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
41int sysctl_tipc_named_timeout __read_mostly = 2000;
42
43/**
44 * struct tipc_dist_queue - queue holding deferred name table updates
45 */
46static struct list_head tipc_dist_queue = LIST_HEAD_INIT(tipc_dist_queue);
47
48struct distr_queue_item {
49	struct distr_item i;
50	u32 dtype;
51	u32 node;
52	unsigned long expires;
53	struct list_head next;
54};
55
56/**
57 * publ_to_item - add publication info to a publication message
58 */
59static void publ_to_item(struct distr_item *i, struct publication *p)
60{
61	i->type = htonl(p->type);
62	i->lower = htonl(p->lower);
63	i->upper = htonl(p->upper);
64	i->ref = htonl(p->ref);
65	i->key = htonl(p->key);
66}
67
68/**
69 * named_prepare_buf - allocate & initialize a publication message
70 */
71static struct sk_buff *named_prepare_buf(struct net *net, u32 type, u32 size,
72					 u32 dest)
73{
74	struct tipc_net *tn = net_generic(net, tipc_net_id);
75	struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size);
76	struct tipc_msg *msg;
77
78	if (buf != NULL) {
79		msg = buf_msg(buf);
80		tipc_msg_init(tn->own_addr, msg, NAME_DISTRIBUTOR, type,
81			      INT_H_SIZE, dest);
82		msg_set_size(msg, INT_H_SIZE + size);
83	}
84	return buf;
85}
86
87void named_cluster_distribute(struct net *net, struct sk_buff *skb)
88{
89	struct tipc_net *tn = net_generic(net, tipc_net_id);
90	struct sk_buff *oskb;
91	struct tipc_node *node;
92	u32 dnode;
93
94	rcu_read_lock();
95	list_for_each_entry_rcu(node, &tn->node_list, list) {
96		dnode = node->addr;
97		if (in_own_node(net, dnode))
98			continue;
99		if (!tipc_node_is_up(node))
100			continue;
101		oskb = pskb_copy(skb, GFP_ATOMIC);
102		if (!oskb)
103			break;
104		msg_set_destnode(buf_msg(oskb), dnode);
105		tipc_node_xmit_skb(net, oskb, dnode, 0);
106	}
107	rcu_read_unlock();
108
109	kfree_skb(skb);
110}
111
112/**
113 * tipc_named_publish - tell other nodes about a new publication by this node
114 */
115struct sk_buff *tipc_named_publish(struct net *net, struct publication *publ)
116{
117	struct tipc_net *tn = net_generic(net, tipc_net_id);
118	struct sk_buff *buf;
119	struct distr_item *item;
120
121	list_add_tail_rcu(&publ->local_list,
122			  &tn->nametbl->publ_list[publ->scope]);
123
124	if (publ->scope == TIPC_NODE_SCOPE)
125		return NULL;
126
127	buf = named_prepare_buf(net, PUBLICATION, ITEM_SIZE, 0);
128	if (!buf) {
129		pr_warn("Publication distribution failure\n");
130		return NULL;
131	}
132
133	item = (struct distr_item *)msg_data(buf_msg(buf));
134	publ_to_item(item, publ);
135	return buf;
136}
137
138/**
139 * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
140 */
141struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ)
142{
143	struct sk_buff *buf;
144	struct distr_item *item;
145
146	list_del(&publ->local_list);
147
148	if (publ->scope == TIPC_NODE_SCOPE)
149		return NULL;
150
151	buf = named_prepare_buf(net, WITHDRAWAL, ITEM_SIZE, 0);
152	if (!buf) {
153		pr_warn("Withdrawal distribution failure\n");
154		return NULL;
155	}
156
157	item = (struct distr_item *)msg_data(buf_msg(buf));
158	publ_to_item(item, publ);
159	return buf;
160}
161
162/**
163 * named_distribute - prepare name info for bulk distribution to another node
164 * @list: list of messages (buffers) to be returned from this function
165 * @dnode: node to be updated
166 * @pls: linked list of publication items to be packed into buffer chain
167 */
168static void named_distribute(struct net *net, struct sk_buff_head *list,
169			     u32 dnode, struct list_head *pls)
170{
171	struct publication *publ;
172	struct sk_buff *skb = NULL;
173	struct distr_item *item = NULL;
