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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 | } |