source4/dns_server/dns_server.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    DNS server startup
   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 "smbd/service_task.h"
  24 #include "smbd/service.h"
  25 #include "smbd/service_stream.h"
  26 #include "smbd/process_model.h"
  27 #include "lib/events/events.h"
  28 #include "lib/socket/socket.h"
  29 #include "lib/tsocket/tsocket.h"
  30 #include "libcli/util/tstream.h"
  31 #include "libcli/util/ntstatus.h"
  32 #include "system/network.h"
  33 #include "lib/stream/packet.h"
  34 #include "lib/socket/netif.h"
  35 #include "dns_server/dns_server.h"
  36 #include "param/param.h"
  37 #include "librpc/ndr/libndr.h"
  38 #include "librpc/gen_ndr/ndr_dns.h"
  39 #include "librpc/gen_ndr/ndr_dnsp.h"
  40 #include <ldb.h>
  41 #include "dsdb/samdb/samdb.h"
  42 #include "dsdb/common/util.h"
  43 #include "auth/session.h"
  44 #include "lib/util/dlinklist.h"
  45
  46 NTSTATUS server_service_dns_init(void);
  47
  48 /* hold information about one dns socket */
  49 struct dns_socket {
  50         struct dns_server *dns;
  51         struct tsocket_address *local_address;
  52 };
  53
  54 struct dns_udp_socket {
  55         struct dns_socket *dns_socket;
  56         struct tdgram_context *dgram;
  57         struct tevent_queue *send_queue;
  58 };
  59
  60 /*
  61   state of an open tcp connection
  62 */
  63 struct dns_tcp_connection {
  64         /* stream connection we belong to */
  65         struct stream_connection *conn;
  66
  67         /* the dns_server the connection belongs to */
  68         struct dns_socket *dns_socket;
  69
  70         struct tstream_context *tstream;
  71
  72         struct tevent_queue *send_queue;
  73 };
  74
  75 static void dns_tcp_terminate_connection(struct dns_tcp_connection *dnsconn, const char *reason)
  76 {
  77         stream_terminate_connection(dnsconn->conn, reason);
  78 }
  79
  80 static void dns_tcp_recv(struct stream_connection *conn, uint16_t flags)
  81 {
  82         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
  83                                                              struct dns_tcp_connection);
  84         /* this should never be triggered! */
  85         dns_tcp_terminate_connection(dnsconn, "dns_tcp_recv: called");
  86 }
  87
  88 static void dns_tcp_send(struct stream_connection *conn, uint16_t flags)
  89 {
  90         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
  91                                                              struct dns_tcp_connection);
  92         /* this should never be triggered! */
  93         dns_tcp_terminate_connection(dnsconn, "dns_tcp_send: called");
  94 }
  95
  96 static NTSTATUS dns_process(struct dns_server *dns,
  97                             TALLOC_CTX *mem_ctx,
  98                             DATA_BLOB *in,
  99                             DATA_BLOB *out)
 100 {
 101         enum ndr_err_code ndr_err;
 102         WERROR ret;
 103         struct dns_name_packet *in_packet;
 104         struct dns_name_packet *out_packet;
 105         struct dns_res_rec *answers = NULL, *nsrecs = NULL, *additional = NULL;
 106         uint16_t num_answers = 0 , num_nsrecs = 0, num_additional = 0;
 107
 108         if (in->length < 12) {
 109                 return NT_STATUS_INVALID_PARAMETER;
 110         }
 111
 112         in_packet = talloc_zero(mem_ctx, struct dns_name_packet);
 113         /* TODO: We don't really need an out_packet. */
 114         out_packet = talloc_zero(mem_ctx, struct dns_name_packet);
 115
 116         if (in_packet == NULL) return NT_STATUS_NO_MEMORY;
 117         if (out_packet == NULL) return NT_STATUS_NO_MEMORY;
 118
 119         dump_data(2, in->data, in->length);
 120
 121         ndr_err = ndr_pull_struct_blob(in, in_packet, in_packet,
 122                         (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 123         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 124                 TALLOC_FREE(in_packet);
 125                 DEBUG(0, ("Failed to parse packet %d!\n", ndr_err));
 126                 *out = *in;
 127
 128                 out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
 129                 out->data[3] |= DNS_RCODE_FORMERR;
 130
 131                 return NT_STATUS_OK;
 132         }
 133
 134         NDR_PRINT_DEBUG(dns_name_packet, in_packet);
 135         *out_packet = *in_packet;
 136         out_packet->operation |= DNS_FLAG_REPLY;
 137
 138         switch (in_packet->operation & DNS_OPCODE) {
 139         case DNS_OPCODE_QUERY:
 140
