source4/dns_server/dns_update.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    DNS server handler for update requests
   5
   6    Copyright (C) 2010 Kai Blin  <kai@samba.org>
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "libcli/util/ntstatus.h"
  24 #include "librpc/ndr/libndr.h"
  25 #include "librpc/gen_ndr/ndr_dns.h"
  26 #include "librpc/gen_ndr/ndr_dnsp.h"
  27 #include <ldb.h>
  28 #include "param/param.h"
  29 #include "dsdb/samdb/samdb.h"
  30 #include "dsdb/common/util.h"
  31 #include "smbd/service_task.h"
  32 #include "dns_server/dns_server.h"
  33 #include "dns_server/dns_update.h"
  34
  35 static WERROR dns_rr_to_dnsp(TALLOC_CTX *mem_ctx,
  36                              const struct dns_res_rec *rrec,
  37                              struct dnsp_DnssrvRpcRecord *r);
  38
  39 static WERROR check_one_prerequisite(struct dns_server *dns,
  40                                      TALLOC_CTX *mem_ctx,
  41                                      const struct dns_name_question *zone,
  42                                      const struct dns_res_rec *pr,
  43                                      bool *final_result)
  44 {
  45         bool match;
  46         WERROR werror;
  47         struct ldb_dn *dn;
  48         uint16_t i;
  49         bool found = false;
  50         struct dnsp_DnssrvRpcRecord *rec = NULL;
  51         struct dnsp_DnssrvRpcRecord *ans;
  52         uint16_t acount;
  53
  54         size_t host_part_len = 0;
  55
  56         *final_result = true;
  57
  58         if (pr->ttl != 0) {
  59                 return DNS_ERR(FORMAT_ERROR);
  60         }
  61
  62         match = dns_name_match(zone->name, pr->name, &host_part_len);
  63         if (!match) {
  64                 return DNS_ERR(NOTZONE);
  65         }
  66
  67         werror = dns_name2dn(dns, mem_ctx, pr->name, &dn);
  68         W_ERROR_NOT_OK_RETURN(werror);
  69
  70         if (pr->rr_class == DNS_QCLASS_ANY) {
  71
  72                 if (pr->length != 0) {
  73                         return DNS_ERR(FORMAT_ERROR);
  74                 }
  75
  76
  77                 if (pr->rr_type == DNS_QTYPE_ALL) {
  78                         /*
  79                          */
  80                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
  81                         W_ERROR_NOT_OK_RETURN(werror);
  82
  83                         if (acount == 0) {
  84                                 return DNS_ERR(NAME_ERROR);
  85                         }
  86                 } else {
  87                         /*
  88                          */
  89                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
  90                         if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
  91                                 return DNS_ERR(NXRRSET);
  92                         }
  93                         W_ERROR_NOT_OK_RETURN(werror);
  94
  95                         for (i = 0; i < acount; i++) {
  96                                 if (ans[i].wType == pr->rr_type) {
  97                                         found = true;
  98                                         break;
  99                                 }
 100                         }
 101                         if (!found) {
 102                                 return DNS_ERR(NXRRSET);
 103                         }
 104                 }
 105
 106                 /*
 107                  * RFC2136 3.2.5 doesn't actually mention the need to return
 108                  * OK here, but otherwise we'd always return a FORMAT_ERROR
 109                  * later on. This also matches Microsoft DNS behavior.
