1/*
2 * net/tipc/name_distr.c: TIPC name distribution code
3 *
4 * Copyright (c) 2000-2006, 2014-2019, Ericsson AB
5 * Copyright (c) 2005, 2010-2011, Wind River Systems
6 * Copyright (c) 2020-2021, Red Hat Inc
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the names of the copyright holders nor the names of its
18 *    contributors may be used to endorse or promote products derived from
19 *    this software without specific prior written permission.
20 *
21 * Alternatively, this software may be distributed under the terms of the
22 * GNU General Public License ("GPL") version 2 as published by the Free
23 * Software Foundation.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
26 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
29 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38#include "core.h"
39#include "link.h"
40#include "name_distr.h"
41
42int sysctl_tipc_named_timeout __read_mostly = 2000;
43
44/**
45 * publ_to_item - add publication info to a publication message
46 * @p: publication info
47 * @i: location of item in the message
48 */
49static void publ_to_item(struct distr_item *i, struct publication *p)
50{
51	i->type = htonl(p->sr.type);
52	i->lower = htonl(p->sr.lower);
53	i->upper = htonl(p->sr.upper);
54	i->port = htonl(p->sk.ref);
55	i->key = htonl(p->key);
56}
57
58/**
59 * named_prepare_buf - allocate & initialize a publication message
60 * @net: the associated network namespace
61 * @type: message type
62 * @size: payload size
63 * @dest: destination node
64 *
65 * The buffer returned is of size INT_H_SIZE + payload size
66 */
67static struct sk_buff *named_prepare_buf(struct net *net, u32 type, u32 size,
68					 u32 dest)
69{
70	struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size, GFP_ATOMIC);
71	u32 self = tipc_own_addr(net);
72	struct tipc_msg *msg;
73
74	if (buf != NULL) {
75		msg = buf_msg(buf);
76		tipc_msg_init(self, msg, NAME_DISTRIBUTOR,
77			      type, INT_H_SIZE, dest);
78		msg_set_size(msg, INT_H_SIZE + size);
79	}
80	return buf;
81}
82
83/**
84 * tipc_named_publish - tell other nodes about a new publication by this node
85 * @net: the associated network namespace
86 * @p: the new publication
87 */
88struct sk_buff *tipc_named_publish(struct net *net, struct publication *p)
89{
90	struct name_table *nt = tipc_name_table(net);
91	struct distr_item *item;
92	struct sk_buff *skb;
93
94	if (p->scope == TIPC_NODE_SCOPE) {
95		list_add_tail_rcu(&p->binding_node, &nt->node_scope);
96		return NULL;
97	}
98	write_lock_bh(&nt->cluster_scope_lock);
99	list_add_tail(&p->binding_node, &nt->cluster_scope);
100	write_unlock_bh(&nt->cluster_scope_lock);
101	skb = named_prepare_buf(net, PUBLICATION, ITEM_SIZE, 0);
102	if (!skb) {
103		pr_warn("Publication distribution failure\n");
104		return NULL;
105	}
106	msg_set_named_seqno(buf_msg(skb), nt->snd_nxt++);
107	msg_set_non_legacy(buf_msg(skb));
108	item = (struct distr_item *)msg_data(buf_msg(skb));
109	publ_to_item(item, p);
110	return skb;
111}
112
113/**
114 * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
115 * @net: the associated network namespace
116 * @p: the withdrawn publication
117 */
118struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *p)
119{
120	struct name_table *nt = tipc_name_table(net);
121	struct distr_item *item;
122	struct sk_buff *skb;
123
124	write_lock_bh(&nt->cluster_scope_lock);
125	list_del(&p->binding_node);
126	write_unlock_bh(&nt->cluster_scope_lock);
127	if (p->scope == TIPC_NODE_SCOPE)
128		return NULL;
129
130	skb = named_prepare_buf(net, WITHDRAWAL, ITEM_SIZE, 0);
131	if (!skb) {
132		pr_warn("Withdrawal distribution failure\n");
133		return NULL;
134	}
135	msg_set_named_seqno(buf_msg(skb), nt->snd_nxt++);
136	msg_set_non_legacy(buf_msg(skb));
137	item = (struct distr_item *)msg_data(buf_msg(skb));
138	publ_to_item(item, p);
139	return skb;
140}
141
142/**
143 * named_distribute - prepare name info for bulk distribution to another node
144 * @net: the associated network namespace
145 * @list: list of messages (buffers) to be returned from this function
146 * @dnode: node to be updated
