contrib/bind9/lib/dns/ecdb.c

   1 /*
   2  * Copyright (C) 2009-2011  Internet Systems Consortium, Inc. ("ISC")
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
   9  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  10  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  11  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  12  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  13  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  14  * PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 /* $Id: ecdb.c,v 1.8 2011-01-14 00:51:43 tbox Exp $ */
  18
  19 #include "config.h"
  20
  21 #include <isc/result.h>
  22 #include <isc/util.h>
  23 #include <isc/mutex.h>
  24 #include <isc/mem.h>
  25
  26 #include <dns/db.h>
  27 #include <dns/ecdb.h>
  28 #include <dns/rdata.h>
  29 #include <dns/rdataset.h>
  30 #include <dns/rdatasetiter.h>
  31 #include <dns/rdataslab.h>
  32
  33 #define ECDB_MAGIC              ISC_MAGIC('E', 'C', 'D', 'B')
  34 #define VALID_ECDB(db)          ((db) != NULL && \
  35                                  (db)->common.impmagic == ECDB_MAGIC)
  36
  37 #define ECDBNODE_MAGIC          ISC_MAGIC('E', 'C', 'D', 'N')
  38 #define VALID_ECDBNODE(ecdbn)   ISC_MAGIC_VALID(ecdbn, ECDBNODE_MAGIC)
  39
  40 #if DNS_RDATASET_FIXED
  41 #error "Fixed rdataset isn't supported in this implementation"
  42 #endif
  43
  44 /*%
  45  * The 'ephemeral' cache DB (ecdb) implementation.  An ecdb just provides
  46  * temporary storage for ongoing name resolution with the common DB interfaces.
  47  * It actually doesn't cache anything.  The implementation expects any stored
  48  * data is released within a short period, and does not care about the
  49  * scalability in terms of the number of nodes.
  50  */
  51
  52 typedef struct dns_ecdb {
  53         /* Unlocked */
  54         dns_db_t                        common;
  55         isc_mutex_t                     lock;
  56
  57         /* Locked */
  58         unsigned int                    references;
  59         ISC_LIST(struct dns_ecdbnode)   nodes;
  60 } dns_ecdb_t;
  61
  62 typedef struct dns_ecdbnode {
  63         /* Unlocked */
  64         unsigned int                    magic;
  65         isc_mutex_t                     lock;
  66         dns_ecdb_t                      *ecdb;
  67         dns_name_t                      name;
  68         ISC_LINK(struct dns_ecdbnode)   link;
  69
  70         /* Locked */
  71         ISC_LIST(struct rdatasetheader) rdatasets;
  72         unsigned int                    references;
  73 } dns_ecdbnode_t;
  74
  75 typedef struct rdatasetheader {
  76         dns_rdatatype_t                 type;
  77         dns_ttl_t                       ttl;
  78         dns_trust_t                     trust;
  79         dns_rdatatype_t                 covers;
  80         unsigned int                    attributes;
  81
  82         ISC_LINK(struct rdatasetheader) link;
  83 } rdatasetheader_t;
  84
  85 /* Copied from rbtdb.c */
  86 #define RDATASET_ATTR_NXDOMAIN          0x0010
  87 #define NXDOMAIN(header) \
  88         (((header)->attributes & RDATASET_ATTR_NXDOMAIN) != 0)
  89
  90 static isc_result_t dns_ecdb_create(isc_mem_t *mctx, dns_name_t *origin,
  91                                     dns_dbtype_t type,
  92                                     dns_rdataclass_t rdclass,
  93                                     unsigned int argc, char *argv[],
