net/tipc/name_table.c

   1 /*
   2  * net/tipc/name_table.c: TIPC name table code
   3  *
   4  * Copyright (c) 2000-2006, 2014-2018, Ericsson AB
   5  * Copyright (c) 2004-2008, 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 <net/sock.h>
  38 #include "core.h"
  39 #include "netlink.h"
  40 #include "name_table.h"
  41 #include "name_distr.h"
  42 #include "subscr.h"
  43 #include "bcast.h"
  44 #include "addr.h"
  45 #include "node.h"
  46 #include "group.h"
  47
  48 /**
  49  * struct service_range - container for all bindings of a service range
  50  * @lower: service range lower bound
  51  * @upper: service range upper bound
  52  * @tree_node: member of service range RB tree
  53  * @local_publ: list of identical publications made from this node
  54  *   Used by closest_first lookup and multicast lookup algorithm
  55  * @all_publ: all publications identical to this one, whatever node and scope
  56  *   Used by round-robin lookup algorithm
  57  */
  58 struct service_range {
  59         u32 lower;
  60         u32 upper;
  61         struct rb_node tree_node;
  62         struct list_head local_publ;
  63         struct list_head all_publ;
  64 };
  65
  66 /**
  67  * struct tipc_service - container for all published instances of a service type
  68  * @type: 32 bit 'type' value for service
  69  * @ranges: rb tree containing all service ranges for this service
  70  * @service_list: links to adjacent name ranges in hash chain
  71  * @subscriptions: list of subscriptions for this service type
  72  * @lock: spinlock controlling access to pertaining service ranges/publications
  73  * @rcu: RCU callback head used for deferred freeing
  74  */
  75 struct tipc_service {
  76         u32 type;
  77         struct rb_root ranges;
  78         struct hlist_node service_list;
  79         struct list_head subscriptions;
  80         spinlock_t lock; /* Covers service range list */
  81         struct rcu_head rcu;
  82 };
  83
  84 static int hash(int x)
  85 {
  86         return x & (TIPC_NAMETBL_SIZE - 1);
  87 }
  88
  89 /**
  90  * tipc_publ_create - create a publication structure
  91  */
  92 static struct publication *tipc_publ_create(u32 type, u32 lower, u32 upper,
  93                                             u32 scope, u32 node, u32 port,
  94                                             u32 key)
  95 {
  96         struct publication *publ = kzalloc(sizeof(*publ), GFP_ATOMIC);
  97
  98         if (!publ)
  99                 return NULL;
 100
 101         publ->type = type;
 102         publ->lower = lower;
 103         publ->upper = upper;
 104         publ->scope = scope;
 105         publ->node = node;
 106         publ->port = port;
 107         publ->key = key;
 108         INIT_LIST_HEAD(&publ->binding_sock);
 109         INIT_LIST_HEAD(&publ->binding_node);
 110         INIT_LIST_HEAD(&publ->local_publ);
 111         INIT_LIST_HEAD(&publ->all_publ);
 112         return publ;
 113 }
 114
 115 /**
 116  * tipc_service_create - create a service structure for the specified 'type'
 117  *
 118  * Allocates a single range structure and sets it to all 0's.
 119  */
 120 static struct tipc_service *tipc_service_create(u32 type, struct hlist_head *hd)
 121 {
 122         struct tipc_service *service = kzalloc(sizeof(*service), GFP_ATOMIC);
 123
 124         if (!service) {
 125                 pr_warn("Service creation failed, no memory\n");
 126                 return NULL;
 127         }
 128
 129         spin_lock_init(&service->lock);
 130         service->type = type;
 131         service->ranges = RB_ROOT;
 132         INIT_HLIST_NODE(&service->service_list);
 133         INIT_LIST_HEAD(&service->subscriptions);
 134         hlist_add_head_rcu(&service->service_list, hd);
 135         return service;
 136 }
 137
 138 /**
 139  * tipc_service_first_range - find first service range in tree matching instance
 140  *
 141  * Very time-critical, so binary search through range rb tree
 142  */
 143 static struct service_range *tipc_service_first_range(struct tipc_service *sc,
 144                                                       u32 instance)
 145 {
 146         struct rb_node *n = sc->ranges.rb_node;
 147         struct service_range *sr;
 148
 149         while (n) {
 150                 sr = container_of(n, struct service_range, tree_node);
 151                 if (sr->lower > instance)
 152                         n = n->rb_left;
 153                 else if (sr->upper < instance)
 154                         n = n->rb_right;
 155                 else
 156                         return sr;
 157         }
 158         return NULL;
 159 }
 160
 161 /*  tipc_service_find_range - find service range matching publication parameters
 162  */
 163 static struct service_range *tipc_service_find_range(struct tipc_service *sc,
 164                                                      u32 lower, u32 upper)
 165 {
