summaryrefslogtreecommitdiffstats
path: root/net/tipc/name_distr.c
blob: 5718ecb91d337c1ad87e53a5fc2ebcae8a11e739 (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
/*
 * net/tipc/name_distr.c: TIPC name distribution code
 * 
 * Copyright (c) 2000-2006, Ericsson AB
 * Copyright (c) 2005, 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 "cluster.h"
#include "dbg.h"
#include "link.h"
#include "msg.h"
#include "name_distr.h"

#undef  DBG_OUTPUT
#define DBG_OUTPUT NULL

#define ITEM_SIZE sizeof(struct distr_item)

/**
 * struct distr_item - publication info distributed to other nodes
 * @type: name sequence type
 * @lower: name sequence lower bound
 * @upper: name sequence upper bound
 * @ref: publishing port reference
 * @key: publication key
 * 
 * ===> All fields are stored in network byte order. <===
 * 
 * First 3 fields identify (name or) name sequence being published.
 * Reference field uniquely identifies port that published name sequence.
 * Key field uniquely identifies publication, in the event a port has
 * multiple publications of the same name sequence.
 * 
 * Note: There is no field that identifies the publishing node because it is 
 * the same for all items contained within a publication message.
 */

struct distr_item {
	u32 type;
	u32 lower;
	u32 upper;
	u32 ref;
	u32 key;
};

/**
 * List of externally visible publications by this node -- 
 * that is, all publications having scope > TIPC_NODE_SCOPE.
 */

static LIST_HEAD(publ_root);
static u32 publ_cnt = 0;		

/**
 * publ_to_item - add publication info to a publication message
 */

static void publ_to_item(struct distr_item *i, struct publication *p)
{
	i->type = htonl(p->type);
	i->lower = htonl(p->lower);
	i->upper = htonl(p->upper);
	i->ref = htonl(p->ref);
	i->key = htonl(p->key);
	dbg("publ_to_item: %u, %u, %u\n", p->type, p->lower, p->upper);
}

/**
 * named_prepare_buf - allocate & initialize a publication message
 */

static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
{
	struct sk_buff *buf = buf_acquire(LONG_H_SIZE + size);  
	struct tipc_msg *msg;

	if (buf != NULL) {
		msg = buf_msg(buf);
		msg_init(msg, NAME_DISTRIBUTOR, type, TIPC_OK, 
			 LONG_H_SIZE, dest);
		msg_set_size(msg, LONG_H_SIZE + size);
	}
	return buf;
}

/**
 * tipc_named_publish - tell other nodes about a new publication by this node
 */

void tipc_named_publish(struct publication *publ)
{
	struct sk_buff *buf;
	struct distr_item *item;

	list_add(&publ->local_list, &publ_root);
	publ_cnt++;

	buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
	if (!buf) {
		warn("Memory squeeze; failed to distribute publication\n");
		return;
	}

	item = (struct distr_item *)msg_data(buf_msg(buf));
	publ_to_item(item, publ);
	dbg("tipc_named_withdraw: broadcasting publish msg\n");
	tipc_cltr_broadcast(buf);
}

/**
 * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 */

void tipc_named_withdraw(struct publication *publ)
{
	struct sk_buff *buf;
	struct distr_item *item;

	list_del(&publ->local_list);
	publ_cnt--;

	buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
	if (!buf) {
		warn("Memory squeeze; failed to distribute withdrawal\n");
		return;
	}

	item = (struct distr_item *)msg_data(buf_msg(buf));
	publ_to_item(item, publ);
	dbg("tipc_named_withdraw: broadcasting withdraw msg\n");
	tipc_cltr_broadcast(buf);
}

/**
 * tipc_named_node_up - tell specified node about all publications by this node
 */

void tipc_named_node_up(unsigned long node)
{
	struct publication *publ;
	struct distr_item *item = NULL;
	struct sk_buff *buf = NULL;
	u32 left = 0;
	u32 rest;
	u32 max_item_buf;

	read_lock_bh(&tipc_nametbl_lock); 
	max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
	max_item_buf *= ITEM_SIZE;
	rest = publ_cnt * ITEM_SIZE;

	list_for_each_entry(publ, &publ_root, local_list) {
		if (!buf) {
			left = (rest <= max_item_buf) ? rest : max_item_buf;
			rest -= left;
			buf = named_prepare_buf(PUBLICATION, left, node);       
			if (buf == NULL) {
				warn("Memory Squeeze; could not send publication\n");
				goto exit;
			}
			item = (struct distr_item *)msg_data(buf_msg(buf));
		}
		publ_to_item(item, publ);
		item++;
		left -= ITEM_SIZE;
		if (!left) {
			msg_set_link_selector(buf_msg(buf), node);
			dbg("tipc_named_node_up: sending publish msg to "
			    "<%u.%u.%u>\n", tipc_zone(node), 
			    tipc_cluster(node), tipc_node(node));
			tipc_link_send(buf, node, node);
			buf = NULL;
		}
	}
exit:
	read_unlock_bh(&tipc_nametbl_lock); 
}