147 * @pls: linked list of publication items to be packed into buffer chain
148 * @seqno: sequence number for this message
149 */
150static void named_distribute(struct net *net, struct sk_buff_head *list,
151			     u32 dnode, struct list_head *pls, u16 seqno)
152{
153	struct publication *publ;
154	struct sk_buff *skb = NULL;
155	struct distr_item *item = NULL;
156	u32 msg_dsz = ((tipc_node_get_mtu(net, dnode, 0, false) - INT_H_SIZE) /
157			ITEM_SIZE) * ITEM_SIZE;
158	u32 msg_rem = msg_dsz;
159	struct tipc_msg *hdr;
160
161	list_for_each_entry(publ, pls, binding_node) {
162		/* Prepare next buffer: */
163		if (!skb) {
164			skb = named_prepare_buf(net, PUBLICATION, msg_rem,
165						dnode);
166			if (!skb) {
167				pr_warn("Bulk publication failure\n");
168				return;
169			}
170			hdr = buf_msg(skb);
171			msg_set_bc_ack_invalid(hdr, true);
172			msg_set_bulk(hdr);
173			msg_set_non_legacy(hdr);
174			item = (struct distr_item *)msg_data(hdr);
175		}
176
177		/* Pack publication into message: */
178		publ_to_item(item, publ);
179		item++;
180		msg_rem -= ITEM_SIZE;
181
182		/* Append full buffer to list: */
183		if (!msg_rem) {
184			__skb_queue_tail(list, skb);
185			skb = NULL;
186			msg_rem = msg_dsz;
187		}
188	}
189	if (skb) {
190		hdr = buf_msg(skb);
191		msg_set_size(hdr, INT_H_SIZE + (msg_dsz - msg_rem));
192		skb_trim(skb, INT_H_SIZE + (msg_dsz - msg_rem));
193		__skb_queue_tail(list, skb);
194	}
195	hdr = buf_msg(skb_peek_tail(list));
196	msg_set_last_bulk(hdr);
197	msg_set_named_seqno(hdr, seqno);
198}
199
200/**
201 * tipc_named_node_up - tell specified node about all publications by this node
202 * @net: the associated network namespace
203 * @dnode: destination node
204 * @capabilities: peer node's capabilities
205 */
206void tipc_named_node_up(struct net *net, u32 dnode, u16 capabilities)
207{
208	struct name_table *nt = tipc_name_table(net);
209	struct tipc_net *tn = tipc_net(net);
210	struct sk_buff_head head;
211	u16 seqno;
212
213	__skb_queue_head_init(&head);
214	spin_lock_bh(&tn->nametbl_lock);
215	if (!(capabilities & TIPC_NAMED_BCAST))
216		nt->rc_dests++;
217	seqno = nt->snd_nxt;
218	spin_unlock_bh(&tn->nametbl_lock);
219
220	read_lock_bh(&nt->cluster_scope_lock);
221	named_distribute(net, &head, dnode, &nt->cluster_scope, seqno);
222	tipc_node_xmit(net, &head, dnode, 0);
223	read_unlock_bh(&nt->cluster_scope_lock);
224}
225
226/**
227 * tipc_publ_purge - remove publication associated with a failed node
228 * @net: the associated network namespace
229 * @p: the publication to remove
230 * @addr: failed node's address
231 *
232 * Invoked for each publication issued by a newly failed node.
233 * Removes publication structure from name table & deletes it.
234 */
235static void tipc_publ_purge(struct net *net, struct publication *p, u32 addr)
236{
237	struct tipc_net *tn = tipc_net(net);
238	struct publication *_p;
239	struct tipc_uaddr ua;
240
241	tipc_uaddr(&ua, TIPC_SERVICE_RANGE, p->scope, p->sr.type,
242		   p->sr.lower, p->sr.upper);
243	spin_lock_bh(&tn->nametbl_lock);
244	_p = tipc_nametbl_remove_publ(net, &ua, &p->sk, p->key);
245	if (_p)
246		tipc_node_unsubscribe(net, &_p->binding_node, addr);
247	spin_unlock_bh(&tn->nametbl_lock);
248	if (_p)
249		kfree_rcu(_p, rcu);
250}
251
252void tipc_publ_notify(struct net *net, struct list_head *nsub_list,
253		      u32 addr, u16 capabilities)
254{
255	struct name_table *nt = tipc_name_table(net);
256	struct tipc_net *tn = tipc_net(net);
257
258	struct publication *publ, *tmp;
259
260	list_for_each_entry_safe(publ, tmp, nsub_list, binding_node)
261		tipc_publ_purge(net, publ, addr);
262	spin_lock_bh(&tn->nametbl_lock);
263	if (!(capabilities & TIPC_NAMED_BCAST))
264		nt->rc_dests--;
265	spin_unlock_bh(&tn->nametbl_lock);
266}
267
268/**
269 * tipc_update_nametbl - try to process a nametable update and notify
270 *			 subscribers
271 * @net: the associated network namespace
272 * @i: location of item in the message
273 * @node: node address
274 * @dtype: name distributor message type
275 *
276 * tipc_nametbl_lock must be held.
277 * Return: the publication item if successful, otherwise NULL.
