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  */
  96 struct name_seq {
  97         u32 type;
  98         struct sub_seq *sseqs;
  99         u32 alloc;
 100         u32 first_free;
 101         struct hlist_node ns_list;
 102         struct list_head subscriptions;
 103         spinlock_t lock;
 104 };
 105
 106 struct name_table *tipc_nametbl;
 107 DEFINE_RWLOCK(tipc_nametbl_lock);
 108
 109 static int hash(int x)
 110 {
 111         return x & (TIPC_NAMETBL_SIZE - 1);
 112 }
 113
 114 /**
 115  * publ_create - create a publication structure
 116  */
 117 static struct publication *publ_create(u32 type, u32 lower, u32 upper,
 118                                        u32 scope, u32 node, u32 port_ref,
 119                                        u32 key)
 120 {
 121         struct publication *publ = kzalloc(sizeof(*publ), GFP_ATOMIC);
 122         if (publ == NULL) {
 123                 pr_warn("Publication creation failure, no memory\n");
 124                 return NULL;
 125         }
 126
 127         publ->type = type;
 128         publ->lower = lower;
 129         publ->upper = upper;
 130         publ->scope = scope;
 131         publ->node = node;
 132         publ->ref = port_ref;
 133         publ->key = key;
 134         INIT_LIST_HEAD(&publ->local_list);
 135         INIT_LIST_HEAD(&publ->pport_list);
 136         INIT_LIST_HEAD(&publ->nodesub_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(&nseq->ns_list, seq_head);
 172         return nseq;
 173 }
 174
 175 /*
 176  * nameseq_delete_empty - deletes a name sequence structure if now unused
 177  */
 178 static void nameseq_delete_empty(struct name_seq *seq)
 179 {
 180         if (!seq->first_free && list_empty(&seq->subscriptions)) {
 181                 hlist_del_init(&seq->ns_list);
 182                 kfree(seq->sseqs);
 183                 kfree(seq);
 184         }
 185 }
 186
 187 /**
 188  * nameseq_find_subseq - find sub-sequence (if any) matching a name instance
 189  *
 190  * Very time-critical, so binary searches through sub-sequence array.
 191  */
 192 static struct sub_seq *nameseq_find_subseq(struct name_seq *nseq,
 193                                            u32 instance)
 194 {
 195         struct sub_seq *sseqs = nseq->sseqs;
 196         int low = 0;
 197         int high = nseq->first_free - 1;
 198         int mid;
 199
 200         while (low <= high) {
 201                 mid = (low + high) / 2;
 202                 if (instance < sseqs[mid].lower)
 203                         high = mid - 1;
 204                 else if (instance > sseqs[mid].upper)
 205                         low = mid + 1;
 206                 else
 207                         return &sseqs[mid];
 208         }
 209         return NULL;
 210 }
 211
 212 /**
 213  * nameseq_locate_subseq - determine position of name instance in sub-sequence
 214  *
 215  * Returns index in sub-sequence array of the entry that contains the specified
 216  * instance value; if no entry contains that value, returns the position
 217  * where a new entry for it would be inserted in the array.
 218  *
 219  * Note: Similar to binary search code for locating a sub-sequence.