 141                 ret = dns_server_process_query(dns, out_packet, in_packet,
 142                                                &answers, &num_answers,
 143                                                &nsrecs,  &num_nsrecs,
 144                                                &additional, &num_additional);
 145
 146                 break;
 147         case DNS_OPCODE_UPDATE:
 148                 ret = dns_server_process_update(dns, out_packet, in_packet,
 149                                                 answers, num_answers,
 150                                                 &nsrecs,  &num_nsrecs,
 151                                                 &additional, &num_additional);
 152                 break;
 153         default:
 154                 ret = WERR_DNS_ERROR_RCODE_NOT_IMPLEMENTED;
 155                 break;
 156         }
 157
 158         if (W_ERROR_IS_OK(ret)) {
 159                 out_packet->ancount = num_answers;
 160                 out_packet->answers = answers;
 161
 162                 out_packet->nscount = num_nsrecs;
 163                 out_packet->nsrecs  = nsrecs;
 164
 165                 out_packet->arcount = num_additional;
 166                 out_packet->additional = additional;
 167         } else {
 168                 out_packet->operation |= werr_to_dns_err(ret);
 169         }
 170
 171         NDR_PRINT_DEBUG(dns_name_packet, out_packet);
 172         ndr_err = ndr_push_struct_blob(out, out_packet, out_packet,
 173                         (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 174         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 175                 TALLOC_FREE(in_packet);
 176                 TALLOC_FREE(out_packet);
 177                 DEBUG(0, ("Failed to push packet %d!\n", ndr_err));
 178                 *out = *in;
 179
 180                 out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
 181                 out->data[3] |= DNS_RCODE_SERVFAIL;
 182
 183                 return NT_STATUS_OK;
 184         }
 185
 186         dump_data(2, out->data, out->length);
 187         return NT_STATUS_OK;
 188 }
 189
 190 struct dns_tcp_call {
 191         struct dns_tcp_connection *dns_conn;
 192         DATA_BLOB in;
 193         DATA_BLOB out;
 194         uint8_t out_hdr[4];
 195         struct iovec out_iov[2];
 196 };
 197
 198 static void dns_tcp_call_writev_done(struct tevent_req *subreq);
 199
 200 static void dns_tcp_call_loop(struct tevent_req *subreq)
 201 {
 202         struct dns_tcp_connection *dns_conn = tevent_req_callback_data(subreq,
 203                                       struct dns_tcp_connection);
 204         struct dns_tcp_call *call;
 205         NTSTATUS status;
 206
 207         call = talloc(dns_conn, struct dns_tcp_call);
 208         if (call == NULL) {
 209                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 210                                 "no memory for dns_tcp_call");
 211                 return;
 212         }
 213         call->dns_conn = dns_conn;
 214
 215         status = tstream_read_pdu_blob_recv(subreq,
 216                                             call,
 217                                             &call->in);
 218         TALLOC_FREE(subreq);
 219         if (!NT_STATUS_IS_OK(status)) {
 220                 const char *reason;
 221
 222                 reason = talloc_asprintf(call, "dns_tcp_call_loop: "
 223                                          "tstream_read_pdu_blob_recv() - %s",
 224                                          nt_errstr(status));
 225                 if (!reason) {
 226                         reason = nt_errstr(status);
 227                 }
 228
 229                 dns_tcp_terminate_connection(dns_conn, reason);
 230                 return;
 231         }
 232
 233         DEBUG(10,("Received krb5 TCP packet of length %lu from %s\n",
 234                  (long) call->in.length,
 235                  tsocket_address_string(dns_conn->conn->remote_address, call)));
 236
 237         /* skip length header */
 238         call->in.data +=4;
 239         call->in.length -= 4;
 240
 241         /* Call dns */
 242         status = dns_process(dns_conn->dns_socket->dns, call, &call->in, &call->out);
 243         if (!NT_STATUS_IS_OK(status)) {
 244                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 245                 dns_tcp_terminate_connection(dns_conn,
 246                                 "dns_tcp_call_loop: process function failed");
 247                 return;
 248         }
 249
 250         /* First add the length of the out buffer */
