xref: /linux/net/tipc/bearer.c (revision 5cd2340cb6a383d04fd88e48fabc2a21a909d6a1)
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 		if (strscpy(name_parts->media_name, media_name,
167 			    TIPC_MAX_MEDIA_NAME) < 0)
168 			return 0;
169 		if (strscpy(name_parts->if_name, if_name,
170 			    TIPC_MAX_IF_NAME) < 0)
171 			return 0;
172 	}
173 	return 1;
174 }
175 
176 /**
177  * tipc_bearer_find - locates bearer object with matching bearer name
178  * @net: the applicable net namespace
179  * @name: bearer name to locate
180  */
181 struct tipc_bearer *tipc_bearer_find(struct net *net, const char *name)
182 {
183 	struct tipc_net *tn = tipc_net(net);
184 	struct tipc_bearer *b;
185 	u32 i;
186 
187 	for (i = 0; i < MAX_BEARERS; i++) {
188 		b = rtnl_dereference(tn->bearer_list[i]);
189 		if (b && (!strcmp(b->name, name)))
190 			return b;
191 	}
192 	return NULL;
193 }
194 
195 /*     tipc_bearer_get_name - get the bearer name from its id.
196  *     @net: network namespace
197  *     @name: a pointer to the buffer where the name will be stored.
198  *     @bearer_id: the id to get the name from.
199  */
200 int tipc_bearer_get_name(struct net *net, char *name, u32 bearer_id)
201 {
202 	struct tipc_net *tn = tipc_net(net);
203 	struct tipc_bearer *b;
204 
205 	if (bearer_id >= MAX_BEARERS)
206 		return -EINVAL;
207 
208 	b = rtnl_dereference(tn->bearer_list[bearer_id]);
209 	if (!b)
210 		return -EINVAL;
211 
212 	strcpy(name, b->name);
213 	return 0;
214 }
215 
216 void tipc_bearer_add_dest(struct net *net, u32 bearer_id, u32 dest)
217 {
218 	struct tipc_bearer *b;
219 
220 	rcu_read_lock();
221 	b = bearer_get(net, bearer_id);
222 	if (b)
223 		tipc_disc_add_dest(b->disc);
224 	rcu_read_unlock();
225 }
226 
227 void tipc_bearer_remove_dest(struct net *net, u32 bearer_id, u32 dest)
228 {
229 	struct tipc_bearer *b;
230 
231 	rcu_read_lock();
232 	b = bearer_get(net, bearer_id);
233 	if (b)
234 		tipc_disc_remove_dest(b->disc);
235 	rcu_read_unlock();
236 }
237 
238 /**
239  * tipc_enable_bearer - enable bearer with the given name
240  * @net: the applicable net namespace
241  * @name: bearer name to enable
242  * @disc_domain: bearer domain
243  * @prio: bearer priority
244  * @attr: nlattr array
245  * @extack: netlink extended ack
246  */
247 static int tipc_enable_bearer(struct net *net, const char *name,
248 			      u32 disc_domain, u32 prio,
249 			      struct nlattr *attr[],
250 			      struct netlink_ext_ack *extack)
251 {
252 	struct tipc_net *tn = tipc_net(net);
253 	struct tipc_bearer_names b_names;
254 	int with_this_prio = 1;
255 	struct tipc_bearer *b;
256 	struct tipc_media *m;
257 	struct sk_buff *skb;
258 	int bearer_id = 0;
259 	int res = -EINVAL;
260 	char *errstr = "";
261 	u32 i;
262 
263 	if (!bearer_name_validate(name, &b_names)) {
264 		NL_SET_ERR_MSG(extack, "Illegal name");
265 		return res;
266 	}
267 
268 	if (prio > TIPC_MAX_LINK_PRI && prio != TIPC_MEDIA_LINK_PRI) {
269 		errstr = "illegal priority";
270 		NL_SET_ERR_MSG(extack, "Illegal priority");
271 		goto rejected;
272 	}
273 
274 	m = tipc_media_find(b_names.media_name);
275 	if (!m) {
276 		errstr = "media not registered";
277 		NL_SET_ERR_MSG(extack, "Media not registered");
278 		goto rejected;
279 	}
280 
281 	if (prio == TIPC_MEDIA_LINK_PRI)
282 		prio = m->priority;
283 
284 	/* Check new bearer vs existing ones and find free bearer id if any */
285 	bearer_id = MAX_BEARERS;
286 	i = MAX_BEARERS;
287 	while (i-- != 0) {
288 		b = rtnl_dereference(tn->bearer_list[i]);
289 		if (!b) {
290 			bearer_id = i;
291 			continue;
292 		}
293 		if (!strcmp(name, b->name)) {
294 			errstr = "already enabled";
295 			NL_SET_ERR_MSG(extack, "Already enabled");
296 			goto rejected;
297 		}
298 
299 		if (b->priority == prio &&
300 		    (++with_this_prio > 2)) {
301 			pr_warn("Bearer <%s>: already 2 bearers with priority %u\n",
302 				name, prio);
303 
304 			if (prio == TIPC_MIN_LINK_PRI) {
305 				errstr = "cannot adjust to lower";
306 				NL_SET_ERR_MSG(extack, "Cannot adjust to lower");
307 				goto rejected;
308 			}
309 
310 			pr_warn("Bearer <%s>: trying with adjusted priority\n",
311 				name);
312 			prio--;
313 			bearer_id = MAX_BEARERS;
