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