net/tipc/name_table.c

   1 /*
   2  * net/tipc/name_table.c: TIPC name table code
   3  *
   4  * Copyright (c) 2000-2006, 2014, 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 "core.h"
  38 #include "config.h"
  39 #include "name_table.h"
  40 #include "name_distr.h"
  41 #include "subscr.h"
  42
  43 #define TIPC_NAMETBL_SIZE 1024          /* must be a power of 2 */
  44
  45 static const struct nla_policy
  46 tipc_nl_name_table_policy[TIPC_NLA_NAME_TABLE_MAX + 1] = {
  47         [TIPC_NLA_NAME_TABLE_UNSPEC]    = { .type = NLA_UNSPEC },
  48         [TIPC_NLA_NAME_TABLE_PUBL]      = { .type = NLA_NESTED }
  49 };
  50
  51 /**
  52  * struct name_info - name sequence publication info
  53  * @node_list: circular list of publications made by own node
  54  * @cluster_list: circular list of publications made by own cluster
  55  * @zone_list: circular list of publications made by own zone
  56  * @node_list_size: number of entries in "node_list"
  57  * @cluster_list_size: number of entries in "cluster_list"
  58  * @zone_list_size: number of entries in "zone_list"
  59  *
  60  * Note: The zone list always contains at least one entry, since all
  61  *       publications of the associated name sequence belong to it.
  62  *       (The cluster and node lists may be empty.)
  63  */
  64 struct name_info {
  65         struct list_head node_list;
  66         struct list_head cluster_list;
  67         struct list_head zone_list;
  68         u32 node_list_size;
  69         u32 cluster_list_size;
  70         u32 zone_list_size;
  71 };
  72
  73 /**
  74  * struct sub_seq - container for all published instances of a name sequence
  75  * @lower: name sequence lower bound
  76  * @upper: name sequence upper bound
  77  * @info: pointer to name sequence publication info
  78  */
  79 struct sub_seq {
  80         u32 lower;
  81         u32 upper;
  82         struct name_info *info;
  83 };
  84
  85 /**
  86  * struct name_seq - container for all published instances of a name type
  87  * @type: 32 bit 'type' value for name sequence
  88  * @sseq: pointer to dynamically-sized array of sub-sequences of this 'type';
  89  *        sub-sequences are sorted in ascending order
  90  * @alloc: number of sub-sequences currently in array
  91  * @first_free: array index of first unused sub-sequence entry
  92  * @ns_list: links to adjacent name sequences in hash chain
  93  * @subscriptions: list of subscriptions for this 'type'
  94  * @lock: spinlock controlling access to publication lists of all sub-sequences
  95  * @rcu: RCU callback head used for deferred freeing
  96  */
  97 struct name_seq {
  98         u32 type;
  99         struct sub_seq *sseqs;
 100         u32 alloc;
 101         u32 first_free;
 102         struct hlist_node ns_list;
 103         struct list_head subscriptions;
 104         spinlock_t lock;
 105         struct rcu_head rcu;
 106 };
 107
 108 struct name_table *tipc_nametbl;
 109 DEFINE_SPINLOCK(tipc_nametbl_lock);
 110
 111 static int hash(int x)
 112 {
 113         return x & (TIPC_NAMETBL_SIZE - 1);
 114 }
 115
 116 /**
 117  * publ_create - create a publication structure
 118  */
 119 static struct publication *publ_create(u32 type, u32 lower, u32 upper,
 120                                        u32 scope, u32 node, u32 port_ref,
 121                                        u32 key)
 122 {
 123         struct publication *publ = kzalloc(sizeof(*publ), GFP_ATOMIC);
 124         if (publ == NULL) {
 125                 pr_warn("Publication creation failure, no memory\n");
 126                 return NULL;
 127         }
 128
 129         publ->type = type;
 130         publ->lower = lower;
 131         publ->upper = upper;
 132         publ->scope = scope;
 133         publ->node = node;
 134         publ->ref = port_ref;
 135         publ->key = key;
 136         INIT_LIST_HEAD(&publ->pport_list);
 137         return publ;
 138 }
 139
 140 /**
 141  * tipc_subseq_alloc - allocate a specified number of sub-sequence structures
 142  */
 143 static struct sub_seq *tipc_subseq_alloc(u32 cnt)
 144 {
 145         return kcalloc(cnt, sizeof(struct sub_seq), GFP_ATOMIC);
 146 }
 147
 148 /**
 149  * tipc_nameseq_create - create a name sequence structure for the specified 'type'
 150  *
 151  * Allocates a single sub-sequence structure and sets it to all 0's.
 152  */
 153 static struct name_seq *tipc_nameseq_create(u32 type, struct hlist_head *seq_head)
 154 {
 155         struct name_seq *nseq = kzalloc(sizeof(*nseq), GFP_ATOMIC);
 156         struct sub_seq *sseq = tipc_subseq_alloc(1);
 157
 158         if (!nseq || !sseq) {
 159                 pr_warn("Name sequence creation failed, no memory\n");
 160                 kfree(nseq);
 161                 kfree(sseq);
 162                 return NULL;
 163         }
 164
 165         spin_lock_init(&nseq->lock);
 166         nseq->type = type;
 167         nseq->sseqs = sseq;
 168         nseq->alloc = 1;
 169         INIT_HLIST_NODE(&nseq->ns_list);
 170         INIT_LIST_HEAD(&nseq->subscriptions);
 171         hlist_add_head_rcu(&nseq->ns_list, seq_head);
 172         return nseq;
 173 }
 174
 175 /**
 176  * nameseq_find_subseq - find sub-sequence (if any) matching a name instance
 177  *
 178  * Very time-critical, so binary searches through sub-sequence array.
