xref: /linux/net/tipc/bearer.c (revision 00a6d7b6762c27d441e9ac8faff36384bc0fc180)
1 /*
2  * net/tipc/bearer.c: TIPC bearer code
3  *
4  * Copyright (c) 1996-2006, 2013, 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 "core.h"
38 #include "config.h"
39 #include "bearer.h"
40 #include "discover.h"
41 
42 #define MAX_ADDR_STR 60
43 
44 static struct tipc_media * const media_info_array[] = {
45 	&eth_media_info,
46 #ifdef CONFIG_TIPC_MEDIA_IB
47 	&ib_media_info,
48 #endif
49 	NULL
50 };
51 
52 struct tipc_bearer *bearer_list[MAX_BEARERS + 1];
53 
54 static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down);
55 
56 /**
57  * tipc_media_find - locates specified media object by name
58  */
59 struct tipc_media *tipc_media_find(const char *name)
60 {
61 	u32 i;
62 
63 	for (i = 0; media_info_array[i] != NULL; i++) {
64 		if (!strcmp(media_info_array[i]->name, name))
65 			break;
66 	}
67 	return media_info_array[i];
68 }
69 
70 /**
71  * media_find_id - locates specified media object by type identifier
72  */
73 static struct tipc_media *media_find_id(u8 type)
74 {
75 	u32 i;
76 
77 	for (i = 0; media_info_array[i] != NULL; i++) {
78 		if (media_info_array[i]->type_id == type)
79 			break;
80 	}
81 	return media_info_array[i];
82 }
83 
84 /**
85  * tipc_media_addr_printf - record media address in print buffer
86  */
87 void tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a)
88 {
89 	char addr_str[MAX_ADDR_STR];
90 	struct tipc_media *m_ptr;
91 	int ret;
92 
93 	m_ptr = media_find_id(a->media_id);
94 
95 	if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str)))
96 		ret = tipc_snprintf(buf, len, "%s(%s)", m_ptr->name, addr_str);
97 	else {
98 		u32 i;
99 
100 		ret = tipc_snprintf(buf, len, "UNKNOWN(%u)", a->media_id);
101 		for (i = 0; i < sizeof(a->value); i++)
102 			ret += tipc_snprintf(buf - ret, len + ret,
103 					    "-%02x", a->value[i]);
104 	}
105 }
106 
107 /**
108  * tipc_media_get_names - record names of registered media in buffer
109  */
110 struct sk_buff *tipc_media_get_names(void)
111 {
112 	struct sk_buff *buf;
113 	int i;
114 
115 	buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME));
116 	if (!buf)
117 		return NULL;
118 
119 	for (i = 0; media_info_array[i] != NULL; i++) {
120 		tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME,
121 				    media_info_array[i]->name,
122 				    strlen(media_info_array[i]->name) + 1);
123 	}
124 	return buf;
125 }
126 
127 /**
128  * bearer_name_validate - validate & (optionally) deconstruct bearer name
129  * @name: ptr to bearer name string
130  * @name_parts: ptr to area for bearer name components (or NULL if not needed)
131  *
132  * Returns 1 if bearer name is valid, otherwise 0.
