Root/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
65struct 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
78static LIST_HEAD(publ_root);
79static u32 publ_cnt = 0;
80
81/**
82 * publ_to_item - add publication info to a publication message
83 */
84
85static 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
99static 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
116void 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
140void 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
164void 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    }
201exit:
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
216static 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
243void 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
307void 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}
319

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