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                              bool name_is_static);
  43
  44 static WERROR check_one_prerequisite(struct dns_server *dns,
  45                                      TALLOC_CTX *mem_ctx,
  46                                      const struct dns_name_question *zone,
  47                                      const struct dns_res_rec *pr,
  48                                      bool *final_result)
  49 {
  50         bool match;
  51         WERROR werror;
  52         struct ldb_dn *dn;
  53         uint16_t i;
  54         bool found = false;
  55         struct dnsp_DnssrvRpcRecord *rec = NULL;
  56         struct dnsp_DnssrvRpcRecord *ans;
  57         uint16_t acount;
  58
  59         size_t host_part_len = 0;
  60
  61         *final_result = true;
  62
  63         if (pr->ttl != 0) {
  64                 return DNS_ERR(FORMAT_ERROR);
  65         }
  66
  67         match = dns_name_match(zone->name, pr->name, &host_part_len);
  68         if (!match) {
  69                 return DNS_ERR(NOTZONE);
  70         }
  71
  72         werror = dns_name2dn(dns, mem_ctx, pr->name, &dn);
  73         W_ERROR_NOT_OK_RETURN(werror);
  74
  75         if (pr->rr_class == DNS_QCLASS_ANY) {
  76
  77                 if (pr->length != 0) {
  78                         return DNS_ERR(FORMAT_ERROR);
  79                 }
  80
  81
  82                 if (pr->rr_type == DNS_QTYPE_ALL) {
  83                         /*
  84                          */
  85                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
  86                         if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
  87                                 return DNS_ERR(NAME_ERROR);
  88                         }
  89                         W_ERROR_NOT_OK_RETURN(werror);
  90
  91                         if (acount == 0) {
  92                                 return DNS_ERR(NAME_ERROR);
  93                         }
  94                 } else {
  95                         /*
  96                          */
  97                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
  98                         if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
  99                                 return DNS_ERR(NXRRSET);
 100                         }
 101                         if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 102                                 return DNS_ERR(NXRRSET);
 103                         }
 104                         W_ERROR_NOT_OK_RETURN(werror);
 105
 106                         for (i = 0; i < acount; i++) {
 107                                 if (ans[i].wType == (enum dns_record_type) pr->rr_type) {
 108                                         found = true;
 109                                         break;
 110                                 }
 111                         }
 112                         if (!found) {
 113                                 return DNS_ERR(NXRRSET);
 114                         }
 115                 }
 116
 117                 /*
 118                  * RFC2136 3.2.5 doesn't actually mention the need to return
 119                  * OK here, but otherwise we'd always return a FORMAT_ERROR
 120                  * later on. This also matches Microsoft DNS behavior.
 121                  */
 122                 return WERR_OK;
 123         }
 124
 125         if (pr->rr_class == DNS_QCLASS_NONE) {
 126                 if (pr->length != 0) {
 127                         return DNS_ERR(FORMAT_ERROR);
 128                 }
 129
 130                 if (pr->rr_type == DNS_QTYPE_ALL) {
 131                         /*
 132                          */
 133                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
 134                         if (W_ERROR_EQUAL(werror, WERR_OK)) {
 135                                 return DNS_ERR(YXDOMAIN);
 136                         }
 137                 } else {
 138                         /*
 139                          */
 140                         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
 141                         if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
 142                                 werror = WERR_OK;
 143                         }
 144                         if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 145                                 werror = WERR_OK;
 146                         }
 147
 148                         for (i = 0; i < acount; i++) {
 149                                 if (ans[i].wType == (enum dns_record_type) pr->rr_type) {
 150                                         found = true;
 151                                         break;
 152                                 }
 153                         }
 154                         if (found) {
 155                                 return DNS_ERR(YXRRSET);
 156                         }
 157                 }
 158
 159                 /*
 160                  * RFC2136 3.2.5 doesn't actually mention the need to return
 161                  * OK here, but otherwise we'd always return a FORMAT_ERROR
 162                  * later on. This also matches Microsoft DNS behavior.
