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         uint16_t dns_err = DNS_RCODE_OK;
 104         struct dns_request_state *state;
 105         struct dns_name_packet *in_packet;
 106         struct dns_name_packet *out_packet;
 107         struct dns_res_rec *answers = NULL, *nsrecs = NULL, *additional = NULL;
 108         uint16_t num_answers = 0 , num_nsrecs = 0, num_additional = 0;
 109
 110         if (in->length < 12) {
 111                 return NT_STATUS_INVALID_PARAMETER;
 112         }
 113
 114         state = talloc_zero(mem_ctx, struct dns_request_state);
 115
 116         in_packet = talloc_zero(state, struct dns_name_packet);
 117         /* TODO: We don't really need an out_packet. */
 118         out_packet = talloc_zero(state, struct dns_name_packet);
 119
 120         if ((state == NULL) || (in_packet == NULL) || (out_packet == NULL)) {
 121                 TALLOC_FREE(state);
 122                 return NT_STATUS_NO_MEMORY;
 123         }
 124
 125         dump_data(8, in->data, in->length);
 126
 127         ndr_err = ndr_pull_struct_blob(in, in_packet, in_packet,
 128                         (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 129         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 130                 TALLOC_FREE(in_packet);
 131                 DEBUG(0, ("Failed to parse packet %d!\n", ndr_err));
 132                 dns_err = DNS_RCODE_FORMERR;
 133                 goto drop;
 134         }
 135         if (DEBUGLVL(8)) {
 136                 NDR_PRINT_DEBUG(dns_name_packet, in_packet);
 137         }
 138         *out_packet = *in_packet;
 139         state->flags |= in_packet->operation | DNS_FLAG_REPLY;
 140
 141         if (lpcfg_dns_recursive_queries(dns->task->lp_ctx)) {
 142                 state->flags |= DNS_FLAG_RECURSION_AVAIL;
 143         }
 144
 145         switch (in_packet->operation & DNS_OPCODE) {
 146         case DNS_OPCODE_QUERY:
 147
 148                 ret = dns_server_process_query(dns, state,
 149                                                out_packet, in_packet,
 150                                                &answers, &num_answers,
 151                                                &nsrecs,  &num_nsrecs,
 152                                                &additional, &num_additional);
 153
 154                 break;
 155         case DNS_OPCODE_UPDATE:
 156                 ret = dns_server_process_update(dns, state,
 157                                                 out_packet, in_packet,
 158                                                 &answers, &num_answers,
 159                                                 &nsrecs,  &num_nsrecs,
 160                                                 &additional, &num_additional);
 161                 break;
 162         default:
 163                 ret = WERR_DNS_ERROR_RCODE_NOT_IMPLEMENTED;
 164                 break;
 165         }
 166
 167         if (W_ERROR_IS_OK(ret)) {
 168                 out_packet->ancount = num_answers;
 169                 out_packet->answers = answers;
 170
 171                 out_packet->nscount = num_nsrecs;
 172                 out_packet->nsrecs  = nsrecs;
 173
 174                 out_packet->arcount = num_additional;
 175                 out_packet->additional = additional;
 176         } else {
 177                 out_packet->operation |= werr_to_dns_err(ret);
 178         }
 179
 180         out_packet->operation |= state->flags;
 181
 182         if (DEBUGLVL(8)) {
 183                 NDR_PRINT_DEBUG(dns_name_packet, out_packet);
 184         }
 185         ndr_err = ndr_push_struct_blob(out, out_packet, out_packet,
 186                         (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 187         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 188                 TALLOC_FREE(in_packet);
 189                 TALLOC_FREE(out_packet);
 190                 DEBUG(0, ("Failed to push packet %d!\n", ndr_err));
 191                 dns_err = DNS_RCODE_SERVFAIL;
 192                 goto drop;
 193         }
 194
 195         dump_data(8, out->data, out->length);
 196         return NT_STATUS_OK;
 197
 198 drop:
 199         *out = *in;
 200         out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
 201         out->data[3] |= dns_err;
 202         return NT_STATUS_OK;
 203 }
 204
 205 struct dns_tcp_call {
 206         struct dns_tcp_connection *dns_conn;
 207         DATA_BLOB in;
 208         DATA_BLOB out;
 209         uint8_t out_hdr[4];
 210         struct iovec out_iov[2];
 211 };
 212
 213 static void dns_tcp_call_writev_done(struct tevent_req *subreq);
 214
 215 static void dns_tcp_call_loop(struct tevent_req *subreq)
 216 {
 217         struct dns_tcp_connection *dns_conn = tevent_req_callback_data(subreq,
 218                                       struct dns_tcp_connection);
