xref: /openbmc/linux/net/tipc/node.c (revision 97da55fc) 
1 /*
2  * net/tipc/node.c: TIPC node management routines
3  *
4  * Copyright (c) 2000-2006, 2012 Ericsson AB
5  * Copyright (c) 2005-2006, 2010-2011, 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 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 struct tipc_node *tipc_node_find(u32 addr)
70 {
71 	struct tipc_node *node;
72 
73 	if (unlikely(!in_own_cluster_exact(addr)))
74 		return NULL;
75 
76 	hlist_for_each_entry(node, &node_htable[tipc_hashfn(addr)], hash) {
77 		if (node->addr == addr)
78 			return node;
79 	}
80 	return NULL;
81 }
82 
83 /**
84  * tipc_node_create - create neighboring node
85  *
86  * Currently, this routine is called by neighbor discovery code, which holds
87  * net_lock for reading only.  We must take node_create_lock to ensure a node
88  * isn't created twice if two different bearers discover the node at the same
89  * time.  (It would be preferable to switch to holding net_lock in write mode,
90  * but this is a non-trivial change.)
91  */
92 struct tipc_node *tipc_node_create(u32 addr)
93 {
94 	struct tipc_node *n_ptr, *temp_node;
95 
96 	spin_lock_bh(&node_create_lock);
97 
98 	n_ptr = tipc_node_find(addr);
99 	if (n_ptr) {
100 		spin_unlock_bh(&node_create_lock);
101 		return n_ptr;
102 	}
103 
104 	n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
105 	if (!n_ptr) {
106 		spin_unlock_bh(&node_create_lock);
107 		pr_warn("Node creation failed, no memory\n");
108 		return NULL;
109 	}
110 
111 	n_ptr->addr = addr;
112 	spin_lock_init(&n_ptr->lock);
113 	INIT_HLIST_NODE(&n_ptr->hash);
114 	INIT_LIST_HEAD(&n_ptr->list);
115 	INIT_LIST_HEAD(&n_ptr->nsub);
116 
117 	hlist_add_head(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
118 
119 	list_for_each_entry(temp_node, &tipc_node_list, list) {
120 		if (n_ptr->addr < temp_node->addr)
121 			break;
122 	}
123 	list_add_tail(&n_ptr->list, &temp_node->list);
124 	n_ptr->block_setup = WAIT_PEER_DOWN;
125 	n_ptr->signature = INVALID_NODE_SIG;
126 
127 	tipc_num_nodes++;
128 
129 	spin_unlock_bh(&node_create_lock);
130 	return n_ptr;
131 }
132 
133 void tipc_node_delete(struct tipc_node *n_ptr)
134 {
135 	list_del(&n_ptr->list);
136 	hlist_del(&n_ptr->hash);
137 	kfree(n_ptr);
138 
139 	tipc_num_nodes--;
140 }
141 
142 /**
143  * tipc_node_link_up - handle addition of link
144  *
145  * Link becomes active (alone or shared) or standby, depending on its priority.
146  */
147 void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
148 {
149 	struct tipc_link **active = &n_ptr->active_links[0];
150 
151 	n_ptr->working_links++;
152 
153 	pr_info("Established link <%s> on network plane %c\n",
154 		l_ptr->name, l_ptr->b_ptr->net_plane);
155 
156 	if (!active[0]) {
157 		active[0] = active[1] = l_ptr;
158 		node_established_contact(n_ptr);
159 		return;
160 	}
161 	if (l_ptr->priority < active[0]->priority) {
162 		pr_info("New link <%s> becomes standby\n", l_ptr->name);
163 		return;
164 	}
165 	tipc_link_send_duplicate(active[0], l_ptr);
166 	if (l_ptr->priority == active[0]->priority) {
167 		active[0] = l_ptr;
168 		return;
169 	}
170 	pr_info("Old link <%s> becomes standby\n", active[0]->name);
171 	if (active[1] != active[0])
172 		pr_info("Old link <%s> becomes standby\n", active[1]->name);
173 	active[0] = active[1] = l_ptr;
174 }
175 
176 /**
177  * node_select_active_links - select active link
178  */
179 static void node_select_active_links(struct tipc_node *n_ptr)
180 {
181 	struct tipc_link **active = &n_ptr->active_links[0];
182 	u32 i;
183 	u32 highest_prio = 0;
184 
185 	active[0] = active[1] = NULL;
186 
187 	for (i = 0; i < MAX_BEARERS; i++) {
188 		struct tipc_link *l_ptr = n_ptr->links[i];
