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 "param/loadparm.h"
  30 #include "dsdb/samdb/samdb.h"
  31 #include "dsdb/common/util.h"
  32 #include "smbd/service_task.h"
  33 #include "dns_server/dns_server.h"
  34 #include "auth/auth.h"
  35
  36 #undef DBGC_CLASS
  37 #define DBGC_CLASS DBGC_DNS
  38
  39 static WERROR dns_rr_to_dnsp(TALLOC_CTX *mem_ctx,
  40                              const struct dns_res_rec *rrec,
  41                              struct dnsp_DnssrvRpcRecord *r);
  42
  43 static WERROR check_one_prerequisite(struct dns_server *dns,
  44                                      TALLOC_CTX *mem_ctx,
  45                                      const struct dns_name_question *zone,
  46                                      const struct dns_res_rec *pr,
  47                                      bool *final_result)
  48 {
  49         bool match;
  50         WERROR werror;
  51         struct ldb_dn *dn;
  52         uint16_t i;
  53         bool found = false;
  54         struct dnsp_DnssrvRpcRecord *rec = NULL;
  55         struct dnsp_DnssrvRpcRecord *ans;
  56         uint16_t acount;
  57
  58         size_t host_part_len = 0;
  59
  60         *final_result = true;
  61
  62         if (pr->ttl != 0) {
  63                 return DNS_ERR(FORMAT_ERROR);
  64         }
  65
  66         match = dns_name_match(zone->name, pr->name, &host_part_len);
  67         if (!match) {
  68                 return DNS_ERR(NOTZONE);
  69         }
  70
  71         werror = dns_name2dn(dns, mem_ctx, pr->name, &dn);
  72         W_ERROR_NOT_OK_RETURN(werror);
  73
  74         if (pr->rr_class == DNS_QCLASS_ANY) {
  75
  76                 if (pr->length != 0) {
  77                         return DNS_ERR(FORMAT_ERROR);
  78                 }
  79
  80
  81                 if (pr->rr_type == DNS_QTYPE_ALL) {
  82                         /*
  83                          */
  84                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
  85                         if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
  86                                 return DNS_ERR(NAME_ERROR);
  87                         }
  88                         W_ERROR_NOT_OK_RETURN(werror);
  89
  90                         if (acount == 0) {
  91                                 return DNS_ERR(NAME_ERROR);
  92                         }
  93                 } else {
  94                         /*
  95                          */
  96                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
  97                         if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
  98                                 return DNS_ERR(NXRRSET);
  99                         }
 100                         if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 101                                 return DNS_ERR(NXRRSET);
 102                         }
 103                         W_ERROR_NOT_OK_RETURN(werror);
 104
 105                         for (i = 0; i < acount; i++) {
 106                                 if (ans[i].wType == (enum dns_record_type) pr->rr_type) {
 107                                         found = true;
 108                                         break;
 109                                 }
 110                         }
 111                         if (!found) {
 112                                 return DNS_ERR(NXRRSET);
 113                         }
 114                 }
 115
 116                 /*
 117                  * RFC2136 3.2.5 doesn't actually mention the need to return
 118                  * OK here, but otherwise we'd always return a FORMAT_ERROR
 119                  * later on. This also matches Microsoft DNS behavior.
 120                  */
 121                 return WERR_OK;
 122         }
 123
 124         if (pr->rr_class == DNS_QCLASS_NONE) {
 125                 if (pr->length != 0) {
 126                         return DNS_ERR(FORMAT_ERROR);
 127                 }
 128
 129                 if (pr->rr_type == DNS_QTYPE_ALL) {
 130                         /*
 131                          */
 132                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
 133                         if (W_ERROR_EQUAL(werror, WERR_OK)) {
 134                                 return DNS_ERR(YXDOMAIN);
 135                         }
 136                 } else {
 137                         /*
 138                          */
 139                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
 140                         if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
 141                                 werror = WERR_OK;
 142                         }
 143                         if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 144                                 werror = WERR_OK;
 145                         }
 146
 147                         for (i = 0; i < acount; i++) {
 148                                 if (ans[i].wType == (enum dns_record_type) pr->rr_type) {
 149                                         found = true;
 150                                         break;
 151                                 }
 152                         }
 153                         if (found) {
 154                                 return DNS_ERR(YXRRSET);
 155                         }
 156                 }
 157
 158                 /*
 159                  * RFC2136 3.2.5 doesn't actually mention the need to return
 160                  * OK here, but otherwise we'd always return a FORMAT_ERROR
 161                  * later on. This also matches Microsoft DNS behavior.
