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 #include "lib/util/tevent_werror.h"
  46 #include "auth/auth.h"
  47 #include "auth/credentials/credentials.h"
  48
  49 NTSTATUS server_service_dns_init(void);
  50
  51 /* hold information about one dns socket */
  52 struct dns_socket {
  53         struct dns_server *dns;
  54         struct tsocket_address *local_address;
  55 };
  56
  57 struct dns_udp_socket {
  58         struct dns_socket *dns_socket;
  59         struct tdgram_context *dgram;
  60         struct tevent_queue *send_queue;
  61 };
  62
  63 /*
  64   state of an open tcp connection
  65 */
  66 struct dns_tcp_connection {
  67         /* stream connection we belong to */
  68         struct stream_connection *conn;
  69
  70         /* the dns_server the connection belongs to */
  71         struct dns_socket *dns_socket;
  72
  73         struct tstream_context *tstream;
  74
  75         struct tevent_queue *send_queue;
  76 };
  77
  78 static void dns_tcp_terminate_connection(struct dns_tcp_connection *dnsconn, const char *reason)
  79 {
  80         stream_terminate_connection(dnsconn->conn, reason);
  81 }
  82
  83 static void dns_tcp_recv(struct stream_connection *conn, uint16_t flags)
  84 {
  85         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
  86                                                              struct dns_tcp_connection);
  87         /* this should never be triggered! */
  88         dns_tcp_terminate_connection(dnsconn, "dns_tcp_recv: called");
  89 }
  90
  91 static void dns_tcp_send(struct stream_connection *conn, uint16_t flags)
  92 {
  93         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
  94                                                              struct dns_tcp_connection);
  95         /* this should never be triggered! */
  96         dns_tcp_terminate_connection(dnsconn, "dns_tcp_send: called");
  97 }
  98
  99 struct dns_process_state {
 100         DATA_BLOB *in;
 101         struct dns_name_packet in_packet;
 102         struct dns_request_state state;
 103         uint16_t dns_err;
 104         struct dns_name_packet out_packet;
 105         DATA_BLOB out;
 106 };
 107
 108 static void dns_process_done(struct tevent_req *subreq);
 109
 110 static struct tevent_req *dns_process_send(TALLOC_CTX *mem_ctx,
 111                                            struct tevent_context *ev,
 112                                            struct dns_server *dns,
 113                                            DATA_BLOB *in)
 114 {
 115         struct tevent_req *req, *subreq;
 116         struct dns_process_state *state;
 117         enum ndr_err_code ndr_err;
 118         WERROR ret;
 119
 120         req = tevent_req_create(mem_ctx, &state, struct dns_process_state);
 121         if (req == NULL) {
 122                 return NULL;
 123         }
 124         state->in = in;
 125
 126         if (in->length < 12) {
 127                 tevent_req_werror(req, WERR_INVALID_PARAM);
 128                 return tevent_req_post(req, ev);
 129         }
 130         dump_data(8, in->data, in->length);
 131
 132         ndr_err = ndr_pull_struct_blob(
 133                 in, state, &state->in_packet,
 134                 (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 135
 136         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 137                 state->dns_err = DNS_RCODE_FORMERR;
 138                 tevent_req_done(req);
 139                 return tevent_req_post(req, ev);
 140         }
 141         if (DEBUGLVL(8)) {
 142                 NDR_PRINT_DEBUG(dns_name_packet, &state->in_packet);
 143         }
 144
 145         state->state.flags = state->in_packet.operation;
 146         state->state.flags |= DNS_FLAG_REPLY;
 147
 148         if (lpcfg_dns_recursive_queries(dns->task->lp_ctx)) {
 149                 state->state.flags |= DNS_FLAG_RECURSION_AVAIL;
 150         }
 151
 152         state->out_packet = state->in_packet;
 153
 154         switch (state->in_packet.operation & DNS_OPCODE) {
 155         case DNS_OPCODE_QUERY:
 156                 subreq = dns_server_process_query_send(
 157                         state, ev, dns, &state->state, &state->in_packet);
 158                 if (tevent_req_nomem(subreq, req)) {
 159                         return tevent_req_post(req, ev);
 160                 }
