xref: /linux/net/tipc/bearer.c (revision 26b433d0da062d6e19d75350c0171d3cf8ff560d)
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 
47 #define MAX_ADDR_STR 60
48 
49 static struct tipc_media * const media_info_array[] = {
50 	&eth_media_info,
51 #ifdef CONFIG_TIPC_MEDIA_IB
52 	&ib_media_info,
53 #endif
54 #ifdef CONFIG_TIPC_MEDIA_UDP
55 	&udp_media_info,
56 #endif
57 	NULL
58 };
59 
60 static struct tipc_bearer *bearer_get(struct net *net, int bearer_id)
61 {
62 	struct tipc_net *tn = tipc_net(net);
63 
64 	return rcu_dereference_rtnl(tn->bearer_list[bearer_id]);
65 }
66 
67 static void bearer_disable(struct net *net, struct tipc_bearer *b);
68 static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
69 			   struct packet_type *pt, struct net_device *orig_dev);
70 
71 /**
72  * tipc_media_find - locates specified media object by name
73  */
74 struct tipc_media *tipc_media_find(const char *name)
75 {
76 	u32 i;
77 
78 	for (i = 0; media_info_array[i] != NULL; i++) {
79 		if (!strcmp(media_info_array[i]->name, name))
80 			break;
81 	}
82 	return media_info_array[i];
83 }
84 
85 /**
86  * media_find_id - locates specified media object by type identifier
87  */
88 static struct tipc_media *media_find_id(u8 type)
89 {
90 	u32 i;
91 
92 	for (i = 0; media_info_array[i] != NULL; i++) {
93 		if (media_info_array[i]->type_id == type)
94 			break;
95 	}
96 	return media_info_array[i];
97 }
98 
99 /**
100  * tipc_media_addr_printf - record media address in print buffer
101  */
102 void tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a)
103 {
104 	char addr_str[MAX_ADDR_STR];
105 	struct tipc_media *m;
106 	int ret;
107 
108 	m = media_find_id(a->media_id);
109 
110 	if (m && !m->addr2str(a, addr_str, sizeof(addr_str)))
111 		ret = scnprintf(buf, len, "%s(%s)", m->name, addr_str);
112 	else {
113 		u32 i;
114 
115 		ret = scnprintf(buf, len, "UNKNOWN(%u)", a->media_id);
116 		for (i = 0; i < sizeof(a->value); i++)
117 			ret += scnprintf(buf - ret, len + ret,
118 					    "-%02x", a->value[i]);
119 	}
120 }
121 
122 /**
123  * bearer_name_validate - validate & (optionally) deconstruct bearer name
124  * @name: ptr to bearer name string
125  * @name_parts: ptr to area for bearer name components (or NULL if not needed)
126  *
127  * Returns 1 if bearer name is valid, otherwise 0.
128  */
129 static int bearer_name_validate(const char *name,
130 				struct tipc_bearer_names *name_parts)
131 {
132 	char name_copy[TIPC_MAX_BEARER_NAME];
133 	char *media_name;
134 	char *if_name;
135 	u32 media_len;
136 	u32 if_len;
137 
138 	/* copy bearer name & ensure length is OK */
139 	name_copy[TIPC_MAX_BEARER_NAME - 1] = 0;
140 	/* need above in case non-Posix strncpy() doesn't pad with nulls */
141 	strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
142 	if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0)
143 		return 0;
144 
145 	/* ensure all component parts of bearer name are present */
146 	media_name = name_copy;
147 	if_name = strchr(media_name, ':');
148 	if (if_name == NULL)
149 		return 0;
150 	*(if_name++) = 0;
151 	media_len = if_name - media_name;
152 	if_len = strlen(if_name) + 1;
153 
154 	/* validate component parts of bearer name */
155 	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
156 	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
157 		return 0;
158 
159 	/* return bearer name components, if necessary */
160 	if (name_parts) {
161 		strcpy(name_parts->media_name, media_name);
162 		strcpy(name_parts->if_name, if_name);
163 	}
164 	return 1;
165 }
166 
167 /**
168  * tipc_bearer_find - locates bearer object with matching bearer name
169  */
170 struct tipc_bearer *tipc_bearer_find(struct net *net, const char *name)
171 {
172 	struct tipc_net *tn = net_generic(net, tipc_net_id);
173 	struct tipc_bearer *b;
174 	u32 i;
175 
176 	for (i = 0; i < MAX_BEARERS; i++) {
177 		b = rtnl_dereference(tn->bearer_list[i]);
178 		if (b && (!strcmp(b->name, name)))
179 			return b;
180 	}
181 	return NULL;
182 }
183 
184 /*     tipc_bearer_get_name - get the bearer name from its id.
185  *     @net: network namespace
186  *     @name: a pointer to the buffer where the name will be stored.
