xref: /openbmc/linux/net/tipc/bearer.c (revision afc98d90)
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 tipc_bearers[MAX_BEARERS];
53 
54 static void bearer_disable(struct tipc_bearer *b_ptr);
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, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
181 		if (b_ptr->active && (!strcmp(b_ptr->name, name)))
182 			return b_ptr;
183 	}
184 	return NULL;
185 }
186 
187 /**
188  * tipc_bearer_get_names - record names of bearers in buffer
189  */
190 struct sk_buff *tipc_bearer_get_names(void)
191 {
192 	struct sk_buff *buf;
193 	struct tipc_bearer *b;
194 	int i, j;
195 
196 	buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME));
197 	if (!buf)
198 		return NULL;
199 
200 	read_lock_bh(&tipc_net_lock);
201 	for (i = 0; media_info_array[i] != NULL; i++) {
202 		for (j = 0; j < MAX_BEARERS; j++) {
203 			b = &tipc_bearers[j];
204 			if (b->active && (b->media == media_info_array[i])) {
205 				tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
206 						    b->name,
207 						    strlen(b->name) + 1);
208 			}
209 		}
210 	}
211 	read_unlock_bh(&tipc_net_lock);
212 	return buf;
213 }
214 
215 void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest)
216 {
217 	tipc_nmap_add(&b_ptr->nodes, dest);
218 	tipc_bcbearer_sort();
219 	tipc_disc_add_dest(b_ptr->link_req);
220 }
221 
222 void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest)
223 {
224 	tipc_nmap_remove(&b_ptr->nodes, dest);
225 	tipc_bcbearer_sort();
226 	tipc_disc_remove_dest(b_ptr->link_req);
227 }
228 
229 /**
230  * tipc_enable_bearer - enable bearer with the given name
231  */
232 int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority)
233 {
234 	struct tipc_bearer *b_ptr;
235 	struct tipc_media *m_ptr;
236 	struct tipc_bearer_names b_names;
237 	char addr_string[16];
238 	u32 bearer_id;
239 	u32 with_this_prio;
240 	u32 i;
241 	int res = -EINVAL;
242 
243 	if (!tipc_own_addr) {
244 		pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
245 			name);
246 		return -ENOPROTOOPT;
247 	}
248 	if (!bearer_name_validate(name, &b_names)) {
249 		pr_warn("Bearer <%s> rejected, illegal name\n", name);
250 		return -EINVAL;
251 	}
252 	if (tipc_addr_domain_valid(disc_domain) &&
253 	    (disc_domain != tipc_own_addr)) {
254 		if (tipc_in_scope(disc_domain, tipc_own_addr)) {
255 			disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK;
256 			res = 0;   /* accept any node in own cluster */
257 		} else if (in_own_cluster_exact(disc_domain))
258 			res = 0;   /* accept specified node in own cluster */
259 	}
260 	if (res) {
261 		pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
262 			name);
263 		return -EINVAL;
264 	}
265 	if ((priority > TIPC_MAX_LINK_PRI) &&
266 	    (priority != TIPC_MEDIA_LINK_PRI)) {
267 		pr_warn("Bearer <%s> rejected, illegal priority\n", name);
268 		return -EINVAL;
269 	}
270 
271 	write_lock_bh(&tipc_net_lock);
272 
273 	m_ptr = tipc_media_find(b_names.media_name);
274 	if (!m_ptr) {
275 		pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
276 			name, b_names.media_name);
277 		goto exit;
278 	}
279 
280 	if (priority == TIPC_MEDIA_LINK_PRI)
281 		priority = m_ptr->priority;
282 
283 restart:
284 	bearer_id = MAX_BEARERS;
285 	with_this_prio = 1;
286 	for (i = MAX_BEARERS; i-- != 0; ) {
287 		if (!tipc_bearers[i].active) {
288 			bearer_id = i;
289 			continue;
290 		}
291 		if (!strcmp(name, tipc_bearers[i].name)) {