 162                  */
 163                 return WERR_OK;
 164         }
 165
 166         if (pr->rr_class != zone->question_class) {
 167                 return DNS_ERR(FORMAT_ERROR);
 168         }
 169
 170         *final_result = false;
 171
 172         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
 173         if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
 174                 return DNS_ERR(NXRRSET);
 175         }
 176         if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 177                 return DNS_ERR(NXRRSET);
 178         }
 179         W_ERROR_NOT_OK_RETURN(werror);
 180
 181         rec = talloc_zero(mem_ctx, struct dnsp_DnssrvRpcRecord);
 182         W_ERROR_HAVE_NO_MEMORY(rec);
 183
 184         werror = dns_rr_to_dnsp(rec, pr, rec);
 185         W_ERROR_NOT_OK_RETURN(werror);
 186
 187         for (i = 0; i < acount; i++) {
 188                 if (dns_records_match(rec, &ans[i])) {
 189                         found = true;
 190                         break;
 191                 }
 192         }
 193
 194         if (!found) {
 195                 return DNS_ERR(NXRRSET);
 196         }
 197
 198         return WERR_OK;
 199 }
 200
 201 static WERROR check_prerequisites(struct dns_server *dns,
 202                                   TALLOC_CTX *mem_ctx,
 203                                   const struct dns_name_question *zone,
 204                                   const struct dns_res_rec *prereqs, uint16_t count)
 205 {
 206         uint16_t i;
 207         WERROR final_error = WERR_OK;
 208
 209         for (i = 0; i < count; i++) {
 210                 bool final;
 211                 WERROR werror;
 212
 213                 werror = check_one_prerequisite(dns, mem_ctx, zone,
 214                                                 &prereqs[i], &final);
 215                 if (!W_ERROR_IS_OK(werror)) {
 216                         if (final) {
 217                                 return werror;
 218                         }
 219                         if (W_ERROR_IS_OK(final_error)) {
 220                                 final_error = werror;
 221                         }
 222                 }
 223         }
 224
 225         if (!W_ERROR_IS_OK(final_error)) {
 226                 return final_error;
 227         }
 228
 229         return WERR_OK;
 230 }
 231
 232 static WERROR update_prescan(const struct dns_name_question *zone,
 233                              const struct dns_res_rec *updates, uint16_t count)
 234 {
 235         const struct dns_res_rec *r;
 236         uint16_t i;
 237         size_t host_part_len;
 238         bool match;
 239
 240         for (i = 0; i < count; i++) {
 241                 r = &updates[i];
 242                 match = dns_name_match(zone->name, r->name, &host_part_len);
 243                 if (!match) {
 244                         return DNS_ERR(NOTZONE);
 245                 }
 246                 if (zone->question_class == r->rr_class) {
 247                         if (r->rr_type == DNS_QTYPE_ALL) {
 248                                 return DNS_ERR(FORMAT_ERROR);
 249                         }
 250                         if (r->rr_type == DNS_QTYPE_AXFR) {
 251                                 return DNS_ERR(FORMAT_ERROR);
 252                         }
 253                         if (r->rr_type == DNS_QTYPE_MAILB) {
 254                                 return DNS_ERR(FORMAT_ERROR);
 255                         }
 256                         if (r->rr_type == DNS_QTYPE_MAILA) {
 257                                 return DNS_ERR(FORMAT_ERROR);
 258                         }
 259                 } else if (r->rr_class == DNS_QCLASS_ANY) {
 260                         if (r->ttl != 0) {
 261                                 return DNS_ERR(FORMAT_ERROR);
 262                         }
 263                         if (r->length != 0) {
 264                                 return DNS_ERR(FORMAT_ERROR);
 265                         }
 266                         if (r->rr_type == DNS_QTYPE_AXFR) {
 267                                 return DNS_ERR(FORMAT_ERROR);
 268                         }
 269                         if (r->rr_type == DNS_QTYPE_MAILB) {
