aboutsummaryrefslogtreecommitdiff
path: root/net/tipc/node.c
blob: 2d106ef4fa4cca43970f0e2dc6bc925ccf12ea95 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
/*
 * net/tipc/node.c: TIPC node management routines
 *
 * Copyright (c) 2000-2006, Ericsson AB
 * Copyright (c) 2005-2006, 2010-2011, Wind River Systems
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 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.
 *
 * 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
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "core.h"
#include "config.h"
#include "node.h"
#include "name_distr.h"

static void node_lost_contact(struct tipc_node *n_ptr);
static void node_established_contact(struct tipc_node *n_ptr);

static DEFINE_SPINLOCK(node_create_lock);

static struct hlist_head node_htable[NODE_HTABLE_SIZE];
LIST_HEAD(tipc_node_list);
static u32 tipc_num_nodes;

static atomic_t tipc_num_links = ATOMIC_INIT(0);
u32 tipc_own_tag;

/**
 * tipc_node_find - locate specified node object, if it exists
 */

struct tipc_node *tipc_node_find(u32 addr)
{
	struct tipc_node *node;
	struct hlist_node *pos;

	if (unlikely(!in_own_cluster(addr)))
		return NULL;

	hlist_for_each_entry(node, pos, &node_htable[tipc_hashfn(addr)], hash) {
		if (node->addr == addr)
			return node;
	}
	return NULL;
}

/**
 * tipc_node_create - create neighboring node
 *
 * Currently, this routine is called by neighbor discovery code, which holds
 * net_lock for reading only.  We must take node_create_lock to ensure a node
 * isn't created twice if two different bearers discover the node at the same
 * time.  (It would be preferable to switch to holding net_lock in write mode,
 * but this is a non-trivial change.)
 */

struct tipc_node *tipc_node_create(u32 addr)
{
	struct tipc_node *n_ptr, *temp_node;

	spin_lock_bh(&node_create_lock);

	n_ptr = tipc_node_find(addr);
	if (n_ptr) {
		spin_unlock_bh(&node_create_lock);
		return n_ptr;
	}

	n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
	if (!n_ptr) {
		spin_unlock_bh(&node_create_lock);
		warn("Node creation failed, no memory\n");
		return NULL;
	}

	n_ptr->addr = addr;
	spin_lock_init(&n_ptr->lock);
	INIT_HLIST_NODE(&n_ptr->hash);
	INIT_LIST_HEAD(&n_ptr->list);
	INIT_LIST_HEAD(&n_ptr->nsub);

	hlist_add_head(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);

	list_for_each_entry(temp_node, &tipc_node_list, list) {
		if (n_ptr->addr < temp_node->addr)
			break;
	}
	list_add_tail(&n_ptr->list, &temp_node->list);

	tipc_num_nodes++;

	spin_unlock_bh(&node_create_lock);
	return n_ptr;
}

void tipc_node_delete(struct tipc_node *n_ptr)
{
	list_del(&n_ptr->list);
	hlist_del(&n_ptr->hash);
	kfree(n_ptr);

	tipc_num_nodes--;
}


/**
 * tipc_node_link_up - handle addition of link
 *
 * Link becomes active (alone or shared) or standby, depending on its priority.
 */

void tipc_node_link_up(struct tipc_node *n_ptr, struct link *l_ptr)
{
	struct link **active = &n_ptr->active_links[0];

	n_ptr->working_links++;

	info("Established link <%s> on network plane %c\n",
	     l_ptr->name, l_ptr->b_ptr->net_plane);

	if (!active[0]) {
		active[0] = active[1] = l_ptr;
		node_established_contact(n_ptr);
		return;
	}
	if (l_ptr->priority < active[0]->priority) {
		info("New link <%s> becomes standby\n", l_ptr->name);
		return;
	}
	tipc_link_send_duplicate(active[0], l_ptr);
	if (l_ptr->priority == active[0]->priority) {
		active[0] = l_ptr;
		return;
	}
	info("Old link <%s> becomes standby\n", active[0]->name);
	if (active[1] != active[0])
		info("Old link <%s> becomes standby\n", active[1]->name);
	active[0] = active[1] = l_ptr;
}

/**
 * node_select_active_links - select active link
 */

static void node_select_active_links(struct tipc_node *n_ptr)
{
	struct link **active = &n_ptr->active_links[0];
	u32 i;
	u32 highest_prio = 0;

	active[0] = active[1] = NULL;

	for (i = 0; i < MAX_BEARERS; i++) {
		struct link *l_ptr = n_ptr->links[i];

		if (!l_ptr || !tipc_link_is_up(l_ptr) ||
		    (l_ptr->priority < highest_prio))
			continue;

		if (l_ptr->priority > highest_prio) {
			highest_prio = l_ptr->priority;
			active[0] = active[1] = l_ptr;
		} else {
			active[1] = l_ptr;
		}
	}
}