314 			i = MAX_BEARERS;
315 			with_this_prio = 1;
316 		}
317 	}
318 
319 	if (bearer_id >= MAX_BEARERS) {
320 		errstr = "max 3 bearers permitted";
321 		NL_SET_ERR_MSG(extack, "Max 3 bearers permitted");
322 		goto rejected;
323 	}
324 
325 	b = kzalloc(sizeof(*b), GFP_ATOMIC);
326 	if (!b)
327 		return -ENOMEM;
328 
329 	strscpy(b->name, name);
330 	b->media = m;
331 	res = m->enable_media(net, b, attr);
332 	if (res) {
333 		kfree(b);
334 		errstr = "failed to enable media";
335 		NL_SET_ERR_MSG(extack, "Failed to enable media");
336 		goto rejected;
337 	}
338 
339 	b->identity = bearer_id;
340 	b->tolerance = m->tolerance;
341 	b->min_win = m->min_win;
342 	b->max_win = m->max_win;
343 	b->domain = disc_domain;
344 	b->net_plane = bearer_id + 'A';
345 	b->priority = prio;
346 	refcount_set(&b->refcnt, 1);
347 
348 	res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
349 	if (res) {
350 		bearer_disable(net, b);
351 		errstr = "failed to create discoverer";
352 		NL_SET_ERR_MSG(extack, "Failed to create discoverer");
353 		goto rejected;
354 	}
355 
356 	/* Create monitoring data before accepting activate messages */
357 	if (tipc_mon_create(net, bearer_id)) {
358 		bearer_disable(net, b);
359 		kfree_skb(skb);
360 		return -ENOMEM;
361 	}
362 
363 	test_and_set_bit_lock(0, &b->up);
364 	rcu_assign_pointer(tn->bearer_list[bearer_id], b);
365 	if (skb)
366 		tipc_bearer_xmit_skb(net, bearer_id, skb, &b->bcast_addr);
367 
368 	pr_info("Enabled bearer <%s>, priority %u\n", name, prio);
369 
370 	return res;
371 rejected:
372 	pr_warn("Enabling of bearer <%s> rejected, %s\n", name, errstr);
373 	return res;
374 }
375 
376 /**
377  * tipc_reset_bearer - Reset all links established over this bearer
378  * @net: the applicable net namespace
379  * @b: the target bearer
380  */
381 static int tipc_reset_bearer(struct net *net, struct tipc_bearer *b)
382 {
383 	pr_info("Resetting bearer <%s>\n", b->name);
384 	tipc_node_delete_links(net, b->identity);
385 	tipc_disc_reset(net, b);
386 	return 0;
387 }
388 
389 bool tipc_bearer_hold(struct tipc_bearer *b)
390 {
391 	return (b && refcount_inc_not_zero(&b->refcnt));
392 }
393 
394 void tipc_bearer_put(struct tipc_bearer *b)
395 {
396 	if (b && refcount_dec_and_test(&b->refcnt))
397 		kfree_rcu(b, rcu);
398 }
399 
400 /**
401  * bearer_disable - disable this bearer
402  * @net: the applicable net namespace
403  * @b: the bearer to disable
404  *
405  * Note: This routine assumes caller holds RTNL lock.
406  */
407 static void bearer_disable(struct net *net, struct tipc_bearer *b)
408 {
409 	struct tipc_net *tn = tipc_net(net);
410 	int bearer_id = b->identity;
411 
412 	pr_info("Disabling bearer <%s>\n", b->name);
413 	clear_bit_unlock(0, &b->up);
414 	tipc_node_delete_links(net, bearer_id);
415 	b->media->disable_media(b);
416 	RCU_INIT_POINTER(b->media_ptr, NULL);
417 	if (b->disc)
418 		tipc_disc_delete(b->disc);
419 	RCU_INIT_POINTER(tn->bearer_list[bearer_id], NULL);
420 	tipc_bearer_put(b);
421 	tipc_mon_delete(net, bearer_id);
422 }
423 
424 int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
425 			 struct nlattr *attr[])
426 {
427 	char *dev_name = strchr((const char *)b->name, ':') + 1;
428 	int hwaddr_len = b->media->hwaddr_len;
429 	u8 node_id[NODE_ID_LEN] = {0,};
430 	struct net_device *dev;
431 
432 	/* Find device with specified name */
433 	dev = dev_get_by_name(net, dev_name);
434 	if (!dev)
435 		return -ENODEV;
436 	if (tipc_mtu_bad(dev)) {
437 		dev_put(dev);
438 		return -EINVAL;
439 	}
440 	if (dev == net->loopback_dev) {
441 		dev_put(dev);
442 		pr_info("Enabling <%s> not permitted\n", b->name);
443 		return -EINVAL;
444 	}
445 
446 	/* Autoconfigure own node identity if needed */
447 	if (!tipc_own_id(net) && hwaddr_len <= NODE_ID_LEN) {
448 		memcpy(node_id, dev->dev_addr, hwaddr_len);
449 		tipc_net_init(net, node_id, 0);
450 	}
451 	if (!tipc_own_id(net)) {
452 		dev_put(dev);
453 		pr_warn("Failed to obtain node identity\n");
454 		return -EINVAL;
455 	}
456 
457 	/* Associate TIPC bearer with L2 bearer */
458 	rcu_assign_pointer(b->media_ptr, dev);
459 	b->pt.dev = dev;
460 	b->pt.type = htons(ETH_P_TIPC);
461 	b->pt.func = tipc_l2_rcv_msg;
462 	dev_add_pack(&b->pt);