 166         struct rb_node *n = sc->ranges.rb_node;
 167         struct service_range *sr;
 168
 169         sr = tipc_service_first_range(sc, lower);
 170         if (!sr)
 171                 return NULL;
 172
 173         /* Look for exact match */
 174         for (n = &sr->tree_node; n; n = rb_next(n)) {
 175                 sr = container_of(n, struct service_range, tree_node);
 176                 if (sr->upper == upper)
 177                         break;
 178         }
 179         if (!n || sr->lower != lower || sr->upper != upper)
 180                 return NULL;
 181
 182         return sr;
 183 }
 184
 185 static struct service_range *tipc_service_create_range(struct tipc_service *sc,
 186                                                        u32 lower, u32 upper)
 187 {
 188         struct rb_node **n, *parent = NULL;
 189         struct service_range *sr, *tmp;
 190
 191         n = &sc->ranges.rb_node;
 192         while (*n) {
 193                 tmp = container_of(*n, struct service_range, tree_node);
 194                 parent = *n;
 195                 tmp = container_of(parent, struct service_range, tree_node);
 196                 if (lower < tmp->lower)
 197                         n = &(*n)->rb_left;
 198                 else if (lower > tmp->lower)
 199                         n = &(*n)->rb_right;
 200                 else if (upper < tmp->upper)
 201                         n = &(*n)->rb_left;
 202                 else if (upper > tmp->upper)
 203                         n = &(*n)->rb_right;
 204                 else
 205                         return tmp;
 206         }
 207         sr = kzalloc(sizeof(*sr), GFP_ATOMIC);
 208         if (!sr)
 209                 return NULL;
 210         sr->lower = lower;
 211         sr->upper = upper;
 212         INIT_LIST_HEAD(&sr->local_publ);
 213         INIT_LIST_HEAD(&sr->all_publ);
 214         rb_link_node(&sr->tree_node, parent, n);
 215         rb_insert_color(&sr->tree_node, &sc->ranges);
 216         return sr;
 217 }
 218
 219 static struct publication *tipc_service_insert_publ(struct net *net,
 220                                                     struct tipc_service *sc,
 221                                                     u32 type, u32 lower,
 222                                                     u32 upper, u32 scope,
 223                                                     u32 node, u32 port,
 224                                                     u32 key)
 225 {
 226         struct tipc_subscription *sub, *tmp;
 227         struct service_range *sr;
 228         struct publication *p;
 229         bool first = false;
 230
 231         sr = tipc_service_create_range(sc, lower, upper);
 232         if (!sr)
 233                 goto  err;
 234
 235         first = list_empty(&sr->all_publ);
 236
 237         /* Return if the publication already exists */
 238         list_for_each_entry(p, &sr->all_publ, all_publ) {
 239                 if (p->key == key && (!p->node || p->node == node))
 240                         return NULL;
 241         }
 242
 243         /* Create and insert publication */
 244         p = tipc_publ_create(type, lower, upper, scope, node, port, key);
 245         if (!p)
 246                 goto err;
 247         if (in_own_node(net, node))
 248                 list_add(&p->local_publ, &sr->local_publ);
 249         list_add(&p->all_publ, &sr->all_publ);
 250
 251         /* Any subscriptions waiting for notification?  */
 252         list_for_each_entry_safe(sub, tmp, &sc->subscriptions, service_list) {
 253                 tipc_sub_report_overlap(sub, p->lower, p->upper, TIPC_PUBLISHED,
 254                                         p->port, p->node, p->scope, first);
 255         }
 256         return p;
 257 err:
 258         pr_warn("Failed to bind to %u,%u,%u, no memory\n", type, lower, upper);
 259         return NULL;
 260 }
 261
 262 /**
 263  * tipc_service_remove_publ - remove a publication from a service
 264  */
 265 static struct publication *tipc_service_remove_publ(struct service_range *sr,
 266                                                     u32 node, u32 key)
 267 {
 268         struct publication *p;
 269
 270         list_for_each_entry(p, &sr->all_publ, all_publ) {
 271                 if (p->key != key || (node && node != p->node))
 272                         continue;
 273                 list_del(&p->all_publ);
 274                 list_del(&p->local_publ);
 275                 return p;
 276         }
 277         return NULL;
 278 }
 279
 280 /**
 281  * tipc_service_subscribe - attach a subscription, and optionally
 282  * issue the prescribed number of events if there is any service
 283  * range overlapping with the requested range
 284  */
 285 static void tipc_service_subscribe(struct tipc_service *service,
 286                                    struct tipc_subscription *sub)
 287 {