 163                  */
 164                 return WERR_OK;
 165         }
 166
 167         if (pr->rr_class != zone->question_class) {
 168                 return DNS_ERR(FORMAT_ERROR);
 169         }
 170
 171         *final_result = false;
 172
 173         werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
 174         if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
 175                 return DNS_ERR(NXRRSET);
 176         }
 177         if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 178                 return DNS_ERR(NXRRSET);
 179         }
 180         W_ERROR_NOT_OK_RETURN(werror);
 181
 182         rec = talloc_zero(mem_ctx, struct dnsp_DnssrvRpcRecord);
 183         W_ERROR_HAVE_NO_MEMORY(rec);
 184
 185         werror = dns_rr_to_dnsp(rec, pr, rec, dns_name_is_static(ans, acount));
 186         W_ERROR_NOT_OK_RETURN(werror);
 187
 188         for (i = 0; i < acount; i++) {
 189                 if (dns_records_match(rec, &ans[i])) {
 190                         found = true;
 191                         break;
 192                 }
 193         }
 194
 195         if (!found) {
 196                 return DNS_ERR(NXRRSET);
 197         }
 198
 199         return WERR_OK;
 200 }
 201
 202 static WERROR check_prerequisites(struct dns_server *dns,
 203                                   TALLOC_CTX *mem_ctx,
 204                                   const struct dns_name_question *zone,
 205                                   const struct dns_res_rec *prereqs, uint16_t count)
 206 {
 207         uint16_t i;
 208         WERROR final_error = WERR_OK;
 209
 210         for (i = 0; i < count; i++) {
 211                 bool final;
 212                 WERROR werror;
 213
 214                 werror = check_one_prerequisite(dns, mem_ctx, zone,
 215                                                 &prereqs[i], &final);
 216                 if (!W_ERROR_IS_OK(werror)) {
 217                         if (final) {
 218                                 return werror;
 219                         }
 220                         if (W_ERROR_IS_OK(final_error)) {
 221                                 final_error = werror;
 222                         }
 223                 }
 224         }
 225
 226         if (!W_ERROR_IS_OK(final_error)) {
 227                 return final_error;
 228         }
 229
 230         return WERR_OK;
 231 }
 232
 233 static WERROR update_prescan(const struct dns_name_question *zone,
 234                              const struct dns_res_rec *updates, uint16_t count)
 235 {
 236         const struct dns_res_rec *r;
 237         uint16_t i;
 238         size_t host_part_len;
 239         bool match;
 240
 241         for (i = 0; i < count; i++) {
 242                 r = &updates[i];
 243                 match = dns_name_match(zone->name, r->name, &host_part_len);
 244                 if (!match) {
 245                         return DNS_ERR(NOTZONE);
 246                 }
 247                 if (zone->question_class == r->rr_class) {
 248                         if (r->rr_type == DNS_QTYPE_ALL) {
 249                                 return DNS_ERR(FORMAT_ERROR);
 250                         }
 251                         if (r->rr_type == DNS_QTYPE_AXFR) {
 252                                 return DNS_ERR(FORMAT_ERROR);
 253                         }
 254                         if (r->rr_type == DNS_QTYPE_MAILB) {
 255                                 return DNS_ERR(FORMAT_ERROR);
 256                         }
 257                         if (r->rr_type == DNS_QTYPE_MAILA) {
 258                                 return DNS_ERR(FORMAT_ERROR);
 259                         }
 260                 } else if (r->rr_class == DNS_QCLASS_ANY) {
 261                         if (r->ttl != 0) {
 262                                 return DNS_ERR(FORMAT_ERROR);
 263                         }
 264                         if (r->length != 0) {
 265                                 return DNS_ERR(FORMAT_ERROR);
 266                         }
 267                         if (r->rr_type == DNS_QTYPE_AXFR) {
