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_server *dns;
 102         struct dns_name_packet in_packet;
 103         struct dns_request_state state;
 104         uint16_t dns_err;
 105         struct dns_name_packet out_packet;
 106         DATA_BLOB out;
 107 };
 108
 109 static void dns_process_done(struct tevent_req *subreq);
 110
 111 static struct tevent_req *dns_process_send(TALLOC_CTX *mem_ctx,
 112                                            struct tevent_context *ev,
 113                                            struct dns_server *dns,
 114                                            DATA_BLOB *in)
 115 {
 116         struct tevent_req *req, *subreq;
 117         struct dns_process_state *state;
 118         enum ndr_err_code ndr_err;
 119         WERROR ret;
 120
 121         req = tevent_req_create(mem_ctx, &state, struct dns_process_state);
 122         if (req == NULL) {
 123                 return NULL;
 124         }
 125         state->in = in;
 126
 127         state->dns = dns;
 128
 129         if (in->length < 12) {
 130                 tevent_req_werror(req, WERR_INVALID_PARAM);
 131                 return tevent_req_post(req, ev);
 132         }
 133         dump_data(8, in->data, in->length);
 134
 135         ndr_err = ndr_pull_struct_blob(
 136                 in, state, &state->in_packet,
 137                 (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 138
 139         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 140                 state->dns_err = DNS_RCODE_FORMERR;
 141                 tevent_req_done(req);
 142                 return tevent_req_post(req, ev);
 143         }
 144         if (DEBUGLVL(8)) {
 145                 NDR_PRINT_DEBUG(dns_name_packet, &state->in_packet);
 146         }
 147
 148         state->state.flags = state->in_packet.operation;
 149         state->state.flags |= DNS_FLAG_REPLY;
 150
 151         if (lpcfg_dns_recursive_queries(dns->task->lp_ctx)) {
 152                 state->state.flags |= DNS_FLAG_RECURSION_AVAIL;
 153         }
 154
 155         state->out_packet = state->in_packet;
 156
 157         switch (state->in_packet.operation & DNS_OPCODE) {
 158         case DNS_OPCODE_QUERY:
 159                 subreq = dns_server_process_query_send(
 160                         state, ev, dns, &state->state, &state->in_packet);
 161                 if (tevent_req_nomem(subreq, req)) {
 162                         return tevent_req_post(req, ev);
 163                 }
 164                 tevent_req_set_callback(subreq, dns_process_done, req);
 165                 return req;
 166         case DNS_OPCODE_UPDATE:
 167                 ret = dns_server_process_update(
 168                         dns, &state->state, state, &state->in_packet,
 169                         &state->out_packet.answers, &state->out_packet.ancount,
 170                         &state->out_packet.nsrecs,  &state->out_packet.nscount,
 171                         &state->out_packet.additional,
 172                         &state->out_packet.arcount);
 173                 break;
 174         default:
 175                 ret = WERR_DNS_ERROR_RCODE_NOT_IMPLEMENTED;
 176         }
 177         if (!W_ERROR_IS_OK(ret)) {
 178                 state->dns_err = werr_to_dns_err(ret);
 179         }
 180         tevent_req_done(req);
 181         return tevent_req_post(req, ev);
 182 }
 183
 184 static void dns_process_done(struct tevent_req *subreq)
 185 {
 186         struct tevent_req *req = tevent_req_callback_data(
 187                 subreq, struct tevent_req);
 188         struct dns_process_state *state = tevent_req_data(
 189                 req, struct dns_process_state);
 190         WERROR ret;
 191
 192         ret = dns_server_process_query_recv(
 193                 subreq, state,
 194                 &state->out_packet.answers, &state->out_packet.ancount,
 195                 &state->out_packet.nsrecs,  &state->out_packet.nscount,
 196                 &state->out_packet.additional, &state->out_packet.arcount);
 197         TALLOC_FREE(subreq);
 198
 199         if (!W_ERROR_IS_OK(ret)) {
 200                 state->dns_err = werr_to_dns_err(ret);
 201         }
 202         tevent_req_done(req);
 203 }
 204
 205 static WERROR dns_process_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 206                                DATA_BLOB *out)
 207 {