 179  */
 180 static struct sub_seq *nameseq_find_subseq(struct name_seq *nseq,
 181                                            u32 instance)
 182 {
 183         struct sub_seq *sseqs = nseq->sseqs;
 184         int low = 0;
 185         int high = nseq->first_free - 1;
 186         int mid;
 187
 188         while (low <= high) {
 189                 mid = (low + high) / 2;
 190                 if (instance < sseqs[mid].lower)
 191                         high = mid - 1;
 192                 else if (instance > sseqs[mid].upper)
 193                         low = mid + 1;
 194                 else
 195                         return &sseqs[mid];
 196         }
 197         return NULL;
 198 }
 199
 200 /**
 201  * nameseq_locate_subseq - determine position of name instance in sub-sequence
 202  *
 203  * Returns index in sub-sequence array of the entry that contains the specified
 204  * instance value; if no entry contains that value, returns the position
 205  * where a new entry for it would be inserted in the array.
 206  *
 207  * Note: Similar to binary search code for locating a sub-sequence.
 208  */
 209 static u32 nameseq_locate_subseq(struct name_seq *nseq, u32 instance)
 210 {
 211         struct sub_seq *sseqs = nseq->sseqs;
 212         int low = 0;
 213         int high = nseq->first_free - 1;
 214         int mid;
 215
 216         while (low <= high) {
 217                 mid = (low + high) / 2;
 218                 if (instance < sseqs[mid].lower)
 219                         high = mid - 1;
 220                 else if (instance > sseqs[mid].upper)
 221                         low = mid + 1;
 222                 else
 223                         return mid;
 224         }
 225         return low;
 226 }
 227
 228 /**
 229  * tipc_nameseq_insert_publ
 230  */
 231 static struct publication *tipc_nameseq_insert_publ(struct name_seq *nseq,
 232                                                     u32 type, u32 lower, u32 upper,
 233                                                     u32 scope, u32 node, u32 port, u32 key)
 234 {
 235         struct tipc_subscription *s;
 236         struct tipc_subscription *st;
 237         struct publication *publ;
 238         struct sub_seq *sseq;
 239         struct name_info *info;
 240         int created_subseq = 0;
 241
 242         sseq = nameseq_find_subseq(nseq, lower);
 243         if (sseq) {
 244
 245                 /* Lower end overlaps existing entry => need an exact match */
 246                 if ((sseq->lower != lower) || (sseq->upper != upper)) {
 247                         return NULL;
 248                 }
 249
 250                 info = sseq->info;
 251
 252                 /* Check if an identical publication already exists */
 253                 list_for_each_entry(publ, &info->zone_list, zone_list) {
 254                         if ((publ->ref == port) && (publ->key == key) &&
 255                             (!publ->node || (publ->node == node)))
 256                                 return NULL;
 257                 }
 258         } else {
 259                 u32 inspos;
 260                 struct sub_seq *freesseq;
 261
 262                 /* Find where lower end should be inserted */
 263                 inspos = nameseq_locate_subseq(nseq, lower);
 264
 265                 /* Fail if upper end overlaps into an existing entry */
 266                 if ((inspos < nseq->first_free) &&
 267                     (upper >= nseq->sseqs[inspos].lower)) {
 268                         return NULL;
 269                 }
 270
 271                 /* Ensure there is space for new sub-sequence */
 272                 if (nseq->first_free == nseq->alloc) {
 273                         struct sub_seq *sseqs = tipc_subseq_alloc(nseq->alloc * 2);
 274
 275                         if (!sseqs) {
 276                                 pr_warn("Cannot publish {%u,%u,%u}, no memory\n",
 277                                         type, lower, upper);
 278                                 return NULL;
 279                         }
 280                         memcpy(sseqs, nseq->sseqs,
 281                                nseq->alloc * sizeof(struct sub_seq));
 282                         kfree(nseq->sseqs);
 283                         nseq->sseqs = sseqs;
 284                         nseq->alloc *= 2;
 285                 }
 286
 287                 info = kzalloc(sizeof(*info), GFP_ATOMIC);
 288                 if (!info) {
 289                         pr_warn("Cannot publish {%u,%u,%u}, no memory\n",
 290                                 type, lower, upper);
 291                         return NULL;
 292                 }
 293
 294                 INIT_LIST_HEAD(&info->node_list);
 295                 INIT_LIST_HEAD(&info->cluster_list);
 296                 INIT_LIST_HEAD(&info->zone_list);
 297
 298                 /* Insert new sub-sequence */
 299                 sseq = &nseq->sseqs[inspos];
 300                 freesseq = &nseq->sseqs[nseq->first_free];
 301                 memmove(sseq + 1, sseq, (freesseq - sseq) * sizeof(*sseq));
 302                 memset(sseq, 0, sizeof(*sseq));
 303                 nseq->first_free++;
 304                 sseq->lower = lower;
 305                 sseq->upper = upper;
 306                 sseq->info = info;
 307                 created_subseq = 1;
 308         }
 309
 310         /* Insert a publication */
 311         publ = publ_create(type, lower, upper, scope, node, port, key);
 312         if (!publ)
 313                 return NULL;
 314
 315         list_add(&publ->zone_list, &info->zone_list);
 316         info->zone_list_size++;
 317
 318         if (in_own_cluster(node)) {
 319                 list_add(&publ->cluster_list, &info->cluster_list);
 320                 info->cluster_list_size++;
 321         }
 322
 323         if (in_own_node(node)) {
 324                 list_add(&publ->node_list, &info->node_list);
 325                 info->node_list_size++;
 326         }
 327
 328         /* Any subscriptions waiting for notification?  */
 329         list_for_each_entry_safe(s, st, &nseq->subscriptions, nameseq_list) {
 330                 tipc_subscr_report_overlap(s,
 331                                            publ->lower,
 332                                            publ->upper,
 333                                            TIPC_PUBLISHED,
 334                                            publ->ref,
 335                                            publ->node,
 336                                            created_subseq);
 337         }
 338         return publ;
 339 }
 340
 341 /**
 342  * tipc_nameseq_remove_publ
 343  *
 344  * NOTE: There may be cases where TIPC is asked to remove a publication
 345  * that is not in the name table.  For example, if another node issues a
 346  * publication for a name sequence that overlaps an existing name sequence
 347  * the publication will not be recorded, which means the publication won't
 348  * be found when the name sequence is later withdrawn by that node.