292 			pr_warn("Bearer <%s> rejected, already enabled\n",
293 				name);
294 			goto exit;
295 		}
296 		if ((tipc_bearers[i].priority == priority) &&
297 		    (++with_this_prio > 2)) {
298 			if (priority-- == 0) {
299 				pr_warn("Bearer <%s> rejected, duplicate priority\n",
300 					name);
301 				goto exit;
302 			}
303 			pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
304 				name, priority + 1, priority);
305 			goto restart;
306 		}
307 	}
308 	if (bearer_id >= MAX_BEARERS) {
309 		pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
310 			name, MAX_BEARERS);
311 		goto exit;
312 	}
313 
314 	b_ptr = &tipc_bearers[bearer_id];
315 	strcpy(b_ptr->name, name);
316 	b_ptr->media = m_ptr;
317 	res = m_ptr->enable_media(b_ptr);
318 	if (res) {
319 		pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
320 			name, -res);
321 		goto exit;
322 	}
323 
324 	b_ptr->identity = bearer_id;
325 	b_ptr->tolerance = m_ptr->tolerance;
326 	b_ptr->window = m_ptr->window;
327 	b_ptr->net_plane = bearer_id + 'A';
328 	b_ptr->active = 1;
329 	b_ptr->priority = priority;
330 	INIT_LIST_HEAD(&b_ptr->links);
331 	spin_lock_init(&b_ptr->lock);
332 
333 	res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr, disc_domain);
334 	if (res) {
335 		bearer_disable(b_ptr);
336 		pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
337 			name);
338 		goto exit;
339 	}
340 	pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
341 		name,
342 		tipc_addr_string_fill(addr_string, disc_domain), priority);
343 exit:
344 	write_unlock_bh(&tipc_net_lock);
345 	return res;
346 }
347 
348 /**
349  * tipc_reset_bearer - Reset all links established over this bearer
350  */
351 static int tipc_reset_bearer(struct tipc_bearer *b_ptr)
352 {
353 	struct tipc_link *l_ptr;
354 	struct tipc_link *temp_l_ptr;
355 
356 	read_lock_bh(&tipc_net_lock);
357 	pr_info("Resetting bearer <%s>\n", b_ptr->name);
358 	spin_lock_bh(&b_ptr->lock);
359 	list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
360 		struct tipc_node *n_ptr = l_ptr->owner;
361 
362 		spin_lock_bh(&n_ptr->lock);
363 		tipc_link_reset(l_ptr);
364 		spin_unlock_bh(&n_ptr->lock);
365 	}
366 	spin_unlock_bh(&b_ptr->lock);
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)
377 {
378 	struct tipc_link *l_ptr;
379 	struct tipc_link *temp_l_ptr;
380 	struct tipc_link_req *temp_req;
381 
382 	pr_info("Disabling bearer <%s>\n", b_ptr->name);
383 	spin_lock_bh(&b_ptr->lock);
384 	b_ptr->media->disable_media(b_ptr);
385 	list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
386 		tipc_link_delete(l_ptr);
387 	}
388 	temp_req = b_ptr->link_req;
389 	b_ptr->link_req = NULL;
390 	spin_unlock_bh(&b_ptr->lock);
391 
392 	if (temp_req)
393 		tipc_disc_delete(temp_req);
394 
395 	memset(b_ptr, 0, sizeof(struct tipc_bearer));
396 }
397 
398 int tipc_disable_bearer(const char *name)
399 {
400 	struct tipc_bearer *b_ptr;
401 	int res;
402 
403 	write_lock_bh(&tipc_net_lock);
404 	b_ptr = tipc_bearer_find(name);
405 	if (b_ptr == NULL) {
406 		pr_warn("Attempt to disable unknown bearer <%s>\n", name);
407 		res = -EINVAL;
408 	} else {
409 		bearer_disable(b_ptr);
410 		res = 0;
411 	}
412 	write_unlock_bh(&tipc_net_lock);
413 	return res;
414 }
415 
416 
417 /* tipc_l2_media_addr_set - initialize Ethernet media address structure
418  *
419  * Media-dependent "value" field stores MAC address in first 6 bytes
420  * and zeroes out the remaining bytes.