 220  */
 221 static u32 nameseq_locate_subseq(struct name_seq *nseq, u32 instance)
 222 {
 223         struct sub_seq *sseqs = nseq->sseqs;
 224         int low = 0;
 225         int high = nseq->first_free - 1;
 226         int mid;
 227
 228         while (low <= high) {
 229                 mid = (low + high) / 2;
 230                 if (instance < sseqs[mid].lower)
 231                         high = mid - 1;
 232                 else if (instance > sseqs[mid].upper)
 233                         low = mid + 1;
 234                 else
 235                         return mid;
 236         }
 237         return low;
 238 }
 239
 240 /**
 241  * tipc_nameseq_insert_publ
 242  */
 243 static struct publication *tipc_nameseq_insert_publ(struct name_seq *nseq,
 244                                                     u32 type, u32 lower, u32 upper,
 245                                                     u32 scope, u32 node, u32 port, u32 key)
 246 {
 247         struct tipc_subscription *s;
 248         struct tipc_subscription *st;
 249         struct publication *publ;
 250         struct sub_seq *sseq;
 251         struct name_info *info;
 252         int created_subseq = 0;
 253
 254         sseq = nameseq_find_subseq(nseq, lower);
 255         if (sseq) {
 256
 257                 /* Lower end overlaps existing entry => need an exact match */
 258                 if ((sseq->lower != lower) || (sseq->upper != upper)) {
 259                         return NULL;
 260                 }
 261
 262                 info = sseq->info;
 263
 264                 /* Check if an identical publication already exists */
 265                 list_for_each_entry(publ, &info->zone_list, zone_list) {
 266                         if ((publ->ref == port) && (publ->key == key) &&
 267                             (!publ->node || (publ->node == node)))
 268                                 return NULL;
 269                 }
 270         } else {
 271                 u32 inspos;
 272                 struct sub_seq *freesseq;
 273
 274                 /* Find where lower end should be inserted */
 275                 inspos = nameseq_locate_subseq(nseq, lower);
 276
 277                 /* Fail if upper end overlaps into an existing entry */
 278                 if ((inspos < nseq->first_free) &&
 279                     (upper >= nseq->sseqs[inspos].lower)) {
 280                         return NULL;
 281                 }
 282
 283                 /* Ensure there is space for new sub-sequence */
 284                 if (nseq->first_free == nseq->alloc) {
 285                         struct sub_seq *sseqs = tipc_subseq_alloc(nseq->alloc * 2);
 286
 287                         if (!sseqs) {
 288                                 pr_warn("Cannot publish {%u,%u,%u}, no memory\n",
 289                                         type, lower, upper);
 290                                 return NULL;
 291                         }
 292                         memcpy(sseqs, nseq->sseqs,
 293                                nseq->alloc * sizeof(struct sub_seq));
 294                         kfree(nseq->sseqs);
 295                         nseq->sseqs = sseqs;
 296                         nseq->alloc *= 2;
 297                 }
 298
 299                 info = kzalloc(sizeof(*info), GFP_ATOMIC);
 300                 if (!info) {
 301                         pr_warn("Cannot publish {%u,%u,%u}, no memory\n",
 302                                 type, lower, upper);
 303                         return NULL;
 304                 }
 305
 306                 INIT_LIST_HEAD(&info->node_list);
 307                 INIT_LIST_HEAD(&info->cluster_list);
 308                 INIT_LIST_HEAD(&info->zone_list);
 309
 310                 /* Insert new sub-sequence */
 311                 sseq = &nseq->sseqs[inspos];
 312                 freesseq = &nseq->sseqs[nseq->first_free];
 313                 memmove(sseq + 1, sseq, (freesseq - sseq) * sizeof(*sseq));
 314                 memset(sseq, 0, sizeof(*sseq));
 315                 nseq->first_free++;
 316                 sseq->lower = lower;
 317                 sseq->upper = upper;
 318                 sseq->info = info;
 319                 created_subseq = 1;
 320         }
 321
 322         /* Insert a publication */
 323         publ = publ_create(type, lower, upper, scope, node, port, key);
 324         if (!publ)
 325                 return NULL;
 326
 327         list_add(&publ->zone_list, &info->zone_list);
 328         info->zone_list_size++;
 329
 330         if (in_own_cluster(node)) {
 331                 list_add(&publ->cluster_list, &info->cluster_list);
 332                 info->cluster_list_size++;
 333         }
 334
 335         if (in_own_node(node)) {
 336                 list_add(&publ->node_list, &info->node_list);
 337                 info->node_list_size++;
 338         }
 339
 340         /* Any subscriptions waiting for notification?  */
 341         list_for_each_entry_safe(s, st, &nseq->subscriptions, nameseq_list) {
 342                 tipc_subscr_report_overlap(s,
 343                                            publ->lower,
 344                                            publ->upper,
 345                                            TIPC_PUBLISHED,
 346                                            publ->ref,
 347                                            publ->node,
 348                                            created_subseq);
 349         }
 350         return publ;
 351 }
 352
 353 /**
 354  * tipc_nameseq_remove_publ
 355  *
 356  * NOTE: There may be cases where TIPC is asked to remove a publication
 357  * that is not in the name table.  For example, if another node issues a
 358  * publication for a name sequence that overlaps an existing name sequence
 359  * the publication will not be recorded, which means the publication won't
 360  * be found when the name sequence is later withdrawn by that node.
