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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
44static void node_lost_contact(struct tipc_node *n_ptr);
45static void node_established_contact(struct tipc_node *n_ptr);
46
47static DEFINE_SPINLOCK(node_create_lock);
48
49static struct hlist_head node_htable[NODE_HTABLE_SIZE];
50LIST_HEAD(tipc_node_list);
51static u32 tipc_num_nodes;
52
53static 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 */
61static 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 */
69struct tipc_node *tipc_node_find(u32 addr)
70{
71 struct tipc_node *node;
72 struct hlist_node *pos;
73
74 if (unlikely(!in_own_cluster_exact(addr)))
75 return NULL;
76
77 hlist_for_each_entry(node, pos, &node_htable[tipc_hashfn(addr)], hash) {
78 if (node->addr == addr)
79 return node;
80 }
81 return NULL;
82}
83
84/**
85 * tipc_node_create - create neighboring node
86 *
87 * Currently, this routine is called by neighbor discovery code, which holds
88 * net_lock for reading only. We must take node_create_lock to ensure a node
89 * isn't created twice if two different bearers discover the node at the same
90 * time. (It would be preferable to switch to holding net_lock in write mode,
91 * but this is a non-trivial change.)
92 */
93struct tipc_node *tipc_node_create(u32 addr)
94{
95 struct tipc_node *n_ptr, *temp_node;
96
97 spin_lock_bh(&node_create_lock);
98
99 n_ptr = tipc_node_find(addr);
100 if (n_ptr) {
101 spin_unlock_bh(&node_create_lock);
102 return n_ptr;
103 }
104
105 n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
106 if (!n_ptr) {
107 spin_unlock_bh(&node_create_lock);
108 warn("Node creation failed, no memory\n");
109 return NULL;
110 }
111
112 n_ptr->addr = addr;
113 spin_lock_init(&n_ptr->lock);
114 INIT_HLIST_NODE(&n_ptr->hash);
115 INIT_LIST_HEAD(&n_ptr->list);
116 INIT_LIST_HEAD(&n_ptr->nsub);
117
118 hlist_add_head(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
119
120 list_for_each_entry(temp_node, &tipc_node_list, list) {
121 if (n_ptr->addr < temp_node->addr)
122 break;
123 }
124 list_add_tail(&n_ptr->list, &temp_node->list);
125 n_ptr->block_setup = WAIT_PEER_DOWN;
126 n_ptr->signature = INVALID_NODE_SIG;
127
128 tipc_num_nodes++;
129
130 spin_unlock_bh(&node_create_lock);
131 return n_ptr;
132}
133
134void tipc_node_delete(struct tipc_node *n_ptr)
135{
136 list_del(&n_ptr->list);
137 hlist_del(&n_ptr->hash);
138 kfree(n_ptr);
139
140 tipc_num_nodes--;
141}
142
143/**
144 * tipc_node_link_up - handle addition of link
145 *
146 * Link becomes active (alone or shared) or standby, depending on its priority.