 110                  */
 111                 return WERR_OK;
 112         }
 113
 114         if (pr->rr_class == DNS_QCLASS_NONE) {
 115                 if (pr->length != 0) {
 116                         return DNS_ERR(FORMAT_ERROR);
 117                 }
 118
 119                 if (pr->rr_type == DNS_QTYPE_ALL) {
 120                         /*
 121                          */
 122                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
 123                         if (W_ERROR_EQUAL(werror, WERR_OK)) {
 124                                 return DNS_ERR(YXDOMAIN);
 125                         }
 126                 } else {
 127                         /*
 128                          */
 129                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
 130                         if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 131                                 werror = WERR_OK;
 132                                 ans = NULL;
 133                                 acount = 0;
 134                         }
 135
 136                         for (i = 0; i < acount; i++) {
 137                                 if (ans[i].wType == pr->rr_type) {
 138                                         found = true;
 139                                         break;
 140                                 }
 141                         }
 142                         if (found) {
 143                                 return DNS_ERR(YXRRSET);
 144                         }
 145                 }
 146
 147                 /*
 148                  * RFC2136 3.2.5 doesn't actually mention the need to return
 149                  * OK here, but otherwise we'd always return a FORMAT_ERROR
 150                  * later on. This also matches Microsoft DNS behavior.
 151                  */
 152                 return WERR_OK;
 153         }
 154
 155         if (pr->rr_class != zone->question_class) {
 156                 return DNS_ERR(FORMAT_ERROR);
 157         }
 158
 159         *final_result = false;
 160
 161         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
 162         if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 163                 return DNS_ERR(NXRRSET);
 164         }
 165         W_ERROR_NOT_OK_RETURN(werror);
 166
 167         rec = talloc_zero(mem_ctx, struct dnsp_DnssrvRpcRecord);
 168         W_ERROR_HAVE_NO_MEMORY(rec);
 169
 170         werror = dns_rr_to_dnsp(rec, pr, rec);
 171         W_ERROR_NOT_OK_RETURN(werror);
 172
 173         for (i = 0; i < acount; i++) {
 174                 if (dns_records_match(rec, &ans[i])) {
 175                         found = true;
 176                         break;
 177                 }
 178         }
 179
 180         if (!found) {
 181                 return DNS_ERR(NXRRSET);
 182         }
 183
 184         return WERR_OK;
 185 }
 186
 187 static WERROR check_prerequisites(struct dns_server *dns,
 188                                   TALLOC_CTX *mem_ctx,
 189                                   const struct dns_name_question *zone,
 190                                   const struct dns_res_rec *prereqs, uint16_t count)
 191 {
 192         uint16_t i;
 193         WERROR final_error = WERR_OK;
 194
 195         for (i = 0; i < count; i++) {
 196                 bool final;
 197                 WERROR werror;
 198
 199                 werror = check_one_prerequisite(dns, mem_ctx, zone,
 200                                                 &prereqs[i], &final);
 201                 if (!W_ERROR_IS_OK(werror)) {
 202                         if (final) {
 203                                 return werror;
 204                         }
 205                         if (W_ERROR_IS_OK(final_error)) {
 206                                 final_error = werror;
 207                         }
 208                 }
 209         }
 210
 211         if (!W_ERROR_IS_OK(final_error)) {
 212                 return final_error;
 213         }
 214
 215         return WERR_OK;
 216 }
 217
 218 static WERROR update_prescan(const struct dns_name_question *zone,
 219                              const struct dns_res_rec *updates, uint16_t count)
 220 {
 221         const struct dns_res_rec *r;
 222         uint16_t i;
 223         size_t host_part_len;
