xref: /linux/net/tipc/node.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5) 
1 /*
2  * net/tipc/node.c: TIPC node management routines
3  *
4  * Copyright (c) 2000-2006, 2012-2014, Ericsson AB
5  * Copyright (c) 2005-2006, 2010-2014, 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 "config.h"
39 #include "node.h"
40 #include "name_distr.h"
41 
42 #define NODE_HTABLE_SIZE 512
43 
44 static void node_lost_contact(struct tipc_node *n_ptr);
45 static void node_established_contact(struct tipc_node *n_ptr);
46 
47 static struct hlist_head node_htable[NODE_HTABLE_SIZE];
48 LIST_HEAD(tipc_node_list);
49 static u32 tipc_num_nodes;
50 static u32 tipc_num_links;
51 static DEFINE_SPINLOCK(node_list_lock);
52 
53 /*
54  * A trivial power-of-two bitmask technique is used for speed, since this
55  * operation is done for every incoming TIPC packet. The number of hash table
56  * entries has been chosen so that no hash chain exceeds 8 nodes and will
57  * usually be much smaller (typically only a single node).
58  */
59 static unsigned int tipc_hashfn(u32 addr)
60 {
61 	return addr & (NODE_HTABLE_SIZE - 1);
62 }
63 
64 /*
65  * tipc_node_find - locate specified node object, if it exists
66  */
67 struct tipc_node *tipc_node_find(u32 addr)
68 {
69 	struct tipc_node *node;
70 
71 	if (unlikely(!in_own_cluster_exact(addr)))
72 		return NULL;
73 
74 	rcu_read_lock();
75 	hlist_for_each_entry_rcu(node, &node_htable[tipc_hashfn(addr)], hash) {
76 		if (node->addr == addr) {
77 			rcu_read_unlock();
78 			return node;
79 		}
80 	}
81 	rcu_read_unlock();
82 	return NULL;
83 }
84 
85 struct tipc_node *tipc_node_create(u32 addr)
86 {
87 	struct tipc_node *n_ptr, *temp_node;
88 
89 	spin_lock_bh(&node_list_lock);
90 
91 	n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
92 	if (!n_ptr) {
93 		spin_unlock_bh(&node_list_lock);
94 		pr_warn("Node creation failed, no memory\n");
95 		return NULL;
96 	}
97 
98 	n_ptr->addr = addr;
99 	spin_lock_init(&n_ptr->lock);
100 	INIT_HLIST_NODE(&n_ptr->hash);
101 	INIT_LIST_HEAD(&n_ptr->list);
102 	INIT_LIST_HEAD(&n_ptr->nsub);
103 
104 	hlist_add_head_rcu(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
105 
106 	list_for_each_entry_rcu(temp_node, &tipc_node_list, list) {
107 		if (n_ptr->addr < temp_node->addr)
108 			break;
109 	}
110 	list_add_tail_rcu(&n_ptr->list, &temp_node->list);
111 	n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN;
112 	n_ptr->signature = INVALID_NODE_SIG;
113 
114 	tipc_num_nodes++;
115 
116 	spin_unlock_bh(&node_list_lock);
117 	return n_ptr;
118 }
119 
120 static void tipc_node_delete(struct tipc_node *n_ptr)
121 {
122 	list_del_rcu(&n_ptr->list);
123 	hlist_del_rcu(&n_ptr->hash);
124 	kfree_rcu(n_ptr, rcu);
125 
126 	tipc_num_nodes--;
127 }
128 
129 void tipc_node_stop(void)
130 {
131 	struct tipc_node *node, *t_node;
132 
133 	spin_lock_bh(&node_list_lock);
134 	list_for_each_entry_safe(node, t_node, &tipc_node_list, list)
135 		tipc_node_delete(node);
136 	spin_unlock_bh(&node_list_lock);
137 }
138 
139 /**
140  * tipc_node_link_up - handle addition of link
141  *
142  * Link becomes active (alone or shared) or standby, depending on its priority.
