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 "samba/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
 306         if (rrec->rr_type == DNS_QTYPE_ALL) {
 307                 return DNS_ERR(FORMAT_ERROR);
 308         }
 309
 310         ZERO_STRUCTP(r);
 311
 312         r->wType = (enum dns_record_type) rrec->rr_type;
 313         r->dwTtlSeconds = rrec->ttl;
 314         r->rank = DNS_RANK_ZONE;
 315         if (name_is_static) {
 316                 r->dwTimeStamp = 0;
 317         } else {
 318                 r->dwTimeStamp = unix_to_dns_timestamp(time(NULL));
 319         }
 320
 321         /* If we get QCLASS_ANY, we're done here */
 322         if (rrec->rr_class == DNS_QCLASS_ANY) {
 323                 goto done;
 324         }
 325
 326         switch(rrec->rr_type) {
 327         case DNS_QTYPE_A:
 328                 r->data.ipv4 = talloc_strdup(mem_ctx, rrec->rdata.ipv4_record);
 329                 W_ERROR_HAVE_NO_MEMORY(r->data.ipv4);
 330                 break;
 331         case DNS_QTYPE_AAAA:
 332                 r->data.ipv6 = talloc_strdup(mem_ctx, rrec->rdata.ipv6_record);
 333                 W_ERROR_HAVE_NO_MEMORY(r->data.ipv6);
 334                 break;
 335         case DNS_QTYPE_NS:
 336                 r->data.ns = talloc_strdup(mem_ctx, rrec->rdata.ns_record);
 337                 W_ERROR_HAVE_NO_MEMORY(r->data.ns);
 338                 break;
 339         case DNS_QTYPE_CNAME:
 340                 r->data.cname = talloc_strdup(mem_ctx, rrec->rdata.cname_record);
 341                 W_ERROR_HAVE_NO_MEMORY(r->data.cname);
 342                 break;
 343         case DNS_QTYPE_SRV:
 344                 r->data.srv.wPriority = rrec->rdata.srv_record.priority;
 345                 r->data.srv.wWeight = rrec->rdata.srv_record.weight;
 346                 r->data.srv.wPort = rrec->rdata.srv_record.port;
 347                 r->data.srv.nameTarget = talloc_strdup(mem_ctx,
 348                                 rrec->rdata.srv_record.target);
 349                 W_ERROR_HAVE_NO_MEMORY(r->data.srv.nameTarget);
 350                 break;
 351         case DNS_QTYPE_PTR:
 352                 r->data.ptr = talloc_strdup(mem_ctx, rrec->rdata.ptr_record);
 353                 W_ERROR_HAVE_NO_MEMORY(r->data.ptr);
 354                 break;
 355         case DNS_QTYPE_MX:
 356                 r->data.mx.wPriority = rrec->rdata.mx_record.preference;
 357                 r->data.mx.nameTarget = talloc_strdup(mem_ctx,
 358                                 rrec->rdata.mx_record.exchange);
 359                 W_ERROR_HAVE_NO_MEMORY(r->data.mx.nameTarget);
 360                 break;
 361         case DNS_QTYPE_TXT:
 362                 ndr_err = ndr_dnsp_string_list_copy(mem_ctx,
 363                                                     &rrec->rdata.txt_record.txt,
 364                                                     &r->data.txt);
 365                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 366                         return WERR_NOT_ENOUGH_MEMORY;
 367                 }
 368
 369                 break;
 370         default:
 371                 DEBUG(0, ("Got a qytpe of %d\n", rrec->rr_type));
 372                 return DNS_ERR(NOT_IMPLEMENTED);
 373         }
 374
 375 done:
 376
 377         return WERR_OK;
 378 }
 379
 380
 381 static WERROR handle_one_update(struct dns_server *dns,
 382                                 TALLOC_CTX *mem_ctx,
 383                                 const struct dns_name_question *zone,
 384                                 const struct dns_res_rec *update,
 385                                 const struct dns_server_tkey *tkey)
 386 {
 387         struct dnsp_DnssrvRpcRecord *recs = NULL;
 388         uint16_t rcount = 0;
 389         struct ldb_dn *dn;
 390         uint16_t i;
 391         uint16_t first = 0;
 392         WERROR werror;
 393         bool tombstoned = false;
 394         bool needs_add = false;
 395         bool name_is_static;
 396
 397         DEBUG(2, ("Looking at record: \n"));
 398         if (DEBUGLVL(2)) {
 399                 NDR_PRINT_DEBUG(dns_res_rec, discard_const(update));
 400         }
 401
 402         switch (update->rr_type) {
 403         case DNS_QTYPE_A:
 404         case DNS_QTYPE_NS:
 405         case DNS_QTYPE_CNAME:
 406         case DNS_QTYPE_SOA:
 407         case DNS_QTYPE_PTR:
 408         case DNS_QTYPE_MX:
 409         case DNS_QTYPE_AAAA:
 410         case DNS_QTYPE_SRV:
 411         case DNS_QTYPE_TXT:
 412         case DNS_QTYPE_ALL:
 413                 break;
 414         default:
 415                 DEBUG(0, ("Can't handle updates of type %u yet\n",