 161                 tevent_req_set_callback(subreq, dns_process_done, req);
 162                 return req;
 163         case DNS_OPCODE_UPDATE:
 164                 ret = dns_server_process_update(
 165                         dns, &state->state, state, &state->in_packet,
 166                         &state->out_packet.answers, &state->out_packet.ancount,
 167                         &state->out_packet.nsrecs,  &state->out_packet.nscount,
 168                         &state->out_packet.additional,
 169                         &state->out_packet.arcount);
 170                 break;
 171         default:
 172                 ret = WERR_DNS_ERROR_RCODE_NOT_IMPLEMENTED;
 173         }
 174         if (!W_ERROR_IS_OK(ret)) {
 175                 state->dns_err = werr_to_dns_err(ret);
 176         }
 177         tevent_req_done(req);
 178         return tevent_req_post(req, ev);
 179 }
 180
 181 static void dns_process_done(struct tevent_req *subreq)
 182 {
 183         struct tevent_req *req = tevent_req_callback_data(
 184                 subreq, struct tevent_req);
 185         struct dns_process_state *state = tevent_req_data(
 186                 req, struct dns_process_state);
 187         WERROR ret;
 188
 189         ret = dns_server_process_query_recv(
 190                 subreq, state,
 191                 &state->out_packet.answers, &state->out_packet.ancount,
 192                 &state->out_packet.nsrecs,  &state->out_packet.nscount,
 193                 &state->out_packet.additional, &state->out_packet.arcount);
 194         TALLOC_FREE(subreq);
 195
 196         if (!W_ERROR_IS_OK(ret)) {
 197                 state->dns_err = werr_to_dns_err(ret);
 198         }
 199         tevent_req_done(req);
 200 }
 201
 202 static WERROR dns_process_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 203                                DATA_BLOB *out)
 204 {
 205         struct dns_process_state *state = tevent_req_data(
 206                 req, struct dns_process_state);
 207         enum ndr_err_code ndr_err;
 208         WERROR ret;
 209
 210         if (tevent_req_is_werror(req, &ret)) {
 211                 return ret;
 212         }
 213         if (state->dns_err != DNS_RCODE_OK) {
 214                 goto drop;
 215         }
 216         state->out_packet.operation |= state->state.flags;
 217
 218         ndr_err = ndr_push_struct_blob(
 219                 out, mem_ctx, &state->out_packet,
 220                 (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 221         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 222                 DEBUG(1, ("Failed to push packet: %s!\n",
 223                           ndr_errstr(ndr_err)));
 224                 state->dns_err = DNS_RCODE_SERVFAIL;
 225                 goto drop;
 226         }
 227         return WERR_OK;
 228
 229 drop:
 230         *out = data_blob_talloc(mem_ctx, state->in->data, state->in->length);
 231         if (out->data == NULL) {
 232                 return WERR_NOMEM;
 233         }
 234         out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
 235         out->data[3] |= state->dns_err;
 236         return WERR_OK;
 237 }
 238
 239 struct dns_tcp_call {
 240         struct dns_tcp_connection *dns_conn;
 241         DATA_BLOB in;
 242         DATA_BLOB out;
 243         uint8_t out_hdr[4];
 244         struct iovec out_iov[2];
 245 };
 246
 247 static void dns_tcp_call_process_done(struct tevent_req *subreq);
 248 static void dns_tcp_call_writev_done(struct tevent_req *subreq);
 249
 250 static void dns_tcp_call_loop(struct tevent_req *subreq)
 251 {
 252         struct dns_tcp_connection *dns_conn = tevent_req_callback_data(subreq,
 253                                       struct dns_tcp_connection);
 254         struct dns_server *dns = dns_conn->dns_socket->dns;
 255         struct dns_tcp_call *call;
 256         NTSTATUS status;
 257
 258         call = talloc(dns_conn, struct dns_tcp_call);
 259         if (call == NULL) {
 260                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 261                                 "no memory for dns_tcp_call");
 262                 return;
 263         }
 264         call->dns_conn = dns_conn;
 265
 266         status = tstream_read_pdu_blob_recv(subreq,
 267                                             call,
 268                                             &call->in);
 269         TALLOC_FREE(subreq);