 288         struct tipc_subscr *sb = &sub->evt.s;
 289         struct service_range *sr;
 290         struct tipc_name_seq ns;
 291         struct publication *p;
 292         struct rb_node *n;
 293         bool first;
 294
 295         ns.type = tipc_sub_read(sb, seq.type);
 296         ns.lower = tipc_sub_read(sb, seq.lower);
 297         ns.upper = tipc_sub_read(sb, seq.upper);
 298
 299         tipc_sub_get(sub);
 300         list_add(&sub->service_list, &service->subscriptions);
 301
 302         if (tipc_sub_read(sb, filter) & TIPC_SUB_NO_STATUS)
 303                 return;
 304
 305         for (n = rb_first(&service->ranges); n; n = rb_next(n)) {
 306                 sr = container_of(n, struct service_range, tree_node);
 307                 if (sr->lower > ns.upper)
 308                         break;
 309                 if (!tipc_sub_check_overlap(&ns, sr->lower, sr->upper))
 310                         continue;
 311                 first = true;
 312
 313                 list_for_each_entry(p, &sr->all_publ, all_publ) {
 314                         tipc_sub_report_overlap(sub, sr->lower, sr->upper,
 315                                                 TIPC_PUBLISHED, p->port,
 316                                                 p->node, p->scope, first);
 317                         first = false;
 318                 }
 319         }
 320 }
 321
 322 static struct tipc_service *tipc_service_find(struct net *net, u32 type)
 323 {
 324         struct name_table *nt = tipc_name_table(net);
 325         struct hlist_head *service_head;
 326         struct tipc_service *service;
 327
 328         service_head = &nt->services[hash(type)];
 329         hlist_for_each_entry_rcu(service, service_head, service_list) {
 330                 if (service->type == type)
 331                         return service;
 332         }
 333         return NULL;
 334 };
 335
 336 struct publication *tipc_nametbl_insert_publ(struct net *net, u32 type,
 337                                              u32 lower, u32 upper,
 338                                              u32 scope, u32 node,
 339                                              u32 port, u32 key)
 340 {
 341         struct name_table *nt = tipc_name_table(net);
 342         struct tipc_service *sc;
 343         struct publication *p;
 344
 345         if (scope > TIPC_NODE_SCOPE || lower > upper) {
 346                 pr_debug("Failed to bind illegal {%u,%u,%u} with scope %u\n",
 347                          type, lower, upper, scope);
 348                 return NULL;
 349         }
 350         sc = tipc_service_find(net, type);
 351         if (!sc)
 352                 sc = tipc_service_create(type, &nt->services[hash(type)]);
 353         if (!sc)
 354                 return NULL;
 355
 356         spin_lock_bh(&sc->lock);
 357         p = tipc_service_insert_publ(net, sc, type, lower, upper,
 358                                      scope, node, port, key);
 359         spin_unlock_bh(&sc->lock);
 360         return p;
 361 }
 362
 363 struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type,
 364                                              u32 lower, u32 upper,
 365                                              u32 node, u32 key)
 366 {
 367         struct tipc_service *sc = tipc_service_find(net, type);
 368         struct tipc_subscription *sub, *tmp;
 369         struct service_range *sr = NULL;
 370         struct publication *p = NULL;
 371         bool last;
 372
 373         if (!sc)
 374                 return NULL;
 375
 376         spin_lock_bh(&sc->lock);
 377         sr = tipc_service_find_range(sc, lower, upper);
 378         if (!sr)
 379                 goto exit;
 380         p = tipc_service_remove_publ(sr, node, key);
 381         if (!p)
 382                 goto exit;
 383
 384         /* Notify any waiting subscriptions */
 385         last = list_empty(&sr->all_publ);
 386         list_for_each_entry_safe(sub, tmp, &sc->subscriptions, service_list) {
 387                 tipc_sub_report_overlap(sub, lower, upper, TIPC_WITHDRAWN,
 388                                         p->port, node, p->scope, last);
 389         }
 390
 391         /* Remove service range item if this was its last publication */
 392         if (list_empty(&sr->all_publ)) {
 393                 rb_erase(&sr->tree_node, &sc->ranges);
 394                 kfree(sr);
 395         }
 396
 397         /* Delete service item if this no more publications and subscriptions */
 398         if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) {
 399                 hlist_del_init_rcu(&sc->service_list);
 400                 kfree_rcu(sc, rcu);
 401         }
 402 exit:
 403         spin_unlock_bh(&sc->lock);
 404         return p;
 405 }
 406
 407 /**
 408  * tipc_nametbl_translate - perform service instance to socket translation
 409  *
 410  * On entry, 'dnode' is the search domain used during translation.