278 */
279static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
280				u32 node, u32 dtype)
281{
282	struct publication *p = NULL;
283	struct tipc_socket_addr sk;
284	struct tipc_uaddr ua;
285	u32 key = ntohl(i->key);
286
287	tipc_uaddr(&ua, TIPC_SERVICE_RANGE, TIPC_CLUSTER_SCOPE,
288		   ntohl(i->type), ntohl(i->lower), ntohl(i->upper));
289	sk.ref = ntohl(i->port);
290	sk.node = node;
291
292	if (dtype == PUBLICATION) {
293		p = tipc_nametbl_insert_publ(net, &ua, &sk, key);
294		if (p) {
295			tipc_node_subscribe(net, &p->binding_node, node);
296			return true;
297		}
298	} else if (dtype == WITHDRAWAL) {
299		p = tipc_nametbl_remove_publ(net, &ua, &sk, key);
300		if (p) {
301			tipc_node_unsubscribe(net, &p->binding_node, node);
302			kfree_rcu(p, rcu);
303			return true;
304		}
305		pr_warn_ratelimited("Failed to remove binding %u,%u from %u\n",
306				    ua.sr.type, ua.sr.lower, node);
307	} else {
308		pr_warn_ratelimited("Unknown name table message received\n");
309	}
310	return false;
311}
312
313static struct sk_buff *tipc_named_dequeue(struct sk_buff_head *namedq,
314					  u16 *rcv_nxt, bool *open)
315{
316	struct sk_buff *skb, *tmp;
317	struct tipc_msg *hdr;
318	u16 seqno;
319
320	spin_lock_bh(&namedq->lock);
321	skb_queue_walk_safe(namedq, skb, tmp) {
322		if (unlikely(skb_linearize(skb))) {
323			__skb_unlink(skb, namedq);
324			kfree_skb(skb);
325			continue;
326		}
327		hdr = buf_msg(skb);
328		seqno = msg_named_seqno(hdr);
329		if (msg_is_last_bulk(hdr)) {
330			*rcv_nxt = seqno;
331			*open = true;
332		}
333
334		if (msg_is_bulk(hdr) || msg_is_legacy(hdr)) {
335			__skb_unlink(skb, namedq);
336			spin_unlock_bh(&namedq->lock);
337			return skb;
338		}
339
340		if (*open && (*rcv_nxt == seqno)) {
341			(*rcv_nxt)++;
342			__skb_unlink(skb, namedq);
343			spin_unlock_bh(&namedq->lock);
344			return skb;
345		}
346
347		if (less(seqno, *rcv_nxt)) {
348			__skb_unlink(skb, namedq);
349			kfree_skb(skb);
350			continue;
351		}
352	}
353	spin_unlock_bh(&namedq->lock);
354	return NULL;
355}
356
357/**
358 * tipc_named_rcv - process name table update messages sent by another node
359 * @net: the associated network namespace
360 * @namedq: queue to receive from
361 * @rcv_nxt: store last received seqno here
362 * @open: last bulk msg was received (FIXME)
363 */
364void tipc_named_rcv(struct net *net, struct sk_buff_head *namedq,
365		    u16 *rcv_nxt, bool *open)
366{
367	struct tipc_net *tn = tipc_net(net);
368	struct distr_item *item;
369	struct tipc_msg *hdr;
370	struct sk_buff *skb;
371	u32 count, node;
372
373	spin_lock_bh(&tn->nametbl_lock);
374	while ((skb = tipc_named_dequeue(namedq, rcv_nxt, open))) {
375		hdr = buf_msg(skb);
376		node = msg_orignode(hdr);
377		item = (struct distr_item *)msg_data(hdr);
378		count = msg_data_sz(hdr) / ITEM_SIZE;
379		while (count--) {
380			tipc_update_nametbl(net, item, node, msg_type(hdr));
381			item++;
382		}
383		kfree_skb(skb);
384	}
385	spin_unlock_bh(&tn->nametbl_lock);
386}
387
388/**
389 * tipc_named_reinit - re-initialize local publications
390 * @net: the associated network namespace
391 *
392 * This routine is called whenever TIPC networking is enabled.
393 * All name table entries published by this node are updated to reflect
394 * the node's new network address.
395 */
396void tipc_named_reinit(struct net *net)
397{
398	struct name_table *nt = tipc_name_table(net);
399	struct tipc_net *tn = tipc_net(net);
400	struct publication *p;
401	u32 self = tipc_own_addr(net);
402
403	spin_lock_bh(&tn->nametbl_lock);
404
405	list_for_each_entry_rcu(p, &nt->node_scope, binding_node)
406		p->sk.node = self;
407	list_for_each_entry_rcu(p, &nt->cluster_scope, binding_node)
408		p->sk.node = self;
409	nt->rc_dests = 0;
410	spin_unlock_bh(&tn->nametbl_lock);
411}
412