 349  * A failed withdraw request simply returns a failure indication and lets the
 350  * caller issue any error or warning messages associated with such a problem.
 351  */
 352 static struct publication *tipc_nameseq_remove_publ(struct name_seq *nseq, u32 inst,
 353                                                     u32 node, u32 ref, u32 key)
 354 {
 355         struct publication *publ;
 356         struct sub_seq *sseq = nameseq_find_subseq(nseq, inst);
 357         struct name_info *info;
 358         struct sub_seq *free;
 359         struct tipc_subscription *s, *st;
 360         int removed_subseq = 0;
 361
 362         if (!sseq)
 363                 return NULL;
 364
 365         info = sseq->info;
 366
 367         /* Locate publication, if it exists */
 368         list_for_each_entry(publ, &info->zone_list, zone_list) {
 369                 if ((publ->key == key) && (publ->ref == ref) &&
 370                     (!publ->node || (publ->node == node)))
 371                         goto found;
 372         }
 373         return NULL;
 374
 375 found:
 376         /* Remove publication from zone scope list */
 377         list_del(&publ->zone_list);
 378         info->zone_list_size--;
 379
 380         /* Remove publication from cluster scope list, if present */
 381         if (in_own_cluster(node)) {
 382                 list_del(&publ->cluster_list);
 383                 info->cluster_list_size--;
 384         }
 385
 386         /* Remove publication from node scope list, if present */
 387         if (in_own_node(node)) {
 388                 list_del(&publ->node_list);
 389                 info->node_list_size--;
 390         }
 391
 392         /* Contract subseq list if no more publications for that subseq */
 393         if (list_empty(&info->zone_list)) {
 394                 kfree(info);
 395                 free = &nseq->sseqs[nseq->first_free--];
 396                 memmove(sseq, sseq + 1, (free - (sseq + 1)) * sizeof(*sseq));
 397                 removed_subseq = 1;
 398         }
 399
 400         /* Notify any waiting subscriptions */
 401         list_for_each_entry_safe(s, st, &nseq->subscriptions, nameseq_list) {
 402                 tipc_subscr_report_overlap(s,
 403                                            publ->lower,
 404                                            publ->upper,
 405                                            TIPC_WITHDRAWN,
 406                                            publ->ref,
 407                                            publ->node,
 408                                            removed_subseq);
 409         }
 410
 411         return publ;
 412 }
 413
 414 /**
 415  * tipc_nameseq_subscribe - attach a subscription, and issue
 416  * the prescribed number of events if there is any sub-
 417  * sequence overlapping with the requested sequence
 418  */
 419 static void tipc_nameseq_subscribe(struct name_seq *nseq,
 420                                    struct tipc_subscription *s)
 421 {
 422         struct sub_seq *sseq = nseq->sseqs;
 423
 424         list_add(&s->nameseq_list, &nseq->subscriptions);
 425
 426         if (!sseq)
 427                 return;
 428
 429         while (sseq != &nseq->sseqs[nseq->first_free]) {
 430                 if (tipc_subscr_overlap(s, sseq->lower, sseq->upper)) {
 431                         struct publication *crs;
 432                         struct name_info *info = sseq->info;
 433                         int must_report = 1;
 434
 435                         list_for_each_entry(crs, &info->zone_list, zone_list) {
 436                                 tipc_subscr_report_overlap(s,
 437                                                            sseq->lower,
 438                                                            sseq->upper,
 439                                                            TIPC_PUBLISHED,
 440                                                            crs->ref,
 441                                                            crs->node,
 442                                                            must_report);
 443                                 must_report = 0;
 444                         }
 445                 }
 446                 sseq++;
 447         }
 448 }
 449
 450 static struct name_seq *nametbl_find_seq(u32 type)
 451 {
 452         struct hlist_head *seq_head;
 453         struct name_seq *ns;
 454
 455         seq_head = &tipc_nametbl->seq_hlist[hash(type)];
 456         hlist_for_each_entry_rcu(ns, seq_head, ns_list) {
 457                 if (ns->type == type)
 458                         return ns;
 459         }
 460
 461         return NULL;
 462 };
 463
 464 struct publication *tipc_nametbl_insert_publ(u32 type, u32 lower, u32 upper,
 465                                              u32 scope, u32 node, u32 port, u32 key)
 466 {
 467         struct publication *publ;
 468         struct name_seq *seq = nametbl_find_seq(type);
 469         int index = hash(type);
 470
 471         if ((scope < TIPC_ZONE_SCOPE) || (scope > TIPC_NODE_SCOPE) ||
 472             (lower > upper)) {
 473                 pr_debug("Failed to publish illegal {%u,%u,%u} with scope %u\n",
 474                          type, lower, upper, scope);
 475                 return NULL;
 476         }
 477
 478         if (!seq)
 479                 seq = tipc_nameseq_create(type,
