bearer.c 17.1 KB
Newer Older
Per Liden's avatar
Per Liden committed
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
Per Liden's avatar
Per Liden committed
6
7
 * All rights reserved.
 *
Per Liden's avatar
Per Liden committed
8
 * Redistribution and use in source and binary forms, with or without
Per Liden's avatar
Per Liden committed
9
10
 * modification, are permitted provided that the following conditions are met:
 *
Per Liden's avatar
Per Liden committed
11
12
13
14
15
16
17
18
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
Per Liden's avatar
Per Liden committed
19
 *
Per Liden's avatar
Per Liden committed
20
21
22
23
24
25
26
27
28
29
30
31
32
33
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
Per Liden's avatar
Per Liden committed
34
35
36
37
38
39
40
41
42
43
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "core.h"
#include "config.h"
#include "bearer.h"
#include "discover.h"

#define MAX_ADDR_STR 32

44
static struct media media_list[MAX_MEDIA];
45
static u32 media_count;
Per Liden's avatar
Per Liden committed
46

47
struct tipc_bearer tipc_bearers[MAX_BEARERS];
Per Liden's avatar
Per Liden committed
48

49
50
static void bearer_disable(struct tipc_bearer *b_ptr);

Per Liden's avatar
Per Liden committed
51
52
/**
 * media_name_valid - validate media name
53
 *
Per Liden's avatar
Per Liden committed
54
55
56
57
58
59
60
61
62
63
 * Returns 1 if media name is valid, otherwise 0.
 */

static int media_name_valid(const char *name)
{
	u32 len;

	len = strlen(name);
	if ((len + 1) > TIPC_MAX_MEDIA_NAME)
		return 0;
Eric Dumazet's avatar
Eric Dumazet committed
64
	return strspn(name, tipc_alphabet) == len;
Per Liden's avatar
Per Liden committed
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
}

/**
 * media_find - locates specified media object by name
 */

static struct media *media_find(const char *name)
{
	struct media *m_ptr;
	u32 i;

	for (i = 0, m_ptr = media_list; i < media_count; i++, m_ptr++) {
		if (!strcmp(m_ptr->name, name))
			return m_ptr;
	}
80
	return NULL;
Per Liden's avatar
Per Liden committed
81
82
83
84
}

/**
 * tipc_register_media - register a media type
85
 *
Per Liden's avatar
Per Liden committed
86
87
88
89
 * Bearers for this media type must be activated separately at a later stage.
 */

int  tipc_register_media(u32 media_type,
90
91
92
93
			 char *name,
			 int (*enable)(struct tipc_bearer *),
			 void (*disable)(struct tipc_bearer *),
			 int (*send_msg)(struct sk_buff *,
Per Liden's avatar
Per Liden committed
94
					 struct tipc_bearer *,
95
					 struct tipc_media_addr *),
Per Liden's avatar
Per Liden committed
96
97
98
99
100
101
102
103
104
105
106
107
			 char *(*addr2str)(struct tipc_media_addr *a,
					   char *str_buf, int str_size),
			 struct tipc_media_addr *bcast_addr,
			 const u32 bearer_priority,
			 const u32 link_tolerance,  /* [ms] */
			 const u32 send_window_limit)
{
	struct media *m_ptr;
	u32 media_id;
	u32 i;
	int res = -EINVAL;