 208         struct dns_process_state *state = tevent_req_data(
 209                 req, struct dns_process_state);
 210         enum ndr_err_code ndr_err;
 211         WERROR ret;
 212
 213         if (tevent_req_is_werror(req, &ret)) {
 214                 return ret;
 215         }
 216         if (state->dns_err != DNS_RCODE_OK) {
 217                 goto drop;
 218         }
 219         state->out_packet.operation |= state->state.flags;
 220
 221         if (state->state.sign) {
 222                 ret = dns_sign_tsig(state->dns, mem_ctx, &state->state,
 223                                     &state->out_packet, 0);
 224                 if (!W_ERROR_IS_OK(ret)) {
 225                         state->dns_err = DNS_RCODE_SERVFAIL;
 226                         goto drop;
 227                 }
 228         }
 229
 230         ndr_err = ndr_push_struct_blob(
 231                 out, mem_ctx, &state->out_packet,
 232                 (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 233         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 234                 DEBUG(1, ("Failed to push packet: %s!\n",
 235                           ndr_errstr(ndr_err)));
 236                 state->dns_err = DNS_RCODE_SERVFAIL;
 237                 goto drop;
 238         }
 239         return WERR_OK;
 240
 241 drop:
 242         *out = data_blob_talloc(mem_ctx, state->in->data, state->in->length);
 243         if (out->data == NULL) {
 244                 return WERR_NOMEM;
 245         }
 246         out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
 247         out->data[3] |= state->dns_err;
 248         return WERR_OK;
 249 }
 250
 251 struct dns_tcp_call {
 252         struct dns_tcp_connection *dns_conn;
 253         DATA_BLOB in;
 254         DATA_BLOB out;
 255         uint8_t out_hdr[4];
 256         struct iovec out_iov[2];
 257 };
 258
 259 static void dns_tcp_call_process_done(struct tevent_req *subreq);
 260 static void dns_tcp_call_writev_done(struct tevent_req *subreq);
 261
 262 static void dns_tcp_call_loop(struct tevent_req *subreq)
 263 {
 264         struct dns_tcp_connection *dns_conn = tevent_req_callback_data(subreq,
 265                                       struct dns_tcp_connection);
 266         struct dns_server *dns = dns_conn->dns_socket->dns;
 267         struct dns_tcp_call *call;
 268         NTSTATUS status;
 269
 270         call = talloc(dns_conn, struct dns_tcp_call);
 271         if (call == NULL) {
 272                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 273                                 "no memory for dns_tcp_call");
 274                 return;
 275         }
 276         call->dns_conn = dns_conn;
 277
 278         status = tstream_read_pdu_blob_recv(subreq,
 279                                             call,
 280                                             &call->in);
 281         TALLOC_FREE(subreq);
 282         if (!NT_STATUS_IS_OK(status)) {
 283                 const char *reason;
 284
 285                 reason = talloc_asprintf(call, "dns_tcp_call_loop: "
 286                                          "tstream_read_pdu_blob_recv() - %s",
 287                                          nt_errstr(status));
 288                 if (!reason) {
 289                         reason = nt_errstr(status);
 290                 }
 291
 292                 dns_tcp_terminate_connection(dns_conn, reason);
 293                 return;
 294         }
 295
 296         DEBUG(10,("Received DNS TCP packet of length %lu from %s\n",
 297                  (long) call->in.length,
 298                  tsocket_address_string(dns_conn->conn->remote_address, call)));
 299
 300         /* skip length header */
 301         call->in.data += 2;
 302         call->in.length -= 2;
 303
 304         subreq = dns_process_send(call, dns->task->event_ctx, dns,
 305                                   &call->in);
 306         if (subreq == NULL) {
 307                 dns_tcp_terminate_connection(
 308                         dns_conn, "dns_tcp_call_loop: dns_process_send "
 309                         "failed\n");
 310                 return;
 311         }
 312         tevent_req_set_callback(subreq, dns_tcp_call_process_done, call);
 313
 314         /*
 315          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
 316          * packet_full_request_u16 provides the pdu length then.
