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 */ 69 struct 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 */ 93 struct 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 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 } 142 143 /** 144 * tipc_node_link_up - handle addition of link 145 * 146 * Link becomes active (alone or shared) or standby, depending on its priority. 147 */ 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 } 176 177 /** 178 * node_select_active_links - select active link 179 */ 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 } 203 204 /** 205 * tipc_node_link_down - handle loss of link 206 */ 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 } 233 234 int tipc_node_active_links(struct tipc_node *n_ptr) 235 { 236 return n_ptr->active_links[0] != NULL; 237 } 238 239 int tipc_node_redundant_links(struct tipc_node *n_ptr) 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 { 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 } 273 274 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 } 309 310 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 } 333 334 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; 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 } 382 383 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; 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 } 446