421  */
422 void tipc_l2_media_addr_set(const struct tipc_bearer *b,
423 			    struct tipc_media_addr *a, char *mac)
424 {
425 	int len = b->media->hwaddr_len;
426 
427 	if (unlikely(sizeof(a->value) < len)) {
428 		WARN_ONCE(1, "Media length invalid\n");
429 		return;
430 	}
431 
432 	memcpy(a->value, mac, len);
433 	memset(a->value + len, 0, sizeof(a->value) - len);
434 	a->media_id = b->media->type_id;
435 	a->broadcast = !memcmp(mac, b->bcast_addr.value, len);
436 }
437 
438 int tipc_enable_l2_media(struct tipc_bearer *b)
439 {
440 	struct net_device *dev;
441 	char *driver_name = strchr((const char *)b->name, ':') + 1;
442 
443 	/* Find device with specified name */
444 	dev = dev_get_by_name(&init_net, driver_name);
445 	if (!dev)
446 		return -ENODEV;
447 
448 	/* Associate TIPC bearer with Ethernet bearer */
449 	b->media_ptr = dev;
450 	memset(b->bcast_addr.value, 0, sizeof(b->bcast_addr.value));
451 	memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len);
452 	b->bcast_addr.media_id = b->media->type_id;
453 	b->bcast_addr.broadcast = 1;
454 	b->mtu = dev->mtu;
455 	tipc_l2_media_addr_set(b, &b->addr, (char *)dev->dev_addr);
456 	rcu_assign_pointer(dev->tipc_ptr, b);
457 	return 0;
458 }
459 
460 /* tipc_disable_l2_media - detach TIPC bearer from an Ethernet interface
461  *
462  * Mark Ethernet bearer as inactive so that incoming buffers are thrown away,
463  * then get worker thread to complete bearer cleanup.  (Can't do cleanup
464  * here because cleanup code needs to sleep and caller holds spinlocks.)
465  */
466 void tipc_disable_l2_media(struct tipc_bearer *b)
467 {
468 	struct net_device *dev = (struct net_device *)b->media_ptr;
469 	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
470 	dev_put(dev);
471 }
472 
473 /**
474  * tipc_l2_send_msg - send a TIPC packet out over an Ethernet interface
475  * @buf: the packet to be sent
476  * @b_ptr: the bearer through which the packet is to be sent
477  * @dest: peer destination address
478  */
479 int tipc_l2_send_msg(struct sk_buff *buf, struct tipc_bearer *b,
480 		     struct tipc_media_addr *dest)
481 {
482 	struct sk_buff *clone;
483 	int delta;
484 	struct net_device *dev = (struct net_device *)b->media_ptr;
485 
486 	clone = skb_clone(buf, GFP_ATOMIC);
487 	if (!clone)
488 		return 0;
489 
490 	delta = dev->hard_header_len - skb_headroom(buf);
491 	if ((delta > 0) &&
492 	    pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
493 		kfree_skb(clone);
494 		return 0;
495 	}
496 
497 	skb_reset_network_header(clone);
498 	clone->dev = dev;
499 	clone->protocol = htons(ETH_P_TIPC);
500 	dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
501 			dev->dev_addr, clone->len);
502 	dev_queue_xmit(clone);
503 	return 0;
504 }
505 
506 /* tipc_bearer_send- sends buffer to destination over bearer
507  *
508  * IMPORTANT:
509  * The media send routine must not alter the buffer being passed in
510  * as it may be needed for later retransmission!
