xref: /linux/net/tipc/bearer.c (revision f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6)
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_obj(*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 	RCU_INIT_POINTER(b->media_ptr, NULL);
486 	synchronize_net();
487 	dev_put(dev);
488 }
489 
490 /**
491  * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
492  * @net: the associated network namespace
493  * @skb: the packet to be sent
494  * @b: the bearer through which the packet is to be sent
495  * @dest: peer destination address
496  */
497 int tipc_l2_send_msg(struct net *net, struct sk_buff *skb,
498 		     struct tipc_bearer *b, struct tipc_media_addr *dest)
499 {
500 	struct net_device *dev;
501 	int delta;
502 
503 	dev = (struct net_device *)rcu_dereference(b->media_ptr);
504 	if (!dev)
505 		return 0;
506 
507 	delta = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
508 	if ((delta > 0) && pskb_expand_head(skb, delta, 0, GFP_ATOMIC)) {
509 		kfree_skb(skb);
510 		return 0;
511 	}
512 	skb_reset_network_header(skb);
513 	skb->dev = dev;
514 	skb->protocol = htons(ETH_P_TIPC);
515 	dev_hard_header(skb, dev, ETH_P_TIPC, dest->value,
516 			dev->dev_addr, skb->len);
517 	dev_queue_xmit(skb);
518 	return 0;
519 }
520 
521 bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id)
522 {
523 	bool supp = false;
524 	struct tipc_bearer *b;
525 
526 	rcu_read_lock();
527 	b = bearer_get(net, bearer_id);
528 	if (b)
529 		supp = (b->bcast_addr.broadcast == TIPC_BROADCAST_SUPPORT);
530 	rcu_read_unlock();
531 	return supp;
532 }
533 
534 int tipc_bearer_mtu(struct net *net, u32 bearer_id)
535 {
536 	int mtu = 0;
537 	struct tipc_bearer *b;
538 
539 	rcu_read_lock();
540 	b = bearer_get(net, bearer_id);
541 	if (b)
542 		mtu = b->mtu;
543 	rcu_read_unlock();
544 	return mtu;
545 }
546 
547 int tipc_bearer_min_mtu(struct net *net, u32 bearer_id)
548 {
549 	int mtu = TIPC_MIN_BEARER_MTU;
550 	struct tipc_bearer *b;
551 
552 	rcu_read_lock();
553 	b = bearer_get(net, bearer_id);
554 	if (b)
555 		mtu += b->encap_hlen;
556 	rcu_read_unlock();
557 	return mtu;
558 }
559 
560 /* tipc_bearer_xmit_skb - sends buffer to destination over bearer
561  */
562 void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
563 			  struct sk_buff *skb,
564 			  struct tipc_media_addr *dest)
565 {
566 	struct tipc_msg *hdr = buf_msg(skb);
567 	struct tipc_bearer *b;
568 
569 	rcu_read_lock();
570 	b = bearer_get(net, bearer_id);
571 	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr)))) {
572 #ifdef CONFIG_TIPC_CRYPTO
573 		tipc_crypto_xmit(net, &skb, b, dest, NULL);
574 		if (skb)
575 #endif
576 			b->media->send_msg(net, skb, b, dest);
577 	} else {
578 		kfree_skb(skb);
579 	}
580 	rcu_read_unlock();
581 }
582 
583 /* tipc_bearer_xmit() -send buffer to destination over bearer
584  */
585 void tipc_bearer_xmit(struct net *net, u32 bearer_id,
586 		      struct sk_buff_head *xmitq,
587 		      struct tipc_media_addr *dst,
588 		      struct tipc_node *__dnode)