 270         if (!NT_STATUS_IS_OK(status)) {
 271                 const char *reason;
 272
 273                 reason = talloc_asprintf(call, "dns_tcp_call_loop: "
 274                                          "tstream_read_pdu_blob_recv() - %s",
 275                                          nt_errstr(status));
 276                 if (!reason) {
 277                         reason = nt_errstr(status);
 278                 }
 279
 280                 dns_tcp_terminate_connection(dns_conn, reason);
 281                 return;
 282         }
 283
 284         DEBUG(10,("Received DNS TCP packet of length %lu from %s\n",
 285                  (long) call->in.length,
 286                  tsocket_address_string(dns_conn->conn->remote_address, call)));
 287
 288         /* skip length header */
 289         call->in.data += 2;
 290         call->in.length -= 2;
 291
 292         subreq = dns_process_send(call, dns->task->event_ctx, dns,
 293                                   &call->in);
 294         if (subreq == NULL) {
 295                 dns_tcp_terminate_connection(
 296                         dns_conn, "dns_tcp_call_loop: dns_process_send "
 297                         "failed\n");
 298                 return;
 299         }
 300         tevent_req_set_callback(subreq, dns_tcp_call_process_done, call);
 301
 302         /*
 303          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
 304          * packet_full_request_u16 provides the pdu length then.
 305          */
 306         subreq = tstream_read_pdu_blob_send(dns_conn,
 307                                             dns_conn->conn->event.ctx,
 308                                             dns_conn->tstream,
 309                                             2, /* initial_read_size */
 310                                             packet_full_request_u16,
 311                                             dns_conn);
 312         if (subreq == NULL) {
 313                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 314                                 "no memory for tstream_read_pdu_blob_send");
 315                 return;
 316         }
 317         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 318 }
 319
 320 static void dns_tcp_call_process_done(struct tevent_req *subreq)
 321 {
 322         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
 323                         struct dns_tcp_call);
 324         struct dns_tcp_connection *dns_conn = call->dns_conn;
 325         WERROR err;
 326
 327         err = dns_process_recv(subreq, call, &call->out);
 328         TALLOC_FREE(subreq);
 329         if (!W_ERROR_IS_OK(err)) {
 330                 DEBUG(1, ("dns_process returned %s\n", win_errstr(err)));
 331                 dns_tcp_terminate_connection(dns_conn,
 332                                 "dns_tcp_call_loop: process function failed");
 333                 return;
 334         }
 335
 336         /* First add the length of the out buffer */
 337         RSSVAL(call->out_hdr, 0, call->out.length);
 338         call->out_iov[0].iov_base = (char *) call->out_hdr;
 339         call->out_iov[0].iov_len = 2;
 340
 341         call->out_iov[1].iov_base = (char *) call->out.data;
 342         call->out_iov[1].iov_len = call->out.length;
 343
 344         subreq = tstream_writev_queue_send(call,
 345                                            dns_conn->conn->event.ctx,
 346                                            dns_conn->tstream,
 347                                            dns_conn->send_queue,
 348                                            call->out_iov, 2);
 349         if (subreq == NULL) {
 350                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 351                                 "no memory for tstream_writev_queue_send");
 352                 return;
 353         }
 354         tevent_req_set_callback(subreq, dns_tcp_call_writev_done, call);
 355 }
 356
 357 static void dns_tcp_call_writev_done(struct tevent_req *subreq)
 358 {
 359         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
 360                         struct dns_tcp_call);
 361         int sys_errno;
 362         int rc;
 363
 364         rc = tstream_writev_queue_recv(subreq, &sys_errno);
 365         TALLOC_FREE(subreq);
 366         if (rc == -1) {
 367                 const char *reason;
 368
 369                 reason = talloc_asprintf(call, "dns_tcp_call_writev_done: "