  94                                     void *driverarg, dns_db_t **dbp);
  95
  96 static void rdataset_disassociate(dns_rdataset_t *rdataset);
  97 static isc_result_t rdataset_first(dns_rdataset_t *rdataset);
  98 static isc_result_t rdataset_next(dns_rdataset_t *rdataset);
  99 static void rdataset_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata);
 100 static void rdataset_clone(dns_rdataset_t *source, dns_rdataset_t *target);
 101 static unsigned int rdataset_count(dns_rdataset_t *rdataset);
 102 static void rdataset_settrust(dns_rdataset_t *rdataset, dns_trust_t trust);
 103
 104 static dns_rdatasetmethods_t rdataset_methods = {
 105         rdataset_disassociate,
 106         rdataset_first,
 107         rdataset_next,
 108         rdataset_current,
 109         rdataset_clone,
 110         rdataset_count,
 111         NULL,                   /* addnoqname */
 112         NULL,                   /* getnoqname */
 113         NULL,                   /* addclosest */
 114         NULL,                   /* getclosest */
 115         NULL,                   /* getadditional */
 116         NULL,                   /* setadditional */
 117         NULL,                   /* putadditional */
 118         rdataset_settrust,      /* settrust */
 119         NULL                    /* expire */
 120 };
 121
 122 typedef struct ecdb_rdatasetiter {
 123         dns_rdatasetiter_t              common;
 124         rdatasetheader_t               *current;
 125 } ecdb_rdatasetiter_t;
 126
 127 static void             rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp);
 128 static isc_result_t     rdatasetiter_first(dns_rdatasetiter_t *iterator);
 129 static isc_result_t     rdatasetiter_next(dns_rdatasetiter_t *iterator);
 130 static void             rdatasetiter_current(dns_rdatasetiter_t *iterator,
 131                                              dns_rdataset_t *rdataset);
 132
 133 static dns_rdatasetitermethods_t rdatasetiter_methods = {
 134         rdatasetiter_destroy,
 135         rdatasetiter_first,
 136         rdatasetiter_next,
 137         rdatasetiter_current
 138 };
 139
 140 isc_result_t
 141 dns_ecdb_register(isc_mem_t *mctx, dns_dbimplementation_t **dbimp) {
 142         REQUIRE(mctx != NULL);
 143         REQUIRE(dbimp != NULL && *dbimp == NULL);
 144
 145         return (dns_db_register("ecdb", dns_ecdb_create, NULL, mctx, dbimp));
 146 }
 147
 148 void
 149 dns_ecdb_unregister(dns_dbimplementation_t **dbimp) {
 150         REQUIRE(dbimp != NULL && *dbimp != NULL);
 151
 152         dns_db_unregister(dbimp);
 153 }
 154
 155 /*%
 156  * DB routines
 157  */
 158
 159 static void
 160 attach(dns_db_t *source, dns_db_t **targetp) {
 161         dns_ecdb_t *ecdb = (dns_ecdb_t *)source;
 162
 163         REQUIRE(VALID_ECDB(ecdb));
 164         REQUIRE(targetp != NULL && *targetp == NULL);
 165
 166         LOCK(&ecdb->lock);
 167         ecdb->references++;
 168         UNLOCK(&ecdb->lock);
 169
 170         *targetp = source;
 171 }
 172
 173 static void
 174 destroy_ecdb(dns_ecdb_t **ecdbp) {
 175         dns_ecdb_t *ecdb = *ecdbp;
 176         isc_mem_t *mctx = ecdb->common.mctx;
 177
 178         if (dns_name_dynamic(&ecdb->common.origin))
 179                 dns_name_free(&ecdb->common.origin, mctx);
 180
 181         DESTROYLOCK(&ecdb->lock);
 182
 183         ecdb->common.impmagic = 0;
 184         ecdb->common.magic = 0;
 185