108
	write_lock_bh(&tipc_net_lock);
Per Liden's avatar
Per Liden committed
109

110
111
112
113
	if (tipc_mode != TIPC_NET_MODE) {
		warn("Media <%s> rejected, not in networked mode yet\n", name);
		goto exit;
	}
Per Liden's avatar
Per Liden committed
114
	if (!media_name_valid(name)) {
115
		warn("Media <%s> rejected, illegal name\n", name);
Per Liden's avatar
Per Liden committed
116
117
118
		goto exit;
	}
	if (!bcast_addr) {
119
		warn("Media <%s> rejected, no broadcast address\n", name);
Per Liden's avatar
Per Liden committed
120
121
		goto exit;
	}
122
	if ((bearer_priority < TIPC_MIN_LINK_PRI) ||
123
	    (bearer_priority > TIPC_MAX_LINK_PRI)) {
124
		warn("Media <%s> rejected, illegal priority (%u)\n", name,
125
		     bearer_priority);
Per Liden's avatar
Per Liden committed
126
127
		goto exit;
	}
128
	if ((link_tolerance < TIPC_MIN_LINK_TOL) ||
Per Liden's avatar
Per Liden committed
129
	    (link_tolerance > TIPC_MAX_LINK_TOL)) {
130
131
		warn("Media <%s> rejected, illegal tolerance (%u)\n", name,
		     link_tolerance);
Per Liden's avatar
Per Liden committed
132
133
134
135
136
		goto exit;
	}

	media_id = media_count++;
	if (media_id >= MAX_MEDIA) {
137
138
		warn("Media <%s> rejected, media limit reached (%u)\n", name,
		     MAX_MEDIA);
Per Liden's avatar
Per Liden committed
139
140
141
142
143
		media_count--;
		goto exit;
	}
	for (i = 0; i < media_id; i++) {
		if (media_list[i].type_id == media_type) {
144
			warn("Media <%s> rejected, duplicate type (%u)\n", name,
Per Liden's avatar
Per Liden committed
145
146
147
148
149
			     media_type);
			media_count--;
			goto exit;
		}
		if (!strcmp(name, media_list[i].name)) {
150
			warn("Media <%s> rejected, duplicate name\n", name);
Per Liden's avatar
Per Liden committed
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
			media_count--;
			goto exit;
		}
	}

	m_ptr = &media_list[media_id];
	m_ptr->type_id = media_type;
	m_ptr->send_msg = send_msg;
	m_ptr->enable_bearer = enable;
	m_ptr->disable_bearer = disable;
	m_ptr->addr2str = addr2str;
	memcpy(&m_ptr->bcast_addr, bcast_addr, sizeof(*bcast_addr));
	strcpy(m_ptr->name, name);
	m_ptr->priority = bearer_priority;
	m_ptr->tolerance = link_tolerance;
	m_ptr->window = send_window_limit;
	res = 0;
exit:
169
	write_unlock_bh(&tipc_net_lock);
Per Liden's avatar
Per Liden committed
170
171
172
173
	return res;
}

/**
174
 * tipc_media_addr_printf - record media address in print buffer
Per Liden's avatar
Per Liden committed
175
176
 */

177
void tipc_media_addr_printf(struct print_buf *pb, struct tipc_media_addr *a)
Per Liden's avatar
Per Liden committed
178
179
180
181
182
183
184
185
186
187
188
189
190
191
{
	struct media *m_ptr;
	u32 media_type;
	u32 i;

	media_type = ntohl(a->type);
	for (i = 0, m_ptr = media_list; i < media_count; i++, m_ptr++) {
		if (m_ptr->type_id == media_type)
			break;
	}

	if ((i < media_count) && (m_ptr->addr2str != NULL)) {
		char addr_str[MAX_ADDR_STR];

192
		tipc_printf(pb, "%s(%s)", m_ptr->name,
Per Liden's avatar
Per Liden committed
193
194
195
196
			    m_ptr->addr2str(a, addr_str, sizeof(addr_str)));
	} else {
		unchar *addr = (unchar *)&a->dev_addr;

197
		tipc_printf(pb, "UNKNOWN(%u)", media_type);
198
		for (i = 0; i < (sizeof(*a) - sizeof(a->type)); i++)
199
			tipc_printf(pb, "-%02x", addr[i]);
Per Liden's avatar
Per Liden committed
200
201
202
203
	}
}

/**
204
 * tipc_media_get_names - record names of registered media in buffer
Per Liden's avatar
Per Liden committed
205
206
 */

207
struct sk_buff *tipc_media_get_names(void)
Per Liden's avatar
Per Liden committed
208
209
210
211
212
{
	struct sk_buff *buf;
	struct media *m_ptr;
	int i;

