contrib/bind9/lib/dns/db.c

   1 /*
   2  * Copyright (C) 2004, 2005  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1999-2001, 2003  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: db.c,v 1.74.18.6 2005/10/13 02:12:24 marka Exp $ */
  19
  20 /*! \file */
  21
  22 /***
  23  *** Imports
  24  ***/
  25
  26 #include <config.h>
  27
  28 #include <isc/buffer.h>
  29 #include <isc/mem.h>
  30 #include <isc/once.h>
  31 #include <isc/rwlock.h>
  32 #include <isc/string.h>
  33 #include <isc/util.h>
  34
  35 #include <dns/callbacks.h>
  36 #include <dns/db.h>
  37 #include <dns/log.h>
  38 #include <dns/master.h>
  39 #include <dns/rdata.h>
  40 #include <dns/rdataset.h>
  41 #include <dns/result.h>
  42
  43 /***
  44  *** Private Types
  45  ***/
  46
  47 struct dns_dbimplementation {
  48         const char *                            name;
  49         dns_dbcreatefunc_t                      create;
  50         isc_mem_t *                             mctx;
  51         void *                                  driverarg;
  52         ISC_LINK(dns_dbimplementation_t)        link;
  53 };
  54
  55 /***
  56  *** Supported DB Implementations Registry
  57  ***/
  58
  59 /*
  60  * Built in database implementations are registered here.
  61  */
  62
  63 #include "rbtdb.h"
  64 #include "rbtdb64.h"
  65
  66 static ISC_LIST(dns_dbimplementation_t) implementations;
  67 static isc_rwlock_t implock;
  68 static isc_once_t once = ISC_ONCE_INIT;
  69
  70 static dns_dbimplementation_t rbtimp;
  71 static dns_dbimplementation_t rbt64imp;
  72
  73 static void
  74 initialize(void) {
  75         RUNTIME_CHECK(isc_rwlock_init(&implock, 0, 0) == ISC_R_SUCCESS);
  76
  77         rbtimp.name = "rbt";
  78         rbtimp.create = dns_rbtdb_create;
  79         rbtimp.mctx = NULL;
  80         rbtimp.driverarg = NULL;
  81         ISC_LINK_INIT(&rbtimp, link);
  82
  83         rbt64imp.name = "rbt64";
  84         rbt64imp.create = dns_rbtdb64_create;
  85         rbt64imp.mctx = NULL;
  86         rbt64imp.driverarg = NULL;
  87         ISC_LINK_INIT(&rbt64imp, link);
  88
  89         ISC_LIST_INIT(implementations);
  90         ISC_LIST_APPEND(implementations, &rbtimp, link);
  91         ISC_LIST_APPEND(implementations, &rbt64imp, link);
  92 }
  93
  94 static inline dns_dbimplementation_t *
  95 impfind(const char *name) {
  96         dns_dbimplementation_t *imp;
  97
  98         for (imp = ISC_LIST_HEAD(implementations);
  99              imp != NULL;
 100              imp = ISC_LIST_NEXT(imp, link))
 101                 if (strcasecmp(name, imp->name) == 0)
 102                         return (imp);
 103         return (NULL);
 104 }
 105
 106
 107 /***
 108  *** Basic DB Methods
 109  ***/
 110
 111 isc_result_t
 112 dns_db_create(isc_mem_t *mctx, const char *db_type, dns_name_t *origin,
 113               dns_dbtype_t type, dns_rdataclass_t rdclass,
 114               unsigned int argc, char *argv[], dns_db_t **dbp)
 115 {
 116         dns_dbimplementation_t *impinfo;
 117
 118         RUNTIME_CHECK(isc_once_do(&once, initialize) == ISC_R_SUCCESS);
 119
 120         /*
 121          * Create a new database using implementation 'db_type'.