143  */
144 void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
145 {
146 	struct tipc_link **active = &n_ptr->active_links[0];
147 	u32 addr = n_ptr->addr;
148 
149 	n_ptr->working_links++;
150 	tipc_nametbl_publish(TIPC_LINK_STATE, addr, addr, TIPC_NODE_SCOPE,
151 			     l_ptr->bearer_id, addr);
152 	pr_info("Established link <%s> on network plane %c\n",
153 		l_ptr->name, l_ptr->net_plane);
154 
155 	if (!active[0]) {
156 		active[0] = active[1] = l_ptr;
157 		node_established_contact(n_ptr);
158 		goto exit;
159 	}
160 	if (l_ptr->priority < active[0]->priority) {
161 		pr_info("New link <%s> becomes standby\n", l_ptr->name);
162 		goto exit;
163 	}
164 	tipc_link_dup_queue_xmit(active[0], l_ptr);
165 	if (l_ptr->priority == active[0]->priority) {
166 		active[0] = l_ptr;
167 		goto exit;
168 	}
169 	pr_info("Old link <%s> becomes standby\n", active[0]->name);
170 	if (active[1] != active[0])
171 		pr_info("Old link <%s> becomes standby\n", active[1]->name);
172 	active[0] = active[1] = l_ptr;
173 exit:
174 	/* Leave room for changeover header when returning 'mtu' to users: */
175 	n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
176 	n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
177 }
178 
179 /**
180  * node_select_active_links - select active link
181  */
182 static void node_select_active_links(struct tipc_node *n_ptr)
183 {
184 	struct tipc_link **active = &n_ptr->active_links[0];
185 	u32 i;
186 	u32 highest_prio = 0;
187 
188 	active[0] = active[1] = NULL;
189 
190 	for (i = 0; i < MAX_BEARERS; i++) {
191 		struct tipc_link *l_ptr = n_ptr->links[i];
192 
193 		if (!l_ptr || !tipc_link_is_up(l_ptr) ||
194 		    (l_ptr->priority < highest_prio))
195 			continue;
196 
197 		if (l_ptr->priority > highest_prio) {
198 			highest_prio = l_ptr->priority;
199 			active[0] = active[1] = l_ptr;
200 		} else {
201 			active[1] = l_ptr;
202 		}
203 	}
204 }
205 
206 /**
207  * tipc_node_link_down - handle loss of link
208  */
209 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
210 {
211 	struct tipc_link **active;
212 	u32 addr = n_ptr->addr;
213 
214 	n_ptr->working_links--;
215 	tipc_nametbl_withdraw(TIPC_LINK_STATE, addr, l_ptr->bearer_id, addr);
216 
217 	if (!tipc_link_is_active(l_ptr)) {
218 		pr_info("Lost standby link <%s> on network plane %c\n",
219 			l_ptr->name, l_ptr->net_plane);
220 		return;
221 	}
222 	pr_info("Lost link <%s> on network plane %c\n",
223 		l_ptr->name, l_ptr->net_plane);
224 
225 	active = &n_ptr->active_links[0];
226 	if (active[0] == l_ptr)
227 		active[0] = active[1];
228 	if (active[1] == l_ptr)
229 		active[1] = active[0];
230 	if (active[0] == l_ptr)
231 		node_select_active_links(n_ptr);
232 	if (tipc_node_is_up(n_ptr))
233 		tipc_link_failover_send_queue(l_ptr);
234 	else
235 		node_lost_contact(n_ptr);
236 
237 	/* Leave room for changeover header when returning 'mtu' to users: */
238 	if (active[0]) {
239 		n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
240 		n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
241 		return;
242 	}
243 
244 	/* Loopback link went down? No fragmentation needed from now on. */
245 	if (n_ptr->addr == tipc_own_addr) {
246 		n_ptr->act_mtus[0] = MAX_MSG_SIZE;
247 		n_ptr->act_mtus[1] = MAX_MSG_SIZE;
248 	}
249 }
250 
251 int tipc_node_active_links(struct tipc_node *n_ptr)
252 {
253 	return n_ptr->active_links[0] != NULL;
254 }
255 
256 int tipc_node_is_up(struct tipc_node *n_ptr)
257 {
258 	return tipc_node_active_links(n_ptr);
259 }
260 
