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 static void tipc_node_delete(struct tipc_node *node); 46 47 struct tipc_sock_conn { 48 u32 port; 49 u32 peer_port; 50 u32 peer_node; 51 struct list_head list; 52 }; 53 54 static const struct nla_policy tipc_nl_node_policy[TIPC_NLA_NODE_MAX + 1] = { 55 [TIPC_NLA_NODE_UNSPEC] = { .type = NLA_UNSPEC }, 56 [TIPC_NLA_NODE_ADDR] = { .type = NLA_U32 }, 57 [TIPC_NLA_NODE_UP] = { .type = NLA_FLAG } 58 }; 59 60 /* 61 * A trivial power-of-two bitmask technique is used for speed, since this 62 * operation is done for every incoming TIPC packet. The number of hash table 63 * entries has been chosen so that no hash chain exceeds 8 nodes and will 64 * usually be much smaller (typically only a single node). 65 */ 66 static unsigned int tipc_hashfn(u32 addr) 67 { 68 return addr & (NODE_HTABLE_SIZE - 1); 69 } 70 71 static void tipc_node_kref_release(struct kref *kref) 72 { 73 struct tipc_node *node = container_of(kref, struct tipc_node, kref); 74 75 tipc_node_delete(node); 76 } 77 78 void tipc_node_put(struct tipc_node *node) 79 { 80 kref_put(&node->kref, tipc_node_kref_release); 81 } 82 83 static void tipc_node_get(struct tipc_node *node) 84 { 85 kref_get(&node->kref); 86 } 87 88 /* 89 * tipc_node_find - locate specified node object, if it exists 90 */ 91 struct tipc_node *tipc_node_find(struct net *net, u32 addr) 92 { 93 struct tipc_net *tn = net_generic(net, tipc_net_id); 94 struct tipc_node *node; 95 96 if (unlikely(!in_own_cluster_exact(net, addr))) 97 return NULL; 98 99 rcu_read_lock(); 100 hlist_for_each_entry_rcu(node, &tn->node_htable[tipc_hashfn(addr)], 101 hash) { 102 if (node->addr == addr) { 103 tipc_node_get(node); 104 rcu_read_unlock(); 105 return node; 106 } 107 } 108 rcu_read_unlock(); 109 return NULL; 110 } 111 112 struct tipc_node *tipc_node_create(struct net *net, u32 addr) 113 { 114 struct tipc_net *tn = net_generic(net, tipc_net_id); 115 struct tipc_node *n_ptr, *temp_node; 116 117 spin_lock_bh(&tn->node_list_lock); 118 n_ptr = tipc_node_find(net, addr); 119 if (n_ptr) 120 goto exit; 121 n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC); 122 if (!n_ptr) { 123 pr_warn("Node creation failed, no memory\n"); 124 goto exit; 125 } 126 n_ptr->addr = addr; 127 n_ptr->net = net; 128 kref_init(&n_ptr->kref); 129 spin_lock_init(&n_ptr->lock); 130 INIT_HLIST_NODE(&n_ptr->hash); 131 INIT_LIST_HEAD(&n_ptr->list); 132 INIT_LIST_HEAD(&n_ptr->publ_list); 133 INIT_LIST_HEAD(&n_ptr->conn_sks); 134 __skb_queue_head_init(&n_ptr->bclink.deferdq); 135 hlist_add_head_rcu(&n_ptr->hash, &tn->node_htable[tipc_hashfn(addr)]); 136 list_for_each_entry_rcu(temp_node, &tn->node_list, list) { 137 if (n_ptr->addr < temp_node->addr) 138 break; 139 } 140 list_add_tail_rcu(&n_ptr->list, &temp_node->list); 141 n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN; 142 n_ptr->signature = INVALID_NODE_SIG; 143 tipc_node_get(n_ptr); 144 exit: 145 spin_unlock_bh(&tn->node_list_lock); 146 return n_ptr; 147 } 148 149 static void tipc_node_delete(struct tipc_node *node) 150 { 151 list_del_rcu(&node->list); 152 hlist_del_rcu(&node->hash); 153 kfree_rcu(node, rcu); 154 } 155 156 void tipc_node_stop(struct net *net) 157 { 158 struct tipc_net *tn = net_generic(net, tipc_net_id); 159 struct tipc_node *node, *t_node; 160 161 spin_lock_bh(&tn->node_list_lock); 162 list_for_each_entry_safe(node, t_node, &tn->node_list, list) 163 tipc_node_put(node); 164 spin_unlock_bh(&tn->node_list_lock); 165 } 166 167 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port) 168 { 169 struct tipc_node *node; 170 struct tipc_sock_conn *conn; 171 int err = 0; 172 173 if (in_own_node(net, dnode)) 174 return 0; 175 176 node = tipc_node_find(net, dnode); 177 if (!node) { 178 pr_warn("Connecting sock to node 0x%x failed\n", dnode); 179 return -EHOSTUNREACH; 180 } 181 conn = kmalloc(sizeof(*conn), GFP_ATOMIC); 182 if (!conn) { 183 