463 	memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
464 	memcpy(b->bcast_addr.value, dev->broadcast, hwaddr_len);
465 	b->bcast_addr.media_id = b->media->type_id;
466 	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
467 	b->mtu = dev->mtu;
468 	b->media->raw2addr(b, &b->addr, (const char *)dev->dev_addr);
469 	rcu_assign_pointer(dev->tipc_ptr, b);
470 	return 0;
471 }
472 
473 /* tipc_disable_l2_media - detach TIPC bearer from an L2 interface
474  * @b: the target bearer
475  *
476  * Mark L2 bearer as inactive so that incoming buffers are thrown away
477  */
478 void tipc_disable_l2_media(struct tipc_bearer *b)
479 {
480 	struct net_device *dev;
481 
482 	dev = (struct net_device *)rtnl_dereference(b->media_ptr);
483 	dev_remove_pack(&b->pt);
484 	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
485 	synchronize_net();
486 	dev_put(dev);
487 }
488 
489 /**
490  * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
491  * @net: the associated network namespace
492  * @skb: the packet to be sent
493  * @b: the bearer through which the packet is to be sent
494  * @dest: peer destination address
495  */
496 int tipc_l2_send_msg(struct net *net, struct sk_buff *skb,
497 		     struct tipc_bearer *b, struct tipc_media_addr *dest)
498 {
499 	struct net_device *dev;
500 	int delta;
501 
502 	dev = (struct net_device *)rcu_dereference(b->media_ptr);
503 	if (!dev)
504 		return 0;
505 
506 	delta = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
507 	if ((delta > 0) && pskb_expand_head(skb, delta, 0, GFP_ATOMIC)) {
508 		kfree_skb(skb);
509 		return 0;
510 	}
511 	skb_reset_network_header(skb);
512 	skb->dev = dev;
513 	skb->protocol = htons(ETH_P_TIPC);
514 	dev_hard_header(skb, dev, ETH_P_TIPC, dest->value,
515 			dev->dev_addr, skb->len);
516 	dev_queue_xmit(skb);
517 	return 0;
518 }
519 
520 bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id)
521 {
522 	bool supp = false;
523 	struct tipc_bearer *b;
524 
525 	rcu_read_lock();
526 	b = bearer_get(net, bearer_id);
527 	if (b)
528 		supp = (b->bcast_addr.broadcast == TIPC_BROADCAST_SUPPORT);
529 	rcu_read_unlock();
530 	return supp;
531 }
532 
533 int tipc_bearer_mtu(struct net *net, u32 bearer_id)
534 {
535 	int mtu = 0;
536 	struct tipc_bearer *b;
537 
538 	rcu_read_lock();
539 	b = bearer_get(net, bearer_id);
540 	if (b)
541 		mtu = b->mtu;
542 	rcu_read_unlock();
543 	return mtu;
544 }
545 
546 int tipc_bearer_min_mtu(struct net *net, u32 bearer_id)
547 {
548 	int mtu = TIPC_MIN_BEARER_MTU;
549 	struct tipc_bearer *b;
550 
551 	rcu_read_lock();
552 	b = bearer_get(net, bearer_id);
553 	if (b)
554 		mtu += b->encap_hlen;
555 	rcu_read_unlock();
556 	return mtu;
557 }
558 
559 /* tipc_bearer_xmit_skb - sends buffer to destination over bearer
560  */
561 void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
562 			  struct sk_buff *skb,
563 			  struct tipc_media_addr *dest)
564 {
565 	struct tipc_msg *hdr = buf_msg(skb);
566 	struct tipc_bearer *b;
567 
568 	rcu_read_lock();
569 	b = bearer_get(net, bearer_id);
570 	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr)))) {
571 #ifdef CONFIG_TIPC_CRYPTO
572 		tipc_crypto_xmit(net, &skb, b, dest, NULL);
573 		if (skb)
574 #endif
575 			b->media->send_msg(net, skb, b, dest);
576 	} else {
577 		kfree_skb(skb);
578 	}
579 	rcu_read_unlock();
580 }
581 
582 /* tipc_bearer_xmit() -send buffer to destination over bearer
583  */
584 void tipc_bearer_xmit(struct net *net, u32 bearer_id,
585 		      struct sk_buff_head *xmitq,
586 		      struct tipc_media_addr *dst,
587 		      struct tipc_node *__dnode)
588 {
589 	struct tipc_bearer *b;
590 	struct sk_buff *skb, *tmp;
591 
592 	if (skb_queue_empty(xmitq))
593 		return;
594 
595 	rcu_read_lock();
596 	b = bearer_get(net, bearer_id);
597 	if (unlikely(!b))
598 		__skb_queue_purge(xmitq);
599 	skb_queue_walk_safe(xmitq, skb, tmp) {
600 		__skb_dequeue(xmitq);
601 		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb)))) {
602 #ifdef CONFIG_TIPC_CRYPTO
603 			tipc_crypto_xmit(net, &skb, b, dst, __dnode);
604 			if (skb)
605 #endif
606 				b->media->send_msg(net, skb, b, dst);
607 		} else {
608 			kfree_skb(skb);
609 		}
610 	}
611 	rcu_read_unlock();
612 }
613 
