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 static void node_lost_contact(struct tipc_node *n_ptr); 43 static void node_established_contact(struct tipc_node *n_ptr); 44 45 static DEFINE_SPINLOCK(node_create_lock); 46 47 static struct hlist_head node_htable[NODE_HTABLE_SIZE]; 48 LIST_HEAD(tipc_node_list); 49 static u32 tipc_num_nodes; 50 51 static atomic_t tipc_num_links = ATOMIC_INIT(0); 52 u32 tipc_own_tag; 53 54 /** 55 * tipc_node_find - locate specified node object, if it exists 56 */ 57 58 struct tipc_node *tipc_node_find(u32 addr) 59 { 60 struct tipc_node *node; 61 struct hlist_node *pos; 62 63 if (unlikely(!in_own_cluster(addr))) 64 return NULL; 65 66 hlist_for_each_entry(node, pos, &node_htable[tipc_hashfn(addr)], hash) { 67 if (node->addr == addr) 68 return node; 69 } 70 return NULL; 71 } 72 73 /** 74 * tipc_node_create - create neighboring node 75 * 76 * Currently, this routine is called by neighbor discovery code, which holds 77 * net_lock for reading only. We must take node_create_lock to ensure a node 78 * isn't created twice if two different bearers discover the node at the same 79 * time. (It would be preferable to switch to holding net_lock in write mode, 80 * but this is a non-trivial change.) 81 */ 82 83 struct tipc_node *tipc_node_create(u32 addr) 84 { 85 struct tipc_node *n_ptr, *temp_node; 86 87 spin_lock_bh(&node_create_lock); 88 89 n_ptr = tipc_node_find(addr); 90 if (n_ptr) { 91 spin_unlock_bh(&node_create_lock); 92 return n_ptr; 93 } 94 95 n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC); 96 if (!n_ptr) { 97 spin_unlock_bh(&node_create_lock); 98 warn("Node creation failed, no memory\n"); 99 return NULL; 100 } 101 102 n_ptr->addr = addr; 103 spin_lock_init(&n_ptr->lock); 104 INIT_HLIST_NODE(&n_ptr->hash); 105 INIT_LIST_HEAD(&n_ptr->list); 106 INIT_LIST_HEAD(&n_ptr->nsub); 107 108 hlist_add_head(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]); 109 110 list_for_each_entry(temp_node, &tipc_node_list, list) { 111 if (n_ptr->addr < temp_node->addr) 112 break; 113 } 114 list_add_tail(&n_ptr->list, &temp_node->list); 115 n_ptr->block_setup = WAIT_PEER_DOWN; 116 117 tipc_num_nodes++; 118 119 spin_unlock_bh(&node_create_lock); 120 return n_ptr; 121 } 122 123 void tipc_node_delete(struct tipc_node *n_ptr) 124 { 125 list_del(&n_ptr->list); 126 hlist_del(&n_ptr->hash); 127 kfree(n_ptr); 128 129 tipc_num_nodes--; 130 } 131 132 133 /** 134 * tipc_node_link_up - handle addition of link 135 * 136 * Link becomes active (alone or shared) or standby, depending on its priority. 137 */ 138 139 void tipc_node_link_up(struct tipc_node *n_ptr, struct link *l_ptr) 140 { 141 struct link **active = &n_ptr->active_links[0]; 142 143 n_ptr->working_links++; 144 145 info("Established link <%s> on network plane %c\n", 146 l_ptr->name, l_ptr->b_ptr->net_plane); 147 148 if (!active[0]) { 149 active[0] = active[1] = l_ptr; 150 node_established_contact(n_ptr); 151 return; 152 } 153 if (l_ptr->priority < active[0]->priority) { 154 info("New link <%s> becomes standby\n", l_ptr->name); 155 return; 156 } 157 tipc_link_send_duplicate(active[0], l_ptr); 158 if (l_ptr->priority == active[0]->priority) { 159 active[0] = l_ptr; 160 return; 161 } 162 info("Old link <%s> becomes standby\n", active[0]->name); 163 if (active[1] != active[0]) 164 info("Old link <%s> becomes standby\n", active[1]->name); 165 active[0] = active[1] = l_ptr; 166 } 167 168 /** 169 * node_select_active_links - select active link 170 */ 171 172 static void node_select_active_links(struct tipc_node *n_ptr) 173 { 174 struct link **active = &n_ptr->active_links[0]; 175 u32 i; 176 u32 highest_prio = 0; 177 178 active[0] = active[1] = NULL; 179 180 for (i = 0; i < MAX_BEARERS; i++) { 181 struct link *l_ptr = n_ptr->links[i]; 182 183 if (!l_ptr || !tipc_link_is_up(l_ptr) || 184 (l_ptr->priority < highest_prio)) 185 continue; 186 187 if (l_ptr->priority > highest_prio) { 188 highest_prio = l_ptr->priority; 189 active[0] = active[1] = l_ptr; 190 } else { 191 active[1] = l_ptr; 192 } 193 } 194 } 195 196 /** 197 * tipc_node_link_down - handle loss of link 198 */ 199 200 void tipc_node_link_down(struct tipc_node *n_ptr, struct link *l_ptr) 201 { 202 struct link **active; 203 204 n_ptr->working_links--; 205 206 if (!tipc_link_is_active(l_ptr)) { 207 info("Lost standby link <%s> on network plane %c\n", 208 l_ptr->name, l_ptr->b_ptr->net_plane); 209 return; 210 } 211 info("Lost link <%s> on network plane %c\n", 212 l_ptr->name, l_ptr->b_ptr->net_plane); 213 214 active = &n_ptr->active_links[0]; 215 if (active[0] == l_ptr) 216 active[0] = active[1]; 217 if (active[1] == l_ptr) 218 active[1] = active[0]; 219 if (active[0] == l_ptr) 220 node_select_active_links(n_ptr); 221 if (tipc_node_is_up(n_ptr)) 222 tipc_link_changeover(l_ptr); 223 else 224 node_lost_contact(n_ptr); 225 } 226 227 int tipc_node_active_links(struct tipc_node *n_ptr) 228 { 229 return n_ptr->active_links[0] != NULL; 230 } 231 232 int tipc_node_redundant_links(struct tipc_node *n_ptr) 233 { 234 return n_ptr->working_links > 1; 235 } 236 237 int tipc_node_is_up(struct tipc_node *n_ptr) 238 { 239 return tipc_node_active_links(n_ptr); 240 } 241 242 void tipc_node_attach_link(struct tipc_node *n_ptr, struct link *l_ptr) 243 { 244 n_ptr->links[l_ptr->b_ptr->identity] = l_ptr; 245 atomic_inc(&tipc_num_links); 246 n_ptr->link_cnt++; 247 } 248 249 void tipc_node_detach_link(struct tipc_node *n_ptr, struct link *l_ptr) 250 { 251 n_ptr->links[l_ptr->b_ptr->identity] = NULL; 252 atomic_dec(&tipc_num_links); 253 n_ptr->link_cnt--; 254 } 255 256 /* 257 * Routing table management - five cases to handle: 258 * 259 * 1: A link towards a zone/cluster external node comes up. 260 * => Send a multicast message updating routing tables of all 261 * system nodes within own cluster that the new destination 262 * can be reached via this node. 263 * (node.establishedContact()=>cluster.multicastNewRoute()) 264 * 265 * 2: A link towards a slave node comes up. 266 * => Send a multicast message updating routing tables of all 267 * system nodes within own cluster that the new destination 268 * can be reached via this node. 269 * (node.establishedContact()=>cluster.multicastNewRoute()) 270 * => Send a message to the slave node about existence 271 * of all system nodes within cluster: 272 * (node.establishedContact()=>cluster.sendLocalRoutes()) 273 * 274 * 3: A new cluster local system node becomes available. 