 270                                 return DNS_ERR(FORMAT_ERROR);
 271                         }
 272                         if (r->rr_type == DNS_QTYPE_MAILA) {
 273                                 return DNS_ERR(FORMAT_ERROR);
 274                         }
 275                 } else if (r->rr_class == DNS_QCLASS_NONE) {
 276                         if (r->ttl != 0) {
 277                                 return DNS_ERR(FORMAT_ERROR);
 278                         }
 279                         if (r->rr_type == DNS_QTYPE_ALL) {
 280                                 return DNS_ERR(FORMAT_ERROR);
 281                         }
 282                         if (r->rr_type == DNS_QTYPE_AXFR) {
 283                                 return DNS_ERR(FORMAT_ERROR);
 284                         }
 285                         if (r->rr_type == DNS_QTYPE_MAILB) {
 286                                 return DNS_ERR(FORMAT_ERROR);
 287                         }
 288                         if (r->rr_type == DNS_QTYPE_MAILA) {
 289                                 return DNS_ERR(FORMAT_ERROR);
 290                         }
 291                 } else {
 292                         return DNS_ERR(FORMAT_ERROR);
 293                 }
 294         }
 295         return WERR_OK;
 296 }
 297
 298 static WERROR dns_rr_to_dnsp(TALLOC_CTX *mem_ctx,
 299                              const struct dns_res_rec *rrec,
 300                              struct dnsp_DnssrvRpcRecord *r)
 301 {
 302         enum ndr_err_code ndr_err;
 303
 304         if (rrec->rr_type == DNS_QTYPE_ALL) {
 305                 return DNS_ERR(FORMAT_ERROR);
 306         }
 307
 308         ZERO_STRUCTP(r);
 309
 310         r->wType = (enum dns_record_type) rrec->rr_type;
 311         r->dwTtlSeconds = rrec->ttl;
 312         r->rank = DNS_RANK_ZONE;
 313
 314         /* If we get QCLASS_ANY, we're done here */
 315         if (rrec->rr_class == DNS_QCLASS_ANY) {
 316                 goto done;
 317         }
 318
 319         switch(rrec->rr_type) {
 320         case DNS_QTYPE_A:
 321                 r->data.ipv4 = talloc_strdup(mem_ctx, rrec->rdata.ipv4_record);
 322                 W_ERROR_HAVE_NO_MEMORY(r->data.ipv4);
 323                 break;
 324         case DNS_QTYPE_AAAA:
 325                 r->data.ipv6 = talloc_strdup(mem_ctx, rrec->rdata.ipv6_record);
 326                 W_ERROR_HAVE_NO_MEMORY(r->data.ipv6);
 327                 break;
 328         case DNS_QTYPE_NS:
 329                 r->data.ns = talloc_strdup(mem_ctx, rrec->rdata.ns_record);
 330                 W_ERROR_HAVE_NO_MEMORY(r->data.ns);
 331                 break;
 332         case DNS_QTYPE_CNAME:
 333                 r->data.cname = talloc_strdup(mem_ctx, rrec->rdata.cname_record);
 334                 W_ERROR_HAVE_NO_MEMORY(r->data.cname);
 335                 break;
 336         case DNS_QTYPE_SRV:
 337                 r->data.srv.wPriority = rrec->rdata.srv_record.priority;
 338                 r->data.srv.wWeight = rrec->rdata.srv_record.weight;
 339                 r->data.srv.wPort = rrec->rdata.srv_record.port;
 340                 r->data.srv.nameTarget = talloc_strdup(mem_ctx,
 341                                 rrec->rdata.srv_record.target);
 342                 W_ERROR_HAVE_NO_MEMORY(r->data.srv.nameTarget);
 343                 break;
 344         case DNS_QTYPE_PTR:
 345                 r->data.ptr = talloc_strdup(mem_ctx, rrec->rdata.ptr_record);
 346                 W_ERROR_HAVE_NO_MEMORY(r->data.ptr);
 347                 break;
 348         case DNS_QTYPE_MX:
 349                 r->data.mx.wPriority = rrec->rdata.mx_record.preference;
 350                 r->data.mx.nameTarget = talloc_strdup(mem_ctx,
 351                                 rrec->rdata.mx_record.exchange);
 352                 W_ERROR_HAVE_NO_MEMORY(r->data.mx.nameTarget);
 353                 break;
 354         case DNS_QTYPE_TXT:
 355                 ndr_err = ndr_dnsp_string_list_copy(mem_ctx,
 356                                                     &rrec->rdata.txt_record.txt,
 357                                                     &r->data.txt);
 358                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 359                         return WERR_NOT_ENOUGH_MEMORY;