614 /* tipc_bearer_bc_xmit() - broadcast buffers to all destinations
615  */
616 void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
617 			 struct sk_buff_head *xmitq)
618 {
619 	struct tipc_net *tn = tipc_net(net);
620 	struct tipc_media_addr *dst;
621 	int net_id = tn->net_id;
622 	struct tipc_bearer *b;
623 	struct sk_buff *skb, *tmp;
624 	struct tipc_msg *hdr;
625 
626 	rcu_read_lock();
627 	b = bearer_get(net, bearer_id);
628 	if (unlikely(!b || !test_bit(0, &b->up)))
629 		__skb_queue_purge(xmitq);
630 	skb_queue_walk_safe(xmitq, skb, tmp) {
631 		hdr = buf_msg(skb);
632 		msg_set_non_seq(hdr, 1);
633 		msg_set_mc_netid(hdr, net_id);
634 		__skb_dequeue(xmitq);
635 		dst = &b->bcast_addr;
636 #ifdef CONFIG_TIPC_CRYPTO
637 		tipc_crypto_xmit(net, &skb, b, dst, NULL);
638 		if (skb)
639 #endif
640 			b->media->send_msg(net, skb, b, dst);
641 	}
642 	rcu_read_unlock();
643 }
644 
645 /**
646  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
647  * @skb: the received message
648  * @dev: the net device that the packet was received on
649  * @pt: the packet_type structure which was used to register this handler
650  * @orig_dev: the original receive net device in case the device is a bond
651  *
652  * Accept only packets explicitly sent to this node, or broadcast packets;
653  * ignores packets sent using interface multicast, and traffic sent to other
654  * nodes (which can happen if interface is running in promiscuous mode).
655  */
656 static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
657 			   struct packet_type *pt, struct net_device *orig_dev)
658 {
659 	struct tipc_bearer *b;
660 
661 	rcu_read_lock();
662 	b = rcu_dereference(dev->tipc_ptr) ?:
663 		rcu_dereference(orig_dev->tipc_ptr);
664 	if (likely(b && test_bit(0, &b->up) &&
665 		   (skb->pkt_type <= PACKET_MULTICAST))) {
666 		skb_mark_not_on_list(skb);
667 		TIPC_SKB_CB(skb)->flags = 0;
668 		tipc_rcv(dev_net(b->pt.dev), skb, b);
669 		rcu_read_unlock();
670 		return NET_RX_SUCCESS;
671 	}
672 	rcu_read_unlock();
673 	kfree_skb(skb);
674 	return NET_RX_DROP;
675 }
676 
677 /**
678  * tipc_l2_device_event - handle device events from network device
679  * @nb: the context of the notification
680  * @evt: the type of event
681  * @ptr: the net device that the event was on
682  *
683  * This function is called by the Ethernet driver in case of link
684  * change event.
685  */
686 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
687 				void *ptr)
688 {
689 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
690 	struct net *net = dev_net(dev);
691 	struct tipc_bearer *b;
692 
693 	b = rtnl_dereference(dev->tipc_ptr);
694 	if (!b)
695 		return NOTIFY_DONE;
696 
697 	trace_tipc_l2_device_event(dev, b, evt);
698 	switch (evt) {
699 	case NETDEV_CHANGE:
700 		if (netif_carrier_ok(dev) && netif_oper_up(dev)) {
701 			test_and_set_bit_lock(0, &b->up);
702 			break;
703 		}
704 		fallthrough;
705 	case NETDEV_GOING_DOWN:
706 		clear_bit_unlock(0, &b->up);
707 		tipc_reset_bearer(net, b);
708 		break;
709 	case NETDEV_UP:
710 		test_and_set_bit_lock(0, &b->up);
711 		break;
712 	case NETDEV_CHANGEMTU:
713 		if (tipc_mtu_bad(dev)) {
714 			bearer_disable(net, b);
715 			break;
716 		}
717 		b->mtu = dev->mtu;
718 		tipc_reset_bearer(net, b);
719 		break;
720 	case NETDEV_CHANGEADDR:
721 		b->media->raw2addr(b, &b->addr,
722 				   (const char *)dev->dev_addr);
723 		tipc_reset_bearer(net, b);
724 		break;
725 	case NETDEV_UNREGISTER:
726 	case NETDEV_CHANGENAME:
727 		bearer_disable(net, b);
728 		break;
729 	}
730 	return NOTIFY_OK;
731 }
732 
733 static struct notifier_block notifier = {
734 	.notifier_call  = tipc_l2_device_event,
735 	.priority	= 0,
736 };
737 
738 int tipc_bearer_setup(void)
739 {
740 	return register_netdevice_notifier(&notifier);
741 }
742 
743 void tipc_bearer_cleanup(void)
744 {
745 	unregister_netdevice_notifier(&notifier);
746 }
747 
748 void tipc_bearer_stop(struct net *net)
749 {
750 	struct tipc_net *tn = tipc_net(net);
751 	struct tipc_bearer *b;
752 	u32 i;
753 
754 	for (i = 0; i < MAX_BEARERS; i++) {
755 		b = rtnl_dereference(tn->bearer_list[i]);
756 		if (b) {
757 			bearer_disable(net, b);
758 			tn->bearer_list[i] = NULL;