 361  * A failed withdraw request simply returns a failure indication and lets the
 362  * caller issue any error or warning messages associated with such a problem.
 363  */
 364 static struct publication *tipc_nameseq_remove_publ(struct name_seq *nseq, u32 inst,
 365                                                     u32 node, u32 ref, u32 key)
 366 {
 367         struct publication *publ;
 368         struct sub_seq *sseq = nameseq_find_subseq(nseq, inst);
 369         struct name_info *info;
 370         struct sub_seq *free;
 371         struct tipc_subscription *s, *st;
 372         int removed_subseq = 0;
 373
 374         if (!sseq)
 375                 return NULL;
 376
 377         info = sseq->info;
 378
 379         /* Locate publication, if it exists */
 380         list_for_each_entry(publ, &info->zone_list, zone_list) {
 381                 if ((publ->key == key) && (publ->ref == ref) &&
 382                     (!publ->node || (publ->node == node)))
 383                         goto found;
 384         }
 385         return NULL;
 386
 387 found:
 388         /* Remove publication from zone scope list */
 389         list_del(&publ->zone_list);
 390         info->zone_list_size--;
 391
 392         /* Remove publication from cluster scope list, if present */
 393         if (in_own_cluster(node)) {
 394                 list_del(&publ->cluster_list);
 395                 info->cluster_list_size--;
 396         }
 397
 398         /* Remove publication from node scope list, if present */
 399         if (in_own_node(node)) {
 400                 list_del(&publ->node_list);
 401                 info->node_list_size--;
 402         }
 403
 404         /* Contract subseq list if no more publications for that subseq */
 405         if (list_empty(&info->zone_list)) {
 406                 kfree(info);
 407                 free = &nseq->sseqs[nseq->first_free--];
 408                 memmove(sseq, sseq + 1, (free - (sseq + 1)) * sizeof(*sseq));
 409                 removed_subseq = 1;
 410         }
 411
 412         /* Notify any waiting subscriptions */
 413         list_for_each_entry_safe(s, st, &nseq->subscriptions, nameseq_list) {
 414                 tipc_subscr_report_overlap(s,
 415                                            publ->lower,
 416                                            publ->upper,
 417                                            TIPC_WITHDRAWN,
 418                                            publ->ref,
 419                                            publ->node,
 420                                            removed_subseq);
 421         }
 422
 423         return publ;
 424 }
 425
 426 /**
 427  * tipc_nameseq_subscribe - attach a subscription, and issue
 428  * the prescribed number of events if there is any sub-
 429  * sequence overlapping with the requested sequence
 430  */
 431 static void tipc_nameseq_subscribe(struct name_seq *nseq,
 432                                    struct tipc_subscription *s)
 433 {
 434         struct sub_seq *sseq = nseq->sseqs;
 435
 436         list_add(&s->nameseq_list, &nseq->subscriptions);
 437
 438         if (!sseq)
 439                 return;
 440
 441         while (sseq != &nseq->sseqs[nseq->first_free]) {
 442                 if (tipc_subscr_overlap(s, sseq->lower, sseq->upper)) {
 443                         struct publication *crs;
 444                         struct name_info *info = sseq->info;
 445                         int must_report = 1;
 446
 447                         list_for_each_entry(crs, &info->zone_list, zone_list) {
 448                                 tipc_subscr_report_overlap(s,
 449                                                            sseq->lower,
 450                                                            sseq->upper,
 451                                                            TIPC_PUBLISHED,
 452                                                            crs->ref,
 453                                                            crs->node,
 454                                                            must_report);
 455                                 must_report = 0;
 456                         }
 457                 }
 458                 sseq++;
 459         }
 460 }
 461
 462 static struct name_seq *nametbl_find_seq(u32 type)
 463 {
 464         struct hlist_head *seq_head;
 465         struct name_seq *ns;
 466
 467         seq_head = &tipc_nametbl->seq_hlist[hash(type)];
 468         hlist_for_each_entry(ns, seq_head, ns_list) {