 360                 }
 361
 362                 break;
 363         default:
 364                 DEBUG(0, ("Got a qytpe of %d\n", rrec->rr_type));
 365                 return DNS_ERR(NOT_IMPLEMENTED);
 366         }
 367
 368 done:
 369
 370         return WERR_OK;
 371 }
 372
 373
 374 static WERROR handle_one_update(struct dns_server *dns,
 375                                 TALLOC_CTX *mem_ctx,
 376                                 const struct dns_name_question *zone,
 377                                 const struct dns_res_rec *update,
 378                                 const struct dns_server_tkey *tkey)
 379 {
 380         struct dnsp_DnssrvRpcRecord *recs = NULL;
 381         uint16_t rcount = 0;
 382         struct ldb_dn *dn;
 383         uint16_t i;
 384         uint16_t first = 0;
 385         WERROR werror;
 386         bool tombstoned = false;
 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         case DNS_QTYPE_NS:
 397         case DNS_QTYPE_CNAME:
 398         case DNS_QTYPE_SOA:
 399         case DNS_QTYPE_PTR:
 400         case DNS_QTYPE_MX:
 401         case DNS_QTYPE_AAAA:
 402         case DNS_QTYPE_SRV:
 403         case DNS_QTYPE_TXT:
 404                 break;
 405         default:
 406                 DEBUG(0, ("Can't handle updates of type %u yet\n",
 407                           update->rr_type));
 408                 return DNS_ERR(NOT_IMPLEMENTED);
 409         }
 410
 411         werror = dns_name2dn(dns, mem_ctx, update->name, &dn);
 412         W_ERROR_NOT_OK_RETURN(werror);
 413
 414         werror = dns_common_lookup(dns->samdb, mem_ctx, dn,
 415                                    &recs, &rcount, &tombstoned);
 416         if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
 417                 needs_add = true;
 418                 werror = WERR_OK;
 419         }
 420         W_ERROR_NOT_OK_RETURN(werror);
 421
 422         if (tombstoned) {
 423                 /*
 424                  * we need to keep the existing tombstone record
 425                  * and ignore it
 426                  */
 427                 first = rcount;
 428         }
 429
 430         if (update->rr_class == zone->question_class) {
 431                 if (update->rr_type == DNS_QTYPE_CNAME) {
 432                         /*
 433                          * If there is a record in the directory
 434                          * that's not a CNAME, ignore update
 435                          */
 436                         for (i = first; i < rcount; i++) {
 437                                 if (recs[i].wType != DNS_TYPE_CNAME) {
 438                                         DEBUG(5, ("Skipping update\n"));
 439                                         return WERR_OK;
 440                                 }
 441                                 break;
 442                         }
 443
 444                         /*
 445                          * There should be no entries besides one CNAME record
 446                          * per name, so replace everything with the new CNAME
 447                          */
 448
 449                         rcount = first;
 450                         recs = talloc_realloc(mem_ctx, recs,
 451                                         struct dnsp_DnssrvRpcRecord, rcount + 1);
 452                         W_ERROR_HAVE_NO_MEMORY(recs);
 453
 454                         werror = dns_rr_to_dnsp(recs, update, &recs[rcount]);
 455                         W_ERROR_NOT_OK_RETURN(werror);
 456                         rcount += 1;
 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 = first; i < rcount; i++) {
 469                                 if (recs[i].wType == DNS_TYPE_CNAME) {
 470                                         DEBUG(5, ("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 = first; 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(5, ("Skipping update\n"));
 495                                                 return WERR_OK;
 496                                         }
 497                                         found = true;
 498                                         break;
 499                                 }
 500                         }
 501                         if (!found) {