759 		}
760 	}
761 }
762 
763 void tipc_clone_to_loopback(struct net *net, struct sk_buff_head *pkts)
764 {
765 	struct net_device *dev = net->loopback_dev;
766 	struct sk_buff *skb, *_skb;
767 	int exp;
768 
769 	skb_queue_walk(pkts, _skb) {
770 		skb = pskb_copy(_skb, GFP_ATOMIC);
771 		if (!skb)
772 			continue;
773 
774 		exp = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
775 		if (exp > 0 && pskb_expand_head(skb, exp, 0, GFP_ATOMIC)) {
776 			kfree_skb(skb);
777 			continue;
778 		}
779 
780 		skb_reset_network_header(skb);
781 		dev_hard_header(skb, dev, ETH_P_TIPC, dev->dev_addr,
782 				dev->dev_addr, skb->len);
783 		skb->dev = dev;
784 		skb->pkt_type = PACKET_HOST;
785 		skb->ip_summed = CHECKSUM_UNNECESSARY;
786 		skb->protocol = eth_type_trans(skb, dev);
787 		netif_rx(skb);
788 	}
789 }
790 
791 static int tipc_loopback_rcv_pkt(struct sk_buff *skb, struct net_device *dev,
792 				 struct packet_type *pt, struct net_device *od)
793 {
794 	consume_skb(skb);
795 	return NET_RX_SUCCESS;
796 }
797 
798 int tipc_attach_loopback(struct net *net)
799 {
800 	struct net_device *dev = net->loopback_dev;
801 	struct tipc_net *tn = tipc_net(net);
802 
803 	if (!dev)
804 		return -ENODEV;
805 
806 	netdev_hold(dev, &tn->loopback_pt.dev_tracker, GFP_KERNEL);
807 	tn->loopback_pt.dev = dev;
808 	tn->loopback_pt.type = htons(ETH_P_TIPC);
809 	tn->loopback_pt.func = tipc_loopback_rcv_pkt;
810 	dev_add_pack(&tn->loopback_pt);
811 	return 0;
812 }
813 
814 void tipc_detach_loopback(struct net *net)
815 {
816 	struct tipc_net *tn = tipc_net(net);
817 
818 	dev_remove_pack(&tn->loopback_pt);
819 	netdev_put(net->loopback_dev, &tn->loopback_pt.dev_tracker);
820 }
821 
822 /* Caller should hold rtnl_lock to protect the bearer */
823 static int __tipc_nl_add_bearer(struct tipc_nl_msg *msg,
824 				struct tipc_bearer *bearer, int nlflags)
825 {
826 	void *hdr;
827 	struct nlattr *attrs;
828 	struct nlattr *prop;
829 
830 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
831 			  nlflags, TIPC_NL_BEARER_GET);
832 	if (!hdr)
833 		return -EMSGSIZE;
834 
835 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER);
836 	if (!attrs)
837 		goto msg_full;
838 
839 	if (nla_put_string(msg->skb, TIPC_NLA_BEARER_NAME, bearer->name))
840 		goto attr_msg_full;
841 
842 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_PROP);
843 	if (!prop)
844 		goto prop_msg_full;
845 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, bearer->priority))
846 		goto prop_msg_full;
847 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, bearer->tolerance))
848 		goto prop_msg_full;
849 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bearer->max_win))
850 		goto prop_msg_full;
851 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP)
852 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, bearer->mtu))
853 			goto prop_msg_full;
854 
855 	nla_nest_end(msg->skb, prop);
856 
857 #ifdef CONFIG_TIPC_MEDIA_UDP
858 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP) {
859 		if (tipc_udp_nl_add_bearer_data(msg, bearer))
860 			goto attr_msg_full;
861 	}
862 #endif
863 
864 	nla_nest_end(msg->skb, attrs);
865 	genlmsg_end(msg->skb, hdr);
866 
867 	return 0;
868 
869 prop_msg_full:
870 	nla_nest_cancel(msg->skb, prop);
871 attr_msg_full:
872 	nla_nest_cancel(msg->skb, attrs);
873 msg_full:
874 	genlmsg_cancel(msg->skb, hdr);
875 
876 	return -EMSGSIZE;
877 }
878 
879 int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb)
880 {
881 	int err;
882 	int i = cb->args[0];
883 	struct tipc_bearer *bearer;
884 	struct tipc_nl_msg msg;
885 	struct net *net = sock_net(skb->sk);
886 	struct tipc_net *tn = tipc_net(net);
887 
888 	if (i == MAX_BEARERS)
889 		return 0;
890 
891 	msg.skb = skb;
892 	msg.portid = NETLINK_CB(cb->skb).portid;
893 	msg.seq = cb->nlh->nlmsg_seq;
894 
895 	rtnl_lock();
896 	for (i = 0; i < MAX_BEARERS; i++) {
897 		bearer = rtnl_dereference(tn->bearer_list[i]);
898 		if (!bearer)
899 			continue;
900 
901 		err = __tipc_nl_add_bearer(&msg, bearer, NLM_F_MULTI);
902 		if (err)
903 			break;
904 	}
905 	rtnl_unlock();
906 
907 	cb->args[0] = i;
908 	return skb->len;
909 }
910 
911 int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info)
