1/*
2 * net/tipc/name_distr.c: TIPC name distribution code
3 *
4 * Copyright (c) 2000-2006, 2014, 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/**
42 * struct publ_list - list of publications made by this node
43 * @list: circular list of publications
44 * @list_size: number of entries in list
45 */
46struct publ_list {
47	struct list_head list;
48	u32 size;
49};
50
51static struct publ_list publ_zone = {
52	.list = LIST_HEAD_INIT(publ_zone.list),
53	.size = 0,
54};
55
56static struct publ_list publ_cluster = {
57	.list = LIST_HEAD_INIT(publ_cluster.list),
58	.size = 0,
59};
60
61static struct publ_list publ_node = {
62	.list = LIST_HEAD_INIT(publ_node.list),
63	.size = 0,
64};
65
66static struct publ_list *publ_lists[] = {
67	NULL,
68	&publ_zone,	/* publ_lists[TIPC_ZONE_SCOPE]		*/
69	&publ_cluster,	/* publ_lists[TIPC_CLUSTER_SCOPE]	*/
70	&publ_node	/* publ_lists[TIPC_NODE_SCOPE]		*/
71};
72
73
74int sysctl_tipc_named_timeout __read_mostly = 2000;
75
76/**
77 * struct tipc_dist_queue - queue holding deferred name table updates
78 */
79static struct list_head tipc_dist_queue = LIST_HEAD_INIT(tipc_dist_queue);
80
81struct distr_queue_item {
82	struct distr_item i;
83	u32 dtype;
84	u32 node;
85	unsigned long expires;
86	struct list_head next;
87};
88
89/**
90 * publ_to_item - add publication info to a publication message
91 */
92static void publ_to_item(struct distr_item *i, struct publication *p)
93{
94	i->type = htonl(p->type);
95	i->lower = htonl(p->lower);
96	i->upper = htonl(p->upper);
97	i->ref = htonl(p->ref);
98	i->key = htonl(p->key);
99}
100
101/**
102 * named_prepare_buf - allocate & initialize a publication message
103 */
104static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
105{
106	struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size);
107	struct tipc_msg *msg;
108
109	if (buf != NULL) {
110		msg = buf_msg(buf);
111		tipc_msg_init(msg, NAME_DISTRIBUTOR, type, INT_H_SIZE, dest);
112		msg_set_size(msg, INT_H_SIZE + size);
113	}
114	return buf;
115}
116
117void named_cluster_distribute(struct sk_buff *buf)
118{
119	struct sk_buff *obuf;
120	struct tipc_node *node;
121	u32 dnode;
122
123	rcu_read_lock();
124	list_for_each_entry_rcu(node, &tipc_node_list, list) {
125		dnode = node->addr;
126		if (in_own_node(dnode))
127			continue;
128		if (!tipc_node_active_links(node))
129			continue;
130		obuf = skb_copy(buf, GFP_ATOMIC);
131		if (!obuf)
132			break;
133		msg_set_destnode(buf_msg(obuf), dnode);
134		tipc_link_xmit(obuf, dnode, dnode);
135	}
136	rcu_read_unlock();
137
138	kfree_skb(buf);
139}
140
141/**
142 * tipc_named_publish - tell other nodes about a new publication by this node
143 */
144struct sk_buff *tipc_named_publish(struct publication *publ)
145{
146	struct sk_buff *buf;
147	struct distr_item *item;
148
149	list_add_tail(&publ->local_list, &publ_lists[publ->scope]->list);
150	publ_lists[publ->scope]->size++;
151
152	if (publ->scope == TIPC_NODE_SCOPE)
153		return NULL;
154
155	buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
156	if (!buf) {
157		pr_warn("Publication distribution failure\n");
158		return NULL;
159	}
160
161	item = (struct distr_item *)msg_data(buf_msg(buf));
162	publ_to_item(item, publ);
163	return buf;
164}
165
166/**
167 * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
168 */
169struct sk_buff *tipc_named_withdraw(struct publication *publ)
170{
171	struct sk_buff *buf;
