xref: /openbmc/linux/net/tipc/node.c (revision db181ce0) 
1 /*
2  * net/tipc/node.c: TIPC node management routines
3  *
4  * Copyright (c) 2000-2006, 2012 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 		return;
159 	}
160 	if (l_ptr->priority < active[0]->priority) {
161 		pr_info("New link <%s> becomes standby\n", l_ptr->name);
162 		return;
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 		return;
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 }
174 
175 /**
176  * node_select_active_links - select active link
177  */
178 static void node_select_active_links(struct tipc_node *n_ptr)
179 {
180 	struct tipc_link **active = &n_ptr->active_links[0];
181 	u32 i;
182 	u32 highest_prio = 0;
183 
184 	active[0] = active[1] = NULL;
185 
186 	for (i = 0; i < MAX_BEARERS; i++) {
187 		struct tipc_link *l_ptr = n_ptr->links[i];
188 
189 		if (!l_ptr || !tipc_link_is_up(l_ptr) ||
190 		    (l_ptr->priority < highest_prio))
191 			continue;
192 
193 		if (l_ptr->priority > highest_prio) {
194 			highest_prio = l_ptr->priority;
195 			active[0] = active[1] = l_ptr;
196 		} else {
197 			active[1] = l_ptr;
198 		}
199 	}
200 }
201 
202 /**
203  * tipc_node_link_down - handle loss of link
204  */
205 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
206 {
207 	struct tipc_link **active;
208 	u32 addr = n_ptr->addr;
209 
210 	n_ptr->working_links--;
211 	tipc_nametbl_withdraw(TIPC_LINK_STATE, addr, l_ptr->bearer_id, addr);
212 
213 	if (!tipc_link_is_active(l_ptr)) {
214 		pr_info("Lost standby link <%s> on network plane %c\n",
215 			l_ptr->name, l_ptr->net_plane);
216 		return;
217 	}
218 	pr_info("Lost link <%s> on network plane %c\n",
219 		l_ptr->name, l_ptr->net_plane);
220 
221 	active = &n_ptr->active_links[0];
222 	if (active[0] == l_ptr)
223 		active[0] = active[1];
224 	if (active[1] == l_ptr)
225 		active[1] = active[0];
226 	if (active[0] == l_ptr)
227 		node_select_active_links(n_ptr);
228 	if (tipc_node_is_up(n_ptr))
229 		tipc_link_failover_send_queue(l_ptr);
230 	else
231 		node_lost_contact(n_ptr);
232 }
233 
234 int tipc_node_active_links(struct tipc_node *n_ptr)
235 {
236 	return n_ptr->active_links[0] != NULL;
237 }
238 
239 int tipc_node_is_up(struct tipc_node *n_ptr)
240 {
241 	return tipc_node_active_links(n_ptr);
242 }
243 
244 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
245 {
246 	n_ptr->links[l_ptr->bearer_id] = l_ptr;
247 	spin_lock_bh(&node_list_lock);
248 	tipc_num_links++;
249 	spin_unlock_bh(&node_list_lock);
250 	n_ptr->link_cnt++;
251 }
252 
253 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
254 {
255 	int i;
256 
257 	for (i = 0; i < MAX_BEARERS; i++) {
258 		if (l_ptr != n_ptr->links[i])
259 			continue;
260 		n_ptr->links[i] = NULL;
261 		spin_lock_bh(&node_list_lock);
262 		tipc_num_links--;
263 		spin_unlock_bh(&node_list_lock);
264 		n_ptr->link_cnt--;
265 	}
266 }
267 
268 static void node_established_contact(struct tipc_node *n_ptr)
269 {
270 	n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
271 	n_ptr->bclink.oos_state = 0;
272 	n_ptr->bclink.acked = tipc_bclink_get_last_sent();
273 	tipc_bclink_add_node(n_ptr->addr);
274 }
275 
276 static void node_lost_contact(struct tipc_node *n_ptr)
277 {
278 	char addr_string[16];
279 	u32 i;
280 
281 	pr_info("Lost contact with %s\n",
282 		tipc_addr_string_fill(addr_string, n_ptr->addr));
283 
284 	/* Flush broadcast link info associated with lost node */
285 	if (n_ptr->bclink.recv_permitted) {
286 		kfree_skb_list(n_ptr->bclink.deferred_head);
287 		n_ptr->bclink.deferred_size = 0;
288 
289 		if (n_ptr->bclink.reasm_buf) {
290 			kfree_skb(n_ptr->bclink.reasm_buf);
291 			n_ptr->bclink.reasm_buf = NULL;
292 		}
293 
294 		tipc_bclink_remove_node(n_ptr->addr);
295 		tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
296 
297 		n_ptr->bclink.recv_permitted = false;
298 	}
299 
300 	/* Abort link changeover */
301 	for (i = 0; i < MAX_BEARERS; i++) {
302 		struct tipc_link *l_ptr = n_ptr->links[i];
303 		if (!l_ptr)
304 			continue;
305 		l_ptr->reset_checkpoint = l_ptr->next_in_no;
306 		l_ptr->exp_msg_count = 0;
307 		tipc_link_reset_fragments(l_ptr);
308 	}
309 
310 	n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN;
311 
312 	/* Notify subscribers and prevent re-contact with node until
313 	 * cleanup is done.