 122          */
 123
 124         REQUIRE(dbp != NULL && *dbp == NULL);
 125         REQUIRE(dns_name_isabsolute(origin));
 126
 127         RWLOCK(&implock, isc_rwlocktype_read);
 128         impinfo = impfind(db_type);
 129         if (impinfo != NULL) {
 130                 isc_result_t result;
 131                 result = ((impinfo->create)(mctx, origin, type,
 132                                             rdclass, argc, argv,
 133                                             impinfo->driverarg, dbp));
 134                 RWUNLOCK(&implock, isc_rwlocktype_read);
 135                 return (result);
 136         }
 137
 138         RWUNLOCK(&implock, isc_rwlocktype_read);
 139
 140         isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
 141                       DNS_LOGMODULE_DB, ISC_LOG_ERROR,
 142                       "unsupported database type '%s'", db_type);
 143
 144         return (ISC_R_NOTFOUND);
 145 }
 146
 147 void
 148 dns_db_attach(dns_db_t *source, dns_db_t **targetp) {
 149
 150         /*
 151          * Attach *targetp to source.
 152          */
 153
 154         REQUIRE(DNS_DB_VALID(source));
 155         REQUIRE(targetp != NULL && *targetp == NULL);
 156
 157         (source->methods->attach)(source, targetp);
 158
 159         ENSURE(*targetp == source);
 160 }
 161
 162 void
 163 dns_db_detach(dns_db_t **dbp) {
 164
 165         /*
 166          * Detach *dbp from its database.
 167          */
 168
 169         REQUIRE(dbp != NULL);
 170         REQUIRE(DNS_DB_VALID(*dbp));
 171
 172         ((*dbp)->methods->detach)(dbp);
 173
 174         ENSURE(*dbp == NULL);
 175 }
 176
 177 isc_result_t
 178 dns_db_ondestroy(dns_db_t *db, isc_task_t *task, isc_event_t **eventp)
 179 {
 180         REQUIRE(DNS_DB_VALID(db));
 181
 182         return (isc_ondestroy_register(&db->ondest, task, eventp));
 183 }
 184
 185
 186 isc_boolean_t
 187 dns_db_iscache(dns_db_t *db) {
 188
 189         /*
 190          * Does 'db' have cache semantics?
 191          */
 192
 193         REQUIRE(DNS_DB_VALID(db));
 194
 195         if ((db->attributes & DNS_DBATTR_CACHE) != 0)
 196                 return (ISC_TRUE);
 197
 198         return (ISC_FALSE);
 199 }
 200
 201 isc_boolean_t
 202 dns_db_iszone(dns_db_t *db) {
 203
 204         /*
 205          * Does 'db' have zone semantics?
 206          */
 207
 208         REQUIRE(DNS_DB_VALID(db));
 209
 210         if ((db->attributes & (DNS_DBATTR_CACHE|DNS_DBATTR_STUB)) == 0)
 211                 return (ISC_TRUE);
 212
 213         return (ISC_FALSE);
 214 }
 215
 216 isc_boolean_t
 217 dns_db_isstub(dns_db_t *db) {
 218
 219         /*
 220          * Does 'db' have stub semantics?
 221          */
 222
 223         REQUIRE(DNS_DB_VALID(db));
 224
 225         if ((db->attributes & DNS_DBATTR_STUB) != 0)
 226                 return (ISC_TRUE);
 227
 228         return (ISC_FALSE);
 229 }
 230
 231 isc_boolean_t
 232 dns_db_issecure(dns_db_t *db) {
 233
 234         /*
 235          * Is 'db' secure?
 236          */
 237
 238         REQUIRE(DNS_DB_VALID(db));
 239         REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
 240
 241         return ((db->methods->issecure)(db));
 242 }
 243
 244 isc_boolean_t
 245 dns_db_ispersistent(dns_db_t *db) {
 246
 247         /*
 248          * Is 'db' persistent?
 249          */
 250
 251         REQUIRE(DNS_DB_VALID(db));
 252
 253         return ((db->methods->ispersistent)(db));
 254 }
 255
 256 dns_name_t *
 257 dns_db_origin(dns_db_t *db) {
 258         /*
 259          * The origin of the database.
 260          */
 261
 262         REQUIRE(DNS_DB_VALID(db));
 263
 264         return (&db->origin);
 265 }
 266
 267 dns_rdataclass_t
 268 dns_db_class(dns_db_t *db) {
 269         /*
 270          * The class of the database.
 271          */
 272
 273         REQUIRE(DNS_DB_VALID(db));
 274
 275         return (db->rdclass);
 276 }
 277
 278 isc_result_t
 279 dns_db_beginload(dns_db_t *db, dns_addrdatasetfunc_t *addp,
 280                  dns_dbload_t **dbloadp) {
 281         /*
 282          * Begin loading 'db'.
