1281 	msg.skb = rep;
1282 	msg.portid = info->snd_portid;
1283 	msg.seq = info->snd_seq;
1284 
1285 	rtnl_lock();
1286 	media = tipc_media_find(name);
1287 	if (!media) {
1288 		NL_SET_ERR_MSG(info->extack, "Media not found");
1289 		err = -EINVAL;
1290 		goto err_out;
1291 	}
1292 
1293 	err = __tipc_nl_add_media(&msg, media, 0);
1294 	if (err)
1295 		goto err_out;
1296 	rtnl_unlock();
1297 
1298 	return genlmsg_reply(rep, info);
1299 err_out:
1300 	rtnl_unlock();
1301 	nlmsg_free(rep);
1302 
1303 	return err;
1304 }
1305 
1306 int __tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1307 {
1308 	int err;
1309 	char *name;
1310 	struct tipc_media *m;
1311 	struct nlattr *attrs[TIPC_NLA_MEDIA_MAX + 1];
1312 
1313 	if (!info->attrs[TIPC_NLA_MEDIA])
1314 		return -EINVAL;
1315 
1316 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1317 					  info->attrs[TIPC_NLA_MEDIA],
1318 					  tipc_nl_media_policy, info->extack);
1319 
1320 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1321 		return -EINVAL;
1322 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1323 
1324 	m = tipc_media_find(name);
1325 	if (!m) {
1326 		NL_SET_ERR_MSG(info->extack, "Media not found");
1327 		return -EINVAL;
1328 	}
1329 	if (attrs[TIPC_NLA_MEDIA_PROP]) {
1330 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1331 
1332 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_MEDIA_PROP],
1333 					      props);
1334 		if (err)
1335 			return err;
1336 
1337 		if (props[TIPC_NLA_PROP_TOL])
1338 			m->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1339 		if (props[TIPC_NLA_PROP_PRIO])
1340 			m->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1341 		if (props[TIPC_NLA_PROP_WIN])
1342 			m->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1343 		if (props[TIPC_NLA_PROP_MTU]) {
1344 			if (m->type_id != TIPC_MEDIA_TYPE_UDP) {
1345 				NL_SET_ERR_MSG(info->extack,
1346 					       "MTU property is unsupported");
1347 				return -EINVAL;
1348 			}
1349 #ifdef CONFIG_TIPC_MEDIA_UDP
1350 			if (tipc_udp_mtu_bad(nla_get_u32
1351 					     (props[TIPC_NLA_PROP_MTU]))) {
1352 				NL_SET_ERR_MSG(info->extack,
1353 					       "MTU value is out-of-range");
1354 				return -EINVAL;
1355 			}
1356 			m->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1357 #endif
1358 		}
1359 	}
1360 
1361 	return 0;
1362 }
1363 
1364 int tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1365 {
1366 	int err;
1367 
1368 	rtnl_lock();
1369 	err = __tipc_nl_media_set(skb, info);
1370 	rtnl_unlock();
1371 
1372 	return err;
1373 }
1374