133  */
134 static int bearer_name_validate(const char *name,
135 				struct tipc_bearer_names *name_parts)
136 {
137 	char name_copy[TIPC_MAX_BEARER_NAME];
138 	char *media_name;
139 	char *if_name;
140 	u32 media_len;
141 	u32 if_len;
142 
143 	/* copy bearer name & ensure length is OK */
144 	name_copy[TIPC_MAX_BEARER_NAME - 1] = 0;
145 	/* need above in case non-Posix strncpy() doesn't pad with nulls */
146 	strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
147 	if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0)
148 		return 0;
149 
150 	/* ensure all component parts of bearer name are present */
151 	media_name = name_copy;
152 	if_name = strchr(media_name, ':');
153 	if (if_name == NULL)
154 		return 0;
155 	*(if_name++) = 0;
156 	media_len = if_name - media_name;
157 	if_len = strlen(if_name) + 1;
158 
159 	/* validate component parts of bearer name */
160 	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
161 	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
162 		return 0;
163 
164 	/* return bearer name components, if necessary */
165 	if (name_parts) {
166 		strcpy(name_parts->media_name, media_name);
167 		strcpy(name_parts->if_name, if_name);
168 	}
169 	return 1;
170 }
171 
172 /**
173  * tipc_bearer_find - locates bearer object with matching bearer name
174  */
175 struct tipc_bearer *tipc_bearer_find(const char *name)
176 {
177 	struct tipc_bearer *b_ptr;
178 	u32 i;
179 
180 	for (i = 0; i < MAX_BEARERS; i++) {
181 		b_ptr = bearer_list[i];
182 		if (b_ptr && (!strcmp(b_ptr->name, name)))
183 			return b_ptr;
184 	}
185 	return NULL;
186 }
187 
188 /**
189  * tipc_bearer_get_names - record names of bearers in buffer
190  */
191 struct sk_buff *tipc_bearer_get_names(void)
192 {
193 	struct sk_buff *buf;
194 	struct tipc_bearer *b;
195 	int i, j;
196 
197 	buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME));
198 	if (!buf)
199 		return NULL;
200 
201 	read_lock_bh(&tipc_net_lock);
202 	for (i = 0; media_info_array[i] != NULL; i++) {
203 		for (j = 0; j < MAX_BEARERS; j++) {
204 			b = bearer_list[j];
205 			if (!b)
206 				continue;
207 			if (b->media == media_info_array[i]) {
208 				tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
209 						    b->name,
210 						    strlen(b->name) + 1);
211 			}
212 		}
213 	}
214 	read_unlock_bh(&tipc_net_lock);
215 	return buf;
216 }
217 
218 void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest)
219 {
220 	tipc_nmap_add(&b_ptr->nodes, dest);
221 	tipc_bcbearer_sort();
222 	tipc_disc_add_dest(b_ptr->link_req);
223 }
224 
225 void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest)
226 {
227 	tipc_nmap_remove(&b_ptr->nodes, dest);
228 	tipc_bcbearer_sort();
229 	tipc_disc_remove_dest(b_ptr->link_req);
230 }
231 
232 /**
233  * tipc_enable_bearer - enable bearer with the given name
234  */
235 int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority)
236 {
237 	struct tipc_bearer *b_ptr;
238 	struct tipc_media *m_ptr;
239 	struct tipc_bearer_names b_names;
240 	char addr_string[16];
241 	u32 bearer_id;
242 	u32 with_this_prio;
243 	u32 i;
244 	int res = -EINVAL;
245 
246 	if (!tipc_own_addr) {
247 		pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
248 			name);
249 		return -ENOPROTOOPT;
250 	}
251 	if (!bearer_name_validate(name, &b_names)) {
252 		pr_warn("Bearer <%s> rejected, illegal name\n", name);
253 		return -EINVAL;
254 	}
255 	if (tipc_addr_domain_valid(disc_domain) &&
256 	    (disc_domain != tipc_own_addr)) {
257 		if (tipc_in_scope(disc_domain, tipc_own_addr)) {
258 			disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK;
259 			res = 0;   /* accept any node in own cluster */
260 		} else if (in_own_cluster_exact(disc_domain))
261 			res = 0;   /* accept specified node in own cluster */
262 	}
263 	if (res) {
264 		pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
265 			name);
266 		return -EINVAL;
267 	}
268 	if ((priority > TIPC_MAX_LINK_PRI) &&
269 	    (priority != TIPC_MEDIA_LINK_PRI)) {