213
	buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME));
Per Liden's avatar
Per Liden committed
214
215
216
	if (!buf)
		return NULL;

217
	read_lock_bh(&tipc_net_lock);
Per Liden's avatar
Per Liden committed
218
	for (i = 0, m_ptr = media_list; i < media_count; i++, m_ptr++) {
219
		tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME, m_ptr->name,
220
				    strlen(m_ptr->name) + 1);
Per Liden's avatar
Per Liden committed
221
	}
222
	read_unlock_bh(&tipc_net_lock);
Per Liden's avatar
Per Liden committed
223
224
225
226
227
228
229
	return buf;
}

/**
 * bearer_name_validate - validate & (optionally) deconstruct bearer name
 * @name - ptr to bearer name string
 * @name_parts - ptr to area for bearer name components (or NULL if not needed)
230
 *
Per Liden's avatar
Per Liden committed
231
232
233
 * Returns 1 if bearer name is valid, otherwise 0.
 */

234
static int bearer_name_validate(const char *name,
Per Liden's avatar
Per Liden committed
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
				struct bearer_name *name_parts)
{
	char name_copy[TIPC_MAX_BEARER_NAME];
	char *media_name;
	char *if_name;
	u32 media_len;
	u32 if_len;

	/* copy bearer name & ensure length is OK */

	name_copy[TIPC_MAX_BEARER_NAME - 1] = 0;
	/* need above in case non-Posix strncpy() doesn't pad with nulls */
	strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
	if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0)
		return 0;

	/* ensure all component parts of bearer name are present */

	media_name = name_copy;
254
255
	if_name = strchr(media_name, ':');
	if (if_name == NULL)
Per Liden's avatar
Per Liden committed
256
257
258
259
260
261
262
		return 0;
	*(if_name++) = 0;
	media_len = if_name - media_name;
	if_len = strlen(if_name) + 1;

	/* validate component parts of bearer name */

263
264
	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME) ||
Per Liden's avatar
Per Liden committed
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
	    (strspn(media_name, tipc_alphabet) != (media_len - 1)) ||
	    (strspn(if_name, tipc_alphabet) != (if_len - 1)))
		return 0;

	/* return bearer name components, if necessary */

	if (name_parts) {
		strcpy(name_parts->media_name, media_name);
		strcpy(name_parts->if_name, if_name);
	}
	return 1;
}

/**
 * bearer_find - locates bearer object with matching bearer name
 */

282
static struct tipc_bearer *bearer_find(const char *name)
Per Liden's avatar
Per Liden committed
283
{
284
	struct tipc_bearer *b_ptr;
Per Liden's avatar
Per Liden committed
285
286
	u32 i;

287
	for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
288
		if (b_ptr->active && (!strcmp(b_ptr->name, name)))
Per Liden's avatar
Per Liden committed
289
290
			return b_ptr;
	}
291
	return NULL;
Per Liden's avatar
Per Liden committed
292
293
294
}

/**
295
 * tipc_bearer_find_interface - locates bearer object with matching interface name
Per Liden's avatar
Per Liden committed
296
297
 */

298
struct tipc_bearer *tipc_bearer_find_interface(const char *if_name)
Per Liden's avatar
Per Liden committed
299
{
300
	struct tipc_bearer *b_ptr;
Per Liden's avatar
Per Liden committed
301
302
303
	char *b_if_name;
	u32 i;

304
	for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
Per Liden's avatar
Per Liden committed
305
306
		if (!b_ptr->active)
			continue;
307
		b_if_name = strchr(b_ptr->name, ':') + 1;
Per Liden's avatar
Per Liden committed
308
309
310
		if (!strcmp(b_if_name, if_name))
			return b_ptr;
	}
311
	return NULL;
Per Liden's avatar
Per Liden committed
312
313
314
}

/**
315
 * tipc_bearer_get_names - record names of bearers in buffer
Per Liden's avatar
Per Liden committed
316
317
 */

318
struct sk_buff *tipc_bearer_get_names(void)
Per Liden's avatar
Per Liden committed
319
320
321
{
	struct sk_buff *buf;
	struct media *m_ptr;
322
	struct tipc_bearer *b_ptr;
Per Liden's avatar
Per Liden committed
323
324
	int i, j;