 186         isc_mem_putanddetach(&mctx, ecdb, sizeof(*ecdb));
 187
 188         *ecdbp = NULL;
 189 }
 190
 191 static void
 192 detach(dns_db_t **dbp) {
 193         dns_ecdb_t *ecdb;
 194         isc_boolean_t need_destroy = ISC_FALSE;
 195
 196         REQUIRE(dbp != NULL);
 197         ecdb = (dns_ecdb_t *)*dbp;
 198         REQUIRE(VALID_ECDB(ecdb));
 199
 200         LOCK(&ecdb->lock);
 201         ecdb->references--;
 202         if (ecdb->references == 0 && ISC_LIST_EMPTY(ecdb->nodes))
 203                 need_destroy = ISC_TRUE;
 204         UNLOCK(&ecdb->lock);
 205
 206         if (need_destroy)
 207                 destroy_ecdb(&ecdb);
 208
 209         *dbp = NULL;
 210 }
 211
 212 static void
 213 attachnode(dns_db_t *db, dns_dbnode_t *source, dns_dbnode_t **targetp) {
 214         dns_ecdb_t *ecdb = (dns_ecdb_t *)db;
 215         dns_ecdbnode_t *node = (dns_ecdbnode_t *)source;
 216
 217         REQUIRE(VALID_ECDB(ecdb));
 218         REQUIRE(VALID_ECDBNODE(node));
 219         REQUIRE(targetp != NULL && *targetp == NULL);
 220
 221         LOCK(&node->lock);
 222         INSIST(node->references > 0);
 223         node->references++;
 224         INSIST(node->references != 0);          /* Catch overflow. */
 225         UNLOCK(&node->lock);
 226
 227         *targetp = node;
 228 }
 229
 230 static void
 231 destroynode(dns_ecdbnode_t *node) {
 232         isc_mem_t *mctx;
 233         dns_ecdb_t *ecdb = node->ecdb;
 234         isc_boolean_t need_destroydb = ISC_FALSE;
 235         rdatasetheader_t *header;
 236
 237         mctx = ecdb->common.mctx;
 238
 239         LOCK(&ecdb->lock);
 240         ISC_LIST_UNLINK(ecdb->nodes, node, link);
 241         if (ecdb->references == 0 && ISC_LIST_EMPTY(ecdb->nodes))
 242                 need_destroydb = ISC_TRUE;
 243         UNLOCK(&ecdb->lock);
 244
 245         dns_name_free(&node->name, mctx);
 246
 247         while ((header = ISC_LIST_HEAD(node->rdatasets)) != NULL) {
 248                 unsigned int headersize;
 249
 250                 ISC_LIST_UNLINK(node->rdatasets, header, link);
 251                 headersize =
 252                         dns_rdataslab_size((unsigned char *)header,
 253                                            sizeof(*header));
 254                 isc_mem_put(mctx, header, headersize);
 255         }
 256
 257         DESTROYLOCK(&node->lock);
 258
 259         node->magic = 0;
 260         isc_mem_put(mctx, node, sizeof(*node));
 261
 262         if (need_destroydb)
 263                 destroy_ecdb(&ecdb);
 264 }
 265
 266 static void
 267 detachnode(dns_db_t *db, dns_dbnode_t **nodep) {
 268         dns_ecdb_t *ecdb = (dns_ecdb_t *)db;
 269         dns_ecdbnode_t *node;
 270         isc_boolean_t need_destroy = ISC_FALSE;
 271
 272         REQUIRE(VALID_ECDB(ecdb));
 273         REQUIRE(nodep != NULL);
 274         node = (dns_ecdbnode_t *)*nodep;
 275         REQUIRE(VALID_ECDBNODE(node));
 276
 277         UNUSED(ecdb);           /* in case REQUIRE() is empty */
 278
 279         LOCK(&node->lock);
 280         INSIST(node->references > 0);
 281         node->references--;
 282         if (node->references == 0)
 283                 need_destroy = ISC_TRUE;
 284         UNLOCK(&node->lock);
 285
 286         if (need_destroy)
 287                 destroynode(node);
 288
 289         *nodep = NULL;
 290 }
 291
 292 static isc_result_t
 293 find(dns_db_t *db, dns_name_t *name, dns_dbversion_t *version,
