name_distr.c revision 3175bd9add570f3b5c06877369897b334556a2ff 
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
62struct 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
75static LIST_HEAD(publ_root);
76static u32 publ_cnt;
77
78/**
79 * publ_to_item - add publication info to a publication message
80 */
81
82static 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
95static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
96{
97	struct sk_buff *buf = tipc_buf_acquire(INT_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, INT_H_SIZE, dest);
103		msg_set_size(msg, INT_H_SIZE + size);
104	}
105	return buf;
106}
107
108static 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
130void 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
153void 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
176void tipc_named_node_up(unsigned long nodearg)
177{
178	struct tipc_node *n_ptr;
179	struct tipc_link *l_ptr;
180	struct publication *publ;
181	struct distr_item *item = NULL;
182	struct sk_buff *buf = NULL;
183	struct list_head message_list;
184	u32 node = (u32)nodearg;
185	u32 left = 0;
186	u32 rest;
187	u32 max_item_buf = 0;
188
189	/* compute maximum amount of publication data to send per message */
190
191	read_lock_bh(&tipc_net_lock);
192	n_ptr = tipc_node_find(node);
193	if (n_ptr) {
194		tipc_node_lock(n_ptr);
195		l_ptr = n_ptr->active_links[0];
196		if (l_ptr)
197			max_item_buf = ((l_ptr->max_pkt - INT_H_SIZE) /
198				ITEM_SIZE) * ITEM_SIZE;
199		tipc_node_unlock(n_ptr);
200	}
201	read_unlock_bh(&tipc_net_lock);
202	if (!max_item_buf)
203		return;
204
205	/* create list of publication messages, then send them as a unit */
206
207	INIT_LIST_HEAD(&message_list);
208
209	read_lock_bh(&tipc_nametbl_lock);
210	rest = publ_cnt * ITEM_SIZE;
211
212	list_for_each_entry(publ, &publ_root, local_list) {
213		if (!buf) {
214			left = (rest <= max_item_buf) ? rest : max_item_buf;
215			rest -= left;
216			buf = named_prepare_buf(PUBLICATION, left, node);
217			if (!buf) {
218				warn("Bulk publication distribution failure\n");
219				goto exit;
220			}
221			item = (struct distr_item *)msg_data(buf_msg(buf));
222		}
223		publ_to_item(item, publ);
224		item++;
225		left -= ITEM_SIZE;
226		if (!left) {
227			list_add_tail((struct list_head *)buf, &message_list);
228			buf = NULL;
229		}
230	}
231exit:
232	read_unlock_bh(&tipc_nametbl_lock);
233
234	tipc_link_send_names(&message_list, (u32)node);
235}
236
237/**
238 * named_purge_publ - remove publication associated with a failed node
239 *
240 * Invoked for each publication issued by a newly failed node.
241 * Removes publication structure from name table & deletes it.
242 */
243
244static void named_purge_publ(struct publication *publ)
245{
246	struct publication *p;
247
248	write_lock_bh(&tipc_nametbl_lock);
249	p = tipc_nametbl_remove_publ(publ->type, publ->lower,
250				     publ->node, publ->ref, publ->key);
251	if (p)
252		tipc_nodesub_unsubscribe(&p->subscr);
253	write_unlock_bh(&tipc_nametbl_lock);
254
255	if (p != publ) {
256		err("Unable to remove publication from failed node\n"
257		    "(type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
258		    publ->type, publ->lower, publ->node, publ->ref, publ->key);
259	}
260
261	kfree(p);
262}
263
264/**
265 * tipc_named_recv - process name table update message sent by another node
266 */
267
268void tipc_named_recv(struct sk_buff *buf)
269{
270	struct publication *publ;
271	struct tipc_msg *msg = buf_msg(buf);
272	struct distr_item *item = (struct distr_item *)msg_data(msg);
273	u32 count = msg_data_sz(msg) / ITEM_SIZE;
274
275	write_lock_bh(&tipc_nametbl_lock);
276	while (count--) {
277		if (msg_type(msg) == PUBLICATION) {
278			publ = tipc_nametbl_insert_publ(ntohl(item->type),
279							ntohl(item->lower),
280							ntohl(item->upper),
281							TIPC_CLUSTER_SCOPE,
282							msg_orignode(msg),
283							ntohl(item->ref),
284							ntohl(item->key));
285			if (publ) {
286				tipc_nodesub_subscribe(&publ->subscr,
287						       msg_orignode(msg),
288						       publ,
289						       (net_ev_handler)
290						       named_purge_publ);
291			}
292		} else if (msg_type(msg) == WITHDRAWAL) {
293			publ = tipc_nametbl_remove_publ(ntohl(item->type),
294							ntohl(item->lower),
295							msg_orignode(msg),
296							ntohl(item->ref),
297							ntohl(item->key));
298
299			if (publ) {
300				tipc_nodesub_unsubscribe(&publ->subscr);
301				kfree(publ);
302			} else {
303				err("Unable to remove publication by node 0x%x\n"
304				    "(type=%u, lower=%u, ref=%u, key=%u)\n",
305				    msg_orignode(msg),
306				    ntohl(item->type), ntohl(item->lower),
307				    ntohl(item->ref), ntohl(item->key));
308			}
309		} else {
310			warn("Unrecognized name table message received\n");
311		}
312		item++;
313	}
314	write_unlock_bh(&tipc_nametbl_lock);
315	buf_discard(buf);
316}
317
318/**
319 * tipc_named_reinit - re-initialize local publication list
320 *
321 * This routine is called whenever TIPC networking is enabled.
322 * All existing publications by this node that have "cluster" or "zone" scope
323 * are updated to reflect the node's new network address.
324 */
325
326void tipc_named_reinit(void)
327{
328	struct publication *publ;
329
330	write_lock_bh(&tipc_nametbl_lock);
331
332	list_for_each_entry(publ, &publ_root, local_list)
333		publ->node = tipc_own_addr;
334
335	write_unlock_bh(&tipc_nametbl_lock);
336}
337