1 /* 2 * net/tipc/node.c: TIPC node management routines 3 * 4 * Copyright (c) 2000-2006, 2012-2014, Ericsson AB 5 * Copyright (c) 2005-2006, 2010-2014, 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 "link.h" 39 #include "node.h" 40 #include "name_distr.h" 41 #include "socket.h" 42 43 static void node_lost_contact(struct tipc_node *n_ptr); 44 static void node_established_contact(struct tipc_node *n_ptr); 45 46 struct tipc_sock_conn { 47 u32 port; 48 u32 peer_port; 49 u32 peer_node; 50 struct list_head list; 51 }; 52 53 static const struct nla_policy tipc_nl_node_policy[TIPC_NLA_NODE_MAX + 1] = { 54 [TIPC_NLA_NODE_UNSPEC] = { .type = NLA_UNSPEC }, 55 [TIPC_NLA_NODE_ADDR] = { .type = NLA_U32 }, 56 [TIPC_NLA_NODE_UP] = { .type = NLA_FLAG } 57 }; 58 59 /* 60 * A trivial power-of-two bitmask technique is used for speed, since this 61 * operation is done for every incoming TIPC packet. The number of hash table 62 * entries has been chosen so that no hash chain exceeds 8 nodes and will 63 * usually be much smaller (typically only a single node). 64 */ 65 static unsigned int tipc_hashfn(u32 addr) 66 { 67 return addr & (NODE_HTABLE_SIZE - 1); 68 } 69 70 /* 71 * tipc_node_find - locate specified node object, if it exists 72 */ 73 struct tipc_node *tipc_node_find(struct net *net, u32 addr) 74 { 75 struct tipc_net *tn = net_generic(net, tipc_net_id); 76 struct tipc_node *node; 77 78 if (unlikely(!in_own_cluster_exact(net, addr))) 79 return NULL; 80 81 rcu_read_lock(); 82 hlist_for_each_entry_rcu(node, &tn->node_htable[tipc_hashfn(addr)], 83 hash) { 84 if (node->addr == addr) { 85 rcu_read_unlock(); 86 return node; 87 } 88 } 89 rcu_read_unlock(); 90 return NULL; 91 } 92 93 struct tipc_node *tipc_node_create(struct net *net, u32 addr) 94 { 95 struct tipc_net *tn = net_generic(net, tipc_net_id); 96 struct tipc_node *n_ptr, *temp_node; 97 98 spin_lock_bh(&tn->node_list_lock); 99 n_ptr = tipc_node_find(net, addr); 100 if (n_ptr) 101 goto exit; 102 n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC); 103 if (!n_ptr) { 104 pr_warn("Node creation failed, no memory\n"); 105 goto exit; 106 } 107 n_ptr->addr = addr; 108 n_ptr->net = net; 109 spin_lock_init(&n_ptr->lock); 110 INIT_HLIST_NODE(&n_ptr->hash); 111 INIT_LIST_HEAD(&n_ptr->list); 112 INIT_LIST_HEAD(&n_ptr->publ_list); 113 INIT_LIST_HEAD(&n_ptr->conn_sks); 114 __skb_queue_head_init(&n_ptr->bclink.deferred_queue); 115 hlist_add_head_rcu(&n_ptr->hash, &tn->node_htable[tipc_hashfn(addr)]); 116 list_for_each_entry_rcu(temp_node, &tn->node_list, list) { 117 if (n_ptr->addr < temp_node->addr) 118 break; 119 } 120 list_add_tail_rcu(&n_ptr->list, &temp_node->list); 121 n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN; 122 n_ptr->signature = INVALID_NODE_SIG; 123 exit: 124 spin_unlock_bh(&tn->node_list_lock); 125 return n_ptr; 126 } 127 128 static void tipc_node_delete(struct tipc_net *tn, struct tipc_node *n_ptr) 129 { 130 list_del_rcu(&n_ptr->list); 131 hlist_del_rcu(&n_ptr->hash); 132 kfree_rcu(n_ptr, rcu); 133 } 134 135 void tipc_node_stop(struct net *net) 136 { 137 struct tipc_net *tn = net_generic(net, tipc_net_id); 138 struct tipc_node *node, *t_node; 139 140 spin_lock_bh(&tn->node_list_lock); 141 list_for_each_entry_safe(node, t_node, &tn->node_list, list) 142 tipc_node_delete(tn, node); 143 spin_unlock_bh(&tn->node_list_lock); 144 } 145 146 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port) 147 { 148 struct tipc_node *node; 149 struct tipc_sock_conn *conn; 150 151 if (in_own_node(net, dnode)) 152 return 0; 153 154 node = tipc_node_find(net, dnode); 155 if (!node) { 156 pr_warn("Connecting sock to node 0x%x failed\n", dnode); 157 return -EHOSTUNREACH; 158 } 159 conn = kmalloc(sizeof(*conn), GFP_ATOMIC); 160 if (!conn) 161 return -EHOSTUNREACH; 162 conn->peer_node = dnode; 163 