147 */
148void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
149{
150 struct tipc_link **active = &n_ptr->active_links[0];
151
152 n_ptr->working_links++;
153
154 info("Established link <%s> on network plane %c\n",
155 l_ptr->name, l_ptr->b_ptr->net_plane);
156
157 if (!active[0]) {
158 active[0] = active[1] = l_ptr;
159 node_established_contact(n_ptr);
160 return;
161 }
162 if (l_ptr->priority < active[0]->priority) {
163 info("New link <%s> becomes standby\n", l_ptr->name);
164 return;
165 }
166 tipc_link_send_duplicate(active[0], l_ptr);
167 if (l_ptr->priority == active[0]->priority) {
168 active[0] = l_ptr;
169 return;
170 }
171 info("Old link <%s> becomes standby\n", active[0]->name);
172 if (active[1] != active[0])
173 info("Old link <%s> becomes standby\n", active[1]->name);
174 active[0] = active[1] = l_ptr;
175}
176
177/**
178 * node_select_active_links - select active link
179 */
180static void node_select_active_links(struct tipc_node *n_ptr)
181{
182 struct tipc_link **active = &n_ptr->active_links[0];
183 u32 i;
184 u32 highest_prio = 0;
185
186 active[0] = active[1] = NULL;
187
188 for (i = 0; i < MAX_BEARERS; i++) {
189 struct tipc_link *l_ptr = n_ptr->links[i];
190
191 if (!l_ptr || !tipc_link_is_up(l_ptr) ||
192 (l_ptr->priority < highest_prio))
193 continue;
194
195 if (l_ptr->priority > highest_prio) {
196 highest_prio = l_ptr->priority;
197 active[0] = active[1] = l_ptr;
198 } else {
199 active[1] = l_ptr;
200 }
201 }
202}
203
204/**
205 * tipc_node_link_down - handle loss of link
206 */
207void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
208{
209 struct tipc_link **active;
210
211 n_ptr->working_links--;
212
213 if (!tipc_link_is_active(l_ptr)) {
214 info("Lost standby link <%s> on network plane %c\n",
215 l_ptr->name, l_ptr->b_ptr->net_plane);
216 return;
217 }
218 info("Lost link <%s> on network plane %c\n",
219 l_ptr->name, l_ptr->b_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_changeover(l_ptr);
230 else
231 node_lost_contact(n_ptr);
232}
233
234int tipc_node_active_links(struct tipc_node *n_ptr)
235{
236 return n_ptr->active_links[0] != NULL;
237}
238
239int tipc_node_redundant_links(struct tipc_node *n_ptr)
240{
241 return n_ptr->working_links > 1;
242}
243
244int tipc_node_is_up(struct tipc_node *n_ptr)
245{
246 return tipc_node_active_links(n_ptr);
247}
248
249void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
250{
251 n_ptr->links[l_ptr->b_ptr->identity] = l_ptr;
252 atomic_inc(&tipc_num_links);
253 n_ptr->link_cnt++;
254}
255
256void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
257{
258 n_ptr->links[l_ptr->b_ptr->identity] = NULL;
259 atomic_dec(&tipc_num_links);
260 n_ptr->link_cnt--;
261}
262
263static void node_established_contact(struct tipc_node *n_ptr)
264{
265 tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr);
266
267 if (n_ptr->bclink.supportable) {
268 n_ptr->bclink.acked = tipc_bclink_get_last_sent();
269 tipc_bclink_add_node(n_ptr->addr);
270 n_ptr->bclink.supported = 1;
271 }
272}
273
274static void node_name_purge_complete(unsigned long node_addr)
275{
276 struct tipc_node *n_ptr;
277
278 read_lock_bh(&tipc_net_lock);
279 n_ptr = tipc_node_find(node_addr);
280 if (n_ptr) {
281 tipc_node_lock(n_ptr);
282 n_ptr->block_setup &= ~WAIT_NAMES_GONE;
283 tipc_node_unlock(n_ptr);
284 }
285 read_unlock_bh(&tipc_net_lock);
286}
287
288static void node_lost_contact(struct tipc_node *n_ptr)
289{
290 char addr_string[16];
291 u32 i;
292
293 info("Lost contact with %s\n",
294 tipc_addr_string_fill(addr_string, n_ptr->addr));
295
296 /* Flush broadcast link info associated with lost node */
297 if (n_ptr->bclink.supported) {
298 while (n_ptr->bclink.deferred_head) {
299 struct sk_buff *buf = n_ptr->bclink.deferred_head;
300 n_ptr->bclink.deferred_head = buf->next;
301 kfree_skb(buf);
302 }
303 n_ptr->bclink.deferred_size = 0;
304
305 if (n_ptr->bclink.defragm) {