 294     dns_rdatatype_t type, unsigned int options, isc_stdtime_t now,
 295     dns_dbnode_t **nodep, dns_name_t *foundname, dns_rdataset_t *rdataset,
 296     dns_rdataset_t *sigrdataset)
 297 {
 298         dns_ecdb_t *ecdb = (dns_ecdb_t *)db;
 299
 300         REQUIRE(VALID_ECDB(ecdb));
 301
 302         UNUSED(name);
 303         UNUSED(version);
 304         UNUSED(type);
 305         UNUSED(options);
 306         UNUSED(now);
 307         UNUSED(nodep);
 308         UNUSED(foundname);
 309         UNUSED(rdataset);
 310         UNUSED(sigrdataset);
 311
 312         return (ISC_R_NOTFOUND);
 313 }
 314
 315 static isc_result_t
 316 findzonecut(dns_db_t *db, dns_name_t *name,
 317             unsigned int options, isc_stdtime_t now,
 318             dns_dbnode_t **nodep, dns_name_t *foundname,
 319             dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset)
 320 {
 321         dns_ecdb_t *ecdb = (dns_ecdb_t *)db;
 322
 323         REQUIRE(VALID_ECDB(ecdb));
 324
 325         UNUSED(name);
 326         UNUSED(options);
 327         UNUSED(now);
 328         UNUSED(nodep);
 329         UNUSED(foundname);
 330         UNUSED(rdataset);
 331         UNUSED(sigrdataset);
 332
 333         return (ISC_R_NOTFOUND);
 334 }
 335
 336 static isc_result_t
 337 findnode(dns_db_t *db, dns_name_t *name, isc_boolean_t create,
 338          dns_dbnode_t **nodep)
 339 {
 340         dns_ecdb_t *ecdb = (dns_ecdb_t *)db;
 341         isc_mem_t *mctx;
 342         dns_ecdbnode_t *node;
 343         isc_result_t result;
 344
 345         REQUIRE(VALID_ECDB(ecdb));
 346         REQUIRE(nodep != NULL && *nodep == NULL);
 347
 348         UNUSED(name);
 349
 350         if (create != ISC_TRUE) {
 351                 /* an 'ephemeral' node is never reused. */
 352                 return (ISC_R_NOTFOUND);
 353         }
 354
 355         mctx = ecdb->common.mctx;
 356         node = isc_mem_get(mctx, sizeof(*node));
 357         if (node == NULL)
 358                 return (ISC_R_NOMEMORY);
 359
 360         result = isc_mutex_init(&node->lock);
 361         if (result != ISC_R_SUCCESS) {
 362                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 363                                  "isc_mutex_init() failed: %s",
 364                                  isc_result_totext(result));
 365                 isc_mem_put(mctx, node, sizeof(*node));
 366                 return (ISC_R_UNEXPECTED);
 367         }
 368
 369         dns_name_init(&node->name, NULL);
 370         result = dns_name_dup(name, mctx, &node->name);
 371         if (result != ISC_R_SUCCESS) {
 372                 DESTROYLOCK(&node->lock);
 373                 isc_mem_put(mctx, node, sizeof(*node));
 374                 return (result);
 375         }
 376         node->ecdb= ecdb;
 377         node->references = 1;
 378         ISC_LIST_INIT(node->rdatasets);
 379
 380         ISC_LINK_INIT(node, link);
 381
 382         LOCK(&ecdb->lock);
 383         ISC_LIST_APPEND(ecdb->nodes, node, link);
 384         UNLOCK(&ecdb->lock);
 385
 386         node->magic = ECDBNODE_MAGIC;
 387
 388         *nodep = node;
 389
 390         return (ISC_R_SUCCESS);
 391 }
 392
 393 static void
 394 bind_rdataset(dns_ecdb_t *ecdb, dns_ecdbnode_t *node,
 395               rdatasetheader_t *header, dns_rdataset_t *rdataset)
 396 {
 397         unsigned char *raw;
 398
 399         /*
 400          * Caller must be holding the node lock.