912 {
913 	int err;
914 	char *name;
915 	struct sk_buff *rep;
916 	struct tipc_bearer *bearer;
917 	struct tipc_nl_msg msg;
918 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
919 	struct net *net = genl_info_net(info);
920 
921 	if (!info->attrs[TIPC_NLA_BEARER])
922 		return -EINVAL;
923 
924 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
925 					  info->attrs[TIPC_NLA_BEARER],
926 					  tipc_nl_bearer_policy, info->extack);
927 	if (err)
928 		return err;
929 
930 	if (!attrs[TIPC_NLA_BEARER_NAME])
931 		return -EINVAL;
932 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
933 
934 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
935 	if (!rep)
936 		return -ENOMEM;
937 
938 	msg.skb = rep;
939 	msg.portid = info->snd_portid;
940 	msg.seq = info->snd_seq;
941 
942 	rtnl_lock();
943 	bearer = tipc_bearer_find(net, name);
944 	if (!bearer) {
945 		err = -EINVAL;
946 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
947 		goto err_out;
948 	}
949 
950 	err = __tipc_nl_add_bearer(&msg, bearer, 0);
951 	if (err)
952 		goto err_out;
953 	rtnl_unlock();
954 
955 	return genlmsg_reply(rep, info);
956 err_out:
957 	rtnl_unlock();
958 	nlmsg_free(rep);
959 
960 	return err;
961 }
962 
963 int __tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
964 {
965 	int err;
966 	char *name;
967 	struct tipc_bearer *bearer;
968 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
969 	struct net *net = sock_net(skb->sk);
970 
971 	if (!info->attrs[TIPC_NLA_BEARER])
972 		return -EINVAL;
973 
974 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
975 					  info->attrs[TIPC_NLA_BEARER],
976 					  tipc_nl_bearer_policy, info->extack);
977 	if (err)
978 		return err;
979 
980 	if (!attrs[TIPC_NLA_BEARER_NAME])
981 		return -EINVAL;
982 
983 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
984 
985 	bearer = tipc_bearer_find(net, name);
986 	if (!bearer) {
987 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
988 		return -EINVAL;
989 	}
990 
991 	bearer_disable(net, bearer);
992 
993 	return 0;
994 }
995 
996 int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
997 {
998 	int err;
999 
1000 	rtnl_lock();
1001 	err = __tipc_nl_bearer_disable(skb, info);
1002 	rtnl_unlock();
1003 
1004 	return err;
1005 }
1006 
1007 int __tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
1008 {
1009 	int err;
1010 	char *bearer;
1011 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1012 	struct net *net = sock_net(skb->sk);
1013 	u32 domain = 0;
1014 	u32 prio;
1015 
1016 	prio = TIPC_MEDIA_LINK_PRI;
1017 
1018 	if (!info->attrs[TIPC_NLA_BEARER])
1019 		return -EINVAL;
1020 
1021 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1022 					  info->attrs[TIPC_NLA_BEARER],
1023 					  tipc_nl_bearer_policy, info->extack);
1024 	if (err)
1025 		return err;
1026 
1027 	if (!attrs[TIPC_NLA_BEARER_NAME])
1028 		return -EINVAL;
1029 
1030 	bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1031 
1032 	if (attrs[TIPC_NLA_BEARER_DOMAIN])
1033 		domain = nla_get_u32(attrs[TIPC_NLA_BEARER_DOMAIN]);
1034 
1035 	if (attrs[TIPC_NLA_BEARER_PROP]) {
1036 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1037 
1038 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1039 					      props);
1040 		if (err)
1041 			return err;
1042 
1043 		if (props[TIPC_NLA_PROP_PRIO])
1044 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1045 	}
1046 
1047 	return tipc_enable_bearer(net, bearer, domain, prio, attrs,
1048 				  info->extack);
1049 }
1050 
1051 int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
1052 {
1053 	int err;
1054 
1055 	rtnl_lock();
1056 	err = __tipc_nl_bearer_enable(skb, info);
1057 	rtnl_unlock();
1058 
1059 	return err;
1060 }
1061 
1062 int tipc_nl_bearer_add(struct sk_buff *skb, struct genl_info *info)
1063 {
1064 	int err;
1065 	char *name;
1066 	struct tipc_bearer *b;
1067 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1068 	struct net *net = sock_net(skb->sk);
1069 
1070 	if (!info->attrs[TIPC_NLA_BEARER])
1071 		return -EINVAL;
1072 
1073 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1074 					  info->attrs[TIPC_NLA_BEARER],
1075 					  tipc_nl_bearer_policy, info->extack);
1076 	if (err)