 502                                 DEBUG(5, ("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                                 recs[i] = (struct dnsp_DnssrvRpcRecord) {
 515                                         .wType = DNS_TYPE_TOMBSTONE,
 516                                 };
 517                         }
 518
 519                         werror = dns_replace_records(dns, mem_ctx, dn,
 520                                                      needs_add, recs, rcount);
 521                         W_ERROR_NOT_OK_RETURN(werror);
 522
 523                         return WERR_OK;
 524                 }
 525
 526                 recs = talloc_realloc(mem_ctx, recs,
 527                                 struct dnsp_DnssrvRpcRecord, rcount+1);
 528                 W_ERROR_HAVE_NO_MEMORY(recs);
 529
 530                 werror = dns_rr_to_dnsp(recs, update, &recs[rcount]);
 531                 W_ERROR_NOT_OK_RETURN(werror);
 532
 533                 for (i = first; i < rcount; i++) {
 534                         if (!dns_records_match(&recs[i], &recs[rcount])) {
 535                                 continue;
 536                         }
 537
 538                         recs[i] = recs[rcount];
 539
 540                         werror = dns_replace_records(dns, mem_ctx, dn,
 541                                                      needs_add, recs, rcount);
 542                         W_ERROR_NOT_OK_RETURN(werror);
 543
 544                         return WERR_OK;
 545                 }
 546
 547                 werror = dns_replace_records(dns, mem_ctx, dn,
 548                                              needs_add, recs, rcount+1);
 549                 W_ERROR_NOT_OK_RETURN(werror);
 550
 551                 return WERR_OK;
 552         } else if (update->rr_class == DNS_QCLASS_ANY) {
 553                 if (update->rr_type == DNS_QTYPE_ALL) {
 554                         if (dns_name_equal(update->name, zone->name)) {
 555                                 for (i = first; i < rcount; i++) {
 556
 557                                         if (recs[i].wType == DNS_TYPE_SOA) {
 558                                                 continue;
 559                                         }
 560
 561                                         if (recs[i].wType == DNS_TYPE_NS) {
 562                                                 continue;
 563                                         }
 564
 565                                         recs[i] = (struct dnsp_DnssrvRpcRecord) {
 566                                                 .wType = DNS_TYPE_TOMBSTONE,
 567                                         };
 568                                 }
 569
 570                         } else {
 571                                 for (i = first; i < rcount; i++) {
 572                                         recs[i] = (struct dnsp_DnssrvRpcRecord) {
 573                                                 .wType = DNS_TYPE_TOMBSTONE,
 574                                         };
 575                                 }
 576                         }
 577
 578                 } else if (dns_name_equal(update->name, zone->name)) {
 579
 580                         if (update->rr_type == DNS_QTYPE_SOA) {
 581                                 return WERR_OK;
 582                         }
 583
 584                         if (update->rr_type == DNS_QTYPE_NS) {
 585                                 return WERR_OK;
 586                         }
 587                 }
 588                 for (i = first; i < rcount; i++) {
 589                         if (recs[i].wType == (enum dns_record_type) update->rr_type) {
 590                                 recs[i] = (struct dnsp_DnssrvRpcRecord) {
 591                                         .wType = DNS_TYPE_TOMBSTONE,
 592                                 };
 593                         }
 594                 }
 595
 596                 werror = dns_replace_records(dns, mem_ctx, dn,
 597                                              needs_add, recs, rcount);
 598                 W_ERROR_NOT_OK_RETURN(werror);
 599
 600                 return WERR_OK;
 601         } else if (update->rr_class == DNS_QCLASS_NONE) {
 602                 struct dnsp_DnssrvRpcRecord *del_rec;