 416                           update->rr_type));
 417                 return DNS_ERR(NOT_IMPLEMENTED);
 418         }
 419
 420         werror = dns_name2dn(dns, mem_ctx, update->name, &dn);
 421         W_ERROR_NOT_OK_RETURN(werror);
 422
 423         werror = dns_common_lookup(dns->samdb, mem_ctx, dn,
 424                                    &recs, &rcount, &tombstoned);
 425         if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
 426                 needs_add = true;
 427                 werror = WERR_OK;
 428         }
 429         W_ERROR_NOT_OK_RETURN(werror);
 430
 431         if (tombstoned) {
 432                 /*
 433                  * we need to keep the existing tombstone record
 434                  * and ignore it
 435                  */
 436                 first = rcount;
 437         }
 438
 439         name_is_static = dns_name_is_static(recs, rcount);
 440
 441         if (update->rr_class == zone->question_class) {
 442                 if (update->rr_type == DNS_QTYPE_CNAME) {
 443                         /*
 444                          * If there is a record in the directory
 445                          * that's not a CNAME, ignore update
 446                          */
 447                         for (i = first; i < rcount; i++) {
 448                                 if (recs[i].wType != DNS_TYPE_CNAME) {
 449                                         DEBUG(5, ("Skipping update\n"));
 450                                         return WERR_OK;
 451                                 }
 452                                 break;
 453                         }
 454
 455                         /*
 456                          * There should be no entries besides one CNAME record
 457                          * per name, so replace everything with the new CNAME
 458                          */
 459
 460                         rcount = first;
 461                         recs = talloc_realloc(mem_ctx, recs,
 462                                         struct dnsp_DnssrvRpcRecord, rcount + 1);
 463                         W_ERROR_HAVE_NO_MEMORY(recs);
 464
 465                         werror = dns_rr_to_dnsp(
 466                             recs, update, &recs[rcount], name_is_static);
 467                         W_ERROR_NOT_OK_RETURN(werror);
 468                         rcount += 1;
 469
 470                         werror = dns_replace_records(dns, mem_ctx, dn,
 471                                                      needs_add, recs, rcount);
 472                         W_ERROR_NOT_OK_RETURN(werror);
 473
 474                         return WERR_OK;
 475                 } else {
 476                         /*
 477                          * If there is a CNAME record for this name,
 478                          * ignore update
 479                          */
 480                         for (i = first; i < rcount; i++) {
 481                                 if (recs[i].wType == DNS_TYPE_CNAME) {
 482                                         DEBUG(5, ("Skipping update\n"));
 483                                         return WERR_OK;
 484                                 }
 485                         }
 486                 }
 487                 if (update->rr_type == DNS_QTYPE_SOA) {
 488                         bool found = false;
 489
 490                         /*
 491                          * If the zone has no SOA record?? or update's
 492                          * serial number is smaller than existing SOA's,
 493                          * ignore update
 494                          */
 495                         for (i = first; i < rcount; i++) {
 496                                 if (recs[i].wType == DNS_TYPE_SOA) {
 497                                         uint16_t n, o;
 498
 499                                         n = update->rdata.soa_record.serial;
 500                                         o = recs[i].data.soa.serial;
 501                                         /*
 502                                          * TODO: Implement RFC 1982 comparison
 503                                          * logic for RFC2136
 504                                          */
 505                                         if (n <= o) {
 506                                                 DEBUG(5, ("Skipping update\n"));
 507                                                 return WERR_OK;
 508                                         }
 509                                         found = true;
 510                                         break;
 511                                 }