511  */
512 void tipc_bearer_send(struct tipc_bearer *b, struct sk_buff *buf,
513 		      struct tipc_media_addr *dest)
514 {
515 	b->media->send_msg(buf, b, dest);
516 }
517 
518 /**
519  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
520  * @buf: the received packet
521  * @dev: the net device that the packet was received on
522  * @pt: the packet_type structure which was used to register this handler
523  * @orig_dev: the original receive net device in case the device is a bond
524  *
525  * Accept only packets explicitly sent to this node, or broadcast packets;
526  * ignores packets sent using interface multicast, and traffic sent to other
527  * nodes (which can happen if interface is running in promiscuous mode).
528  */
529 static int tipc_l2_rcv_msg(struct sk_buff *buf, struct net_device *dev,
530 			   struct packet_type *pt, struct net_device *orig_dev)
531 {
532 	struct tipc_bearer *b_ptr;
533 
534 	if (!net_eq(dev_net(dev), &init_net)) {
535 		kfree_skb(buf);
536 		return NET_RX_DROP;
537 	}
538 
539 	rcu_read_lock();
540 	b_ptr = rcu_dereference(dev->tipc_ptr);
541 	if (likely(b_ptr)) {
542 		if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
543 			buf->next = NULL;
544 			tipc_rcv(buf, b_ptr);
545 			rcu_read_unlock();
546 			return NET_RX_SUCCESS;
547 		}
548 	}
549 	rcu_read_unlock();
550 
551 	kfree_skb(buf);
552 	return NET_RX_DROP;
553 }
554 
555 /**
556  * tipc_l2_device_event - handle device events from network device
557  * @nb: the context of the notification
558  * @evt: the type of event
559  * @ptr: the net device that the event was on
560  *
561  * This function is called by the Ethernet driver in case of link
562  * change event.
563  */
564 static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
565 				void *ptr)
566 {
567 	struct tipc_bearer *b_ptr;
568 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
569 
570 	if (!net_eq(dev_net(dev), &init_net))
571 		return NOTIFY_DONE;
572 
573 	rcu_read_lock();
574 	b_ptr = rcu_dereference(dev->tipc_ptr);
575 	if (!b_ptr) {
576 		rcu_read_unlock();
577 		return NOTIFY_DONE;
578 	}
579 
580 	b_ptr->mtu = dev->mtu;
581 
582 	switch (evt) {
583 	case NETDEV_CHANGE:
584 		if (netif_carrier_ok(dev))
585 			break;
586 	case NETDEV_DOWN:
587 	case NETDEV_CHANGEMTU:
588 	case NETDEV_CHANGEADDR:
589 		tipc_reset_bearer(b_ptr);
590 		break;
591 	case NETDEV_UNREGISTER:
592 	case NETDEV_CHANGENAME:
593 		tipc_disable_bearer(b_ptr->name);
594 		break;
595 	}
596 	rcu_read_unlock();
597 
598 	return NOTIFY_OK;
599 }
600 
601 static struct packet_type tipc_packet_type __read_mostly = {
602 	.type = __constant_htons(ETH_P_TIPC),
603 	.func = tipc_l2_rcv_msg,
604 };
605 
606 static struct notifier_block notifier = {
607 	.notifier_call  = tipc_l2_device_event,
608 	.priority	= 0,
609 };
610 
611 int tipc_bearer_setup(void)
612 {
613 	dev_add_pack(&tipc_packet_type);
614 	return register_netdevice_notifier(&notifier);
615 }
616 
617 void tipc_bearer_cleanup(void)
618 {
619 	unregister_netdevice_notifier(&notifier);
620 	dev_remove_pack(&tipc_packet_type);
621 }
622 
623 void tipc_bearer_stop(void)
624 {
625 	u32 i;
626 
627 	for (i = 0; i < MAX_BEARERS; i++) {
628 		if (tipc_bearers[i].active)
629 			bearer_disable(&tipc_bearers[i]);
630 	}
631 }
632