 603
 604                 if (update->rr_type == DNS_QTYPE_SOA) {
 605                         return WERR_OK;
 606                 }
 607                 if (update->rr_type == DNS_QTYPE_NS) {
 608                         bool found = false;
 609                         struct dnsp_DnssrvRpcRecord *ns_rec = talloc(mem_ctx,
 610                                                 struct dnsp_DnssrvRpcRecord);
 611                         W_ERROR_HAVE_NO_MEMORY(ns_rec);
 612
 613
 614                         werror = dns_rr_to_dnsp(ns_rec, update, ns_rec);
 615                         W_ERROR_NOT_OK_RETURN(werror);
 616
 617                         for (i = first; i < rcount; i++) {
 618                                 if (dns_records_match(ns_rec, &recs[i])) {
 619                                         found = true;
 620                                         break;
 621                                 }
 622                         }
 623                         if (found) {
 624                                 return WERR_OK;
 625                         }
 626                 }
 627
 628                 del_rec = talloc(mem_ctx, struct dnsp_DnssrvRpcRecord);
 629                 W_ERROR_HAVE_NO_MEMORY(del_rec);
 630
 631                 werror = dns_rr_to_dnsp(del_rec, update, del_rec);
 632                 W_ERROR_NOT_OK_RETURN(werror);
 633
 634                 for (i = first; i < rcount; i++) {
 635                         if (dns_records_match(del_rec, &recs[i])) {
 636                                 recs[i] = (struct dnsp_DnssrvRpcRecord) {
 637                                         .wType = DNS_TYPE_TOMBSTONE,
 638                                 };
 639                         }
 640                 }
 641
 642                 werror = dns_replace_records(dns, mem_ctx, dn,
 643                                              needs_add, recs, rcount);
 644                 W_ERROR_NOT_OK_RETURN(werror);
 645         }
 646
 647         return WERR_OK;
 648 }
 649
 650 static WERROR handle_updates(struct dns_server *dns,
 651                              TALLOC_CTX *mem_ctx,
 652                              const struct dns_name_question *zone,
 653                              const struct dns_res_rec *prereqs, uint16_t pcount,
 654                              struct dns_res_rec *updates, uint16_t upd_count,
 655                              struct dns_server_tkey *tkey)
 656 {
 657         struct ldb_dn *zone_dn = NULL;
 658         WERROR werror = WERR_OK;
 659         int ret;
 660         uint16_t ri;
 661         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 662
 663         if (tkey != NULL) {
 664                 ret = ldb_set_opaque(dns->samdb, "sessionInfo", tkey->session_info);
 665                 if (ret != LDB_SUCCESS) {
 666                         DEBUG(1, ("unable to set session info\n"));
 667                         werror = DNS_ERR(SERVER_FAILURE);
 668                         goto failed;
 669                 }
 670         }
 671
 672         werror = dns_name2dn(dns, tmp_ctx, zone->name, &zone_dn);
 673         W_ERROR_NOT_OK_GOTO(werror, failed);
 674
 675         ret = ldb_transaction_start(dns->samdb);
 676         if (ret != LDB_SUCCESS) {
 677                 werror = DNS_ERR(SERVER_FAILURE);
 678                 goto failed;
 679         }
 680
 681         werror = check_prerequisites(dns, tmp_ctx, zone, prereqs, pcount);
 682         W_ERROR_NOT_OK_GOTO(werror, failed);
 683
 684         DEBUG(1, ("update count is %u\n", upd_count));
 685
 686         for (ri = 0; ri < upd_count; ri++) {
 687                 werror = handle_one_update(dns, tmp_ctx, zone,
 688                                            &updates[ri], tkey);
 689                 W_ERROR_NOT_OK_GOTO(werror, failed);
 690         }
 691
 692         ldb_transaction_commit(dns->samdb);
 693         TALLOC_FREE(tmp_ctx);
 694
 695         if (tkey != NULL) {
 696                 ldb_set_opaque(dns->samdb, "sessionInfo",
 697                                system_session(dns->task->lp_ctx));
 698         }
 699
 700         return WERR_OK;
 701
 702 failed:
 703         ldb_transaction_cancel(dns->samdb);
 704
 705         if (tkey != NULL) {
