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         char *tmp;
 289         char *txt_record_txt;
 290         char *saveptr = NULL;
 291
 292         if (rrec->rr_type == DNS_QTYPE_ALL) {
 293                 return DNS_ERR(FORMAT_ERROR);
 294         }
 295
 296         ZERO_STRUCTP(r);
 297
 298         r->wType = rrec->rr_type;
 299         r->dwTtlSeconds = rrec->ttl;
 300         r->rank = DNS_RANK_ZONE;
 301         /* TODO: Autogenerate this somehow */
 302         r->dwSerial = 110;
 303
 304         /* If we get QCLASS_ANY, we're done here */
 305         if (rrec->rr_class == DNS_QCLASS_ANY) {
 306                 goto done;
 307         }
 308
 309         switch(rrec->rr_type) {
 310         case DNS_QTYPE_A:
 311                 r->data.ipv4 = talloc_strdup(mem_ctx, rrec->rdata.ipv4_record);
 312                 W_ERROR_HAVE_NO_MEMORY(r->data.ipv4);
 313                 break;
 314         case DNS_QTYPE_AAAA:
 315                 r->data.ipv6 = talloc_strdup(mem_ctx, rrec->rdata.ipv6_record);
 316                 W_ERROR_HAVE_NO_MEMORY(r->data.ipv6);
 317                 break;
 318         case DNS_QTYPE_NS:
 319                 r->data.ns = talloc_strdup(mem_ctx, rrec->rdata.ns_record);
 320                 W_ERROR_HAVE_NO_MEMORY(r->data.ns);
 321                 break;
 322         case DNS_QTYPE_CNAME:
 323                 r->data.cname = talloc_strdup(mem_ctx, rrec->rdata.cname_record);
 324                 W_ERROR_HAVE_NO_MEMORY(r->data.cname);
 325                 break;
 326         case DNS_QTYPE_SRV:
 327                 r->data.srv.wPriority = rrec->rdata.srv_record.priority;
 328                 r->data.srv.wWeight = rrec->rdata.srv_record.weight;
 329                 r->data.srv.wPort = rrec->rdata.srv_record.port;
 330                 r->data.srv.nameTarget = talloc_strdup(mem_ctx,
 331                                 rrec->rdata.srv_record.target);
 332                 W_ERROR_HAVE_NO_MEMORY(r->data.srv.nameTarget);
 333                 break;
 334         case DNS_QTYPE_MX:
 335                 r->data.mx.wPriority = rrec->rdata.mx_record.preference;
 336                 r->data.mx.nameTarget = talloc_strdup(mem_ctx,
 337                                 rrec->rdata.mx_record.exchange);
 338                 W_ERROR_HAVE_NO_MEMORY(r->data.mx.nameTarget);
 339                 break;
 340         case DNS_QTYPE_TXT:
 341                 r->data.txt.count = 0;
 342                 r->data.txt.str = talloc_array(mem_ctx, const char *,
 343                                                r->data.txt.count);
 344                 W_ERROR_HAVE_NO_MEMORY(r->data.txt.str);
 345
 346                 txt_record_txt = talloc_strdup(r->data.txt.str,
 347                                                rrec->rdata.txt_record.txt);
 348                 W_ERROR_HAVE_NO_MEMORY(txt_record_txt);
 349
 350                 tmp = strtok_r(txt_record_txt, "\"", &saveptr);
 351                 while (tmp) {
 352                         if (strcmp(tmp, " ") == 0) {
 353                                 tmp = strtok_r(NULL, "\"", &saveptr);
 354                                 continue;
 355                         }
 356                         r->data.txt.str = talloc_realloc(mem_ctx, r->data.txt.str, const char *,
 357                                                         r->data.txt.count+1);
 358                         r->data.txt.str[r->data.txt.count] = talloc_strdup(r->data.txt.str, tmp);
 359                         W_ERROR_HAVE_NO_MEMORY(r->data.txt.str[r->data.txt.count]);
 360
 361                         r->data.txt.count++;
 362                         tmp = strtok_r(NULL, "\"", &saveptr);
 363                 }
 364
 365                 break;
 366         default:
 367                 DEBUG(0, ("Got a qytpe of %d\n", rrec->rr_type));
 368                 return DNS_ERR(NOT_IMPLEMENTED);
 369         }
 370
 371 done:
 372
 373         return WERR_OK;
 374 }
 375
 376
 377 static WERROR handle_one_update(struct dns_server *dns,
 378                                 TALLOC_CTX *mem_ctx,
 379                                 const struct dns_name_question *zone,
 380                                 const struct dns_res_rec *update)
 381 {
 382         struct dnsp_DnssrvRpcRecord *recs = NULL;
 383         uint16_t rcount = 0;
 384         struct ldb_dn *dn;
 385         uint16_t i;
 386         WERROR werror;
 387         bool needs_add = false;
 388
 389         DEBUG(2, ("Looking at record: \n"));
 390         if (DEBUGLVL(2)) {
 391                 NDR_PRINT_DEBUG(dns_res_rec, discard_const(update));
 392         }
 393
 394         switch (update->rr_type) {
 395         case DNS_QTYPE_A:
 396                 break;
 397         case DNS_QTYPE_NS:
 398                 break;
 399         case DNS_QTYPE_CNAME:
 400                 break;
 401         case DNS_QTYPE_SOA:
 402                 break;
 403         case DNS_QTYPE_PTR:
 404                 break;
 405         case DNS_QTYPE_MX:
 406                 break;