306 kfree_skb(n_ptr->bclink.defragm);
307 n_ptr->bclink.defragm = NULL;
308 }
309
310 tipc_bclink_remove_node(n_ptr->addr);
311 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
312
313 n_ptr->bclink.supported = 0;
314 }
315
316 /* Abort link changeover */
317 for (i = 0; i < MAX_BEARERS; i++) {
318 struct tipc_link *l_ptr = n_ptr->links[i];
319 if (!l_ptr)
320 continue;
321 l_ptr->reset_checkpoint = l_ptr->next_in_no;
322 l_ptr->exp_msg_count = 0;
323 tipc_link_reset_fragments(l_ptr);
324 }
325
326 /* Notify subscribers */
327 tipc_nodesub_notify(n_ptr);
328
329 /* Prevent re-contact with node until cleanup is done */
330 n_ptr->block_setup = WAIT_PEER_DOWN | WAIT_NAMES_GONE;
331 tipc_k_signal((Handler)node_name_purge_complete, n_ptr->addr);
332}
333
334struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
335{
336 u32 domain;
337 struct sk_buff *buf;
338 struct tipc_node *n_ptr;
339 struct tipc_node_info node_info;
340 u32 payload_size;
341
342 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
343 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
344
345 domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
346 if (!tipc_addr_domain_valid(domain))
347 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
348 " (network address)");
349
350 read_lock_bh(&tipc_net_lock);
351 if (!tipc_num_nodes) {
352 read_unlock_bh(&tipc_net_lock);
353 return tipc_cfg_reply_none();
354 }
355
356 /* For now, get space for all other nodes */
357 payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
358 if (payload_size > 32768u) {
359 read_unlock_bh(&tipc_net_lock);
360 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
361 " (too many nodes)");
362 }
363 buf = tipc_cfg_reply_alloc(payload_size);
364 if (!buf) {
365 read_unlock_bh(&tipc_net_lock);
366 return NULL;
367 }
368
369 /* Add TLVs for all nodes in scope */
370 list_for_each_entry(n_ptr, &tipc_node_list, list) {
371 if (!tipc_in_scope(domain, n_ptr->addr))
372 continue;
373 node_info.addr = htonl(n_ptr->addr);
374 node_info.up = htonl(tipc_node_is_up(n_ptr));
375 tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
376 &node_info, sizeof(node_info));
377 }
378
379 read_unlock_bh(&tipc_net_lock);
380 return buf;
381}
382
383struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
384{
385 u32 domain;
386 struct sk_buff *buf;
387 struct tipc_node *n_ptr;
388 struct tipc_link_info link_info;
389 u32 payload_size;
390
391 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
392 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
393
394 domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
395 if (!tipc_addr_domain_valid(domain))
396 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
397 " (network address)");
398
399 if (!tipc_own_addr)
400 return tipc_cfg_reply_none();
401
402 read_lock_bh(&tipc_net_lock);
403
404 /* Get space for all unicast links + broadcast link */
405 payload_size = TLV_SPACE(sizeof(link_info)) *
406 (atomic_read(&tipc_num_links) + 1);
407 if (payload_size > 32768u) {
408 read_unlock_bh(&tipc_net_lock);
409 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
410 " (too many links)");
411 }
412 buf = tipc_cfg_reply_alloc(payload_size);
413 if (!buf) {
414 read_unlock_bh(&tipc_net_lock);
415 return NULL;
416 }
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 list_for_each_entry(n_ptr, &tipc_node_list, list) {
426 u32 i;
427
428 if (!tipc_in_scope(domain, n_ptr->addr))
429 continue;
430 tipc_node_lock(n_ptr);
431 for (i = 0; i < MAX_BEARERS; i++) {
432 if (!n_ptr->links[i])
433 continue;
434 link_info.dest = htonl(n_ptr->addr);
435 link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
436 strcpy(link_info.str, n_ptr->links[i]->name);
437 tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
438 &link_info, sizeof(link_info));
439 }
440 tipc_node_unlock(n_ptr);
441 }
442
443 read_unlock_bh(&tipc_net_lock);
444 return buf;
445}