 251         RSIVAL(call->out_hdr, 0, call->out.length);
 252         call->out_iov[0].iov_base = (char *) call->out_hdr;
 253         call->out_iov[0].iov_len = 4;
 254
 255         call->out_iov[1].iov_base = (char *) call->out.data;
 256         call->out_iov[1].iov_len = call->out.length;
 257
 258         subreq = tstream_writev_queue_send(call,
 259                                            dns_conn->conn->event.ctx,
 260                                            dns_conn->tstream,
 261                                            dns_conn->send_queue,
 262                                            call->out_iov, 2);
 263         if (subreq == NULL) {
 264                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 265                                 "no memory for tstream_writev_queue_send");
 266                 return;
 267         }
 268         tevent_req_set_callback(subreq, dns_tcp_call_writev_done, call);
 269
 270         /*
 271          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 272          * packet_full_request_u32 provides the pdu length then.
 273          */
 274         subreq = tstream_read_pdu_blob_send(dns_conn,
 275                                             dns_conn->conn->event.ctx,
 276                                             dns_conn->tstream,
 277                                             4, /* initial_read_size */
 278                                             packet_full_request_u32,
 279                                             dns_conn);
 280         if (subreq == NULL) {
 281                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 282                                 "no memory for tstream_read_pdu_blob_send");
 283                 return;
 284         }
 285         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 286 }
 287
 288 static void dns_tcp_call_writev_done(struct tevent_req *subreq)
 289 {
 290         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
 291                         struct dns_tcp_call);
 292         int sys_errno;
 293         int rc;
 294
 295         rc = tstream_writev_queue_recv(subreq, &sys_errno);
 296         TALLOC_FREE(subreq);
 297         if (rc == -1) {
 298                 const char *reason;
 299
 300                 reason = talloc_asprintf(call, "dns_tcp_call_writev_done: "
 301                                          "tstream_writev_queue_recv() - %d:%s",
 302                                          sys_errno, strerror(sys_errno));
 303                 if (!reason) {
 304                         reason = "dns_tcp_call_writev_done: tstream_writev_queue_recv() failed";
 305                 }
 306
 307                 dns_tcp_terminate_connection(call->dns_conn, reason);
 308                 return;
 309         }
 310
 311         /* We don't care about errors */
 312
 313         talloc_free(call);
 314 }
 315
 316 /*
 317   called when we get a new connection
 318 */
 319 static void dns_tcp_accept(struct stream_connection *conn)
 320 {
 321         struct dns_socket *dns_socket;
 322         struct dns_tcp_connection *dns_conn;
 323         struct tevent_req *subreq;
 324         int rc;
 325
 326         dns_conn = talloc_zero(conn, struct dns_tcp_connection);
 327         if (dns_conn == NULL) {
 328                 stream_terminate_connection(conn,
 329                                 "dns_tcp_accept: out of memory");
 330                 return;
 331         }
 332
 333         dns_conn->send_queue = tevent_queue_create(conn, "dns_tcp_accept");
 334         if (dns_conn->send_queue == NULL) {
 335                 stream_terminate_connection(conn,
 336                                 "dns_tcp_accept: out of memory");
 337                 return;
 338         }
 339
 340         dns_socket = talloc_get_type(conn->private_data, struct dns_socket);
 341
 342         TALLOC_FREE(conn->event.fde);
 343
 344         rc = tstream_bsd_existing_socket(dns_conn,
 345                         socket_get_fd(conn->socket),
 346                         &dns_conn->tstream);
 347         if (rc < 0) {
 348                 stream_terminate_connection(conn,
 349                                 "dns_tcp_accept: out of memory");
 350                 return;
 351         }
 352
 353         dns_conn->conn = conn;
 354         dns_conn->dns_socket = dns_socket;
 355         conn->private_data = dns_conn;
 356
 357         /*
 358          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 359          * packet_full_request_u32 provides the pdu length then.