 283          */
 284
 285         REQUIRE(DNS_DB_VALID(db));
 286         REQUIRE(addp != NULL && *addp == NULL);
 287         REQUIRE(dbloadp != NULL && *dbloadp == NULL);
 288
 289         return ((db->methods->beginload)(db, addp, dbloadp));
 290 }
 291
 292 isc_result_t
 293 dns_db_endload(dns_db_t *db, dns_dbload_t **dbloadp) {
 294         /*
 295          * Finish loading 'db'.
 296          */
 297
 298         REQUIRE(DNS_DB_VALID(db));
 299         REQUIRE(dbloadp != NULL && *dbloadp != NULL);
 300
 301         return ((db->methods->endload)(db, dbloadp));
 302 }
 303
 304 isc_result_t
 305 dns_db_load(dns_db_t *db, const char *filename) {
 306         return (dns_db_load2(db, filename, dns_masterformat_text));
 307 }
 308
 309 isc_result_t
 310 dns_db_load2(dns_db_t *db, const char *filename, dns_masterformat_t format) {
 311         isc_result_t result, eresult;
 312         dns_rdatacallbacks_t callbacks;
 313         unsigned int options = 0;
 314
 315         /*
 316          * Load master file 'filename' into 'db'.
 317          */
 318
 319         REQUIRE(DNS_DB_VALID(db));
 320
 321         if ((db->attributes & DNS_DBATTR_CACHE) != 0)
 322                 options |= DNS_MASTER_AGETTL;
 323
 324         dns_rdatacallbacks_init(&callbacks);
 325
 326         result = dns_db_beginload(db, &callbacks.add, &callbacks.add_private);
 327         if (result != ISC_R_SUCCESS)
 328                 return (result);
 329         result = dns_master_loadfile2(filename, &db->origin, &db->origin,
 330                                       db->rdclass, options,
 331                                       &callbacks, db->mctx, format);
 332         eresult = dns_db_endload(db, &callbacks.add_private);
 333         /*
 334          * We always call dns_db_endload(), but we only want to return its
 335          * result if dns_master_loadfile() succeeded.  If dns_master_loadfile()
 336          * failed, we want to return the result code it gave us.
 337          */
 338         if (eresult != ISC_R_SUCCESS &&
 339             (result == ISC_R_SUCCESS || result == DNS_R_SEENINCLUDE))
 340                 result = eresult;
 341
 342         return (result);
 343 }
 344
 345 isc_result_t
 346 dns_db_dump(dns_db_t *db, dns_dbversion_t *version, const char *filename) {
 347         return ((db->methods->dump)(db, version, filename,
 348                                     dns_masterformat_text));
 349 }
 350
 351 isc_result_t
 352 dns_db_dump2(dns_db_t *db, dns_dbversion_t *version, const char *filename,
 353              dns_masterformat_t masterformat) {
 354         /*
 355          * Dump 'db' into master file 'filename' in the 'masterformat' format.
 356          * XXXJT: is it okay to modify the interface to the existing "dump"
 357          * method?
 358          */
 359
 360         REQUIRE(DNS_DB_VALID(db));
 361
 362         return ((db->methods->dump)(db, version, filename, masterformat));
 363 }
 364
 365 /***
 366  *** Version Methods
 367  ***/
 368
 369 void
 370 dns_db_currentversion(dns_db_t *db, dns_dbversion_t **versionp) {
 371
 372         /*
 373          * Open the current version for reading.
 374          */
 375
 376         REQUIRE(DNS_DB_VALID(db));
 377         REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
 378         REQUIRE(versionp != NULL && *versionp == NULL);
 379
 380         (db->methods->currentversion)(db, versionp);
 381 }
 382
 383 isc_result_t
 384 dns_db_newversion(dns_db_t *db, dns_dbversion_t **versionp) {
 385
 386         /*
 387          * Open a new version for reading and writing.
 388          */
 389
 390         REQUIRE(DNS_DB_VALID(db));
 391         REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
 392         REQUIRE(versionp != NULL && *versionp == NULL);
 393
 394         return ((db->methods->newversion)(db, versionp));
 395 }
 396
 397 void
 398 dns_db_attachversion(dns_db_t *db, dns_dbversion_t *source,
 399                      dns_dbversion_t **targetp)
 400 {
 401         /*
 402          * Attach '*targetp' to 'source'.