 401          */
 402
 403         REQUIRE(!dns_rdataset_isassociated(rdataset));
 404
 405         rdataset->methods = &rdataset_methods;
 406         rdataset->rdclass = ecdb->common.rdclass;
 407         rdataset->type = header->type;
 408         rdataset->covers = header->covers;
 409         rdataset->ttl = header->ttl;
 410         rdataset->trust = header->trust;
 411         if (NXDOMAIN(header))
 412                 rdataset->attributes |= DNS_RDATASETATTR_NXDOMAIN;
 413
 414         rdataset->private1 = ecdb;
 415         rdataset->private2 = node;
 416         raw = (unsigned char *)header + sizeof(*header);
 417         rdataset->private3 = raw;
 418         rdataset->count = 0;
 419
 420         /*
 421          * Reset iterator state.
 422          */
 423         rdataset->privateuint4 = 0;
 424         rdataset->private5 = NULL;
 425
 426         INSIST(node->references > 0);
 427         node->references++;
 428 }
 429
 430 static isc_result_t
 431 addrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
 432             isc_stdtime_t now, dns_rdataset_t *rdataset, unsigned int options,
 433             dns_rdataset_t *addedrdataset)
 434 {
 435         dns_ecdb_t *ecdb = (dns_ecdb_t *)db;
 436         isc_region_t r;
 437         isc_result_t result = ISC_R_SUCCESS;
 438         isc_mem_t *mctx;
 439         dns_ecdbnode_t *ecdbnode = (dns_ecdbnode_t *)node;
 440         rdatasetheader_t *header;
 441
 442         REQUIRE(VALID_ECDB(ecdb));
 443         REQUIRE(VALID_ECDBNODE(ecdbnode));
 444
 445         UNUSED(version);
 446         UNUSED(now);
 447         UNUSED(options);
 448
 449         mctx = ecdb->common.mctx;
 450
 451         LOCK(&ecdbnode->lock);
 452
 453         /*
 454          * Sanity check: this implementation does not allow overriding an
 455          * existing rdataset of the same type.
 456          */
 457         for (header = ISC_LIST_HEAD(ecdbnode->rdatasets); header != NULL;
 458              header = ISC_LIST_NEXT(header, link)) {
 459                 INSIST(header->type != rdataset->type ||
 460                        header->covers != rdataset->covers);
 461         }
 462
 463         result = dns_rdataslab_fromrdataset(rdataset, mctx,
 464                                             &r, sizeof(rdatasetheader_t));
 465         if (result != ISC_R_SUCCESS)
 466                 goto unlock;
 467
 468         header = (rdatasetheader_t *)r.base;
 469         header->type = rdataset->type;
 470         header->ttl = rdataset->ttl;
 471         header->trust = rdataset->trust;
 472         header->covers = rdataset->covers;
 473         header->attributes = 0;
 474         if ((rdataset->attributes & DNS_RDATASETATTR_NXDOMAIN) != 0)
 475                 header->attributes |= RDATASET_ATTR_NXDOMAIN;
 476         ISC_LINK_INIT(header, link);
 477         ISC_LIST_APPEND(ecdbnode->rdatasets, header, link);
 478
 479         if (addedrdataset == NULL)
 480                 goto unlock;
 481
 482         bind_rdataset(ecdb, ecdbnode, header, addedrdataset);
 483
 484  unlock:
 485         UNLOCK(&ecdbnode->lock);
 486
 487         return (result);
 488 }
 489
 490 static isc_result_t
 491 deleterdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
 492                dns_rdatatype_t type, dns_rdatatype_t covers)
 493 {
 494         UNUSED(db);
 495         UNUSED(node);
 496         UNUSED(version);
 497         UNUSED(type);
 498         UNUSED(covers);
 499
 500         return (ISC_R_NOTIMPLEMENTED);
 501 }
 502
 503 static isc_result_t
 504 createiterator(dns_db_t *db, unsigned int options,
 505                dns_dbiterator_t **iteratorp)
 506 {
 507         UNUSED(db);
 508         UNUSED(options);
 509         UNUSED(iteratorp);
 510
 511         return (ISC_R_NOTIMPLEMENTED);
 512 }
 513
 514 static isc_result_t
 515 allrdatasets(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