589 {
590 	struct tipc_bearer *b;
591 	struct sk_buff *skb, *tmp;
592 
593 	if (skb_queue_empty(xmitq))
594 		return;
595 
596 	rcu_read_lock();
597 	b = bearer_get(net, bearer_id);
598 	if (unlikely(!b))
599 		__skb_queue_purge(xmitq);
600 	skb_queue_walk_safe(xmitq, skb, tmp) {
601 		__skb_dequeue(xmitq);
602 		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb)))) {
603 #ifdef CONFIG_TIPC_CRYPTO
604 			tipc_crypto_xmit(net, &skb, b, dst, __dnode);
605 			if (skb)
606 #endif
607 				b->media->send_msg(net, skb, b, dst);
608 		} else {
609 			kfree_skb(skb);
610 		}
611 	}
612 	rcu_read_unlock();
613 }
614 
615 /* tipc_bearer_bc_xmit() - broadcast buffers to all destinations
616  */
617 void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
618 			 struct sk_buff_head *xmitq)
619 {
620 	struct tipc_net *tn = tipc_net(net);
621 	struct tipc_media_addr *dst;
622 	int net_id = tn->net_id;
623 	struct tipc_bearer *b;
624 	struct sk_buff *skb, *tmp;
625 	struct tipc_msg *hdr;
626 
627 	rcu_read_lock();
628 	b = bearer_get(net, bearer_id);
629 	if (unlikely(!b || !test_bit(0, &b->up)))
630 		__skb_queue_purge(xmitq);
631 	skb_queue_walk_safe(xmitq, skb, tmp) {
632 		hdr = buf_msg(skb);
633 		msg_set_non_seq(hdr, 1);
634 		msg_set_mc_netid(hdr, net_id);
635 		__skb_dequeue(xmitq);
636 		dst = &b->bcast_addr;
637 #ifdef CONFIG_TIPC_CRYPTO
638 		tipc_crypto_xmit(net, &skb, b, dst, NULL);
639 		if (skb)
640 #endif
641 			b->media->send_msg(net, skb, b, dst);
642 	}
643 	rcu_read_unlock();
644 }
645 
646 /**
647  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
648  * @skb: the received message
649  * @dev: the net device that the packet was received on
650  * @pt: the packet_type structure which was used to register this handler
651  * @orig_dev: the original receive net device in case the device is a bond
652  *
653  * Accept only packets explicitly sent to this node, or broadcast packets;
654  * ignores packets sent using interface multicast, and traffic sent to other
655  * nodes (which can happen if interface is running in promiscuous mode).
656  */
657 static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
658 			   struct packet_type *pt, struct net_device *orig_dev)
659 {
660 	struct tipc_bearer *b;
661 
662 	rcu_read_lock();
663 	b = rcu_dereference(dev->tipc_ptr) ?:
664 		rcu_dereference(orig_dev->tipc_ptr);
665 	if (likely(b && test_bit(0, &b->up) &&
666 		   (skb->pkt_type <= PACKET_MULTICAST))) {
667 		skb_mark_not_on_list(skb);
668 		TIPC_SKB_CB(skb)->flags = 0;
669 		tipc_rcv(dev_net(b->pt.dev), skb, b);
670 		rcu_read_unlock();
671 		return NET_RX_SUCCESS;
672 	}
673 	rcu_read_unlock();
674 	kfree_skb(skb);
675 	return NET_RX_DROP;
676 }
677 
678 /**
679  * tipc_l2_device_event - handle device events from network device
680  * @nb: the context of the notification
681  * @evt: the type of event
682  * @ptr: the net device that the event was on
683  *
684  * This function is called by the Ethernet driver in case of link
685  * change event.
