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 "config.h" 39 #include "node.h" 40 #include "name_distr.h" 41 #include "socket.h" 42 43 #define NODE_HTABLE_SIZE 512 44 45 static void node_lost_contact(struct tipc_node *n_ptr); 46 static void node_established_contact(struct tipc_node *n_ptr); 47 48 static struct hlist_head node_htable[NODE_HTABLE_SIZE]; 49 LIST_HEAD(tipc_node_list); 50 static u32 tipc_num_nodes; 51 static u32 tipc_num_links; 52 static DEFINE_SPINLOCK(node_list_lock); 53 54 struct tipc_sock_conn { 55 u32 port; 56 u32 peer_port; 57 u32 peer_node; 58 struct list_head list; 59 }; 60 61 static const struct nla_policy tipc_nl_node_policy[TIPC_NLA_NODE_MAX + 1] = { 62 [TIPC_NLA_NODE_UNSPEC] = { .type = NLA_UNSPEC }, 63 [TIPC_NLA_NODE_ADDR] = { .type = NLA_U32 }, 64 [TIPC_NLA_NODE_UP] = { .type = NLA_FLAG } 65 }; 66 67 /* 68 * A trivial power-of-two bitmask technique is used for speed, since this 69 * operation is done for every incoming TIPC packet. The number of hash table 70 * entries has been chosen so that no hash chain exceeds 8 nodes and will 71 * usually be much smaller (typically only a single node). 72 */ 73 static unsigned int tipc_hashfn(u32 addr) 74 { 75 return addr & (NODE_HTABLE_SIZE - 1); 76 } 77 78 /* 79 * tipc_node_find - locate specified node object, if it exists 80 */ 81 struct tipc_node *tipc_node_find(u32 addr) 82 { 83 struct tipc_node *node; 84 85 if (unlikely(!in_own_cluster_exact(addr))) 86 return NULL; 87 88 rcu_read_lock(); 89 hlist_for_each_entry_rcu(node, &node_htable[tipc_hashfn(addr)], hash) { 90 if (node->addr == addr) { 91 rcu_read_unlock(); 92 return node; 93 } 94 } 95 rcu_read_unlock(); 96 return NULL; 97 } 98 99 struct tipc_node *tipc_node_create(u32 addr) 100 { 101 struct tipc_node *n_ptr, *temp_node; 102 103 spin_lock_bh(&node_list_lock); 104 105 n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC); 106 if (!n_ptr) { 107 spin_unlock_bh(&node_list_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->publ_list); 117 INIT_LIST_HEAD(&n_ptr->conn_sks); 118 skb_queue_head_init(&n_ptr->waiting_sks); 119 __skb_queue_head_init(&n_ptr->bclink.deferred_queue); 120 121 hlist_add_head_rcu(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]); 122 123 list_for_each_entry_rcu(temp_node, &tipc_node_list, list) { 124 if (n_ptr->addr < temp_node->addr) 125 break; 126 } 127 list_add_tail_rcu(&n_ptr->list, &temp_node->list); 128 n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN; 129 n_ptr->signature = INVALID_NODE_SIG; 130 131 tipc_num_nodes++; 132 133 spin_unlock_bh(&node_list_lock); 134 return n_ptr; 135 } 136 137 static void tipc_node_delete(struct tipc_node *n_ptr) 138 { 139 list_del_rcu(&n_ptr->list); 140 hlist_del_rcu(&n_ptr->hash); 141 kfree_rcu(n_ptr, rcu); 142 143 tipc_num_nodes--; 144 } 145 146 void tipc_node_stop(void) 147 { 148 struct tipc_node *node, *t_node; 149 150 spin_lock_bh(&node_list_lock); 151 list_for_each_entry_safe(node, t_node, &tipc_node_list, list) 152 tipc_node_delete(node); 153 spin_unlock_bh(&node_list_lock); 154 } 155 156 int tipc_node_add_conn(u32 dnode, u32 port, u32 peer_port) 157 { 158 struct tipc_node *node; 159 struct tipc_sock_conn *conn; 160 161 if (in_own_node(dnode)) 162 return 0; 163 164 node = tipc_node_find(dnode); 165 if (!node) { 166 pr_warn("Connecting sock to node 0x%x failed\n", dnode); 167 return -EHOSTUNREACH; 168 } 169 conn = kmalloc(sizeof(*conn), GFP_ATOMIC); 170 if (!conn) 171 return -EHOSTUNREACH; 172 conn->peer_node = dnode; 173 conn->port = port; 174 conn->peer_port = peer_port; 175 176 tipc_node_lock(node); 177 list_add_tail(&conn->list, &node->conn_sks); 178 tipc_node_unlock(node); 179 return 0; 180 } 181 182 void tipc_node_remove_conn(u32 dnode, u32 port) 183 { 184 struct tipc_node *node; 185 struct tipc_sock_conn *conn, *safe; 186 187 if (in_own_node(dnode)) 188 return; 189 190 node = tipc_node_find(dnode); 191 if (!node) 192 return; 193 194 tipc_node_lock(node); 195 