Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux...
[linux-2.6] / net / tipc / name_distr.c
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 #define ITEM_SIZE sizeof(struct distr_item)
45
46 /**
47  * struct distr_item - publication info distributed to other nodes
48  * @type: name sequence type
49  * @lower: name sequence lower bound
50  * @upper: name sequence upper bound
51  * @ref: publishing port reference
52  * @key: publication key
53  *
54  * ===> All fields are stored in network byte order. <===
55  *
56  * First 3 fields identify (name or) name sequence being published.
57  * Reference field uniquely identifies port that published name sequence.
58  * Key field uniquely identifies publication, in the event a port has
59  * multiple publications of the same name sequence.
60  *
61  * Note: There is no field that identifies the publishing node because it is
62  * the same for all items contained within a publication message.
63  */
64
65 struct distr_item {
66         __be32 type;
67         __be32 lower;
68         __be32 upper;
69         __be32 ref;
70         __be32 key;
71 };
72
73 /**
74  * List of externally visible publications by this node --
75  * that is, all publications having scope > TIPC_NODE_SCOPE.
76  */
77
78 static LIST_HEAD(publ_root);
79 static u32 publ_cnt = 0;
80
81 /**
82  * publ_to_item - add publication info to a publication message
83  */
84
85 static void publ_to_item(struct distr_item *i, struct publication *p)
86 {
87         i->type = htonl(p->type);
88         i->lower = htonl(p->lower);
89         i->upper = htonl(p->upper);
90         i->ref = htonl(p->ref);
91         i->key = htonl(p->key);
92         dbg("publ_to_item: %u, %u, %u\n", p->type, p->lower, p->upper);
93 }
94
95 /**
96  * named_prepare_buf - allocate & initialize a publication message
97  */
98
99 static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
100 {
101         struct sk_buff *buf = buf_acquire(LONG_H_SIZE + size);
102         struct tipc_msg *msg;
103
104         if (buf != NULL) {
105                 msg = buf_msg(buf);
106                 msg_init(msg, NAME_DISTRIBUTOR, type, LONG_H_SIZE, dest);
107                 msg_set_size(msg, LONG_H_SIZE + size);
108         }
109         return buf;
110 }
111
112 /**
113  * tipc_named_publish - tell other nodes about a new publication by this node
114  */
115
116 void tipc_named_publish(struct publication *publ)
117 {
118         struct sk_buff *buf;
119         struct distr_item *item;
120
121         list_add_tail(&publ->local_list, &publ_root);
122         publ_cnt++;
123
124         buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
125         if (!buf) {
126                 warn("Publication distribution failure\n");
127                 return;
128         }
129
130         item = (struct distr_item *)msg_data(buf_msg(buf));
131         publ_to_item(item, publ);
132         dbg("tipc_named_withdraw: broadcasting publish msg\n");
133         tipc_cltr_broadcast(buf);
134 }
135
136 /**
137  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
138  */
139
140 void tipc_named_withdraw(struct publication *publ)
141 {
142         struct sk_buff *buf;
143         struct distr_item *item;
144
145         list_del(&publ->local_list);
146         publ_cnt--;
147
148         buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
149         if (!buf) {
150                 warn("Withdrawl distribution failure\n");
151                 return;
152         }
153
154         item = (struct distr_item *)msg_data(buf_msg(buf));
155         publ_to_item(item, publ);
156         dbg("tipc_named_withdraw: broadcasting withdraw msg\n");
157         tipc_cltr_broadcast(buf);
158 }
159
160 /**
161  * tipc_named_node_up - tell specified node about all publications by this node
162  */
163
164 void tipc_named_node_up(unsigned long node)
165 {
166         struct publication *publ;
167         struct distr_item *item = NULL;
168         struct sk_buff *buf = NULL;
169         u32 left = 0;
170         u32 rest;
171         u32 max_item_buf;
172
173         read_lock_bh(&tipc_nametbl_lock);
174         max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
175         max_item_buf *= ITEM_SIZE;
176         rest = publ_cnt * ITEM_SIZE;
177
178         list_for_each_entry(publ, &publ_root, local_list) {
179                 if (!buf) {
180                         left = (rest <= max_item_buf) ? rest : max_item_buf;
181                         rest -= left;
182                         buf = named_prepare_buf(PUBLICATION, left, node);
183                         if (!buf) {
184                                 warn("Bulk publication distribution failure\n");
185                                 goto exit;
186                         }
187                         item = (struct distr_item *)msg_data(buf_msg(buf));
188                 }
189                 publ_to_item(item, publ);
190                 item++;
191                 left -= ITEM_SIZE;
192                 if (!left) {
193                         msg_set_link_selector(buf_msg(buf), node);
194                         dbg("tipc_named_node_up: sending publish msg to "
195                             "<%u.%u.%u>\n", tipc_zone(node),
196                             tipc_cluster(node), tipc_node(node));
197                         tipc_link_send(buf, node, node);
198                         buf = NULL;
199                 }
200         }
201 exit:
202         read_unlock_bh(&tipc_nametbl_lock);
203 }
204
205 /**
206  * node_is_down - remove publication associated with a failed node
207  *
208  * Invoked for each publication issued by a newly failed node.