 469                 if (ns->type == type)
 470                         return ns;
 471         }
 472
 473         return NULL;
 474 };
 475
 476 struct publication *tipc_nametbl_insert_publ(u32 type, u32 lower, u32 upper,
 477                                              u32 scope, u32 node, u32 port, u32 key)
 478 {
 479         struct name_seq *seq = nametbl_find_seq(type);
 480         int index = hash(type);
 481
 482         if ((scope < TIPC_ZONE_SCOPE) || (scope > TIPC_NODE_SCOPE) ||
 483             (lower > upper)) {
 484                 pr_debug("Failed to publish illegal {%u,%u,%u} with scope %u\n",
 485                          type, lower, upper, scope);
 486                 return NULL;
 487         }
 488
 489         if (!seq)
 490                 seq = tipc_nameseq_create(type,
 491                                           &tipc_nametbl->seq_hlist[index]);
 492         if (!seq)
 493                 return NULL;
 494
 495         return tipc_nameseq_insert_publ(seq, type, lower, upper,
 496                                         scope, node, port, key);
 497 }
 498
 499 struct publication *tipc_nametbl_remove_publ(u32 type, u32 lower,
 500                                              u32 node, u32 ref, u32 key)
 501 {
 502         struct publication *publ;
 503         struct name_seq *seq = nametbl_find_seq(type);
 504
 505         if (!seq)
 506                 return NULL;
 507
 508         publ = tipc_nameseq_remove_publ(seq, lower, node, ref, key);
 509         nameseq_delete_empty(seq);
 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         read_lock_bh(&tipc_nametbl_lock);
 539         seq = nametbl_find_seq(type);
 540         if (unlikely(!seq))
 541                 goto not_found;
 542         sseq = nameseq_find_subseq(seq, instance);
 543         if (unlikely(!sseq))
 544                 goto not_found;
 545         spin_lock_bh(&seq->lock);
 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         read_unlock_bh(&tipc_nametbl_lock);
 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         read_lock_bh(&tipc_nametbl_lock);
 622         seq = nametbl_find_seq(type);
 623         if (!seq)
 624                 goto exit;
 625
 626         spin_lock_bh(&seq->lock);
 627
 628         sseq = seq->sseqs + nameseq_locate_subseq(seq, lower);
 629         sseq_stop = seq->sseqs + seq->first_free;
 630         for (; sseq != sseq_stop; sseq++) {
 631                 struct publication *publ;
 632
 633                 if (sseq->lower > upper)
 634                         break;
 635
 636                 info = sseq->info;
 637                 list_for_each_entry(publ, &info->node_list, node_list) {
 638                         if (publ->scope <= limit)
 639                                 tipc_port_list_add(dports, publ->ref);
 640                 }
 641
 642                 if (info->cluster_list_size != info->node_list_size)
 643                         res = 1;
 644         }
 645
 646         spin_unlock_bh(&seq->lock);
 647 exit:
 648         read_unlock_bh(&tipc_nametbl_lock);
 649         return res;
 650 }
 651
 652 /*
 653  * tipc_nametbl_publish - add name publication to network name tables
 654  */
 655 struct publication *tipc_nametbl_publish(u32 type, u32 lower, u32 upper,
 656                                          u32 scope, u32 port_ref, u32 key)
 657 {
 658         struct publication *publ;
 659         struct sk_buff *buf = NULL;
 660
 661         if (tipc_nametbl->local_publ_count >= TIPC_MAX_PUBLICATIONS) {
 662                 pr_warn("Publication failed, local publication limit reached (%u)\n",
 663                         TIPC_MAX_PUBLICATIONS);
 664                 return NULL;
 665         }
 666
 667         write_lock_bh(&tipc_nametbl_lock);
 668         publ = tipc_nametbl_insert_publ(type, lower, upper, scope,
 669                                    tipc_own_addr, port_ref, key);
 670         if (likely(publ)) {
 671                 tipc_nametbl->local_publ_count++;
 672                 buf = tipc_named_publish(publ);
 673                 /* Any pending external events? */
 674                 tipc_named_process_backlog();
 675         }
 676         write_unlock_bh(&tipc_nametbl_lock);
 677
 678         if (buf)
 679                 named_cluster_distribute(buf);
 680         return publ;
 681 }
 682
 683 /**
 684  * tipc_nametbl_withdraw - withdraw name publication from network name tables
 685  */
 686 int tipc_nametbl_withdraw(u32 type, u32 lower, u32 ref, u32 key)
 687 {
 688         struct publication *publ;