 268                                 return DNS_ERR(FORMAT_ERROR);
 269                         }
 270                         if (r->rr_type == DNS_QTYPE_MAILB) {
 271                                 return DNS_ERR(FORMAT_ERROR);
 272                         }
 273                         if (r->rr_type == DNS_QTYPE_MAILA) {
 274                                 return DNS_ERR(FORMAT_ERROR);
 275                         }
 276                 } else if (r->rr_class == DNS_QCLASS_NONE) {
 277                         if (r->ttl != 0) {
 278                                 return DNS_ERR(FORMAT_ERROR);
 279                         }
 280                         if (r->rr_type == DNS_QTYPE_ALL) {
 281                                 return DNS_ERR(FORMAT_ERROR);
 282                         }
 283                         if (r->rr_type == DNS_QTYPE_AXFR) {
 284                                 return DNS_ERR(FORMAT_ERROR);
 285                         }
 286                         if (r->rr_type == DNS_QTYPE_MAILB) {
 287                                 return DNS_ERR(FORMAT_ERROR);
 288                         }
 289                         if (r->rr_type == DNS_QTYPE_MAILA) {
 290                                 return DNS_ERR(FORMAT_ERROR);
 291                         }
 292                 } else {
 293                         return DNS_ERR(FORMAT_ERROR);
 294                 }
 295         }
 296         return WERR_OK;
 297 }
 298
 299 static WERROR dns_rr_to_dnsp(TALLOC_CTX *mem_ctx,
 300                              const struct dns_res_rec *rrec,
 301                              struct dnsp_DnssrvRpcRecord *r,
 302                              bool name_is_static)
 303 {
 304         enum ndr_err_code ndr_err;
 305         NTTIME t;
 306
 307         if (rrec->rr_type == DNS_QTYPE_ALL) {
 308                 return DNS_ERR(FORMAT_ERROR);
 309         }
 310
 311         ZERO_STRUCTP(r);
 312
 313         r->wType = (enum dns_record_type) rrec->rr_type;
 314         r->dwTtlSeconds = rrec->ttl;
 315         r->rank = DNS_RANK_ZONE;
 316         if (name_is_static) {
 317                 r->dwTimeStamp = 0;
 318         } else {
 319                 unix_to_nt_time(&t, time(NULL));
 320                 t /= 10 * 1000 * 1000;
 321                 t /= 3600;
 322                 r->dwTimeStamp = t;
 323         }
 324
 325         /* If we get QCLASS_ANY, we're done here */
 326         if (rrec->rr_class == DNS_QCLASS_ANY) {
 327                 goto done;
 328         }
 329
 330         switch(rrec->rr_type) {
 331         case DNS_QTYPE_A:
 332                 r->data.ipv4 = talloc_strdup(mem_ctx, rrec->rdata.ipv4_record);
 333                 W_ERROR_HAVE_NO_MEMORY(r->data.ipv4);
 334                 break;
 335         case DNS_QTYPE_AAAA:
 336                 r->data.ipv6 = talloc_strdup(mem_ctx, rrec->rdata.ipv6_record);
 337                 W_ERROR_HAVE_NO_MEMORY(r->data.ipv6);
 338                 break;
 339         case DNS_QTYPE_NS:
 340                 r->data.ns = talloc_strdup(mem_ctx, rrec->rdata.ns_record);
 341                 W_ERROR_HAVE_NO_MEMORY(r->data.ns);
 342                 break;
 343         case DNS_QTYPE_CNAME:
 344                 r->data.cname = talloc_strdup(mem_ctx, rrec->rdata.cname_record);
 345                 W_ERROR_HAVE_NO_MEMORY(r->data.cname);
 346                 break;
 347         case DNS_QTYPE_SRV:
 348                 r->data.srv.wPriority = rrec->rdata.srv_record.priority;
 349                 r->data.srv.wWeight = rrec->rdata.srv_record.weight;
 350                 r->data.srv.wPort = rrec->rdata.srv_record.port;
 351                 r->data.srv.nameTarget = talloc_strdup(mem_ctx,
 352                                 rrec->rdata.srv_record.target);
 353                 W_ERROR_HAVE_NO_MEMORY(r->data.srv.nameTarget);
 354                 break;
 355         case DNS_QTYPE_PTR:
 356                 r->data.ptr = talloc_strdup(mem_ctx, rrec->rdata.ptr_record);
 357                 W_ERROR_HAVE_NO_MEMORY(r->data.ptr);
 358                 break;
 359         case DNS_QTYPE_MX:
 360                 r->data.mx.wPriority = rrec->rdata.mx_record.preference;