686  */
687 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
688 				void *ptr)
689 {
690 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
691 	struct net *net = dev_net(dev);
692 	struct tipc_bearer *b;
693 
694 	b = rtnl_dereference(dev->tipc_ptr);
695 	if (!b)
696 		return NOTIFY_DONE;
697 
698 	trace_tipc_l2_device_event(dev, b, evt);
699 	switch (evt) {
700 	case NETDEV_CHANGE:
701 		if (netif_carrier_ok(dev) && netif_oper_up(dev)) {
702 			test_and_set_bit_lock(0, &b->up);
703 			break;
704 		}
705 		fallthrough;
706 	case NETDEV_GOING_DOWN:
707 		clear_bit_unlock(0, &b->up);
708 		tipc_reset_bearer(net, b);
709 		break;
710 	case NETDEV_UP:
711 		test_and_set_bit_lock(0, &b->up);
712 		break;
713 	case NETDEV_CHANGEMTU:
714 		if (tipc_mtu_bad(dev)) {
715 			bearer_disable(net, b);
716 			break;
717 		}
718 		b->mtu = dev->mtu;
719 		tipc_reset_bearer(net, b);
720 		break;
721 	case NETDEV_CHANGEADDR:
722 		b->media->raw2addr(b, &b->addr,
723 				   (const char *)dev->dev_addr);
724 		tipc_reset_bearer(net, b);
725 		break;
726 	case NETDEV_UNREGISTER:
727 	case NETDEV_CHANGENAME:
728 		bearer_disable(net, b);
729 		break;
730 	}
731 	return NOTIFY_OK;
732 }
733 
734 static struct notifier_block notifier = {
735 	.notifier_call  = tipc_l2_device_event,
736 	.priority	= 0,
737 };
738 
739 int tipc_bearer_setup(void)
740 {
741 	return register_netdevice_notifier(&notifier);
742 }
743 
744 void tipc_bearer_cleanup(void)
745 {
746 	unregister_netdevice_notifier(&notifier);
747 }
748 
749 void tipc_bearer_stop(struct net *net)
750 {
751 	struct tipc_net *tn = tipc_net(net);
752 	struct tipc_bearer *b;
753 	u32 i;
754 
755 	for (i = 0; i < MAX_BEARERS; i++) {
756 		b = rtnl_dereference(tn->bearer_list[i]);
757 		if (b) {
758 			bearer_disable(net, b);
759 			tn->bearer_list[i] = NULL;
760 		}
761 	}
762 }
763 
764 void tipc_clone_to_loopback(struct net *net, struct sk_buff_head *pkts)
765 {
766 	struct net_device *dev = net->loopback_dev;
767 	struct sk_buff *skb, *_skb;
768 	int exp;
769 
770 	skb_queue_walk(pkts, _skb) {
771 		skb = pskb_copy(_skb, GFP_ATOMIC);
772 		if (!skb)
773 			continue;
774 
775 		exp = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
776 		if (exp > 0 && pskb_expand_head(skb, exp, 0, GFP_ATOMIC)) {
777 			kfree_skb(skb);
778 			continue;
779 		}
780 
781 		skb_reset_network_header(skb);
782 		dev_hard_header(skb, dev, ETH_P_TIPC, dev->dev_addr,
783 				dev->dev_addr, skb->len);
784 		skb->dev = dev;
785 		skb->pkt_type = PACKET_HOST;
786 		skb->ip_summed = CHECKSUM_UNNECESSARY;
787 		skb->protocol = eth_type_trans(skb, dev);
788 		netif_rx(skb);
789 	}
790 }
791 
792 static int tipc_loopback_rcv_pkt(struct sk_buff *skb, struct net_device *dev,
793 				 struct packet_type *pt, struct net_device *od)
794 {
795 	consume_skb(skb);
796 	return NET_RX_SUCCESS;
797 }
798 
799 int tipc_attach_loopback(struct net *net)
800 {
801 	struct net_device *dev = net->loopback_dev;
802 	struct tipc_net *tn = tipc_net(net);
803 
804 	if (!dev)
805 		return -ENODEV;
806 
807 	netdev_hold(dev, &tn->loopback_pt.dev_tracker, GFP_KERNEL);
808 	tn->loopback_pt.dev = dev;
809 	tn->loopback_pt.type = htons(ETH_P_TIPC);
810 	tn->loopback_pt.func = tipc_loopback_rcv_pkt;
811 	dev_add_pack(&tn->loopback_pt);
812 	return 0;
813 }
814 
815 void tipc_detach_loopback(struct net *net)
816 {
817 	struct tipc_net *tn = tipc_net(net);
818 
819 	dev_remove_pack(&tn->loopback_pt);
820 	netdev_put(net->loopback_dev, &tn->loopback_pt.dev_tracker);
821 }
822 
823 /* Caller should hold rtnl_lock to protect the bearer */
824 static int __tipc_nl_add_bearer(struct tipc_nl_msg *msg,
825 				struct tipc_bearer *bearer, int nlflags)
826 {
827 	void *hdr;
828 	struct nlattr *attrs;