1077 		return err;
1078 
1079 	if (!attrs[TIPC_NLA_BEARER_NAME])
1080 		return -EINVAL;
1081 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1082 
1083 	rtnl_lock();
1084 	b = tipc_bearer_find(net, name);
1085 	if (!b) {
1086 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
1087 		err = -EINVAL;
1088 		goto out;
1089 	}
1090 
1091 #ifdef CONFIG_TIPC_MEDIA_UDP
1092 	if (attrs[TIPC_NLA_BEARER_UDP_OPTS]) {
1093 		if (b->media->type_id != TIPC_MEDIA_TYPE_UDP) {
1094 			NL_SET_ERR_MSG(info->extack, "UDP option is unsupported");
1095 			err = -EINVAL;
1096 			goto out;
1097 		}
1098 
1099 		err = tipc_udp_nl_bearer_add(b,
1100 					     attrs[TIPC_NLA_BEARER_UDP_OPTS]);
1101 	}
1102 #endif
1103 out:
1104 	rtnl_unlock();
1105 
1106 	return err;
1107 }
1108 
1109 int __tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1110 {
1111 	struct tipc_bearer *b;
1112 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1113 	struct net *net = sock_net(skb->sk);
1114 	char *name;
1115 	int err;
1116 
1117 	if (!info->attrs[TIPC_NLA_BEARER])
1118 		return -EINVAL;
1119 
1120 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1121 					  info->attrs[TIPC_NLA_BEARER],
1122 					  tipc_nl_bearer_policy, info->extack);
1123 	if (err)
1124 		return err;
1125 
1126 	if (!attrs[TIPC_NLA_BEARER_NAME])
1127 		return -EINVAL;
1128 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1129 
1130 	b = tipc_bearer_find(net, name);
1131 	if (!b) {
1132 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
1133 		return -EINVAL;
1134 	}
1135 
1136 	if (attrs[TIPC_NLA_BEARER_PROP]) {
1137 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1138 
1139 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1140 					      props);
1141 		if (err)
1142 			return err;
1143 
1144 		if (props[TIPC_NLA_PROP_TOL]) {
1145 			b->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1146 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_TOL);
1147 		}
1148 		if (props[TIPC_NLA_PROP_PRIO])
1149 			b->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1150 		if (props[TIPC_NLA_PROP_WIN])
1151 			b->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1152 		if (props[TIPC_NLA_PROP_MTU]) {
1153 			if (b->media->type_id != TIPC_MEDIA_TYPE_UDP) {
1154 				NL_SET_ERR_MSG(info->extack,
1155 					       "MTU property is unsupported");
1156 				return -EINVAL;
1157 			}
1158 #ifdef CONFIG_TIPC_MEDIA_UDP
1159 			if (nla_get_u32(props[TIPC_NLA_PROP_MTU]) <
1160 			    b->encap_hlen + TIPC_MIN_BEARER_MTU) {
1161 				NL_SET_ERR_MSG(info->extack,
1162 					       "MTU value is out-of-range");
1163 				return -EINVAL;
1164 			}
1165 			b->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1166 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_MTU);
1167 #endif
1168 		}
1169 	}
1170 
1171 	return 0;
1172 }
1173 
1174 int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1175 {
1176 	int err;
1177 
1178 	rtnl_lock();
1179 	err = __tipc_nl_bearer_set(skb, info);
1180 	rtnl_unlock();
1181 
1182 	return err;
1183 }
1184 
1185 static int __tipc_nl_add_media(struct tipc_nl_msg *msg,
1186 			       struct tipc_media *media, int nlflags)
1187 {
1188 	void *hdr;
1189 	struct nlattr *attrs;
1190 	struct nlattr *prop;
1191 
1192 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1193 			  nlflags, TIPC_NL_MEDIA_GET);
1194 	if (!hdr)
1195 		return -EMSGSIZE;
1196 
1197 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA);
1198 	if (!attrs)
1199 		goto msg_full;
1200 
1201 	if (nla_put_string(msg->skb, TIPC_NLA_MEDIA_NAME, media->name))
1202 		goto attr_msg_full;
1203 
1204 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA_PROP);
1205 	if (!prop)
1206 		goto prop_msg_full;
1207 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, media->priority))
1208 		goto prop_msg_full;
1209 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, media->tolerance))
1210 		goto prop_msg_full;
1211 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, media->max_win))
1212 		goto prop_msg_full;
1213 	if (media->type_id == TIPC_MEDIA_TYPE_UDP)
1214 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, media->mtu))
1215 			goto prop_msg_full;
1216 
1217 	nla_nest_end(msg->skb, prop);