 370                                          "tstream_writev_queue_recv() - %d:%s",
 371                                          sys_errno, strerror(sys_errno));
 372                 if (!reason) {
 373                         reason = "dns_tcp_call_writev_done: tstream_writev_queue_recv() failed";
 374                 }
 375
 376                 dns_tcp_terminate_connection(call->dns_conn, reason);
 377                 return;
 378         }
 379
 380         /* We don't care about errors */
 381
 382         talloc_free(call);
 383 }
 384
 385 /*
 386   called when we get a new connection
 387 */
 388 static void dns_tcp_accept(struct stream_connection *conn)
 389 {
 390         struct dns_socket *dns_socket;
 391         struct dns_tcp_connection *dns_conn;
 392         struct tevent_req *subreq;
 393         int rc;
 394
 395         dns_conn = talloc_zero(conn, struct dns_tcp_connection);
 396         if (dns_conn == NULL) {
 397                 stream_terminate_connection(conn,
 398                                 "dns_tcp_accept: out of memory");
 399                 return;
 400         }
 401
 402         dns_conn->send_queue = tevent_queue_create(conn, "dns_tcp_accept");
 403         if (dns_conn->send_queue == NULL) {
 404                 stream_terminate_connection(conn,
 405                                 "dns_tcp_accept: out of memory");
 406                 return;
 407         }
 408
 409         dns_socket = talloc_get_type(conn->private_data, struct dns_socket);
 410
 411         TALLOC_FREE(conn->event.fde);
 412
 413         rc = tstream_bsd_existing_socket(dns_conn,
 414                         socket_get_fd(conn->socket),
 415                         &dns_conn->tstream);
 416         if (rc < 0) {
 417                 stream_terminate_connection(conn,
 418                                 "dns_tcp_accept: out of memory");
 419                 return;
 420         }
 421
 422         dns_conn->conn = conn;
 423         dns_conn->dns_socket = dns_socket;
 424         conn->private_data = dns_conn;
 425
 426         /*
 427          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
 428          * packet_full_request_u16 provides the pdu length then.
 429          */
 430         subreq = tstream_read_pdu_blob_send(dns_conn,
 431                                             dns_conn->conn->event.ctx,
 432                                             dns_conn->tstream,
 433                                             2, /* initial_read_size */
 434                                             packet_full_request_u16,
 435                                             dns_conn);
 436         if (subreq == NULL) {
 437                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_accept: "
 438                                 "no memory for tstream_read_pdu_blob_send");
 439                 return;
 440         }
 441         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 442 }
 443
 444 static const struct stream_server_ops dns_tcp_stream_ops = {
 445         .name                   = "dns_tcp",
 446         .accept_connection      = dns_tcp_accept,
 447         .recv_handler           = dns_tcp_recv,
 448         .send_handler           = dns_tcp_send
 449 };
 450
 451 struct dns_udp_call {
 452         struct dns_udp_socket *sock;
 453         struct tsocket_address *src;
 454         DATA_BLOB in;
 455         DATA_BLOB out;
 456 };
 457
 458 static void dns_udp_call_process_done(struct tevent_req *subreq);
 459 static void dns_udp_call_sendto_done(struct tevent_req *subreq);
 460
 461 static void dns_udp_call_loop(struct tevent_req *subreq)
 462 {
 463         struct dns_udp_socket *sock = tevent_req_callback_data(subreq,
 464                                       struct dns_udp_socket);
 465         struct dns_server *dns = sock->dns_socket->dns;
 466         struct dns_udp_call *call;
 467         uint8_t *buf;
 468         ssize_t len;
 469         int sys_errno;
 470
 471         call = talloc(sock, struct dns_udp_call);
 472         if (call == NULL) {
 473                 talloc_free(call);
 474                 goto done;
 475         }
 476         call->sock = sock;
 477
 478         len = tdgram_recvfrom_recv(subreq, &sys_errno,
 479                                    call, &buf, &call->src);
 480         TALLOC_FREE(subreq);
 481         if (len == -1) {
 482                 talloc_free(call);