187  *     @bearer_id: the id to get the name from.
188  */
189 int tipc_bearer_get_name(struct net *net, char *name, u32 bearer_id)
190 {
191 	struct tipc_net *tn = tipc_net(net);
192 	struct tipc_bearer *b;
193 
194 	if (bearer_id >= MAX_BEARERS)
195 		return -EINVAL;
196 
197 	b = rtnl_dereference(tn->bearer_list[bearer_id]);
198 	if (!b)
199 		return -EINVAL;
200 
201 	strcpy(name, b->name);
202 	return 0;
203 }
204 
205 void tipc_bearer_add_dest(struct net *net, u32 bearer_id, u32 dest)
206 {
207 	struct tipc_net *tn = net_generic(net, tipc_net_id);
208 	struct tipc_bearer *b;
209 
210 	rcu_read_lock();
211 	b = rcu_dereference_rtnl(tn->bearer_list[bearer_id]);
212 	if (b)
213 		tipc_disc_add_dest(b->link_req);
214 	rcu_read_unlock();
215 }
216 
217 void tipc_bearer_remove_dest(struct net *net, u32 bearer_id, u32 dest)
218 {
219 	struct tipc_net *tn = net_generic(net, tipc_net_id);
220 	struct tipc_bearer *b;
221 
222 	rcu_read_lock();
223 	b = rcu_dereference_rtnl(tn->bearer_list[bearer_id]);
224 	if (b)
225 		tipc_disc_remove_dest(b->link_req);
226 	rcu_read_unlock();
227 }
228 
229 /**
230  * tipc_enable_bearer - enable bearer with the given name
231  */
232 static int tipc_enable_bearer(struct net *net, const char *name,
233 			      u32 disc_domain, u32 priority,
234 			      struct nlattr *attr[])
235 {
236 	struct tipc_net *tn = net_generic(net, tipc_net_id);
237 	struct tipc_bearer *b;
238 	struct tipc_media *m;
239 	struct tipc_bearer_names b_names;
240 	struct sk_buff *skb;
241 	char addr_string[16];
242 	u32 bearer_id;
243 	u32 with_this_prio;
244 	u32 i;
245 	int res = -EINVAL;
246 
247 	if (!tn->own_addr) {
248 		pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
249 			name);
250 		return -ENOPROTOOPT;
251 	}
252 	if (!bearer_name_validate(name, &b_names)) {
253 		pr_warn("Bearer <%s> rejected, illegal name\n", name);
254 		return -EINVAL;
255 	}
256 	if (tipc_addr_domain_valid(disc_domain) &&
257 	    (disc_domain != tn->own_addr)) {
258 		if (tipc_in_scope(disc_domain, tn->own_addr)) {
259 			disc_domain = tn->own_addr & TIPC_ZONE_CLUSTER_MASK;
260 			res = 0;   /* accept any node in own cluster */
261 		} else if (in_own_cluster_exact(net, disc_domain))
262 			res = 0;   /* accept specified node in own cluster */
263 	}
264 	if (res) {
265 		pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
266 			name);
267 		return -EINVAL;
268 	}
269 	if ((priority > TIPC_MAX_LINK_PRI) &&
270 	    (priority != TIPC_MEDIA_LINK_PRI)) {
271 		pr_warn("Bearer <%s> rejected, illegal priority\n", name);
272 		return -EINVAL;
273 	}
274 
275 	m = tipc_media_find(b_names.media_name);
276 	if (!m) {
277 		pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
278 			name, b_names.media_name);
279 		return -EINVAL;
280 	}
281 
282 	if (priority == TIPC_MEDIA_LINK_PRI)
283 		priority = m->priority;
284 
285 restart:
286 	bearer_id = MAX_BEARERS;
287 	with_this_prio = 1;
288 	for (i = MAX_BEARERS; i-- != 0; ) {
289 		b = rtnl_dereference(tn->bearer_list[i]);
290 		if (!b) {
291 			bearer_id = i;
292 			continue;
293 		}
294 		if (!strcmp(name, b->name)) {
295 			pr_warn("Bearer <%s> rejected, already enabled\n",
296 				name);
297 			return -EINVAL;
298 		}
299 		if ((b->priority == priority) &&
300 		    (++with_this_prio > 2)) {
301 			if (priority-- == 0) {
302 				pr_warn("Bearer <%s> rejected, duplicate priority\n",
303 					name);
304 				return -EINVAL;
305 			}
306 			pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
307 				name, priority + 1, priority);
308 			goto restart;
309 		}
310 	}
311 	if (bearer_id >= MAX_BEARERS) {
312 		pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
313 			name, MAX_BEARERS);
314 		return -EINVAL;
315 	}
316 
317 	b = kzalloc(sizeof(*b), GFP_ATOMIC);
318 	if (!b)
319 		return -ENOMEM;
320 
321 	strcpy(b->name, name);
322 	b->media = m;
323 	res = m->enable_media(net, b, attr);
324 	if (res) {
325 		pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