 411  *
 412  * On exit:
 413  * - if translation is deferred to another node, leave 'dnode' unchanged and
 414  *   return 0
 415  * - if translation is attempted and succeeds, set 'dnode' to the publishing
 416  *   node and return the published (non-zero) port number
 417  * - if translation is attempted and fails, set 'dnode' to 0 and return 0
 418  *
 419  * Note that for legacy users (node configured with Z.C.N address format) the
 420  * 'closest-first' lookup algorithm must be maintained, i.e., if dnode is 0
 421  * we must look in the local binding list first
 422  */
 423 u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance, u32 *dnode)
 424 {
 425         struct tipc_net *tn = tipc_net(net);
 426         bool legacy = tn->legacy_addr_format;
 427         u32 self = tipc_own_addr(net);
 428         struct service_range *sr;
 429         struct tipc_service *sc;
 430         struct list_head *list;
 431         struct publication *p;
 432         u32 port = 0;
 433         u32 node = 0;
 434
 435         if (!tipc_in_scope(legacy, *dnode, self))
 436                 return 0;
 437
 438         rcu_read_lock();
 439         sc = tipc_service_find(net, type);
 440         if (unlikely(!sc))
 441                 goto not_found;
 442
 443         spin_lock_bh(&sc->lock);
 444         sr = tipc_service_first_range(sc, instance);
 445         if (unlikely(!sr))
 446                 goto no_match;
 447
 448         /* Select lookup algorithm: local, closest-first or round-robin */
 449         if (*dnode == self) {
 450                 list = &sr->local_publ;
 451                 if (list_empty(list))
 452                         goto no_match;
 453                 p = list_first_entry(list, struct publication, local_publ);
 454                 list_move_tail(&p->local_publ, &sr->local_publ);
 455         } else if (legacy && !*dnode && !list_empty(&sr->local_publ)) {
 456                 list = &sr->local_publ;
 457                 p = list_first_entry(list, struct publication, local_publ);
 458                 list_move_tail(&p->local_publ, &sr->local_publ);
 459         } else {
 460                 list = &sr->all_publ;
 461                 p = list_first_entry(list, struct publication, all_publ);
 462                 list_move_tail(&p->all_publ, &sr->all_publ);
 463         }
 464         port = p->port;
 465         node = p->node;
 466 no_match:
 467         spin_unlock_bh(&sc->lock);
 468 not_found:
 469         rcu_read_unlock();
 470         *dnode = node;
 471         return port;
 472 }
 473
 474 bool tipc_nametbl_lookup(struct net *net, u32 type, u32 instance, u32 scope,
 475                          struct list_head *dsts, int *dstcnt, u32 exclude,
 476                          bool all)
 477 {
 478         u32 self = tipc_own_addr(net);
 479         struct service_range *sr;
 480         struct tipc_service *sc;
 481         struct publication *p;
 482
 483         *dstcnt = 0;
 484         rcu_read_lock();
 485         sc = tipc_service_find(net, type);
 486         if (unlikely(!sc))
 487                 goto exit;
 488
 489         spin_lock_bh(&sc->lock);
 490
 491         sr = tipc_service_first_range(sc, instance);
 492         if (!sr)
 493                 goto no_match;
 494
 495         list_for_each_entry(p, &sr->all_publ, all_publ) {
 496                 if (p->scope != scope)
 497                         continue;
 498                 if (p->port == exclude && p->node == self)
 499                         continue;
 500                 tipc_dest_push(dsts, p->node, p->port);
 501                 (*dstcnt)++;
 502                 if (all)
 503                         continue;
 504                 list_move_tail(&p->all_publ, &sr->all_publ);
 505                 break;
 506         }
 507 no_match:
 508         spin_unlock_bh(&sc->lock);
 509 exit:
 510         rcu_read_unlock();
 511         return !list_empty(dsts);
 512 }
 513
 514 void tipc_nametbl_mc_lookup(struct net *net, u32 type, u32 lower, u32 upper,
 515                             u32 scope, bool exact, struct list_head *dports)
 516 {
 517         struct service_range *sr;
 518         struct tipc_service *sc;
 519         struct publication *p;
 520         struct rb_node *n;
 521
 522         rcu_read_lock();
 523         sc = tipc_service_find(net, type);
 524         if (!sc)
 525                 goto exit;
 526
 527         spin_lock_bh(&sc->lock);
 528
 529         for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 530                 sr = container_of(n, struct service_range, tree_node);
 531                 if (sr->upper < lower)
 532                         continue;
 533                 if (sr->lower > upper)
 534                         break;
 535                 list_for_each_entry(p, &sr->local_publ, local_publ) {