209  * Removes publication structure from name table & deletes it.
210  * In rare cases the link may have come back up again when this
211  * function is called, and we have two items representing the same
212  * publication. Nudge this item's key to distinguish it from the other.
213  * (Note: Publication's node subscription is already unsubscribed.)
214  */
215
216 static void node_is_down(struct publication *publ)
217 {
218         struct publication *p;
219
220         write_lock_bh(&tipc_nametbl_lock);
221         dbg("node_is_down: withdrawing %u, %u, %u\n",
222             publ->type, publ->lower, publ->upper);
223         publ->key += 1222345;
224         p = tipc_nametbl_remove_publ(publ->type, publ->lower,
225                                      publ->node, publ->ref, publ->key);
226         write_unlock_bh(&tipc_nametbl_lock);
227
228         if (p != publ) {
229                 err("Unable to remove publication from failed node\n"
230                     "(type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
231                     publ->type, publ->lower, publ->node, publ->ref, publ->key);
232         }
233
234         if (p) {
235                 kfree(p);
236         }
237 }
238
239 /**
240  * tipc_named_recv - process name table update message sent by another node
241  */
242
243 void tipc_named_recv(struct sk_buff *buf)
244 {
245         struct publication *publ;
246         struct tipc_msg *msg = buf_msg(buf);
247         struct distr_item *item = (struct distr_item *)msg_data(msg);
248         u32 count = msg_data_sz(msg) / ITEM_SIZE;
249
250         write_lock_bh(&tipc_nametbl_lock);
251         while (count--) {
252                 if (msg_type(msg) == PUBLICATION) {
253                         dbg("tipc_named_recv: got publication for %u, %u, %u\n",
254                             ntohl(item->type), ntohl(item->lower),
255                             ntohl(item->upper));
256                         publ = tipc_nametbl_insert_publ(ntohl(item->type),
257                                                         ntohl(item->lower),
258                                                         ntohl(item->upper),
259                                                         TIPC_CLUSTER_SCOPE,
260                                                         msg_orignode(msg),
261                                                         ntohl(item->ref),
262                                                         ntohl(item->key));
263                         if (publ) {
264                                 tipc_nodesub_subscribe(&publ->subscr,
265                                                        msg_orignode(msg),
266                                                        publ,
267                                                        (net_ev_handler)node_is_down);
268                         }
269                 } else if (msg_type(msg) == WITHDRAWAL) {
270                         dbg("tipc_named_recv: got withdrawl for %u, %u, %u\n",
271                             ntohl(item->type), ntohl(item->lower),
272                             ntohl(item->upper));
273                         publ = tipc_nametbl_remove_publ(ntohl(item->type),
274                                                         ntohl(item->lower),
275                                                         msg_orignode(msg),
276                                                         ntohl(item->ref),
277                                                         ntohl(item->key));
278
279                         if (publ) {
280                                 tipc_nodesub_unsubscribe(&publ->subscr);
281                                 kfree(publ);
282                         } else {
283                                 err("Unable to remove publication by node 0x%x\n"
284                                     "(type=%u, lower=%u, ref=%u, key=%u)\n",
285                                     msg_orignode(msg),
286                                     ntohl(item->type), ntohl(item->lower),
287                                     ntohl(item->ref), ntohl(item->key));
288                         }
289                 } else {
290                         warn("Unrecognized name table message received\n");
291                 }
292                 item++;
293         }
294         write_unlock_bh(&tipc_nametbl_lock);
295         buf_discard(buf);
296 }
297
298 /**
299  * tipc_named_reinit - re-initialize local publication list
300  *
301  * This routine is called whenever TIPC networking is (re)enabled.
302  * All existing publications by this node that have "cluster" or "zone" scope
303  * are updated to reflect the node's current network address.
304  * (If the node's address is unchanged, the update loop terminates immediately.)
305  */
306
307 void tipc_named_reinit(void)
308 {
309         struct publication *publ;
310
311         write_lock_bh(&tipc_nametbl_lock);
312         list_for_each_entry(publ, &publ_root, local_list) {
313                 if (publ->node == tipc_own_addr)
314                         break;
315                 publ->node = tipc_own_addr;
316         }
317         write_unlock_bh(&tipc_nametbl_lock);
318 }