 689         struct sk_buff *buf;
 690
 691         write_lock_bh(&tipc_nametbl_lock);
 692         publ = tipc_nametbl_remove_publ(type, lower, tipc_own_addr, ref, key);
 693         if (likely(publ)) {
 694                 tipc_nametbl->local_publ_count--;
 695                 buf = tipc_named_withdraw(publ);
 696                 /* Any pending external events? */
 697                 tipc_named_process_backlog();
 698                 write_unlock_bh(&tipc_nametbl_lock);
 699                 list_del_init(&publ->pport_list);
 700                 kfree(publ);
 701
 702                 if (buf)
 703                         named_cluster_distribute(buf);
 704                 return 1;
 705         }
 706         write_unlock_bh(&tipc_nametbl_lock);
 707         pr_err("Unable to remove local publication\n"
 708                "(type=%u, lower=%u, ref=%u, key=%u)\n",
 709                type, lower, ref, key);
 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         write_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         write_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         write_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                 spin_unlock_bh(&seq->lock);
 751                 nameseq_delete_empty(seq);
 752         }
 753         write_unlock_bh(&tipc_nametbl_lock);
 754 }
 755
 756
 757 /**
 758  * subseq_list - print specified sub-sequence contents into the given buffer
 759  */
 760 static int subseq_list(struct sub_seq *sseq, char *buf, int len, u32 depth,
 761                        u32 index)
 762 {
 763         char portIdStr[27];
 764         const char *scope_str[] = {"", " zone", " cluster", " node"};
 765         struct publication *publ;
 766         struct name_info *info;
 767         int ret;
 768
 769         ret = tipc_snprintf(buf, len, "%-10u %-10u ", sseq->lower, sseq->upper);
 770
 771         if (depth == 2) {
 772                 ret += tipc_snprintf(buf - ret, len + ret, "\n");
 773                 return ret;
 774         }
 775
 776         info = sseq->info;
 777
 778         list_for_each_entry(publ, &info->zone_list, zone_list) {
 779                 sprintf(portIdStr, "<%u.%u.%u:%u>",
 780                          tipc_zone(publ->node), tipc_cluster(publ->node),
 781                          tipc_node(publ->node), publ->ref);
 782                 ret += tipc_snprintf(buf + ret, len - ret, "%-26s ", portIdStr);
 783                 if (depth > 3) {
 784                         ret += tipc_snprintf(buf + ret, len - ret, "%-10u %s",
 785                                              publ->key, scope_str[publ->scope]);
 786                 }
 787                 if (!list_is_last(&publ->zone_list, &info->zone_list))
 788                         ret += tipc_snprintf(buf + ret, len - ret,
 789                                              "\n%33s", " ");
 790         }
 791
 792         ret += tipc_snprintf(buf + ret, len - ret, "\n");
 793         return ret;
 794 }
 795
 796 /**
 797  * nameseq_list - print specified name sequence contents into the given buffer
 798  */
 799 static int nameseq_list(struct name_seq *seq, char *buf, int len, u32 depth,
 800                         u32 type, u32 lowbound, u32 upbound, u32 index)
 801 {
 802         struct sub_seq *sseq;
 803         char typearea[11];
 804         int ret = 0;
 805
 806         if (seq->first_free == 0)
 807                 return 0;
 808
 809         sprintf(typearea, "%-10u", seq->type);
 810
 811         if (depth == 1) {
 812                 ret += tipc_snprintf(buf, len, "%s\n", typearea);
 813                 return ret;
 814         }
 815
 816         for (sseq = seq->sseqs; sseq != &seq->sseqs[seq->first_free]; sseq++) {
 817                 if ((lowbound <= sseq->upper) && (upbound >= sseq->lower)) {
 818                         ret += tipc_snprintf(buf + ret, len - ret, "%s ",
 819                                             typearea);
 820                         spin_lock_bh(&seq->lock);
 821                         ret += subseq_list(sseq, buf + ret, len - ret,
 822                                           depth, index);
 823                         spin_unlock_bh(&seq->lock);
 824                         sprintf(typearea, "%10s", " ");
 825                 }
 826         }
 827         return ret;
 828 }
 829
 830 /**
 831  * nametbl_header - print name table header into the given buffer
 832  */
 833 static int nametbl_header(char *buf, int len, u32 depth)
 834 {
 835         const char *header[] = {