 407         case DNS_QTYPE_AAAA:
 408                 break;
 409         case DNS_QTYPE_SRV:
 410                 break;
 411         case DNS_QTYPE_TXT:
 412                 break;
 413         default:
 414                 DEBUG(0, ("Can't handle updates of type %u yet\n",
 415                           update->rr_type));
 416                 return DNS_ERR(NOT_IMPLEMENTED);
 417         }
 418
 419         werror = dns_name2dn(dns, mem_ctx, update->name, &dn);
 420         W_ERROR_NOT_OK_RETURN(werror);
 421
 422         werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rcount);
 423         if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 424                 recs = NULL;
 425                 rcount = 0;
 426                 needs_add = true;
 427                 werror = WERR_OK;
 428         }
 429         W_ERROR_NOT_OK_RETURN(werror);
 430
 431         if (update->rr_class == zone->question_class) {
 432                 if (update->rr_type == DNS_QTYPE_CNAME) {
 433                         /*
 434                          * If there is a record in the directory
 435                          * that's not a CNAME, ignore update
 436                          */
 437                         for (i = 0; i < rcount; i++) {
 438                                 if (recs[i].wType != DNS_TYPE_CNAME) {
 439                                         DEBUG(0, ("Skipping update\n"));
 440                                         return WERR_OK;
 441                                 }
 442                                 break;
 443                         }
 444
 445                         /*
 446                          * There should be no entries besides one CNAME record
 447                          * per name, so replace everything with the new CNAME
 448                          */
 449
 450                         rcount = 1;
 451                         recs = talloc_realloc(mem_ctx, recs,
 452                                         struct dnsp_DnssrvRpcRecord, rcount);
 453                         W_ERROR_HAVE_NO_MEMORY(recs);
 454
 455                         werror = dns_rr_to_dnsp(recs, update, &recs[0]);
 456                         W_ERROR_NOT_OK_RETURN(werror);
 457
 458                         werror = dns_replace_records(dns, mem_ctx, dn,
 459                                                      needs_add, recs, rcount);
 460                         W_ERROR_NOT_OK_RETURN(werror);
 461
 462                         return WERR_OK;
 463                 } else {
 464                         /*
 465                          * If there is a CNAME record for this name,
 466                          * ignore update
 467                          */
 468                         for (i = 0; i < rcount; i++) {
 469                                 if (recs[i].wType == DNS_TYPE_CNAME) {
 470                                         DEBUG(0, ("Skipping update\n"));
 471                                         return WERR_OK;
 472                                 }
 473                         }
 474                 }
 475                 if (update->rr_type == DNS_QTYPE_SOA) {
 476                         bool found = false;
 477
 478                         /*
 479                          * If the zone has no SOA record?? or update's
 480                          * serial number is smaller than existing SOA's,
 481                          * ignore update
 482                          */
 483                         for (i = 0; i < rcount; i++) {
 484                                 if (recs[i].wType == DNS_TYPE_SOA) {
 485                                         uint16_t n, o;
 486
 487                                         n = update->rdata.soa_record.serial;
 488                                         o = recs[i].data.soa.serial;
 489                                         /*
 490                                          * TODO: Implement RFC 1982 comparison
 491                                          * logic for RFC2136
 492                                          */
 493                                         if (n <= o) {
 494                                                 DEBUG(0, ("Skipping update\n"));
 495                                                 return WERR_OK;
 496                                         }
 497                                         found = true;
 498                                         break;
 499                                 }
 500                         }
 501                         if (!found) {
 502                                 DEBUG(0, ("Skipping update\n"));
 503                                 return WERR_OK;
 504                         }
 505
 506                         werror = dns_rr_to_dnsp(mem_ctx, update, &recs[i]);
 507                         W_ERROR_NOT_OK_RETURN(werror);
 508
 509                         for (i++; i < rcount; i++) {
 510                                 if (recs[i].wType != DNS_TYPE_SOA) {
 511                                         continue;