 361                 r->data.mx.nameTarget = talloc_strdup(mem_ctx,
 362                                 rrec->rdata.mx_record.exchange);
 363                 W_ERROR_HAVE_NO_MEMORY(r->data.mx.nameTarget);
 364                 break;
 365         case DNS_QTYPE_TXT:
 366                 ndr_err = ndr_dnsp_string_list_copy(mem_ctx,
 367                                                     &rrec->rdata.txt_record.txt,
 368                                                     &r->data.txt);
 369                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 370                         return WERR_NOT_ENOUGH_MEMORY;
 371                 }
 372
 373                 break;
 374         default:
 375                 DEBUG(0, ("Got a qytpe of %d\n", rrec->rr_type));
 376                 return DNS_ERR(NOT_IMPLEMENTED);
 377         }
 378
 379 done:
 380
 381         return WERR_OK;
 382 }
 383
 384
 385 static WERROR handle_one_update(struct dns_server *dns,
 386                                 TALLOC_CTX *mem_ctx,
 387                                 const struct dns_name_question *zone,
 388                                 const struct dns_res_rec *update,
 389                                 const struct dns_server_tkey *tkey)
 390 {
 391         struct dnsp_DnssrvRpcRecord *recs = NULL;
 392         uint16_t rcount = 0;
 393         struct ldb_dn *dn;
 394         uint16_t i;
 395         uint16_t first = 0;
 396         WERROR werror;
 397         bool tombstoned = false;
 398         bool needs_add = false;
 399         bool name_is_static;
 400
 401         DEBUG(2, ("Looking at record: \n"));
 402         if (DEBUGLVL(2)) {
 403                 NDR_PRINT_DEBUG(dns_res_rec, discard_const(update));
 404         }
 405
 406         switch (update->rr_type) {
 407         case DNS_QTYPE_A:
 408         case DNS_QTYPE_NS:
 409         case DNS_QTYPE_CNAME:
 410         case DNS_QTYPE_SOA:
 411         case DNS_QTYPE_PTR:
 412         case DNS_QTYPE_MX:
 413         case DNS_QTYPE_AAAA:
 414         case DNS_QTYPE_SRV:
 415         case DNS_QTYPE_TXT:
 416                 break;
 417         default:
 418                 DEBUG(0, ("Can't handle updates of type %u yet\n",
 419                           update->rr_type));
 420                 return DNS_ERR(NOT_IMPLEMENTED);
 421         }
 422
 423         werror = dns_name2dn(dns, mem_ctx, update->name, &dn);
 424         W_ERROR_NOT_OK_RETURN(werror);
 425
 426         werror = dns_common_lookup(dns->samdb, mem_ctx, dn,
 427                                    &recs, &rcount, &tombstoned);
 428         if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
 429                 needs_add = true;
 430                 werror = WERR_OK;
 431         }
 432         W_ERROR_NOT_OK_RETURN(werror);
 433
 434         if (tombstoned) {
 435                 /*
 436                  * we need to keep the existing tombstone record
 437                  * and ignore it
 438                  */
 439                 first = rcount;
 440         }
 441
 442         name_is_static = dns_name_is_static(recs, rcount);
 443
 444         if (update->rr_class == zone->question_class) {
 445                 if (update->rr_type == DNS_QTYPE_CNAME) {
 446                         /*
 447                          * If there is a record in the directory
 448                          * that's not a CNAME, ignore update
 449                          */
 450                         for (i = first; i < rcount; i++) {
 451                                 if (recs[i].wType != DNS_TYPE_CNAME) {
 452                                         DEBUG(5, ("Skipping update\n"));
 453                                         return WERR_OK;
 454                                 }
 455                                 break;
 456                         }
 457
 458                         /*
 459                          * There should be no entries besides one CNAME record
 460                          * per name, so replace everything with the new CNAME
 461                          */
 462
 463                         rcount = first;