 512                         }
 513                         if (!found) {
 514                                 DEBUG(5, ("Skipping update\n"));
 515                                 return WERR_OK;
 516                         }
 517
 518                         werror = dns_rr_to_dnsp(
 519                             mem_ctx, update, &recs[i], name_is_static);
 520                         W_ERROR_NOT_OK_RETURN(werror);
 521
 522                         for (i++; i < rcount; i++) {
 523                                 if (recs[i].wType != DNS_TYPE_SOA) {
 524                                         continue;
 525                                 }
 526
 527                                 recs[i] = (struct dnsp_DnssrvRpcRecord) {
 528                                         .wType = DNS_TYPE_TOMBSTONE,
 529                                 };
 530                         }
 531
 532                         werror = dns_replace_records(dns, mem_ctx, dn,
 533                                                      needs_add, recs, rcount);
 534                         W_ERROR_NOT_OK_RETURN(werror);
 535
 536                         return WERR_OK;
 537                 }
 538
 539                 recs = talloc_realloc(mem_ctx, recs,
 540                                 struct dnsp_DnssrvRpcRecord, rcount+1);
 541                 W_ERROR_HAVE_NO_MEMORY(recs);
 542
 543                 werror =
 544                     dns_rr_to_dnsp(recs, update, &recs[rcount], name_is_static);
 545                 W_ERROR_NOT_OK_RETURN(werror);
 546
 547                 for (i = first; i < rcount; i++) {
 548                         if (!dns_records_match(&recs[i], &recs[rcount])) {
 549                                 continue;
 550                         }
 551
 552                         recs[i].data = recs[rcount].data;
 553                         recs[i].wType = recs[rcount].wType;
 554                         recs[i].dwTtlSeconds = recs[rcount].dwTtlSeconds;
 555                         recs[i].rank = recs[rcount].rank;
 556
 557                         werror = dns_replace_records(dns, mem_ctx, dn,
 558                                                      needs_add, recs, rcount);
 559                         W_ERROR_NOT_OK_RETURN(werror);
 560
 561                         return WERR_OK;
 562                 }
 563
 564                 werror = dns_replace_records(dns, mem_ctx, dn,
 565                                              needs_add, recs, rcount+1);
 566                 W_ERROR_NOT_OK_RETURN(werror);
 567
 568                 return WERR_OK;
 569         } else if (update->rr_class == DNS_QCLASS_ANY) {
 570                 if (update->rr_type == DNS_QTYPE_ALL) {
 571                         if (dns_name_equal(update->name, zone->name)) {
 572                                 for (i = first; i < rcount; i++) {
 573
 574                                         if (recs[i].wType == DNS_TYPE_SOA) {
 575                                                 continue;
 576                                         }
 577
 578                                         if (recs[i].wType == DNS_TYPE_NS) {
 579                                                 continue;
 580                                         }
 581
 582                                         recs[i] = (struct dnsp_DnssrvRpcRecord) {
 583                                                 .wType = DNS_TYPE_TOMBSTONE,
 584                                         };
 585                                 }
 586
 587                         } else {
 588                                 for (i = first; i < rcount; i++) {
 589                                         recs[i] = (struct dnsp_DnssrvRpcRecord) {
 590                                                 .wType = DNS_TYPE_TOMBSTONE,
 591                                         };
 592                                 }
 593                         }
 594
 595                 } else if (dns_name_equal(update->name, zone->name)) {
 596
 597                         if (update->rr_type == DNS_QTYPE_SOA) {
 598                                 return WERR_OK;
 599                         }
 600
 601                         if (update->rr_type == DNS_QTYPE_NS) {
 602                                 return WERR_OK;
 603                         }
 604                 }
 605                 for (i = first; i < rcount; i++) {
 606                         if (recs[i].wType == (enum dns_record_type) update->rr_type) {
 607                                 recs[i] = (struct dnsp_DnssrvRpcRecord) {
 608                                         .wType = DNS_TYPE_TOMBSTONE,