174	uint msg_dsz = (tipc_node_get_mtu(net, dnode, 0) / ITEM_SIZE) *
175			ITEM_SIZE;
176	uint msg_rem = msg_dsz;
177
178	list_for_each_entry(publ, pls, local_list) {
179		/* Prepare next buffer: */
180		if (!skb) {
181			skb = named_prepare_buf(net, PUBLICATION, msg_rem,
182						dnode);
183			if (!skb) {
184				pr_warn("Bulk publication failure\n");
185				return;
186			}
187			item = (struct distr_item *)msg_data(buf_msg(skb));
188		}
189
190		/* Pack publication into message: */
191		publ_to_item(item, publ);
192		item++;
193		msg_rem -= ITEM_SIZE;
194
195		/* Append full buffer to list: */
196		if (!msg_rem) {
197			__skb_queue_tail(list, skb);
198			skb = NULL;
199			msg_rem = msg_dsz;
200		}
201	}
202	if (skb) {
203		msg_set_size(buf_msg(skb), INT_H_SIZE + (msg_dsz - msg_rem));
204		skb_trim(skb, INT_H_SIZE + (msg_dsz - msg_rem));
205		__skb_queue_tail(list, skb);
206	}
207}
208
209/**
210 * tipc_named_node_up - tell specified node about all publications by this node
211 */
212void tipc_named_node_up(struct net *net, u32 dnode)
213{
214	struct tipc_net *tn = net_generic(net, tipc_net_id);
215	struct sk_buff_head head;
216
217	__skb_queue_head_init(&head);
218
219	rcu_read_lock();
220	named_distribute(net, &head, dnode,
221			 &tn->nametbl->publ_list[TIPC_CLUSTER_SCOPE]);
222	named_distribute(net, &head, dnode,
223			 &tn->nametbl->publ_list[TIPC_ZONE_SCOPE]);
224	rcu_read_unlock();
225
226	tipc_node_xmit(net, &head, dnode, 0);
227}
228
229static void tipc_publ_subscribe(struct net *net, struct publication *publ,
230				u32 addr)
231{
232	struct tipc_node *node;
233
234	if (in_own_node(net, addr))
235		return;
236
237	node = tipc_node_find(net, addr);
238	if (!node) {
239		pr_warn("Node subscription rejected, unknown node 0x%x\n",
240			addr);
241		return;
242	}
243
244	tipc_node_lock(node);
245	list_add_tail(&publ->nodesub_list, &node->publ_list);
246	tipc_node_unlock(node);
247	tipc_node_put(node);
248}
249
250static void tipc_publ_unsubscribe(struct net *net, struct publication *publ,
251				  u32 addr)
252{
253	struct tipc_node *node;
254
255	node = tipc_node_find(net, addr);
256	if (!node)
257		return;
258
259	tipc_node_lock(node);
260	list_del_init(&publ->nodesub_list);
261	tipc_node_unlock(node);
262	tipc_node_put(node);
263}
264
265/**
266 * tipc_publ_purge - remove publication associated with a failed node
267 *
268 * Invoked for each publication issued by a newly failed node.
269 * Removes publication structure from name table & deletes it.
270 */
271static void tipc_publ_purge(struct net *net, struct publication *publ, u32 addr)
272{
273	struct tipc_net *tn = net_generic(net, tipc_net_id);
274	struct publication *p;
275
276	spin_lock_bh(&tn->nametbl_lock);
277	p = tipc_nametbl_remove_publ(net, publ->type, publ->lower,
278				     publ->node, publ->ref, publ->key);
279	if (p)
280		tipc_publ_unsubscribe(net, p, addr);
281	spin_unlock_bh(&tn->nametbl_lock);
282
283	if (p != publ) {
284		pr_err("Unable to remove publication from failed node\n"
285		       " (type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
286		       publ->type, publ->lower, publ->node, publ->ref,
287		       publ->key);
288	}
289
290	kfree_rcu(p, rcu);
291}
292
293void tipc_publ_notify(struct net *net, struct list_head *nsub_list, u32 addr)
294{
295	struct publication *publ, *tmp;
296
297	list_for_each_entry_safe(publ, tmp, nsub_list, nodesub_list)
298		tipc_publ_purge(net, publ, addr);
299}
300
301/**
302 * tipc_update_nametbl - try to process a nametable update and notify
303 *			 subscribers
304 *
305 * tipc_nametbl_lock must be held.
306 * Returns the publication item if successful, otherwise NULL.