 464                         recs = talloc_realloc(mem_ctx, recs,
 465                                         struct dnsp_DnssrvRpcRecord, rcount + 1);
 466                         W_ERROR_HAVE_NO_MEMORY(recs);
 467
 468                         werror = dns_rr_to_dnsp(
 469                             recs, update, &recs[rcount], name_is_static);
 470                         W_ERROR_NOT_OK_RETURN(werror);
 471                         rcount += 1;
 472
 473                         werror = dns_replace_records(dns, mem_ctx, dn,
 474                                                      needs_add, recs, rcount);
 475                         W_ERROR_NOT_OK_RETURN(werror);
 476
 477                         return WERR_OK;
 478                 } else {
 479                         /*
 480                          * If there is a CNAME record for this name,
 481                          * ignore update
 482                          */
 483                         for (i = first; i < rcount; i++) {
 484                                 if (recs[i].wType == DNS_TYPE_CNAME) {
 485                                         DEBUG(5, ("Skipping update\n"));
 486                                         return WERR_OK;
 487                                 }
 488                         }
 489                 }
 490                 if (update->rr_type == DNS_QTYPE_SOA) {
 491                         bool found = false;
 492
 493                         /*
 494                          * If the zone has no SOA record?? or update's
 495                          * serial number is smaller than existing SOA's,
 496                          * ignore update
 497                          */
 498                         for (i = first; i < rcount; i++) {
 499                                 if (recs[i].wType == DNS_TYPE_SOA) {
 500                                         uint16_t n, o;
 501
 502                                         n = update->rdata.soa_record.serial;
 503                                         o = recs[i].data.soa.serial;
 504                                         /*
 505                                          * TODO: Implement RFC 1982 comparison
 506                                          * logic for RFC2136
 507                                          */
 508                                         if (n <= o) {
 509                                                 DEBUG(5, ("Skipping update\n"));
 510                                                 return WERR_OK;
 511                                         }
 512                                         found = true;
 513                                         break;
 514                                 }
 515                         }
 516                         if (!found) {
 517                                 DEBUG(5, ("Skipping update\n"));
 518                                 return WERR_OK;
 519                         }
 520
 521                         werror = dns_rr_to_dnsp(
 522                             mem_ctx, update, &recs[i], name_is_static);
 523                         W_ERROR_NOT_OK_RETURN(werror);
 524
 525                         for (i++; i < rcount; i++) {
 526                                 if (recs[i].wType != DNS_TYPE_SOA) {
 527                                         continue;
 528                                 }
 529
 530                                 recs[i] = (struct dnsp_DnssrvRpcRecord) {
 531                                         .wType = DNS_TYPE_TOMBSTONE,
 532                                 };
 533                         }
 534
 535                         werror = dns_replace_records(dns, mem_ctx, dn,
 536                                                      needs_add, recs, rcount);
 537                         W_ERROR_NOT_OK_RETURN(werror);
 538
 539                         return WERR_OK;
 540                 }
 541
 542                 recs = talloc_realloc(mem_ctx, recs,
 543                                 struct dnsp_DnssrvRpcRecord, rcount+1);
 544                 W_ERROR_HAVE_NO_MEMORY(recs);
 545
 546                 werror =
 547                     dns_rr_to_dnsp(recs, update, &recs[rcount], name_is_static);