 403          */
 404
 405         REQUIRE(DNS_DB_VALID(db));
 406         REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
 407         REQUIRE(source != NULL);
 408         REQUIRE(targetp != NULL && *targetp == NULL);
 409
 410         (db->methods->attachversion)(db, source, targetp);
 411
 412         ENSURE(*targetp != NULL);
 413 }
 414
 415 void
 416 dns_db_closeversion(dns_db_t *db, dns_dbversion_t **versionp,
 417                     isc_boolean_t commit)
 418 {
 419
 420         /*
 421          * Close version '*versionp'.
 422          */
 423
 424         REQUIRE(DNS_DB_VALID(db));
 425         REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
 426         REQUIRE(versionp != NULL && *versionp != NULL);
 427
 428         (db->methods->closeversion)(db, versionp, commit);
 429
 430         ENSURE(*versionp == NULL);
 431 }
 432
 433 /***
 434  *** Node Methods
 435  ***/
 436
 437 isc_result_t
 438 dns_db_findnode(dns_db_t *db, dns_name_t *name,
 439                 isc_boolean_t create, dns_dbnode_t **nodep)
 440 {
 441
 442         /*
 443          * Find the node with name 'name'.
 444          */
 445
 446         REQUIRE(DNS_DB_VALID(db));
 447         REQUIRE(nodep != NULL && *nodep == NULL);
 448
 449         return ((db->methods->findnode)(db, name, create, nodep));
 450 }
 451
 452 isc_result_t
 453 dns_db_find(dns_db_t *db, dns_name_t *name, dns_dbversion_t *version,
 454             dns_rdatatype_t type, unsigned int options, isc_stdtime_t now,
 455             dns_dbnode_t **nodep, dns_name_t *foundname,
 456             dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset)
 457 {
 458
 459         /*
 460          * Find the best match for 'name' and 'type' in version 'version'
 461          * of 'db'.
 462          */
 463
 464         REQUIRE(DNS_DB_VALID(db));
 465         REQUIRE(type != dns_rdatatype_rrsig);
 466         REQUIRE(nodep == NULL || (nodep != NULL && *nodep == NULL));
 467         REQUIRE(dns_name_hasbuffer(foundname));
 468         REQUIRE(rdataset == NULL ||
 469                 (DNS_RDATASET_VALID(rdataset) &&
 470                  ! dns_rdataset_isassociated(rdataset)));
 471         REQUIRE(sigrdataset == NULL ||
 472                 (DNS_RDATASET_VALID(sigrdataset) &&
 473                  ! dns_rdataset_isassociated(sigrdataset)));
 474
 475         return ((db->methods->find)(db, name, version, type, options, now,
 476                                     nodep, foundname, rdataset, sigrdataset));
 477 }
 478
 479 isc_result_t
 480 dns_db_findzonecut(dns_db_t *db, dns_name_t *name,
 481                    unsigned int options, isc_stdtime_t now,
 482                    dns_dbnode_t **nodep, dns_name_t *foundname,
 483                    dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset)
 484 {
 485         /*
 486          * Find the deepest known zonecut which encloses 'name' in 'db'.
 487          */
 488
 489         REQUIRE(DNS_DB_VALID(db));
 490         REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);
 491         REQUIRE(nodep == NULL || (nodep != NULL && *nodep == NULL));
 492         REQUIRE(dns_name_hasbuffer(foundname));
 493         REQUIRE(sigrdataset == NULL ||
 494                 (DNS_RDATASET_VALID(sigrdataset) &&
 495                  ! dns_rdataset_isassociated(sigrdataset)));
 496
 497         return ((db->methods->findzonecut)(db, name, options, now, nodep,
 498                                            foundname, rdataset, sigrdataset));
 499 }
 500
 501 void
 502 dns_db_attachnode(dns_db_t *db, dns_dbnode_t *source, dns_dbnode_t **targetp) {
 503
 504         /*
 505          * Attach *targetp to source.