326 			name, -res);
327 		return -EINVAL;
328 	}
329 
330 	b->identity = bearer_id;
331 	b->tolerance = m->tolerance;
332 	b->window = m->window;
333 	b->domain = disc_domain;
334 	b->net_plane = bearer_id + 'A';
335 	b->priority = priority;
336 	test_and_set_bit_lock(0, &b->up);
337 
338 	res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
339 	if (res) {
340 		bearer_disable(net, b);
341 		pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
342 			name);
343 		return -EINVAL;
344 	}
345 
346 	rcu_assign_pointer(tn->bearer_list[bearer_id], b);
347 	if (skb)
348 		tipc_bearer_xmit_skb(net, bearer_id, skb, &b->bcast_addr);
349 
350 	if (tipc_mon_create(net, bearer_id))
351 		return -ENOMEM;
352 
353 	pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
354 		name,
355 		tipc_addr_string_fill(addr_string, disc_domain), priority);
356 	return res;
357 }
358 
359 /**
360  * tipc_reset_bearer - Reset all links established over this bearer
361  */
362 static int tipc_reset_bearer(struct net *net, struct tipc_bearer *b)
363 {
364 	pr_info("Resetting bearer <%s>\n", b->name);
365 	tipc_node_delete_links(net, b->identity);
366 	tipc_disc_reset(net, b);
367 	return 0;
368 }
369 
370 /* tipc_bearer_reset_all - reset all links on all bearers
371  */
372 void tipc_bearer_reset_all(struct net *net)
373 {
374 	struct tipc_bearer *b;
375 	int i;
376 
377 	for (i = 0; i < MAX_BEARERS; i++) {
378 		b = bearer_get(net, i);
379 		if (b)
380 			clear_bit_unlock(0, &b->up);
381 	}
382 	for (i = 0; i < MAX_BEARERS; i++) {
383 		b = bearer_get(net, i);
384 		if (b)
385 			tipc_reset_bearer(net, b);
386 	}
387 	for (i = 0; i < MAX_BEARERS; i++) {
388 		b = bearer_get(net, i);
389 		if (b)
390 			test_and_set_bit_lock(0, &b->up);
391 	}
392 }
393 
394 /**
395  * bearer_disable
396  *
397  * Note: This routine assumes caller holds RTNL lock.
398  */
399 static void bearer_disable(struct net *net, struct tipc_bearer *b)
400 {
401 	struct tipc_net *tn = tipc_net(net);
402 	int bearer_id = b->identity;
403 
404 	pr_info("Disabling bearer <%s>\n", b->name);
405 	clear_bit_unlock(0, &b->up);
406 	tipc_node_delete_links(net, bearer_id);
407 	b->media->disable_media(b);
408 	RCU_INIT_POINTER(b->media_ptr, NULL);
409 	if (b->link_req)
410 		tipc_disc_delete(b->link_req);
411 	RCU_INIT_POINTER(tn->bearer_list[bearer_id], NULL);
412 	kfree_rcu(b, rcu);
413 	tipc_mon_delete(net, bearer_id);
414 }
415 
416 int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
417 			 struct nlattr *attr[])
418 {
419 	struct net_device *dev;
420 	char *driver_name = strchr((const char *)b->name, ':') + 1;
421 
422 	/* Find device with specified name */
423 	dev = dev_get_by_name(net, driver_name);
424 	if (!dev)
425 		return -ENODEV;
426 	if (tipc_mtu_bad(dev, 0)) {
427 		dev_put(dev);
428 		return -EINVAL;
429 	}
430 
431 	/* Associate TIPC bearer with L2 bearer */
432 	rcu_assign_pointer(b->media_ptr, dev);
433 	b->pt.dev = dev;
434 	b->pt.type = htons(ETH_P_TIPC);
435 	b->pt.func = tipc_l2_rcv_msg;
436 	dev_add_pack(&b->pt);
437 	memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
438 	memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len);
439 	b->bcast_addr.media_id = b->media->type_id;
440 	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
441 	b->mtu = dev->mtu;
442 	b->media->raw2addr(b, &b->addr, (char *)dev->dev_addr);
443 	rcu_assign_pointer(dev->tipc_ptr, b);
444 	return 0;
445 }
446 
447 /* tipc_disable_l2_media - detach TIPC bearer from an L2 interface
448  *
449  * Mark L2 bearer as inactive so that incoming buffers are thrown away
450  */
451 void tipc_disable_l2_media(struct tipc_bearer *b)
452 {
453 	struct net_device *dev;
454 
455 	dev = (struct net_device *)rtnl_dereference(b->media_ptr);
456 	dev_remove_pack(&b->pt);
457 	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
458 	synchronize_net();
459 	dev_put(dev);
460 }
461 
462 /**
463  * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
