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		tipc_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