 480                                           &tipc_nametbl->seq_hlist[index]);
 481         if (!seq)
 482                 return NULL;
 483
 484         spin_lock_bh(&seq->lock);
 485         publ = tipc_nameseq_insert_publ(seq, type, lower, upper,
 486                                         scope, node, port, key);
 487         spin_unlock_bh(&seq->lock);
 488         return publ;
 489 }
 490
 491 struct publication *tipc_nametbl_remove_publ(u32 type, u32 lower,
 492                                              u32 node, u32 ref, u32 key)
 493 {
 494         struct publication *publ;
 495         struct name_seq *seq = nametbl_find_seq(type);
 496
 497         if (!seq)
 498                 return NULL;
 499
 500         spin_lock_bh(&seq->lock);
 501         publ = tipc_nameseq_remove_publ(seq, lower, node, ref, key);
 502         if (!seq->first_free && list_empty(&seq->subscriptions)) {
 503                 hlist_del_init_rcu(&seq->ns_list);
 504                 kfree(seq->sseqs);
 505                 spin_unlock_bh(&seq->lock);
 506                 kfree_rcu(seq, rcu);
 507                 return publ;
 508         }
 509         spin_unlock_bh(&seq->lock);
 510         return publ;
 511 }
 512
 513 /**
 514  * tipc_nametbl_translate - perform name translation
 515  *
 516  * On entry, 'destnode' is the search domain used during translation.
 517  *
 518  * On exit:
 519  * - if name translation is deferred to another node/cluster/zone,
 520  *   leaves 'destnode' unchanged (will be non-zero) and returns 0
 521  * - if name translation is attempted and succeeds, sets 'destnode'
 522  *   to publishing node and returns port reference (will be non-zero)
 523  * - if name translation is attempted and fails, sets 'destnode' to 0
 524  *   and returns 0
 525  */
 526 u32 tipc_nametbl_translate(u32 type, u32 instance, u32 *destnode)
 527 {
 528         struct sub_seq *sseq;
 529         struct name_info *info;
 530         struct publication *publ;
 531         struct name_seq *seq;
 532         u32 ref = 0;
 533         u32 node = 0;
 534
 535         if (!tipc_in_scope(*destnode, tipc_own_addr))
 536                 return 0;
 537
 538         rcu_read_lock();
 539         seq = nametbl_find_seq(type);
 540         if (unlikely(!seq))
 541                 goto not_found;
 542         spin_lock_bh(&seq->lock);
 543         sseq = nameseq_find_subseq(seq, instance);
 544         if (unlikely(!sseq))
 545                 goto no_match;
 546         info = sseq->info;
 547
 548         /* Closest-First Algorithm */
 549         if (likely(!*destnode)) {
 550                 if (!list_empty(&info->node_list)) {
 551                         publ = list_first_entry(&info->node_list,
 552                                                 struct publication,
 553                                                 node_list);
 554                         list_move_tail(&publ->node_list,
 555                                        &info->node_list);
 556                 } else if (!list_empty(&info->cluster_list)) {
 557                         publ = list_first_entry(&info->cluster_list,
 558                                                 struct publication,
 559                                                 cluster_list);
 560                         list_move_tail(&publ->cluster_list,
 561                                        &info->cluster_list);
 562                 } else {
 563                         publ = list_first_entry(&info->zone_list,
 564                                                 struct publication,
 565                                                 zone_list);
 566                         list_move_tail(&publ->zone_list,
 567                                        &info->zone_list);
 568                 }
 569         }
 570
 571         /* Round-Robin Algorithm */
 572         else if (*destnode == tipc_own_addr) {
 573                 if (list_empty(&info->node_list))
 574                         goto no_match;
 575                 publ = list_first_entry(&info->node_list, struct publication,
 576                                         node_list);
 577                 list_move_tail(&publ->node_list, &info->node_list);
 578         } else if (in_own_cluster_exact(*destnode)) {
 579                 if (list_empty(&info->cluster_list))
 580                         goto no_match;
 581                 publ = list_first_entry(&info->cluster_list, struct publication,
 582                                         cluster_list);
 583                 list_move_tail(&publ->cluster_list, &info->cluster_list);
 584         } else {
 585                 publ = list_first_entry(&info->zone_list, struct publication,
 586                                         zone_list);
 587                 list_move_tail(&publ->zone_list, &info->zone_list);
 588         }
 589
 590         ref = publ->ref;
 591         node = publ->node;
 592 no_match:
 593         spin_unlock_bh(&seq->lock);
 594 not_found:
 595         rcu_read_unlock();
 596         *destnode = node;
 597         return ref;
 598 }
 599
 600 /**
 601  * tipc_nametbl_mc_translate - find multicast destinations
 602  *
 603  * Creates list of all local ports that overlap the given multicast address;
 604  * also determines if any off-node ports overlap.
 605  *
 606  * Note: Publications with a scope narrower than 'limit' are ignored.
