1 /*
2 * net/tipc/name_distr.c: TIPC name distribution code
3 *
4 * Copyright (c) 2000-2006, Ericsson AB
5 * Copyright (c) 2005, 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 "cluster.h"
39 #include "dbg.h"
40 #include "link.h"
41 #include "msg.h"
42 #include "name_distr.h"
43
44 #undef DBG_OUTPUT
45 #define DBG_OUTPUT NULL
46
47 #define ITEM_SIZE sizeof(struct distr_item)
48
49 /**
50 * struct distr_item - publication info distributed to other nodes
51 * @type: name sequence type
52 * @lower: name sequence lower bound
53 * @upper: name sequence upper bound
54 * @ref: publishing port reference
55 * @key: publication key
56 *
57 * ===> All fields are stored in network byte order. <===
58 *
59 * First 3 fields identify (name or) name sequence being published.
60 * Reference field uniquely identifies port that published name sequence.
61 * Key field uniquely identifies publication, in the event a port has
62 * multiple publications of the same name sequence.
63 *
64 * Note: There is no field that identifies the publishing node because it is
65 * the same for all items contained within a publication message.
66 */
67
68 struct distr_item {
69 __be32 type;
70 __be32 lower;
71 __be32 upper;
72 __be32 ref;
73 __be32 key;
74 };
75
76 /**
77 * List of externally visible publications by this node --
78 * that is, all publications having scope > TIPC_NODE_SCOPE.
79 */
80
81 static LIST_HEAD(publ_root);
82 static u32 publ_cnt = 0;
83
84 /**
85 * publ_to_item - add publication info to a publication message
86 */
87
88 static void publ_to_item(struct distr_item *i, struct publication *p)
89 {
90 i->type = htonl(p->type);
91 i->lower = htonl(p->lower);
92 i->upper = htonl(p->upper);
93 i->ref = htonl(p->ref);
94 i->key = htonl(p->key);
95 dbg("publ_to_item: %u, %u, %u\n", p->type, p->lower, p->upper);
96 }
97
98 /**
99 * named_prepare_buf - allocate & initialize a publication message
100 */
101
102 static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
103 {
104 struct sk_buff *buf = buf_acquire(LONG_H_SIZE + size);
105 struct tipc_msg *msg;
106
107 if (buf != NULL) {
108 msg = buf_msg(buf);
109 msg_init(msg, NAME_DISTRIBUTOR, type, TIPC_OK,
110 LONG_H_SIZE, dest);
111 msg_set_size(msg, LONG_H_SIZE + size);
112 }
113 return buf;
114 }
115
116 /**
117 * tipc_named_publish - tell other nodes about a new publication by this node
118 */
119
120 void tipc_named_publish(struct publication *publ)
121 {
122 struct sk_buff *buf;
123 struct distr_item *item;
124
125 list_add_tail(&publ->local_list, &publ_root);
126 publ_cnt++;
127
128 buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
129 if (!buf) {
130 warn("Publication distribution failure\n");
131 return;
132 }
133
134 item = (struct distr_item *)msg_data(buf_msg(buf));
135 publ_to_item(item, publ);
136 dbg("tipc_named_withdraw: broadcasting publish msg\n");
137 tipc_cltr_broadcast(buf);
138 }
139
140 /**
141 * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
142 */
143
144 void tipc_named_withdraw(struct publication *publ)
145 {
146 struct sk_buff *buf;
147 struct distr_item *item;
148
149 list_del(&publ->local_list);
150 publ_cnt--;
151
152 buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
153 if (!buf) {
154 warn("Withdrawl distribution failure\n");
155 return;
156 }
157
158 item = (struct distr_item *)msg_data(buf_msg(buf));
159 publ_to_item(item, publ);
160 dbg("tipc_named_withdraw: broadcasting withdraw msg\n");
161 tipc_cltr_broadcast(buf);
162 }
163
164 /**
165 * tipc_named_node_up - tell specified node about all publications by this node
166 */
167
168 void tipc_named_node_up(unsigned long node)
169 {
170 struct publication *publ;
171 struct distr_item *item = NULL;
172 struct sk_buff *buf = NULL;
173 u32 left = 0;
174 u32 rest;
175 u32 max_item_buf;
176
177 read_lock_bh(&tipc_nametbl_lock);
178 max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
179 max_item_buf *= ITEM_SIZE;
180 rest = publ_cnt * ITEM_SIZE;
181
182 list_for_each_entry(publ, &publ_root, local_list) {
183 if (!buf) {
184 left = (rest <= max_item_buf) ? rest : max_item_buf;
185 rest -= left;
186 buf = named_prepare_buf(PUBLICATION, left, node);
187 if (!buf) {
188 warn("Bulk publication distribution failure\n");
189 goto exit;
190 }
191 item = (struct distr_item *)msg_data(buf_msg(buf));
192 }
193 publ_to_item(item, publ);
194 item++;
195 left -= ITEM_SIZE;
196 if (!left) {
197 msg_set_link_selector(buf_msg(buf), node);
198 dbg("tipc_named_node_up: sending publish msg to "
199 "<%u.%u.%u>\n", tipc_zone(node),
200 tipc_cluster(node), tipc_node(node));
201 tipc_link_send(buf, node, node);
202 buf = NULL;
203 }
204 }
205 exit:
206 read_unlock_bh(&tipc_nametbl_lock);
207 }
208
209 /**
210 * node_is_down - remove publication associated with a failed node
211 *
212 * Invoked for each publication issued by a newly failed node.