/**
 * tipc_node_link_down - handle loss of link
 */

void tipc_node_link_down(struct tipc_node *n_ptr, struct link *l_ptr)
{
	struct link **active;

	n_ptr->working_links--;

	if (!tipc_link_is_active(l_ptr)) {
		info("Lost standby link <%s> on network plane %c\n",
		     l_ptr->name, l_ptr->b_ptr->net_plane);
		return;
	}
	info("Lost link <%s> on network plane %c\n",
		l_ptr->name, l_ptr->b_ptr->net_plane);

	active = &n_ptr->active_links[0];
	if (active[0] == l_ptr)
		active[0] = active[1];
	if (active[1] == l_ptr)
		active[1] = active[0];
	if (active[0] == l_ptr)
		node_select_active_links(n_ptr);
	if (tipc_node_is_up(n_ptr))
		tipc_link_changeover(l_ptr);
	else
		node_lost_contact(n_ptr);
}

int tipc_node_active_links(struct tipc_node *n_ptr)
{
	return n_ptr->active_links[0] != NULL;
}

int tipc_node_redundant_links(struct tipc_node *n_ptr)
{
	return n_ptr->working_links > 1;
}

int tipc_node_is_up(struct tipc_node *n_ptr)
{
	return tipc_node_active_links(n_ptr);
}

void tipc_node_attach_link(struct tipc_node *n_ptr, struct link *l_ptr)
{
	n_ptr->links[l_ptr->b_ptr->identity] = l_ptr;
	atomic_inc(&tipc_num_links);
	n_ptr->link_cnt++;
}

void tipc_node_detach_link(struct tipc_node *n_ptr, struct link *l_ptr)
{
	n_ptr->links[l_ptr->b_ptr->identity] = NULL;
	atomic_dec(&tipc_num_links);
	n_ptr->link_cnt--;
}

/*
 * Routing table management - five cases to handle:
 *
 * 1: A link towards a zone/cluster external node comes up.
 *    => Send a multicast message updating routing tables of all
 *    system nodes within own cluster that the new destination
 *    can be reached via this node.
 *    (node.establishedContact()=>cluster.multicastNewRoute())
 *
 * 2: A link towards a slave node comes up.
 *    => Send a multicast message updating routing tables of all
 *    system nodes within own cluster that the new destination
 *    can be reached via this node.
 *    (node.establishedContact()=>cluster.multicastNewRoute())
 *    => Send a  message to the slave node about existence
 *    of all system nodes within cluster:
 *    (node.establishedContact()=>cluster.sendLocalRoutes())
 *
 * 3: A new cluster local system node becomes available.
 *    => Send message(s) to this particular node containing
 *    information about all cluster external and slave
 *     nodes which can be reached via this node.
 *    (node.establishedContact()==>network.sendExternalRoutes())
 *    (node.establishedContact()==>network.sendSlaveRoutes())
 *    => Send messages to all directly connected slave nodes
 *    containing information about the existence of the new node
 *    (node.establishedContact()=>cluster.multicastNewRoute())
 *
 * 4: The link towards a zone/cluster external node or slave
 *    node goes down.
 *    => Send a multcast message updating routing tables of all
 *    nodes within cluster that the new destination can not any
 *    longer be reached via this node.
 *    (node.lostAllLinks()=>cluster.bcastLostRoute())
 *
 * 5: A cluster local system node becomes unavailable.
 *    => Remove all references to this node from the local
 *    routing tables. Note: This is a completely node
 *    local operation.
 *    (node.lostAllLinks()=>network.removeAsRouter())
 *    => Send messages to all directly connected slave nodes
 *    containing information about loss of the node
 *    (node.establishedContact()=>cluster.multicastLostRoute())
 *
 */

static void node_established_contact(struct tipc_node *n_ptr)
{
	tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr);

	/* Syncronize broadcast acks */
	n_ptr->bclink.acked = tipc_bclink_get_last_sent();

	if (n_ptr->bclink.supported) {
		tipc_nmap_add(&tipc_bcast_nmap, n_ptr->addr);
		if (n_ptr->addr < tipc_own_addr)
			tipc_own_tag++;
	}
}

static void node_cleanup_finished(unsigned long node_addr)
{
	struct tipc_node *n_ptr;

	read_lock_bh(&tipc_net_lock);
	n_ptr = tipc_node_find(node_addr);
	if (n_ptr) {
		tipc_node_lock(n_ptr);
		n_ptr->cleanup_required = 0;
		tipc_node_unlock(n_ptr);
	}
	read_unlock_bh(&tipc_net_lock);
}

static void node_lost_contact(struct tipc_node *n_ptr)
{
	char addr_string[16];
	u32 i;