 219         struct dns_tcp_call *call;
 220         NTSTATUS status;
 221
 222         call = talloc(dns_conn, struct dns_tcp_call);
 223         if (call == NULL) {
 224                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 225                                 "no memory for dns_tcp_call");
 226                 return;
 227         }
 228         call->dns_conn = dns_conn;
 229
 230         status = tstream_read_pdu_blob_recv(subreq,
 231                                             call,
 232                                             &call->in);
 233         TALLOC_FREE(subreq);
 234         if (!NT_STATUS_IS_OK(status)) {
 235                 const char *reason;
 236
 237                 reason = talloc_asprintf(call, "dns_tcp_call_loop: "
 238                                          "tstream_read_pdu_blob_recv() - %s",
 239                                          nt_errstr(status));
 240                 if (!reason) {
 241                         reason = nt_errstr(status);
 242                 }
 243
 244                 dns_tcp_terminate_connection(dns_conn, reason);
 245                 return;
 246         }
 247
 248         DEBUG(10,("Received DNS TCP packet of length %lu from %s\n",
 249                  (long) call->in.length,
 250                  tsocket_address_string(dns_conn->conn->remote_address, call)));
 251
 252         /* skip length header */
 253         call->in.data += 2;
 254         call->in.length -= 2;
 255
 256         /* Call dns */
 257         status = dns_process(dns_conn->dns_socket->dns, call, &call->in, &call->out);
 258         if (!NT_STATUS_IS_OK(status)) {
 259                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 260                 dns_tcp_terminate_connection(dns_conn,
 261                                 "dns_tcp_call_loop: process function failed");
 262                 return;
 263         }
 264
 265         /* First add the length of the out buffer */
 266         RSSVAL(call->out_hdr, 0, call->out.length);
 267         call->out_iov[0].iov_base = (char *) call->out_hdr;
 268         call->out_iov[0].iov_len = 2;
 269
 270         call->out_iov[1].iov_base = (char *) call->out.data;
 271         call->out_iov[1].iov_len = call->out.length;
 272
 273         subreq = tstream_writev_queue_send(call,
 274                                            dns_conn->conn->event.ctx,
 275                                            dns_conn->tstream,
 276                                            dns_conn->send_queue,
 277                                            call->out_iov, 2);
 278         if (subreq == NULL) {
 279                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 280                                 "no memory for tstream_writev_queue_send");
 281                 return;
 282         }
 283         tevent_req_set_callback(subreq, dns_tcp_call_writev_done, call);
 284
 285         /*
 286          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
 287          * packet_full_request_u16 provides the pdu length then.
 288          */
 289         subreq = tstream_read_pdu_blob_send(dns_conn,
 290                                             dns_conn->conn->event.ctx,
 291                                             dns_conn->tstream,
 292                                             2, /* initial_read_size */
 293                                             packet_full_request_u16,
 294                                             dns_conn);
 295         if (subreq == NULL) {
 296                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 297                                 "no memory for tstream_read_pdu_blob_send");
 298                 return;
 299         }
 300         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 301 }
 302
 303 static void dns_tcp_call_writev_done(struct tevent_req *subreq)
 304 {
 305         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
 306                         struct dns_tcp_call);
 307         int sys_errno;
 308         int rc;
 309
 310         rc = tstream_writev_queue_recv(subreq, &sys_errno);
 311         TALLOC_FREE(subreq);
 312         if (rc == -1) {
 313                 const char *reason;
 314
 315                 reason = talloc_asprintf(call, "dns_tcp_call_writev_done: "
 316                                          "tstream_writev_queue_recv() - %d:%s",
 317                                          sys_errno, strerror(sys_errno));
 318                 if (!reason) {
 319                         reason = "dns_tcp_call_writev_done: tstream_writev_queue_recv() failed";
 320                 }
 321
 322                 dns_tcp_terminate_connection(call->dns_conn, reason);
 323                 return;
 324         }
 325
 326         /* We don't care about errors */
 327
 328         talloc_free(call);