829 	struct nlattr *prop;
830 
831 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
832 			  nlflags, TIPC_NL_BEARER_GET);
833 	if (!hdr)
834 		return -EMSGSIZE;
835 
836 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER);
837 	if (!attrs)
838 		goto msg_full;
839 
840 	if (nla_put_string(msg->skb, TIPC_NLA_BEARER_NAME, bearer->name))
841 		goto attr_msg_full;
842 
843 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_PROP);
844 	if (!prop)
845 		goto prop_msg_full;
846 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, bearer->priority))
847 		goto prop_msg_full;
848 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, bearer->tolerance))
849 		goto prop_msg_full;
850 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bearer->max_win))
851 		goto prop_msg_full;
852 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP)
853 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, bearer->mtu))
854 			goto prop_msg_full;
855 
856 	nla_nest_end(msg->skb, prop);
857 
858 #ifdef CONFIG_TIPC_MEDIA_UDP
859 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP) {
860 		if (tipc_udp_nl_add_bearer_data(msg, bearer))
861 			goto attr_msg_full;
862 	}
863 #endif
864 
865 	nla_nest_end(msg->skb, attrs);
866 	genlmsg_end(msg->skb, hdr);
867 
868 	return 0;
869 
870 prop_msg_full:
871 	nla_nest_cancel(msg->skb, prop);
872 attr_msg_full:
873 	nla_nest_cancel(msg->skb, attrs);
874 msg_full:
875 	genlmsg_cancel(msg->skb, hdr);
876 
877 	return -EMSGSIZE;
878 }
879 
880 int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb)
881 {
882 	int err;
883 	int i = cb->args[0];
884 	struct tipc_bearer *bearer;
885 	struct tipc_nl_msg msg;
886 	struct net *net = sock_net(skb->sk);
887 	struct tipc_net *tn = tipc_net(net);
888 
889 	if (i == MAX_BEARERS)
890 		return 0;
891 
892 	msg.skb = skb;
893 	msg.portid = NETLINK_CB(cb->skb).portid;
894 	msg.seq = cb->nlh->nlmsg_seq;
895 
896 	rtnl_lock();
897 	for (i = 0; i < MAX_BEARERS; i++) {
898 		bearer = rtnl_dereference(tn->bearer_list[i]);
899 		if (!bearer)
900 			continue;
901 
902 		err = __tipc_nl_add_bearer(&msg, bearer, NLM_F_MULTI);
903 		if (err)
904 			break;
905 	}
906 	rtnl_unlock();
907 
908 	cb->args[0] = i;
909 	return skb->len;
910 }
911 
912 int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info)
913 {
914 	int err;
915 	char *name;
916 	struct sk_buff *rep;
917 	struct tipc_bearer *bearer;
918 	struct tipc_nl_msg msg;
919 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
920 	struct net *net = genl_info_net(info);
921 
922 	if (!info->attrs[TIPC_NLA_BEARER])
923 		return -EINVAL;
924 
925 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
926 					  info->attrs[TIPC_NLA_BEARER],
927 					  tipc_nl_bearer_policy, info->extack);
928 	if (err)
929 		return err;
930 
931 	if (!attrs[TIPC_NLA_BEARER_NAME])
932 		return -EINVAL;
933 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
934 
935 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
936 	if (!rep)
937 		return -ENOMEM;
938 
939 	msg.skb = rep;
940 	msg.portid = info->snd_portid;
941 	msg.seq = info->snd_seq;
942 
943 	rtnl_lock();
944 	bearer = tipc_bearer_find(net, name);
945 	if (!bearer) {
946 		err = -EINVAL;
947 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
948 		goto err_out;
949 	}
950 
951 	err = __tipc_nl_add_bearer(&msg, bearer, 0);
952 	if (err)
953 		goto err_out;
954 	rtnl_unlock();
955 
956 	return genlmsg_reply(rep, info);
957 err_out:
958 	rtnl_unlock();
959 	nlmsg_free(rep);
960 
961 	return err;
962 }
963 
964 int __tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
965 {
966 	int err;
967 	char *name;
968 	struct tipc_bearer *bearer;
969 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