 506          */
 507
 508         REQUIRE(DNS_DB_VALID(db));
 509         REQUIRE(source != NULL);
 510         REQUIRE(targetp != NULL && *targetp == NULL);
 511
 512         (db->methods->attachnode)(db, source, targetp);
 513 }
 514
 515 void
 516 dns_db_detachnode(dns_db_t *db, dns_dbnode_t **nodep) {
 517
 518         /*
 519          * Detach *nodep from its node.
 520          */
 521
 522         REQUIRE(DNS_DB_VALID(db));
 523         REQUIRE(nodep != NULL && *nodep != NULL);
 524
 525         (db->methods->detachnode)(db, nodep);
 526
 527         ENSURE(*nodep == NULL);
 528 }
 529
 530 isc_result_t
 531 dns_db_expirenode(dns_db_t *db, dns_dbnode_t *node, isc_stdtime_t now) {
 532
 533         /*
 534          * Mark as stale all records at 'node' which expire at or before 'now'.
 535          */
 536
 537         REQUIRE(DNS_DB_VALID(db));
 538         REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);
 539         REQUIRE(node != NULL);
 540
 541         return ((db->methods->expirenode)(db, node, now));
 542 }
 543
 544 void
 545 dns_db_printnode(dns_db_t *db, dns_dbnode_t *node, FILE *out) {
 546         /*
 547          * Print a textual representation of the contents of the node to
 548          * 'out'.
 549          */
 550
 551         REQUIRE(DNS_DB_VALID(db));
 552         REQUIRE(node != NULL);
 553
 554         (db->methods->printnode)(db, node, out);
 555 }
 556
 557 /***
 558  *** DB Iterator Creation
 559  ***/
 560
 561 isc_result_t
 562 dns_db_createiterator(dns_db_t *db, isc_boolean_t relative_names,
 563                       dns_dbiterator_t **iteratorp)
 564 {
 565         /*
 566          * Create an iterator for version 'version' of 'db'.
 567          */
 568
 569         REQUIRE(DNS_DB_VALID(db));
 570         REQUIRE(iteratorp != NULL && *iteratorp == NULL);
 571
 572         return (db->methods->createiterator(db, relative_names, iteratorp));
 573 }
 574
 575 /***
 576  *** Rdataset Methods
 577  ***/
 578
 579 isc_result_t
 580 dns_db_findrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
 581                     dns_rdatatype_t type, dns_rdatatype_t covers,
 582                     isc_stdtime_t now, dns_rdataset_t *rdataset,
 583                     dns_rdataset_t *sigrdataset)
 584 {
 585         /*
 586          * Search for an rdataset of type 'type' at 'node' that are in version
 587          * 'version' of 'db'.  If found, make 'rdataset' refer to it.
 588          */
 589
 590         REQUIRE(DNS_DB_VALID(db));
 591         REQUIRE(node != NULL);
 592         REQUIRE(DNS_RDATASET_VALID(rdataset));
 593         REQUIRE(! dns_rdataset_isassociated(rdataset));
 594         REQUIRE(covers == 0 || type == dns_rdatatype_rrsig);
 595         REQUIRE(type != dns_rdatatype_any);
 596         REQUIRE(sigrdataset == NULL ||
 597                 (DNS_RDATASET_VALID(sigrdataset) &&
 598                  ! dns_rdataset_isassociated(sigrdataset)));
 599
 600         return ((db->methods->findrdataset)(db, node, version, type, covers,
 601                                             now, rdataset, sigrdataset));
 602 }
 603
 604 isc_result_t
 605 dns_db_allrdatasets(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
 606                     isc_stdtime_t now, dns_rdatasetiter_t **iteratorp)
 607 {
 608         /*
 609          * Make '*iteratorp' an rdataset iteratator for all rdatasets at
 610          * 'node' in version 'version' of 'db'.
 611          */
 612
 613         REQUIRE(DNS_DB_VALID(db));
 614         REQUIRE(iteratorp != NULL && *iteratorp == NULL);
 615
 616         return ((db->methods->allrdatasets)(db, node, version, now,
 617                                             iteratorp));
 618 }
 619
 620 isc_result_t
 621 dns_db_addrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
 622                    isc_stdtime_t now, dns_rdataset_t *rdataset,
 623                    unsigned int options, dns_rdataset_t *addedrdataset)
 624 {
 625         /*
 626          * Add 'rdataset' to 'node' in version 'version' of 'db'.