325
	buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME));
Per Liden's avatar
Per Liden committed
326
327
328
	if (!buf)
		return NULL;

329
	read_lock_bh(&tipc_net_lock);
Per Liden's avatar
Per Liden committed
330
331
	for (i = 0, m_ptr = media_list; i < media_count; i++, m_ptr++) {
		for (j = 0; j < MAX_BEARERS; j++) {
332
			b_ptr = &tipc_bearers[j];
Per Liden's avatar
Per Liden committed
333
			if (b_ptr->active && (b_ptr->media == m_ptr)) {
334
				tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
335
336
						    b_ptr->name,
						    strlen(b_ptr->name) + 1);
Per Liden's avatar
Per Liden committed
337
338
339
			}
		}
	}
340
	read_unlock_bh(&tipc_net_lock);
Per Liden's avatar
Per Liden committed
341
342
343
	return buf;
}

344
void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest)
Per Liden's avatar
Per Liden committed
345
{
346
347
	tipc_nmap_add(&b_ptr->nodes, dest);
	tipc_bcbearer_sort();
348
	tipc_disc_add_dest(b_ptr->link_req);
Per Liden's avatar
Per Liden committed
349
350
}

351
void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest)
Per Liden's avatar
Per Liden committed
352
{
353
354
	tipc_nmap_remove(&b_ptr->nodes, dest);
	tipc_bcbearer_sort();
355
	tipc_disc_remove_dest(b_ptr->link_req);
Per Liden's avatar
Per Liden committed
356
357
358
359
360
361
}

/*
 * bearer_push(): Resolve bearer congestion. Force the waiting
 * links to push out their unsent packets, one packet per link
 * per iteration, until all packets are gone or congestion reoccurs.
362
 * 'tipc_net_lock' is read_locked when this function is called
Per Liden's avatar
Per Liden committed
363
364
365
 * bearer.lock must be taken before calling
 * Returns binary true(1) ore false(0)
 */
366
static int bearer_push(struct tipc_bearer *b_ptr)
Per Liden's avatar
Per Liden committed
367
{
368
	u32 res = 0;
Per Liden's avatar
Per Liden committed
369
370
	struct link *ln, *tln;

371
	if (b_ptr->blocked)
Per Liden's avatar
Per Liden committed
372
373
374
375
		return 0;

	while (!list_empty(&b_ptr->cong_links) && (res != PUSH_FAILED)) {
		list_for_each_entry_safe(ln, tln, &b_ptr->cong_links, link_list) {
376
			res = tipc_link_push_packet(ln);
Per Liden's avatar
Per Liden committed
377
378
379
380
381
382
383
384
385
			if (res == PUSH_FAILED)
				break;
			if (res == PUSH_FINISHED)
				list_move_tail(&ln->link_list, &b_ptr->links);
		}
	}
	return list_empty(&b_ptr->cong_links);
}

386
void tipc_bearer_lock_push(struct tipc_bearer *b_ptr)
Per Liden's avatar
Per Liden committed
387
388
389
{
	int res;

390
	spin_lock_bh(&b_ptr->lock);
Per Liden's avatar
Per Liden committed
391
	res = bearer_push(b_ptr);
392
	spin_unlock_bh(&b_ptr->lock);
Per Liden's avatar
Per Liden committed
393
	if (res)
394
		tipc_bcbearer_push();
Per Liden's avatar
Per Liden committed
395
396
397
398
}


/*
399
400
 * Interrupt enabling new requests after bearer congestion or blocking:
 * See bearer_send().
Per Liden's avatar
Per Liden committed
401
 */
402
void tipc_continue(struct tipc_bearer *b_ptr)
Per Liden's avatar
Per Liden committed
403
{
404
	spin_lock_bh(&b_ptr->lock);
Per Liden's avatar
Per Liden committed
405
	if (!list_empty(&b_ptr->cong_links))
406
		tipc_k_signal((Handler)tipc_bearer_lock_push, (unsigned long)b_ptr);
407
408
	b_ptr->blocked = 0;
	spin_unlock_bh(&b_ptr->lock);
Per Liden's avatar
Per Liden committed
409
410
411
}