464  * @skb: the packet to be sent
465  * @b: the bearer through which the packet is to be sent
466  * @dest: peer destination address
467  */
468 int tipc_l2_send_msg(struct net *net, struct sk_buff *skb,
469 		     struct tipc_bearer *b, struct tipc_media_addr *dest)
470 {
471 	struct net_device *dev;
472 	int delta;
473 
474 	dev = (struct net_device *)rcu_dereference_rtnl(b->media_ptr);
475 	if (!dev)
476 		return 0;
477 
478 	delta = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
479 	if ((delta > 0) && pskb_expand_head(skb, delta, 0, GFP_ATOMIC)) {
480 		kfree_skb(skb);
481 		return 0;
482 	}
483 	skb_reset_network_header(skb);
484 	skb->dev = dev;
485 	skb->protocol = htons(ETH_P_TIPC);
486 	dev_hard_header(skb, dev, ETH_P_TIPC, dest->value,
487 			dev->dev_addr, skb->len);
488 	dev_queue_xmit(skb);
489 	return 0;
490 }
491 
492 bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id)
493 {
494 	bool supp = false;
495 	struct tipc_bearer *b;
496 
497 	rcu_read_lock();
498 	b = bearer_get(net, bearer_id);
499 	if (b)
500 		supp = (b->bcast_addr.broadcast == TIPC_BROADCAST_SUPPORT);
501 	rcu_read_unlock();
502 	return supp;
503 }
504 
505 int tipc_bearer_mtu(struct net *net, u32 bearer_id)
506 {
507 	int mtu = 0;
508 	struct tipc_bearer *b;
509 
510 	rcu_read_lock();
511 	b = rcu_dereference_rtnl(tipc_net(net)->bearer_list[bearer_id]);
512 	if (b)
513 		mtu = b->mtu;
514 	rcu_read_unlock();
515 	return mtu;
516 }
517 
518 /* tipc_bearer_xmit_skb - sends buffer to destination over bearer
519  */
520 void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
521 			  struct sk_buff *skb,
522 			  struct tipc_media_addr *dest)
523 {
524 	struct tipc_msg *hdr = buf_msg(skb);
525 	struct tipc_bearer *b;
526 
527 	rcu_read_lock();
528 	b = bearer_get(net, bearer_id);
529 	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr))))
530 		b->media->send_msg(net, skb, b, dest);
531 	else
532 		kfree_skb(skb);
533 	rcu_read_unlock();
534 }
535 
536 /* tipc_bearer_xmit() -send buffer to destination over bearer
537  */
538 void tipc_bearer_xmit(struct net *net, u32 bearer_id,
539 		      struct sk_buff_head *xmitq,
540 		      struct tipc_media_addr *dst)
541 {
542 	struct tipc_bearer *b;
543 	struct sk_buff *skb, *tmp;
544 
545 	if (skb_queue_empty(xmitq))
546 		return;
547 
548 	rcu_read_lock();
549 	b = bearer_get(net, bearer_id);
550 	if (unlikely(!b))
551 		__skb_queue_purge(xmitq);
552 	skb_queue_walk_safe(xmitq, skb, tmp) {
553 		__skb_dequeue(xmitq);
554 		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb))))
555 			b->media->send_msg(net, skb, b, dst);
556 		else
557 			kfree_skb(skb);
558 	}
559 	rcu_read_unlock();
560 }
561 
562 /* tipc_bearer_bc_xmit() - broadcast buffers to all destinations
563  */
564 void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
565 			 struct sk_buff_head *xmitq)
566 {
567 	struct tipc_net *tn = tipc_net(net);
568 	int net_id = tn->net_id;
569 	struct tipc_bearer *b;
570 	struct sk_buff *skb, *tmp;
571 	struct tipc_msg *hdr;
572 
573 	rcu_read_lock();
574 	b = bearer_get(net, bearer_id);
575 	if (unlikely(!b || !test_bit(0, &b->up)))
576 		__skb_queue_purge(xmitq);
577 	skb_queue_walk_safe(xmitq, skb, tmp) {
578 		hdr = buf_msg(skb);
579 		msg_set_non_seq(hdr, 1);
580 		msg_set_mc_netid(hdr, net_id);
581 		__skb_dequeue(xmitq);
582 		b->media->send_msg(net, skb, b, &b->bcast_addr);
583 	}
584 	rcu_read_unlock();
585 }
586 
587 /**
588  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
589  * @buf: the received packet
590  * @dev: the net device that the packet was received on
591  * @pt: the packet_type structure which was used to register this handler
592  * @orig_dev: the original receive net device in case the device is a bond
593  *
594  * Accept only packets explicitly sent to this node, or broadcast packets;
595  * ignores packets sent using interface multicast, and traffic sent to other
596  * nodes (which can happen if interface is running in promiscuous mode).