 627          */
 628
 629         REQUIRE(DNS_DB_VALID(db));
 630         REQUIRE(node != NULL);
 631         REQUIRE(((db->attributes & DNS_DBATTR_CACHE) == 0 && version != NULL)||
 632                 ((db->attributes & DNS_DBATTR_CACHE) != 0 &&
 633                  version == NULL && (options & DNS_DBADD_MERGE) == 0));
 634         REQUIRE((options & DNS_DBADD_EXACT) == 0 ||
 635                 (options & DNS_DBADD_MERGE) != 0);
 636         REQUIRE(DNS_RDATASET_VALID(rdataset));
 637         REQUIRE(dns_rdataset_isassociated(rdataset));
 638         REQUIRE(rdataset->rdclass == db->rdclass);
 639         REQUIRE(addedrdataset == NULL ||
 640                 (DNS_RDATASET_VALID(addedrdataset) &&
 641                  ! dns_rdataset_isassociated(addedrdataset)));
 642
 643         return ((db->methods->addrdataset)(db, node, version, now, rdataset,
 644                                            options, addedrdataset));
 645 }
 646
 647 isc_result_t
 648 dns_db_subtractrdataset(dns_db_t *db, dns_dbnode_t *node,
 649                         dns_dbversion_t *version, dns_rdataset_t *rdataset,
 650                         unsigned int options, dns_rdataset_t *newrdataset)
 651 {
 652         /*
 653          * Remove any rdata in 'rdataset' from 'node' in version 'version' of
 654          * 'db'.
 655          */
 656
 657         REQUIRE(DNS_DB_VALID(db));
 658         REQUIRE(node != NULL);
 659         REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0 && version != NULL);
 660         REQUIRE(DNS_RDATASET_VALID(rdataset));
 661         REQUIRE(dns_rdataset_isassociated(rdataset));
 662         REQUIRE(rdataset->rdclass == db->rdclass);
 663         REQUIRE(newrdataset == NULL ||
 664                 (DNS_RDATASET_VALID(newrdataset) &&
 665                  ! dns_rdataset_isassociated(newrdataset)));
 666
 667         return ((db->methods->subtractrdataset)(db, node, version, rdataset,
 668                                                 options, newrdataset));
 669 }
 670
 671 isc_result_t
 672 dns_db_deleterdataset(dns_db_t *db, dns_dbnode_t *node,
 673                       dns_dbversion_t *version, dns_rdatatype_t type,
 674                       dns_rdatatype_t covers)
 675 {
 676         /*
 677          * Make it so that no rdataset of type 'type' exists at 'node' in
 678          * version version 'version' of 'db'.
 679          */
 680
 681         REQUIRE(DNS_DB_VALID(db));
 682         REQUIRE(node != NULL);
 683         REQUIRE(((db->attributes & DNS_DBATTR_CACHE) == 0 && version != NULL)||
 684                 ((db->attributes & DNS_DBATTR_CACHE) != 0 && version == NULL));
 685
 686         return ((db->methods->deleterdataset)(db, node, version,
 687                                               type, covers));
 688 }
 689
 690 void
 691 dns_db_overmem(dns_db_t *db, isc_boolean_t overmem) {
 692
 693         REQUIRE(DNS_DB_VALID(db));
 694
 695         (db->methods->overmem)(db, overmem);
 696 }
 697
 698 isc_result_t
 699 dns_db_getsoaserial(dns_db_t *db, dns_dbversion_t *ver, isc_uint32_t *serialp)
 700 {
 701         isc_result_t result;
 702         dns_dbnode_t *node = NULL;
 703         dns_rdataset_t rdataset;
 704         dns_rdata_t rdata = DNS_RDATA_INIT;
 705         isc_buffer_t buffer;
 706
 707         REQUIRE(dns_db_iszone(db) || dns_db_isstub(db));
 708
 709         result = dns_db_findnode(db, dns_db_origin(db), ISC_FALSE, &node);
 710         if (result != ISC_R_SUCCESS)
 711                 return (result);
 712
 713         dns_rdataset_init(&rdataset);
 714         result = dns_db_findrdataset(db, node, ver, dns_rdatatype_soa, 0,