 317          */
 318         subreq = tstream_read_pdu_blob_send(dns_conn,
 319                                             dns_conn->conn->event.ctx,
 320                                             dns_conn->tstream,
 321                                             2, /* initial_read_size */
 322                                             packet_full_request_u16,
 323                                             dns_conn);
 324         if (subreq == NULL) {
 325                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 326                                 "no memory for tstream_read_pdu_blob_send");
 327                 return;
 328         }
 329         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 330 }
 331
 332 static void dns_tcp_call_process_done(struct tevent_req *subreq)
 333 {
 334         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
 335                         struct dns_tcp_call);
 336         struct dns_tcp_connection *dns_conn = call->dns_conn;
 337         WERROR err;
 338
 339         err = dns_process_recv(subreq, call, &call->out);
 340         TALLOC_FREE(subreq);
 341         if (!W_ERROR_IS_OK(err)) {
 342                 DEBUG(1, ("dns_process returned %s\n", win_errstr(err)));
 343                 dns_tcp_terminate_connection(dns_conn,
 344                                 "dns_tcp_call_loop: process function failed");
 345                 return;
 346         }
 347
 348         /* First add the length of the out buffer */
 349         RSSVAL(call->out_hdr, 0, call->out.length);
 350         call->out_iov[0].iov_base = (char *) call->out_hdr;
 351         call->out_iov[0].iov_len = 2;
 352
 353         call->out_iov[1].iov_base = (char *) call->out.data;
 354         call->out_iov[1].iov_len = call->out.length;
 355
 356         subreq = tstream_writev_queue_send(call,
 357                                            dns_conn->conn->event.ctx,
 358                                            dns_conn->tstream,
 359                                            dns_conn->send_queue,
 360                                            call->out_iov, 2);
 361         if (subreq == NULL) {
 362                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 363                                 "no memory for tstream_writev_queue_send");
 364                 return;
 365         }
 366         tevent_req_set_callback(subreq, dns_tcp_call_writev_done, call);
 367 }
 368
 369 static void dns_tcp_call_writev_done(struct tevent_req *subreq)
 370 {
 371         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
 372                         struct dns_tcp_call);
 373         int sys_errno;
 374         int rc;
 375
 376         rc = tstream_writev_queue_recv(subreq, &sys_errno);
 377         TALLOC_FREE(subreq);
 378         if (rc == -1) {
 379                 const char *reason;
 380
 381                 reason = talloc_asprintf(call, "dns_tcp_call_writev_done: "
 382                                          "tstream_writev_queue_recv() - %d:%s",
 383                                          sys_errno, strerror(sys_errno));
 384                 if (!reason) {
 385                         reason = "dns_tcp_call_writev_done: tstream_writev_queue_recv() failed";
 386                 }
 387
 388                 dns_tcp_terminate_connection(call->dns_conn, reason);
 389                 return;
 390         }
 391
 392         /* We don't care about errors */
 393
 394         talloc_free(call);
 395 }
 396
 397 /*
 398   called when we get a new connection
 399 */
 400 static void dns_tcp_accept(struct stream_connection *conn)
 401 {
 402         struct dns_socket *dns_socket;
 403         struct dns_tcp_connection *dns_conn;
 404         struct tevent_req *subreq;
 405         int rc;
 406
 407         dns_conn = talloc_zero(conn, struct dns_tcp_connection);
 408         if (dns_conn == NULL) {
 409                 stream_terminate_connection(conn,
 410                                 "dns_tcp_accept: out of memory");
 411                 return;
 412         }
 413
 414         dns_conn->send_queue = tevent_queue_create(conn, "dns_tcp_accept");
 415         if (dns_conn->send_queue == NULL) {
 416                 stream_terminate_connection(conn,
 417                                 "dns_tcp_accept: out of memory");
 418                 return;
 419         }
 420
 421         dns_socket = talloc_get_type(conn->private_data, struct dns_socket);
 422
 423         TALLOC_FREE(conn->event.fde);
 424
 425         rc = tstream_bsd_existing_socket(dns_conn,
 426                         socket_get_fd(conn->socket),
 427                         &dns_conn->tstream);
 428         if (rc < 0) {
 429                 stream_terminate_connection(conn,
 430                                 "dns_tcp_accept: out of memory");
 431                 return;
 432         }
 433
 434         dns_conn->conn = conn;
 435         dns_conn->dns_socket = dns_socket;
 436         conn->private_data = dns_conn;
 437
 438         /*
 439          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
 440          * packet_full_request_u16 provides the pdu length then.
 441          */
 442         subreq = tstream_read_pdu_blob_send(dns_conn,
 443                                             dns_conn->conn->event.ctx,
 444                                             dns_conn->tstream,
 445                                             2, /* initial_read_size */
 446                                             packet_full_request_u16,
 447                                             dns_conn);
 448         if (subreq == NULL) {
 449                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_accept: "
 450                                 "no memory for tstream_read_pdu_blob_send");
 451                 return;
 452         }
 453         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 454 }
 455
 456 static const struct stream_server_ops dns_tcp_stream_ops = {
 457         .name                   = "dns_tcp",
 458         .accept_connection      = dns_tcp_accept,
 459         .recv_handler           = dns_tcp_recv,
 460         .send_handler           = dns_tcp_send