275 * => Send message(s) to this particular node containing 276 * information about all cluster external and slave 277 * nodes which can be reached via this node. 278 * (node.establishedContact()==>network.sendExternalRoutes()) 279 * (node.establishedContact()==>network.sendSlaveRoutes()) 280 * => Send messages to all directly connected slave nodes 281 * containing information about the existence of the new node 282 * (node.establishedContact()=>cluster.multicastNewRoute()) 283 * 284 * 4: The link towards a zone/cluster external node or slave 285 * node goes down. 286 * => Send a multcast message updating routing tables of all 287 * nodes within cluster that the new destination can not any 288 * longer be reached via this node. 289 * (node.lostAllLinks()=>cluster.bcastLostRoute()) 290 * 291 * 5: A cluster local system node becomes unavailable. 292 * => Remove all references to this node from the local 293 * routing tables. Note: This is a completely node 294 * local operation. 295 * (node.lostAllLinks()=>network.removeAsRouter()) 296 * => Send messages to all directly connected slave nodes 297 * containing information about loss of the node 298 * (node.establishedContact()=>cluster.multicastLostRoute()) 299 * 300 */ 301 302 static void node_established_contact(struct tipc_node *n_ptr) 303 { 304 tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr); 305 306 /* Syncronize broadcast acks */ 307 n_ptr->bclink.acked = tipc_bclink_get_last_sent(); 308 309 if (n_ptr->bclink.supported) { 310 tipc_nmap_add(&tipc_bcast_nmap, n_ptr->addr); 311 if (n_ptr->addr < tipc_own_addr) 312 tipc_own_tag++; 313 } 314 } 315 316 static void node_name_purge_complete(unsigned long node_addr) 317 { 318 struct tipc_node *n_ptr; 319 320 read_lock_bh(&tipc_net_lock); 321 n_ptr = tipc_node_find(node_addr); 322 if (n_ptr) { 323 tipc_node_lock(n_ptr); 324 n_ptr->block_setup &= ~WAIT_NAMES_GONE; 325 tipc_node_unlock(n_ptr); 326 } 327 read_unlock_bh(&tipc_net_lock); 328 } 329 330 static void node_lost_contact(struct tipc_node *n_ptr) 331 { 332 char addr_string[16]; 333 u32 i; 334 335 info("Lost contact with %s\n", 336 tipc_addr_string_fill(addr_string, n_ptr->addr)); 337 338 /* Flush broadcast link info associated with lost node */ 339 340 if (n_ptr->bclink.supported) { 341 n_ptr->bclink.gap_after = n_ptr->bclink.gap_to = 0; 342 while (n_ptr->bclink.deferred_head) { 343 struct sk_buff *buf = n_ptr->bclink.deferred_head; 344 n_ptr->bclink.deferred_head = buf->next; 345 buf_discard(buf); 346 } 347 348 if (n_ptr->bclink.defragm) { 349 buf_discard(n_ptr->bclink.defragm); 350 n_ptr->bclink.defragm = NULL; 351 } 352 353 tipc_nmap_remove(&tipc_bcast_nmap, n_ptr->addr); 354 tipc_bclink_acknowledge(n_ptr, 355 mod(n_ptr->bclink.acked + 10000)); 356 if (n_ptr->addr < tipc_own_addr) 357 tipc_own_tag--; 358 359 n_ptr->bclink.supported = 0; 360 } 361 362 /* Abort link changeover */ 363 for (i = 0; i < MAX_BEARERS; i++) { 364 struct link *l_ptr = n_ptr->links[i]; 365 if (!l_ptr) 366 continue; 367 l_ptr->reset_checkpoint = l_ptr->next_in_no; 368 l_ptr->exp_msg_count = 0; 369 tipc_link_reset_fragments(l_ptr); 370 } 371 372 /* Notify subscribers */ 373 tipc_nodesub_notify(n_ptr); 374 375 /* Prevent re-contact with node until cleanup is done */ 376 377 n_ptr->block_setup = WAIT_PEER_DOWN | WAIT_NAMES_GONE; 378 tipc_k_signal((Handler)node_name_purge_complete, n_ptr->addr); 379 } 380 381 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space) 382 { 383 u32 domain; 384 struct sk_buff *buf; 385 struct tipc_node *n_ptr; 386 struct