 609                                 };
 610                         }
 611                 }
 612
 613                 werror = dns_replace_records(dns, mem_ctx, dn,
 614                                              needs_add, recs, rcount);
 615                 W_ERROR_NOT_OK_RETURN(werror);
 616
 617                 return WERR_OK;
 618         } else if (update->rr_class == DNS_QCLASS_NONE) {
 619                 struct dnsp_DnssrvRpcRecord *del_rec;
 620
 621                 if (update->rr_type == DNS_QTYPE_SOA) {
 622                         return WERR_OK;
 623                 }
 624                 if (update->rr_type == DNS_QTYPE_NS) {
 625                         bool found = false;
 626                         struct dnsp_DnssrvRpcRecord *ns_rec = talloc(mem_ctx,
 627                                                 struct dnsp_DnssrvRpcRecord);
 628                         W_ERROR_HAVE_NO_MEMORY(ns_rec);
 629
 630                         werror = dns_rr_to_dnsp(
 631                             ns_rec, update, ns_rec, name_is_static);
 632                         W_ERROR_NOT_OK_RETURN(werror);
 633
 634                         for (i = first; i < rcount; i++) {
 635                                 if (dns_records_match(ns_rec, &recs[i])) {
 636                                         found = true;
 637                                         break;
 638                                 }
 639                         }
 640                         if (found) {
 641                                 return WERR_OK;
 642                         }
 643                 }
 644
 645                 del_rec = talloc(mem_ctx, struct dnsp_DnssrvRpcRecord);
 646                 W_ERROR_HAVE_NO_MEMORY(del_rec);
 647
 648                 werror =
 649                     dns_rr_to_dnsp(del_rec, update, del_rec, name_is_static);
 650                 W_ERROR_NOT_OK_RETURN(werror);
 651
 652                 for (i = first; i < rcount; i++) {
 653                         if (dns_records_match(del_rec, &recs[i])) {
 654                                 recs[i] = (struct dnsp_DnssrvRpcRecord) {
 655                                         .wType = DNS_TYPE_TOMBSTONE,
 656                                 };
 657                         }
 658                 }
 659
 660                 werror = dns_replace_records(dns, mem_ctx, dn,
 661                                              needs_add, recs, rcount);
 662                 W_ERROR_NOT_OK_RETURN(werror);
 663         }
 664
 665         return WERR_OK;
 666 }
 667
 668 static WERROR handle_updates(struct dns_server *dns,
 669                              TALLOC_CTX *mem_ctx,
 670                              const struct dns_name_question *zone,
 671                              const struct dns_res_rec *prereqs, uint16_t pcount,
 672                              struct dns_res_rec *updates, uint16_t upd_count,
 673                              struct dns_server_tkey *tkey)
 674 {
 675         struct ldb_dn *zone_dn = NULL;
 676         WERROR werror = WERR_OK;
 677         int ret;
 678         uint16_t ri;
 679         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 680
 681         if (tkey != NULL) {
 682                 ret = ldb_set_opaque(
 683                         dns->samdb,
 684                         DSDB_SESSION_INFO,
 685                         tkey->session_info);
 686                 if (ret != LDB_SUCCESS) {
 687                         DEBUG(1, ("unable to set session info\n"));
 688                         werror = DNS_ERR(SERVER_FAILURE);
 689                         goto failed;
 690                 }
 691         }
 692
 693         werror = dns_name2dn(dns, tmp_ctx, zone->name, &zone_dn);
 694         W_ERROR_NOT_OK_GOTO(werror, failed);
 695
 696         ret = ldb_transaction_start(dns->samdb);
 697         if (ret != LDB_SUCCESS) {
 698                 werror = DNS_ERR(SERVER_FAILURE);
 699                 goto failed;
 700         }
 701
 702         werror = check_prerequisites(dns, tmp_ctx, zone, prereqs, pcount);
 703         W_ERROR_NOT_OK_GOTO(werror, failed);
 704
 705         DBG_DEBUG("dns update count is %u\n", upd_count);
 706
 707         for (ri = 0; ri < upd_count; ri++) {
 708                 werror = handle_one_update(dns, tmp_ctx, zone,
 709                                            &updates[ri], tkey);
 710                 W_ERROR_NOT_OK_GOTO(werror, failed);
 711         }
 712
 713         ldb_transaction_commit(dns->samdb);
 714         TALLOC_FREE(tmp_ctx);
 715
 716         if (tkey != NULL) {
 717                 ldb_set_opaque(