conn->port = port; 164 conn->peer_port = peer_port; 165 166 tipc_node_lock(node); 167 list_add_tail(&conn->list, &node->conn_sks); 168 tipc_node_unlock(node); 169 return 0; 170 } 171 172 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port) 173 { 174 struct tipc_node *node; 175 struct tipc_sock_conn *conn, *safe; 176 177 if (in_own_node(net, dnode)) 178 return; 179 180 node = tipc_node_find(net, dnode); 181 if (!node) 182 return; 183 184 tipc_node_lock(node); 185 list_for_each_entry_safe(conn, safe, &node->conn_sks, list) { 186 if (port != conn->port) 187 continue; 188 list_del(&conn->list); 189 kfree(conn); 190 } 191 tipc_node_unlock(node); 192 } 193 194 /** 195 * tipc_node_link_up - handle addition of link 196 * 197 * Link becomes active (alone or shared) or standby, depending on its priority. 198 */ 199 void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 200 { 201 struct tipc_link **active = &n_ptr->active_links[0]; 202 203 n_ptr->working_links++; 204 n_ptr->action_flags |= TIPC_NOTIFY_LINK_UP; 205 n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id; 206 207 pr_debug("Established link <%s> on network plane %c\n", 208 l_ptr->name, l_ptr->net_plane); 209 210 if (!active[0]) { 211 active[0] = active[1] = l_ptr; 212 node_established_contact(n_ptr); 213 goto exit; 214 } 215 if (l_ptr->priority < active[0]->priority) { 216 pr_debug("New link <%s> becomes standby\n", l_ptr->name); 217 goto exit; 218 } 219 tipc_link_dup_queue_xmit(active[0], l_ptr); 220 if (l_ptr->priority == active[0]->priority) { 221 active[0] = l_ptr; 222 goto exit; 223 } 224 pr_debug("Old link <%s> becomes standby\n", active[0]->name); 225 if (active[1] != active[0]) 226 pr_debug("Old link <%s> becomes standby\n", active[1]->name); 227 active[0] = active[1] = l_ptr; 228 exit: 229 /* Leave room for changeover header when returning 'mtu' to users: */ 230 n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE; 231 n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE; 232 } 233 234 /** 235 * node_select_active_links - select active link 236 */ 237 static void node_select_active_links(struct tipc_node *n_ptr) 238 { 239 struct tipc_link **active = &n_ptr->active_links[0]; 240 u32 i; 241 u32 highest_prio = 0; 242 243 active[0] = active[1] = NULL; 244 245 for (i = 0; i < MAX_BEARERS; i++) { 246 struct tipc_link *l_ptr = n_ptr->links[i]; 247 248 if (!l_ptr || !tipc_link_is_up(l_ptr) || 249 (l_ptr->priority < highest_prio)) 250 continue; 251 252 if (l_ptr->priority > highest_prio) { 253 highest_prio = l_ptr->priority; 254 active[0] = active[1] = l_ptr; 255 } else { 256 active[1] = l_ptr; 257 } 258 } 259 } 260 261 /** 262 * tipc_node_link_down - handle loss of link 263 */ 264 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 265 { 266 struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id); 267 struct tipc_link **active; 268 269 n_ptr->working_links--; 270 n_ptr->action_flags |= TIPC_NOTIFY_LINK_DOWN; 271 n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id; 272 273 if (!tipc_link_is_active(l_ptr)) { 274 pr_debug("Lost standby link <%s> on network plane %c\n", 275 l_ptr->name, l_ptr->net_plane); 276 return; 277 } 278 pr_debug("Lost link <%s> on network plane %c\n", 279 l_ptr->name, l_ptr->net_plane); 280 281 active = &n_ptr->active_links[0]; 282 if (active[0] == l_ptr) 283 active[0] = active[1]; 284 if (active[1] == l_ptr) 285 active[1] = active[0]; 286 if (active[0] == l_ptr) 287 node_select_active_links(n_ptr); 288 if (tipc_node_is_up(n_ptr)) 289 tipc_link_failover_send_queue(l_ptr); 290 else 291 node_lost_contact(n_ptr); 292 293 /* Leave room for changeover header when returning 'mtu' to users: */ 294 if (active[0]) { 295 n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE; 296 n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE; 297 return; 