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