 224         bool match;
 225
 226         for (i = 0; i < count; i++) {
 227                 r = &updates[i];
 228                 match = dns_name_match(zone->name, r->name, &host_part_len);
 229                 if (!match) {
 230                         return DNS_ERR(NOTZONE);
 231                 }
 232                 if (zone->question_class == r->rr_class) {
 233                         if (r->rr_type == DNS_QTYPE_ALL) {
 234                                 return DNS_ERR(FORMAT_ERROR);
 235                         }
 236                         if (r->rr_type == DNS_QTYPE_AXFR) {
 237                                 return DNS_ERR(FORMAT_ERROR);
 238                         }
 239                         if (r->rr_type == DNS_QTYPE_MAILB) {
 240                                 return DNS_ERR(FORMAT_ERROR);
 241                         }
 242                         if (r->rr_type == DNS_QTYPE_MAILA) {
 243                                 return DNS_ERR(FORMAT_ERROR);
 244                         }
 245                 } else if (r->rr_class == DNS_QCLASS_ANY) {
 246                         if (r->ttl != 0) {
 247                                 return DNS_ERR(FORMAT_ERROR);
 248                         }
 249                         if (r->length != 0) {
 250                                 return DNS_ERR(FORMAT_ERROR);
 251                         }
 252                         if (r->rr_type == DNS_QTYPE_AXFR) {
 253                                 return DNS_ERR(FORMAT_ERROR);
 254                         }
 255                         if (r->rr_type == DNS_QTYPE_MAILB) {
 256                                 return DNS_ERR(FORMAT_ERROR);
 257                         }
 258                         if (r->rr_type == DNS_QTYPE_MAILA) {
 259                                 return DNS_ERR(FORMAT_ERROR);
 260                         }
 261                 } else if (r->rr_class == DNS_QCLASS_NONE) {
 262                         if (r->ttl != 0) {
 263                                 return DNS_ERR(FORMAT_ERROR);
 264                         }
 265                         if (r->rr_type == DNS_QTYPE_ALL) {
 266                                 return DNS_ERR(FORMAT_ERROR);
 267                         }
 268                         if (r->rr_type == DNS_QTYPE_AXFR) {
 269                                 return DNS_ERR(FORMAT_ERROR);
 270                         }
 271                         if (r->rr_type == DNS_QTYPE_MAILB) {
 272                                 return DNS_ERR(FORMAT_ERROR);
 273                         }
 274                         if (r->rr_type == DNS_QTYPE_MAILA) {
 275                                 return DNS_ERR(FORMAT_ERROR);
 276                         }
 277                 } else {
 278                         return DNS_ERR(FORMAT_ERROR);
 279                 }
 280         }
 281         return WERR_OK;
 282 }
 283
 284 static WERROR dns_rr_to_dnsp(TALLOC_CTX *mem_ctx,
 285                              const struct dns_res_rec *rrec,
 286                              struct dnsp_DnssrvRpcRecord *r)
 287 {
 288         if (rrec->rr_type == DNS_QTYPE_ALL) {
 289                 return DNS_ERR(FORMAT_ERROR);
 290         }
 291
 292         ZERO_STRUCTP(r);
 293
 294         r->wType = rrec->rr_type;
 295         r->dwTtlSeconds = rrec->ttl;
 296         r->rank = DNS_RANK_ZONE;
 297         /* TODO: Autogenerate this somehow */
 298         r->dwSerial = 110;
 299
 300         /* If we get QCLASS_ANY, we're done here */
 301         if (rrec->rr_class == DNS_QCLASS_ANY) {
 302                 goto done;
 303         }
 304
 305         switch(rrec->rr_type) {
 306         case DNS_QTYPE_A:
 307                 r->data.ipv4 = talloc_strdup(mem_ctx, rrec->rdata.ipv4_record);
 308                 W_ERROR_HAVE_NO_MEMORY(r->data.ipv4);
 309                 break;
 310         case DNS_QTYPE_AAAA:
 311                 r->data.ipv6 = talloc_strdup(mem_ctx, rrec->rdata.ipv6_record);
 312                 W_ERROR_HAVE_NO_MEMORY(r->data.ipv6);
 313                 break;
 314         case DNS_QTYPE_NS:
 315                 r->data.ns = talloc_strdup(mem_ctx, rrec->rdata.ns_record);
 316                 W_ERROR_HAVE_NO_MEMORY(r->data.ns);
 317                 break;
 318         case DNS_QTYPE_CNAME:
