net/tipc/node.c

   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->nsub);
 117         INIT_LIST_HEAD(&n_ptr->conn_sks);
 118         __skb_queue_head_init(&n_ptr->waiting_sks);
 119
 120         hlist_add_head_rcu(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
 121
 122         list_for_each_entry_rcu(temp_node, &tipc_node_list, list) {
 123                 if (n_ptr->addr < temp_node->addr)
 124                         break;
 125         }
 126         list_add_tail_rcu(&n_ptr->list, &temp_node->list);
 127         n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN;
 128         n_ptr->signature = INVALID_NODE_SIG;
 129
 130         tipc_num_nodes++;
 131
 132         spin_unlock_bh(&node_list_lock);
 133         return n_ptr;
 134 }
 135
 136 static void tipc_node_delete(struct tipc_node *n_ptr)
 137 {
 138         list_del_rcu(&n_ptr->list);
 139         hlist_del_rcu(&n_ptr->hash);
 140         kfree_rcu(n_ptr, rcu);
 141
 142         tipc_num_nodes--;
 143 }
 144
 145 void tipc_node_stop(void)
 146 {
 147         struct tipc_node *node, *t_node;
 148
 149         spin_lock_bh(&node_list_lock);
 150         list_for_each_entry_safe(node, t_node, &tipc_node_list, list)
 151                 tipc_node_delete(node);
 152         spin_unlock_bh(&node_list_lock);
 153 }
 154
 155 int tipc_node_add_conn(u32 dnode, u32 port, u32 peer_port)
 156 {
 157         struct tipc_node *node;
 158         struct tipc_sock_conn *conn;
 159
 160         if (in_own_node(dnode))
 161                 return 0;
 162
 163         node = tipc_node_find(dnode);
 164         if (!node) {
 165                 pr_warn("Connecting sock to node 0x%x failed\n", dnode);
 166                 return -EHOSTUNREACH;
 167         }
 168         conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
 169         if (!conn)
 170                 return -EHOSTUNREACH;
 171         conn->peer_node = dnode;
 172         conn->port = port;
 173         conn->peer_port = peer_port;
 174
 175         tipc_node_lock(node);
 176         list_add_tail(&conn->list, &node->conn_sks);
 177         tipc_node_unlock(node);
 178         return 0;
 179 }
 180
 181 void tipc_node_remove_conn(u32 dnode, u32 port)
 182 {
 183         struct tipc_node *node;
 184         struct tipc_sock_conn *conn, *safe;
 185
 186         if (in_own_node(dnode))
 187                 return;
 188
 189         node = tipc_node_find(dnode);
 190         if (!node)
 191                 return;
 192
 193         tipc_node_lock(node);
 194         list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
 195                 if (port != conn->port)
 196                         continue;
 197                 list_del(&conn->list);
 198                 kfree(conn);
 199         }
 200         tipc_node_unlock(node);
 201 }
 202
 203 void tipc_node_abort_sock_conns(struct list_head *conns)
 204 {
 205         struct tipc_sock_conn *conn, *safe;
 206         struct sk_buff *buf;
 207
 208         list_for_each_entry_safe(conn, safe, conns, list) {
 209                 buf = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
 210                                       SHORT_H_SIZE, 0, tipc_own_addr,
 211                                       conn->peer_node, conn->port,
 212                                       conn->peer_port, TIPC_ERR_NO_NODE);
 213                 if (likely(buf))
 214                         tipc_sk_rcv(buf);
 215                 list_del(&conn->list);
 216                 kfree(conn);
 217         }
 218 }
 219
 220 /**
 221  * tipc_node_link_up - handle addition of link
 222  *
 223  * Link becomes active (alone or shared) or standby, depending on its priority.
