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 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
 100         n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
 101         if (!n_ptr) {
 102                 spin_unlock_bh(&tn->node_list_lock);
 103                 pr_warn("Node creation failed, no memory\n");
 104                 return NULL;
 105         }
 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->waiting_sks);
 115         __skb_queue_head_init(&n_ptr->bclink.deferred_queue);
 116
 117         hlist_add_head_rcu(&n_ptr->hash, &tn->node_htable[tipc_hashfn(addr)]);
 118
 119         list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
 120                 if (n_ptr->addr < temp_node->addr)
 121                         break;
 122         }
 123         list_add_tail_rcu(&n_ptr->list, &temp_node->list);
 124         n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN;
 125         n_ptr->signature = INVALID_NODE_SIG;
 126
 127         tn->num_nodes++;
 128
 129         spin_unlock_bh(&tn->node_list_lock);
 130         return n_ptr;
 131 }
 132
 133 static void tipc_node_delete(struct tipc_net *tn, struct tipc_node *n_ptr)
 134 {
 135         list_del_rcu(&n_ptr->list);
 136         hlist_del_rcu(&n_ptr->hash);
 137         kfree_rcu(n_ptr, rcu);
 138
 139         tn->num_nodes--;
 140 }
 141
 142 void tipc_node_stop(struct net *net)
 143 {
 144         struct tipc_net *tn = net_generic(net, tipc_net_id);
 145         struct tipc_node *node, *t_node;
 146
 147         spin_lock_bh(&tn->node_list_lock);
 148         list_for_each_entry_safe(node, t_node, &tn->node_list, list)
 149                 tipc_node_delete(tn, node);
 150         spin_unlock_bh(&tn->node_list_lock);
 151 }
 152
 153 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
 154 {
 155         struct tipc_node *node;
 156         struct tipc_sock_conn *conn;
 157
 158         if (in_own_node(net, dnode))
 159                 return 0;
 160
 161         node = tipc_node_find(net, dnode);
 162         if (!node) {
 163                 pr_warn("Connecting sock to node 0x%x failed\n", dnode);
 164                 return -EHOSTUNREACH;
 165         }
 166         conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
 167         if (!conn)
 168                 return -EHOSTUNREACH;
 169         conn->peer_node = dnode;
 170         conn->port = port;
 171         conn->peer_port = peer_port;
 172
 173         tipc_node_lock(node);
 174         list_add_tail(&conn->list, &node->conn_sks);
 175         tipc_node_unlock(node);
 176         return 0;
 177 }
 178
 179 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
 180 {
 181         struct tipc_node *node;
 182         struct tipc_sock_conn *conn, *safe;
 183
 184         if (in_own_node(net, dnode))
 185                 return;
 186
 187         node = tipc_node_find(net, dnode);
 188         if (!node)
 189                 return;
 190
 191         tipc_node_lock(node);
 192         list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
 193                 if (port != conn->port)
 194                         continue;
 195                 list_del(&conn->list);
 196                 kfree(conn);
 197         }
 198         tipc_node_unlock(node);
 199 }
 200
 201 void tipc_node_abort_sock_conns(struct net *net, struct list_head *conns)
 202 {
 203         struct tipc_net *tn = net_generic(net, tipc_net_id);
 204         struct tipc_sock_conn *conn, *safe;
 205         struct sk_buff *buf;
 206
 207         list_for_each_entry_safe(conn, safe, conns, list) {
 208                 buf = tipc_msg_create(net, TIPC_CRITICAL_IMPORTANCE,
 209                                       TIPC_CONN_MSG, SHORT_H_SIZE, 0,
 210                                       tn->own_addr, conn->peer_node,
 211                                       conn->port, conn->peer_port,
 212                                       TIPC_ERR_NO_NODE);
 213                 if (likely(buf))
 214                         tipc_sk_rcv(net, 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_debug("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_debug("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_debug("Old link <%s> becomes standby\n", active[0]->name);
 251         if (active[1] != active[0])
 252                 pr_debug("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_net *tn = net_generic(n_ptr->net, tipc_net_id);
 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_debug("Lost standby link <%s> on network plane %c\n",
 301                          l_ptr->name, l_ptr->net_plane);
 302                 return;
 303         }
 304         pr_debug("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 == 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         struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