261 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
262 {
263 	n_ptr->links[l_ptr->bearer_id] = l_ptr;
264 	spin_lock_bh(&node_list_lock);
265 	tipc_num_links++;
266 	spin_unlock_bh(&node_list_lock);
267 	n_ptr->link_cnt++;
268 }
269 
270 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
271 {
272 	int i;
273 
274 	for (i = 0; i < MAX_BEARERS; i++) {
275 		if (l_ptr != n_ptr->links[i])
276 			continue;
277 		n_ptr->links[i] = NULL;
278 		spin_lock_bh(&node_list_lock);
279 		tipc_num_links--;
280 		spin_unlock_bh(&node_list_lock);
281 		n_ptr->link_cnt--;
282 	}
283 }
284 
285 static void node_established_contact(struct tipc_node *n_ptr)
286 {
287 	n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
288 	n_ptr->bclink.oos_state = 0;
289 	n_ptr->bclink.acked = tipc_bclink_get_last_sent();
290 	tipc_bclink_add_node(n_ptr->addr);
291 }
292 
293 static void node_lost_contact(struct tipc_node *n_ptr)
294 {
295 	char addr_string[16];
296 	u32 i;
297 
298 	pr_info("Lost contact with %s\n",
299 		tipc_addr_string_fill(addr_string, n_ptr->addr));
300 
301 	/* Flush broadcast link info associated with lost node */
302 	if (n_ptr->bclink.recv_permitted) {
303 		kfree_skb_list(n_ptr->bclink.deferred_head);
304 		n_ptr->bclink.deferred_size = 0;
305 
306 		if (n_ptr->bclink.reasm_buf) {
307 			kfree_skb(n_ptr->bclink.reasm_buf);
308 			n_ptr->bclink.reasm_buf = NULL;
309 		}
310 
311 		tipc_bclink_remove_node(n_ptr->addr);
312 		tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
313 
314 		n_ptr->bclink.recv_permitted = false;
315 	}
316 
317 	/* Abort link changeover */
318 	for (i = 0; i < MAX_BEARERS; i++) {
319 		struct tipc_link *l_ptr = n_ptr->links[i];
320 		if (!l_ptr)
321 			continue;
322 		l_ptr->reset_checkpoint = l_ptr->next_in_no;
323 		l_ptr->exp_msg_count = 0;
324 		tipc_link_reset_fragments(l_ptr);
325 	}
326 
327 	n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN;
328 
329 	/* Notify subscribers and prevent re-contact with node until
330 	 * cleanup is done.
331 	 */
332 	n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN |
333 			       TIPC_NOTIFY_NODE_DOWN;
334 }
335 
336 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
337 {
338 	u32 domain;
339 	struct sk_buff *buf;
340 	struct tipc_node *n_ptr;
341 	struct tipc_node_info node_info;
342 	u32 payload_size;
343 
344 	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
345 		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
346 
347 	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
348 	if (!tipc_addr_domain_valid(domain))
349 		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
350 						   " (network address)");
351 
352 	spin_lock_bh(&node_list_lock);
353 	if (!tipc_num_nodes) {
354 		spin_unlock_bh(&node_list_lock);
355 		return tipc_cfg_reply_none();
356 	}
357 
358 	/* For now, get space for all other nodes */
359 	payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
360 	if (payload_size > 32768u) {
361 		spin_unlock_bh(&node_list_lock);
362 		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
363 						   " (too many nodes)");
364 	}
365 	spin_unlock_bh(&node_list_lock);
366 
367 	buf = tipc_cfg_reply_alloc(payload_size);
368 	if (!buf)
369 		return NULL;
370 
371 	/* Add TLVs for all nodes in scope */
372 	rcu_read_lock();
373 	list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
374 		if (!tipc_in_scope(domain, n_ptr->addr))
375 			continue;
376 		node_info.addr = htonl(n_ptr->addr);
377 		node_info.up = htonl(tipc_node_is_up(n_ptr));
378 		tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