 512                                 }
 513
 514                                 ZERO_STRUCT(recs[i]);
 515                         }
 516
 517                         werror = dns_replace_records(dns, mem_ctx, dn,
 518                                                      needs_add, recs, rcount);
 519                         W_ERROR_NOT_OK_RETURN(werror);
 520
 521                         return WERR_OK;
 522                 }
 523
 524                 recs = talloc_realloc(mem_ctx, recs,
 525                                 struct dnsp_DnssrvRpcRecord, rcount+1);
 526                 W_ERROR_HAVE_NO_MEMORY(recs);
 527
 528                 werror = dns_rr_to_dnsp(recs, update, &recs[rcount]);
 529                 W_ERROR_NOT_OK_RETURN(werror);
 530
 531                 for (i = 0; i < rcount; i++) {
 532                         if (!dns_records_match(&recs[i], &recs[rcount])) {
 533                                 continue;
 534                         }
 535
 536                         recs[i] = recs[rcount];
 537
 538                         werror = dns_replace_records(dns, mem_ctx, dn,
 539                                                      needs_add, recs, rcount);
 540                         W_ERROR_NOT_OK_RETURN(werror);
 541
 542                         return WERR_OK;
 543                 }
 544
 545                 werror = dns_replace_records(dns, mem_ctx, dn,
 546                                              needs_add, recs, rcount+1);
 547                 W_ERROR_NOT_OK_RETURN(werror);
 548
 549                 return WERR_OK;
 550         } else if (update->rr_class == DNS_QCLASS_ANY) {
 551                 if (update->rr_type == DNS_QTYPE_ALL) {
 552                         if (dns_name_equal(update->name, zone->name)) {
 553                                 for (i = 0; i < rcount; i++) {
 554
 555                                         if (recs[i].wType == DNS_TYPE_SOA) {
 556                                                 continue;
 557                                         }
 558
 559                                         if (recs[i].wType == DNS_TYPE_NS) {
 560                                                 continue;
 561                                         }
 562
 563                                         ZERO_STRUCT(recs[i]);
 564                                 }
 565
 566                         } else {
 567                                 for (i = 0; i < rcount; i++) {
 568                                         ZERO_STRUCT(recs[i]);
 569                                 }
 570                         }
 571
 572                 } else if (dns_name_equal(update->name, zone->name)) {
 573
 574                         if (update->rr_type == DNS_QTYPE_SOA) {
 575                                 return WERR_OK;
 576                         }
 577
 578                         if (update->rr_type == DNS_QTYPE_NS) {
 579                                 return WERR_OK;
 580                         }
 581                 }
 582                 for (i = 0; i < rcount; i++) {
 583                         if (recs[i].wType == update->rr_type) {
 584                                 ZERO_STRUCT(recs[i]);
 585                         }
 586                 }
 587
 588                 werror = dns_replace_records(dns, mem_ctx, dn,
 589                                              needs_add, recs, rcount);
 590                 W_ERROR_NOT_OK_RETURN(werror);
 591
 592                 return WERR_OK;
 593         } else if (update->rr_class == DNS_QCLASS_NONE) {
 594                 struct dnsp_DnssrvRpcRecord *del_rec;
 595
 596                 if (update->rr_type == DNS_QTYPE_SOA) {
 597                         return WERR_OK;
 598                 }
 599                 if (update->rr_type == DNS_QTYPE_NS) {
 600                         bool found = false;
 601                         struct dnsp_DnssrvRpcRecord *ns_rec = talloc(mem_ctx,
 602                                                 struct dnsp_DnssrvRpcRecord);
 603                         W_ERROR_HAVE_NO_MEMORY(ns_rec);
 604
 605
 606                         werror = dns_rr_to_dnsp(ns_rec, update, ns_rec);
 607                         W_ERROR_NOT_OK_RETURN(werror);
 608
 609                         for (i = 0; i < rcount; i++) {
 610                                 if (dns_records_match(ns_rec, &recs[i])) {
 611                                         found = true;
 612                                         break;
 613                                 }
 614                         }
 615                         if (found) {
 616                                 return WERR_OK;
 617                         }
 618                 }
 619
 620                 del_rec = talloc(mem_ctx, struct dnsp_DnssrvRpcRecord);
 621                 W_ERROR_HAVE_NO_MEMORY(del_rec);
 622
 623                 werror = dns_rr_to_dnsp(del_rec, update, del_rec);
 624                 W_ERROR_NOT_OK_RETURN(werror);
 625
 626                 for (i = 0; i < rcount; i++) {