172	struct distr_item *item;
173
174	list_del(&publ->local_list);
175	publ_lists[publ->scope]->size--;
176
177	if (publ->scope == TIPC_NODE_SCOPE)
178		return NULL;
179
180	buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
181	if (!buf) {
182		pr_warn("Withdrawal distribution failure\n");
183		return NULL;
184	}
185
186	item = (struct distr_item *)msg_data(buf_msg(buf));
187	publ_to_item(item, publ);
188	return buf;
189}
190
191/**
192 * named_distribute - prepare name info for bulk distribution to another node
193 * @msg_list: list of messages (buffers) to be returned from this function
194 * @dnode: node to be updated
195 * @pls: linked list of publication items to be packed into buffer chain
196 */
197static void named_distribute(struct list_head *msg_list, u32 dnode,
198			     struct publ_list *pls)
199{
200	struct publication *publ;
201	struct sk_buff *buf = NULL;
202	struct distr_item *item = NULL;
203	uint dsz = pls->size * ITEM_SIZE;
204	uint msg_dsz = (tipc_node_get_mtu(dnode, 0) / ITEM_SIZE) * ITEM_SIZE;
205	uint rem = dsz;
206	uint msg_rem = 0;
207
208	list_for_each_entry(publ, &pls->list, local_list) {
209		/* Prepare next buffer: */
210		if (!buf) {
211			msg_rem = min_t(uint, rem, msg_dsz);
212			rem -= msg_rem;
213			buf = named_prepare_buf(PUBLICATION, msg_rem, dnode);
214			if (!buf) {
215				pr_warn("Bulk publication failure\n");
216				return;
217			}
218			item = (struct distr_item *)msg_data(buf_msg(buf));
219		}
220
221		/* Pack publication into message: */
222		publ_to_item(item, publ);
223		item++;
224		msg_rem -= ITEM_SIZE;
225
226		/* Append full buffer to list: */
227		if (!msg_rem) {
228			list_add_tail((struct list_head *)buf, msg_list);
229			buf = NULL;
230		}
231	}
232}
233
234/**
235 * tipc_named_node_up - tell specified node about all publications by this node
236 */
237void tipc_named_node_up(u32 dnode)
238{
239	LIST_HEAD(msg_list);
240	struct sk_buff *buf_chain;
241
242	read_lock_bh(&tipc_nametbl_lock);
243	named_distribute(&msg_list, dnode, &publ_cluster);
244	named_distribute(&msg_list, dnode, &publ_zone);
245	read_unlock_bh(&tipc_nametbl_lock);
246
247	/* Convert circular list to linear list and send: */
248	buf_chain = (struct sk_buff *)msg_list.next;
249	((struct sk_buff *)msg_list.prev)->next = NULL;
250	tipc_link_xmit(buf_chain, dnode, dnode);
251}
252
253/**
254 * named_purge_publ - remove publication associated with a failed node
255 *
256 * Invoked for each publication issued by a newly failed node.
257 * Removes publication structure from name table & deletes it.
258 */
259static void named_purge_publ(struct publication *publ)
260{
261	struct publication *p;
262
263	write_lock_bh(&tipc_nametbl_lock);
264	p = tipc_nametbl_remove_publ(publ->type, publ->lower,
265				     publ->node, publ->ref, publ->key);
266	if (p)
267		tipc_nodesub_unsubscribe(&p->subscr);
268	write_unlock_bh(&tipc_nametbl_lock);
269
270	if (p != publ) {
271		pr_err("Unable to remove publication from failed node\n"
272		       " (type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
273		       publ->type, publ->lower, publ->node, publ->ref,
274		       publ->key);
275	}
276
277	kfree(p);
278}
279
280/**
281 * tipc_update_nametbl - try to process a nametable update and notify
282 *			 subscribers
283 *
284 * tipc_nametbl_lock must be held.
285 * Returns the publication item if successful, otherwise NULL.