 319                 r->data.cname = talloc_strdup(mem_ctx, rrec->rdata.cname_record);
 320                 W_ERROR_HAVE_NO_MEMORY(r->data.cname);
 321                 break;
 322         case DNS_QTYPE_SRV:
 323                 r->data.srv.wPriority = rrec->rdata.srv_record.priority;
 324                 r->data.srv.wWeight = rrec->rdata.srv_record.weight;
 325                 r->data.srv.wPort = rrec->rdata.srv_record.port;
 326                 r->data.srv.nameTarget = talloc_strdup(mem_ctx,
 327                                 rrec->rdata.srv_record.target);
 328                 W_ERROR_HAVE_NO_MEMORY(r->data.srv.nameTarget);
 329                 break;
 330         case DNS_QTYPE_MX:
 331                 r->data.mx.wPriority = rrec->rdata.mx_record.preference;
 332                 r->data.mx.nameTarget = talloc_strdup(mem_ctx,
 333                                 rrec->rdata.mx_record.exchange);
 334                 W_ERROR_HAVE_NO_MEMORY(r->data.mx.nameTarget);
 335                 break;
 336         case DNS_QTYPE_TXT:
 337                 r->data.txt = talloc_strdup(mem_ctx, rrec->rdata.txt_record.txt);
 338                 W_ERROR_HAVE_NO_MEMORY(r->data.txt);
 339                 break;
 340         default:
 341                 DEBUG(0, ("Got a qytpe of %d\n", rrec->rr_type));
 342                 return DNS_ERR(NOT_IMPLEMENTED);
 343         }
 344
 345 done:
 346
 347         return WERR_OK;
 348 }
 349
 350
 351 static WERROR handle_one_update(struct dns_server *dns,
 352                                 TALLOC_CTX *mem_ctx,
 353                                 const struct dns_name_question *zone,
 354                                 const struct dns_res_rec *update)
 355 {
 356         struct dnsp_DnssrvRpcRecord *recs = NULL;
 357         uint16_t rcount = 0;
 358         struct ldb_dn *dn;
 359         uint16_t i;
 360         WERROR werror;
 361         bool needs_add = false;
 362
 363         DEBUG(1, ("Looking at record: \n"));
 364         NDR_PRINT_DEBUG(dns_res_rec, discard_const(update));
 365
 366         switch (update->rr_type) {
 367         case DNS_QTYPE_A:
 368                 break;
 369         case DNS_QTYPE_NS:
 370                 break;
 371         case DNS_QTYPE_CNAME:
 372                 break;
 373         case DNS_QTYPE_SOA:
 374                 break;
 375         case DNS_QTYPE_PTR:
 376                 break;
 377         case DNS_QTYPE_MX:
 378                 break;
 379         case DNS_QTYPE_AAAA:
 380                 break;
 381         case DNS_QTYPE_SRV:
 382                 break;
 383         case DNS_QTYPE_TXT:
 384                 break;
 385         default:
 386                 return DNS_ERR(NOT_IMPLEMENTED);
 387         }
 388
 389         werror = dns_name2dn(dns, mem_ctx, update->name, &dn);
 390         W_ERROR_NOT_OK_RETURN(werror);
 391
 392         werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rcount);
 393         if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 394                 recs = NULL;
 395                 rcount = 0;
 396                 needs_add = true;
 397                 werror = WERR_OK;
 398         }
 399         W_ERROR_NOT_OK_RETURN(werror);
 400
 401         if (update->rr_class == zone->question_class) {
 402                 if (update->rr_type == DNS_QTYPE_CNAME) {
 403                         /*
 404                          * If there is a record in the directory
 405                          * that's not a CNAME, ignore update
 406                          */
 407                         for (i = 0; i < rcount; i++) {
 408                                 if (recs[i].wType != DNS_TYPE_CNAME) {
 409                                         DEBUG(0, ("Skipping update\n"));
 410                                         return WERR_OK;
 411                                 }
 412                                 break;
 413                         }
 414
 415                         /*
 416                          * There should be no entries besides one CNAME record
 417                          * per name, so replace everything with the new CNAME
 418                          */
 419
 420                         rcount = 1;
 421                         recs = talloc_realloc(mem_ctx, recs,