 607  * (i.e. local node-scope publications mustn't receive messages arriving
 608  * from another node, even if the multcast link brought it here)
 609  *
 610  * Returns non-zero if any off-node ports overlap
 611  */
 612 int tipc_nametbl_mc_translate(u32 type, u32 lower, u32 upper, u32 limit,
 613                               struct tipc_port_list *dports)
 614 {
 615         struct name_seq *seq;
 616         struct sub_seq *sseq;
 617         struct sub_seq *sseq_stop;
 618         struct name_info *info;
 619         int res = 0;
 620
 621         rcu_read_lock();
 622         seq = nametbl_find_seq(type);
 623         if (!seq)
 624                 goto exit;
 625
 626         spin_lock_bh(&seq->lock);
 627         sseq = seq->sseqs + nameseq_locate_subseq(seq, lower);
 628         sseq_stop = seq->sseqs + seq->first_free;
 629         for (; sseq != sseq_stop; sseq++) {
 630                 struct publication *publ;
 631
 632                 if (sseq->lower > upper)
 633                         break;
 634
 635                 info = sseq->info;
 636                 list_for_each_entry(publ, &info->node_list, node_list) {
 637                         if (publ->scope <= limit)
 638                                 tipc_port_list_add(dports, publ->ref);
 639                 }
 640
 641                 if (info->cluster_list_size != info->node_list_size)
 642                         res = 1;
 643         }
 644         spin_unlock_bh(&seq->lock);
 645 exit:
 646         rcu_read_unlock();
 647         return res;
 648 }
 649
 650 /*
 651  * tipc_nametbl_publish - add name publication to network name tables
 652  */
 653 struct publication *tipc_nametbl_publish(u32 type, u32 lower, u32 upper,
 654                                          u32 scope, u32 port_ref, u32 key)
 655 {
 656         struct publication *publ;
 657         struct sk_buff *buf = NULL;
 658
 659         spin_lock_bh(&tipc_nametbl_lock);
 660         if (tipc_nametbl->local_publ_count >= TIPC_MAX_PUBLICATIONS) {
 661                 pr_warn("Publication failed, local publication limit reached (%u)\n",
 662                         TIPC_MAX_PUBLICATIONS);
 663                 spin_unlock_bh(&tipc_nametbl_lock);
 664                 return NULL;
 665         }
 666
 667         publ = tipc_nametbl_insert_publ(type, lower, upper, scope,
 668                                    tipc_own_addr, port_ref, key);
 669         if (likely(publ)) {
 670                 tipc_nametbl->local_publ_count++;
 671                 buf = tipc_named_publish(publ);
 672                 /* Any pending external events? */
 673                 tipc_named_process_backlog();
 674         }
 675         spin_unlock_bh(&tipc_nametbl_lock);
 676
 677         if (buf)
 678                 named_cluster_distribute(buf);
 679         return publ;
 680 }
 681
 682 /**
 683  * tipc_nametbl_withdraw - withdraw name publication from network name tables
 684  */
 685 int tipc_nametbl_withdraw(u32 type, u32 lower, u32 ref, u32 key)
 686 {
 687         struct publication *publ;
 688         struct sk_buff *skb = NULL;
 689
 690         spin_lock_bh(&tipc_nametbl_lock);
 691         publ = tipc_nametbl_remove_publ(type, lower, tipc_own_addr, ref, key);
 692         if (likely(publ)) {
 693                 tipc_nametbl->local_publ_count--;
 694                 skb = tipc_named_withdraw(publ);
 695                 /* Any pending external events? */
 696                 tipc_named_process_backlog();
 697                 list_del_init(&publ->pport_list);
 698                 kfree_rcu(publ, rcu);
 699         } else {
 700                 pr_err("Unable to remove local publication\n"
 701                        "(type=%u, lower=%u, ref=%u, key=%u)\n",
 702                        type, lower, ref, key);
 703         }
 704         spin_unlock_bh(&tipc_nametbl_lock);
 705
 706         if (skb) {
 707                 named_cluster_distribute(skb);
 708                 return 1;
 709         }
 710         return 0;
 711 }
 712
 713 /**
 714  * tipc_nametbl_subscribe - add a subscription object to the name table
 715  */
 716 void tipc_nametbl_subscribe(struct tipc_subscription *s)
 717 {
 718         u32 type = s->seq.type;
 719         int index = hash(type);
 720         struct name_seq *seq;
 721
 722         spin_lock_bh(&tipc_nametbl_lock);
 723         seq = nametbl_find_seq(type);
 724         if (!seq)
 725                 seq = tipc_nameseq_create(type,
 726                                           &tipc_nametbl->seq_hlist[index]);
 727         if (seq) {
 728                 spin_lock_bh(&seq->lock);
 729                 tipc_nameseq_subscribe(seq, s);
 730                 spin_unlock_bh(&seq->lock);
 731         } else {
 732                 pr_warn("Failed to create subscription for {%u,%u,%u}\n",
 733                         s->seq.type, s->seq.lower, s->seq.upper);
 734         }
 735         spin_unlock_bh(&tipc_nametbl_lock);
 736 }
 737
 738 /**
 739  * tipc_nametbl_unsubscribe - remove a subscription object from name table
 740  */
 741 void tipc_nametbl_unsubscribe(struct tipc_subscription *s)
 742 {
 743         struct name_seq *seq;
 744
 745         spin_lock_bh(&tipc_nametbl_lock);
 746         seq = nametbl_find_seq(s->seq.type);
 747         if (seq != NULL) {
 748                 spin_lock_bh(&seq->lock);
 749                 list_del_init(&s->nameseq_list);
 750                 if (!seq->first_free && list_empty(&seq->subscriptions)) {
 751                         hlist_del_init_rcu(&seq->ns_list);
 752                         kfree(seq->sseqs);
 753                         spin_unlock_bh(&seq->lock);