 516              isc_stdtime_t now, dns_rdatasetiter_t **iteratorp)
 517 {
 518         dns_ecdb_t *ecdb = (dns_ecdb_t *)db;
 519         dns_ecdbnode_t *ecdbnode = (dns_ecdbnode_t *)node;
 520         isc_mem_t *mctx;
 521         ecdb_rdatasetiter_t *iterator;
 522
 523         REQUIRE(VALID_ECDB(ecdb));
 524         REQUIRE(VALID_ECDBNODE(ecdbnode));
 525
 526         mctx = ecdb->common.mctx;
 527
 528         iterator = isc_mem_get(mctx, sizeof(ecdb_rdatasetiter_t));
 529         if (iterator == NULL)
 530                 return (ISC_R_NOMEMORY);
 531
 532         iterator->common.magic = DNS_RDATASETITER_MAGIC;
 533         iterator->common.methods = &rdatasetiter_methods;
 534         iterator->common.db = db;
 535         iterator->common.node = NULL;
 536         attachnode(db, node, &iterator->common.node);
 537         iterator->common.version = version;
 538         iterator->common.now = now;
 539
 540         *iteratorp = (dns_rdatasetiter_t *)iterator;
 541
 542         return (ISC_R_SUCCESS);
 543 }
 544
 545 static dns_dbmethods_t ecdb_methods = {
 546         attach,
 547         detach,
 548         NULL,                   /* beginload */
 549         NULL,                   /* endload */
 550         NULL,                   /* dump */
 551         NULL,                   /* currentversion */
 552         NULL,                   /* newversion */
 553         NULL,                   /* attachversion */
 554         NULL,                   /* closeversion */
 555         findnode,
 556         find,
 557         findzonecut,
 558         attachnode,
 559         detachnode,
 560         NULL,                   /* expirenode */
 561         NULL,                   /* printnode */
 562         createiterator,         /* createiterator */
 563         NULL,                   /* findrdataset */
 564         allrdatasets,
 565         addrdataset,
 566         NULL,                   /* subtractrdataset */
 567         deleterdataset,
 568         NULL,                   /* issecure */
 569         NULL,                   /* nodecount */
 570         NULL,                   /* ispersistent */
 571         NULL,                   /* overmem */
 572         NULL,                   /* settask */
 573         NULL,                   /* getoriginnode */
 574         NULL,                   /* transfernode */
 575         NULL,                   /* getnsec3parameters */
 576         NULL,                   /* findnsec3node */
 577         NULL,                   /* setsigningtime */
 578         NULL,                   /* getsigningtime */
 579         NULL,                   /* resigned */
 580         NULL,                   /* isdnssec */
 581         NULL,                   /* getrrsetstats */
 582         NULL,                   /* rpz_enabled */
 583         NULL                    /* rpz_findips */
 584 };
 585
 586 static isc_result_t
 587 dns_ecdb_create(isc_mem_t *mctx, dns_name_t *origin, dns_dbtype_t type,
 588                 dns_rdataclass_t rdclass, unsigned int argc, char *argv[],
 589                 void *driverarg, dns_db_t **dbp)
 590 {
 591         dns_ecdb_t *ecdb;
 592         isc_result_t result;
 593
 594         REQUIRE(mctx != NULL);
 595         REQUIRE(origin == dns_rootname);
 596         REQUIRE(type == dns_dbtype_cache);
 597         REQUIRE(dbp != NULL && *dbp == NULL);
 598
 599         UNUSED(argc);
 600         UNUSED(argv);
 601         UNUSED(driverarg);
 602
 603         ecdb = isc_mem_get(mctx, sizeof(*ecdb));
 604         if (ecdb == NULL)
 605                 return (ISC_R_NOMEMORY);
 606
 607         ecdb->common.attributes = DNS_DBATTR_CACHE;
 608         ecdb->common.rdclass = rdclass;
 609         ecdb->common.methods = &ecdb_methods;
 610         dns_name_init(&ecdb->common.origin, NULL);
 611         result = dns_name_dupwithoffsets(origin, mctx, &ecdb->common.origin);