 329 }
 330
 331 /*
 332   called when we get a new connection
 333 */
 334 static void dns_tcp_accept(struct stream_connection *conn)
 335 {
 336         struct dns_socket *dns_socket;
 337         struct dns_tcp_connection *dns_conn;
 338         struct tevent_req *subreq;
 339         int rc;
 340
 341         dns_conn = talloc_zero(conn, struct dns_tcp_connection);
 342         if (dns_conn == NULL) {
 343                 stream_terminate_connection(conn,
 344                                 "dns_tcp_accept: out of memory");
 345                 return;
 346         }
 347
 348         dns_conn->send_queue = tevent_queue_create(conn, "dns_tcp_accept");
 349         if (dns_conn->send_queue == NULL) {
 350                 stream_terminate_connection(conn,
 351                                 "dns_tcp_accept: out of memory");
 352                 return;
 353         }
 354
 355         dns_socket = talloc_get_type(conn->private_data, struct dns_socket);
 356
 357         TALLOC_FREE(conn->event.fde);
 358
 359         rc = tstream_bsd_existing_socket(dns_conn,
 360                         socket_get_fd(conn->socket),
 361                         &dns_conn->tstream);
 362         if (rc < 0) {
 363                 stream_terminate_connection(conn,
 364                                 "dns_tcp_accept: out of memory");
 365                 return;
 366         }
 367
 368         dns_conn->conn = conn;
 369         dns_conn->dns_socket = dns_socket;
 370         conn->private_data = dns_conn;
 371
 372         /*
 373          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
 374          * packet_full_request_u16 provides the pdu length then.
 375          */
 376         subreq = tstream_read_pdu_blob_send(dns_conn,
 377                                             dns_conn->conn->event.ctx,
 378                                             dns_conn->tstream,
 379                                             2, /* initial_read_size */
 380                                             packet_full_request_u16,
 381                                             dns_conn);
 382         if (subreq == NULL) {
 383                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_accept: "
 384                                 "no memory for tstream_read_pdu_blob_send");
 385                 return;
 386         }
 387         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 388 }
 389
 390 static const struct stream_server_ops dns_tcp_stream_ops = {
 391         .name                   = "dns_tcp",
 392         .accept_connection      = dns_tcp_accept,
 393         .recv_handler           = dns_tcp_recv,
 394         .send_handler           = dns_tcp_send
 395 };
 396
 397 struct dns_udp_call {
 398         struct tsocket_address *src;
 399         DATA_BLOB in;
 400         DATA_BLOB out;
 401 };
 402
 403 static void dns_udp_call_sendto_done(struct tevent_req *subreq);
 404
 405 static void dns_udp_call_loop(struct tevent_req *subreq)
 406 {
 407         struct dns_udp_socket *sock = tevent_req_callback_data(subreq,
 408                                       struct dns_udp_socket);
 409         struct dns_udp_call *call;
 410         uint8_t *buf;
 411         ssize_t len;
 412         int sys_errno;
 413         NTSTATUS status;
 414
 415         call = talloc(sock, struct dns_udp_call);
 416         if (call == NULL) {
 417                 talloc_free(call);
 418                 goto done;
 419         }
 420
 421         len = tdgram_recvfrom_recv(subreq, &sys_errno,
 422                                    call, &buf, &call->src);
 423         TALLOC_FREE(subreq);
 424         if (len == -1) {
 425                 talloc_free(call);
 426                 goto done;
 427         }
 428
 429         call->in.data = buf;
 430         call->in.length = len;
 431
 432         DEBUG(10,("Received DNS UDP packet of length %lu from %s\n",
 433                  (long)call->in.length,
 434                  tsocket_address_string(call->src, call)));
 435
 436         /* Call dns_process */
 437         status = dns_process(sock->dns_socket->dns, call, &call->in, &call->out);
 438         if (!NT_STATUS_IS_OK(status)) {
 439                 talloc_free(call);
 440                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 441                 goto done;
 442         }
 443
 444         subreq = tdgram_sendto_queue_send(call,
 445                                           sock->dns_socket->dns->task->event_ctx,
 446                                           sock->dgram,
 447                                           sock->send_queue,
 448                                           call->out.data,
 449                                           call->out.length,
 450                                           call->src);
 451         if (subreq == NULL) {