286 */
287static bool tipc_update_nametbl(struct distr_item *i, u32 node, u32 dtype)
288{
289	struct publication *publ = NULL;
290
291	if (dtype == PUBLICATION) {
292		publ = tipc_nametbl_insert_publ(ntohl(i->type), ntohl(i->lower),
293						ntohl(i->upper),
294						TIPC_CLUSTER_SCOPE, node,
295						ntohl(i->ref), ntohl(i->key));
296		if (publ) {
297			tipc_nodesub_subscribe(&publ->subscr, node, publ,
298					       (net_ev_handler)
299					       named_purge_publ);
300			return true;
301		}
302	} else if (dtype == WITHDRAWAL) {
303		publ = tipc_nametbl_remove_publ(ntohl(i->type), ntohl(i->lower),
304						node, ntohl(i->ref),
305						ntohl(i->key));
306		if (publ) {
307			tipc_nodesub_unsubscribe(&publ->subscr);
308			kfree(publ);
309			return true;
310		}
311	} else {
312		pr_warn("Unrecognized name table message received\n");
313	}
314	return false;
315}
316
317/**
318 * tipc_named_add_backlog - add a failed name table update to the backlog
319 *
320 */
321static void tipc_named_add_backlog(struct distr_item *i, u32 type, u32 node)
322{
323	struct distr_queue_item *e;
324	unsigned long now = get_jiffies_64();
325
326	e = kzalloc(sizeof(*e), GFP_ATOMIC);
327	if (!e)
328		return;
329	e->dtype = type;
330	e->node = node;
331	e->expires = now + msecs_to_jiffies(sysctl_tipc_named_timeout);
332	memcpy(e, i, sizeof(*i));
333	list_add_tail(&e->next, &tipc_dist_queue);
334}
335
336/**
337 * tipc_named_process_backlog - try to process any pending name table updates
338 * from the network.
339 */
340void tipc_named_process_backlog(void)
341{
342	struct distr_queue_item *e, *tmp;
343	char addr[16];
344	unsigned long now = get_jiffies_64();
345
346	list_for_each_entry_safe(e, tmp, &tipc_dist_queue, next) {
347		if (time_after(e->expires, now)) {
348			if (!tipc_update_nametbl(&e->i, e->node, e->dtype))
349				continue;
350		} else {
351			tipc_addr_string_fill(addr, e->node);
352			pr_warn_ratelimited("Dropping name table update (%d) of {%u, %u, %u} from %s key=%u\n",
353					    e->dtype, ntohl(e->i.type),
354					    ntohl(e->i.lower),
355					    ntohl(e->i.upper),
356					    addr, ntohl(e->i.key));
357		}
358		list_del(&e->next);
359		kfree(e);
360	}
361}
362
363/**
364 * tipc_named_rcv - process name table update message sent by another node
365 */
366void tipc_named_rcv(struct sk_buff *buf)
367{
368	struct tipc_msg *msg = buf_msg(buf);
369	struct distr_item *item = (struct distr_item *)msg_data(msg);
370	u32 count = msg_data_sz(msg) / ITEM_SIZE;
371	u32 node = msg_orignode(msg);
372
373	write_lock_bh(&tipc_nametbl_lock);
374	while (count--) {
375		if (!tipc_update_nametbl(item, node, msg_type(msg)))
376			tipc_named_add_backlog(item, msg_type(msg), node);
377		item++;
378	}
379	tipc_named_process_backlog();
380	write_unlock_bh(&tipc_nametbl_lock);
381	kfree_skb(buf);
382}
383
384/**
385 * tipc_named_reinit - re-initialize local publications
386 *
387 * This routine is called whenever TIPC networking is enabled.
388 * All name table entries published by this node are updated to reflect
389 * the node's new network address.
390 */
391void tipc_named_reinit(void)
392{
393	struct publication *publ;
394	int scope;
395
396	write_lock_bh(&tipc_nametbl_lock);
397
398	for (scope = TIPC_ZONE_SCOPE; scope <= TIPC_NODE_SCOPE; scope++)
399		list_for_each_entry(publ, &publ_lists[scope]->list, local_list)
400			publ->node = tipc_own_addr;
401
402	write_unlock_bh(&tipc_nametbl_lock);
403}
404