 836                 "Type       ",
 837                 "Lower      Upper      ",
 838                 "Port Identity              ",
 839                 "Publication Scope"
 840         };
 841
 842         int i;
 843         int ret = 0;
 844
 845         if (depth > 4)
 846                 depth = 4;
 847         for (i = 0; i < depth; i++)
 848                 ret += tipc_snprintf(buf + ret, len - ret, header[i]);
 849         ret += tipc_snprintf(buf + ret, len - ret, "\n");
 850         return ret;
 851 }
 852
 853 /**
 854  * nametbl_list - print specified name table contents into the given buffer
 855  */
 856 static int nametbl_list(char *buf, int len, u32 depth_info,
 857                         u32 type, u32 lowbound, u32 upbound)
 858 {
 859         struct hlist_head *seq_head;
 860         struct name_seq *seq;
 861         int all_types;
 862         int ret = 0;
 863         u32 depth;
 864         u32 i;
 865
 866         all_types = (depth_info & TIPC_NTQ_ALLTYPES);
 867         depth = (depth_info & ~TIPC_NTQ_ALLTYPES);
 868
 869         if (depth == 0)
 870                 return 0;
 871
 872         if (all_types) {
 873                 /* display all entries in name table to specified depth */
 874                 ret += nametbl_header(buf, len, depth);
 875                 lowbound = 0;
 876                 upbound = ~0;
 877                 for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
 878                         seq_head = &tipc_nametbl->seq_hlist[i];
 879                         hlist_for_each_entry(seq, seq_head, ns_list) {
 880                                 ret += nameseq_list(seq, buf + ret, len - ret,
 881                                                    depth, seq->type,
 882                                                    lowbound, upbound, i);
 883                         }
 884                 }
 885         } else {
 886                 /* display only the sequence that matches the specified type */
 887                 if (upbound < lowbound) {
 888                         ret += tipc_snprintf(buf + ret, len - ret,
 889                                         "invalid name sequence specified\n");
 890                         return ret;
 891                 }
 892                 ret += nametbl_header(buf + ret, len - ret, depth);
 893                 i = hash(type);
 894                 seq_head = &tipc_nametbl->seq_hlist[i];
 895                 hlist_for_each_entry(seq, seq_head, ns_list) {
 896                         if (seq->type == type) {
 897                                 ret += nameseq_list(seq, buf + ret, len - ret,
 898                                                    depth, type,
 899                                                    lowbound, upbound, i);
 900                                 break;
 901                         }
 902                 }
 903         }
 904         return ret;
 905 }
 906
 907 struct sk_buff *tipc_nametbl_get(const void *req_tlv_area, int req_tlv_space)
 908 {
 909         struct sk_buff *buf;
 910         struct tipc_name_table_query *argv;
 911         struct tlv_desc *rep_tlv;
 912         char *pb;
 913         int pb_len;
 914         int str_len;
 915
 916         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NAME_TBL_QUERY))
 917                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 918
 919         buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
 920         if (!buf)
 921                 return NULL;
 922
 923         rep_tlv = (struct tlv_desc *)buf->data;
 924         pb = TLV_DATA(rep_tlv);
 925         pb_len = ULTRA_STRING_MAX_LEN;
 926         argv = (struct tipc_name_table_query *)TLV_DATA(req_tlv_area);
 927         read_lock_bh(&tipc_nametbl_lock);
 928         str_len = nametbl_list(pb, pb_len, ntohl(argv->depth),
 929                                ntohl(argv->type),
 930                                ntohl(argv->lowbound), ntohl(argv->upbound));
 931         read_unlock_bh(&tipc_nametbl_lock);
 932         str_len += 1;   /* for "\0" */
 933         skb_put(buf, TLV_SPACE(str_len));
 934         TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
 935
 936         return buf;
 937 }
 938
 939 int tipc_nametbl_init(void)
 940 {
 941         int i;
 942
 943         tipc_nametbl = kzalloc(sizeof(*tipc_nametbl), GFP_ATOMIC);
 944         if (!tipc_nametbl)
 945                 return -ENOMEM;
 946
 947         for (i = 0; i < TIPC_NAMETBL_SIZE; i++)
 948                 INIT_HLIST_HEAD(&tipc_nametbl->seq_hlist[i]);