 452                 talloc_free(call);
 453                 goto done;
 454         }
 455         tevent_req_set_callback(subreq, dns_udp_call_sendto_done, call);
 456
 457 done:
 458         subreq = tdgram_recvfrom_send(sock,
 459                                       sock->dns_socket->dns->task->event_ctx,
 460                                       sock->dgram);
 461         if (subreq == NULL) {
 462                 task_server_terminate(sock->dns_socket->dns->task,
 463                                       "no memory for tdgram_recvfrom_send",
 464                                       true);
 465                 return;
 466         }
 467         tevent_req_set_callback(subreq, dns_udp_call_loop, sock);
 468 }
 469
 470 static void dns_udp_call_sendto_done(struct tevent_req *subreq)
 471 {
 472         struct dns_udp_call *call = tevent_req_callback_data(subreq,
 473                                        struct dns_udp_call);
 474         ssize_t ret;
 475         int sys_errno;
 476
 477         ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
 478
 479         /* We don't care about errors */
 480
 481         talloc_free(call);
 482 }
 483
 484 /*
 485   start listening on the given address
 486 */
 487 static NTSTATUS dns_add_socket(struct dns_server *dns,
 488                                const struct model_ops *model_ops,
 489                                const char *name,
 490                                const char *address,
 491                                uint16_t port)
 492 {
 493         struct dns_socket *dns_socket;
 494         struct dns_udp_socket *dns_udp_socket;
 495         struct tevent_req *udpsubreq;
 496         NTSTATUS status;
 497         int ret;
 498
 499         dns_socket = talloc(dns, struct dns_socket);
 500         NT_STATUS_HAVE_NO_MEMORY(dns_socket);
 501
 502         dns_socket->dns = dns;
 503
 504         ret = tsocket_address_inet_from_strings(dns_socket, "ip",
 505                                                 address, port,
 506                                                 &dns_socket->local_address);
 507         if (ret != 0) {
 508                 status = map_nt_error_from_unix_common(errno);
 509                 return status;
 510         }
 511
 512         status = stream_setup_socket(dns->task,
 513                                      dns->task->event_ctx,
 514                                      dns->task->lp_ctx,
 515                                      model_ops,
 516                                      &dns_tcp_stream_ops,
 517                                      "ip", address, &port,
 518                                      lpcfg_socket_options(dns->task->lp_ctx),
 519                                      dns_socket);
 520         if (!NT_STATUS_IS_OK(status)) {
 521                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 522                          address, port, nt_errstr(status)));
 523                 talloc_free(dns_socket);
 524                 return status;
 525         }
 526
 527         dns_udp_socket = talloc(dns_socket, struct dns_udp_socket);
 528         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket);
 529
 530         dns_udp_socket->dns_socket = dns_socket;
 531
 532         ret = tdgram_inet_udp_socket(dns_socket->local_address,
 533                                      NULL,
 534                                      dns_udp_socket,
 535                                      &dns_udp_socket->dgram);
 536         if (ret != 0) {
 537                 status = map_nt_error_from_unix_common(errno);
 538                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
 539                          address, port, nt_errstr(status)));
 540                 return status;
 541         }
 542
 543         dns_udp_socket->send_queue = tevent_queue_create(dns_udp_socket,
 544                                                          "dns_udp_send_queue");
 545         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket->send_queue);
 546
 547         udpsubreq = tdgram_recvfrom_send(dns_udp_socket,
 548                                          dns->task->event_ctx,
 549                                          dns_udp_socket->dgram);
 550         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
 551         tevent_req_set_callback(udpsubreq, dns_udp_call_loop, dns_udp_socket);
 552
 553         return NT_STATUS_OK;
 554 }
 555
 556 /*
 557   setup our listening sockets on the configured network interfaces
 558 */
 559 static NTSTATUS dns_startup_interfaces(struct dns_server *dns, struct loadparm_context *lp_ctx,
 560                                        struct interface *ifaces)
 561 {
 562         const struct model_ops *model_ops;
 563         int num_interfaces;
 564         TALLOC_CTX *tmp_ctx = talloc_new(dns);
 565         NTSTATUS status;