597  */
598 static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
599 			   struct packet_type *pt, struct net_device *orig_dev)
600 {
601 	struct tipc_bearer *b;
602 
603 	rcu_read_lock();
604 	b = rcu_dereference_rtnl(dev->tipc_ptr) ?:
605 		rcu_dereference_rtnl(orig_dev->tipc_ptr);
606 	if (likely(b && test_bit(0, &b->up) &&
607 		   (skb->pkt_type <= PACKET_MULTICAST))) {
608 		skb->next = NULL;
609 		tipc_rcv(dev_net(b->pt.dev), skb, b);
610 		rcu_read_unlock();
611 		return NET_RX_SUCCESS;
612 	}
613 	rcu_read_unlock();
614 	kfree_skb(skb);
615 	return NET_RX_DROP;
616 }
617 
618 /**
619  * tipc_l2_device_event - handle device events from network device
620  * @nb: the context of the notification
621  * @evt: the type of event
622  * @ptr: the net device that the event was on
623  *
624  * This function is called by the Ethernet driver in case of link
625  * change event.
626  */
627 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
628 				void *ptr)
629 {
630 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
631 	struct net *net = dev_net(dev);
632 	struct tipc_bearer *b;
633 
634 	b = rtnl_dereference(dev->tipc_ptr);
635 	if (!b)
636 		return NOTIFY_DONE;
637 
638 	switch (evt) {
639 	case NETDEV_CHANGE:
640 		if (netif_carrier_ok(dev))
641 			break;
642 	case NETDEV_UP:
643 		test_and_set_bit_lock(0, &b->up);
644 		break;
645 	case NETDEV_GOING_DOWN:
646 		clear_bit_unlock(0, &b->up);
647 		tipc_reset_bearer(net, b);
648 		break;
649 	case NETDEV_CHANGEMTU:
650 		if (tipc_mtu_bad(dev, 0)) {
651 			bearer_disable(net, b);
652 			break;
653 		}
654 		b->mtu = dev->mtu;
655 		tipc_reset_bearer(net, b);
656 		break;
657 	case NETDEV_CHANGEADDR:
658 		b->media->raw2addr(b, &b->addr,
659 				   (char *)dev->dev_addr);
660 		tipc_reset_bearer(net, b);
661 		break;
662 	case NETDEV_UNREGISTER:
663 	case NETDEV_CHANGENAME:
664 		bearer_disable(dev_net(dev), b);
665 		break;
666 	}
667 	return NOTIFY_OK;
668 }
669 
670 static struct notifier_block notifier = {
671 	.notifier_call  = tipc_l2_device_event,
672 	.priority	= 0,
673 };
674 
675 int tipc_bearer_setup(void)
676 {
677 	return register_netdevice_notifier(&notifier);
678 }
679 
680 void tipc_bearer_cleanup(void)
681 {
682 	unregister_netdevice_notifier(&notifier);
683 }
684 
685 void tipc_bearer_stop(struct net *net)
686 {
687 	struct tipc_net *tn = net_generic(net, tipc_net_id);
688 	struct tipc_bearer *b;
689 	u32 i;
690 
691 	for (i = 0; i < MAX_BEARERS; i++) {
692 		b = rtnl_dereference(tn->bearer_list[i]);
693 		if (b) {
694 			bearer_disable(net, b);
695 			tn->bearer_list[i] = NULL;
696 		}
697 	}
698 }
699 
700 /* Caller should hold rtnl_lock to protect the bearer */
701 static int __tipc_nl_add_bearer(struct tipc_nl_msg *msg,
702 				struct tipc_bearer *bearer, int nlflags)
703 {
704 	void *hdr;
705 	struct nlattr *attrs;
706 	struct nlattr *prop;
707 
708 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
709 			  nlflags, TIPC_NL_BEARER_GET);
710 	if (!hdr)
711 		return -EMSGSIZE;
712 
713 	attrs = nla_nest_start(msg->skb, TIPC_NLA_BEARER);
714 	if (!attrs)
715 		goto msg_full;
716 
717 	if (nla_put_string(msg->skb, TIPC_NLA_BEARER_NAME, bearer->name))
718 		goto attr_msg_full;
719 
720 	prop = nla_nest_start(msg->skb, TIPC_NLA_BEARER_PROP);
721 	if (!prop)
722 		goto prop_msg_full;
723 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, bearer->priority))
724 		goto prop_msg_full;
725 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, bearer->tolerance))
726 		goto prop_msg_full;
727 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bearer->window))
728 		goto prop_msg_full;
729 
730 	nla_nest_end(msg->skb, prop);
731 
732 #ifdef CONFIG_TIPC_MEDIA_UDP
733 	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP) {
734 		if (tipc_udp_nl_add_bearer_data(msg, bearer))