list_for_each_entry_safe(conn, safe, &node->conn_sks, list) { 196 if (port != conn->port) 197 continue; 198 list_del(&conn->list); 199 kfree(conn); 200 } 201 tipc_node_unlock(node); 202 } 203 204 void tipc_node_abort_sock_conns(struct list_head *conns) 205 { 206 struct tipc_sock_conn *conn, *safe; 207 struct sk_buff *buf; 208 209 list_for_each_entry_safe(conn, safe, conns, list) { 210 buf = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG, 211 SHORT_H_SIZE, 0, tipc_own_addr, 212 conn->peer_node, conn->port, 213 conn->peer_port, TIPC_ERR_NO_NODE); 214 if (likely(buf)) 215 tipc_sk_rcv(buf); 216 list_del(&conn->list); 217 kfree(conn); 218 } 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_info("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_info("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_info("Old link <%s> becomes standby\n", active[0]->name); 252 if (active[1] != active[0]) 253 pr_info("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]->max_pkt - INT_H_SIZE; 258 n_ptr->act_mtus[1] = active[1]->max_pkt - 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_link **active; 294 295 n_ptr->working_links--; 296 n_ptr->action_flags |= TIPC_NOTIFY_LINK_DOWN; 297 n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id; 298 299 if (!tipc_link_is_active(l_ptr)) { 300 pr_info("Lost standby link <%s> on network plane %c\n", 301 l_ptr->name, l_ptr->net_plane); 302 return; 303 } 304 pr_info("Lost link <%s> on network plane %c\n", 305 l_ptr->name, l_ptr->net_plane); 306 307 active = &n_ptr->active_links[0]; 308 if (active[0] == l_ptr) 309 active[0] = active[1]; 310 if (active[1] == l_ptr) 311 active[1] = active[0]; 312 if (active[0] == l_ptr) 313 node_select_active_links(n_ptr); 314 if (tipc_node_is_up(n_ptr)) 315 tipc_link_failover_send_queue(l_ptr); 316 else 317 node_lost_contact(n_ptr); 318 319 /* Leave room for changeover header when returning 'mtu' to users: */ 320 if (active[0]) { 321 n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE; 322 n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE; 323 return; 324 } 325 326 /* Loopback link went down? No fragmentation needed from now on. */ 327 if (n_ptr->addr == tipc_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 spin_lock_bh(&node_list_lock); 347 tipc_num_links++; 348 spin_unlock_bh(&node_list_lock); 349 n_ptr->link_cnt++; 350 } 351 352 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) 353 { 354 int i; 355 356 for (i = 0; i < MAX_BEARERS; i++) { 357 if (l_ptr != n_ptr->links[i]) 358 continue; 359 n_ptr->links[i] = NULL; 360 spin_lock_bh(&node_list_lock); 361 tipc_num_links--; 362 spin_unlock_bh(&node_list_lock); 363 n_ptr->link_cnt--; 364 } 365 } 366 367 static void node_established_contact(struct tipc_node *n_ptr) 368 { 369 n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP; 370 n_ptr->bclink.oos_state = 0; 371 n_ptr->bclink.acked = tipc_bclink_get_last_sent(); 372 tipc_bclink_add_node(n_ptr->addr); 373 } 374 375 static void node_lost_contact(struct tipc_node *n_ptr) 376 { 377 char addr_string[16]; 378 u32 i; 379 380 pr_info("Lost contact with %s\n", 381 tipc_addr_string_fill(addr_string, n_ptr->addr)); 382 383 /* Flush broadcast link info associated with lost node */ 384 if (n_ptr->bclink.recv_permitted) { 385 __skb_queue_purge(&n_ptr->bclink.deferred_queue); 386 387 if (n_ptr->bclink.reasm_buf) { 388 kfree_skb(n_ptr->bclink.reasm_buf); 389 n_ptr->bclink.reasm_buf = NULL; 390 } 391 392 tipc_bclink_remove_node(n_ptr->addr); 393 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ); 394 395 n_ptr->bclink.recv_permitted = false; 396 } 397 398 /* Abort link changeover */ 399 for (i = 0; i < MAX_BEARERS; i++) { 400 struct tipc_link *l_ptr = n_ptr->links[i]; 401 if (!l_ptr) 402 continue; 403 l_ptr->reset_checkpoint = l_ptr->next_in_no; 404 l_ptr->exp_msg_count = 0; 405 tipc_link_reset_fragments(l_ptr); 406 } 407 408 n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN; 409 410 /* Notify subscribers and prevent re-contact with node