314 	 */
315 	n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN |
316 			       TIPC_NOTIFY_NODE_DOWN;
317 }
318 
319 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
320 {
321 	u32 domain;
322 	struct sk_buff *buf;
323 	struct tipc_node *n_ptr;
324 	struct tipc_node_info node_info;
325 	u32 payload_size;
326 
327 	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
328 		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
329 
330 	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
331 	if (!tipc_addr_domain_valid(domain))
332 		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
333 						   " (network address)");
334 
335 	spin_lock_bh(&node_list_lock);
336 	if (!tipc_num_nodes) {
337 		spin_unlock_bh(&node_list_lock);
338 		return tipc_cfg_reply_none();
339 	}
340 
341 	/* For now, get space for all other nodes */
342 	payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
343 	if (payload_size > 32768u) {
344 		spin_unlock_bh(&node_list_lock);
345 		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
346 						   " (too many nodes)");
347 	}
348 	spin_unlock_bh(&node_list_lock);
349 
350 	buf = tipc_cfg_reply_alloc(payload_size);
351 	if (!buf)
352 		return NULL;
353 
354 	/* Add TLVs for all nodes in scope */
355 	rcu_read_lock();
356 	list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
357 		if (!tipc_in_scope(domain, n_ptr->addr))
358 			continue;
359 		node_info.addr = htonl(n_ptr->addr);
360 		node_info.up = htonl(tipc_node_is_up(n_ptr));
361 		tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
362 				    &node_info, sizeof(node_info));
363 	}
364 	rcu_read_unlock();
365 	return buf;
366 }
367 
368 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
369 {
370 	u32 domain;
371 	struct sk_buff *buf;
372 	struct tipc_node *n_ptr;
373 	struct tipc_link_info link_info;
374 	u32 payload_size;
375 
376 	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
377 		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
378 
379 	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
380 	if (!tipc_addr_domain_valid(domain))
381 		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
382 						   " (network address)");
383 
384 	if (!tipc_own_addr)
385 		return tipc_cfg_reply_none();
386 
387 	spin_lock_bh(&node_list_lock);
388 	/* Get space for all unicast links + broadcast link */
389 	payload_size = TLV_SPACE((sizeof(link_info)) * (tipc_num_links + 1));
390 	if (payload_size > 32768u) {
391 		spin_unlock_bh(&node_list_lock);
392 		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
393 						   " (too many links)");
394 	}
395 	spin_unlock_bh(&node_list_lock);
396 
397 	buf = tipc_cfg_reply_alloc(payload_size);
398 	if (!buf)
399 		return NULL;
400 
401 	/* Add TLV for broadcast link */
402 	link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
403 	link_info.up = htonl(1);
404 	strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
405 	tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
406 
407 	/* Add TLVs for any other links in scope */
408 	rcu_read_lock();
409 	list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
410 		u32 i;
411 
412 		if (!tipc_in_scope(domain, n_ptr->addr))
413 			continue;
414 		tipc_node_lock(n_ptr);
415 		for (i = 0; i < MAX_BEARERS; i++) {
416 			if (!n_ptr->links[i])
417 				continue;
418 			link_info.dest = htonl(n_ptr->addr);
419 			link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
420 			strcpy(link_info.str, n_ptr->links[i]->name);
421 			tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
422 					    &link_info, sizeof(link_info));
423 		}
424 		tipc_node_unlock(n_ptr);
425 	}
426 	rcu_read_unlock();
427 	return buf;
428 }
429 
430 /**
431  * tipc_node_get_linkname - get the name of a link
432  *
433  * @bearer_id: id of the bearer
434  * @node: peer node address
435  * @linkname: link name output buffer
436  *
437  * Returns 0 on success
438  */
439 int tipc_node_get_linkname(u32 bearer_id, u32 addr, char *linkname, size_t len)
440 {
441 	struct tipc_link *link;
442 	struct tipc_node *node = tipc_node_find(addr);
443 
444 	if ((bearer_id >= MAX_BEARERS) || !node)
445 		return -EINVAL;
446 	tipc_node_lock(node);
447 	link = node->links[bearer_id];
448 	if (link) {
449 		strncpy(linkname, link->name, len);
450 		tipc_node_unlock(node);
451 		return 0;
452 	}
453 	tipc_node_unlock(node);
454 	return -EINVAL;
455 }
456 
457 void tipc_node_unlock(struct tipc_node *node)
458 {
459 	LIST_HEAD(nsub_list);
460 	struct tipc_link *link;
461 	int pkt_sz = 0;
462 	u32 addr = 0;
463 
464 	if (likely(!node->action_flags)) {
465 		spin_unlock_bh(&node->lock);
466 		return;
467 	}
468 
469 	if (node->action_flags & TIPC_NOTIFY_NODE_DOWN) {
470 		list_replace_init(&node->nsub, &nsub_list);
471 		node->action_flags &= ~TIPC_NOTIFY_NODE_DOWN;
472 	}
473 	if (node->action_flags & TIPC_NOTIFY_NODE_UP) {
474 		link = node->active_links[0];
475 		node->action_flags &= ~TIPC_NOTIFY_NODE_UP;
476 		if (link) {
477 			pkt_sz = ((link->max_pkt - INT_H_SIZE) / ITEM_SIZE) *
478 				  ITEM_SIZE;
479 			addr = node->addr;
480 		}
481 	}
482 	spin_unlock_bh(&node->lock);
483 
484 	if (!list_empty(&nsub_list))
485 		tipc_nodesub_notify(&nsub_list);
486 	if (pkt_sz)
487 		tipc_named_node_up(pkt_sz, addr);
488 }
489