 346
 347         n_ptr->links[l_ptr->bearer_id] = l_ptr;
 348         spin_lock_bh(&tn->node_list_lock);
 349         tn->num_links++;
 350         spin_unlock_bh(&tn->node_list_lock);
 351         n_ptr->link_cnt++;
 352 }
 353
 354 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 355 {
 356         struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
 357         int i;
 358
 359         for (i = 0; i < MAX_BEARERS; i++) {
 360                 if (l_ptr != n_ptr->links[i])
 361                         continue;
 362                 n_ptr->links[i] = NULL;
 363                 spin_lock_bh(&tn->node_list_lock);
 364                 tn->num_links--;
 365                 spin_unlock_bh(&tn->node_list_lock);
 366                 n_ptr->link_cnt--;
 367         }
 368 }
 369
 370 static void node_established_contact(struct tipc_node *n_ptr)
 371 {
 372         n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
 373         n_ptr->bclink.oos_state = 0;
 374         n_ptr->bclink.acked = tipc_bclink_get_last_sent(n_ptr->net);
 375         tipc_bclink_add_node(n_ptr->net, n_ptr->addr);
 376 }
 377
 378 static void node_lost_contact(struct tipc_node *n_ptr)
 379 {
 380         char addr_string[16];
 381         u32 i;
 382
 383         pr_debug("Lost contact with %s\n",
 384                  tipc_addr_string_fill(addr_string, n_ptr->addr));
 385
 386         /* Flush broadcast link info associated with lost node */
 387         if (n_ptr->bclink.recv_permitted) {
 388                 __skb_queue_purge(&n_ptr->bclink.deferred_queue);
 389
 390                 if (n_ptr->bclink.reasm_buf) {
 391                         kfree_skb(n_ptr->bclink.reasm_buf);
 392                         n_ptr->bclink.reasm_buf = NULL;
 393                 }
 394
 395                 tipc_bclink_remove_node(n_ptr->net, n_ptr->addr);
 396                 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
 397
 398                 n_ptr->bclink.recv_permitted = false;
 399         }
 400
 401         /* Abort link changeover */
 402         for (i = 0; i < MAX_BEARERS; i++) {
 403                 struct tipc_link *l_ptr = n_ptr->links[i];
 404                 if (!l_ptr)
 405                         continue;
 406                 l_ptr->reset_checkpoint = l_ptr->next_in_no;
 407                 l_ptr->exp_msg_count = 0;
 408                 tipc_link_reset_fragments(l_ptr);
 409
 410                 /* Link marked for deletion after failover? => do it now */
 411                 if (l_ptr->flags & LINK_STOPPED)
 412                         tipc_link_delete(l_ptr);
 413         }
 414
 415         n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN;
 416
 417         /* Notify subscribers and prevent re-contact with node until
 418          * cleanup is done.
 419          */
 420         n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN |
 421                                TIPC_NOTIFY_NODE_DOWN;
 422 }
 423
 424 struct sk_buff *tipc_node_get_nodes(struct net *net, const void *req_tlv_area,
 425                                     int req_tlv_space)
 426 {
 427         struct tipc_net *tn = net_generic(net, tipc_net_id);
 428         u32 domain;
 429         struct sk_buff *buf;
 430         struct tipc_node *n_ptr;
 431         struct tipc_node_info node_info;
 432         u32 payload_size;
 433
 434         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
 435                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 436
 437         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
 438         if (!tipc_addr_domain_valid(domain))
 439                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 440                                                    " (network address)");
 441
 442         spin_lock_bh(&tn->node_list_lock);
 443         if (!tn->num_nodes) {
 444                 spin_unlock_bh(&tn->node_list_lock);
 445                 return tipc_cfg_reply_none();
 446         }
 447
 448         /* For now, get space for all other nodes */
 449         payload_size = TLV_SPACE(sizeof(node_info)) * tn->num_nodes;
 450         if (payload_size > 32768u) {
 451                 spin_unlock_bh(&tn->node_list_lock);
 452                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
 453                                                    " (too many nodes)");
 454         }
 455         spin_unlock_bh(&tn->node_list_lock);
 456
 457         buf = tipc_cfg_reply_alloc(payload_size);
 458         if (!buf)
 459                 return NULL;
 460
 461         /* Add TLVs for all nodes in scope */
 462         rcu_read_lock();
 463         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