 536                         if (p->scope == scope || (!exact && p->scope < scope))
 537                                 tipc_dest_push(dports, 0, p->port);
 538                 }
 539         }
 540         spin_unlock_bh(&sc->lock);
 541 exit:
 542         rcu_read_unlock();
 543 }
 544
 545 /* tipc_nametbl_lookup_dst_nodes - find broadcast destination nodes
 546  * - Creates list of nodes that overlap the given multicast address
 547  * - Determines if any node local destinations overlap
 548  */
 549 void tipc_nametbl_lookup_dst_nodes(struct net *net, u32 type, u32 lower,
 550                                    u32 upper, struct tipc_nlist *nodes)
 551 {
 552         struct service_range *sr;
 553         struct tipc_service *sc;
 554         struct publication *p;
 555         struct rb_node *n;
 556
 557         rcu_read_lock();
 558         sc = tipc_service_find(net, type);
 559         if (!sc)
 560                 goto exit;
 561
 562         spin_lock_bh(&sc->lock);
 563
 564         for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 565                 sr = container_of(n, struct service_range, tree_node);
 566                 if (sr->upper < lower)
 567                         continue;
 568                 if (sr->lower > upper)
 569                         break;
 570                 list_for_each_entry(p, &sr->all_publ, all_publ) {
 571                         tipc_nlist_add(nodes, p->node);
 572                 }
 573         }
 574         spin_unlock_bh(&sc->lock);
 575 exit:
 576         rcu_read_unlock();
 577 }
 578
 579 /* tipc_nametbl_build_group - build list of communication group members
 580  */
 581 void tipc_nametbl_build_group(struct net *net, struct tipc_group *grp,
 582                               u32 type, u32 scope)
 583 {
 584         struct service_range *sr;
 585         struct tipc_service *sc;
 586         struct publication *p;
 587         struct rb_node *n;
 588
 589         rcu_read_lock();
 590         sc = tipc_service_find(net, type);
 591         if (!sc)
 592                 goto exit;
 593
 594         spin_lock_bh(&sc->lock);
 595         for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 596                 sr = container_of(n, struct service_range, tree_node);
 597                 list_for_each_entry(p, &sr->all_publ, all_publ) {
 598                         if (p->scope != scope)
 599                                 continue;
 600                         tipc_group_add_member(grp, p->node, p->port, p->lower);
 601                 }
 602         }
 603         spin_unlock_bh(&sc->lock);
 604 exit:
 605         rcu_read_unlock();
 606 }
 607
 608 /* tipc_nametbl_publish - add service binding to name table
 609  */
 610 struct publication *tipc_nametbl_publish(struct net *net, u32 type, u32 lower,
 611                                          u32 upper, u32 scope, u32 port,
 612                                          u32 key)
 613 {
 614         struct name_table *nt = tipc_name_table(net);
 615         struct tipc_net *tn = tipc_net(net);
 616         struct publication *p = NULL;
 617         struct sk_buff *skb = NULL;
 618
 619         spin_lock_bh(&tn->nametbl_lock);
 620
 621         if (nt->local_publ_count >= TIPC_MAX_PUBL) {
 622                 pr_warn("Bind failed, max limit %u reached\n", TIPC_MAX_PUBL);
 623                 goto exit;
 624         }
 625
 626         p = tipc_nametbl_insert_publ(net, type, lower, upper, scope,
 627                                      tipc_own_addr(net), port, key);
 628         if (p) {
 629                 nt->local_publ_count++;
 630                 skb = tipc_named_publish(net, p);
 631         }
 632 exit:
 633         spin_unlock_bh(&tn->nametbl_lock);
 634
 635         if (skb)
 636                 tipc_node_broadcast(net, skb);
 637         return p;
 638 }
 639
 640 /**
 641  * tipc_nametbl_withdraw - withdraw a service binding
 642  */
 643 int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower,
 644                           u32 upper, u32 key)
 645 {
 646         struct name_table *nt = tipc_name_table(net);
 647         struct tipc_net *tn = tipc_net(net);
 648         u32 self = tipc_own_addr(net);
 649         struct sk_buff *skb = NULL;
 650         struct publication *p;
 651
 652         spin_lock_bh(&tn->nametbl_lock);
 653
 654         p = tipc_nametbl_remove_publ(net, type, lower, upper, self, key);
 655         if (p) {
 656                 nt->local_publ_count--;
 657                 skb = tipc_named_withdraw(net, p);
 658                 list_del_init(&p->binding_sock);
 659                 kfree_rcu(p, rcu);
 660         } else {
 661                 pr_err("Failed to remove local publication {%u,%u,%u}/%u\n",
 662                        type, lower, upper, key);