until 411 * cleanup is done. 412 */ 413 n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN | 414 TIPC_NOTIFY_NODE_DOWN; 415 } 416 417 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space) 418 { 419 u32 domain; 420 struct sk_buff *buf; 421 struct tipc_node *n_ptr; 422 struct tipc_node_info node_info; 423 u32 payload_size; 424 425 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR)) 426 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); 427 428 domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area)); 429 if (!tipc_addr_domain_valid(domain)) 430 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE 431 " (network address)"); 432 433 spin_lock_bh(&node_list_lock); 434 if (!tipc_num_nodes) { 435 spin_unlock_bh(&node_list_lock); 436 return tipc_cfg_reply_none(); 437 } 438 439 /* For now, get space for all other nodes */ 440 payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes; 441 if (payload_size > 32768u) { 442 spin_unlock_bh(&node_list_lock); 443 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED 444 " (too many nodes)"); 445 } 446 spin_unlock_bh(&node_list_lock); 447 448 buf = tipc_cfg_reply_alloc(payload_size); 449 if (!buf) 450 return NULL; 451 452 /* Add TLVs for all nodes in scope */ 453 rcu_read_lock(); 454 list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) { 455 if (!tipc_in_scope(domain, n_ptr->addr)) 456 continue; 457 node_info.addr = htonl(n_ptr->addr); 458 node_info.up = htonl(tipc_node_is_up(n_ptr)); 459 tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO, 460 &node_info, sizeof(node_info)); 461 } 462 rcu_read_unlock(); 463 return buf; 464 } 465 466 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space) 467 { 468 u32 domain; 469 struct sk_buff *buf; 470 struct tipc_node *n_ptr; 471 struct tipc_link_info link_info; 472 u32 payload_size; 473 474 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR)) 475 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); 476 477 domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area)); 478 if (!tipc_addr_domain_valid(domain)) 479 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE 480 " (network address)"); 481 482 if (!tipc_own_addr) 483 return tipc_cfg_reply_none(); 484 485 spin_lock_bh(&node_list_lock); 486 /* Get space for all unicast links + broadcast link */ 487 payload_size = TLV_SPACE((sizeof(link_info)) * (tipc_num_links + 1)); 488 if (payload_size > 32768u) { 489 spin_unlock_bh(&node_list_lock); 490 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED 491 " (too many links)"); 492 } 493 spin_unlock_bh(&node_list_lock); 494 495 buf = tipc_cfg_reply_alloc(payload_size); 496 if (!buf) 497 return NULL; 498 499 /* Add TLV for broadcast link */ 500 link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr)); 501 link_info.up = htonl(1); 502 strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME); 503 tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info)); 504 505 /* Add TLVs for any other links in scope */ 506 rcu_read_lock(); 507 list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) { 508 u32 i; 509 510 if (!tipc_in_scope(domain, n_ptr->addr)) 511 continue; 512 tipc_node_lock(n_ptr); 513 for (i = 0; i < MAX_BEARERS; i++) { 514 if (!n_ptr->links[i]) 515 continue; 516 link_info.dest = htonl(n_ptr->addr); 517 link_info.up = htonl(tipc_link_is_up(n_ptr->links[i])); 518 strcpy(link_info.str, n_ptr->links[i]->name); 519 tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, 520 &link_info, sizeof(link_info)); 521 } 522 tipc_node_unlock(n_ptr); 523 } 524 rcu_read_unlock(); 525 return buf; 526 } 527 528 /** 529 * tipc_node_get_linkname - get the name of a link 530 * 531 * @bearer_id: id of the bearer 532 * @node: peer node address 533 * @linkname: link name output buffer 534 * 535 * Returns 0 on success 536 */ 537 int tipc_node_get_linkname(u32 bearer_id, u32 addr, char *linkname, size_t len) 538 { 539 struct tipc_link *link; 540 struct tipc_node *node = tipc_node_find(addr); 