298 } 299 300 /* Loopback link went down? No fragmentation needed from now on. */ 301 if (n_ptr->addr == tn->own_addr) { 302 n_ptr->act_mtus[0] = MAX_MSG_SIZE; 303 n_ptr->act_mtus[1] = MAX_MSG_SIZE; 304 } 305 } 306 307 int tipc_node_active_links(struct tipc_node *n_ptr) 308 { 309 return n_ptr->active_links[0] != NULL; 310 } 311 312 int tipc_node_is_up(struct tipc_node *n_ptr) 313 { 314 return tipc_node_active_links(n_ptr); 315 } 316 317 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 318 { 319 n_ptr->links[l_ptr->bearer_id] = l_ptr; 320 n_ptr->link_cnt++; 321 } 322 323 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 324 { 325 int i; 326 327 for (i = 0; i < MAX_BEARERS; i++) { 328 if (l_ptr != n_ptr->links[i]) 329 continue; 330 n_ptr->links[i] = NULL; 331 n_ptr->link_cnt--; 332 } 333 } 334 335 static void node_established_contact(struct tipc_node *n_ptr) 336 { 337 n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP; 338 n_ptr->bclink.oos_state = 0; 339 n_ptr->bclink.acked = tipc_bclink_get_last_sent(n_ptr->net); 340 tipc_bclink_add_node(n_ptr->net, n_ptr->addr); 341 } 342 343 static void node_lost_contact(struct tipc_node *n_ptr) 344 { 345 char addr_string[16]; 346 struct tipc_sock_conn *conn, *safe; 347 struct list_head *conns = &n_ptr->conn_sks; 348 struct sk_buff *skb; 349 struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id); 350 uint i; 351 352 pr_debug("Lost contact with %s\n", 353 tipc_addr_string_fill(addr_string, n_ptr->addr)); 354 355 /* Flush broadcast link info associated with lost node */ 356 if (n_ptr->bclink.recv_permitted) { 357 __skb_queue_purge(&n_ptr->bclink.deferred_queue); 358 359 if (n_ptr->bclink.reasm_buf) { 360 kfree_skb(n_ptr->bclink.reasm_buf); 361 n_ptr->bclink.reasm_buf = NULL; 362 } 363 364 tipc_bclink_remove_node(n_ptr->net, n_ptr->addr); 365 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ); 366 367 n_ptr->bclink.recv_permitted = false; 368 } 369 370 /* Abort link changeover */ 371 for (i = 0; i < MAX_BEARERS; i++) { 372 struct tipc_link *l_ptr = n_ptr->links[i]; 373 if (!l_ptr) 374 continue; 375 l_ptr->reset_checkpoint = l_ptr->next_in_no; 376 l_ptr->exp_msg_count = 0; 377 tipc_link_reset_fragments(l_ptr); 378 379 /* Link marked for deletion after failover? => do it now */ 380 if (l_ptr->flags & LINK_STOPPED) 381 tipc_link_delete(l_ptr); 382 } 383 384 n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN; 385 386 /* Prevent re-contact with node until cleanup is done */ 387 n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN; 388 389 /* Notify publications from this node */ 390 n_ptr->action_flags |= TIPC_NOTIFY_NODE_DOWN; 391 392 /* Notify sockets connected to node */ 393 list_for_each_entry_safe(conn, safe, conns, list) { 394 skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG, 395 SHORT_H_SIZE, 0, tn->own_addr, 396 conn->peer_node, conn->port, 397 conn->peer_port, TIPC_ERR_NO_NODE); 398 if (likely(skb)) { 399 skb_queue_tail(n_ptr->inputq, skb); 400 n_ptr->action_flags |= TIPC_MSG_EVT; 401 } 402 list_del(&conn->list); 403 kfree(conn); 404 } 405 } 406 407 /** 408 * tipc_node_get_linkname - get the name of a link 409 * 410 * @bearer_id: id of the bearer 411 * @node: peer node address 412 * @linkname: link name output buffer 413 * 414 * Returns 0 on success 415 */ 416 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr, 417 char *linkname, size_t len) 418 { 419 struct tipc_link *link; 420 struct tipc_node *node = tipc_node_find(net, addr); 421 422 if ((bearer_id >= MAX_BEARERS) || !node) 423 return -EINVAL; 424 tipc_node_lock(node); 425 link = node->links[bearer_id]; 426 if (link) { 427 strncpy(linkname, link->name, len); 428 tipc_node_unlock(node); 429 return 0; 430 } 431 tipc_node_unlock(node); 432 return -EINVAL; 433 } 434 435 void tipc_node_unlock(struct tipc_node *node) 436 { 437 struct net *net = node->net; 438 u32 addr = 0; 439 u32 flags = node->action_flags; 440 u32 link_id = 0; 441 struct list_head *publ_list; 442 struct sk_buff_head *inputq = node->inputq; 443 struct sk_buff_head *namedq; 444 445 if (likely(!flags || (flags == TIPC_MSG_EVT))) { 446 node->action_flags = 0; 447 spin_unlock_bh(&node->lock); 448 if (flags == TIPC_MSG_EVT) 449 tipc_sk_rcv(net, inputq); 450 return; 451 } 452 453 addr = node->addr; 454 link_id = node->link_id; 455 namedq = node->namedq; 456 publ_list = &node->publ_list; 457 458 node->action_flags &= ~(TIPC_MSG_EVT | 459 TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP | 460 TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP | 461 TIPC_WAKEUP_BCAST_USERS | TIPC_BCAST_MSG_EVT | 462 TIPC_NAMED_MSG_EVT); 463 464 spin_unlock_bh(&node->lock); 465 466 if (flags & TIPC_NOTIFY_NODE_DOWN) 467 tipc_publ_notify(net, publ_list, addr); 468 469 if (flags & TIPC_WAKEUP_BCAST_USERS) 470 tipc_bclink_wakeup_users(net); 471 472 if (flags & TIPC_NOTIFY_NODE_UP) 473 tipc_named_node_up(net, addr); 474 475 if (flags & TIPC_NOTIFY_LINK_UP) 476 tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr, 477 TIPC_NODE_SCOPE, link_id, addr); 478 479 if (flags & TIPC_NOTIFY_LINK_DOWN) 480 tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr, 481 link_id, addr); 482 483 if (flags & TIPC_MSG_EVT) 484 tipc_sk_rcv(net, inputq); 485 486 if (flags & TIPC_NAMED_MSG_EVT) 487 tipc_named_rcv(net, namedq); 488 489 if (flags & TIPC_BCAST_MSG_EVT) 490 tipc_bclink_input(net); 491 } 492 493 /* Caller should hold node lock for the passed node */ 494 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node) 495 { 496 void *hdr; 497 struct nlattr *attrs; 498 499 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, 500 NLM_F_MULTI, TIPC_NL_NODE_GET); 501 if (!hdr) 502 return -EMSGSIZE; 503 504 attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE); 505 if (!attrs) 506 goto msg_full; 507 508 if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr)) 509 goto attr_msg_full; 510 if (tipc_node_is_up(node)) 511 if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP)) 512 goto attr_msg_full; 513 514 nla_nest_end(msg->skb, attrs); 515 genlmsg_end(msg->skb, hdr); 516 517 return 0; 518 519 attr_msg_full: 520 nla_nest_cancel(msg->skb, attrs); 521 msg_full: 522 genlmsg_cancel(msg->skb, hdr); 523 524 return -EMSGSIZE; 525 } 526 527 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb) 528 { 529 int err; 530 struct net *net = sock_net(skb->sk); 531 struct tipc_net *tn = net_generic(net, tipc_net_id); 532 int done = cb->args[0]; 533 int last_addr = cb->args[1]; 534 struct tipc_node *node; 535 struct tipc_nl_msg msg; 536 537 if (done) 538 return 0; 539 540 msg.skb = skb; 541 msg.portid = NETLINK_CB(cb->skb).portid; 542 msg.seq = cb->nlh->nlmsg_seq; 543 544 rcu_read_lock(); 545 546 if (last_addr && !tipc_node_find(net, last_addr)) { 547 rcu_read_unlock(); 548 /* We never set seq or call nl_dump_check_consistent() this 549 * means that setting prev_seq here will cause the consistence 550 * check to fail in the netlink callback handler. Resulting in 551 * the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if 552 * the node state changed while we released the lock. 553 */ 554 cb->prev_seq = 1; 555 return -EPIPE; 556 } 557 558 list_for_each_entry_rcu(node, &tn->node_list, list) { 559 if (last_addr) { 560 if (node->addr == last_addr) 561 last_addr = 0; 562 else 563 continue; 564 } 565 566 tipc_node_lock(node); 567 err = __tipc_nl_add_node(&msg, node); 568 if (err) { 569 last_addr = node->addr; 570 tipc_node_unlock(node); 571 goto out; 572 } 573 574 tipc_node_unlock(node); 575 } 576 done = 1; 577 out: 578 cb->args[0] = done; 579 cb->args[1] = last_addr; 580 rcu_read_unlock(); 581 582 return skb->len; 583 } 584