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