 483                 goto done;
 484         }
 485
 486         call->in.data = buf;
 487         call->in.length = len;
 488
 489         DEBUG(10,("Received DNS UDP packet of length %lu from %s\n",
 490                  (long)call->in.length,
 491                  tsocket_address_string(call->src, call)));
 492
 493         subreq = dns_process_send(call, dns->task->event_ctx, dns,
 494                                   &call->in);
 495         if (subreq == NULL) {
 496                 TALLOC_FREE(call);
 497                 goto done;
 498         }
 499         tevent_req_set_callback(subreq, dns_udp_call_process_done, call);
 500
 501 done:
 502         subreq = tdgram_recvfrom_send(sock,
 503                                       sock->dns_socket->dns->task->event_ctx,
 504                                       sock->dgram);
 505         if (subreq == NULL) {
 506                 task_server_terminate(sock->dns_socket->dns->task,
 507                                       "no memory for tdgram_recvfrom_send",
 508                                       true);
 509                 return;
 510         }
 511         tevent_req_set_callback(subreq, dns_udp_call_loop, sock);
 512 }
 513
 514 static void dns_udp_call_process_done(struct tevent_req *subreq)
 515 {
 516         struct dns_udp_call *call = tevent_req_callback_data(
 517                 subreq, struct dns_udp_call);
 518         struct dns_udp_socket *sock = call->sock;
 519         struct dns_server *dns = sock->dns_socket->dns;
 520         WERROR err;
 521
 522         err = dns_process_recv(subreq, call, &call->out);
 523         TALLOC_FREE(subreq);
 524         if (!W_ERROR_IS_OK(err)) {
 525                 DEBUG(1, ("dns_process returned %s\n", win_errstr(err)));
 526                 TALLOC_FREE(call);
 527                 return;
 528         }
 529
 530         subreq = tdgram_sendto_queue_send(call,
 531                                           dns->task->event_ctx,
 532                                           sock->dgram,
 533                                           sock->send_queue,
 534                                           call->out.data,
 535                                           call->out.length,
 536                                           call->src);
 537         if (subreq == NULL) {
 538                 talloc_free(call);
 539                 return;
 540         }
 541         tevent_req_set_callback(subreq, dns_udp_call_sendto_done, call);
 542
 543 }
 544 static void dns_udp_call_sendto_done(struct tevent_req *subreq)
 545 {
 546         struct dns_udp_call *call = tevent_req_callback_data(subreq,
 547                                        struct dns_udp_call);
 548         ssize_t ret;
 549         int sys_errno;
 550
 551         ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
 552
 553         /* We don't care about errors */
 554
 555         talloc_free(call);
 556 }
 557
 558 /*
 559   start listening on the given address
 560 */
 561 static NTSTATUS dns_add_socket(struct dns_server *dns,
 562                                const struct model_ops *model_ops,
 563                                const char *name,
 564                                const char *address,
 565                                uint16_t port)
 566 {
 567         struct dns_socket *dns_socket;
 568         struct dns_udp_socket *dns_udp_socket;
 569         struct tevent_req *udpsubreq;
 570         NTSTATUS status;
 571         int ret;
 572
 573         dns_socket = talloc(dns, struct dns_socket);
 574         NT_STATUS_HAVE_NO_MEMORY(dns_socket);
 575
 576         dns_socket->dns = dns;
 577
 578         ret = tsocket_address_inet_from_strings(dns_socket, "ip",
 579                                                 address, port,
 580                                                 &dns_socket->local_address);
 581         if (ret != 0) {
 582                 status = map_nt_error_from_unix_common(errno);
 583                 return status;
 584         }
 585
 586         status = stream_setup_socket(dns->task,
 587                                      dns->task->event_ctx,
 588                                      dns->task->lp_ctx,
 589                                      model_ops,
 590                                      &dns_tcp_stream_ops,
 591                                      "ip", address, &port,