/*
412
413
414
 * Schedule link for sending of messages after the bearer
 * has been deblocked by 'continue()'. This method is called
 * when somebody tries to send a message via this link while
415
 * the bearer is congested. 'tipc_net_lock' is in read_lock here
Per Liden's avatar
Per Liden committed
416
417
418
 * bearer.lock is busy
 */

419
static void tipc_bearer_schedule_unlocked(struct tipc_bearer *b_ptr, struct link *l_ptr)
Per Liden's avatar
Per Liden committed
420
421
422
423
424
{
	list_move_tail(&l_ptr->link_list, &b_ptr->cong_links);
}

/*
425
426
427
 * Schedule link for sending of messages after the bearer
 * has been deblocked by 'continue()'. This method is called
 * when somebody tries to send a message via this link while
428
 * the bearer is congested. 'tipc_net_lock' is in read_lock here,
Per Liden's avatar
Per Liden committed
429
430
431
 * bearer.lock is free
 */

432
void tipc_bearer_schedule(struct tipc_bearer *b_ptr, struct link *l_ptr)
Per Liden's avatar
Per Liden committed
433
{
434
	spin_lock_bh(&b_ptr->lock);
435
	tipc_bearer_schedule_unlocked(b_ptr, l_ptr);
436
	spin_unlock_bh(&b_ptr->lock);
Per Liden's avatar
Per Liden committed
437
438
439
440
}


/*
441
 * tipc_bearer_resolve_congestion(): Check if there is bearer congestion,
Per Liden's avatar
Per Liden committed
442
 * and if there is, try to resolve it before returning.
443
 * 'tipc_net_lock' is read_locked when this function is called
Per Liden's avatar
Per Liden committed
444
 */
445
int tipc_bearer_resolve_congestion(struct tipc_bearer *b_ptr, struct link *l_ptr)
Per Liden's avatar
Per Liden committed
446
447
448
449
450
{
	int res = 1;

	if (list_empty(&b_ptr->cong_links))
		return 1;
451
	spin_lock_bh(&b_ptr->lock);
Per Liden's avatar
Per Liden committed
452
	if (!bearer_push(b_ptr)) {
453
		tipc_bearer_schedule_unlocked(b_ptr, l_ptr);
Per Liden's avatar
Per Liden committed
454
455
		res = 0;
	}
456
	spin_unlock_bh(&b_ptr->lock);
Per Liden's avatar
Per Liden committed
457
458
459
	return res;
}

460
461
462
463
/**
 * tipc_bearer_congested - determines if bearer is currently congested
 */

464
int tipc_bearer_congested(struct tipc_bearer *b_ptr, struct link *l_ptr)
465
{
466
	if (unlikely(b_ptr->blocked))
467
468
469
470
471
		return 1;
	if (likely(list_empty(&b_ptr->cong_links)))
		return 0;
	return !tipc_bearer_resolve_congestion(b_ptr, l_ptr);
}
Per Liden's avatar
Per Liden committed
472
473
474

/**
 * tipc_enable_bearer - enable bearer with the given name
475
 */
Per Liden's avatar
Per Liden committed
476

477
int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority)
Per Liden's avatar
Per Liden committed
478
{
479
	struct tipc_bearer *b_ptr;
Per Liden's avatar
Per Liden committed
480
481
482
483
484
485
486
487
	struct media *m_ptr;
	struct bearer_name b_name;
	char addr_string[16];
	u32 bearer_id;
	u32 with_this_prio;
	u32 i;
	int res = -EINVAL;