 715                                      (isc_stdtime_t)0, &rdataset, NULL);
 716         if (result != ISC_R_SUCCESS)
 717                 goto freenode;
 718
 719         result = dns_rdataset_first(&rdataset);
 720         if (result != ISC_R_SUCCESS)
 721                 goto freerdataset;
 722         dns_rdataset_current(&rdataset, &rdata);
 723         result = dns_rdataset_next(&rdataset);
 724         INSIST(result == ISC_R_NOMORE);
 725
 726         INSIST(rdata.length > 20);
 727         isc_buffer_init(&buffer, rdata.data, rdata.length);
 728         isc_buffer_add(&buffer, rdata.length);
 729         isc_buffer_forward(&buffer, rdata.length - 20);
 730         *serialp = isc_buffer_getuint32(&buffer);
 731
 732         result = ISC_R_SUCCESS;
 733
 734  freerdataset:
 735         dns_rdataset_disassociate(&rdataset);
 736
 737  freenode:
 738         dns_db_detachnode(db, &node);
 739         return (result);
 740 }
 741
 742 unsigned int
 743 dns_db_nodecount(dns_db_t *db) {
 744         REQUIRE(DNS_DB_VALID(db));
 745
 746         return ((db->methods->nodecount)(db));
 747 }
 748
 749 void
 750 dns_db_settask(dns_db_t *db, isc_task_t *task) {
 751         REQUIRE(DNS_DB_VALID(db));
 752
 753         (db->methods->settask)(db, task);
 754 }
 755
 756 isc_result_t
 757 dns_db_register(const char *name, dns_dbcreatefunc_t create, void *driverarg,
 758                 isc_mem_t *mctx, dns_dbimplementation_t **dbimp)
 759 {
 760         dns_dbimplementation_t *imp;
 761
 762         REQUIRE(name != NULL);
 763         REQUIRE(dbimp != NULL && *dbimp == NULL);
 764
 765         RUNTIME_CHECK(isc_once_do(&once, initialize) == ISC_R_SUCCESS);
 766
 767         RWLOCK(&implock, isc_rwlocktype_write);
 768         imp = impfind(name);
 769         if (imp != NULL) {
 770                 RWUNLOCK(&implock, isc_rwlocktype_write);
 771                 return (ISC_R_EXISTS);
 772         }
 773
 774         imp = isc_mem_get(mctx, sizeof(dns_dbimplementation_t));
 775         if (imp == NULL) {
 776                 RWUNLOCK(&implock, isc_rwlocktype_write);
 777                 return (ISC_R_NOMEMORY);
 778         }
 779         imp->name = name;
 780         imp->create = create;
 781         imp->mctx = NULL;
 782         imp->driverarg = driverarg;
 783         isc_mem_attach(mctx, &imp->mctx);
 784         ISC_LINK_INIT(imp, link);
 785         ISC_LIST_APPEND(implementations, imp, link);
 786         RWUNLOCK(&implock, isc_rwlocktype_write);
 787
 788         *dbimp = imp;
 789
 790         return (ISC_R_SUCCESS);
 791 }
 792
 793 void
 794 dns_db_unregister(dns_dbimplementation_t **dbimp) {
 795         dns_dbimplementation_t *imp;
 796         isc_mem_t *mctx;
 797
 798         REQUIRE(dbimp != NULL && *dbimp != NULL);
 799
 800         RUNTIME_CHECK(isc_once_do(&once, initialize) == ISC_R_SUCCESS);
 801
 802         imp = *dbimp;
 803         RWLOCK(&implock, isc_rwlocktype_write);
 804         ISC_LIST_UNLINK(implementations, imp, link);
 805         mctx = imp->mctx;
 806         isc_mem_put(mctx, imp, sizeof(dns_dbimplementation_t));
 807         isc_mem_detach(&mctx);
 808         RWUNLOCK(&implock, isc_rwlocktype_write);
 809 }
 810
 811 isc_result_t
 812 dns_db_getoriginnode(dns_db_t *db, dns_dbnode_t **nodep) {
 813         REQUIRE(DNS_DB_VALID(db));
 814         REQUIRE(dns_db_iszone(db) == ISC_TRUE);
 815         REQUIRE(nodep != NULL && *nodep == NULL);
 816
 817         if (db->methods->getoriginnode != NULL)
 818                 return ((db->methods->getoriginnode)(db, nodep));
 819
 820         return (ISC_R_NOTFOUND);
 821 }