 592                                      lpcfg_socket_options(dns->task->lp_ctx),
 593                                      dns_socket);
 594         if (!NT_STATUS_IS_OK(status)) {
 595                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 596                          address, port, nt_errstr(status)));
 597                 talloc_free(dns_socket);
 598                 return status;
 599         }
 600
 601         dns_udp_socket = talloc(dns_socket, struct dns_udp_socket);
 602         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket);
 603
 604         dns_udp_socket->dns_socket = dns_socket;
 605
 606         ret = tdgram_inet_udp_socket(dns_socket->local_address,
 607                                      NULL,
 608                                      dns_udp_socket,
 609                                      &dns_udp_socket->dgram);
 610         if (ret != 0) {
 611                 status = map_nt_error_from_unix_common(errno);
 612                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
 613                          address, port, nt_errstr(status)));
 614                 return status;
 615         }
 616
 617         dns_udp_socket->send_queue = tevent_queue_create(dns_udp_socket,
 618                                                          "dns_udp_send_queue");
 619         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket->send_queue);
 620
 621         udpsubreq = tdgram_recvfrom_send(dns_udp_socket,
 622                                          dns->task->event_ctx,
 623                                          dns_udp_socket->dgram);
 624         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
 625         tevent_req_set_callback(udpsubreq, dns_udp_call_loop, dns_udp_socket);
 626
 627         return NT_STATUS_OK;
 628 }
 629
 630 /*
 631   setup our listening sockets on the configured network interfaces
 632 */
 633 static NTSTATUS dns_startup_interfaces(struct dns_server *dns, struct loadparm_context *lp_ctx,
 634                                        struct interface *ifaces)
 635 {
 636         const struct model_ops *model_ops;
 637         int num_interfaces;
 638         TALLOC_CTX *tmp_ctx = talloc_new(dns);
 639         NTSTATUS status;
 640         int i;
 641
 642         /* within the dns task we want to be a single process, so
 643            ask for the single process model ops and pass these to the
 644            stream_setup_socket() call. */
 645         model_ops = process_model_startup("single");
 646         if (!model_ops) {
 647                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 648                 return NT_STATUS_INTERNAL_ERROR;
 649         }
 650
 651         num_interfaces = iface_list_count(ifaces);
 652
 653         for (i=0; i<num_interfaces; i++) {
 654                 const char *address = talloc_strdup(tmp_ctx, iface_list_n_ip(ifaces, i));
 655
 656                 status = dns_add_socket(dns, model_ops, "dns", address, DNS_SERVICE_PORT);
 657                 NT_STATUS_NOT_OK_RETURN(status);
 658         }
 659
 660         talloc_free(tmp_ctx);
 661
 662         return NT_STATUS_OK;
 663 }
 664
 665 static int dns_server_sort_zones(struct ldb_message **m1, struct ldb_message **m2)
 666 {
 667         const char *n1, *n2;
 668         size_t l1, l2;
 669
 670         n1 = ldb_msg_find_attr_as_string(*m1, "name", NULL);
 671         n2 = ldb_msg_find_attr_as_string(*m2, "name", NULL);
 672
 673         l1 = strlen(n1);
 674         l2 = strlen(n2);
 675
 676         /* If the string lengths are not equal just sort by length */
 677         if (l1 != l2) {
 678                 /* If m1 is the larger zone name, return it first */
 679                 return l2 - l1;
 680         }
 681
 682         /*TODO: We need to compare DNs here, we want the DomainDNSZones first */
 683         return 0;
 684 }
 685
 686 static struct dns_server_tkey_store *tkey_store_init(TALLOC_CTX *mem_ctx,
 687                                                      uint16_t size)
 688 {
 689         struct dns_server_tkey_store *buffer = talloc_zero(mem_ctx,
 690                                                 struct dns_server_tkey_store);
 691
 692         if (buffer == NULL) {
 693                 return NULL;
 694         }
 695
 696         buffer->size = size;
 697         buffer->next_idx = 0;
 698
 699         buffer->tkeys = talloc_zero_array(buffer, struct dns_server_tkey *, size);