488
489
490
	if (tipc_mode != TIPC_NET_MODE) {
		warn("Bearer <%s> rejected, not supported in standalone mode\n",
		     name);
Per Liden's avatar
Per Liden committed
491
		return -ENOPROTOOPT;
492
493
494
	}
	if (!bearer_name_validate(name, &b_name)) {
		warn("Bearer <%s> rejected, illegal name\n", name);
495
		return -EINVAL;
496
	}
497
498
499
500
501
502
503
504
505
	if (tipc_addr_domain_valid(disc_domain) &&
	    (disc_domain != tipc_own_addr)) {
		if (tipc_in_scope(disc_domain, tipc_own_addr)) {
			disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK;
			res = 0;   /* accept any node in own cluster */
		} else if (in_own_cluster(disc_domain))
			res = 0;   /* accept specified node in own cluster */
	}
	if (res) {
506
		warn("Bearer <%s> rejected, illegal discovery domain\n", name);
507
508
		return -EINVAL;
	}
509
510
	if ((priority < TIPC_MIN_LINK_PRI ||
	     priority > TIPC_MAX_LINK_PRI) &&
511
512
	    (priority != TIPC_MEDIA_LINK_PRI)) {
		warn("Bearer <%s> rejected, illegal priority\n", name);
Per Liden's avatar
Per Liden committed
513
		return -EINVAL;
514
	}
Per Liden's avatar
Per Liden committed
515

516
	write_lock_bh(&tipc_net_lock);
Per Liden's avatar
Per Liden committed
517
518
519

	m_ptr = media_find(b_name.media_name);
	if (!m_ptr) {
520
521
		warn("Bearer <%s> rejected, media <%s> not registered\n", name,
		     b_name.media_name);
522
		goto exit;
Per Liden's avatar
Per Liden committed
523
	}
524
525

	if (priority == TIPC_MEDIA_LINK_PRI)
Per Liden's avatar
Per Liden committed
526
527
528
529
530
531
		priority = m_ptr->priority;

restart:
	bearer_id = MAX_BEARERS;
	with_this_prio = 1;
	for (i = MAX_BEARERS; i-- != 0; ) {
532
		if (!tipc_bearers[i].active) {
Per Liden's avatar
Per Liden committed
533
534
535
			bearer_id = i;
			continue;
		}
536
		if (!strcmp(name, tipc_bearers[i].name)) {
537
			warn("Bearer <%s> rejected, already enabled\n", name);
538
			goto exit;
Per Liden's avatar
Per Liden committed
539
		}
540
		if ((tipc_bearers[i].priority == priority) &&
Per Liden's avatar
Per Liden committed
541
542
		    (++with_this_prio > 2)) {
			if (priority-- == 0) {
543
544
				warn("Bearer <%s> rejected, duplicate priority\n",
				     name);
545
				goto exit;
Per Liden's avatar
Per Liden committed
546
			}
547
			warn("Bearer <%s> priority adjustment required %u->%u\n",
Per Liden's avatar
Per Liden committed
548
549
550
551
552
			     name, priority + 1, priority);
			goto restart;
		}
	}
	if (bearer_id >= MAX_BEARERS) {
553
		warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
554
		     name, MAX_BEARERS);
555
		goto exit;
Per Liden's avatar
Per Liden committed
556
557
	}

558
	b_ptr = &tipc_bearers[bearer_id];
559
560
	strcpy(b_ptr->name, name);
	res = m_ptr->enable_bearer(b_ptr);
Per Liden's avatar
Per Liden committed
561
	if (res) {
562
		warn("Bearer <%s> rejected, enable failure (%d)\n", name, -res);
563
		goto exit;
Per Liden's avatar
Per Liden committed
564
565
566
567
568
569
570
571
572
	}

	b_ptr->identity = bearer_id;
	b_ptr->media = m_ptr;
	b_ptr->net_plane = bearer_id + 'A';
	b_ptr->active = 1;
	b_ptr->priority = priority;
	INIT_LIST_HEAD(&b_ptr->cong_links);
	INIT_LIST_HEAD(&b_ptr->links);
573
	spin_lock_init(&b_ptr->lock);
574
575
576
577
578
579
580
581

	res = tipc_disc_create(b_ptr, &m_ptr->bcast_addr, disc_domain);
	if (res) {
		bearer_disable(b_ptr);
		warn("Bearer <%s> rejected, discovery object creation failed\n",
		     name);
		goto exit;
	}
582
	info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
583
	     name, tipc_addr_string_fill(addr_string, disc_domain), priority);
584
exit:
585
	write_unlock_bh(&tipc_net_lock);
Per Liden's avatar
Per Liden committed
586
587
588
589
590
591
592
593
594
595
	return res;
}