 718                         dns->samdb,
 719                         DSDB_SESSION_INFO,
 720                         system_session(dns->task->lp_ctx));
 721         }
 722
 723         return WERR_OK;
 724
 725 failed:
 726         ldb_transaction_cancel(dns->samdb);
 727
 728         if (tkey != NULL) {
 729                 ldb_set_opaque(
 730                         dns->samdb,
 731                         DSDB_SESSION_INFO,
 732                         system_session(dns->task->lp_ctx));
 733         }
 734
 735         TALLOC_FREE(tmp_ctx);
 736         return werror;
 737
 738 }
 739
 740 static WERROR dns_update_allowed(struct dns_server *dns,
 741                                  const struct dns_request_state *state,
 742                                  struct dns_server_tkey **tkey)
 743 {
 744         if (lpcfg_allow_dns_updates(dns->task->lp_ctx) == DNS_UPDATE_ON) {
 745                 DEBUG(2, ("All updates allowed.\n"));
 746                 return WERR_OK;
 747         }
 748
 749         if (lpcfg_allow_dns_updates(dns->task->lp_ctx) == DNS_UPDATE_OFF) {
 750                 DEBUG(2, ("Updates disabled.\n"));
 751                 return DNS_ERR(REFUSED);
 752         }
 753
 754         if (state->authenticated == false ) {
 755                 DEBUG(2, ("Update not allowed for unsigned packet.\n"));
 756                 return DNS_ERR(REFUSED);
 757         }
 758
 759         *tkey = dns_find_tkey(dns->tkeys, state->key_name);
 760         if (*tkey == NULL) {
 761                 DEBUG(0, ("Authenticated, but key not found. Something is wrong.\n"));
 762                 return DNS_ERR(REFUSED);
 763         }
 764
 765         return WERR_OK;
 766 }
 767
 768
 769 WERROR dns_server_process_update(struct dns_server *dns,
 770                                  const struct dns_request_state *state,
 771                                  TALLOC_CTX *mem_ctx,
 772                                  const struct dns_name_packet *in,
 773                                  struct dns_res_rec **prereqs,    uint16_t *prereq_count,
 774                                  struct dns_res_rec **updates,    uint16_t *update_count,
 775                                  struct dns_res_rec **additional, uint16_t *arcount)
 776 {
 777         struct dns_name_question *zone;
 778         const struct dns_server_zone *z;
 779         size_t host_part_len = 0;
 780         WERROR werror = DNS_ERR(NOT_IMPLEMENTED);
 781         struct dns_server_tkey *tkey = NULL;
 782
 783         if (in->qdcount != 1) {
 784                 return DNS_ERR(FORMAT_ERROR);
 785         }
 786
 787         zone = &in->questions[0];
 788
 789         if (zone->question_class != DNS_QCLASS_IN &&
 790             zone->question_class != DNS_QCLASS_ANY) {
 791                 return DNS_ERR(NOT_IMPLEMENTED);
 792         }
 793
 794         if (zone->question_type != DNS_QTYPE_SOA) {
 795                 return DNS_ERR(FORMAT_ERROR);
 796         }
 797
 798         DEBUG(2, ("Got a dns update request.\n"));
 799
 800         for (z = dns->zones; z != NULL; z = z->next) {
 801                 bool match;
 802
 803                 match = dns_name_match(z->name, zone->name, &host_part_len);
 804                 if (match) {
 805                         break;
 806                 }
 807         }
 808
 809         if (z == NULL) {
 810                 DEBUG(1, ("We're not authoritative for this zone\n"));
 811                 return DNS_ERR(NOTAUTH);
 812         }
 813
 814         if (host_part_len != 0) {
 815                 /* TODO: We need to delegate this one */
 816                 DEBUG(1, ("Would have to delegate zone '%s'.\n", zone->name));
 817                 return DNS_ERR(NOT_IMPLEMENTED);
 818         }
 819
 820         *prereq_count = in->ancount;
 821         *prereqs = in->answers;
 822         werror = check_prerequisites(dns, mem_ctx, in->questions, *prereqs,
 823                                      *prereq_count);
 824         W_ERROR_NOT_OK_RETURN(werror);
 825
 826         werror = dns_update_allowed(dns, state, &tkey);
 827         if (!W_ERROR_IS_OK(werror)) {
 828                 return werror;
 829         }
 830
 831         *update_count = in->nscount;
 832         *updates = in->nsrecs;
 833         werror = update_prescan(in->questions, *updates, *update_count);
 834         W_ERROR_NOT_OK_RETURN(werror);
 835
 836         werror = handle_updates(dns, mem_ctx, in->questions, *prereqs,
 837                                 *prereq_count, *updates, *update_count, tkey);
 838         W_ERROR_NOT_OK_RETURN(werror);
 839
 840         return werror;
 841 }