189 
190 		if (!l_ptr || !tipc_link_is_up(l_ptr) ||
191 		    (l_ptr->priority < highest_prio))
192 			continue;
193 
194 		if (l_ptr->priority > highest_prio) {
195 			highest_prio = l_ptr->priority;
196 			active[0] = active[1] = l_ptr;
197 		} else {
198 			active[1] = l_ptr;
199 		}
200 	}
201 }
202 
203 /**
204  * tipc_node_link_down - handle loss of link
205  */
206 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
207 {
208 	struct tipc_link **active;
209 
210 	n_ptr->working_links--;
211 
212 	if (!tipc_link_is_active(l_ptr)) {
213 		pr_info("Lost standby link <%s> on network plane %c\n",
214 			l_ptr->name, l_ptr->b_ptr->net_plane);
215 		return;
216 	}
217 	pr_info("Lost link <%s> on network plane %c\n",
218 		l_ptr->name, l_ptr->b_ptr->net_plane);
219 
220 	active = &n_ptr->active_links[0];
221 	if (active[0] == l_ptr)
222 		active[0] = active[1];
223 	if (active[1] == l_ptr)
224 		active[1] = active[0];
225 	if (active[0] == l_ptr)
226 		node_select_active_links(n_ptr);
227 	if (tipc_node_is_up(n_ptr))
228 		tipc_link_changeover(l_ptr);
229 	else
230 		node_lost_contact(n_ptr);
231 }
232 
233 int tipc_node_active_links(struct tipc_node *n_ptr)
234 {
235 	return n_ptr->active_links[0] != NULL;
236 }
237 
238 int tipc_node_redundant_links(struct tipc_node *n_ptr)
239 {
240 	return n_ptr->working_links > 1;
241 }
242 
243 int tipc_node_is_up(struct tipc_node *n_ptr)
244 {
245 	return tipc_node_active_links(n_ptr);
246 }
247 
248 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
249 {
250 	n_ptr->links[l_ptr->b_ptr->identity] = l_ptr;
251 	atomic_inc(&tipc_num_links);
252 	n_ptr->link_cnt++;
253 }
254 
255 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
256 {
257 	n_ptr->links[l_ptr->b_ptr->identity] = NULL;
258 	atomic_dec(&tipc_num_links);
259 	n_ptr->link_cnt--;
260 }
261 
262 static void node_established_contact(struct tipc_node *n_ptr)
263 {
264 	tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr);
265 	n_ptr->bclink.oos_state = 0;
266 	n_ptr->bclink.acked = tipc_bclink_get_last_sent();
267 	tipc_bclink_add_node(n_ptr->addr);
268 }
269 
270 static void node_name_purge_complete(unsigned long node_addr)
271 {
272 	struct tipc_node *n_ptr;
273 
274 	read_lock_bh(&tipc_net_lock);
275 	n_ptr = tipc_node_find(node_addr);
276 	if (n_ptr) {
277 		tipc_node_lock(n_ptr);
278 		n_ptr->block_setup &= ~WAIT_NAMES_GONE;
279 		tipc_node_unlock(n_ptr);
280 	}
281 	read_unlock_bh(&tipc_net_lock);
282 }
283 
284 static void node_lost_contact(struct tipc_node *n_ptr)
285 {
286 	char addr_string[16];
287 	u32 i;
288 
289 	pr_info("Lost contact with %s\n",
290 		tipc_addr_string_fill(addr_string, n_ptr->addr));
291 
292 	/* Flush broadcast link info associated with lost node */
293 	if (n_ptr->bclink.recv_permitted) {
294 		while (n_ptr->bclink.deferred_head) {
295 			struct sk_buff *buf = n_ptr->bclink.deferred_head;
296 			n_ptr->bclink.deferred_head = buf->next;
297 			kfree_skb(buf);
298 		}
299 		n_ptr->bclink.deferred_size = 0;
300 
301 		if (n_ptr->bclink.defragm) {
302 			kfree_skb(n_ptr->bclink.defragm);
303 			n_ptr->bclink.defragm = NULL;
304 		}
305 
306 		tipc_bclink_remove_node(n_ptr->addr);
307 		tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
308 
309 		n_ptr->bclink.recv_permitted = false;
310 	}
311 
312 	/* Abort link changeover */
313 	for (i = 0; i < MAX_BEARERS; i++) {
314 		struct tipc_link *l_ptr = n_ptr->links[i];
315 		if (!l_ptr)
316 			continue;
317 		l_ptr->reset_checkpoint = l_ptr->next_in_no;
318 		l_ptr->exp_msg_count = 0;
319 		tipc_link_reset_fragments(l_ptr);
320 	}
321 
322 	/* Notify subscribers */
323 	tipc_nodesub_notify(n_ptr);
324 
325 	/* Prevent re-contact with node until cleanup is done */