 422                                         struct dnsp_DnssrvRpcRecord, rcount);
 423                         W_ERROR_HAVE_NO_MEMORY(recs);
 424
 425                         werror = dns_rr_to_dnsp(recs, update, &recs[0]);
 426                         W_ERROR_NOT_OK_RETURN(werror);
 427
 428                         werror = dns_replace_records(dns, mem_ctx, dn,
 429                                                      needs_add, recs, rcount);
 430                         W_ERROR_NOT_OK_RETURN(werror);
 431
 432                         return WERR_OK;
 433                 } else {
 434                         /*
 435                          * If there is a CNAME record for this name,
 436                          * ignore update
 437                          */
 438                         for (i = 0; i < rcount; i++) {
 439                                 if (recs[i].wType == DNS_TYPE_CNAME) {
 440                                         DEBUG(0, ("Skipping update\n"));
 441                                         return WERR_OK;
 442                                 }
 443                         }
 444                 }
 445                 if (update->rr_type == DNS_QTYPE_SOA) {
 446                         bool found = false;
 447
 448                         /*
 449                          * If the zone has no SOA record?? or update's
 450                          * serial number is smaller than existing SOA's,
 451                          * ignore update
 452                          */
 453                         for (i = 0; i < rcount; i++) {
 454                                 if (recs[i].wType == DNS_TYPE_SOA) {
 455                                         uint16_t n, o;
 456
 457                                         n = update->rdata.soa_record.serial;
 458                                         o = recs[i].data.soa.serial;
 459                                         /*
 460                                          * TODO: Implement RFC 1982 comparison
 461                                          * logic for RFC2136
 462                                          */
 463                                         if (n <= o) {
 464                                                 DEBUG(0, ("Skipping update\n"));
 465                                                 return WERR_OK;
 466                                         }
 467                                         found = true;
 468                                         break;
 469                                 }
 470                         }
 471                         if (!found) {
 472                                 DEBUG(0, ("Skipping update\n"));
 473                                 return WERR_OK;
 474                         }
 475
 476                         werror = dns_rr_to_dnsp(mem_ctx, update, &recs[i]);
 477                         W_ERROR_NOT_OK_RETURN(werror);
 478
 479                         for (i++; i < rcount; i++) {
 480                                 if (recs[i].wType != DNS_TYPE_SOA) {
 481                                         continue;
 482                                 }
 483
 484                                 ZERO_STRUCT(recs[i]);
 485                         }
 486
 487                         werror = dns_replace_records(dns, mem_ctx, dn,
 488                                                      needs_add, recs, rcount);
 489                         W_ERROR_NOT_OK_RETURN(werror);
 490
 491                         return WERR_OK;
 492                 }
 493
 494                 recs = talloc_realloc(mem_ctx, recs,
 495                                 struct dnsp_DnssrvRpcRecord, rcount+1);
 496                 W_ERROR_HAVE_NO_MEMORY(recs);
 497
 498                 werror = dns_rr_to_dnsp(recs, update, &recs[rcount]);
 499                 W_ERROR_NOT_OK_RETURN(werror);
 500
 501                 for (i = 0; i < rcount; i++) {
 502                         if (!dns_records_match(&recs[i], &recs[rcount])) {
 503                                 continue;
 504                         }
 505
 506                         recs[i] = recs[rcount];
 507
 508                         werror = dns_replace_records(dns, mem_ctx, dn,
 509                                                      needs_add, recs, rcount);
 510                         W_ERROR_NOT_OK_RETURN(werror);
