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