 360          */
 361         subreq = tstream_read_pdu_blob_send(dns_conn,
 362                                             dns_conn->conn->event.ctx,
 363                                             dns_conn->tstream,
 364                                             4, /* initial_read_size */
 365                                             packet_full_request_u32,
 366                                             dns_conn);
 367         if (subreq == NULL) {
 368                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_accept: "
 369                                 "no memory for tstream_read_pdu_blob_send");
 370                 return;
 371         }
 372         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 373 }
 374
 375 static const struct stream_server_ops dns_tcp_stream_ops = {
 376         .name                   = "dns_tcp",
 377         .accept_connection      = dns_tcp_accept,
 378         .recv_handler           = dns_tcp_recv,
 379         .send_handler           = dns_tcp_send
 380 };
 381
 382 struct dns_udp_call {
 383         struct tsocket_address *src;
 384         DATA_BLOB in;
 385         DATA_BLOB out;
 386 };
 387
 388 static void dns_udp_call_sendto_done(struct tevent_req *subreq);
 389
 390 static void dns_udp_call_loop(struct tevent_req *subreq)
 391 {
 392         struct dns_udp_socket *sock = tevent_req_callback_data(subreq,
 393                                       struct dns_udp_socket);
 394         struct dns_udp_call *call;
 395         uint8_t *buf;
 396         ssize_t len;
 397         int sys_errno;
 398         NTSTATUS status;
 399
 400         call = talloc(sock, struct dns_udp_call);
 401         if (call == NULL) {
 402                 talloc_free(call);
 403                 goto done;
 404         }
 405
 406         len = tdgram_recvfrom_recv(subreq, &sys_errno,
 407                                    call, &buf, &call->src);
 408         TALLOC_FREE(subreq);
 409         if (len == -1) {
 410                 talloc_free(call);
 411                 goto done;
 412         }
 413
 414         call->in.data = buf;
 415         call->in.length = len;
 416
 417         DEBUG(10,("Received krb5 UDP packet of length %lu from %s\n",
 418                  (long)call->in.length,
 419                  tsocket_address_string(call->src, call)));
 420
 421         /* Call krb5 */
 422         status = dns_process(sock->dns_socket->dns, call, &call->in, &call->out);
 423         if (!NT_STATUS_IS_OK(status)) {
 424                 talloc_free(call);
 425                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 426                 goto done;
 427         }
 428
 429         subreq = tdgram_sendto_queue_send(call,
 430                                           sock->dns_socket->dns->task->event_ctx,
 431                                           sock->dgram,
 432                                           sock->send_queue,
 433                                           call->out.data,
 434                                           call->out.length,
 435                                           call->src);
 436         if (subreq == NULL) {
 437                 talloc_free(call);
 438                 goto done;
 439         }
 440         tevent_req_set_callback(subreq, dns_udp_call_sendto_done, call);
 441
 442 done:
 443         subreq = tdgram_recvfrom_send(sock,
 444                                       sock->dns_socket->dns->task->event_ctx,
 445                                       sock->dgram);
 446         if (subreq == NULL) {
 447                 task_server_terminate(sock->dns_socket->dns->task,
 448                                       "no memory for tdgram_recvfrom_send",
 449                                       true);
 450                 return;
 451         }
 452         tevent_req_set_callback(subreq, dns_udp_call_loop, sock);
 453 }
 454
 455 static void dns_udp_call_sendto_done(struct tevent_req *subreq)
 456 {
 457         struct dns_udp_call *call = tevent_req_callback_data(subreq,
 458                                        struct dns_udp_call);
 459         ssize_t ret;
 460         int sys_errno;
 461
 462         ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
 463
 464         /* We don't care about errors */
 465