 511
 512                         return WERR_OK;
 513                 }
 514
 515                 werror = dns_replace_records(dns, mem_ctx, dn,
 516                                              needs_add, recs, rcount+1);
 517                 W_ERROR_NOT_OK_RETURN(werror);
 518
 519                 return WERR_OK;
 520         } else if (update->rr_class == DNS_QCLASS_ANY) {
 521                 if (update->rr_type == DNS_QTYPE_ALL) {
 522                         if (dns_name_equal(update->name, zone->name)) {
 523                                 for (i = 0; i < rcount; i++) {
 524
 525                                         if (recs[i].wType == DNS_TYPE_SOA) {
 526                                                 continue;
 527                                         }
 528
 529                                         if (recs[i].wType == DNS_TYPE_NS) {
 530                                                 continue;
 531                                         }
 532
 533                                         ZERO_STRUCT(recs[i]);
 534                                 }
 535
 536                         } else {
 537                                 for (i = 0; i < rcount; i++) {
 538                                         ZERO_STRUCT(recs[i]);
 539                                 }
 540                         }
 541
 542                 } else if (dns_name_equal(update->name, zone->name)) {
 543
 544                         if (update->rr_type == DNS_QTYPE_SOA) {
 545                                 return WERR_OK;
 546                         }
 547
 548                         if (update->rr_type == DNS_QTYPE_NS) {
 549                                 return WERR_OK;
 550                         }
 551                 }
 552                 for (i = 0; i < rcount; i++) {
 553                         if (recs[i].wType == update->rr_type) {
 554                                 ZERO_STRUCT(recs[i]);
 555                         }
 556                 }
 557
 558                 werror = dns_replace_records(dns, mem_ctx, dn,
 559                                              needs_add, recs, rcount);
 560                 W_ERROR_NOT_OK_RETURN(werror);
 561
 562                 return WERR_OK;
 563         } else if (update->rr_class == DNS_QCLASS_NONE) {
 564                 struct dnsp_DnssrvRpcRecord *del_rec;
 565
 566                 if (update->rr_type == DNS_QTYPE_SOA) {
 567                         return WERR_OK;
 568                 }
 569                 if (update->rr_type == DNS_QTYPE_NS) {
 570                         bool found = false;
 571                         struct dnsp_DnssrvRpcRecord *ns_rec = talloc(mem_ctx,
 572                                                 struct dnsp_DnssrvRpcRecord);
 573                         W_ERROR_HAVE_NO_MEMORY(ns_rec);
 574
 575
 576                         werror = dns_rr_to_dnsp(ns_rec, update, ns_rec);
 577                         W_ERROR_NOT_OK_RETURN(werror);
 578
 579                         for (i = 0; i < rcount; i++) {
 580                                 if (dns_records_match(ns_rec, &recs[i])) {
 581                                         found = true;
 582                                         break;
 583                                 }
 584                         }
 585                         if (found) {
 586                                 return WERR_OK;
 587                         }
 588                 }
 589
 590                 del_rec = talloc(mem_ctx, struct dnsp_DnssrvRpcRecord);
 591                 W_ERROR_HAVE_NO_MEMORY(del_rec);
 592
 593                 werror = dns_rr_to_dnsp(del_rec, update, del_rec);
 594                 W_ERROR_NOT_OK_RETURN(werror);
 595
 596                 for (i = 0; i < rcount; i++) {
 597                         if (dns_records_match(del_rec, &recs[i])) {
 598                                 ZERO_STRUCT(recs[i]);
 599                         }
 600                 }
 601         }
 602
 603         return WERR_OK;
 604 }
 605
 606 static WERROR handle_updates(struct dns_server *dns,
 607                              TALLOC_CTX *mem_ctx,
 608                              const struct dns_name_question *zone,
 609                              const struct dns_res_rec *prereqs, uint16_t pcount,