307 */
308static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
309				u32 node, u32 dtype)
310{
311	struct publication *publ = NULL;
312
313	if (dtype == PUBLICATION) {
314		publ = tipc_nametbl_insert_publ(net, ntohl(i->type),
315						ntohl(i->lower),
316						ntohl(i->upper),
317						TIPC_CLUSTER_SCOPE, node,
318						ntohl(i->ref), ntohl(i->key));
319		if (publ) {
320			tipc_publ_subscribe(net, publ, node);
321			return true;
322		}
323	} else if (dtype == WITHDRAWAL) {
324		publ = tipc_nametbl_remove_publ(net, ntohl(i->type),
325						ntohl(i->lower),
326						node, ntohl(i->ref),
327						ntohl(i->key));
328		if (publ) {
329			tipc_publ_unsubscribe(net, publ, node);
330			kfree_rcu(publ, rcu);
331			return true;
332		}
333	} else {
334		pr_warn("Unrecognized name table message received\n");
335	}
336	return false;
337}
338
339/**
340 * tipc_named_add_backlog - add a failed name table update to the backlog
341 *
342 */
343static void tipc_named_add_backlog(struct distr_item *i, u32 type, u32 node)
344{
345	struct distr_queue_item *e;
346	unsigned long now = get_jiffies_64();
347
348	e = kzalloc(sizeof(*e), GFP_ATOMIC);
349	if (!e)
350		return;
351	e->dtype = type;
352	e->node = node;
353	e->expires = now + msecs_to_jiffies(sysctl_tipc_named_timeout);
354	memcpy(e, i, sizeof(*i));
355	list_add_tail(&e->next, &tipc_dist_queue);
356}
357
358/**
359 * tipc_named_process_backlog - try to process any pending name table updates
360 * from the network.
361 */
362void tipc_named_process_backlog(struct net *net)
363{
364	struct distr_queue_item *e, *tmp;
365	char addr[16];
366	unsigned long now = get_jiffies_64();
367
368	list_for_each_entry_safe(e, tmp, &tipc_dist_queue, next) {
369		if (time_after(e->expires, now)) {
370			if (!tipc_update_nametbl(net, &e->i, e->node, e->dtype))
371				continue;
372		} else {
373			tipc_addr_string_fill(addr, e->node);
374			pr_warn_ratelimited("Dropping name table update (%d) of {%u, %u, %u} from %s key=%u\n",
375					    e->dtype, ntohl(e->i.type),
376					    ntohl(e->i.lower),
377					    ntohl(e->i.upper),
378					    addr, ntohl(e->i.key));
379		}
380		list_del(&e->next);
381		kfree(e);
382	}
383}
384
385/**
386 * tipc_named_rcv - process name table update messages sent by another node
387 */
388void tipc_named_rcv(struct net *net, struct sk_buff_head *inputq)
389{
390	struct tipc_net *tn = net_generic(net, tipc_net_id);
391	struct tipc_msg *msg;
392	struct distr_item *item;
393	uint count;
394	u32 node;
395	struct sk_buff *skb;
396	int mtype;
397
398	spin_lock_bh(&tn->nametbl_lock);
399	for (skb = skb_dequeue(inputq); skb; skb = skb_dequeue(inputq)) {
400		msg = buf_msg(skb);
401		mtype = msg_type(msg);
402		item = (struct distr_item *)msg_data(msg);
403		count = msg_data_sz(msg) / ITEM_SIZE;
404		node = msg_orignode(msg);
405		while (count--) {
406			if (!tipc_update_nametbl(net, item, node, mtype))
407				tipc_named_add_backlog(item, mtype, node);
408			item++;
409		}
410		kfree_skb(skb);
411		tipc_named_process_backlog(net);
412	}
413	spin_unlock_bh(&tn->nametbl_lock);
414}
415
416/**
417 * tipc_named_reinit - re-initialize local publications
418 *
419 * This routine is called whenever TIPC networking is enabled.
420 * All name table entries published by this node are updated to reflect
421 * the node's new network address.
422 */
423void tipc_named_reinit(struct net *net)
424{
425	struct tipc_net *tn = net_generic(net, tipc_net_id);
426	struct publication *publ;
427	int scope;
428
429	spin_lock_bh(&tn->nametbl_lock);
430
431	for (scope = TIPC_ZONE_SCOPE; scope <= TIPC_NODE_SCOPE; scope++)
432		list_for_each_entry_rcu(publ, &tn->nametbl->publ_list[scope],
433					local_list)
434			publ->node = tn->own_addr;
435
436	spin_unlock_bh(&tn->nametbl_lock);
437}
438