 466         talloc_free(call);
 467 }
 468
 469 /*
 470   start listening on the given address
 471 */
 472 static NTSTATUS dns_add_socket(struct dns_server *dns,
 473                                const struct model_ops *model_ops,
 474                                const char *name,
 475                                const char *address,
 476                                uint16_t port)
 477 {
 478         struct dns_socket *dns_socket;
 479         struct dns_udp_socket *dns_udp_socket;
 480         struct tevent_req *udpsubreq;
 481         NTSTATUS status;
 482         int ret;
 483
 484         dns_socket = talloc(dns, struct dns_socket);
 485         NT_STATUS_HAVE_NO_MEMORY(dns_socket);
 486
 487         dns_socket->dns = dns;
 488
 489         ret = tsocket_address_inet_from_strings(dns_socket, "ip",
 490                                                 address, port,
 491                                                 &dns_socket->local_address);
 492         if (ret != 0) {
 493                 status = map_nt_error_from_unix_common(errno);
 494                 return status;
 495         }
 496
 497         status = stream_setup_socket(dns->task,
 498                                      dns->task->event_ctx,
 499                                      dns->task->lp_ctx,
 500                                      model_ops,
 501                                      &dns_tcp_stream_ops,
 502                                      "ip", address, &port,
 503                                      lpcfg_socket_options(dns->task->lp_ctx),
 504                                      dns_socket);
 505         if (!NT_STATUS_IS_OK(status)) {
 506                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 507                          address, port, nt_errstr(status)));
 508                 talloc_free(dns_socket);
 509                 return status;
 510         }
 511
 512         dns_udp_socket = talloc(dns_socket, struct dns_udp_socket);
 513         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket);
 514
 515         dns_udp_socket->dns_socket = dns_socket;
 516
 517         ret = tdgram_inet_udp_socket(dns_socket->local_address,
 518                                      NULL,
 519                                      dns_udp_socket,
 520                                      &dns_udp_socket->dgram);
 521         if (ret != 0) {
 522                 status = map_nt_error_from_unix_common(errno);
 523                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
 524                          address, port, nt_errstr(status)));
 525                 return status;
 526         }
 527
 528         dns_udp_socket->send_queue = tevent_queue_create(dns_udp_socket,
 529                                                          "dns_udp_send_queue");
 530         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket->send_queue);
 531
 532         udpsubreq = tdgram_recvfrom_send(dns_udp_socket,
 533                                          dns->task->event_ctx,
 534                                          dns_udp_socket->dgram);
 535         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
 536         tevent_req_set_callback(udpsubreq, dns_udp_call_loop, dns_udp_socket);
 537
 538         return NT_STATUS_OK;
 539 }
 540
 541 /*
 542   setup our listening sockets on the configured network interfaces
 543 */
 544 static NTSTATUS dns_startup_interfaces(struct dns_server *dns, struct loadparm_context *lp_ctx,
 545                                        struct interface *ifaces)
 546 {
 547         const struct model_ops *model_ops;
 548         int num_interfaces;
 549         TALLOC_CTX *tmp_ctx = talloc_new(dns);
 550         NTSTATUS status;
 551         int i;
 552
 553         /* within the dns task we want to be a single process, so
 554            ask for the single process model ops and pass these to the
 555            stream_setup_socket() call. */
 556         model_ops = process_model_startup("single");
 557         if (!model_ops) {
 558                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 559                 return NT_STATUS_INTERNAL_ERROR;
 560         }
 561
 562         num_interfaces = iface_list_count(ifaces);
 563
 564         for (i=0; i<num_interfaces; i++) {