 464                 if (!tipc_in_scope(domain, n_ptr->addr))
 465                         continue;
 466                 node_info.addr = htonl(n_ptr->addr);
 467                 node_info.up = htonl(tipc_node_is_up(n_ptr));
 468                 tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
 469                                     &node_info, sizeof(node_info));
 470         }
 471         rcu_read_unlock();
 472         return buf;
 473 }
 474
 475 struct sk_buff *tipc_node_get_links(struct net *net, const void *req_tlv_area,
 476                                     int req_tlv_space)
 477 {
 478         struct tipc_net *tn = net_generic(net, tipc_net_id);
 479         u32 domain;
 480         struct sk_buff *buf;
 481         struct tipc_node *n_ptr;
 482         struct tipc_link_info link_info;
 483         u32 payload_size;
 484
 485         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
 486                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 487
 488         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
 489         if (!tipc_addr_domain_valid(domain))
 490                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 491                                                    " (network address)");
 492
 493         if (!tn->own_addr)
 494                 return tipc_cfg_reply_none();
 495
 496         spin_lock_bh(&tn->node_list_lock);
 497         /* Get space for all unicast links + broadcast link */
 498         payload_size = TLV_SPACE((sizeof(link_info)) * (tn->num_links + 1));
 499         if (payload_size > 32768u) {
 500                 spin_unlock_bh(&tn->node_list_lock);
 501                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
 502                                                    " (too many links)");
 503         }
 504         spin_unlock_bh(&tn->node_list_lock);
 505
 506         buf = tipc_cfg_reply_alloc(payload_size);
 507         if (!buf)
 508                 return NULL;
 509
 510         /* Add TLV for broadcast link */
 511         link_info.dest = htonl(tipc_cluster_mask(tn->own_addr));
 512         link_info.up = htonl(1);
 513         strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
 514         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
 515
 516         /* Add TLVs for any other links in scope */
 517         rcu_read_lock();
 518         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
 519                 u32 i;
 520
 521                 if (!tipc_in_scope(domain, n_ptr->addr))
 522                         continue;
 523                 tipc_node_lock(n_ptr);
 524                 for (i = 0; i < MAX_BEARERS; i++) {
 525                         if (!n_ptr->links[i])
 526                                 continue;
 527                         link_info.dest = htonl(n_ptr->addr);
 528                         link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
 529                         strcpy(link_info.str, n_ptr->links[i]->name);
 530                         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
 531                                             &link_info, sizeof(link_info));
 532                 }
 533                 tipc_node_unlock(n_ptr);
 534         }
 535         rcu_read_unlock();
 536         return buf;
 537 }
 538
 539 /**
 540  * tipc_node_get_linkname - get the name of a link
 541  *
 542  * @bearer_id: id of the bearer
 543  * @node: peer node address
 544  * @linkname: link name output buffer
 545  *
 546  * Returns 0 on success
 547  */
 548 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
 549                            char *linkname, size_t len)
 550 {
 551         struct tipc_link *link;
 552         struct tipc_node *node = tipc_node_find(net, addr);
 553
 554         if ((bearer_id >= MAX_BEARERS) || !node)
 555                 return -EINVAL;
 556         tipc_node_lock(node);
 557         link = node->links[bearer_id];
 558         if (link) {
 559                 strncpy(linkname, link->name, len);
 560                 tipc_node_unlock(node);
 561                 return 0;
 562         }
 563         tipc_node_unlock(node);
 564         return -EINVAL;
 565 }
 566
 567 void tipc_node_unlock(struct tipc_node *node)
 568 {
 569         struct net *net = node->net;
 570         LIST_HEAD(nsub_list);
 571         LIST_HEAD(conn_sks);
 572         struct sk_buff_head waiting_sks;
 573         u32 addr = 0;
 574         int flags = node->action_flags;
 575         u32 link_id = 0;
 576
 577         if (likely(!flags)) {
 578                 spin_unlock_bh(&node->lock);
 579                 return;
 580         }
 581
 582         addr = node->addr;
 583         link_id = node->link_id;
 584         __skb_queue_head_init(&waiting_sks);
 585
 586         if (flags & TIPC_WAKEUP_USERS)