 754                         kfree_rcu(seq, rcu);
 755                 } else {
 756                         spin_unlock_bh(&seq->lock);
 757                 }
 758         }
 759         spin_unlock_bh(&tipc_nametbl_lock);
 760 }
 761
 762 /**
 763  * subseq_list - print specified sub-sequence contents into the given buffer
 764  */
 765 static int subseq_list(struct sub_seq *sseq, char *buf, int len, u32 depth,
 766                        u32 index)
 767 {
 768         char portIdStr[27];
 769         const char *scope_str[] = {"", " zone", " cluster", " node"};
 770         struct publication *publ;
 771         struct name_info *info;
 772         int ret;
 773
 774         ret = tipc_snprintf(buf, len, "%-10u %-10u ", sseq->lower, sseq->upper);
 775
 776         if (depth == 2) {
 777                 ret += tipc_snprintf(buf - ret, len + ret, "\n");
 778                 return ret;
 779         }
 780
 781         info = sseq->info;
 782
 783         list_for_each_entry(publ, &info->zone_list, zone_list) {
 784                 sprintf(portIdStr, "<%u.%u.%u:%u>",
 785                          tipc_zone(publ->node), tipc_cluster(publ->node),
 786                          tipc_node(publ->node), publ->ref);
 787                 ret += tipc_snprintf(buf + ret, len - ret, "%-26s ", portIdStr);
 788                 if (depth > 3) {
 789                         ret += tipc_snprintf(buf + ret, len - ret, "%-10u %s",
 790                                              publ->key, scope_str[publ->scope]);
 791                 }
 792                 if (!list_is_last(&publ->zone_list, &info->zone_list))
 793                         ret += tipc_snprintf(buf + ret, len - ret,
 794                                              "\n%33s", " ");
 795         }
 796
 797         ret += tipc_snprintf(buf + ret, len - ret, "\n");
 798         return ret;
 799 }
 800
 801 /**
 802  * nameseq_list - print specified name sequence contents into the given buffer
 803  */
 804 static int nameseq_list(struct name_seq *seq, char *buf, int len, u32 depth,
 805                         u32 type, u32 lowbound, u32 upbound, u32 index)
 806 {
 807         struct sub_seq *sseq;
 808         char typearea[11];
 809         int ret = 0;
 810
 811         if (seq->first_free == 0)
 812                 return 0;
 813
 814         sprintf(typearea, "%-10u", seq->type);
 815
 816         if (depth == 1) {
 817                 ret += tipc_snprintf(buf, len, "%s\n", typearea);
 818                 return ret;
 819         }
 820
 821         for (sseq = seq->sseqs; sseq != &seq->sseqs[seq->first_free]; sseq++) {
 822                 if ((lowbound <= sseq->upper) && (upbound >= sseq->lower)) {
 823                         ret += tipc_snprintf(buf + ret, len - ret, "%s ",
 824                                             typearea);
 825                         spin_lock_bh(&seq->lock);
 826                         ret += subseq_list(sseq, buf + ret, len - ret,
 827                                           depth, index);
 828                         spin_unlock_bh(&seq->lock);
 829                         sprintf(typearea, "%10s", " ");
 830                 }
 831         }
 832         return ret;
 833 }
 834
 835 /**
 836  * nametbl_header - print name table header into the given buffer
 837  */
 838 static int nametbl_header(char *buf, int len, u32 depth)
 839 {
 840         const char *header[] = {
 841                 "Type       ",
 842                 "Lower      Upper      ",
 843                 "Port Identity              ",
 844                 "Publication Scope"
 845         };
 846
 847         int i;
 848         int ret = 0;
 849
 850         if (depth > 4)
 851                 depth = 4;
 852         for (i = 0; i < depth; i++)
 853                 ret += tipc_snprintf(buf + ret, len - ret, header[i]);
 854         ret += tipc_snprintf(buf + ret, len - ret, "\n");
 855         return ret;
 856 }
 857
 858 /**
 859  * nametbl_list - print specified name table contents into the given buffer
 860  */
 861 static int nametbl_list(char *buf, int len, u32 depth_info,
 862                         u32 type, u32 lowbound, u32 upbound)
 863 {
 864         struct hlist_head *seq_head;
 865         struct name_seq *seq;
 866         int all_types;
 867         int ret = 0;
 868         u32 depth;
 869         u32 i;
 870
 871         all_types = (depth_info & TIPC_NTQ_ALLTYPES);
 872         depth = (depth_info & ~TIPC_NTQ_ALLTYPES);
 873
 874         if (depth == 0)
 875                 return 0;
 876
 877         if (all_types) {
 878                 /* display all entries in name table to specified depth */
 879                 ret += nametbl_header(buf, len, depth);
 880                 lowbound = 0;
 881                 upbound = ~0;
 882                 for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
 883                         seq_head = &tipc_nametbl->seq_hlist[i];
 884                         hlist_for_each_entry_rcu(seq, seq_head, ns_list) {
 885                                 ret += nameseq_list(seq, buf + ret, len - ret,
 886                                                    depth, seq->type,
 887                                                    lowbound, upbound, i);
 888                         }
 889                 }
 890         } else {
 891                 /* display only the sequence that matches the specified type */
 892                 if (upbound < lowbound) {
 893                         ret += tipc_snprintf(buf + ret, len - ret,
 894                                         "invalid name sequence specified\n");
 895                         return ret;
 896                 }
