node.c revision a635b46bd884efc1fc98819cb5a200da255d575c
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 inline 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 70struct tipc_node *tipc_node_find(u32 addr) 71{ 72 struct tipc_node *node; 73 struct hlist_node *pos; 74 75 if (unlikely(!in_own_cluster(addr))) 76 return NULL; 77 78 hlist_for_each_entry(node, pos, &node_htable[tipc_hashfn(addr)], hash) { 79 if (node->addr == addr) 80 return node; 81 } 82 return NULL; 83} 84 85/** 86 * tipc_node_create - create neighboring node 87 * 88 * Currently, this routine is called by neighbor discovery code, which holds 89 * net_lock for reading only. We must take node_create_lock to ensure a node 90 * isn't created twice if two different bearers discover the node at the same 91 * time. (It would be preferable to switch to holding net_lock in write mode, 92 * but this is a non-trivial change.) 93 */ 94 95struct tipc_node *tipc_node_create(u32 addr) 96{ 97 struct tipc_node *n_ptr, *temp_node; 98 99 spin_lock_bh(&node_create_lock); 100 101 n_ptr = tipc_node_find(addr); 102 if (n_ptr) { 103 spin_unlock_bh(&node_create_lock); 104 return n_ptr; 105 } 106 107 n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC); 108 if (!n_ptr) { 109 spin_unlock_bh(&node_create_lock); 110 warn("Node creation failed, no memory\n"); 111 return NULL; 112 } 113 114 n_ptr->addr = addr; 115 spin_lock_init(&n_ptr->lock); 116 INIT_HLIST_NODE(&n_ptr->hash); 117 INIT_LIST_HEAD(&n_ptr->list); 118 INIT_LIST_HEAD(&n_ptr->nsub); 119 120 hlist_add_head(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]); 121 122 list_for_each_entry(temp_node, &tipc_node_list, list) { 123 if (n_ptr->addr < temp_node->addr) 124 break; 125 } 126 list_add_tail(&n_ptr->list, &temp_node->list); 127 n_ptr->block_setup = WAIT_PEER_DOWN; 128 n_ptr->signature = INVALID_NODE_SIG; 129 130 tipc_num_nodes++; 131 132 spin_unlock_bh(&node_create_lock); 133 return n_ptr; 134} 135 136void tipc_node_delete(struct tipc_node *n_ptr) 137{ 138 list_del(&n_ptr->list); 139 hlist_del(&n_ptr->hash); 140 kfree(n_ptr); 141 142 tipc_num_nodes--; 143} 144 145 146/** 147 * tipc_node_link_up - handle addition of link 148 * 149 * Link becomes active (alone or shared) or standby, depending on its priority. 150 */ 151 152void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 153{ 154 struct tipc_link **active = &n_ptr->active_links[0]; 155 156 n_ptr->working_links++; 157 158 info("Established link <%s> on network plane %c\n", 159 l_ptr->name, l_ptr->b_ptr->net_plane); 160 161 if (!active[0]) { 162 active[0] = active[1] = l_ptr; 163 node_established_contact(n_ptr); 164 return; 165 } 166 if (l_ptr->priority < active[0]->priority) { 167 info("New link <%s> becomes standby\n", l_ptr->name); 168 return; 169 } 170 tipc_link_send_duplicate(active[0], l_ptr); 171 if (l_ptr->priority == active[0]->priority) { 172 active[0] = l_ptr; 173 return; 174 } 175 info("Old link <%s> becomes standby\n", active[0]->name); 176 if (active[1] != active[0]) 177 info("Old link <%s> becomes standby\n", active[1]->name); 178 active[0] = active[1] = l_ptr; 179} 180 181/** 182 * node_select_active_links - select active link 183 */ 184 185static void node_select_active_links(struct tipc_node *n_ptr) 186{ 187 struct tipc_link **active = &n_ptr->active_links[0]; 188 u32 i; 189 u32 highest_prio = 0; 190 191 active[0] = active[1] = NULL; 192 193 for (i = 0; i < MAX_BEARERS; i++) { 194 struct tipc_link *l_ptr = n_ptr->links[i]; 195 196 if (!l_ptr || !tipc_link_is_up(l_ptr) || 197 (l_ptr->priority < highest_prio)) 198 continue; 199 200 if (l_ptr->priority > highest_prio) { 201 highest_prio = l_ptr->priority; 202 active[0] = active[1] = l_ptr; 203 } else { 204 active[1] = l_ptr; 205 } 206 } 207} 208 209/** 210 * tipc_node_link_down - handle loss of link 211 */ 212 213void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 214{ 215 struct tipc_link **active; 216 217 n_ptr->working_links--; 218 219 if (!tipc_link_is_active(l_ptr)) { 220 info("Lost standby link <%s> on network plane %c\n", 221 l_ptr->name, l_ptr->b_ptr->net_plane); 222 return; 223 } 224 info("Lost link <%s> on network plane %c\n", 225 l_ptr->name, l_ptr->b_ptr->net_plane); 226 227 active = &n_ptr->active_links[0]; 228 if (active[0] == l_ptr) 229 