 587                 skb_queue_splice_init(&node->waiting_sks, &waiting_sks);
 588
 589         if (flags & TIPC_NOTIFY_NODE_DOWN) {
 590                 list_replace_init(&node->publ_list, &nsub_list);
 591                 list_replace_init(&node->conn_sks, &conn_sks);
 592         }
 593         node->action_flags &= ~(TIPC_WAKEUP_USERS | TIPC_NOTIFY_NODE_DOWN |
 594                                 TIPC_NOTIFY_NODE_UP | TIPC_NOTIFY_LINK_UP |
 595                                 TIPC_NOTIFY_LINK_DOWN |
 596                                 TIPC_WAKEUP_BCAST_USERS);
 597
 598         spin_unlock_bh(&node->lock);
 599
 600         while (!skb_queue_empty(&waiting_sks))
 601                 tipc_sk_rcv(net, __skb_dequeue(&waiting_sks));
 602
 603         if (!list_empty(&conn_sks))
 604                 tipc_node_abort_sock_conns(net, &conn_sks);
 605
 606         if (!list_empty(&nsub_list))
 607                 tipc_publ_notify(net, &nsub_list, addr);
 608
 609         if (flags & TIPC_WAKEUP_BCAST_USERS)
 610                 tipc_bclink_wakeup_users(net);
 611
 612         if (flags & TIPC_NOTIFY_NODE_UP)
 613                 tipc_named_node_up(net, addr);
 614
 615         if (flags & TIPC_NOTIFY_LINK_UP)
 616                 tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr,
 617                                      TIPC_NODE_SCOPE, link_id, addr);
 618
 619         if (flags & TIPC_NOTIFY_LINK_DOWN)
 620                 tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
 621                                       link_id, addr);
 622 }
 623
 624 /* Caller should hold node lock for the passed node */
 625 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
 626 {
 627         void *hdr;
 628         struct nlattr *attrs;
 629
 630         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_v2_family,
 631                           NLM_F_MULTI, TIPC_NL_NODE_GET);
 632         if (!hdr)
 633                 return -EMSGSIZE;
 634
 635         attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE);
 636         if (!attrs)
 637                 goto msg_full;
 638
 639         if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
 640                 goto attr_msg_full;
 641         if (tipc_node_is_up(node))
 642                 if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
 643                         goto attr_msg_full;
 644
 645         nla_nest_end(msg->skb, attrs);
 646         genlmsg_end(msg->skb, hdr);
 647
 648         return 0;
 649
 650 attr_msg_full:
 651         nla_nest_cancel(msg->skb, attrs);
 652 msg_full:
 653         genlmsg_cancel(msg->skb, hdr);
 654
 655         return -EMSGSIZE;
 656 }
 657
 658 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
 659 {
 660         int err;
 661         struct net *net = sock_net(skb->sk);
 662         struct tipc_net *tn = net_generic(net, tipc_net_id);
 663         int done = cb->args[0];
 664         int last_addr = cb->args[1];
 665         struct tipc_node *node;
 666         struct tipc_nl_msg msg;
 667
 668         if (done)
 669                 return 0;
 670
 671         msg.skb = skb;
 672         msg.portid = NETLINK_CB(cb->skb).portid;
 673         msg.seq = cb->nlh->nlmsg_seq;
 674
 675         rcu_read_lock();
 676
 677         if (last_addr && !tipc_node_find(net, last_addr)) {
 678                 rcu_read_unlock();
 679                 /* We never set seq or call nl_dump_check_consistent() this
 680                  * means that setting prev_seq here will cause the consistence
 681                  * check to fail in the netlink callback handler. Resulting in
 682                  * the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if
 683                  * the node state changed while we released the lock.
 684                  */
 685                 cb->prev_seq = 1;
 686                 return -EPIPE;
 687         }
 688
 689         list_for_each_entry_rcu(node, &tn->node_list, list) {
 690                 if (last_addr) {
 691                         if (node->addr == last_addr)
 692                                 last_addr = 0;
 693                         else
 694                                 continue;
 695                 }
 696
 697                 tipc_node_lock(node);
 698                 err = __tipc_nl_add_node(&msg, node);
 699                 if (err) {
 700                         last_addr = node->addr;
 701                         tipc_node_unlock(node);
 702                         goto out;
 703                 }
 704
 705                 tipc_node_unlock(node);
 706         }
 707         done = 1;
 708 out:
 709         cb->args[0] = done;
 710         cb->args[1] = last_addr;
 711         rcu_read_unlock();
 712
 713         return skb->len;
 714 }