xref: /openbmc/linux/net/tipc/node.c (revision ce932d0c5589e9766e089c22c66890dfc48fbd94) 
1 /*
2  * net/tipc/node.c: TIPC node management routines
3  *
4  * Copyright (c) 2000-2006, Ericsson AB
5  * Copyright (c) 2005-2006, 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 "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 DEFINE_SPINLOCK(node_create_lock);
48 
49 static struct hlist_head node_htable[NODE_HTABLE_SIZE];
50 LIST_HEAD(tipc_node_list);
51 static u32 tipc_num_nodes;
52 
53 static atomic_t tipc_num_links = ATOMIC_INIT(0);
54 
55 /*
56  * A trivial power-of-two bitmask technique is used for speed, since this
57  * operation is done for every incoming TIPC packet. The number of hash table
58  * entries has been chosen so that no hash chain exceeds 8 nodes and will
59  * usually be much smaller (typically only a single node).
60  */
61 static inline unsigned int tipc_hashfn(u32 addr)
62 {
63 	return addr & (NODE_HTABLE_SIZE - 1);
64 }
65 
66 /*
67  * tipc_node_find - locate specified node object, if it exists
68  */
69 
70 struct tipc_node *tipc_node_find(u32 addr)
71 {
72 	struct tipc_node *node;
73 	struct hlist_node *pos;
74 
75 	if (unlikely(!in_own_cluster(addr)))
76 		return NULL;
77 
78 	hlist_for_each_entry(node, pos, &node_htable[tipc_hashfn(addr)], hash) {
79 		if (node->addr == addr)
80 			return node;
81 	}
82 	return NULL;
83 }
84 
85 /**
86  * tipc_node_create - create neighboring node
87  *
88  * Currently, this routine is called by neighbor discovery code, which holds
89  * net_lock for reading only.  We must take node_create_lock to ensure a node
90  * isn't created twice if two different bearers discover the node at the same
91  * time.  (It would be preferable to switch to holding net_lock in write mode,
92  * but this is a non-trivial change.)
93  */
94 
95 struct tipc_node *tipc_node_create(u32 addr)
96 {
97 	struct tipc_node *n_ptr, *temp_node;
98 
99 	spin_lock_bh(&node_create_lock);
100 
101 	n_ptr = tipc_node_find(addr);
102 	if (n_ptr) {
103 		spin_unlock_bh(&node_create_lock);
104 		return n_ptr;
105 	}
106 
107 	n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
108 	if (!n_ptr) {
109 		spin_unlock_bh(&node_create_lock);
110 		warn("Node creation failed, no memory\n");
111 		return NULL;
112 	}
113 
114 	n_ptr->addr = addr;
115 	spin_lock_init(&n_ptr->lock);
116 	INIT_HLIST_NODE(&n_ptr->hash);
117 	INIT_LIST_HEAD(&n_ptr->list);
118 	INIT_LIST_HEAD(&n_ptr->nsub);
119 
120 	hlist_add_head(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
121 
122 	list_for_each_entry(temp_node, &tipc_node_list, list) {
123 		if (n_ptr->addr < temp_node->addr)
124 			break;
125 	}
126 	list_add_tail(&n_ptr->list, &temp_node->list);
127 	n_ptr->block_setup = WAIT_PEER_DOWN;
128 	n_ptr->signature = INVALID_NODE_SIG;
129 
130 	tipc_num_nodes++;
131 
132 	spin_unlock_bh(&node_create_lock);
133 	return n_ptr;
134 }
135 
136 void tipc_node_delete(struct tipc_node *n_ptr)
137 {
138 	list_del(&n_ptr->list);
139 	hlist_del(&n_ptr->hash);
140 	kfree(n_ptr);
141 
142 	tipc_num_nodes--;
143 }
144 
145 
146 /**
147  * tipc_node_link_up - handle addition of link
148  *
149  * Link becomes active (alone or shared) or standby, depending on its priority.