379 				    &node_info, sizeof(node_info));
380 	}
381 	rcu_read_unlock();
382 	return buf;
383 }
384 
385 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
386 {
387 	u32 domain;
388 	struct sk_buff *buf;
389 	struct tipc_node *n_ptr;
390 	struct tipc_link_info link_info;
391 	u32 payload_size;
392 
393 	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
394 		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
395 
396 	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
397 	if (!tipc_addr_domain_valid(domain))
398 		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
399 						   " (network address)");
400 
401 	if (!tipc_own_addr)
402 		return tipc_cfg_reply_none();
403 
404 	spin_lock_bh(&node_list_lock);
405 	/* Get space for all unicast links + broadcast link */
406 	payload_size = TLV_SPACE((sizeof(link_info)) * (tipc_num_links + 1));
407 	if (payload_size > 32768u) {
408 		spin_unlock_bh(&node_list_lock);
409 		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
410 						   " (too many links)");
411 	}
412 	spin_unlock_bh(&node_list_lock);
413 
414 	buf = tipc_cfg_reply_alloc(payload_size);
415 	if (!buf)
416 		return NULL;
417 
418 	/* Add TLV for broadcast link */
419 	link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
420 	link_info.up = htonl(1);
421 	strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
422 	tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
423 
424 	/* Add TLVs for any other links in scope */
425 	rcu_read_lock();
426 	list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
427 		u32 i;
428 
429 		if (!tipc_in_scope(domain, n_ptr->addr))
430 			continue;
431 		tipc_node_lock(n_ptr);
432 		for (i = 0; i < MAX_BEARERS; i++) {
433 			if (!n_ptr->links[i])
434 				continue;
435 			link_info.dest = htonl(n_ptr->addr);
436 			link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
437 			strcpy(link_info.str, n_ptr->links[i]->name);
438 			tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
439 					    &link_info, sizeof(link_info));
440 		}
441 		tipc_node_unlock(n_ptr);
442 	}
443 	rcu_read_unlock();
444 	return buf;
445 }
446 
447 /**
448  * tipc_node_get_linkname - get the name of a link
449  *
450  * @bearer_id: id of the bearer
451  * @node: peer node address
452  * @linkname: link name output buffer
453  *
454  * Returns 0 on success
455  */
456 int tipc_node_get_linkname(u32 bearer_id, u32 addr, char *linkname, size_t len)
457 {
458 	struct tipc_link *link;
459 	struct tipc_node *node = tipc_node_find(addr);
460 
461 	if ((bearer_id >= MAX_BEARERS) || !node)
462 		return -EINVAL;
463 	tipc_node_lock(node);
464 	link = node->links[bearer_id];
465 	if (link) {
466 		strncpy(linkname, link->name, len);
467 		tipc_node_unlock(node);
468 		return 0;
469 	}
470 	tipc_node_unlock(node);
471 	return -EINVAL;
472 }
473 
474 void tipc_node_unlock(struct tipc_node *node)
475 {
476 	LIST_HEAD(nsub_list);
477 	u32 addr = 0;
478 
479 	if (likely(!node->action_flags)) {
480 		spin_unlock_bh(&node->lock);
481 		return;
482 	}
483 
484 	if (node->action_flags & TIPC_NOTIFY_NODE_DOWN) {
485 		list_replace_init(&node->nsub, &nsub_list);
486 		node->action_flags &= ~TIPC_NOTIFY_NODE_DOWN;
487 	}
488 	if (node->action_flags & TIPC_NOTIFY_NODE_UP) {
489 		node->action_flags &= ~TIPC_NOTIFY_NODE_UP;
490 		addr = node->addr;
491 	}
492 	spin_unlock_bh(&node->lock);
493 
494 	if (!list_empty(&nsub_list))
495 		tipc_nodesub_notify(&nsub_list);
496 	if (addr)
497 		tipc_named_node_up(addr);
498 }
499