 548                 W_ERROR_NOT_OK_RETURN(werror);
 549
 550                 for (i = first; i < rcount; i++) {
 551                         if (!dns_records_match(&recs[i], &recs[rcount])) {
 552                                 continue;
 553                         }
 554
 555                         recs[i].data = recs[rcount].data;
 556                         recs[i].wType = recs[rcount].wType;
 557                         recs[i].dwTtlSeconds = recs[rcount].dwTtlSeconds;
 558                         recs[i].rank = recs[rcount].rank;
 559
 560                         werror = dns_replace_records(dns, mem_ctx, dn,
 561                                                      needs_add, recs, rcount);
 562                         W_ERROR_NOT_OK_RETURN(werror);
 563
 564                         return WERR_OK;
 565                 }
 566
 567                 werror = dns_replace_records(dns, mem_ctx, dn,
 568                                              needs_add, recs, rcount+1);
 569                 W_ERROR_NOT_OK_RETURN(werror);
 570
 571                 return WERR_OK;
 572         } else if (update->rr_class == DNS_QCLASS_ANY) {
 573                 if (update->rr_type == DNS_QTYPE_ALL) {
 574                         if (dns_name_equal(update->name, zone->name)) {
 575                                 for (i = first; i < rcount; i++) {
 576
 577                                         if (recs[i].wType == DNS_TYPE_SOA) {
 578                                                 continue;
 579                                         }
 580
 581                                         if (recs[i].wType == DNS_TYPE_NS) {
 582                                                 continue;
 583                                         }
 584
 585                                         recs[i] = (struct dnsp_DnssrvRpcRecord) {
 586                                                 .wType = DNS_TYPE_TOMBSTONE,
 587                                         };
 588                                 }
 589
 590                         } else {
 591                                 for (i = first; i < rcount; i++) {
 592                                         recs[i] = (struct dnsp_DnssrvRpcRecord) {
 593                                                 .wType = DNS_TYPE_TOMBSTONE,
 594                                         };
 595                                 }
 596                         }
 597
 598                 } else if (dns_name_equal(update->name, zone->name)) {
 599
 600                         if (update->rr_type == DNS_QTYPE_SOA) {
 601                                 return WERR_OK;
 602                         }
 603
 604                         if (update->rr_type == DNS_QTYPE_NS) {
 605                                 return WERR_OK;
 606                         }
 607                 }
 608                 for (i = first; i < rcount; i++) {
 609                         if (recs[i].wType == (enum dns_record_type) update->rr_type) {
 610                                 recs[i] = (struct dnsp_DnssrvRpcRecord) {
 611                                         .wType = DNS_TYPE_TOMBSTONE,
 612                                 };
 613                         }
 614                 }
 615
 616                 werror = dns_replace_records(dns, mem_ctx, dn,
 617                                              needs_add, recs, rcount);
 618                 W_ERROR_NOT_OK_RETURN(werror);
 619
 620                 return WERR_OK;
 621         } else if (update->rr_class == DNS_QCLASS_NONE) {
 622                 struct dnsp_DnssrvRpcRecord *del_rec;
 623
 624                 if (update->rr_type == DNS_QTYPE_SOA) {
 625                         return WERR_OK;
 626                 }
 627                 if (update->rr_type == DNS_QTYPE_NS) {
 628                         bool found = false;
 629                         struct dnsp_DnssrvRpcRecord *ns_rec = talloc(mem_ctx,
 630                                                 struct dnsp_DnssrvRpcRecord);
 631                         W_ERROR_HAVE_NO_MEMORY(ns_rec);
 632
 633                         werror = dns_rr_to_dnsp(