 706                 ldb_set_opaque(dns->samdb, "sessionInfo",
 707                                system_session(dns->task->lp_ctx));
 708         }
 709
 710         TALLOC_FREE(tmp_ctx);
 711         return werror;
 712
 713 }
 714
 715 static WERROR dns_update_allowed(struct dns_server *dns,
 716                                  const struct dns_request_state *state,
 717                                  struct dns_server_tkey **tkey)
 718 {
 719         if (lpcfg_allow_dns_updates(dns->task->lp_ctx) == DNS_UPDATE_ON) {
 720                 DEBUG(2, ("All updates allowed.\n"));
 721                 return WERR_OK;
 722         }
 723
 724         if (lpcfg_allow_dns_updates(dns->task->lp_ctx) == DNS_UPDATE_OFF) {
 725                 DEBUG(2, ("Updates disabled.\n"));
 726                 return DNS_ERR(REFUSED);
 727         }
 728
 729         if (state->authenticated == false ) {
 730                 DEBUG(2, ("Update not allowed for unsigned packet.\n"));
 731                 return DNS_ERR(REFUSED);
 732         }
 733
 734         *tkey = dns_find_tkey(dns->tkeys, state->key_name);
 735         if (*tkey == NULL) {
 736                 DEBUG(0, ("Authenticated, but key not found. Something is wrong.\n"));
 737                 return DNS_ERR(REFUSED);
 738         }
 739
 740         return WERR_OK;
 741 }
 742
 743
 744 WERROR dns_server_process_update(struct dns_server *dns,
 745                                  const struct dns_request_state *state,
 746                                  TALLOC_CTX *mem_ctx,
 747                                  const struct dns_name_packet *in,
 748                                  struct dns_res_rec **prereqs,    uint16_t *prereq_count,
 749                                  struct dns_res_rec **updates,    uint16_t *update_count,
 750                                  struct dns_res_rec **additional, uint16_t *arcount)
 751 {
 752         struct dns_name_question *zone;
 753         const struct dns_server_zone *z;
 754         size_t host_part_len = 0;
 755         WERROR werror = DNS_ERR(NOT_IMPLEMENTED);
 756         struct dns_server_tkey *tkey = NULL;
 757
 758         if (in->qdcount != 1) {
 759                 return DNS_ERR(FORMAT_ERROR);
 760         }
 761
 762         zone = &in->questions[0];
 763
 764         if (zone->question_class != DNS_QCLASS_IN &&
 765             zone->question_class != DNS_QCLASS_ANY) {
 766                 return DNS_ERR(NOT_IMPLEMENTED);
 767         }
 768
 769         if (zone->question_type != DNS_QTYPE_SOA) {
 770                 return DNS_ERR(FORMAT_ERROR);
 771         }
 772
 773         DEBUG(2, ("Got a dns update request.\n"));
 774
 775         for (z = dns->zones; z != NULL; z = z->next) {
 776                 bool match;
 777
 778                 match = dns_name_match(z->name, zone->name, &host_part_len);
 779                 if (match) {
 780                         break;
 781                 }
 782         }
 783
 784         if (z == NULL) {
 785                 DEBUG(1, ("We're not authoritative for this zone\n"));
 786                 return DNS_ERR(NOTAUTH);
 787         }
 788
 789         if (host_part_len != 0) {
 790                 /* TODO: We need to delegate this one */
 791                 DEBUG(1, ("Would have to delegate zone '%s'.\n", zone->name));
 792                 return DNS_ERR(NOT_IMPLEMENTED);
 793         }
 794
 795         *prereq_count = in->ancount;
 796         *prereqs = in->answers;
 797         werror = check_prerequisites(dns, mem_ctx, in->questions, *prereqs,
 798                                      *prereq_count);
 799         W_ERROR_NOT_OK_RETURN(werror);
 800
 801         werror = dns_update_allowed(dns, state, &tkey);
 802         if (!W_ERROR_IS_OK(werror)) {
 803                 return werror;
 804         }
 805
 806         *update_count = in->nscount;
 807         *updates = in->nsrecs;
 808         werror = update_prescan(in->questions, *updates, *update_count);
 809         W_ERROR_NOT_OK_RETURN(werror);
 810
 811         werror = handle_updates(dns, mem_ctx, in->questions, *prereqs,
 812                                 *prereq_count, *updates, *update_count, tkey);
 813         W_ERROR_NOT_OK_RETURN(werror);
 814
 815         return werror;
 816 }