 612         if (result != ISC_R_SUCCESS) {
 613                 isc_mem_put(mctx, ecdb, sizeof(*ecdb));
 614                 return (result);
 615         }
 616
 617         result = isc_mutex_init(&ecdb->lock);
 618         if (result != ISC_R_SUCCESS) {
 619                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 620                                  "isc_mutex_init() failed: %s",
 621                                  isc_result_totext(result));
 622                 if (dns_name_dynamic(&ecdb->common.origin))
 623                         dns_name_free(&ecdb->common.origin, mctx);
 624                 isc_mem_put(mctx, ecdb, sizeof(*ecdb));
 625                 return (ISC_R_UNEXPECTED);
 626         }
 627
 628         ecdb->references = 1;
 629         ISC_LIST_INIT(ecdb->nodes);
 630
 631         ecdb->common.mctx = NULL;
 632         isc_mem_attach(mctx, &ecdb->common.mctx);
 633         ecdb->common.impmagic = ECDB_MAGIC;
 634         ecdb->common.magic = DNS_DB_MAGIC;
 635
 636         *dbp = (dns_db_t *)ecdb;
 637
 638         return (ISC_R_SUCCESS);
 639 }
 640
 641 /*%
 642  * Rdataset Methods
 643  */
 644
 645 static void
 646 rdataset_disassociate(dns_rdataset_t *rdataset) {
 647         dns_db_t *db = rdataset->private1;
 648         dns_dbnode_t *node = rdataset->private2;
 649
 650         dns_db_detachnode(db, &node);
 651 }
 652
 653 static isc_result_t
 654 rdataset_first(dns_rdataset_t *rdataset) {
 655         unsigned char *raw = rdataset->private3;
 656         unsigned int count;
 657
 658         count = raw[0] * 256 + raw[1];
 659         if (count == 0) {
 660                 rdataset->private5 = NULL;
 661                 return (ISC_R_NOMORE);
 662         }
 663         raw += 2;
 664         /*
 665          * The privateuint4 field is the number of rdata beyond the cursor
 666          * position, so we decrement the total count by one before storing
 667          * it.
 668          */
 669         count--;
 670         rdataset->privateuint4 = count;
 671         rdataset->private5 = raw;
 672
 673         return (ISC_R_SUCCESS);
 674 }
 675
 676 static isc_result_t
 677 rdataset_next(dns_rdataset_t *rdataset) {
 678         unsigned int count;
 679         unsigned int length;
 680         unsigned char *raw;
 681
 682         count = rdataset->privateuint4;
 683         if (count == 0)
 684                 return (ISC_R_NOMORE);
 685         count--;
 686         rdataset->privateuint4 = count;
 687         raw = rdataset->private5;
 688         length = raw[0] * 256 + raw[1];
 689         raw += length + 2;
 690         rdataset->private5 = raw;
 691
 692         return (ISC_R_SUCCESS);
 693 }
 694
 695 static void
 696 rdataset_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata) {
 697         unsigned char *raw = rdataset->private5;
 698         isc_region_t r;
 699         unsigned int length;
 700         unsigned int flags = 0;
 701
 702         REQUIRE(raw != NULL);
 703
 704         length = raw[0] * 256 + raw[1];
 705         raw += 2;
 706         if (rdataset->type == dns_rdatatype_rrsig) {
 707                 if (*raw & DNS_RDATASLAB_OFFLINE)
 708                         flags |= DNS_RDATA_OFFLINE;
 709                 length--;
 710                 raw++;
 711         }
 712         r.length = length;
 713         r.base = raw;
 714         dns_rdata_fromregion(rdata, rdataset->rdclass, rdataset->type, &r);
 715         rdata->flags |= flags;
 716 }
 717
 718 static void
 719 rdataset_clone(dns_rdataset_t *source, dns_rdataset_t *target) {
 720         dns_db_t *db = source->private1;
 721         dns_dbnode_t *node = source->private2;
 722         dns_dbnode_t *cloned_node = NULL;
 723
 724         attachnode(db, node, &cloned_node);
 725         *target = *source;
 726
 727         /*
 728          * Reset iterator state.