err = -EHOSTUNREACH; 184 goto exit; 185 } 186 conn->peer_node = dnode; 187 conn->port = port; 188 conn->peer_port = peer_port; 189 190 tipc_node_lock(node); 191 list_add_tail(&conn->list, &node->conn_sks); 192 tipc_node_unlock(node); 193 exit: 194 tipc_node_put(node); 195 return err; 196 } 197 198 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port) 199 { 200 struct tipc_node *node; 201 struct tipc_sock_conn *conn, *safe; 202 203 if (in_own_node(net, dnode)) 204 return; 205 206 node = tipc_node_find(net, dnode); 207 if (!node) 208 return; 209 210 tipc_node_lock(node); 211 list_for_each_entry_safe(conn, safe, &node->conn_sks, list) { 212 if (port != conn->port) 213 continue; 214 list_del(&conn->list); 215 kfree(conn); 216 } 217 tipc_node_unlock(node); 218 tipc_node_put(node); 219 } 220 221 /** 222 * tipc_node_link_up - handle addition of link 223 * 224 * Link becomes active (alone or shared) or standby, depending on its priority. 225 */ 226 void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 227 { 228 struct tipc_link **active = &n_ptr->active_links[0]; 229 230 n_ptr->working_links++; 231 n_ptr->action_flags |= TIPC_NOTIFY_LINK_UP; 232 n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id; 233 234 pr_debug("Established link <%s> on network plane %c\n", 235 l_ptr->name, l_ptr->net_plane); 236 237 if (!active[0]) { 238 active[0] = active[1] = l_ptr; 239 node_established_contact(n_ptr); 240 goto exit; 241 } 242 if (l_ptr->priority < active[0]->priority) { 243 pr_debug("New link <%s> becomes standby\n", l_ptr->name); 244 goto exit; 245 } 246 tipc_link_dup_queue_xmit(active[0], l_ptr); 247 if (l_ptr->priority == active[0]->priority) { 248 active[0] = l_ptr; 249 goto exit; 250 } 251 pr_debug("Old link <%s> becomes standby\n", active[0]->name); 252 if (active[1] != active[0]) 253 pr_debug("Old link <%s> becomes standby\n", active[1]->name); 254 active[0] = active[1] = l_ptr; 255 exit: 256 /* Leave room for changeover header when returning 'mtu' to users: */ 257 n_ptr->act_mtus[0] = active[0]->mtu - INT_H_SIZE; 258 n_ptr->act_mtus[1] = active[1]->mtu - INT_H_SIZE; 259 } 260 261 /** 262 * node_select_active_links - select active link 263 */ 264 static void node_select_active_links(struct tipc_node *n_ptr) 265 { 266 struct tipc_link **active = &n_ptr->active_links[0]; 267 u32 i; 268 u32 highest_prio = 0; 269 270 active[0] = active[1] = NULL; 271 272 for (i = 0; i < MAX_BEARERS; i++) { 273 struct tipc_link *l_ptr = n_ptr->links[i]; 274 275 if (!l_ptr || !tipc_link_is_up(l_ptr) || 276 (l_ptr->priority < highest_prio)) 277 continue; 278 279 if (l_ptr->priority > highest_prio) { 280 highest_prio = l_ptr->priority; 281 active[0] = active[1] = l_ptr; 282 } else { 283 active[1] = l_ptr; 284 } 285 } 286 } 287 288 /** 289 * tipc_node_link_down - handle loss of link 290 */ 291 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 292 { 293 struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id); 294 struct tipc_link **active; 295 296 n_ptr->working_links--; 297 n_ptr->action_flags |= TIPC_NOTIFY_LINK_DOWN; 298 n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id; 299 300 if (!tipc_link_is_active(l_ptr)) { 301 pr_debug("Lost standby link <%s> on network plane %c\n", 302 l_ptr->name, l_ptr->net_plane); 303 return; 304 } 305 pr_debug("Lost link <%s> on network plane %c\n", 306 l_ptr->name, l_ptr->net_plane); 307 308 active = &n_ptr->active_links[0]; 309 if (active[0] == l_ptr) 310 active[0] = active[1]; 311 if (active[1] == l_ptr) 312 active[1] = active[0]; 313 if (active[0] == l_ptr) 314 node_select_active_links(n_ptr); 315 if (tipc_node_is_up(n_ptr)) 316 tipc_link_failover_send_queue(l_ptr); 317 else 318 node_lost_contact(n_ptr); 319 320 /* Leave room for changeover header when returning 'mtu' to users: */ 321 if (active[0]) { 322 n_ptr->act_mtus[0] = active[0]->mtu - INT_H_SIZE; 323 n_ptr->act_mtus[1] = active[1]->mtu - INT_H_SIZE; 324 return; 325 } 326 /* Loopback link went down? No fragmentation needed from now on. */ 327 if (n_ptr->addr == tn->own_addr) { 328 n_ptr->act_mtus[0] = MAX_MSG_SIZE; 329 n_ptr->act_mtus[1] = MAX_MSG_SIZE; 330 } 331 } 332 333 int tipc_node_active_links(struct tipc_node *n_ptr) 334 { 335 return n_ptr->active_links[0] != NULL; 336 } 337 338 int tipc_node_is_up(struct tipc_node *n_ptr) 339 { 340 return tipc_node_active_links(n_ptr); 341 } 342 343 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 344 { 345 n_ptr->links[l_ptr->bearer_id] = l_ptr; 346 n_ptr->link_cnt++; 347 } 348 349 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 350 { 351 int i; 352 353 for (i = 0; i < MAX_BEARERS; i++) { 354 if (l_ptr != n_ptr->links[i]) 355 continue; 356 n_ptr->links[i] = NULL; 357 n_ptr->link_cnt--; 358 } 359 } 360 361 static void node_established_contact(struct tipc_node *n_ptr) 362 { 363 n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP; 364 n_ptr->bclink.oos_state = 0; 365 n_ptr->bclink.acked = tipc_bclink_get_last_sent(n_ptr->net); 366 tipc_bclink_add_node(n_ptr->net, n_ptr->addr); 367 } 368 369 static void node_lost_contact(struct tipc_node *n_ptr) 370 { 371 char addr_string[16]; 372 struct tipc_sock_conn *conn, *safe; 373 struct list_head *conns = &n_ptr->conn_sks; 374 struct sk_buff *skb; 375 struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id); 376 uint i; 377 378 pr_debug("Lost contact with %s\n", 379 tipc_addr_string_fill(addr_string, n_ptr->addr)); 380 381 /* Flush broadcast link info associated with lost node */ 382 if (n_ptr->bclink.recv_permitted) { 383 __skb_queue_purge(&n_ptr->bclink.deferdq); 384 385 if (n_ptr->bclink.reasm_buf) { 386 kfree_skb(n_ptr->bclink.reasm_buf); 387 n_ptr->bclink.reasm_buf = NULL; 388 } 389 390 tipc_bclink_remove_node(n_ptr->net, n_ptr->addr); 391 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ); 392 393 n_ptr->bclink.recv_permitted = false; 394 } 395 396 /* Abort any ongoing link failover */ 397 for (i = 0; i < MAX_BEARERS; i++) { 398 struct tipc_link *l_ptr = n_ptr->links[i]; 399 if (!l_ptr) 400 continue; 401 l_ptr->flags &= ~LINK_FAILINGOVER; 402 l_ptr->failover_checkpt = 0; 403 l_ptr->failover_pkts = 0; 404 kfree_skb(l_ptr->failover_skb); 405 l_ptr->failover_skb = NULL; 406 tipc_link_reset_fragments(l_ptr); 407 } 408 409 n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN; 410 411 /* Prevent re-contact with node until cleanup is done */ 412 n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN; 413 414 /* Notify publications from this node */ 415 n_ptr->action_flags |= TIPC_NOTIFY_NODE_DOWN; 416 417 /* Notify sockets connected to node */ 418 list_for_each_entry_safe(conn, safe, conns, list) { 419 skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG, 420 SHORT_H_SIZE, 0, tn->own_addr, 421 conn->peer_node, conn->port, 422 conn->peer_port, TIPC_ERR_NO_NODE); 423 if (likely(skb)) { 424 skb_queue_tail(n_ptr->inputq, skb); 425 n_ptr->action_flags |= TIPC_MSG_EVT; 426 } 427 list_del(&conn->list); 428 kfree(conn); 429 } 430 } 431 432 /** 433 * tipc_node_get_linkname - get the name of a link 434 * 435 * @bearer_id: id of the bearer 436 * @node: peer node address 437 * @linkname: link name output buffer 438 * 439 * Returns 0 on success 440 */ 441 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr, 442 char *linkname, size_t len) 443 { 444 struct tipc_link *link; 445 int err = -EINVAL; 446 struct tipc_node *node = tipc_node_find(net, addr); 447 448 if (!node) 449 return err; 450 451 if (bearer_id >= MAX_BEARERS) 452 goto exit; 453 454 tipc_node_lock(node); 455 link = node->links[bearer_id]; 456 if (link) { 457 strncpy(linkname, link->name, len); 458 err = 0; 459 } 460 exit: 461 tipc_node_unlock(node); 462 tipc_node_put(node); 463 return err; 464 } 465 466 void tipc_node_unlock(struct tipc_node *node) 467 { 468 struct net *net = node->net; 469 u32 addr = 0; 