 949
 950         INIT_LIST_HEAD(&tipc_nametbl->publ_list[TIPC_ZONE_SCOPE]);
 951         INIT_LIST_HEAD(&tipc_nametbl->publ_list[TIPC_CLUSTER_SCOPE]);
 952         INIT_LIST_HEAD(&tipc_nametbl->publ_list[TIPC_NODE_SCOPE]);
 953         return 0;
 954 }
 955
 956 /**
 957  * tipc_purge_publications - remove all publications for a given type
 958  *
 959  * tipc_nametbl_lock must be held when calling this function
 960  */
 961 static void tipc_purge_publications(struct name_seq *seq)
 962 {
 963         struct publication *publ, *safe;
 964         struct sub_seq *sseq;
 965         struct name_info *info;
 966
 967         sseq = seq->sseqs;
 968         info = sseq->info;
 969         list_for_each_entry_safe(publ, safe, &info->zone_list, zone_list) {
 970                 tipc_nametbl_remove_publ(publ->type, publ->lower, publ->node,
 971                                          publ->ref, publ->key);
 972                 kfree(publ);
 973         }
 974         hlist_del_init(&seq->ns_list);
 975         kfree(seq->sseqs);
 976         kfree(seq);
 977 }
 978
 979 void tipc_nametbl_stop(void)
 980 {
 981         u32 i;
 982         struct name_seq *seq;
 983         struct hlist_head *seq_head;
 984         struct hlist_node *safe;
 985
 986         /* Verify name table is empty and purge any lingering
 987          * publications, then release the name table
 988          */
 989         write_lock_bh(&tipc_nametbl_lock);
 990         for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
 991                 if (hlist_empty(&tipc_nametbl->seq_hlist[i]))
 992                         continue;
 993                 seq_head = &tipc_nametbl->seq_hlist[i];
 994                 hlist_for_each_entry_safe(seq, safe, seq_head, ns_list) {
 995                         tipc_purge_publications(seq);
 996                 }
 997         }
 998         write_unlock_bh(&tipc_nametbl_lock);
 999
1000         kfree(tipc_nametbl);
1001
1002 }
1003
1004 static int __tipc_nl_add_nametable_publ(struct tipc_nl_msg *msg,
1005                                         struct name_seq *seq,
1006                                         struct sub_seq *sseq, u32 *last_publ)
1007 {
1008         void *hdr;
1009         struct nlattr *attrs;
1010         struct nlattr *publ;
1011         struct publication *p;
1012
1013         if (*last_publ) {
1014                 list_for_each_entry(p, &sseq->info->zone_list, zone_list)
1015                         if (p->key == *last_publ)
1016                                 break;
1017                 if (p->key != *last_publ)
1018                         return -EPIPE;
1019         } else {
1020                 p = list_first_entry(&sseq->info->zone_list, struct publication,
1021                                      zone_list);
1022         }
1023
1024         list_for_each_entry_from(p, &sseq->info->zone_list, zone_list) {
1025                 *last_publ = p->key;
1026
1027                 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq,
1028                                   &tipc_genl_v2_family, NLM_F_MULTI,
1029                                   TIPC_NL_NAME_TABLE_GET);
1030                 if (!hdr)
1031                         return -EMSGSIZE;
1032
1033                 attrs = nla_nest_start(msg->skb, TIPC_NLA_NAME_TABLE);
1034                 if (!attrs)
1035                         goto msg_full;
1036
1037                 publ = nla_nest_start(msg->skb, TIPC_NLA_NAME_TABLE_PUBL);
1038                 if (!publ)
1039                         goto attr_msg_full;
1040
1041                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_TYPE, seq->type))
1042                         goto publ_msg_full;
1043                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_LOWER, sseq->lower))
1044                         goto publ_msg_full;
1045                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_UPPER, sseq->upper))
1046                         goto publ_msg_full;
1047                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_SCOPE, p->scope))
1048                         goto publ_msg_full;
1049                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_NODE, p->node))
1050                         goto publ_msg_full;
1051                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_REF, p->ref))
1052                         goto publ_msg_full;
1053                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_KEY, p->key))
1054                         goto publ_msg_full;