tipc_node_info node_info; 387 u32 payload_size; 388 389 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR)) 390 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); 391 392 domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area)); 393 if (!tipc_addr_domain_valid(domain)) 394 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE 395 " (network address)"); 396 397 read_lock_bh(&tipc_net_lock); 398 if (!tipc_num_nodes) { 399 read_unlock_bh(&tipc_net_lock); 400 return tipc_cfg_reply_none(); 401 } 402 403 /* For now, get space for all other nodes */ 404 405 payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes; 406 if (payload_size > 32768u) { 407 read_unlock_bh(&tipc_net_lock); 408 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED 409 " (too many nodes)"); 410 } 411 buf = tipc_cfg_reply_alloc(payload_size); 412 if (!buf) { 413 read_unlock_bh(&tipc_net_lock); 414 return NULL; 415 } 416 417 /* Add TLVs for all nodes in scope */ 418 419 list_for_each_entry(n_ptr, &tipc_node_list, list) { 420 if (!tipc_in_scope(domain, n_ptr->addr)) 421 continue; 422 node_info.addr = htonl(n_ptr->addr); 423 node_info.up = htonl(tipc_node_is_up(n_ptr)); 424 tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO, 425 &node_info, sizeof(node_info)); 426 } 427 428 read_unlock_bh(&tipc_net_lock); 429 return buf; 430 } 431 432 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space) 433 { 434 u32 domain; 435 struct sk_buff *buf; 436 struct tipc_node *n_ptr; 437 struct tipc_link_info link_info; 438 u32 payload_size; 439 440 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR)) 441 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); 442 443 domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area)); 444 if (!tipc_addr_domain_valid(domain)) 445 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE 446 " (network address)"); 447 448 if (tipc_mode != TIPC_NET_MODE) 449 return tipc_cfg_reply_none(); 450 451 read_lock_bh(&tipc_net_lock); 452 453 /* Get space for all unicast links + multicast link */ 454 455 payload_size = TLV_SPACE(sizeof(link_info)) * 456 (atomic_read(&tipc_num_links) + 1); 457 if (payload_size > 32768u) { 458 read_unlock_bh(&tipc_net_lock); 459 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED 460 " (too many links)"); 461 } 462 buf = tipc_cfg_reply_alloc(payload_size); 463 if (!buf) { 464 read_unlock_bh(&tipc_net_lock); 465 return NULL; 466 } 467 468 /* Add TLV for broadcast link */ 469 470 link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr)); 471 link_info.up = htonl(1); 472 strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME); 473 tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info)); 474 475 /* Add TLVs for any other links in scope */ 476 477 list_for_each_entry(n_ptr, &tipc_node_list, list) { 478 u32 i; 479 480 if (!tipc_in_scope(domain, n_ptr->addr)) 481 continue; 482 tipc_node_lock(n_ptr); 483 for (i = 0; i < MAX_BEARERS; i++) { 484 if (!n_ptr->links[i]) 485 continue; 486 link_info.dest = htonl(n_ptr->addr); 487 link_info.up = htonl(tipc_link_is_up(n_ptr->links[i])); 488 strcpy(link_info.str, n_ptr->links[i]->name); 489 tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, 490 &link_info, sizeof(link_info)); 491 } 492 tipc_node_unlock(n_ptr); 493 } 494 495 read_unlock_bh(&tipc_net_lock); 496 return buf; 497 } 498