970 	struct net *net = sock_net(skb->sk);
971 
972 	if (!info->attrs[TIPC_NLA_BEARER])
973 		return -EINVAL;
974 
975 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
976 					  info->attrs[TIPC_NLA_BEARER],
977 					  tipc_nl_bearer_policy, info->extack);
978 	if (err)
979 		return err;
980 
981 	if (!attrs[TIPC_NLA_BEARER_NAME])
982 		return -EINVAL;
983 
984 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
985 
986 	bearer = tipc_bearer_find(net, name);
987 	if (!bearer) {
988 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
989 		return -EINVAL;
990 	}
991 
992 	bearer_disable(net, bearer);
993 
994 	return 0;
995 }
996 
997 int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
998 {
999 	int err;
1000 
1001 	rtnl_lock();
1002 	err = __tipc_nl_bearer_disable(skb, info);
1003 	rtnl_unlock();
1004 
1005 	return err;
1006 }
1007 
1008 int __tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
1009 {
1010 	int err;
1011 	char *bearer;
1012 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1013 	struct net *net = sock_net(skb->sk);
1014 	u32 domain = 0;
1015 	u32 prio;
1016 
1017 	prio = TIPC_MEDIA_LINK_PRI;
1018 
1019 	if (!info->attrs[TIPC_NLA_BEARER])
1020 		return -EINVAL;
1021 
1022 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1023 					  info->attrs[TIPC_NLA_BEARER],
1024 					  tipc_nl_bearer_policy, info->extack);
1025 	if (err)
1026 		return err;
1027 
1028 	if (!attrs[TIPC_NLA_BEARER_NAME])
1029 		return -EINVAL;
1030 
1031 	bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1032 
1033 	if (attrs[TIPC_NLA_BEARER_DOMAIN])
1034 		domain = nla_get_u32(attrs[TIPC_NLA_BEARER_DOMAIN]);
1035 
1036 	if (attrs[TIPC_NLA_BEARER_PROP]) {
1037 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1038 
1039 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1040 					      props);
1041 		if (err)
1042 			return err;
1043 
1044 		if (props[TIPC_NLA_PROP_PRIO])
1045 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1046 	}
1047 
1048 	return tipc_enable_bearer(net, bearer, domain, prio, attrs,
1049 				  info->extack);
1050 }
1051 
1052 int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
1053 {
1054 	int err;
1055 
1056 	rtnl_lock();
1057 	err = __tipc_nl_bearer_enable(skb, info);
1058 	rtnl_unlock();
1059 
1060 	return err;
1061 }
1062 
1063 int tipc_nl_bearer_add(struct sk_buff *skb, struct genl_info *info)
1064 {
1065 	int err;
1066 	char *name;
1067 	struct tipc_bearer *b;
1068 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1069 	struct net *net = sock_net(skb->sk);
1070 
1071 	if (!info->attrs[TIPC_NLA_BEARER])
1072 		return -EINVAL;
1073 
1074 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1075 					  info->attrs[TIPC_NLA_BEARER],
1076 					  tipc_nl_bearer_policy, info->extack);
1077 	if (err)
1078 		return err;
1079 
1080 	if (!attrs[TIPC_NLA_BEARER_NAME])
1081 		return -EINVAL;
1082 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1083 
1084 	rtnl_lock();
1085 	b = tipc_bearer_find(net, name);
1086 	if (!b) {
1087 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
1088 		err = -EINVAL;
1089 		goto out;
1090 	}
1091 
1092 #ifdef CONFIG_TIPC_MEDIA_UDP
1093 	if (attrs[TIPC_NLA_BEARER_UDP_OPTS]) {
1094 		if (b->media->type_id != TIPC_MEDIA_TYPE_UDP) {
1095 			NL_SET_ERR_MSG(info->extack, "UDP option is unsupported");
1096 			err = -EINVAL;
1097 			goto out;
1098 		}
1099 
1100 		err = tipc_udp_nl_bearer_add(b,
1101 					     attrs[TIPC_NLA_BEARER_UDP_OPTS]);
1102 	}
1103 #endif
1104 out:
1105 	rtnl_unlock();
1106 
1107 	return err;
1108 }
1109 
1110 int __tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1111 {
1112 	struct tipc_bearer *b;
1113 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1114 	struct net *net = sock_net(skb->sk);