 663         }
 664         spin_unlock_bh(&tn->nametbl_lock);
 665
 666         if (skb) {
 667                 tipc_node_broadcast(net, skb);
 668                 return 1;
 669         }
 670         return 0;
 671 }
 672
 673 /**
 674  * tipc_nametbl_subscribe - add a subscription object to the name table
 675  */
 676 bool tipc_nametbl_subscribe(struct tipc_subscription *sub)
 677 {
 678         struct name_table *nt = tipc_name_table(sub->net);
 679         struct tipc_net *tn = tipc_net(sub->net);
 680         struct tipc_subscr *s = &sub->evt.s;
 681         u32 type = tipc_sub_read(s, seq.type);
 682         struct tipc_service *sc;
 683         bool res = true;
 684
 685         spin_lock_bh(&tn->nametbl_lock);
 686         sc = tipc_service_find(sub->net, type);
 687         if (!sc)
 688                 sc = tipc_service_create(type, &nt->services[hash(type)]);
 689         if (sc) {
 690                 spin_lock_bh(&sc->lock);
 691                 tipc_service_subscribe(sc, sub);
 692                 spin_unlock_bh(&sc->lock);
 693         } else {
 694                 pr_warn("Failed to subscribe for {%u,%u,%u}\n", type,
 695                         tipc_sub_read(s, seq.lower),
 696                         tipc_sub_read(s, seq.upper));
 697                 res = false;
 698         }
 699         spin_unlock_bh(&tn->nametbl_lock);
 700         return res;
 701 }
 702
 703 /**
 704  * tipc_nametbl_unsubscribe - remove a subscription object from name table
 705  */
 706 void tipc_nametbl_unsubscribe(struct tipc_subscription *sub)
 707 {
 708         struct tipc_net *tn = tipc_net(sub->net);
 709         struct tipc_subscr *s = &sub->evt.s;
 710         u32 type = tipc_sub_read(s, seq.type);
 711         struct tipc_service *sc;
 712
 713         spin_lock_bh(&tn->nametbl_lock);
 714         sc = tipc_service_find(sub->net, type);
 715         if (!sc)
 716                 goto exit;
 717
 718         spin_lock_bh(&sc->lock);
 719         list_del_init(&sub->service_list);
 720         tipc_sub_put(sub);
 721
 722         /* Delete service item if no more publications and subscriptions */
 723         if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) {
 724                 hlist_del_init_rcu(&sc->service_list);
 725                 kfree_rcu(sc, rcu);
 726         }
 727         spin_unlock_bh(&sc->lock);
 728 exit:
 729         spin_unlock_bh(&tn->nametbl_lock);
 730 }
 731
 732 int tipc_nametbl_init(struct net *net)
 733 {
 734         struct tipc_net *tn = tipc_net(net);
 735         struct name_table *nt;
 736         int i;
 737
 738         nt = kzalloc(sizeof(*nt), GFP_KERNEL);
 739         if (!nt)
 740                 return -ENOMEM;
 741
 742         for (i = 0; i < TIPC_NAMETBL_SIZE; i++)
 743                 INIT_HLIST_HEAD(&nt->services[i]);
 744
 745         INIT_LIST_HEAD(&nt->node_scope);
 746         INIT_LIST_HEAD(&nt->cluster_scope);
 747         rwlock_init(&nt->cluster_scope_lock);
 748         tn->nametbl = nt;
 749         spin_lock_init(&tn->nametbl_lock);
 750         return 0;
 751 }
 752
 753 /**
 754  *  tipc_service_delete - purge all publications for a service and delete it
 755  */
 756 static void tipc_service_delete(struct net *net, struct tipc_service *sc)
 757 {
 758         struct service_range *sr, *tmpr;
 759         struct publication *p, *tmp;
 760
 761         spin_lock_bh(&sc->lock);
 762         rbtree_postorder_for_each_entry_safe(sr, tmpr, &sc->ranges, tree_node) {
 763                 list_for_each_entry_safe(p, tmp, &sr->all_publ, all_publ) {
 764                         tipc_service_remove_publ(sr, p->node, p->key);
 765                         kfree_rcu(p, rcu);
 766                 }
 767                 rb_erase(&sr->tree_node, &sc->ranges);
 768                 kfree(sr);
 769         }
 770         hlist_del_init_rcu(&sc->service_list);
 771         spin_unlock_bh(&sc->lock);
 772         kfree_rcu(sc, rcu);
 773 }
 774
 775 void tipc_nametbl_stop(struct net *net)
 776 {
 777         struct name_table *nt = tipc_name_table(net);
 778         struct tipc_net *tn = tipc_net(net);
 779         struct hlist_head *service_head;
 780         struct tipc_service *service;
 781         u32 i;
 782
 783         /* Verify name table is empty and purge any lingering
 784          * publications, then release the name table
 785          */
 786         spin_lock_bh(&tn->nametbl_lock);
 787         for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
 788                 if (hlist_empty(&nt->services[i]))
 789                         continue;
 790                 service_head = &nt->services[i];
 791                 hlist_for_each_entry_rcu(service, service_head, service_list) {
 792                         tipc_service_delete(net, service);
 793                 }