 610                              struct dns_res_rec *updates, uint16_t upd_count)
 611 {
 612         struct ldb_dn *zone_dn = NULL;
 613         WERROR werror = WERR_OK;
 614         int ret;
 615         uint16_t ri;
 616         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 617
 618         werror = dns_name2dn(dns, tmp_ctx, zone->name, &zone_dn);
 619         W_ERROR_NOT_OK_RETURN(werror);
 620
 621         ret = ldb_transaction_start(dns->samdb);
 622         if (ret != LDB_SUCCESS) {
 623                 return DNS_ERR(SERVER_FAILURE);
 624         }
 625
 626         werror = check_prerequisites(dns, tmp_ctx, zone, prereqs, pcount);
 627         W_ERROR_NOT_OK_GOTO(werror, failed);
 628
 629         DEBUG(0, ("update count is %u\n", upd_count));
 630
 631         for (ri = 0; ri < upd_count; ri++) {
 632                 werror = handle_one_update(dns, tmp_ctx, zone,
 633                                            &updates[ri]);
 634                 W_ERROR_NOT_OK_GOTO(werror, failed);
 635         }
 636
 637         ldb_transaction_commit(dns->samdb);
 638         TALLOC_FREE(tmp_ctx);
 639         return WERR_OK;
 640
 641 failed:
 642         ldb_transaction_cancel(dns->samdb);
 643         TALLOC_FREE(tmp_ctx);
 644         return werror;
 645
 646 }
 647
 648 WERROR dns_server_process_update(struct dns_server *dns,
 649                                  TALLOC_CTX *mem_ctx,
 650                                  struct dns_name_packet *in,
 651                                  struct dns_res_rec **prereqs,    uint16_t *prereq_count,
 652                                  struct dns_res_rec **updates,    uint16_t *update_count,
 653                                  struct dns_res_rec **additional, uint16_t *arcount)
 654 {
 655         struct dns_name_question *zone;
 656         const struct dns_server_zone *z;
 657         size_t host_part_len = 0;
 658         WERROR werror = DNS_ERR(NOT_IMPLEMENTED);
 659
 660         if (in->qdcount != 1) {
 661                 return DNS_ERR(FORMAT_ERROR);
 662         }
 663
 664         zone = &in->questions[0];
 665
 666         if (zone->question_class != DNS_QCLASS_IN &&
 667             zone->question_class != DNS_QCLASS_ANY) {
 668                 return DNS_ERR(NOT_IMPLEMENTED);
 669         }
 670
 671         if (zone->question_type != DNS_QTYPE_SOA) {
 672                 return DNS_ERR(FORMAT_ERROR);
 673         }
 674
 675         DEBUG(0, ("Got a dns update request.\n"));
 676
 677         for (z = dns->zones; z != NULL; z = z->next) {
 678                 bool match;
 679
 680                 match = dns_name_match(z->name, zone->name, &host_part_len);
 681                 if (match) {
 682                         break;
 683                 }
 684         }
 685
 686         if (z == NULL) {
 687                 DEBUG(0, ("We're not authorative for this zone\n"));
 688                 return DNS_ERR(NOTAUTH);
 689         }
 690
 691         if (host_part_len != 0) {
 692                 /* TODO: We need to delegate this one */
 693                 DEBUG(0, ("Would have to delegate zones.\n"));
 694                 return DNS_ERR(NOT_IMPLEMENTED);
 695         }
 696
 697         *prereq_count = in->ancount;
 698         *prereqs = in->answers;
 699         werror = check_prerequisites(dns, mem_ctx, in->questions, *prereqs,
 700                                      *prereq_count);
 701         W_ERROR_NOT_OK_RETURN(werror);
 702
 703         /* TODO: Check if update is allowed, we probably want "always",
 704          * key-based GSSAPI, key-based bind-style TSIG and "never" as
 705          * smb.conf options. */
 706         if (lpcfg_allow_dns_updates(dns->task->lp_ctx) != DNS_UPDATE_ON) {
 707                 DEBUG(0, ("Update not allowed."));
 708                 return DNS_ERR(REFUSED);
 709         }
 710
 711         *update_count = in->nscount;
 712         *updates = in->nsrecs;
 713         werror = update_prescan(in->questions, *updates, *update_count);
 714         W_ERROR_NOT_OK_RETURN(werror);
 715
 716
 717         werror = handle_updates(dns, mem_ctx, in->questions, *prereqs,
 718                                 *prereq_count, *updates, *update_count);
 719         W_ERROR_NOT_OK_RETURN(werror);
 720
 721         return werror;
 722 }