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node.c
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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 
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  */
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 
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  pr_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 
134 void 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 
148 void 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  pr_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  pr_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  pr_info("Old link <%s> becomes standby\n", active[0]->name);
172  if (active[1] != active[0])
173  pr_info("Old link <%s> becomes standby\n", active[1]->name);
174  active[0] = active[1] = l_ptr;
175 }
176 
180 static 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 
207 void 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  pr_info("Lost standby link <%s> on network plane %c\n",
215  l_ptr->name, l_ptr->b_ptr->net_plane);
216  return;
217  }
218  pr_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 
235 {
236  return n_ptr->active_links[0] != NULL;
237 }
238 
240 {
241  return n_ptr->working_links > 1;
242 }
243 
244 int tipc_node_is_up(struct tipc_node *n_ptr)
245 {
246  return tipc_node_active_links(n_ptr);
247 }
248 
249 void 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 
256 void 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 
263 static void node_established_contact(struct tipc_node *n_ptr)
264 {
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 
274 static 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 
288 static void node_lost_contact(struct tipc_node *n_ptr)
289 {
290  char addr_string[16];
291  u32 i;
292 
293  pr_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 
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;
324  }
325 
326  /* Notify subscribers */
327  tipc_nodesub_notify(n_ptr);
328 
329  /* Prevent re-contact with node until cleanup is done */
331  tipc_k_signal((Handler)node_name_purge_complete, n_ptr->addr);
332 }
333 
334 struct 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;
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 
351  if (!tipc_num_nodes) {
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) {
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) {
366  return NULL;
367  }
368 
369  /* Add TLVs for all nodes in scope */
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));
376  &node_info, sizeof(node_info));
377  }
378 
380  return buf;
381 }
382 
383 struct 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;
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 
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) {
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) {
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);
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 */
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);
438  &link_info, sizeof(link_info));
439  }
440  tipc_node_unlock(n_ptr);
441  }
442 
444  return buf;
445 }