470 u32 flags = node->action_flags; 471 u32 link_id = 0; 472 struct list_head *publ_list; 473 struct sk_buff_head *inputq = node->inputq; 474 struct sk_buff_head *namedq; 475 476 if (likely(!flags || (flags == TIPC_MSG_EVT))) { 477 node->action_flags = 0; 478 spin_unlock_bh(&node->lock); 479 if (flags == TIPC_MSG_EVT) 480 tipc_sk_rcv(net, inputq); 481 return; 482 } 483 484 addr = node->addr; 485 link_id = node->link_id; 486 namedq = node->namedq; 487 publ_list = &node->publ_list; 488 489 node->action_flags &= ~(TIPC_MSG_EVT | 490 TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP | 491 TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP | 492 TIPC_WAKEUP_BCAST_USERS | TIPC_BCAST_MSG_EVT | 493 TIPC_NAMED_MSG_EVT | TIPC_BCAST_RESET); 494 495 spin_unlock_bh(&node->lock); 496 497 if (flags & TIPC_NOTIFY_NODE_DOWN) 498 tipc_publ_notify(net, publ_list, addr); 499 500 if (flags & TIPC_WAKEUP_BCAST_USERS) 501 tipc_bclink_wakeup_users(net); 502 503 if (flags & TIPC_NOTIFY_NODE_UP) 504 tipc_named_node_up(net, addr); 505 506 if (flags & TIPC_NOTIFY_LINK_UP) 507 tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr, 508 TIPC_NODE_SCOPE, link_id, addr); 509 510 if (flags & TIPC_NOTIFY_LINK_DOWN) 511 tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr, 512 link_id, addr); 513 514 if (flags & TIPC_MSG_EVT) 515 tipc_sk_rcv(net, inputq); 516 517 if (flags & TIPC_NAMED_MSG_EVT) 518 tipc_named_rcv(net, namedq); 519 520 if (flags & TIPC_BCAST_MSG_EVT) 521 tipc_bclink_input(net); 522 523 if (flags & TIPC_BCAST_RESET) 524 tipc_link_reset_all(node); 525 } 526 527 /* Caller should hold node lock for the passed node */ 528 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node) 529 { 530 void *hdr; 531 struct nlattr *attrs; 532 533 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, 534 NLM_F_MULTI, TIPC_NL_NODE_GET); 535 if (!hdr) 536 return -EMSGSIZE; 537 538 attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE); 539 if (!attrs) 540 goto msg_full; 541 542 if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr)) 543 goto attr_msg_full; 544 if (tipc_node_is_up(node)) 545 if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP)) 546 goto attr_msg_full; 547 548 nla_nest_end(msg->skb, attrs); 549 genlmsg_end(msg->skb, hdr); 550 551 return 0; 552 553 attr_msg_full: 554 nla_nest_cancel(msg->skb, attrs); 555 msg_full: 556 genlmsg_cancel(msg->skb, hdr); 557 558 return -EMSGSIZE; 559 } 560 561 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb) 562 { 563 int err; 564 struct net *net = sock_net(skb->sk); 565 struct tipc_net *tn = net_generic(net, tipc_net_id); 566 int done = cb->args[0]; 567 int last_addr = cb->args[1]; 568 struct tipc_node *node; 569 struct tipc_nl_msg msg; 570 571 if (done) 572 return 0; 573 574 msg.skb = skb; 575 msg.portid = NETLINK_CB(cb->skb).portid; 576 msg.seq = cb->nlh->nlmsg_seq; 577 578 rcu_read_lock(); 579 if (last_addr) { 580 node = tipc_node_find(net, last_addr); 581 if (!node) { 582 rcu_read_unlock(); 583 /* We never set seq or call nl_dump_check_consistent() 584 * this means that setting prev_seq here will cause the 585 * consistence check to fail in the netlink callback 586 * handler. Resulting in the NLMSG_DONE message having 587 * the NLM_F_DUMP_INTR flag set if the node state 588 * changed while we released the lock. 589 */ 590 cb->prev_seq = 1; 591 return -EPIPE; 592 } 593 tipc_node_put(node); 594 } 595 596 list_for_each_entry_rcu(node, &tn->node_list, list) { 597 if (last_addr) { 598 if (node->addr == last_addr) 599 last_addr = 0; 600 else 601 continue; 602 } 603 604 tipc_node_lock(node); 605 err = __tipc_nl_add_node(&msg, node); 606 if (err) { 607 last_addr = node->addr; 608 tipc_node_unlock(node); 609 goto out; 610 } 611 612 tipc_node_unlock(node); 613 } 614 done = 1; 615 out: 616 cb->args[0] = done; 617 cb->args[1] = last_addr; 618 rcu_read_unlock(); 619 620 return skb->len; 621 } 622