 566         int i;
 567
 568         /* within the dns task we want to be a single process, so
 569            ask for the single process model ops and pass these to the
 570            stream_setup_socket() call. */
 571         model_ops = process_model_startup("single");
 572         if (!model_ops) {
 573                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 574                 return NT_STATUS_INTERNAL_ERROR;
 575         }
 576
 577         num_interfaces = iface_list_count(ifaces);
 578
 579         for (i=0; i<num_interfaces; i++) {
 580                 const char *address = talloc_strdup(tmp_ctx, iface_list_n_ip(ifaces, i));
 581
 582                 status = dns_add_socket(dns, model_ops, "dns", address, DNS_SERVICE_PORT);
 583                 NT_STATUS_NOT_OK_RETURN(status);
 584         }
 585
 586         talloc_free(tmp_ctx);
 587
 588         return NT_STATUS_OK;
 589 }
 590
 591 static int dns_server_sort_zones(struct ldb_message **m1, struct ldb_message **m2)
 592 {
 593         const char *n1, *n2;
 594         size_t l1, l2;
 595
 596         n1 = ldb_msg_find_attr_as_string(*m1, "name", NULL);
 597         n2 = ldb_msg_find_attr_as_string(*m2, "name", NULL);
 598
 599         l1 = strlen(n1);
 600         l2 = strlen(n2);
 601
 602         /* If the string lengths are not equal just sort by length */
 603         if (l1 != l2) {
 604                 /* If m1 is the larger zone name, return it first */
 605                 return l2 - l1;
 606         }
 607
 608         /*TODO: We need to compare DNs here, we want the DomainDNSZones first */
 609         return 0;
 610 }
 611
 612 static void dns_task_init(struct task_server *task)
 613 {
 614         struct dns_server *dns;
 615         NTSTATUS status;
 616         struct interface *ifaces;
 617         int ret;
 618         struct ldb_result *res;
 619         static const char * const attrs[] = { "name", NULL};
 620         unsigned int i;
 621
 622         switch (lpcfg_server_role(task->lp_ctx)) {
 623         case ROLE_STANDALONE:
 624                 task_server_terminate(task, "dns: no DNS required in standalone configuration", false);
 625                 return;
 626         case ROLE_DOMAIN_MEMBER:
 627                 task_server_terminate(task, "dns: no DNS required in member server configuration", false);
 628                 return;
 629         case ROLE_DOMAIN_CONTROLLER:
 630                 /* Yes, we want a DNS */
 631                 break;
 632         }
 633
 634         load_interface_list(task, task->lp_ctx, &ifaces);
 635
 636         if (iface_list_count(ifaces) == 0) {
 637                 task_server_terminate(task, "dns: no network interfaces configured", false);
 638                 return;
 639         }
 640
 641         task_server_set_title(task, "task[dns]");
 642
 643         dns = talloc_zero(task, struct dns_server);
 644         if (dns == NULL) {
 645                 task_server_terminate(task, "dns: out of memory", true);
 646                 return;
 647         }
 648
 649         dns->task = task;
 650
 651         dns->samdb = samdb_connect(dns, dns->task->event_ctx, dns->task->lp_ctx,
 652                               system_session(dns->task->lp_ctx), 0);
 653         if (!dns->samdb) {
 654                 task_server_terminate(task, "dns: samdb_connect failed", true);
 655                 return;
 656         }
 657
 658         // TODO: this search does not work against windows
 659         ret = dsdb_search(dns->samdb, dns, &res, NULL, LDB_SCOPE_SUBTREE,
 660                           attrs, DSDB_SEARCH_SEARCH_ALL_PARTITIONS, "(objectClass=dnsZone)");
 661         if (ret != LDB_SUCCESS) {
 662                 task_server_terminate(task,
 663                                       "dns: failed to look up root DNS zones",
 664                                       true);
 665                 return;
 666         }
 667
 668         TYPESAFE_QSORT(res->msgs, res->count, dns_server_sort_zones);
 669
 670         for (i=0; i < res->count; i++) {
 671                 struct dns_server_zone *z;
 672
 673                 z = talloc_zero(dns, struct dns_server_zone);
 674                 if (z == NULL) {
 675                 }
 676
 677                 z->name = ldb_msg_find_attr_as_string(res->msgs[i], "name", NULL);
 678                 z->dn = talloc_move(z, &res->msgs[i]->dn);
 679
 680                 DLIST_ADD_END(dns->zones, z, NULL);
 681         }
 682
 683         status = dns_startup_interfaces(dns, task->lp_ctx, ifaces);
 684         if (!NT_STATUS_IS_OK(status)) {
 685                 task_server_terminate(task, "dns failed to setup interfaces", true);
 686                 return;
 687         }
 688 }
 689
 690 NTSTATUS server_service_dns_init(void)
 691 {
 692         return register_server_service("dns", dns_task_init);
 693 }