541 542 if ((bearer_id >= MAX_BEARERS) || !node) 543 return -EINVAL; 544 tipc_node_lock(node); 545 link = node->links[bearer_id]; 546 if (link) { 547 strncpy(linkname, link->name, len); 548 tipc_node_unlock(node); 549 return 0; 550 } 551 tipc_node_unlock(node); 552 return -EINVAL; 553 } 554 555 void tipc_node_unlock(struct tipc_node *node) 556 { 557 LIST_HEAD(nsub_list); 558 LIST_HEAD(conn_sks); 559 struct sk_buff_head waiting_sks; 560 u32 addr = 0; 561 int flags = node->action_flags; 562 u32 link_id = 0; 563 564 if (likely(!flags)) { 565 spin_unlock_bh(&node->lock); 566 return; 567 } 568 569 addr = node->addr; 570 link_id = node->link_id; 571 __skb_queue_head_init(&waiting_sks); 572 573 if (flags & TIPC_WAKEUP_USERS) 574 skb_queue_splice_init(&node->waiting_sks, &waiting_sks); 575 576 if (flags & TIPC_NOTIFY_NODE_DOWN) { 577 list_replace_init(&node->publ_list, &nsub_list); 578 list_replace_init(&node->conn_sks, &conn_sks); 579 } 580 node->action_flags &= ~(TIPC_WAKEUP_USERS | TIPC_NOTIFY_NODE_DOWN | 581 TIPC_NOTIFY_NODE_UP | TIPC_NOTIFY_LINK_UP | 582 TIPC_NOTIFY_LINK_DOWN | 583 TIPC_WAKEUP_BCAST_USERS); 584 585 spin_unlock_bh(&node->lock); 586 587 while (!skb_queue_empty(&waiting_sks)) 588 tipc_sk_rcv(__skb_dequeue(&waiting_sks)); 589 590 if (!list_empty(&conn_sks)) 591 tipc_node_abort_sock_conns(&conn_sks); 592 593 if (!list_empty(&nsub_list)) 594 tipc_publ_notify(&nsub_list, addr); 595 596 if (flags & TIPC_WAKEUP_BCAST_USERS) 597 tipc_bclink_wakeup_users(); 598 599 if (flags & TIPC_NOTIFY_NODE_UP) 600 tipc_named_node_up(addr); 601 602 if (flags & TIPC_NOTIFY_LINK_UP) 603 tipc_nametbl_publish(TIPC_LINK_STATE, addr, addr, 604 TIPC_NODE_SCOPE, link_id, addr); 605 606 if (flags & TIPC_NOTIFY_LINK_DOWN) 607 tipc_nametbl_withdraw(TIPC_LINK_STATE, addr, 608 link_id, addr); 609 } 610 611 /* Caller should hold node lock for the passed node */ 612 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node) 613 { 614 void *hdr; 615 struct nlattr *attrs; 616 617 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_v2_family, 618 NLM_F_MULTI, TIPC_NL_NODE_GET); 619 if (!hdr) 620 return -EMSGSIZE; 621 622 attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE); 623 if (!attrs) 624 goto msg_full; 625 626 if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr)) 627 goto attr_msg_full; 628 if (tipc_node_is_up(node)) 629 if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP)) 630 goto attr_msg_full; 631 632 nla_nest_end(msg->skb, attrs); 633 genlmsg_end(msg->skb, hdr); 634 635 return 0; 636 637 attr_msg_full: 638 nla_nest_cancel(msg->skb, attrs); 639 msg_full: 640 genlmsg_cancel(msg->skb, hdr); 641 642 return -EMSGSIZE; 643 } 644 645 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb) 646 { 647 int err; 648 int done = cb->args[0]; 649 int last_addr = cb->args[1]; 650 struct tipc_node *node; 651 struct tipc_nl_msg msg; 652 653 if (done) 654 return 0; 655 656 msg.skb = skb; 657 msg.portid = NETLINK_CB(cb->skb).portid; 658 msg.seq = cb->nlh->nlmsg_seq; 659 660 rcu_read_lock(); 661 662 if (last_addr && !tipc_node_find(last_addr)) { 663 rcu_read_unlock(); 664 /* We never set seq or call nl_dump_check_consistent() this 665 * means that setting prev_seq here will cause the consistence 666 * check to fail in the netlink callback handler. Resulting in 667 * the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if 668 * the node state changed while we released the lock. 669 */ 670 cb->prev_seq = 1; 671 return -EPIPE; 672 } 673 674 list_for_each_entry_rcu(node, &tipc_node_list, list) { 675 if (last_addr) { 676 if (node->addr == last_addr) 677 last_addr = 0; 678 else 679 continue; 680 } 681 682 tipc_node_lock(node); 683 err = __tipc_nl_add_node(&msg, node); 684 if (err) { 685 last_addr = node->addr; 686 tipc_node_unlock(node); 687 goto out; 688 } 689 690 tipc_node_unlock(node); 691 } 692 done = 1; 693 out: 694 cb->args[0] = done; 695 cb->args[1] = last_addr; 696 rcu_read_unlock(); 697 698 return skb->len; 699 } 700