/**
 * tipc_block_bearer(): Block the bearer with the given name,
 *                      and reset all its links
 */

int tipc_block_bearer(const char *name)
{
596
	struct tipc_bearer *b_ptr = NULL;
Per Liden's avatar
Per Liden committed
597
598
599
	struct link *l_ptr;
	struct link *temp_l_ptr;

600
	read_lock_bh(&tipc_net_lock);
Per Liden's avatar
Per Liden committed
601
602
603
	b_ptr = bearer_find(name);
	if (!b_ptr) {
		warn("Attempt to block unknown bearer <%s>\n", name);
604
		read_unlock_bh(&tipc_net_lock);
Per Liden's avatar
Per Liden committed
605
606
607
		return -EINVAL;
	}

608
	info("Blocking bearer <%s>\n", name);
609
610
	spin_lock_bh(&b_ptr->lock);
	b_ptr->blocked = 1;
Per Liden's avatar
Per Liden committed
611
	list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
612
		struct tipc_node *n_ptr = l_ptr->owner;
Per Liden's avatar
Per Liden committed
613
614

		spin_lock_bh(&n_ptr->lock);
615
		tipc_link_reset(l_ptr);
Per Liden's avatar
Per Liden committed
616
617
		spin_unlock_bh(&n_ptr->lock);
	}
618
	spin_unlock_bh(&b_ptr->lock);
619
	read_unlock_bh(&tipc_net_lock);
620
	return 0;
Per Liden's avatar
Per Liden committed
621
622
623
624
}

/**
 * bearer_disable -
625
 *
626
 * Note: This routine assumes caller holds tipc_net_lock.
Per Liden's avatar
Per Liden committed
627
628
 */

629
static void bearer_disable(struct tipc_bearer *b_ptr)
Per Liden's avatar
Per Liden committed
630
631
632
633
{
	struct link *l_ptr;
	struct link *temp_l_ptr;

634
635
636
637
	info("Disabling bearer <%s>\n", b_ptr->name);
	spin_lock_bh(&b_ptr->lock);
	b_ptr->blocked = 1;
	b_ptr->media->disable_bearer(b_ptr);
Per Liden's avatar
Per Liden committed
638
	list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
639
		tipc_link_delete(l_ptr);
Per Liden's avatar
Per Liden committed
640
	}
641
642
	if (b_ptr->link_req)
		tipc_disc_delete(b_ptr->link_req);
643
644
	spin_unlock_bh(&b_ptr->lock);
	memset(b_ptr, 0, sizeof(struct tipc_bearer));
Per Liden's avatar
Per Liden committed
645
646
647
648
}

int tipc_disable_bearer(const char *name)
{
649
	struct tipc_bearer *b_ptr;
Per Liden's avatar
Per Liden committed
650
651
	int res;

652
	write_lock_bh(&tipc_net_lock);
653
654
655
656
	b_ptr = bearer_find(name);
	if (b_ptr == NULL) {
		warn("Attempt to disable unknown bearer <%s>\n", name);
		res = -EINVAL;
657
658
659
660
	} else {
		bearer_disable(b_ptr);
		res = 0;
	}
661
	write_unlock_bh(&tipc_net_lock);
Per Liden's avatar
Per Liden committed
662
663
664
665
666
	return res;
}



667
void tipc_bearer_stop(void)
Per Liden's avatar
Per Liden committed
668
669
670
671
{
	u32 i;

	for (i = 0; i < MAX_BEARERS; i++) {
672
		if (tipc_bearers[i].active)
673
			bearer_disable(&tipc_bearers[i]);
Per Liden's avatar
Per Liden committed
674
675
676
	}
	media_count = 0;
}