1218 	nla_nest_end(msg->skb, attrs);
1219 	genlmsg_end(msg->skb, hdr);
1220 
1221 	return 0;
1222 
1223 prop_msg_full:
1224 	nla_nest_cancel(msg->skb, prop);
1225 attr_msg_full:
1226 	nla_nest_cancel(msg->skb, attrs);
1227 msg_full:
1228 	genlmsg_cancel(msg->skb, hdr);
1229 
1230 	return -EMSGSIZE;
1231 }
1232 
1233 int tipc_nl_media_dump(struct sk_buff *skb, struct netlink_callback *cb)
1234 {
1235 	int err;
1236 	int i = cb->args[0];
1237 	struct tipc_nl_msg msg;
1238 
1239 	if (i == MAX_MEDIA)
1240 		return 0;
1241 
1242 	msg.skb = skb;
1243 	msg.portid = NETLINK_CB(cb->skb).portid;
1244 	msg.seq = cb->nlh->nlmsg_seq;
1245 
1246 	rtnl_lock();
1247 	for (; media_info_array[i] != NULL; i++) {
1248 		err = __tipc_nl_add_media(&msg, media_info_array[i],
1249 					  NLM_F_MULTI);
1250 		if (err)
1251 			break;
1252 	}
1253 	rtnl_unlock();
1254 
1255 	cb->args[0] = i;
1256 	return skb->len;
1257 }
1258 
1259 int tipc_nl_media_get(struct sk_buff *skb, struct genl_info *info)
1260 {
1261 	int err;
1262 	char *name;
1263 	struct tipc_nl_msg msg;
1264 	struct tipc_media *media;
1265 	struct sk_buff *rep;
1266 	struct nlattr *attrs[TIPC_NLA_MEDIA_MAX + 1];
1267 
1268 	if (!info->attrs[TIPC_NLA_MEDIA])
1269 		return -EINVAL;
1270 
1271 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1272 					  info->attrs[TIPC_NLA_MEDIA],
1273 					  tipc_nl_media_policy, info->extack);
1274 	if (err)
1275 		return err;
1276 
1277 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1278 		return -EINVAL;
1279 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1280 
1281 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1282 	if (!rep)
1283 		return -ENOMEM;
1284 
1285 	msg.skb = rep;
1286 	msg.portid = info->snd_portid;
1287 	msg.seq = info->snd_seq;
1288 
1289 	rtnl_lock();
1290 	media = tipc_media_find(name);
1291 	if (!media) {
1292 		NL_SET_ERR_MSG(info->extack, "Media not found");
1293 		err = -EINVAL;
1294 		goto err_out;
1295 	}
1296 
1297 	err = __tipc_nl_add_media(&msg, media, 0);
1298 	if (err)
1299 		goto err_out;
1300 	rtnl_unlock();
1301 
1302 	return genlmsg_reply(rep, info);
1303 err_out:
1304 	rtnl_unlock();
1305 	nlmsg_free(rep);
1306 
1307 	return err;
1308 }
1309 
1310 int __tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1311 {
1312 	int err;
1313 	char *name;
1314 	struct tipc_media *m;
1315 	struct nlattr *attrs[TIPC_NLA_MEDIA_MAX + 1];
1316 
1317 	if (!info->attrs[TIPC_NLA_MEDIA])
1318 		return -EINVAL;
1319 
1320 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1321 					  info->attrs[TIPC_NLA_MEDIA],
1322 					  tipc_nl_media_policy, info->extack);
1323 
1324 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1325 		return -EINVAL;
1326 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1327 
1328 	m = tipc_media_find(name);
1329 	if (!m) {
1330 		NL_SET_ERR_MSG(info->extack, "Media not found");
1331 		return -EINVAL;
1332 	}
1333 	if (attrs[TIPC_NLA_MEDIA_PROP]) {
1334 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1335 
1336 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_MEDIA_PROP],
1337 					      props);
1338 		if (err)
1339 			return err;
1340 
1341 		if (props[TIPC_NLA_PROP_TOL])
1342 			m->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1343 		if (props[TIPC_NLA_PROP_PRIO])
1344 			m->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1345 		if (props[TIPC_NLA_PROP_WIN])
1346 			m->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1347 		if (props[TIPC_NLA_PROP_MTU]) {
1348 			if (m->type_id != TIPC_MEDIA_TYPE_UDP) {
1349 				NL_SET_ERR_MSG(info->extack,
1350 					       "MTU property is unsupported");
1351 				return -EINVAL;
1352 			}
1353 #ifdef CONFIG_TIPC_MEDIA_UDP
1354 			if (tipc_udp_mtu_bad(nla_get_u32
1355 					     (props[TIPC_NLA_PROP_MTU]))) {
1356 				NL_SET_ERR_MSG(info->extack,
1357 					       "MTU value is out-of-range");
1358 				return -EINVAL;
1359 			}
1360 			m->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1361 #endif
1362 		}
1363 	}
1364 
1365 	return 0;
1366 }
1367 
1368 int tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1369 {
1370 	int err;
1371 
1372 	rtnl_lock();
1373 	err = __tipc_nl_media_set(skb, info);
1374 	rtnl_unlock();
1375 
1376 	return err;
1377 }
1378