 700         if (buffer->tkeys == NULL) {
 701                 TALLOC_FREE(buffer);
 702         }
 703
 704         return buffer;
 705 }
 706
 707 static void dns_task_init(struct task_server *task)
 708 {
 709         struct dns_server *dns;
 710         NTSTATUS status;
 711         struct interface *ifaces;
 712         int ret;
 713         struct ldb_result *res;
 714         static const char * const attrs[] = { "name", NULL};
 715         unsigned int i;
 716
 717         switch (lpcfg_server_role(task->lp_ctx)) {
 718         case ROLE_STANDALONE:
 719                 task_server_terminate(task, "dns: no DNS required in standalone configuration", false);
 720                 return;
 721         case ROLE_DOMAIN_MEMBER:
 722                 task_server_terminate(task, "dns: no DNS required in member server configuration", false);
 723                 return;
 724         case ROLE_ACTIVE_DIRECTORY_DC:
 725                 /* Yes, we want a DNS */
 726                 break;
 727         }
 728
 729         load_interface_list(task, task->lp_ctx, &ifaces);
 730
 731         if (iface_list_count(ifaces) == 0) {
 732                 task_server_terminate(task, "dns: no network interfaces configured", false);
 733                 return;
 734         }
 735
 736         task_server_set_title(task, "task[dns]");
 737
 738         dns = talloc_zero(task, struct dns_server);
 739         if (dns == NULL) {
 740                 task_server_terminate(task, "dns: out of memory", true);
 741                 return;
 742         }
 743
 744         dns->task = task;
 745
 746         dns->server_credentials = cli_credentials_init(dns);
 747         if (!dns->server_credentials) {
 748                 task_server_terminate(task, "Failed to init server credentials\n", true);
 749                 return;
 750         }
 751
 752         cli_credentials_set_conf(dns->server_credentials, task->lp_ctx);
 753         status = cli_credentials_set_machine_account(dns->server_credentials, task->lp_ctx);
 754         if (!NT_STATUS_IS_OK(status)) {
 755                 task_server_terminate(task,
 756                         talloc_asprintf(task, "Failed to obtain server credentials, perhaps a standalone server?: %s\n",
 757                                         nt_errstr(status)),
 758                         true);
 759                 return;
 760         }
 761
 762         dns->tkeys = tkey_store_init(dns, TKEY_BUFFER_SIZE);
 763         if (!dns->tkeys) {
 764                 task_server_terminate(task, "Failed to allocate tkey storage\n", true);
 765                 return;
 766         }
 767
 768         dns->samdb = samdb_connect(dns, dns->task->event_ctx, dns->task->lp_ctx,
 769                               system_session(dns->task->lp_ctx), 0);
 770         if (!dns->samdb) {
 771                 task_server_terminate(task, "dns: samdb_connect failed", true);
 772                 return;
 773         }
 774
 775         // TODO: this search does not work against windows
 776         ret = dsdb_search(dns->samdb, dns, &res, NULL, LDB_SCOPE_SUBTREE,
 777                           attrs, DSDB_SEARCH_SEARCH_ALL_PARTITIONS, "(objectClass=dnsZone)");
 778         if (ret != LDB_SUCCESS) {
 779                 task_server_terminate(task,
 780                                       "dns: failed to look up root DNS zones",
 781                                       true);
 782                 return;
 783         }
 784
 785         TYPESAFE_QSORT(res->msgs, res->count, dns_server_sort_zones);
 786
 787         for (i=0; i < res->count; i++) {
 788                 struct dns_server_zone *z;
 789
 790                 z = talloc_zero(dns, struct dns_server_zone);
 791                 if (z == NULL) {
 792                 }
 793
 794                 z->name = ldb_msg_find_attr_as_string(res->msgs[i], "name", NULL);
 795                 z->dn = talloc_move(z, &res->msgs[i]->dn);
 796
 797                 DLIST_ADD_END(dns->zones, z, NULL);
 798         }
 799
 800         status = dns_startup_interfaces(dns, task->lp_ctx, ifaces);
 801         if (!NT_STATUS_IS_OK(status)) {
 802                 task_server_terminate(task, "dns failed to setup interfaces", true);
 803                 return;
 804         }
 805 }
 806
 807 NTSTATUS server_service_dns_init(void)
 808 {
 809         return register_server_service("dns", dns_task_init);
 810 }