1115 	char *name;
1116 	int err;
1117 
1118 	if (!info->attrs[TIPC_NLA_BEARER])
1119 		return -EINVAL;
1120 
1121 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
1122 					  info->attrs[TIPC_NLA_BEARER],
1123 					  tipc_nl_bearer_policy, info->extack);
1124 	if (err)
1125 		return err;
1126 
1127 	if (!attrs[TIPC_NLA_BEARER_NAME])
1128 		return -EINVAL;
1129 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
1130 
1131 	b = tipc_bearer_find(net, name);
1132 	if (!b) {
1133 		NL_SET_ERR_MSG(info->extack, "Bearer not found");
1134 		return -EINVAL;
1135 	}
1136 
1137 	if (attrs[TIPC_NLA_BEARER_PROP]) {
1138 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1139 
1140 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1141 					      props);
1142 		if (err)
1143 			return err;
1144 
1145 		if (props[TIPC_NLA_PROP_TOL]) {
1146 			b->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1147 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_TOL);
1148 		}
1149 		if (props[TIPC_NLA_PROP_PRIO])
1150 			b->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1151 		if (props[TIPC_NLA_PROP_WIN])
1152 			b->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1153 		if (props[TIPC_NLA_PROP_MTU]) {
1154 			if (b->media->type_id != TIPC_MEDIA_TYPE_UDP) {
1155 				NL_SET_ERR_MSG(info->extack,
1156 					       "MTU property is unsupported");
1157 				return -EINVAL;
1158 			}
1159 #ifdef CONFIG_TIPC_MEDIA_UDP
1160 			if (nla_get_u32(props[TIPC_NLA_PROP_MTU]) <
1161 			    b->encap_hlen + TIPC_MIN_BEARER_MTU) {
1162 				NL_SET_ERR_MSG(info->extack,
1163 					       "MTU value is out-of-range");
1164 				return -EINVAL;
1165 			}
1166 			b->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1167 			tipc_node_apply_property(net, b, TIPC_NLA_PROP_MTU);
1168 #endif
1169 		}
1170 	}
1171 
1172 	return 0;
1173 }
1174 
1175 int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
1176 {
1177 	int err;
1178 
1179 	rtnl_lock();
1180 	err = __tipc_nl_bearer_set(skb, info);
1181 	rtnl_unlock();
1182 
1183 	return err;
1184 }
1185 
1186 static int __tipc_nl_add_media(struct tipc_nl_msg *msg,
1187 			       struct tipc_media *media, int nlflags)
1188 {
1189 	void *hdr;
1190 	struct nlattr *attrs;
1191 	struct nlattr *prop;
1192 
1193 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1194 			  nlflags, TIPC_NL_MEDIA_GET);
1195 	if (!hdr)
1196 		return -EMSGSIZE;
1197 
1198 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA);
1199 	if (!attrs)
1200 		goto msg_full;
1201 
1202 	if (nla_put_string(msg->skb, TIPC_NLA_MEDIA_NAME, media->name))
1203 		goto attr_msg_full;
1204 
1205 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA_PROP);
1206 	if (!prop)
1207 		goto prop_msg_full;
1208 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, media->priority))
1209 		goto prop_msg_full;
1210 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, media->tolerance))
1211 		goto prop_msg_full;
1212 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, media->max_win))
1213 		goto prop_msg_full;
1214 	if (media->type_id == TIPC_MEDIA_TYPE_UDP)
1215 		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, media->mtu))
1216 			goto prop_msg_full;
1217 
1218 	nla_nest_end(msg->skb, prop);
1219 	nla_nest_end(msg->skb, attrs);
1220 	genlmsg_end(msg->skb, hdr);
1221 
1222 	return 0;
1223 
1224 prop_msg_full:
1225 	nla_nest_cancel(msg->skb, prop);
1226 attr_msg_full:
1227 	nla_nest_cancel(msg->skb, attrs);
1228 msg_full:
1229 	genlmsg_cancel(msg->skb, hdr);
1230 
1231 	return -EMSGSIZE;
1232 }
1233 
1234 int tipc_nl_media_dump(struct sk_buff *skb, struct netlink_callback *cb)
1235 {
1236 	int err;
1237 	int i = cb->args[0];
1238 	struct tipc_nl_msg msg;
1239 
1240 	if (i == MAX_MEDIA)