735 			goto attr_msg_full;
736 	}
737 #endif
738 
739 	nla_nest_end(msg->skb, attrs);
740 	genlmsg_end(msg->skb, hdr);
741 
742 	return 0;
743 
744 prop_msg_full:
745 	nla_nest_cancel(msg->skb, prop);
746 attr_msg_full:
747 	nla_nest_cancel(msg->skb, attrs);
748 msg_full:
749 	genlmsg_cancel(msg->skb, hdr);
750 
751 	return -EMSGSIZE;
752 }
753 
754 int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb)
755 {
756 	int err;
757 	int i = cb->args[0];
758 	struct tipc_bearer *bearer;
759 	struct tipc_nl_msg msg;
760 	struct net *net = sock_net(skb->sk);
761 	struct tipc_net *tn = net_generic(net, tipc_net_id);
762 
763 	if (i == MAX_BEARERS)
764 		return 0;
765 
766 	msg.skb = skb;
767 	msg.portid = NETLINK_CB(cb->skb).portid;
768 	msg.seq = cb->nlh->nlmsg_seq;
769 
770 	rtnl_lock();
771 	for (i = 0; i < MAX_BEARERS; i++) {
772 		bearer = rtnl_dereference(tn->bearer_list[i]);
773 		if (!bearer)
774 			continue;
775 
776 		err = __tipc_nl_add_bearer(&msg, bearer, NLM_F_MULTI);
777 		if (err)
778 			break;
779 	}
780 	rtnl_unlock();
781 
782 	cb->args[0] = i;
783 	return skb->len;
784 }
785 
786 int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info)
787 {
788 	int err;
789 	char *name;
790 	struct sk_buff *rep;
791 	struct tipc_bearer *bearer;
792 	struct tipc_nl_msg msg;
793 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
794 	struct net *net = genl_info_net(info);
795 
796 	if (!info->attrs[TIPC_NLA_BEARER])
797 		return -EINVAL;
798 
799 	err = nla_parse_nested(attrs, TIPC_NLA_BEARER_MAX,
800 			       info->attrs[TIPC_NLA_BEARER],
801 			       tipc_nl_bearer_policy, info->extack);
802 	if (err)
803 		return err;
804 
805 	if (!attrs[TIPC_NLA_BEARER_NAME])
806 		return -EINVAL;
807 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
808 
809 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
810 	if (!rep)
811 		return -ENOMEM;
812 
813 	msg.skb = rep;
814 	msg.portid = info->snd_portid;
815 	msg.seq = info->snd_seq;
816 
817 	rtnl_lock();
818 	bearer = tipc_bearer_find(net, name);
819 	if (!bearer) {
820 		err = -EINVAL;
821 		goto err_out;
822 	}
823 
824 	err = __tipc_nl_add_bearer(&msg, bearer, 0);
825 	if (err)
826 		goto err_out;
827 	rtnl_unlock();
828 
829 	return genlmsg_reply(rep, info);
830 err_out:
831 	rtnl_unlock();
832 	nlmsg_free(rep);
833 
834 	return err;
835 }
836 
837 int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
838 {
839 	int err;
840 	char *name;
841 	struct tipc_bearer *bearer;
842 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
843 	struct net *net = sock_net(skb->sk);
844 
845 	if (!info->attrs[TIPC_NLA_BEARER])
846 		return -EINVAL;
847 
848 	err = nla_parse_nested(attrs, TIPC_NLA_BEARER_MAX,
849 			       info->attrs[TIPC_NLA_BEARER],
850 			       tipc_nl_bearer_policy, info->extack);
851 	if (err)
852 		return err;
853 
854 	if (!attrs[TIPC_NLA_BEARER_NAME])
855 		return -EINVAL;
856 
857 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
858 
859 	rtnl_lock();
860 	bearer = tipc_bearer_find(net, name);
861 	if (!bearer) {
862 		rtnl_unlock();
863 		return -EINVAL;
864 	}
865 
866 	bearer_disable(net, bearer);
867 	rtnl_unlock();
868 
869 	return 0;
870 }
871 
872 int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
873 {
874 	int err;
875 	char *bearer;
876 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
877 	struct net *net = sock_net(skb->sk);
878 	struct tipc_net *tn = net_generic(net, tipc_net_id);
879 	u32 domain;
880 	u32 prio;
881 
882 	prio = TIPC_MEDIA_LINK_PRI;
883 	domain = tn->own_addr & TIPC_ZONE_CLUSTER_MASK;
884 
885 	if (!info->attrs[TIPC_NLA_BEARER])
886 		return -EINVAL;
887 
888 	err = nla_parse_nested(attrs, TIPC_NLA_BEARER_MAX,
889 			       info->attrs[TIPC_NLA_BEARER],
890 			       tipc_nl_bearer_policy, info->extack);
891 	if (err)
892 		return err;
893 