active[0] = active[1]; 230 if (active[1] == l_ptr) 231 active[1] = active[0]; 232 if (active[0] == l_ptr) 233 node_select_active_links(n_ptr); 234 if (tipc_node_is_up(n_ptr)) 235 tipc_link_changeover(l_ptr); 236 else 237 node_lost_contact(n_ptr); 238} 239 240int tipc_node_active_links(struct tipc_node *n_ptr) 241{ 242 return n_ptr->active_links[0] != NULL; 243} 244 245int tipc_node_redundant_links(struct tipc_node *n_ptr) 246{ 247 return n_ptr->working_links > 1; 248} 249 250int tipc_node_is_up(struct tipc_node *n_ptr) 251{ 252 return tipc_node_active_links(n_ptr); 253} 254 255void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 256{ 257 n_ptr->links[l_ptr->b_ptr->identity] = l_ptr; 258 atomic_inc(&tipc_num_links); 259 n_ptr->link_cnt++; 260} 261 262void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 263{ 264 n_ptr->links[l_ptr->b_ptr->identity] = NULL; 265 atomic_dec(&tipc_num_links); 266 n_ptr->link_cnt--; 267} 268 269/* 270 * Routing table management - five cases to handle: 271 * 272 * 1: A link towards a zone/cluster external node comes up. 273 * => Send a multicast message updating routing tables of all 274 * system nodes within own cluster that the new destination 275 * can be reached via this node. 276 * (node.establishedContact()=>cluster.multicastNewRoute()) 277 * 278 * 2: A link towards a slave node comes up. 279 * => Send a multicast message updating routing tables of all 280 * system nodes within own cluster that the new destination 281 * can be reached via this node. 282 * (node.establishedContact()=>cluster.multicastNewRoute()) 283 * => Send a message to the slave node about existence 284 * of all system nodes within cluster: 285 * (node.establishedContact()=>cluster.sendLocalRoutes()) 286 * 287 * 3: A new cluster local system node becomes available. 288 * => Send message(s) to this particular node containing 289 * information about all cluster external and slave 290 * nodes which can be reached via this node. 291 * (node.establishedContact()==>network.sendExternalRoutes()) 292 * (node.establishedContact()==>network.sendSlaveRoutes()) 293 * => Send messages to all directly connected slave nodes 294 * containing information about the existence of the new node 295 * (node.establishedContact()=>cluster.multicastNewRoute()) 296 * 297 * 4: The link towards a zone/cluster external node or slave 298 * node goes down. 299 * => Send a multcast message updating routing tables of all 300 * nodes within cluster that the new destination can not any 301 * longer be reached via this node. 302 * (node.lostAllLinks()=>cluster.bcastLostRoute()) 303 * 304 * 5: A cluster local system node becomes unavailable. 305 * => Remove all references to this node from the local 306 * routing tables. Note: This is a completely node 307 * local operation. 308 * (node.lostAllLinks()=>network.removeAsRouter()) 309 * => Send messages to all directly connected slave nodes 310 * containing information about loss of the node 311 * (node.establishedContact()=>cluster.multicastLostRoute()) 312 * 313 */ 314 315static void node_established_contact(struct tipc_node *n_ptr) 316{ 317 tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr); 318 319 /* Syncronize broadcast acks */ 320 n_ptr->bclink.acked = tipc_bclink_get_last_sent(); 321 322 if (n_ptr->bclink.supportable) { 323 tipc_bclink_add_node(n_ptr->addr); 324 n_ptr->bclink.supported = 1; 325 } 326} 327 328static void node_name_purge_complete(unsigned long node_addr) 329{ 330 struct tipc_node *n_ptr; 331 332 read_lock_bh(&tipc_net_lock); 333 n_ptr = tipc_node_find(node_addr); 334 if (n_ptr) { 335 tipc_node_lock(n_ptr); 336 n_ptr->block_setup &= ~WAIT_NAMES_GONE; 337 tipc_node_unlock(n_ptr); 338 } 339 read_unlock_bh(&tipc_net_lock); 340} 341 342static void node_lost_contact(struct tipc_node *n_ptr) 343{ 344 char addr_string[16]; 345 u32 i; 346 347 info("Lost contact with %s\n", 348 tipc_addr_string_fill(addr_string, n_ptr->addr)); 349 350 /* Flush broadcast link info associated with lost node */ 351 352 if (n_ptr->bclink.supported) { 353 while (n_ptr->bclink.deferred_head) { 354 struct sk_buff *buf = n_ptr->bclink.deferred_head; 355 n_ptr->bclink.deferred_head = buf->next; 356 buf_discard(buf); 357 } 358 n_ptr->bclink.deferred_size = 0; 359 360 if (n_ptr->bclink.defragm) { 