326 	n_ptr->block_setup = WAIT_PEER_DOWN | WAIT_NAMES_GONE;
327 	tipc_k_signal((Handler)node_name_purge_complete, n_ptr->addr);
328 }
329 
330 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
331 {
332 	u32 domain;
333 	struct sk_buff *buf;
334 	struct tipc_node *n_ptr;
335 	struct tipc_node_info node_info;
336 	u32 payload_size;
337 
338 	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
339 		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
340 
341 	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
342 	if (!tipc_addr_domain_valid(domain))
343 		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
344 						   " (network address)");
345 
346 	read_lock_bh(&tipc_net_lock);
347 	if (!tipc_num_nodes) {
348 		read_unlock_bh(&tipc_net_lock);
349 		return tipc_cfg_reply_none();
350 	}
351 
352 	/* For now, get space for all other nodes */
353 	payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
354 	if (payload_size > 32768u) {
355 		read_unlock_bh(&tipc_net_lock);
356 		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
357 						   " (too many nodes)");
358 	}
359 	buf = tipc_cfg_reply_alloc(payload_size);
360 	if (!buf) {
361 		read_unlock_bh(&tipc_net_lock);
362 		return NULL;
363 	}
364 
365 	/* Add TLVs for all nodes in scope */
366 	list_for_each_entry(n_ptr, &tipc_node_list, list) {
367 		if (!tipc_in_scope(domain, n_ptr->addr))
368 			continue;
369 		node_info.addr = htonl(n_ptr->addr);
370 		node_info.up = htonl(tipc_node_is_up(n_ptr));
371 		tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
372 				    &node_info, sizeof(node_info));
373 	}
374 
375 	read_unlock_bh(&tipc_net_lock);
376 	return buf;
377 }
378 
379 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
380 {
381 	u32 domain;
382 	struct sk_buff *buf;
383 	struct tipc_node *n_ptr;
384 	struct tipc_link_info link_info;
385 	u32 payload_size;
386 
387 	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
388 		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
389 
390 	domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
391 	if (!tipc_addr_domain_valid(domain))
392 		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
393 						   " (network address)");
394 
395 	if (!tipc_own_addr)
396 		return tipc_cfg_reply_none();
397 
398 	read_lock_bh(&tipc_net_lock);
399 
400 	/* Get space for all unicast links + broadcast link */
401 	payload_size = TLV_SPACE(sizeof(link_info)) *
402 		(atomic_read(&tipc_num_links) + 1);
403 	if (payload_size > 32768u) {
404 		read_unlock_bh(&tipc_net_lock);
405 		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
406 						   " (too many links)");
407 	}
408 	buf = tipc_cfg_reply_alloc(payload_size);
409 	if (!buf) {
410 		read_unlock_bh(&tipc_net_lock);
411 		return NULL;
412 	}
413 
414 	/* Add TLV for broadcast link */
415 	link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
416 	link_info.up = htonl(1);
417 	strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
418 	tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
419 
420 	/* Add TLVs for any other links in scope */
421 	list_for_each_entry(n_ptr, &tipc_node_list, list) {
422 		u32 i;
423 
424 		if (!tipc_in_scope(domain, n_ptr->addr))
425 			continue;
426 		tipc_node_lock(n_ptr);
427 		for (i = 0; i < MAX_BEARERS; i++) {
428 			if (!n_ptr->links[i])
429 				continue;
430 			link_info.dest = htonl(n_ptr->addr);
431 			link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
432 			strcpy(link_info.str, n_ptr->links[i]->name);
433 			tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
434 					    &link_info, sizeof(link_info));
435 		}
436 		tipc_node_unlock(n_ptr);
437 	}
438 
439 	read_unlock_bh(&tipc_net_lock);
440 	return buf;
441 }
442