 794         }
 795         spin_unlock_bh(&tn->nametbl_lock);
 796
 797         synchronize_net();
 798         kfree(nt);
 799 }
 800
 801 static int __tipc_nl_add_nametable_publ(struct tipc_nl_msg *msg,
 802                                         struct tipc_service *service,
 803                                         struct service_range *sr,
 804                                         u32 *last_key)
 805 {
 806         struct publication *p;
 807         struct nlattr *attrs;
 808         struct nlattr *b;
 809         void *hdr;
 810
 811         if (*last_key) {
 812                 list_for_each_entry(p, &sr->all_publ, all_publ)
 813                         if (p->key == *last_key)
 814                                 break;
 815                 if (p->key != *last_key)
 816                         return -EPIPE;
 817         } else {
 818                 p = list_first_entry(&sr->all_publ,
 819                                      struct publication,
 820                                      all_publ);
 821         }
 822
 823         list_for_each_entry_from(p, &sr->all_publ, all_publ) {
 824                 *last_key = p->key;
 825
 826                 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq,
 827                                   &tipc_genl_family, NLM_F_MULTI,
 828                                   TIPC_NL_NAME_TABLE_GET);
 829                 if (!hdr)
 830                         return -EMSGSIZE;
 831
 832                 attrs = nla_nest_start(msg->skb, TIPC_NLA_NAME_TABLE);
 833                 if (!attrs)
 834                         goto msg_full;
 835
 836                 b = nla_nest_start(msg->skb, TIPC_NLA_NAME_TABLE_PUBL);
 837                 if (!b)
 838                         goto attr_msg_full;
 839
 840                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_TYPE, service->type))
 841                         goto publ_msg_full;
 842                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_LOWER, sr->lower))
 843                         goto publ_msg_full;
 844                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_UPPER, sr->upper))
 845                         goto publ_msg_full;
 846                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_SCOPE, p->scope))
 847                         goto publ_msg_full;
 848                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_NODE, p->node))
 849                         goto publ_msg_full;
 850                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_REF, p->port))
 851                         goto publ_msg_full;
 852                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_KEY, p->key))
 853                         goto publ_msg_full;
 854
 855                 nla_nest_end(msg->skb, b);
 856                 nla_nest_end(msg->skb, attrs);
 857                 genlmsg_end(msg->skb, hdr);
 858         }
 859         *last_key = 0;
 860
 861         return 0;
 862
 863 publ_msg_full:
 864         nla_nest_cancel(msg->skb, b);
 865 attr_msg_full:
 866         nla_nest_cancel(msg->skb, attrs);
 867 msg_full:
 868         genlmsg_cancel(msg->skb, hdr);
 869
 870         return -EMSGSIZE;
 871 }
 872
 873 static int __tipc_nl_service_range_list(struct tipc_nl_msg *msg,
 874                                         struct tipc_service *sc,
 875                                         u32 *last_lower, u32 *last_key)
 876 {
 877         struct service_range *sr;
 878         struct rb_node *n;
 879         int err;
 880
 881         for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 882                 sr = container_of(n, struct service_range, tree_node);
 883                 if (sr->lower < *last_lower)
 884                         continue;
 885                 err = __tipc_nl_add_nametable_publ(msg, sc, sr, last_key);
 886                 if (err) {
 887                         *last_lower = sr->lower;
 888                         return err;
 889                 }
 890         }
 891         *last_lower = 0;
 892         return 0;
 893 }
 894
 895 static int tipc_nl_service_list(struct net *net, struct tipc_nl_msg *msg,
 896                                 u32 *last_type, u32 *last_lower, u32 *last_key)
 897 {
 898         struct tipc_net *tn = tipc_net(net);
 899         struct tipc_service *service = NULL;
 900         struct hlist_head *head;
 901         int err;
 902         int i;
 903
 904         if (*last_type)
 905                 i = hash(*last_type);
 906         else
 907                 i = 0;
 908
 909         for (; i < TIPC_NAMETBL_SIZE; i++) {
 910                 head = &tn->nametbl->services[i];
 911
 912                 if (*last_type ||
 913                     (!i && *last_key && (*last_lower == *last_key))) {