 565                 const char *address = talloc_strdup(tmp_ctx, iface_list_n_ip(ifaces, i));
 566
 567                 status = dns_add_socket(dns, model_ops, "dns", address, DNS_SERVICE_PORT);
 568                 NT_STATUS_NOT_OK_RETURN(status);
 569         }
 570
 571         talloc_free(tmp_ctx);
 572
 573         return NT_STATUS_OK;
 574 }
 575
 576 static int dns_server_sort_zones(struct ldb_message **m1, struct ldb_message **m2)
 577 {
 578         const char *n1, *n2;
 579         size_t l1, l2;
 580
 581         n1 = ldb_msg_find_attr_as_string(*m1, "name", NULL);
 582         n2 = ldb_msg_find_attr_as_string(*m2, "name", NULL);
 583
 584         l1 = strlen(n1);
 585         l2 = strlen(n2);
 586
 587         /* If the string lengths are not equal just sort by length */
 588         if (l1 != l2) {
 589                 /* If m1 is the larger zone name, return it first */
 590                 return l2 - l1;
 591         }
 592
 593         /*TODO: We need to compare DNs here, we want the DomainDNSZones first */
 594         return 0;
 595 }
 596
 597 static void dns_task_init(struct task_server *task)
 598 {
 599         struct dns_server *dns;
 600         NTSTATUS status;
 601         struct interface *ifaces;
 602         int ret;
 603         struct ldb_result *res;
 604         static const char * const attrs[] = { "name", NULL};
 605         unsigned int i;
 606
 607         switch (lpcfg_server_role(task->lp_ctx)) {
 608         case ROLE_STANDALONE:
 609                 task_server_terminate(task, "dns: no DNS required in standalone configuration", false);
 610                 return;
 611         case ROLE_DOMAIN_MEMBER:
 612                 task_server_terminate(task, "dns: no DNS required in member server configuration", false);
 613                 return;
 614         case ROLE_DOMAIN_CONTROLLER:
 615                 /* Yes, we want a DNS */
 616                 break;
 617         }
 618
 619         load_interface_list(task, task->lp_ctx, &ifaces);
 620
 621         if (iface_list_count(ifaces) == 0) {
 622                 task_server_terminate(task, "dns: no network interfaces configured", false);
 623                 return;
 624         }
 625
 626         task_server_set_title(task, "task[dns]");
 627
 628         dns = talloc_zero(task, struct dns_server);
 629         if (dns == NULL) {
 630                 task_server_terminate(task, "dns: out of memory", true);
 631                 return;
 632         }
 633
 634         dns->task = task;
 635
 636         dns->samdb = samdb_connect(dns, dns->task->event_ctx, dns->task->lp_ctx,
 637                               system_session(dns->task->lp_ctx), 0);
 638         if (!dns->samdb) {
 639                 task_server_terminate(task, "dns: samdb_connect failed", true);
 640                 return;
 641         }
 642
 643         // TODO: this search does not work against windows
 644         ret = dsdb_search(dns->samdb, dns, &res, NULL, LDB_SCOPE_SUBTREE,
 645                           attrs, DSDB_SEARCH_SEARCH_ALL_PARTITIONS, "(objectClass=dnsZone)");
 646         if (ret != LDB_SUCCESS) {
 647                 task_server_terminate(task,
 648                                       "dns: failed to look up root DNS zones",
 649                                       true);
 650                 return;
 651         }
 652
 653         TYPESAFE_QSORT(res->msgs, res->count, dns_server_sort_zones);
 654
 655         for (i=0; i < res->count; i++) {
 656                 struct dns_server_zone *z;
 657
 658                 z = talloc_zero(dns, struct dns_server_zone);
 659                 if (z == NULL) {
 660                 }
 661
 662                 z->name = ldb_msg_find_attr_as_string(res->msgs[i], "name", NULL);
 663                 z->dn = talloc_move(z, &res->msgs[i]->dn);
 664
 665                 DLIST_ADD_END(dns->zones, z, NULL);
 666         }
 667
 668         status = dns_startup_interfaces(dns, task->lp_ctx, ifaces);
 669         if (!NT_STATUS_IS_OK(status)) {
 670                 task_server_terminate(task, "dns failed to setup interfaces", true);
 671                 return;
 672         }
 673 }
 674
 675 NTSTATUS server_service_dns_init(void)
 676 {
 677         return register_server_service("dns", dns_task_init);
 678 }