 729          */
 730         target->privateuint4 = 0;
 731         target->private5 = NULL;
 732 }
 733
 734 static unsigned int
 735 rdataset_count(dns_rdataset_t *rdataset) {
 736         unsigned char *raw = rdataset->private3;
 737         unsigned int count;
 738
 739         count = raw[0] * 256 + raw[1];
 740
 741         return (count);
 742 }
 743
 744 static void
 745 rdataset_settrust(dns_rdataset_t *rdataset, dns_trust_t trust) {
 746         rdatasetheader_t *header = rdataset->private3;
 747
 748         header--;
 749         header->trust = rdataset->trust = trust;
 750 }
 751
 752 /*
 753  * Rdataset Iterator Methods
 754  */
 755
 756 static void
 757 rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp) {
 758         ecdb_rdatasetiter_t *ecdbiterator;
 759         isc_mem_t *mctx;
 760
 761         REQUIRE(iteratorp != NULL);
 762         ecdbiterator = (ecdb_rdatasetiter_t *)*iteratorp;
 763         REQUIRE(DNS_RDATASETITER_VALID(&ecdbiterator->common));
 764
 765         mctx = ecdbiterator->common.db->mctx;
 766
 767         ecdbiterator->common.magic = 0;
 768
 769         dns_db_detachnode(ecdbiterator->common.db, &ecdbiterator->common.node);
 770         isc_mem_put(mctx, ecdbiterator, sizeof(ecdb_rdatasetiter_t));
 771
 772         *iteratorp = NULL;
 773 }
 774
 775 static isc_result_t
 776 rdatasetiter_first(dns_rdatasetiter_t *iterator) {
 777         ecdb_rdatasetiter_t *ecdbiterator = (ecdb_rdatasetiter_t *)iterator;
 778         dns_ecdbnode_t *ecdbnode = (dns_ecdbnode_t *)iterator->node;
 779
 780         REQUIRE(DNS_RDATASETITER_VALID(iterator));
 781
 782         if (ISC_LIST_EMPTY(ecdbnode->rdatasets))
 783                 return (ISC_R_NOMORE);
 784         ecdbiterator->current = ISC_LIST_HEAD(ecdbnode->rdatasets);
 785         return (ISC_R_SUCCESS);
 786 }
 787
 788 static isc_result_t
 789 rdatasetiter_next(dns_rdatasetiter_t *iterator) {
 790         ecdb_rdatasetiter_t *ecdbiterator = (ecdb_rdatasetiter_t *)iterator;
 791
 792         REQUIRE(DNS_RDATASETITER_VALID(iterator));
 793
 794         ecdbiterator->current = ISC_LIST_NEXT(ecdbiterator->current, link);
 795         if (ecdbiterator->current == NULL)
 796                 return (ISC_R_NOMORE);
 797         else
 798                 return (ISC_R_SUCCESS);
 799 }
 800
 801 static void
 802 rdatasetiter_current(dns_rdatasetiter_t *iterator, dns_rdataset_t *rdataset) {
 803         ecdb_rdatasetiter_t *ecdbiterator = (ecdb_rdatasetiter_t *)iterator;
 804         dns_ecdb_t *ecdb;
 805
 806         ecdb = (dns_ecdb_t *)iterator->db;
 807         REQUIRE(VALID_ECDB(ecdb));
 808
 809         bind_rdataset(ecdb, iterator->node, ecdbiterator->current, rdataset);
 810 }