1241 		return 0;
1242 
1243 	msg.skb = skb;
1244 	msg.portid = NETLINK_CB(cb->skb).portid;
1245 	msg.seq = cb->nlh->nlmsg_seq;
1246 
1247 	rtnl_lock();
1248 	for (; media_info_array[i] != NULL; i++) {
1249 		err = __tipc_nl_add_media(&msg, media_info_array[i],
1250 					  NLM_F_MULTI);
1251 		if (err)
1252 			break;
1253 	}
1254 	rtnl_unlock();
1255 
1256 	cb->args[0] = i;
1257 	return skb->len;
1258 }
1259 
1260 int tipc_nl_media_get(struct sk_buff *skb, struct genl_info *info)
1261 {
1262 	int err;
1263 	char *name;
1264 	struct tipc_nl_msg msg;
1265 	struct tipc_media *media;
1266 	struct sk_buff *rep;
1267 	struct nlattr *attrs[TIPC_NLA_MEDIA_MAX + 1];
1268 
1269 	if (!info->attrs[TIPC_NLA_MEDIA])
1270 		return -EINVAL;
1271 
1272 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1273 					  info->attrs[TIPC_NLA_MEDIA],
1274 					  tipc_nl_media_policy, info->extack);
1275 	if (err)
1276 		return err;
1277 
1278 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1279 		return -EINVAL;
1280 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1281 
1282 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1283 	if (!rep)
1284 		return -ENOMEM;
1285 
1286 	msg.skb = rep;
1287 	msg.portid = info->snd_portid;
1288 	msg.seq = info->snd_seq;
1289 
1290 	rtnl_lock();
1291 	media = tipc_media_find(name);
1292 	if (!media) {
1293 		NL_SET_ERR_MSG(info->extack, "Media not found");
1294 		err = -EINVAL;
1295 		goto err_out;
1296 	}
1297 
1298 	err = __tipc_nl_add_media(&msg, media, 0);
1299 	if (err)
1300 		goto err_out;
1301 	rtnl_unlock();
1302 
1303 	return genlmsg_reply(rep, info);
1304 err_out:
1305 	rtnl_unlock();
1306 	nlmsg_free(rep);
1307 
1308 	return err;
1309 }
1310 
1311 int __tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1312 {
1313 	int err;
1314 	char *name;
1315 	struct tipc_media *m;
1316 	struct nlattr *attrs[TIPC_NLA_MEDIA_MAX + 1];
1317 
1318 	if (!info->attrs[TIPC_NLA_MEDIA])
1319 		return -EINVAL;
1320 
1321 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
1322 					  info->attrs[TIPC_NLA_MEDIA],
1323 					  tipc_nl_media_policy, info->extack);
1324 
1325 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1326 		return -EINVAL;
1327 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1328 
1329 	m = tipc_media_find(name);
1330 	if (!m) {
1331 		NL_SET_ERR_MSG(info->extack, "Media not found");
1332 		return -EINVAL;
1333 	}
1334 	if (attrs[TIPC_NLA_MEDIA_PROP]) {
1335 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1336 
1337 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_MEDIA_PROP],
1338 					      props);
1339 		if (err)
1340 			return err;
1341 
1342 		if (props[TIPC_NLA_PROP_TOL])
1343 			m->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1344 		if (props[TIPC_NLA_PROP_PRIO])
1345 			m->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1346 		if (props[TIPC_NLA_PROP_WIN])
1347 			m->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1348 		if (props[TIPC_NLA_PROP_MTU]) {
1349 			if (m->type_id != TIPC_MEDIA_TYPE_UDP) {
1350 				NL_SET_ERR_MSG(info->extack,
1351 					       "MTU property is unsupported");
1352 				return -EINVAL;
1353 			}
1354 #ifdef CONFIG_TIPC_MEDIA_UDP
1355 			if (tipc_udp_mtu_bad(nla_get_u32
1356 					     (props[TIPC_NLA_PROP_MTU]))) {
1357 				NL_SET_ERR_MSG(info->extack,
1358 					       "MTU value is out-of-range");
1359 				return -EINVAL;
1360 			}
1361 			m->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
1362 #endif
1363 		}
1364 	}
1365 
1366 	return 0;
1367 }
1368 
1369 int tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1370 {
1371 	int err;
1372 
1373 	rtnl_lock();
1374 	err = __tipc_nl_media_set(skb, info);
1375 	rtnl_unlock();
1376 
1377 	return err;
1378 }
1379