894 	if (!attrs[TIPC_NLA_BEARER_NAME])
895 		return -EINVAL;
896 
897 	bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
898 
899 	if (attrs[TIPC_NLA_BEARER_DOMAIN])
900 		domain = nla_get_u32(attrs[TIPC_NLA_BEARER_DOMAIN]);
901 
902 	if (attrs[TIPC_NLA_BEARER_PROP]) {
903 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
904 
905 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
906 					      props);
907 		if (err)
908 			return err;
909 
910 		if (props[TIPC_NLA_PROP_PRIO])
911 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
912 	}
913 
914 	rtnl_lock();
915 	err = tipc_enable_bearer(net, bearer, domain, prio, attrs);
916 	if (err) {
917 		rtnl_unlock();
918 		return err;
919 	}
920 	rtnl_unlock();
921 
922 	return 0;
923 }
924 
925 int tipc_nl_bearer_add(struct sk_buff *skb, struct genl_info *info)
926 {
927 	int err;
928 	char *name;
929 	struct tipc_bearer *b;
930 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
931 	struct net *net = sock_net(skb->sk);
932 
933 	if (!info->attrs[TIPC_NLA_BEARER])
934 		return -EINVAL;
935 
936 	err = nla_parse_nested(attrs, TIPC_NLA_BEARER_MAX,
937 			       info->attrs[TIPC_NLA_BEARER],
938 			       tipc_nl_bearer_policy, info->extack);
939 	if (err)
940 		return err;
941 
942 	if (!attrs[TIPC_NLA_BEARER_NAME])
943 		return -EINVAL;
944 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
945 
946 	rtnl_lock();
947 	b = tipc_bearer_find(net, name);
948 	if (!b) {
949 		rtnl_unlock();
950 		return -EINVAL;
951 	}
952 
953 #ifdef CONFIG_TIPC_MEDIA_UDP
954 	if (attrs[TIPC_NLA_BEARER_UDP_OPTS]) {
955 		err = tipc_udp_nl_bearer_add(b,
956 					     attrs[TIPC_NLA_BEARER_UDP_OPTS]);
957 		if (err) {
958 			rtnl_unlock();
959 			return err;
960 		}
961 	}
962 #endif
963 	rtnl_unlock();
964 
965 	return 0;
966 }
967 
968 int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
969 {
970 	int err;
971 	char *name;
972 	struct tipc_bearer *b;
973 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
974 	struct net *net = sock_net(skb->sk);
975 
976 	if (!info->attrs[TIPC_NLA_BEARER])
977 		return -EINVAL;
978 
979 	err = nla_parse_nested(attrs, TIPC_NLA_BEARER_MAX,
980 			       info->attrs[TIPC_NLA_BEARER],
981 			       tipc_nl_bearer_policy, info->extack);
982 	if (err)
983 		return err;
984 
985 	if (!attrs[TIPC_NLA_BEARER_NAME])
986 		return -EINVAL;
987 	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
988 
989 	rtnl_lock();
990 	b = tipc_bearer_find(net, name);
991 	if (!b) {
992 		rtnl_unlock();
993 		return -EINVAL;
994 	}
995 
996 	if (attrs[TIPC_NLA_BEARER_PROP]) {
997 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
998 
999 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
1000 					      props);
1001 		if (err) {
1002 			rtnl_unlock();
1003 			return err;
1004 		}
1005 
1006 		if (props[TIPC_NLA_PROP_TOL])
1007 			b->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1008 		if (props[TIPC_NLA_PROP_PRIO])
1009 			b->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1010 		if (props[TIPC_NLA_PROP_WIN])
1011 			b->window = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1012 	}
1013 	rtnl_unlock();
1014 
1015 	return 0;
1016 }
1017 
1018 static int __tipc_nl_add_media(struct tipc_nl_msg *msg,
1019 			       struct tipc_media *media, int nlflags)
1020 {
1021 	void *hdr;
1022 	struct nlattr *attrs;
1023 	struct nlattr *prop;
1024 
1025 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1026 			  nlflags, TIPC_NL_MEDIA_GET);
1027 	if (!hdr)
1028 		return -EMSGSIZE;
1029 
1030 	attrs = nla_nest_start(msg->skb, TIPC_NLA_MEDIA);
1031 	if (!attrs)
1032 		goto msg_full;
1033 
1034 	if (nla_put_string(msg->skb, TIPC_NLA_MEDIA_NAME, media->name))
1035 		goto attr_msg_full;
1036 
1037 	prop = nla_nest_start(msg->skb, TIPC_NLA_MEDIA_PROP);
1038 	if (!prop)
1039 		goto prop_msg_full;