 224  */
 225 void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 226 {
 227         struct tipc_link **active = &n_ptr->active_links[0];
 228
 229         n_ptr->working_links++;
 230         n_ptr->action_flags |= TIPC_NOTIFY_LINK_UP;
 231         n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id;
 232
 233         pr_info("Established link <%s> on network plane %c\n",
 234                 l_ptr->name, l_ptr->net_plane);
 235
 236         if (!active[0]) {
 237                 active[0] = active[1] = l_ptr;
 238                 node_established_contact(n_ptr);
 239                 goto exit;
 240         }
 241         if (l_ptr->priority < active[0]->priority) {
 242                 pr_info("New link <%s> becomes standby\n", l_ptr->name);
 243                 goto exit;
 244         }
 245         tipc_link_dup_queue_xmit(active[0], l_ptr);
 246         if (l_ptr->priority == active[0]->priority) {
 247                 active[0] = l_ptr;
 248                 goto exit;
 249         }
 250         pr_info("Old link <%s> becomes standby\n", active[0]->name);
 251         if (active[1] != active[0])
 252                 pr_info("Old link <%s> becomes standby\n", active[1]->name);
 253         active[0] = active[1] = l_ptr;
 254 exit:
 255         /* Leave room for changeover header when returning 'mtu' to users: */
 256         n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
 257         n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
 258 }
 259
 260 /**
 261  * node_select_active_links - select active link
 262  */
 263 static void node_select_active_links(struct tipc_node *n_ptr)
 264 {
 265         struct tipc_link **active = &n_ptr->active_links[0];
 266         u32 i;
 267         u32 highest_prio = 0;
 268
 269         active[0] = active[1] = NULL;
 270
 271         for (i = 0; i < MAX_BEARERS; i++) {
 272                 struct tipc_link *l_ptr = n_ptr->links[i];
 273
 274                 if (!l_ptr || !tipc_link_is_up(l_ptr) ||
 275                     (l_ptr->priority < highest_prio))
 276                         continue;
 277
 278                 if (l_ptr->priority > highest_prio) {
 279                         highest_prio = l_ptr->priority;
 280                         active[0] = active[1] = l_ptr;
 281                 } else {
 282                         active[1] = l_ptr;
 283                 }
 284         }
 285 }
 286
 287 /**
 288  * tipc_node_link_down - handle loss of link
 289  */
 290 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 291 {
 292         struct tipc_link **active;
 293
 294         n_ptr->working_links--;
 295         n_ptr->action_flags |= TIPC_NOTIFY_LINK_DOWN;
 296         n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id;
 297
 298         if (!tipc_link_is_active(l_ptr)) {
 299                 pr_info("Lost standby link <%s> on network plane %c\n",
 300                         l_ptr->name, l_ptr->net_plane);
 301                 return;
 302         }
 303         pr_info("Lost link <%s> on network plane %c\n",
 304                 l_ptr->name, l_ptr->net_plane);
 305
 306         active = &n_ptr->active_links[0];
 307         if (active[0] == l_ptr)
 308                 active[0] = active[1];
 309         if (active[1] == l_ptr)
 310                 active[1] = active[0];
 311         if (active[0] == l_ptr)
 312                 node_select_active_links(n_ptr);
 313         if (tipc_node_is_up(n_ptr))
 314                 tipc_link_failover_send_queue(l_ptr);
 315         else
 316                 node_lost_contact(n_ptr);
 317
 318         /* Leave room for changeover header when returning 'mtu' to users: */
 319         if (active[0]) {
 320                 n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
 321                 n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
 322                 return;
 323         }
 324
 325         /* Loopback link went down? No fragmentation needed from now on. */
 326         if (n_ptr->addr == tipc_own_addr) {
 327                 n_ptr->act_mtus[0] = MAX_MSG_SIZE;
 328                 n_ptr->act_mtus[1] = MAX_MSG_SIZE;
 329         }
 330 }
 331
 332 int tipc_node_active_links(struct tipc_node *n_ptr)
 333 {
 334         return n_ptr->active_links[0] != NULL;
 335 }
 336
 337 int tipc_node_is_up(struct tipc_node *n_ptr)
 338 {
 339         return tipc_node_active_links(n_ptr);
 340 }
 341
 342 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 343 {
 344         n_ptr->links[l_ptr->bearer_id] = l_ptr;
 345         spin_lock_bh(&node_list_lock);
 346         tipc_num_links++;
 347         spin_unlock_bh(&node_list_lock);
 348         n_ptr->link_cnt++;
 349 }
 350
 351 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 352 {
 353         int i;
 354
 355         for (i = 0; i < MAX_BEARERS; i++) {
 356                 if (l_ptr != n_ptr->links[i])
 357                         continue;
 358                 n_ptr->links[i] = NULL;
 359                 spin_lock_bh(&node_list_lock);
 360                 tipc_num_links--;
 361                 spin_unlock_bh(&node_list_lock);
 362                 n_ptr->link_cnt--;
 363         }
 364 }
 365
 366 static void node_established_contact(struct tipc_node *n_ptr)
 367 {
 368         n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
 369         n_ptr->bclink.oos_state = 0;
 370         n_ptr->bclink.acked = tipc_bclink_get_last_sent();
 371         tipc_bclink_add_node(n_ptr->addr);
 372 }
 373
 374 static void node_lost_contact(struct tipc_node *n_ptr)
 375 {
 376         char addr_string[16];
 377         u32 i;
 378
 379         pr_info("Lost contact with %s\n",
 380                 tipc_addr_string_fill(addr_string, n_ptr->addr));
 381
 382         /* Flush broadcast link info associated with lost node */
 383         if (n_ptr->bclink.recv_permitted) {
 384                 kfree_skb_list(n_ptr->bclink.deferred_head);
 385                 n_ptr->bclink.deferred_size = 0;
 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->nsub, &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_nodesub_notify(&nsub_list);
 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 }