 897                 ret += nametbl_header(buf + ret, len - ret, depth);
 898                 i = hash(type);
 899                 seq_head = &tipc_nametbl->seq_hlist[i];
 900                 hlist_for_each_entry_rcu(seq, seq_head, ns_list) {
 901                         if (seq->type == type) {
 902                                 ret += nameseq_list(seq, buf + ret, len - ret,
 903                                                    depth, type,
 904                                                    lowbound, upbound, i);
 905                                 break;
 906                         }
 907                 }
 908         }
 909         return ret;
 910 }
 911
 912 struct sk_buff *tipc_nametbl_get(const void *req_tlv_area, int req_tlv_space)
 913 {
 914         struct sk_buff *buf;
 915         struct tipc_name_table_query *argv;
 916         struct tlv_desc *rep_tlv;
 917         char *pb;
 918         int pb_len;
 919         int str_len;
 920
 921         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NAME_TBL_QUERY))
 922                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 923
 924         buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
 925         if (!buf)
 926                 return NULL;
 927
 928         rep_tlv = (struct tlv_desc *)buf->data;
 929         pb = TLV_DATA(rep_tlv);
 930         pb_len = ULTRA_STRING_MAX_LEN;
 931         argv = (struct tipc_name_table_query *)TLV_DATA(req_tlv_area);
 932         rcu_read_lock();
 933         str_len = nametbl_list(pb, pb_len, ntohl(argv->depth),
 934                                ntohl(argv->type),
 935                                ntohl(argv->lowbound), ntohl(argv->upbound));
 936         rcu_read_unlock();
 937         str_len += 1;   /* for "\0" */
 938         skb_put(buf, TLV_SPACE(str_len));
 939         TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
 940
 941         return buf;
 942 }
 943
 944 int tipc_nametbl_init(void)
 945 {
 946         int i;
 947
 948         tipc_nametbl = kzalloc(sizeof(*tipc_nametbl), GFP_ATOMIC);
 949         if (!tipc_nametbl)
 950                 return -ENOMEM;
 951
 952         for (i = 0; i < TIPC_NAMETBL_SIZE; i++)
 953                 INIT_HLIST_HEAD(&tipc_nametbl->seq_hlist[i]);
 954
 955         INIT_LIST_HEAD(&tipc_nametbl->publ_list[TIPC_ZONE_SCOPE]);
 956         INIT_LIST_HEAD(&tipc_nametbl->publ_list[TIPC_CLUSTER_SCOPE]);
 957         INIT_LIST_HEAD(&tipc_nametbl->publ_list[TIPC_NODE_SCOPE]);
 958         return 0;
 959 }
 960
 961 /**
 962  * tipc_purge_publications - remove all publications for a given type
 963  *
 964  * tipc_nametbl_lock must be held when calling this function
 965  */
 966 static void tipc_purge_publications(struct name_seq *seq)
 967 {
 968         struct publication *publ, *safe;
 969         struct sub_seq *sseq;
 970         struct name_info *info;
 971
 972         spin_lock_bh(&seq->lock);
 973         sseq = seq->sseqs;
 974         info = sseq->info;
 975         list_for_each_entry_safe(publ, safe, &info->zone_list, zone_list) {
 976                 tipc_nametbl_remove_publ(publ->type, publ->lower, publ->node,
 977                                          publ->ref, publ->key);
 978                 kfree_rcu(publ, rcu);
 979         }
 980         hlist_del_init_rcu(&seq->ns_list);
 981         kfree(seq->sseqs);
 982         spin_unlock_bh(&seq->lock);
 983
 984         kfree_rcu(seq, rcu);
 985 }
 986
 987 void tipc_nametbl_stop(void)
 988 {
 989         u32 i;
 990         struct name_seq *seq;
 991         struct hlist_head *seq_head;
 992
 993         /* Verify name table is empty and purge any lingering
 994          * publications, then release the name table
 995          */
 996         spin_lock_bh(&tipc_nametbl_lock);
 997         for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
 998                 if (hlist_empty(&tipc_nametbl->seq_hlist[i]))
 999                         continue;
1000                 seq_head = &tipc_nametbl->seq_hlist[i];
1001                 hlist_for_each_entry_rcu(seq, seq_head, ns_list) {
1002                         tipc_purge_publications(seq);
1003                 }
1004         }
1005         spin_unlock_bh(&tipc_nametbl_lock);
1006
1007         synchronize_net();
1008         kfree(tipc_nametbl);
1009
1010 }
1011
1012 static int __tipc_nl_add_nametable_publ(struct tipc_nl_msg *msg,
1013                                         struct name_seq *seq,
1014                                         struct sub_seq *sseq, u32 *last_publ)
1015 {
1016         void *hdr;
1017         struct nlattr *attrs;
1018         struct nlattr *publ;
1019         struct publication *p;
1020
1021         if (*last_publ) {
1022                 list_for_each_entry(p, &sseq->info->zone_list, zone_list)
1023                         if (p->key == *last_publ)
1024                                 break;
1025                 if (p->key != *last_publ)
1026                         return -EPIPE;
1027         } else {
1028                 p = list_first_entry(&sseq->info->zone_list, struct publication,
1029                                      zone_list);
1030         }
1031
1032         list_for_each_entry_from(p, &sseq->info->zone_list, zone_list) {
1033                 *last_publ = p->key;
1034
1035                 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq,
1036                                   &tipc_genl_v2_family, NLM_F_MULTI,
1037                                   TIPC_NL_NAME_TABLE_GET);
1038                 if (!hdr)
1039                         return -EMSGSIZE;
1040
1041                 attrs = nla_nest_start(msg->skb, TIPC_NLA_NAME_TABLE);
1042                 if (!attrs)