270 		pr_warn("Bearer <%s> rejected, illegal priority\n", name);
271 		return -EINVAL;
272 	}
273 
274 	write_lock_bh(&tipc_net_lock);
275 
276 	m_ptr = tipc_media_find(b_names.media_name);
277 	if (!m_ptr) {
278 		pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
279 			name, b_names.media_name);
280 		goto exit;
281 	}
282 
283 	if (priority == TIPC_MEDIA_LINK_PRI)
284 		priority = m_ptr->priority;
285 
286 restart:
287 	bearer_id = MAX_BEARERS;
288 	with_this_prio = 1;
289 	for (i = MAX_BEARERS; i-- != 0; ) {
290 		b_ptr = bearer_list[i];
291 		if (!b_ptr) {
292 			bearer_id = i;
293 			continue;
294 		}
295 		if (!strcmp(name, b_ptr->name)) {
296 			pr_warn("Bearer <%s> rejected, already enabled\n",
297 				name);
298 			goto exit;
299 		}
300 		if ((b_ptr->priority == priority) &&
301 		    (++with_this_prio > 2)) {
302 			if (priority-- == 0) {
303 				pr_warn("Bearer <%s> rejected, duplicate priority\n",
304 					name);
305 				goto exit;
306 			}
307 			pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
308 				name, priority + 1, priority);
309 			goto restart;
310 		}
311 	}
312 	if (bearer_id >= MAX_BEARERS) {
313 		pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
314 			name, MAX_BEARERS);
315 		goto exit;
316 	}
317 
318 	b_ptr = kzalloc(sizeof(*b_ptr), GFP_ATOMIC);
319 	if (!b_ptr) {
320 		res = -ENOMEM;
321 		goto exit;
322 	}
323 	strcpy(b_ptr->name, name);
324 	b_ptr->media = m_ptr;
325 	res = m_ptr->enable_media(b_ptr);
326 	if (res) {
327 		pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
328 			name, -res);
329 		goto exit;
330 	}
331 
332 	b_ptr->identity = bearer_id;
333 	b_ptr->tolerance = m_ptr->tolerance;
334 	b_ptr->window = m_ptr->window;
335 	b_ptr->domain = disc_domain;
336 	b_ptr->net_plane = bearer_id + 'A';
337 	b_ptr->priority = priority;
338 
339 	res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr);
340 	if (res) {
341 		bearer_disable(b_ptr, false);
342 		pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
343 			name);
344 		goto exit;
345 	}
346 
347 	bearer_list[bearer_id] = b_ptr;
348 
349 	pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
350 		name,
351 		tipc_addr_string_fill(addr_string, disc_domain), priority);
352 exit:
353 	write_unlock_bh(&tipc_net_lock);
354 	return res;
355 }
356 
357 /**
358  * tipc_reset_bearer - Reset all links established over this bearer
359  */
360 static int tipc_reset_bearer(struct tipc_bearer *b_ptr)
361 {
362 	read_lock_bh(&tipc_net_lock);
363 	pr_info("Resetting bearer <%s>\n", b_ptr->name);
364 	tipc_disc_delete(b_ptr->link_req);
365 	tipc_link_reset_list(b_ptr->identity);
366 	tipc_disc_create(b_ptr, &b_ptr->bcast_addr);
367 	read_unlock_bh(&tipc_net_lock);
368 	return 0;
369 }
370 
371 /**
372  * bearer_disable
373  *
374  * Note: This routine assumes caller holds tipc_net_lock.
375  */
376 static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down)
377 {
378 	u32 i;
379 
380 	pr_info("Disabling bearer <%s>\n", b_ptr->name);
381 	b_ptr->media->disable_media(b_ptr);
382 
383 	tipc_link_delete_list(b_ptr->identity, shutting_down);
384 	if (b_ptr->link_req)
385 		tipc_disc_delete(b_ptr->link_req);
386 
387 	for (i = 0; i < MAX_BEARERS; i++) {
388 		if (b_ptr == bearer_list[i]) {
389 			bearer_list[i] = NULL;
390 			break;
391 		}
392 	}
393 	kfree(b_ptr);
394 }
395 
396 int tipc_disable_bearer(const char *name)
397 {
398 	struct tipc_bearer *b_ptr;
399 	int res;
400 
401 	write_lock_bh(&tipc_net_lock);
402 	b_ptr = tipc_bearer_find(name);
403 	if (b_ptr == NULL) {
404 		pr_warn("Attempt to disable unknown bearer <%s>\n", name);
405 		res = -EINVAL;
406 	} else {
407 		bearer_disable(b_ptr, false);
408 		res = 0;
409 	}
410 	write_unlock_bh(&tipc_net_lock);
411 	return res;
412 }
413 
414 
415 /* tipc_l2_media_addr_set - initialize Ethernet media address structure
416  *
417  * Media-dependent "value" field stores MAC address in first 6 bytes
418  * and zeroes out the remaining bytes.
