xref: /linux/net/tipc/bearer.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * net/tipc/bearer.c: TIPC bearer code
3  *
4  * Copyright (c) 1996-2006, Ericsson AB
5  * Copyright (c) 2004-2006, 2010-2011, 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 *media_list[MAX_MEDIA];
45 static u32 media_count;
46 
47 struct tipc_bearer tipc_bearers[MAX_BEARERS];
48 
49 static void bearer_disable(struct tipc_bearer *b_ptr);
50 
51 /**
52  * tipc_media_find - locates specified media object by name
53  */
54 struct tipc_media *tipc_media_find(const char *name)
55 {
56 	u32 i;
57 
58 	for (i = 0; i < media_count; i++) {
59 		if (!strcmp(media_list[i]->name, name))
60 			return media_list[i];
61 	}
62 	return NULL;
63 }
64 
65 /**
66  * media_find_id - locates specified media object by type identifier
67  */
68 static struct tipc_media *media_find_id(u8 type)
69 {
70 	u32 i;
71 
72 	for (i = 0; i < media_count; i++) {
73 		if (media_list[i]->type_id == type)
74 			return media_list[i];
75 	}
76 	return NULL;
77 }
78 
79 /**
80  * tipc_register_media - register a media type
81  *
82  * Bearers for this media type must be activated separately at a later stage.
83  */
84 int tipc_register_media(struct tipc_media *m_ptr)
85 {
86 	int res = -EINVAL;
87 
88 	write_lock_bh(&tipc_net_lock);
89 
90 	if ((strlen(m_ptr->name) + 1) > TIPC_MAX_MEDIA_NAME)
91 		goto exit;
92 	if (m_ptr->priority > TIPC_MAX_LINK_PRI)
93 		goto exit;
94 	if ((m_ptr->tolerance < TIPC_MIN_LINK_TOL) ||
95 	    (m_ptr->tolerance > TIPC_MAX_LINK_TOL))
96 		goto exit;
97 	if (media_count >= MAX_MEDIA)
98 		goto exit;
99 	if (tipc_media_find(m_ptr->name) || media_find_id(m_ptr->type_id))
100 		goto exit;
101 
102 	media_list[media_count] = m_ptr;
103 	media_count++;
104 	res = 0;
105 exit:
106 	write_unlock_bh(&tipc_net_lock);
107 	if (res)
108 		pr_warn("Media <%s> registration error\n", m_ptr->name);
109 	return res;
110 }
111 
112 /**
113  * tipc_media_addr_printf - record media address in print buffer
114  */
115 void tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a)
116 {
117 	char addr_str[MAX_ADDR_STR];
118 	struct tipc_media *m_ptr;
119 	int ret;
120 
121 	m_ptr = media_find_id(a->media_id);
122 
123 	if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str)))
124 		ret = tipc_snprintf(buf, len, "%s(%s)", m_ptr->name, addr_str);
125 	else {
126 		u32 i;
127 
128 		ret = tipc_snprintf(buf, len, "UNKNOWN(%u)", a->media_id);
129 		for (i = 0; i < sizeof(a->value); i++)
130 			ret += tipc_snprintf(buf - ret, len + ret,
131 					    "-%02x", a->value[i]);
132 	}
133 }
134 
135 /**
136  * tipc_media_get_names - record names of registered media in buffer
137  */
138 struct sk_buff *tipc_media_get_names(void)
139 {
140 	struct sk_buff *buf;
141 	int i;
142 
143 	buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME));
144 	if (!buf)
145 		return NULL;
146 
147 	read_lock_bh(&tipc_net_lock);
148 	for (i = 0; i < media_count; i++) {
149 		tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME,
150 				    media_list[i]->name,
151 				    strlen(media_list[i]->name) + 1);
152 	}
153 	read_unlock_bh(&tipc_net_lock);
154 	return buf;
155 }
156 
157 /**
158  * bearer_name_validate - validate & (optionally) deconstruct bearer name
159  * @name: ptr to bearer name string
160  * @name_parts: ptr to area for bearer name components (or NULL if not needed)
161  *
162  * Returns 1 if bearer name is valid, otherwise 0.