361 buf_discard(n_ptr->bclink.defragm); 362 n_ptr->bclink.defragm = NULL; 363 } 364 365 tipc_bclink_remove_node(n_ptr->addr); 366 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ); 367 368 n_ptr->bclink.supported = 0; 369 } 370 371 /* Abort link changeover */ 372 for (i = 0; i < MAX_BEARERS; i++) { 373 struct tipc_link *l_ptr = n_ptr->links[i]; 374 if (!l_ptr) 375 continue; 376 l_ptr->reset_checkpoint = l_ptr->next_in_no; 377 l_ptr->exp_msg_count = 0; 378 tipc_link_reset_fragments(l_ptr); 379 } 380 381 /* Notify subscribers */ 382 tipc_nodesub_notify(n_ptr); 383 384 /* Prevent re-contact with node until cleanup is done */ 385 386 n_ptr->block_setup = WAIT_PEER_DOWN | WAIT_NAMES_GONE; 387 tipc_k_signal((Handler)node_name_purge_complete, n_ptr->addr); 388} 389 390struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space) 391{ 392 u32 domain; 393 struct sk_buff *buf; 394 struct tipc_node *n_ptr; 395 struct tipc_node_info node_info; 396 u32 payload_size; 397 398 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR)) 399 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); 400 401 domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area)); 402 if (!tipc_addr_domain_valid(domain)) 403 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE 404 " (network address)"); 405 406 read_lock_bh(&tipc_net_lock); 407 if (!tipc_num_nodes) { 408 read_unlock_bh(&tipc_net_lock); 409 return tipc_cfg_reply_none(); 410 } 411 412 /* For now, get space for all other nodes */ 413 414 payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes; 415 if (payload_size > 32768u) { 416 read_unlock_bh(&tipc_net_lock); 417 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED 418 " (too many nodes)"); 419 } 420 buf = tipc_cfg_reply_alloc(payload_size); 421 if (!buf) { 422 read_unlock_bh(&tipc_net_lock); 423 return NULL; 424 } 425 426 /* Add TLVs for all nodes in scope */ 427 428 list_for_each_entry(n_ptr, &tipc_node_list, list) { 429 if (!tipc_in_scope(domain, n_ptr->addr)) 430 continue; 431 node_info.addr = htonl(n_ptr->addr); 432 node_info.up = htonl(tipc_node_is_up(n_ptr)); 433 tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO, 434 &node_info, sizeof(node_info)); 435 } 436 437 read_unlock_bh(&tipc_net_lock); 438 return buf; 439} 440 441struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space) 442{ 443 u32 domain; 444 struct sk_buff *buf; 445 struct tipc_node *n_ptr; 446 struct tipc_link_info link_info; 447 u32 payload_size; 448 449 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR)) 450 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); 451 452 domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area)); 453 if (!tipc_addr_domain_valid(domain)) 454 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE 455 " (network address)"); 456 457 if (tipc_mode != TIPC_NET_MODE) 458 return tipc_cfg_reply_none(); 459 460 read_lock_bh(&tipc_net_lock); 461 462 /* Get space for all unicast links + broadcast link */ 463 464 payload_size = TLV_SPACE(sizeof(link_info)) * 465 (atomic_read(&tipc_num_links) + 1); 466 if (payload_size > 32768u) { 467 read_unlock_bh(&tipc_net_lock); 468 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED 469 " (too many links)"); 470 } 471 buf = tipc_cfg_reply_alloc(payload_size); 472 if (!buf) { 473 read_unlock_bh(&tipc_net_lock); 474 return NULL; 475 } 476 477 /* Add TLV for broadcast link */ 478 479 link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr)); 480 link_info.up = htonl(1); 481 strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME); 482 tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info)); 483 484 /* Add TLVs for any other links in scope */ 485 486 list_for_each_entry(n_ptr, &tipc_node_list, list) { 487 u32 i; 488 489 if (!tipc_in_scope(domain, n_ptr->addr)) 490 continue; 491 tipc_node_lock(n_ptr); 492 for (i = 0; i < MAX_BEARERS; i++) { 493 if (!n_ptr->links[i]) 494 continue; 495 link_info.dest = htonl(n_ptr->addr); 496 link_info.up = htonl(tipc_link_is_up(n_ptr->links[i])); 497 strcpy(link_info.str, n_ptr->links[i]->name); 498 tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, 499 &link_info, sizeof(link_info)); 500 } 501 tipc_node_unlock(n_ptr); 502 } 503 504 read_unlock_bh(&tipc_net_lock); 505 return buf; 506} 507