 634                             ns_rec, update, ns_rec, name_is_static);
 635                         W_ERROR_NOT_OK_RETURN(werror);
 636
 637                         for (i = first; i < rcount; i++) {
 638                                 if (dns_records_match(ns_rec, &recs[i])) {
 639                                         found = true;
 640                                         break;
 641                                 }
 642                         }
 643                         if (found) {
 644                                 return WERR_OK;
 645                         }
 646                 }
 647
 648                 del_rec = talloc(mem_ctx, struct dnsp_DnssrvRpcRecord);
 649                 W_ERROR_HAVE_NO_MEMORY(del_rec);
 650
 651                 werror =
 652                     dns_rr_to_dnsp(del_rec, update, del_rec, name_is_static);
 653                 W_ERROR_NOT_OK_RETURN(werror);
 654
 655                 for (i = first; i < rcount; i++) {
 656                         if (dns_records_match(del_rec, &recs[i])) {
 657                                 recs[i] = (struct dnsp_DnssrvRpcRecord) {
 658                                         .wType = DNS_TYPE_TOMBSTONE,
 659                                 };
 660                         }
 661                 }
 662
 663                 werror = dns_replace_records(dns, mem_ctx, dn,
 664                                              needs_add, recs, rcount);
 665                 W_ERROR_NOT_OK_RETURN(werror);
 666         }
 667
 668         return WERR_OK;
 669 }
 670
 671 static WERROR handle_updates(struct dns_server *dns,
 672                              TALLOC_CTX *mem_ctx,
 673                              const struct dns_name_question *zone,
 674                              const struct dns_res_rec *prereqs, uint16_t pcount,
 675                              struct dns_res_rec *updates, uint16_t upd_count,
 676                              struct dns_server_tkey *tkey)
 677 {
 678         struct ldb_dn *zone_dn = NULL;
 679         WERROR werror = WERR_OK;
 680         int ret;
 681         uint16_t ri;
 682         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 683
 684         if (tkey != NULL) {
 685                 ret = ldb_set_opaque(
 686                         dns->samdb,
 687                         DSDB_SESSION_INFO,
 688                         tkey->session_info);
 689                 if (ret != LDB_SUCCESS) {
 690                         DEBUG(1, ("unable to set session info\n"));
 691                         werror = DNS_ERR(SERVER_FAILURE);
 692                         goto failed;
 693                 }
 694         }
 695
 696         werror = dns_name2dn(dns, tmp_ctx, zone->name, &zone_dn);
 697         W_ERROR_NOT_OK_GOTO(werror, failed);
 698
 699         ret = ldb_transaction_start(dns->samdb);
 700         if (ret != LDB_SUCCESS) {
 701                 werror = DNS_ERR(SERVER_FAILURE);
 702                 goto failed;
 703         }
 704
 705         werror = check_prerequisites(dns, tmp_ctx, zone, prereqs, pcount);
 706         W_ERROR_NOT_OK_GOTO(werror, failed);
 707
 708         DBG_DEBUG("dns update count is %u\n", upd_count);
 709
 710         for (ri = 0; ri < upd_count; ri++) {
 711                 werror = handle_one_update(dns, tmp_ctx, zone,
 712                                            &updates[ri], tkey);
 713                 W_ERROR_NOT_OK_GOTO(werror, failed);
 714         }
 715
 716         ldb_transaction_commit(dns->samdb);
 717         TALLOC_FREE(tmp_ctx);
 718
 719         if (tkey != NULL) {
 720                 ldb_set_opaque(
 721                         dns->samdb,
 722                         DSDB_SESSION_INFO,
 723                         system_session(dns->task->lp_ctx));
 724         }
 725
 726         return WERR_OK;
 727
 728 failed:
 729         ldb_transaction_cancel(dns->samdb);
 730
 731         if (tkey != NULL) {
 732                 ldb_set_opaque(
 733                         dns->samdb,
 734                         DSDB_SESSION_INFO,
 735                         system_session(dns->task->lp_ctx));