163  */
164 static int bearer_name_validate(const char *name,
165 				struct tipc_bearer_names *name_parts)
166 {
167 	char name_copy[TIPC_MAX_BEARER_NAME];
168 	char *media_name;
169 	char *if_name;
170 	u32 media_len;
171 	u32 if_len;
172 
173 	/* copy bearer name & ensure length is OK */
174 	name_copy[TIPC_MAX_BEARER_NAME - 1] = 0;
175 	/* need above in case non-Posix strncpy() doesn't pad with nulls */
176 	strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
177 	if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0)
178 		return 0;
179 
180 	/* ensure all component parts of bearer name are present */
181 	media_name = name_copy;
182 	if_name = strchr(media_name, ':');
183 	if (if_name == NULL)
184 		return 0;
185 	*(if_name++) = 0;
186 	media_len = if_name - media_name;
187 	if_len = strlen(if_name) + 1;
188 
189 	/* validate component parts of bearer name */
190 	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
191 	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
192 		return 0;
193 
194 	/* return bearer name components, if necessary */
195 	if (name_parts) {
196 		strcpy(name_parts->media_name, media_name);
197 		strcpy(name_parts->if_name, if_name);
198 	}
199 	return 1;
200 }
201 
202 /**
203  * tipc_bearer_find - locates bearer object with matching bearer name
204  */
205 struct tipc_bearer *tipc_bearer_find(const char *name)
206 {
207 	struct tipc_bearer *b_ptr;
208 	u32 i;
209 
210 	for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
211 		if (b_ptr->active && (!strcmp(b_ptr->name, name)))
212 			return b_ptr;
213 	}
214 	return NULL;
215 }
216 
217 /**
218  * tipc_bearer_find_interface - locates bearer object with matching interface name
219  */
220 struct tipc_bearer *tipc_bearer_find_interface(const char *if_name)
221 {
222 	struct tipc_bearer *b_ptr;
223 	char *b_if_name;
224 	u32 i;
225 
226 	for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
227 		if (!b_ptr->active)
228 			continue;
229 		b_if_name = strchr(b_ptr->name, ':') + 1;
230 		if (!strcmp(b_if_name, if_name))
231 			return b_ptr;
232 	}
233 	return NULL;
234 }
235 
236 /**
237  * tipc_bearer_get_names - record names of bearers in buffer
238  */
239 struct sk_buff *tipc_bearer_get_names(void)
240 {
241 	struct sk_buff *buf;
242 	struct tipc_bearer *b_ptr;
243 	int i, j;
244 
245 	buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME));
246 	if (!buf)
247 		return NULL;
248 
249 	read_lock_bh(&tipc_net_lock);
250 	for (i = 0; i < media_count; i++) {
251 		for (j = 0; j < MAX_BEARERS; j++) {
252 			b_ptr = &tipc_bearers[j];
253 			if (b_ptr->active && (b_ptr->media == media_list[i])) {
254 				tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
255 						    b_ptr->name,
256 						    strlen(b_ptr->name) + 1);
257 			}
258 		}
259 	}
260 	read_unlock_bh(&tipc_net_lock);
261 	return buf;
262 }
263 
264 void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest)
265 {
266 	tipc_nmap_add(&b_ptr->nodes, dest);
267 	tipc_bcbearer_sort();
268 	tipc_disc_add_dest(b_ptr->link_req);
269 }
270 
271 void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest)
272 {
273 	tipc_nmap_remove(&b_ptr->nodes, dest);
274 	tipc_bcbearer_sort();
275 	tipc_disc_remove_dest(b_ptr->link_req);
276 }
277 
278 /*
279  * Interrupt enabling new requests after bearer blocking:
280  * See bearer_send().
281  */
282 void tipc_continue(struct tipc_bearer *b)
283 {
284 	spin_lock_bh(&b->lock);
285 	b->blocked = 0;
286 	spin_unlock_bh(&b->lock);
287 }
288 
289 /*
290  * tipc_bearer_blocked - determines if bearer is currently blocked
291  */
292 int tipc_bearer_blocked(struct tipc_bearer *b)
293 {
294 	int res;
295 
296 	spin_lock_bh(&b->lock);
297 	res = b->blocked;
298 	spin_unlock_bh(&b->lock);
299 
300 	return res;
301 }
302 
303 /**
304  * tipc_enable_bearer - enable bearer with the given name
305  */
306 int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority)
307 {
308 	struct tipc_bearer *b_ptr;
309 	struct tipc_media *m_ptr;
310 	struct tipc_bearer_names b_names;
311 	char addr_string[16];
312 	u32 bearer_id;
313 	u32 with_this_prio;
314 	u32 i;
315 	int res = -EINVAL;
316 
317 	if (!tipc_own_addr) {
318 		pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
319 			name);
320 		return -ENOPROTOOPT;
321 	}
322 	if (!bearer_name_validate(name, &b_names)) {
323 		pr_warn("Bearer <%s> rejected, illegal name\n", name);
324 		return -EINVAL;
325 	}
326 	if (tipc_addr_domain_valid(disc_domain) &&
327 	    (disc_domain != tipc_own_addr)) {
328 		if (tipc_in_scope(disc_domain, tipc_own_addr)) {
329 			disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK;
330 			res = 0;   /* accept any node in own cluster */