213 * Removes publication structure from name table & deletes it.
214 * In rare cases the link may have come back up again when this
215 * function is called, and we have two items representing the same
216 * publication. Nudge this item's key to distinguish it from the other.
217 * (Note: Publication's node subscription is already unsubscribed.)
218 */
219
220 static void node_is_down(struct publication *publ)
221 {
222 struct publication *p;
223
224 write_lock_bh(&tipc_nametbl_lock);
225 dbg("node_is_down: withdrawing %u, %u, %u\n",
226 publ->type, publ->lower, publ->upper);
227 publ->key += 1222345;
228 p = tipc_nametbl_remove_publ(publ->type, publ->lower,
229 publ->node, publ->ref, publ->key);
230 write_unlock_bh(&tipc_nametbl_lock);
231
232 if (p != publ) {
233 err("Unable to remove publication from failed node\n"
234 "(type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
235 publ->type, publ->lower, publ->node, publ->ref, publ->key);
236 }
237
238 if (p) {
239 kfree(p);
240 }
241 }
242
243 /**
244 * tipc_named_recv - process name table update message sent by another node
245 */
246
247 void tipc_named_recv(struct sk_buff *buf)
248 {
249 struct publication *publ;
250 struct tipc_msg *msg = buf_msg(buf);
251 struct distr_item *item = (struct distr_item *)msg_data(msg);
252 u32 count = msg_data_sz(msg) / ITEM_SIZE;
253
254 write_lock_bh(&tipc_nametbl_lock);
255 while (count--) {
256 if (msg_type(msg) == PUBLICATION) {
257 dbg("tipc_named_recv: got publication for %u, %u, %u\n",
258 ntohl(item->type), ntohl(item->lower),
259 ntohl(item->upper));
260 publ = tipc_nametbl_insert_publ(ntohl(item->type),
261 ntohl(item->lower),
262 ntohl(item->upper),
263 TIPC_CLUSTER_SCOPE,
264 msg_orignode(msg),
265 ntohl(item->ref),
266 ntohl(item->key));
267 if (publ) {
268 tipc_nodesub_subscribe(&publ->subscr,
269 msg_orignode(msg),
270 publ,
271 (net_ev_handler)node_is_down);
272 }
273 } else if (msg_type(msg) == WITHDRAWAL) {
274 dbg("tipc_named_recv: got withdrawl for %u, %u, %u\n",
275 ntohl(item->type), ntohl(item->lower),
276 ntohl(item->upper));
277 publ = tipc_nametbl_remove_publ(ntohl(item->type),
278 ntohl(item->lower),
279 msg_orignode(msg),
280 ntohl(item->ref),
281 ntohl(item->key));
282
283 if (publ) {
284 tipc_nodesub_unsubscribe(&publ->subscr);
285 kfree(publ);
286 } else {
287 err("Unable to remove publication by node 0x%x\n"
288 "(type=%u, lower=%u, ref=%u, key=%u)\n",
289 msg_orignode(msg),
290 ntohl(item->type), ntohl(item->lower),
291 ntohl(item->ref), ntohl(item->key));
292 }
293 } else {
294 warn("Unrecognized name table message received\n");
295 }
296 item++;
297 }
298 write_unlock_bh(&tipc_nametbl_lock);
299 buf_discard(buf);
300 }
301
302 /**
303 * tipc_named_reinit - re-initialize local publication list
304 *
305 * This routine is called whenever TIPC networking is (re)enabled.
306 * All existing publications by this node that have "cluster" or "zone" scope
307 * are updated to reflect the node's current network address.
308 * (If the node's address is unchanged, the update loop terminates immediately.)
309 */
310
311 void tipc_named_reinit(void)
312 {
313 struct publication *publ;
314
315 write_lock_bh(&tipc_nametbl_lock);
316 list_for_each_entry(publ, &publ_root, local_list) {
317 if (publ->node == tipc_own_addr)
318 break;
319 publ->node = tipc_own_addr;
320 }
321 write_unlock_bh(&tipc_nametbl_lock);
322 }
323
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