 627                         if (dns_records_match(del_rec, &recs[i])) {
 628                                 ZERO_STRUCT(recs[i]);
 629                         }
 630                 }
 631
 632                 werror = dns_replace_records(dns, mem_ctx, dn,
 633                                              needs_add, recs, rcount);
 634                 W_ERROR_NOT_OK_RETURN(werror);
 635         }
 636
 637         return WERR_OK;
 638 }
 639
 640 static WERROR handle_updates(struct dns_server *dns,
 641                              TALLOC_CTX *mem_ctx,
 642                              const struct dns_name_question *zone,
 643                              const struct dns_res_rec *prereqs, uint16_t pcount,
 644                              struct dns_res_rec *updates, uint16_t upd_count)
 645 {
 646         struct ldb_dn *zone_dn = NULL;
 647         WERROR werror = WERR_OK;
 648         int ret;
 649         uint16_t ri;
 650         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 651
 652         werror = dns_name2dn(dns, tmp_ctx, zone->name, &zone_dn);
 653         W_ERROR_NOT_OK_RETURN(werror);
 654
 655         ret = ldb_transaction_start(dns->samdb);
 656         if (ret != LDB_SUCCESS) {
 657                 return DNS_ERR(SERVER_FAILURE);
 658         }
 659
 660         werror = check_prerequisites(dns, tmp_ctx, zone, prereqs, pcount);
 661         W_ERROR_NOT_OK_GOTO(werror, failed);
 662
 663         DEBUG(0, ("update count is %u\n", upd_count));
 664
 665         for (ri = 0; ri < upd_count; ri++) {
 666                 werror = handle_one_update(dns, tmp_ctx, zone,
 667                                            &updates[ri]);
 668                 W_ERROR_NOT_OK_GOTO(werror, failed);
 669         }
 670
 671         ldb_transaction_commit(dns->samdb);
 672         TALLOC_FREE(tmp_ctx);
 673         return WERR_OK;
 674
 675 failed:
 676         ldb_transaction_cancel(dns->samdb);
 677         TALLOC_FREE(tmp_ctx);
 678         return werror;
 679
 680 }
 681
 682 WERROR dns_server_process_update(struct dns_server *dns,
 683                                  TALLOC_CTX *mem_ctx,
 684                                  struct dns_name_packet *in,
 685                                  struct dns_res_rec **prereqs,    uint16_t *prereq_count,
 686                                  struct dns_res_rec **updates,    uint16_t *update_count,
 687                                  struct dns_res_rec **additional, uint16_t *arcount)
 688 {
 689         struct dns_name_question *zone;
 690         const struct dns_server_zone *z;
 691         size_t host_part_len = 0;
 692         WERROR werror = DNS_ERR(NOT_IMPLEMENTED);
 693
 694         if (in->qdcount != 1) {
 695                 return DNS_ERR(FORMAT_ERROR);
 696         }
 697
 698         zone = &in->questions[0];
 699
 700         if (zone->question_class != DNS_QCLASS_IN &&
 701             zone->question_class != DNS_QCLASS_ANY) {
 702                 return DNS_ERR(NOT_IMPLEMENTED);
 703         }
 704
 705         if (zone->question_type != DNS_QTYPE_SOA) {
 706                 return DNS_ERR(FORMAT_ERROR);
 707         }
 708
 709         DEBUG(2, ("Got a dns update request.\n"));
 710
 711         for (z = dns->zones; z != NULL; z = z->next) {
 712                 bool match;
 713
 714                 match = dns_name_match(z->name, zone->name, &host_part_len);
 715                 if (match) {
 716                         break;
 717                 }
 718         }
 719
 720         if (z == NULL) {
 721                 DEBUG(0, ("We're not authorative for this zone\n"));
 722                 return DNS_ERR(NOTAUTH);
 723         }
 724
 725         if (host_part_len != 0) {
 726                 /* TODO: We need to delegate this one */
 727                 DEBUG(0, ("Would have to delegate zones.\n"));
 728                 return DNS_ERR(NOT_IMPLEMENTED);
 729         }
 730
 731         *prereq_count = in->ancount;
 732         *prereqs = in->answers;
 733         werror = check_prerequisites(dns, mem_ctx, in->questions, *prereqs,
 734                                      *prereq_count);
 735         W_ERROR_NOT_OK_RETURN(werror);
 736
 737         /* TODO: Check if update is allowed, we probably want "always",
 738          * key-based GSSAPI, key-based bind-style TSIG and "never" as
 739          * smb.conf options. */
 740         if (lpcfg_allow_dns_updates(dns->task->lp_ctx) != DNS_UPDATE_ON) {
 741                 DEBUG(0, ("Update not allowed.\n"));
 742                 return DNS_ERR(REFUSED);
 743         }
 744
 745         *update_count = in->nscount;
 746         *updates = in->nsrecs;
 747         werror = update_prescan(in->questions, *updates, *update_count);
 748         W_ERROR_NOT_OK_RETURN(werror);
 749
 750
 751         werror = handle_updates(dns, mem_ctx, in->questions, *prereqs,
 752                                 *prereq_count, *updates, *update_count);
 753         W_ERROR_NOT_OK_RETURN(werror);
 754
 755         return werror;
 756 }