331 		} else if (in_own_cluster_exact(disc_domain))
332 			res = 0;   /* accept specified node in own cluster */
333 	}
334 	if (res) {
335 		pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
336 			name);
337 		return -EINVAL;
338 	}
339 	if ((priority > TIPC_MAX_LINK_PRI) &&
340 	    (priority != TIPC_MEDIA_LINK_PRI)) {
341 		pr_warn("Bearer <%s> rejected, illegal priority\n", name);
342 		return -EINVAL;
343 	}
344 
345 	write_lock_bh(&tipc_net_lock);
346 
347 	m_ptr = tipc_media_find(b_names.media_name);
348 	if (!m_ptr) {
349 		pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
350 			name, b_names.media_name);
351 		goto exit;
352 	}
353 
354 	if (priority == TIPC_MEDIA_LINK_PRI)
355 		priority = m_ptr->priority;
356 
357 restart:
358 	bearer_id = MAX_BEARERS;
359 	with_this_prio = 1;
360 	for (i = MAX_BEARERS; i-- != 0; ) {
361 		if (!tipc_bearers[i].active) {
362 			bearer_id = i;
363 			continue;
364 		}
365 		if (!strcmp(name, tipc_bearers[i].name)) {
366 			pr_warn("Bearer <%s> rejected, already enabled\n",
367 				name);
368 			goto exit;
369 		}
370 		if ((tipc_bearers[i].priority == priority) &&
371 		    (++with_this_prio > 2)) {
372 			if (priority-- == 0) {
373 				pr_warn("Bearer <%s> rejected, duplicate priority\n",
374 					name);
375 				goto exit;
376 			}
377 			pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
378 				name, priority + 1, priority);
379 			goto restart;
380 		}
381 	}
382 	if (bearer_id >= MAX_BEARERS) {
383 		pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
384 			name, MAX_BEARERS);
385 		goto exit;
386 	}
387 
388 	b_ptr = &tipc_bearers[bearer_id];
389 	strcpy(b_ptr->name, name);
390 	res = m_ptr->enable_media(b_ptr);
391 	if (res) {
392 		pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
393 			name, -res);
394 		goto exit;
395 	}
396 
397 	b_ptr->identity = bearer_id;
398 	b_ptr->media = m_ptr;
399 	b_ptr->tolerance = m_ptr->tolerance;
400 	b_ptr->window = m_ptr->window;
401 	b_ptr->net_plane = bearer_id + 'A';
402 	b_ptr->active = 1;
403 	b_ptr->priority = priority;
404 	INIT_LIST_HEAD(&b_ptr->links);
405 	spin_lock_init(&b_ptr->lock);
406 
407 	res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr, disc_domain);
408 	if (res) {
409 		bearer_disable(b_ptr);
410 		pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
411 			name);
412 		goto exit;
413 	}
414 	pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
415 		name,
416 		tipc_addr_string_fill(addr_string, disc_domain), priority);
417 exit:
418 	write_unlock_bh(&tipc_net_lock);
419 	return res;
420 }
421 
422 /**
423  * tipc_block_bearer - Block the bearer, and reset all its links
424  */
425 int tipc_block_bearer(struct tipc_bearer *b_ptr)
426 {
427 	struct tipc_link *l_ptr;
428 	struct tipc_link *temp_l_ptr;
429 
430 	read_lock_bh(&tipc_net_lock);
431 	pr_info("Blocking bearer <%s>\n", b_ptr->name);
432 	spin_lock_bh(&b_ptr->lock);
433 	b_ptr->blocked = 1;
434 	list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
435 		struct tipc_node *n_ptr = l_ptr->owner;
436 
437 		spin_lock_bh(&n_ptr->lock);
438 		tipc_link_reset(l_ptr);
439 		spin_unlock_bh(&n_ptr->lock);
440 	}
441 	spin_unlock_bh(&b_ptr->lock);
442 	read_unlock_bh(&tipc_net_lock);
443 	return 0;
444 }
445 
446 /**
447  * bearer_disable
448  *
449  * Note: This routine assumes caller holds tipc_net_lock.
450  */
451 static void bearer_disable(struct tipc_bearer *b_ptr)
452 {
453 	struct tipc_link *l_ptr;
454 	struct tipc_link *temp_l_ptr;
455 	struct tipc_link_req *temp_req;
456 
457 	pr_info("Disabling bearer <%s>\n", b_ptr->name);
458 	spin_lock_bh(&b_ptr->lock);
459 	b_ptr->blocked = 1;
460 	b_ptr->media->disable_media(b_ptr);
461 	list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
462 		tipc_link_delete(l_ptr);
463 	}
464 	temp_req = b_ptr->link_req;
465 	b_ptr->link_req = NULL;
466 	spin_unlock_bh(&b_ptr->lock);
467 
468 	if (temp_req)
469 		tipc_disc_delete(temp_req);
470 
471 	memset(b_ptr, 0, sizeof(struct tipc_bearer));
472 }
473 
474 int tipc_disable_bearer(const char *name)
475 {
476 	struct tipc_bearer *b_ptr;
477 	int res;
478 
479 	write_lock_bh(&tipc_net_lock);
480 	b_ptr = tipc_bearer_find(name);
481 	if (b_ptr == NULL) {
482 		pr_warn("Attempt to disable unknown bearer <%s>\n", name);
483 		res = -EINVAL;
484 	} else {
485 		bearer_disable(b_ptr);
486 		res = 0;
487 	}
488 	write_unlock_bh(&tipc_net_lock);
489 	return res;
490 }
491 
492 
493 
494 void tipc_bearer_stop(void)
495 {
496 	u32 i;
497 
498 	for (i = 0; i < MAX_BEARERS; i++) {
499 		if (tipc_bearers[i].active)
500 			bearer_disable(&tipc_bearers[i]);
501 	}
502 	media_count = 0;
503 }
504