1055
1056                 nla_nest_end(msg->skb, publ);
1057                 nla_nest_end(msg->skb, attrs);
1058                 genlmsg_end(msg->skb, hdr);
1059         }
1060         *last_publ = 0;
1061
1062         return 0;
1063
1064 publ_msg_full:
1065         nla_nest_cancel(msg->skb, publ);
1066 attr_msg_full:
1067         nla_nest_cancel(msg->skb, attrs);
1068 msg_full:
1069         genlmsg_cancel(msg->skb, hdr);
1070
1071         return -EMSGSIZE;
1072 }
1073
1074 static int __tipc_nl_subseq_list(struct tipc_nl_msg *msg, struct name_seq *seq,
1075                                  u32 *last_lower, u32 *last_publ)
1076 {
1077         struct sub_seq *sseq;
1078         struct sub_seq *sseq_start;
1079         int err;
1080
1081         if (*last_lower) {
1082                 sseq_start = nameseq_find_subseq(seq, *last_lower);
1083                 if (!sseq_start)
1084                         return -EPIPE;
1085         } else {
1086                 sseq_start = seq->sseqs;
1087         }
1088
1089         for (sseq = sseq_start; sseq != &seq->sseqs[seq->first_free]; sseq++) {
1090                 err = __tipc_nl_add_nametable_publ(msg, seq, sseq, last_publ);
1091                 if (err) {
1092                         *last_lower = sseq->lower;
1093                         return err;
1094                 }
1095         }
1096         *last_lower = 0;
1097
1098         return 0;
1099 }
1100
1101 static int __tipc_nl_seq_list(struct tipc_nl_msg *msg, u32 *last_type,
1102                               u32 *last_lower, u32 *last_publ)
1103 {
1104         struct hlist_head *seq_head;
1105         struct name_seq *seq;
1106         int err;
1107         int i;
1108
1109         if (*last_type)
1110                 i = hash(*last_type);
1111         else
1112                 i = 0;
1113
1114         for (; i < TIPC_NAMETBL_SIZE; i++) {
1115                 seq_head = &tipc_nametbl->seq_hlist[i];
1116
1117                 if (*last_type) {
1118                         seq = nametbl_find_seq(*last_type);
1119                         if (!seq)
1120                                 return -EPIPE;
1121                 } else {
1122                         seq = hlist_entry_safe((seq_head)->first,
1123                                                struct name_seq, ns_list);
1124                         if (!seq)
1125                                 continue;
1126                 }
1127
1128                 hlist_for_each_entry_from(seq, ns_list) {
1129                         spin_lock_bh(&seq->lock);
1130
1131                         err = __tipc_nl_subseq_list(msg, seq, last_lower,
1132                                                     last_publ);
1133
1134                         if (err) {
1135                                 *last_type = seq->type;
1136                                 spin_unlock_bh(&seq->lock);
1137                                 return err;
1138                         }
1139                         spin_unlock_bh(&seq->lock);
1140                 }
1141                 *last_type = 0;
1142         }
1143         return 0;
1144 }
1145
1146 int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
1147 {
1148         int err;
1149         int done = cb->args[3];
1150         u32 last_type = cb->args[0];
1151         u32 last_lower = cb->args[1];
1152         u32 last_publ = cb->args[2];
1153         struct tipc_nl_msg msg;
1154
1155         if (done)
1156                 return 0;
1157
1158         msg.skb = skb;
1159         msg.portid = NETLINK_CB(cb->skb).portid;
1160         msg.seq = cb->nlh->nlmsg_seq;
1161
1162         read_lock_bh(&tipc_nametbl_lock);
1163
1164         err = __tipc_nl_seq_list(&msg, &last_type, &last_lower, &last_publ);
1165         if (!err) {
1166                 done = 1;
1167         } else if (err != -EMSGSIZE) {
1168                 /* We never set seq or call nl_dump_check_consistent() this
1169                  * means that setting prev_seq here will cause the consistence
1170                  * check to fail in the netlink callback handler. Resulting in
1171                  * the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if
1172                  * we got an error.
1173                  */
1174                 cb->prev_seq = 1;
1175         }
1176
1177         read_unlock_bh(&tipc_nametbl_lock);
1178
1179         cb->args[0] = last_type;
1180         cb->args[1] = last_lower;
1181         cb->args[2] = last_publ;
1182         cb->args[3] = done;
1183
1184         return skb->len;
1185 }