 736         }
 737
 738         TALLOC_FREE(tmp_ctx);
 739         return werror;
 740
 741 }
 742
 743 static WERROR dns_update_allowed(struct dns_server *dns,
 744                                  const struct dns_request_state *state,
 745                                  struct dns_server_tkey **tkey)
 746 {
 747         if (lpcfg_allow_dns_updates(dns->task->lp_ctx) == DNS_UPDATE_ON) {
 748                 DEBUG(2, ("All updates allowed.\n"));
 749                 return WERR_OK;
 750         }
 751
 752         if (lpcfg_allow_dns_updates(dns->task->lp_ctx) == DNS_UPDATE_OFF) {
 753                 DEBUG(2, ("Updates disabled.\n"));
 754                 return DNS_ERR(REFUSED);
 755         }
 756
 757         if (state->authenticated == false ) {
 758                 DEBUG(2, ("Update not allowed for unsigned packet.\n"));
 759                 return DNS_ERR(REFUSED);
 760         }
 761
 762         *tkey = dns_find_tkey(dns->tkeys, state->key_name);
 763         if (*tkey == NULL) {
 764                 DEBUG(0, ("Authenticated, but key not found. Something is wrong.\n"));
 765                 return DNS_ERR(REFUSED);
 766         }
 767
 768         return WERR_OK;
 769 }
 770
 771
 772 WERROR dns_server_process_update(struct dns_server *dns,
 773                                  const struct dns_request_state *state,
 774                                  TALLOC_CTX *mem_ctx,
 775                                  const struct dns_name_packet *in,
 776                                  struct dns_res_rec **prereqs,    uint16_t *prereq_count,
 777                                  struct dns_res_rec **updates,    uint16_t *update_count,
 778                                  struct dns_res_rec **additional, uint16_t *arcount)
 779 {
 780         struct dns_name_question *zone;
 781         const struct dns_server_zone *z;
 782         size_t host_part_len = 0;
 783         WERROR werror = DNS_ERR(NOT_IMPLEMENTED);
 784         struct dns_server_tkey *tkey = NULL;
 785
 786         if (in->qdcount != 1) {
 787                 return DNS_ERR(FORMAT_ERROR);
 788         }
 789
 790         zone = &in->questions[0];
 791
 792         if (zone->question_class != DNS_QCLASS_IN &&
 793             zone->question_class != DNS_QCLASS_ANY) {
 794                 return DNS_ERR(NOT_IMPLEMENTED);
 795         }
 796
 797         if (zone->question_type != DNS_QTYPE_SOA) {
 798                 return DNS_ERR(FORMAT_ERROR);
 799         }
 800
 801         DEBUG(2, ("Got a dns update request.\n"));
 802
 803         for (z = dns->zones; z != NULL; z = z->next) {
 804                 bool match;
 805
 806                 match = dns_name_match(z->name, zone->name, &host_part_len);
 807                 if (match) {
 808                         break;
 809                 }
 810         }
 811
 812         if (z == NULL) {
 813                 DEBUG(1, ("We're not authoritative for this zone\n"));
 814                 return DNS_ERR(NOTAUTH);
 815         }
 816
 817         if (host_part_len != 0) {
 818                 /* TODO: We need to delegate this one */
 819                 DEBUG(1, ("Would have to delegate zone '%s'.\n", zone->name));
 820                 return DNS_ERR(NOT_IMPLEMENTED);
 821         }
 822
 823         *prereq_count = in->ancount;
 824         *prereqs = in->answers;
 825         werror = check_prerequisites(dns, mem_ctx, in->questions, *prereqs,
 826                                      *prereq_count);
 827         W_ERROR_NOT_OK_RETURN(werror);
 828
 829         werror = dns_update_allowed(dns, state, &tkey);
 830         if (!W_ERROR_IS_OK(werror)) {
 831                 return werror;
 832         }
 833
 834         *update_count = in->nscount;
 835         *updates = in->nsrecs;
 836         werror = update_prescan(in->questions, *updates, *update_count);
 837         W_ERROR_NOT_OK_RETURN(werror);
 838
 839         werror = handle_updates(dns, mem_ctx, in->questions, *prereqs,
 840                                 *prereq_count, *updates, *update_count, tkey);
 841         W_ERROR_NOT_OK_RETURN(werror);
 842
 843         return werror;
 844 }