150  */
151 
152 void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
153 {
154 	struct tipc_link **active = &n_ptr->active_links[0];
155 
156 	n_ptr->working_links++;
157 
158 	info("Established link <%s> on network plane %c\n",
159 	     l_ptr->name, l_ptr->b_ptr->net_plane);
160 
161 	if (!active[0]) {
162 		active[0] = active[1] = l_ptr;
163 		node_established_contact(n_ptr);
164 		return;
165 	}
166 	if (l_ptr->priority < active[0]->priority) {
167 		info("New link <%s> becomes standby\n", l_ptr->name);
168 		return;
169 	}
170 	tipc_link_send_duplicate(active[0], l_ptr);
171 	if (l_ptr->priority == active[0]->priority) {
172 		active[0] = l_ptr;
173 		return;
174 	}
175 	info("Old link <%s> becomes standby\n", active[0]->name);
176 	if (active[1] != active[0])
177 		info("Old link <%s> becomes standby\n", active[1]->name);
178 	active[0] = active[1] = l_ptr;
179 }
180 
181 /**
182  * node_select_active_links - select active link
183  */
184 
185 static void node_select_active_links(struct tipc_node *n_ptr)
186 {
187 	struct tipc_link **active = &n_ptr->active_links[0];
188 	u32 i;
189 	u32 highest_prio = 0;
190 
191 	active[0] = active[1] = NULL;
192 
193 	for (i = 0; i < MAX_BEARERS; i++) {
194 		struct tipc_link *l_ptr = n_ptr->links[i];
195 
196 		if (!l_ptr || !tipc_link_is_up(l_ptr) ||
197 		    (l_ptr->priority < highest_prio))
198 			continue;
199 
200 		if (l_ptr->priority > highest_prio) {
201 			highest_prio = l_ptr->priority;
202 			active[0] = active[1] = l_ptr;
203 		} else {
204 			active[1] = l_ptr;
205 		}
206 	}
207 }
208 
209 /**
210  * tipc_node_link_down - handle loss of link
211  */
212 
213 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
214 {
215 	struct tipc_link **active;
216 
217 	n_ptr->working_links--;
218 
219 	if (!tipc_link_is_active(l_ptr)) {
220 		info("Lost standby link <%s> on network plane %c\n",
221 		     l_ptr->name, l_ptr->b_ptr->net_plane);
222 		return;
223 	}
224 	info("Lost link <%s> on network plane %c\n",
225 		l_ptr->name, l_ptr->b_ptr->net_plane);
226 
227 	active = &n_ptr->active_links[0];
228 	if (active[0] == l_ptr)
229 		active[0] = active[1];
230 	if (active[1] == l_ptr)
231 		active[1] = active[0];
232 	if (active[0] == l_ptr)
233 		node_select_active_links(n_ptr);
234 	if (tipc_node_is_up(n_ptr))
235 		tipc_link_changeover(l_ptr);
236 	else
237 		node_lost_contact(n_ptr);
238 }
239 
240 int tipc_node_active_links(struct tipc_node *n_ptr)
241 {
242 	return n_ptr->active_links[0] != NULL;
243 }
244 
245 int tipc_node_redundant_links(struct tipc_node *n_ptr)
246 {
247 	return n_ptr->working_links > 1;
248 }
249 
250 int tipc_node_is_up(struct tipc_node *n_ptr)
251 {
252 	return tipc_node_active_links(n_ptr);
253 }
254 
255 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
256 {
257 	n_ptr->links[l_ptr->b_ptr->identity] = l_ptr;
258 	atomic_inc(&tipc_num_links);
259 	n_ptr->link_cnt++;
260 }
261 
262 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
263 {
264 	n_ptr->links[l_ptr->b_ptr->identity] = NULL;
265 	atomic_dec(&tipc_num_links);
266 	n_ptr->link_cnt--;
267 }
268 
269 static void node_established_contact(struct tipc_node *n_ptr)
270 {
271 	tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr);
272 
273 	if (n_ptr->bclink.supportable) {
274 		n_ptr->bclink.acked = tipc_bclink_get_last_sent();
275 		tipc_bclink_add_node(n_ptr->addr);
276 		n_ptr->bclink.supported = 1;
277 	}
278 }
279 
280 static void node_name_purge_complete(unsigned long node_addr)
281 {
282 	struct tipc_node *n_ptr;
283 
284 	read_lock_bh(&tipc_net_lock);
285 	n_ptr = tipc_node_find(node_addr);
286 	if (n_ptr) {
287 		tipc_node_lock(n_ptr);
288 		n_ptr->block_setup &= ~WAIT_NAMES_GONE;
289 		tipc_node_unlock(n_ptr);
290 	}
291 	read_unlock_bh(&tipc_net_lock);
292 }
293 
294 static void node_lost_contact(struct tipc_node *n_ptr)
295 {
296 	char addr_string[16];
297 	u32 i;
298 
299 	info("Lost contact with %s\n",
300 	     tipc_addr_string_fill(addr_string, n_ptr->addr));
301 
302 	/* Flush broadcast link info associated with lost node */
303 
304 	if (n_ptr->bclink.supported) {
305 		while (n_ptr->bclink.deferred_head) {
306 			struct sk_buff *buf = n_ptr->bclink.deferred_head;
307 			n_ptr->bclink.deferred_head = buf->next;
308 			kfree_skb(buf);
309 		}
310 		n_ptr->bclink.deferred_size = 0;
311 
312 		if (n_ptr->bclink.defragm) {
313 			kfree_skb(n_ptr->bclink.defragm);