	/* Clean up broadcast reception remains */
	n_ptr->bclink.gap_after = n_ptr->bclink.gap_to = 0;
	while (n_ptr->bclink.deferred_head) {
		struct sk_buff *buf = n_ptr->bclink.deferred_head;
		n_ptr->bclink.deferred_head = buf->next;
		buf_discard(buf);
	}
	if (n_ptr->bclink.defragm) {
		buf_discard(n_ptr->bclink.defragm);
		n_ptr->bclink.defragm = NULL;
	}

	if (n_ptr->bclink.supported) {
		tipc_bclink_acknowledge(n_ptr,
					mod(n_ptr->bclink.acked + 10000));
		tipc_nmap_remove(&tipc_bcast_nmap, n_ptr->addr);
		if (n_ptr->addr < tipc_own_addr)
			tipc_own_tag--;
	}

	info("Lost contact with %s\n",
	     tipc_addr_string_fill(addr_string, n_ptr->addr));

	/* Abort link changeover */
	for (i = 0; i < MAX_BEARERS; i++) {
		struct link *l_ptr = n_ptr->links[i];
		if (!l_ptr)
			continue;
		l_ptr->reset_checkpoint = l_ptr->next_in_no;
		l_ptr->exp_msg_count = 0;
		tipc_link_reset_fragments(l_ptr);
	}

	/* Notify subscribers */
	tipc_nodesub_notify(n_ptr);

	/* Prevent re-contact with node until all cleanup is done */

	n_ptr->cleanup_required = 1;
	tipc_k_signal((Handler)node_cleanup_finished, n_ptr->addr);
}

struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
{
	u32 domain;
	struct sk_buff *buf;
	struct tipc_node *n_ptr;
	struct tipc_node_info node_info;
	u32 payload_size;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (!tipc_addr_domain_valid(domain))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (network address)");

	read_lock_bh(&tipc_net_lock);
	if (!tipc_num_nodes) {
		read_unlock_bh(&tipc_net_lock);
		return tipc_cfg_reply_none();
	}

	/* For now, get space for all other nodes */

	payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
	if (payload_size > 32768u) {
		read_unlock_bh(&tipc_net_lock);
		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
						   " (too many nodes)");
	}
	buf = tipc_cfg_reply_alloc(payload_size);
	if (!buf) {
		read_unlock_bh(&tipc_net_lock);
		return NULL;
	}

	/* Add TLVs for all nodes in scope */

	list_for_each_entry(n_ptr, &tipc_node_list, list) {
		if (!tipc_in_scope(domain, n_ptr->addr))
			continue;
		node_info.addr = htonl(n_ptr->addr);
		node_info.up = htonl(tipc_node_is_up(n_ptr));
		tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
				    &node_info, sizeof(node_info));
	}

	read_unlock_bh(&tipc_net_lock);
	return buf;
}

struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
{
	u32 domain;
	struct sk_buff *buf;
	struct tipc_node *n_ptr;
	struct tipc_link_info link_info;
	u32 payload_size;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (!tipc_addr_domain_valid(domain))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (network address)");

	if (tipc_mode != TIPC_NET_MODE)
		return tipc_cfg_reply_none();

	read_lock_bh(&tipc_net_lock);

	/* Get space for all unicast links + multicast link */

	payload_size = TLV_SPACE(sizeof(link_info)) *
		(atomic_read(&tipc_num_links) + 1);
	if (payload_size > 32768u) {
		read_unlock_bh(&tipc_net_lock);
		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
						   " (too many links)");
	}
	buf = tipc_cfg_reply_alloc(payload_size);
	if (!buf) {
		read_unlock_bh(&tipc_net_lock);
		return NULL;
	}

	/* Add TLV for broadcast link */

	link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
	link_info.up = htonl(1);
	strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
	tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));

	/* Add TLVs for any other links in scope */

	list_for_each_entry(n_ptr, &tipc_node_list, list) {
		u32 i;

		if (!tipc_in_scope(domain, n_ptr->addr))
			continue;
		tipc_node_lock(n_ptr);
		for (i = 0; i < MAX_BEARERS; i++) {
			if (!n_ptr->links[i])
				continue;
			link_info.dest = htonl(n_ptr->addr);
			link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
			strcpy(link_info.str, n_ptr->links[i]->name);
			tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
					    &link_info, sizeof(link_info));
		}
		tipc_node_unlock(n_ptr);
	}

	read_unlock_bh(&tipc_net_lock);
	return buf;
}