1040 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, media->priority))
1041 		goto prop_msg_full;
1042 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, media->tolerance))
1043 		goto prop_msg_full;
1044 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, media->window))
1045 		goto prop_msg_full;
1046 
1047 	nla_nest_end(msg->skb, prop);
1048 	nla_nest_end(msg->skb, attrs);
1049 	genlmsg_end(msg->skb, hdr);
1050 
1051 	return 0;
1052 
1053 prop_msg_full:
1054 	nla_nest_cancel(msg->skb, prop);
1055 attr_msg_full:
1056 	nla_nest_cancel(msg->skb, attrs);
1057 msg_full:
1058 	genlmsg_cancel(msg->skb, hdr);
1059 
1060 	return -EMSGSIZE;
1061 }
1062 
1063 int tipc_nl_media_dump(struct sk_buff *skb, struct netlink_callback *cb)
1064 {
1065 	int err;
1066 	int i = cb->args[0];
1067 	struct tipc_nl_msg msg;
1068 
1069 	if (i == MAX_MEDIA)
1070 		return 0;
1071 
1072 	msg.skb = skb;
1073 	msg.portid = NETLINK_CB(cb->skb).portid;
1074 	msg.seq = cb->nlh->nlmsg_seq;
1075 
1076 	rtnl_lock();
1077 	for (; media_info_array[i] != NULL; i++) {
1078 		err = __tipc_nl_add_media(&msg, media_info_array[i],
1079 					  NLM_F_MULTI);
1080 		if (err)
1081 			break;
1082 	}
1083 	rtnl_unlock();
1084 
1085 	cb->args[0] = i;
1086 	return skb->len;
1087 }
1088 
1089 int tipc_nl_media_get(struct sk_buff *skb, struct genl_info *info)
1090 {
1091 	int err;
1092 	char *name;
1093 	struct tipc_nl_msg msg;
1094 	struct tipc_media *media;
1095 	struct sk_buff *rep;
1096 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1097 
1098 	if (!info->attrs[TIPC_NLA_MEDIA])
1099 		return -EINVAL;
1100 
1101 	err = nla_parse_nested(attrs, TIPC_NLA_MEDIA_MAX,
1102 			       info->attrs[TIPC_NLA_MEDIA],
1103 			       tipc_nl_media_policy, info->extack);
1104 	if (err)
1105 		return err;
1106 
1107 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1108 		return -EINVAL;
1109 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1110 
1111 	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1112 	if (!rep)
1113 		return -ENOMEM;
1114 
1115 	msg.skb = rep;
1116 	msg.portid = info->snd_portid;
1117 	msg.seq = info->snd_seq;
1118 
1119 	rtnl_lock();
1120 	media = tipc_media_find(name);
1121 	if (!media) {
1122 		err = -EINVAL;
1123 		goto err_out;
1124 	}
1125 
1126 	err = __tipc_nl_add_media(&msg, media, 0);
1127 	if (err)
1128 		goto err_out;
1129 	rtnl_unlock();
1130 
1131 	return genlmsg_reply(rep, info);
1132 err_out:
1133 	rtnl_unlock();
1134 	nlmsg_free(rep);
1135 
1136 	return err;
1137 }
1138 
1139 int tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
1140 {
1141 	int err;
1142 	char *name;
1143 	struct tipc_media *m;
1144 	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
1145 
1146 	if (!info->attrs[TIPC_NLA_MEDIA])
1147 		return -EINVAL;
1148 
1149 	err = nla_parse_nested(attrs, TIPC_NLA_MEDIA_MAX,
1150 			       info->attrs[TIPC_NLA_MEDIA],
1151 			       tipc_nl_media_policy, info->extack);
1152 
1153 	if (!attrs[TIPC_NLA_MEDIA_NAME])
1154 		return -EINVAL;
1155 	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
1156 
1157 	rtnl_lock();
1158 	m = tipc_media_find(name);
1159 	if (!m) {
1160 		rtnl_unlock();
1161 		return -EINVAL;
1162 	}
1163 
1164 	if (attrs[TIPC_NLA_MEDIA_PROP]) {
1165 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1166 
1167 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_MEDIA_PROP],
1168 					      props);
1169 		if (err) {
1170 			rtnl_unlock();
1171 			return err;
1172 		}
1173 
1174 		if (props[TIPC_NLA_PROP_TOL])
1175 			m->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1176 		if (props[TIPC_NLA_PROP_PRIO])
1177 			m->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1178 		if (props[TIPC_NLA_PROP_WIN])
1179 			m->window = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1180 	}
1181 	rtnl_unlock();
1182 
1183 	return 0;
1184 }
1185