314 			n_ptr->bclink.defragm = NULL;
315 		}
316 
317 		tipc_bclink_remove_node(n_ptr->addr);
318 		tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
319 
320 		n_ptr->bclink.supported = 0;
321 	}
322 
323 	/* Abort link changeover */
324 	for (i = 0; i < MAX_BEARERS; i++) {
325 		struct tipc_link *l_ptr = n_ptr->links[i];
326 		if (!l_ptr)
327 			continue;
328 		l_ptr->reset_checkpoint = l_ptr->next_in_no;
329 		l_ptr->exp_msg_count = 0;
330 		tipc_link_reset_fragments(l_ptr);
331 	}
332 
333 	/* Notify subscribers */
334 	tipc_nodesub_notify(n_ptr);
335 
336 	/* Prevent re-contact with node until cleanup is done */
337 
338 	n_ptr->block_setup = WAIT_PEER_DOWN | WAIT_NAMES_GONE;
339 	tipc_k_signal((Handler)node_name_purge_complete, n_ptr->addr);
340 }
341 
342 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
343 {
344 	u32 domain;
345 	struct sk_buff *buf;
346 	struct tipc_node *n_ptr;
347 	struct tipc_node_info node_info;
348 	u32 payload_size;
349 
350 	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
351 		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
352 
353 	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
354 	if (!tipc_addr_domain_valid(domain))
355 		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
356 						   " (network address)");
357 
358 	read_lock_bh(&tipc_net_lock);
359 	if (!tipc_num_nodes) {
360 		read_unlock_bh(&tipc_net_lock);
361 		return tipc_cfg_reply_none();
362 	}
363 
364 	/* For now, get space for all other nodes */
365 
366 	payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
367 	if (payload_size > 32768u) {
368 		read_unlock_bh(&tipc_net_lock);
369 		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
370 						   " (too many nodes)");
371 	}
372 	buf = tipc_cfg_reply_alloc(payload_size);
373 	if (!buf) {
374 		read_unlock_bh(&tipc_net_lock);
375 		return NULL;
376 	}
377 
378 	/* Add TLVs for all nodes in scope */
379 
380 	list_for_each_entry(n_ptr, &tipc_node_list, list) {
381 		if (!tipc_in_scope(domain, n_ptr->addr))
382 			continue;
383 		node_info.addr = htonl(n_ptr->addr);
384 		node_info.up = htonl(tipc_node_is_up(n_ptr));
385 		tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
386 				    &node_info, sizeof(node_info));
387 	}
388 
389 	read_unlock_bh(&tipc_net_lock);
390 	return buf;
391 }
392 
393 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
394 {
395 	u32 domain;
396 	struct sk_buff *buf;
397 	struct tipc_node *n_ptr;
398 	struct tipc_link_info link_info;
399 	u32 payload_size;
400 
401 	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
402 		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
403 
404 	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
405 	if (!tipc_addr_domain_valid(domain))
406 		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
407 						   " (network address)");
408 
409 	if (!tipc_own_addr)
410 		return tipc_cfg_reply_none();
411 
412 	read_lock_bh(&tipc_net_lock);
413 
414 	/* Get space for all unicast links + broadcast link */
415 
416 	payload_size = TLV_SPACE(sizeof(link_info)) *
417 		(atomic_read(&tipc_num_links) + 1);
418 	if (payload_size > 32768u) {
419 		read_unlock_bh(&tipc_net_lock);
420 		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
421 						   " (too many links)");
422 	}
423 	buf = tipc_cfg_reply_alloc(payload_size);
424 	if (!buf) {
425 		read_unlock_bh(&tipc_net_lock);
426 		return NULL;
427 	}
428 
429 	/* Add TLV for broadcast link */
430 
431 	link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
432 	link_info.up = htonl(1);
433 	strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
434 	tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
435 
436 	/* Add TLVs for any other links in scope */
437 
438 	list_for_each_entry(n_ptr, &tipc_node_list, list) {
439 		u32 i;
440 
441 		if (!tipc_in_scope(domain, n_ptr->addr))
442 			continue;
443 		tipc_node_lock(n_ptr);
444 		for (i = 0; i < MAX_BEARERS; i++) {
445 			if (!n_ptr->links[i])
446 				continue;
447 			link_info.dest = htonl(n_ptr->addr);
448 			link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
449 			strcpy(link_info.str, n_ptr->links[i]->name);
450 			tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
451 					    &link_info, sizeof(link_info));
452 		}
453 		tipc_node_unlock(n_ptr);
454 	}
455 
456 	read_unlock_bh(&tipc_net_lock);
457 	return buf;
458 }
459