/**
 * node_is_down - remove publication associated with a failed node
 * 
 * Invoked for each publication issued by a newly failed node.  
 * Removes publication structure from name table & deletes it.
 * In rare cases the link may have come back up again when this
 * function is called, and we have two items representing the same
 * publication. Nudge this item's key to distinguish it from the other.
 * (Note: Publication's node subscription is already unsubscribed.)
 */

static void node_is_down(struct publication *publ)
{
	struct publication *p;

        write_lock_bh(&tipc_nametbl_lock);
	dbg("node_is_down: withdrawing %u, %u, %u\n", 
	    publ->type, publ->lower, publ->upper);
        publ->key += 1222345;
	p = tipc_nametbl_remove_publ(publ->type, publ->lower, 
				     publ->node, publ->ref, publ->key);
	write_unlock_bh(&tipc_nametbl_lock);

        if (p != publ) {
		err("Unable to remove publication from failed node\n"
		    "(type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
		    publ->type, publ->lower, publ->node, publ->ref, publ->key);
	}

	if (p) {
		kfree(p);
	}
}

/**
 * tipc_named_recv - process name table update message sent by another node
 */

void tipc_named_recv(struct sk_buff *buf)
{
	struct publication *publ;
	struct tipc_msg *msg = buf_msg(buf);
	struct distr_item *item = (struct distr_item *)msg_data(msg);
	u32 count = msg_data_sz(msg) / ITEM_SIZE;

	write_lock_bh(&tipc_nametbl_lock); 
	while (count--) {
		if (msg_type(msg) == PUBLICATION) {
			dbg("tipc_named_recv: got publication for %u, %u, %u\n", 
			    ntohl(item->type), ntohl(item->lower),
			    ntohl(item->upper));
			publ = tipc_nametbl_insert_publ(ntohl(item->type), 
							ntohl(item->lower),
							ntohl(item->upper),
							TIPC_CLUSTER_SCOPE,
							msg_orignode(msg), 
							ntohl(item->ref),
							ntohl(item->key));
			if (publ) {
				tipc_nodesub_subscribe(&publ->subscr, 
						       msg_orignode(msg), 
						       publ,
						       (net_ev_handler)node_is_down);
			}
		} else if (msg_type(msg) == WITHDRAWAL) {
			dbg("tipc_named_recv: got withdrawl for %u, %u, %u\n", 
			    ntohl(item->type), ntohl(item->lower),
			    ntohl(item->upper));
			publ = tipc_nametbl_remove_publ(ntohl(item->type),
							ntohl(item->lower),
							msg_orignode(msg),
							ntohl(item->ref),
							ntohl(item->key));

			if (publ) {
				tipc_nodesub_unsubscribe(&publ->subscr);
        			kfree(publ);
			} else {
				err("Unable to remove publication by node 0x%x\n"
				    "(type=%u, lower=%u, ref=%u, key=%u)\n",
				    msg_orignode(msg),
				    ntohl(item->type), ntohl(item->lower),
				    ntohl(item->ref), ntohl(item->key));
			}
		} else {
			warn("tipc_named_recv: unknown msg\n");
		}
		item++;
	}
	write_unlock_bh(&tipc_nametbl_lock); 
	buf_discard(buf);
}

/**
 * tipc_named_reinit - re-initialize local publication list
 * 
 * This routine is called whenever TIPC networking is (re)enabled.
 * All existing publications by this node that have "cluster" or "zone" scope
 * are updated to reflect the node's current network address.
 * (If the node's address is unchanged, the update loop terminates immediately.)
 */

void tipc_named_reinit(void)
{
	struct publication *publ;

	write_lock_bh(&tipc_nametbl_lock); 
	list_for_each_entry(publ, &publ_root, local_list) {
		if (publ->node == tipc_own_addr)
			break;
		publ->node = tipc_own_addr;
	}
	write_unlock_bh(&tipc_nametbl_lock); 
}