 914                         service = tipc_service_find(net, *last_type);
 915                         if (!service)
 916                                 return -EPIPE;
 917                 } else {
 918                         hlist_for_each_entry_rcu(service, head, service_list)
 919                                 break;
 920                         if (!service)
 921                                 continue;
 922                 }
 923
 924                 hlist_for_each_entry_from_rcu(service, service_list) {
 925                         spin_lock_bh(&service->lock);
 926                         err = __tipc_nl_service_range_list(msg, service,
 927                                                            last_lower,
 928                                                            last_key);
 929
 930                         if (err) {
 931                                 *last_type = service->type;
 932                                 spin_unlock_bh(&service->lock);
 933                                 return err;
 934                         }
 935                         spin_unlock_bh(&service->lock);
 936                 }
 937                 *last_type = 0;
 938         }
 939         return 0;
 940 }
 941
 942 int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
 943 {
 944         struct net *net = sock_net(skb->sk);
 945         u32 last_type = cb->args[0];
 946         u32 last_lower = cb->args[1];
 947         u32 last_key = cb->args[2];
 948         int done = cb->args[3];
 949         struct tipc_nl_msg msg;
 950         int err;
 951
 952         if (done)
 953                 return 0;
 954
 955         msg.skb = skb;
 956         msg.portid = NETLINK_CB(cb->skb).portid;
 957         msg.seq = cb->nlh->nlmsg_seq;
 958
 959         rcu_read_lock();
 960         err = tipc_nl_service_list(net, &msg, &last_type,
 961                                    &last_lower, &last_key);
 962         if (!err) {
 963                 done = 1;
 964         } else if (err != -EMSGSIZE) {
 965                 /* We never set seq or call nl_dump_check_consistent() this
 966                  * means that setting prev_seq here will cause the consistence
 967                  * check to fail in the netlink callback handler. Resulting in
 968                  * the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if
 969                  * we got an error.
 970                  */
 971                 cb->prev_seq = 1;
 972         }
 973         rcu_read_unlock();
 974
 975         cb->args[0] = last_type;
 976         cb->args[1] = last_lower;
 977         cb->args[2] = last_key;
 978         cb->args[3] = done;
 979
 980         return skb->len;
 981 }
 982
 983 struct tipc_dest *tipc_dest_find(struct list_head *l, u32 node, u32 port)
 984 {
 985         struct tipc_dest *dst;
 986
 987         list_for_each_entry(dst, l, list) {
 988                 if (dst->node == node && dst->port == port)
 989                         return dst;
 990         }
 991         return NULL;
 992 }
 993
 994 bool tipc_dest_push(struct list_head *l, u32 node, u32 port)
 995 {
 996         struct tipc_dest *dst;
 997
 998         if (tipc_dest_find(l, node, port))
 999                 return false;
1000
1001         dst = kmalloc(sizeof(*dst), GFP_ATOMIC);
1002         if (unlikely(!dst))
1003                 return false;
1004         dst->node = node;
1005         dst->port = port;
1006         list_add(&dst->list, l);
1007         return true;
1008 }
1009
1010 bool tipc_dest_pop(struct list_head *l, u32 *node, u32 *port)
1011 {
1012         struct tipc_dest *dst;
1013
1014         if (list_empty(l))
1015                 return false;
1016         dst = list_first_entry(l, typeof(*dst), list);
1017         if (port)
1018                 *port = dst->port;
1019         if (node)
1020                 *node = dst->node;
1021         list_del(&dst->list);
1022         kfree(dst);
1023         return true;
1024 }
1025
1026 bool tipc_dest_del(struct list_head *l, u32 node, u32 port)
1027 {
1028         struct tipc_dest *dst;
1029
1030         dst = tipc_dest_find(l, node, port);
1031         if (!dst)
1032                 return false;
1033         list_del(&dst->list);
1034         kfree(dst);
1035         return true;
1036 }
1037
1038 void tipc_dest_list_purge(struct list_head *l)
1039 {
1040         struct tipc_dest *dst, *tmp;
1041
1042         list_for_each_entry_safe(dst, tmp, l, list) {
1043                 list_del(&dst->list);
1044                 kfree(dst);
1045         }
1046 }
1047
1048 int tipc_dest_list_len(struct list_head *l)
1049 {
1050         struct tipc_dest *dst;
1051         int i = 0;
1052
1053         list_for_each_entry(dst, l, list) {
1054                 i++;
1055         }
1056         return i;
1057 }