419  */
420 void tipc_l2_media_addr_set(const struct tipc_bearer *b,
421 			    struct tipc_media_addr *a, char *mac)
422 {
423 	int len = b->media->hwaddr_len;
424 
425 	if (unlikely(sizeof(a->value) < len)) {
426 		WARN_ONCE(1, "Media length invalid\n");
427 		return;
428 	}
429 
430 	memcpy(a->value, mac, len);
431 	memset(a->value + len, 0, sizeof(a->value) - len);
432 	a->media_id = b->media->type_id;
433 	a->broadcast = !memcmp(mac, b->bcast_addr.value, len);
434 }
435 
436 int tipc_enable_l2_media(struct tipc_bearer *b)
437 {
438 	struct net_device *dev;
439 	char *driver_name = strchr((const char *)b->name, ':') + 1;
440 
441 	/* Find device with specified name */
442 	dev = dev_get_by_name(&init_net, driver_name);
443 	if (!dev)
444 		return -ENODEV;
445 
446 	/* Associate TIPC bearer with Ethernet bearer */
447 	b->media_ptr = dev;
448 	memset(b->bcast_addr.value, 0, sizeof(b->bcast_addr.value));
449 	memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len);
450 	b->bcast_addr.media_id = b->media->type_id;
451 	b->bcast_addr.broadcast = 1;
452 	b->mtu = dev->mtu;
453 	tipc_l2_media_addr_set(b, &b->addr, (char *)dev->dev_addr);
454 	rcu_assign_pointer(dev->tipc_ptr, b);
455 	return 0;
456 }
457 
458 /* tipc_disable_l2_media - detach TIPC bearer from an Ethernet interface
459  *
460  * Mark Ethernet bearer as inactive so that incoming buffers are thrown away,
461  * then get worker thread to complete bearer cleanup.  (Can't do cleanup
462  * here because cleanup code needs to sleep and caller holds spinlocks.)
463  */
464 void tipc_disable_l2_media(struct tipc_bearer *b)
465 {
466 	struct net_device *dev = (struct net_device *)b->media_ptr;
467 	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
468 	dev_put(dev);
469 }
470 
471 /**
472  * tipc_l2_send_msg - send a TIPC packet out over an Ethernet interface
473  * @buf: the packet to be sent
474  * @b_ptr: the bearer through which the packet is to be sent
475  * @dest: peer destination address
476  */
477 int tipc_l2_send_msg(struct sk_buff *buf, struct tipc_bearer *b,
478 		     struct tipc_media_addr *dest)
479 {
480 	struct sk_buff *clone;
481 	int delta;
482 	struct net_device *dev = (struct net_device *)b->media_ptr;
483 
484 	clone = skb_clone(buf, GFP_ATOMIC);
485 	if (!clone)
486 		return 0;
487 
488 	delta = dev->hard_header_len - skb_headroom(buf);
489 	if ((delta > 0) &&
490 	    pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
491 		kfree_skb(clone);
492 		return 0;
493 	}
494 
495 	skb_reset_network_header(clone);
496 	clone->dev = dev;
497 	clone->protocol = htons(ETH_P_TIPC);
498 	dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
499 			dev->dev_addr, clone->len);
500 	dev_queue_xmit(clone);
501 	return 0;
502 }
503 
504 /* tipc_bearer_send- sends buffer to destination over bearer
505  *
506  * IMPORTANT:
507  * The media send routine must not alter the buffer being passed in
508  * as it may be needed for later retransmission!