1043                         goto msg_full;
1044
1045                 publ = nla_nest_start(msg->skb, TIPC_NLA_NAME_TABLE_PUBL);
1046                 if (!publ)
1047                         goto attr_msg_full;
1048
1049                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_TYPE, seq->type))
1050                         goto publ_msg_full;
1051                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_LOWER, sseq->lower))
1052                         goto publ_msg_full;
1053                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_UPPER, sseq->upper))
1054                         goto publ_msg_full;
1055                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_SCOPE, p->scope))
1056                         goto publ_msg_full;
1057                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_NODE, p->node))
1058                         goto publ_msg_full;
1059                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_REF, p->ref))
1060                         goto publ_msg_full;
1061                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_KEY, p->key))
1062                         goto publ_msg_full;
1063
1064                 nla_nest_end(msg->skb, publ);
1065                 nla_nest_end(msg->skb, attrs);
1066                 genlmsg_end(msg->skb, hdr);
1067         }
1068         *last_publ = 0;
1069
1070         return 0;
1071
1072 publ_msg_full:
1073         nla_nest_cancel(msg->skb, publ);
1074 attr_msg_full:
1075         nla_nest_cancel(msg->skb, attrs);
1076 msg_full:
1077         genlmsg_cancel(msg->skb, hdr);
1078
1079         return -EMSGSIZE;
1080 }
1081
1082 static int __tipc_nl_subseq_list(struct tipc_nl_msg *msg, struct name_seq *seq,
1083                                  u32 *last_lower, u32 *last_publ)
1084 {
1085         struct sub_seq *sseq;
1086         struct sub_seq *sseq_start;
1087         int err;
1088
1089         if (*last_lower) {
1090                 sseq_start = nameseq_find_subseq(seq, *last_lower);
1091                 if (!sseq_start)
1092                         return -EPIPE;
1093         } else {
1094                 sseq_start = seq->sseqs;
1095         }
1096
1097         for (sseq = sseq_start; sseq != &seq->sseqs[seq->first_free]; sseq++) {
1098                 err = __tipc_nl_add_nametable_publ(msg, seq, sseq, last_publ);
1099                 if (err) {
1100                         *last_lower = sseq->lower;
1101                         return err;
1102                 }
1103         }
1104         *last_lower = 0;
1105
1106         return 0;
1107 }
1108
1109 static int __tipc_nl_seq_list(struct tipc_nl_msg *msg, u32 *last_type,
1110                               u32 *last_lower, u32 *last_publ)
1111 {
1112         struct hlist_head *seq_head;
1113         struct name_seq *seq = NULL;
1114         int err;
1115         int i;
1116
1117         if (*last_type)
1118                 i = hash(*last_type);
1119         else
1120                 i = 0;
1121
1122         for (; i < TIPC_NAMETBL_SIZE; i++) {
1123                 seq_head = &tipc_nametbl->seq_hlist[i];
1124
1125                 if (*last_type) {
1126                         seq = nametbl_find_seq(*last_type);
1127                         if (!seq)
1128                                 return -EPIPE;
1129                 } else {
1130                         hlist_for_each_entry_rcu(seq, seq_head, ns_list)
1131                                 break;
1132                         if (!seq)
1133                                 continue;
1134                 }
1135
1136                 hlist_for_each_entry_from_rcu(seq, ns_list) {
1137                         spin_lock_bh(&seq->lock);
1138                         err = __tipc_nl_subseq_list(msg, seq, last_lower,
1139                                                     last_publ);
1140
1141                         if (err) {
1142                                 *last_type = seq->type;
1143                                 spin_unlock_bh(&seq->lock);
1144                                 return err;
1145                         }
1146                         spin_unlock_bh(&seq->lock);
1147                 }
1148                 *last_type = 0;
1149         }
1150         return 0;
1151 }
1152
1153 int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
1154 {
1155         int err;
1156         int done = cb->args[3];
1157         u32 last_type = cb->args[0];
1158         u32 last_lower = cb->args[1];
1159         u32 last_publ = cb->args[2];
1160         struct tipc_nl_msg msg;
1161
1162         if (done)
1163                 return 0;
1164
1165         msg.skb = skb;
1166         msg.portid = NETLINK_CB(cb->skb).portid;
1167         msg.seq = cb->nlh->nlmsg_seq;
1168
1169         rcu_read_lock();
1170         err = __tipc_nl_seq_list(&msg, &last_type, &last_lower, &last_publ);
1171         if (!err) {
1172                 done = 1;
1173         } else if (err != -EMSGSIZE) {
1174                 /* We never set seq or call nl_dump_check_consistent() this
1175                  * means that setting prev_seq here will cause the consistence
1176                  * check to fail in the netlink callback handler. Resulting in
1177                  * the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if
1178                  * we got an error.
1179                  */
1180                 cb->prev_seq = 1;
1181         }
1182         rcu_read_unlock();
1183
1184         cb->args[0] = last_type;
1185         cb->args[1] = last_lower;
1186         cb->args[2] = last_publ;
1187         cb->args[3] = done;
1188
1189         return skb->len;
1190 }