509  */
510 void tipc_bearer_send(struct tipc_bearer *b, struct sk_buff *buf,
511 		      struct tipc_media_addr *dest)
512 {
513 	b->media->send_msg(buf, b, dest);
514 }
515 
516 /**
517  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
518  * @buf: the received packet
519  * @dev: the net device that the packet was received on
520  * @pt: the packet_type structure which was used to register this handler
521  * @orig_dev: the original receive net device in case the device is a bond
522  *
523  * Accept only packets explicitly sent to this node, or broadcast packets;
524  * ignores packets sent using interface multicast, and traffic sent to other
525  * nodes (which can happen if interface is running in promiscuous mode).
526  */
527 static int tipc_l2_rcv_msg(struct sk_buff *buf, struct net_device *dev,
528 			   struct packet_type *pt, struct net_device *orig_dev)
529 {
530 	struct tipc_bearer *b_ptr;
531 
532 	if (!net_eq(dev_net(dev), &init_net)) {
533 		kfree_skb(buf);
534 		return NET_RX_DROP;
535 	}
536 
537 	rcu_read_lock();
538 	b_ptr = rcu_dereference(dev->tipc_ptr);
539 	if (likely(b_ptr)) {
540 		if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
541 			buf->next = NULL;
542 			tipc_rcv(buf, b_ptr);
543 			rcu_read_unlock();
544 			return NET_RX_SUCCESS;
545 		}
546 	}
547 	rcu_read_unlock();
548 
549 	kfree_skb(buf);
550 	return NET_RX_DROP;
551 }
552 
553 /**
554  * tipc_l2_device_event - handle device events from network device
555  * @nb: the context of the notification
556  * @evt: the type of event
557  * @ptr: the net device that the event was on
558  *
559  * This function is called by the Ethernet driver in case of link
560  * change event.
561  */
562 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
563 				void *ptr)
564 {
565 	struct tipc_bearer *b_ptr;
566 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
567 
568 	if (!net_eq(dev_net(dev), &init_net))
569 		return NOTIFY_DONE;
570 
571 	rcu_read_lock();
572 	b_ptr = rcu_dereference(dev->tipc_ptr);
573 	if (!b_ptr) {
574 		rcu_read_unlock();
575 		return NOTIFY_DONE;
576 	}
577 
578 	b_ptr->mtu = dev->mtu;
579 
580 	switch (evt) {
581 	case NETDEV_CHANGE:
582 		if (netif_carrier_ok(dev))
583 			break;
584 	case NETDEV_DOWN:
585 	case NETDEV_CHANGEMTU:
586 		tipc_reset_bearer(b_ptr);
587 		break;
588 	case NETDEV_CHANGEADDR:
589 		tipc_l2_media_addr_set(b_ptr, &b_ptr->addr,
590 				       (char *)dev->dev_addr);
591 		tipc_reset_bearer(b_ptr);
592 		break;
593 	case NETDEV_UNREGISTER:
594 	case NETDEV_CHANGENAME:
595 		tipc_disable_bearer(b_ptr->name);
596 		break;
597 	}
598 	rcu_read_unlock();
599 
600 	return NOTIFY_OK;
601 }
602 
603 static struct packet_type tipc_packet_type __read_mostly = {
604 	.type = htons(ETH_P_TIPC),
605 	.func = tipc_l2_rcv_msg,
606 };
607 
608 static struct notifier_block notifier = {
609 	.notifier_call  = tipc_l2_device_event,
610 	.priority	= 0,
611 };
612 
613 int tipc_bearer_setup(void)
614 {
615 	int err;
616 
617 	err = register_netdevice_notifier(&notifier);
618 	if (err)
619 		return err;
620 	dev_add_pack(&tipc_packet_type);
621 	return 0;
622 }
623 
624 void tipc_bearer_cleanup(void)
625 {
626 	unregister_netdevice_notifier(&notifier);
627 	dev_remove_pack(&tipc_packet_type);
628 }
629 
630 void tipc_bearer_stop(void)
631 {
632 	struct tipc_bearer *b_ptr;
633 	u32 i;
634 
635 	for (i = 0; i < MAX_BEARERS; i++) {
636 		b_ptr = bearer_list[i];
637 		if (b_ptr) {
638 			bearer_disable(b_ptr, true);
639 			bearer_list[i] = NULL;
640 		}
641 	}
642 }
643