 461 };
 462
 463 struct dns_udp_call {
 464         struct dns_udp_socket *sock;
 465         struct tsocket_address *src;
 466         DATA_BLOB in;
 467         DATA_BLOB out;
 468 };
 469
 470 static void dns_udp_call_process_done(struct tevent_req *subreq);
 471 static void dns_udp_call_sendto_done(struct tevent_req *subreq);
 472
 473 static void dns_udp_call_loop(struct tevent_req *subreq)
 474 {
 475         struct dns_udp_socket *sock = tevent_req_callback_data(subreq,
 476                                       struct dns_udp_socket);
 477         struct dns_server *dns = sock->dns_socket->dns;
 478         struct dns_udp_call *call;
 479         uint8_t *buf;
 480         ssize_t len;
 481         int sys_errno;
 482
 483         call = talloc(sock, struct dns_udp_call);
 484         if (call == NULL) {
 485                 talloc_free(call);
 486                 goto done;
 487         }
 488         call->sock = sock;
 489
 490         len = tdgram_recvfrom_recv(subreq, &sys_errno,
 491                                    call, &buf, &call->src);
 492         TALLOC_FREE(subreq);
 493         if (len == -1) {
 494                 talloc_free(call);
 495                 goto done;
 496         }
 497
 498         call->in.data = buf;
 499         call->in.length = len;
 500
 501         DEBUG(10,("Received DNS UDP packet of length %lu from %s\n",
 502                  (long)call->in.length,
 503                  tsocket_address_string(call->src, call)));
 504
 505         subreq = dns_process_send(call, dns->task->event_ctx, dns,
 506                                   &call->in);
 507         if (subreq == NULL) {
 508                 TALLOC_FREE(call);
 509                 goto done;
 510         }
 511         tevent_req_set_callback(subreq, dns_udp_call_process_done, call);
 512
 513 done:
 514         subreq = tdgram_recvfrom_send(sock,
 515                                       sock->dns_socket->dns->task->event_ctx,
 516                                       sock->dgram);
 517         if (subreq == NULL) {
 518                 task_server_terminate(sock->dns_socket->dns->task,
 519                                       "no memory for tdgram_recvfrom_send",
 520                                       true);
 521                 return;
 522         }
 523         tevent_req_set_callback(subreq, dns_udp_call_loop, sock);
 524 }
 525
 526 static void dns_udp_call_process_done(struct tevent_req *subreq)
 527 {
 528         struct dns_udp_call *call = tevent_req_callback_data(
 529                 subreq, struct dns_udp_call);
 530         struct dns_udp_socket *sock = call->sock;
 531         struct dns_server *dns = sock->dns_socket->dns;
 532         WERROR err;
 533
 534         err = dns_process_recv(subreq, call, &call->out);
 535         TALLOC_FREE(subreq);
 536         if (!W_ERROR_IS_OK(err)) {
 537                 DEBUG(1, ("dns_process returned %s\n", win_errstr(err)));
 538                 TALLOC_FREE(call);
 539                 return;
 540         }
 541
 542         subreq = tdgram_sendto_queue_send(call,
 543                                           dns->task->event_ctx,
 544                                           sock->dgram,
 545                                           sock->send_queue,
 546                                           call->out.data,
 547                                           call->out.length,
 548                                           call->src);
 549         if (subreq == NULL) {
 550                 talloc_free(call);
 551                 return;
 552         }
 553         tevent_req_set_callback(subreq, dns_udp_call_sendto_done, call);
 554
 555 }
 556 static void dns_udp_call_sendto_done(struct tevent_req *subreq)
 557 {
 558         struct dns_udp_call *call = tevent_req_callback_data(subreq,
 559                                        struct dns_udp_call);
 560         ssize_t ret;
 561         int sys_errno;
 562
 563         ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
 564
 565         /* We don't care about errors */
 566
 567         talloc_free(call);
 568 }
 569
 570 /*
 571   start listening on the given address
 572 */
 573 static NTSTATUS dns_add_socket(struct dns_server *dns,
 574                                const struct model_ops *model_ops,
 575                                const char *name,
 576                                const char *address,
 577                                uint16_t port)
 578 {
 579         struct dns_socket *dns_socket;
 580         struct dns_udp_socket *dns_udp_socket;
 581         struct tevent_req *udpsubreq;
 582         NTSTATUS status;
 583         int ret;
 584
 585         dns_socket = talloc(dns, struct dns_socket);
 586         NT_STATUS_HAVE_NO_MEMORY(dns_socket);
 587
 588         dns_socket->dns = dns;
 589
 590         ret = tsocket_address_inet_from_strings(dns_socket, "ip",
 591                                                 address, port,
 592                                                 &dns_socket->local_address);
 593         if (ret != 0) {
 594                 status = map_nt_error_from_unix_common(errno);
 595                 return status;
 596         }
 597
 598         status = stream_setup_socket(dns->task,
 599                                      dns->task->event_ctx,
 600                                      dns->task->lp_ctx,
 601                                      model_ops,
 602                                      &dns_tcp_stream_ops,
 603                                      "ip", address, &port,
 604                                      lpcfg_socket_options(dns->task->lp_ctx),
 605                                      dns_socket);
 606         if (!NT_STATUS_IS_OK(status)) {
 607                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 608                          address, port, nt_errstr(status)));
 609                 talloc_free(dns_socket);
 610                 return status;
 611         }
 612
 613         dns_udp_socket = talloc(dns_socket, struct dns_udp_socket);
 614         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket);
 615
 616         dns_udp_socket->dns_socket = dns_socket;
 617
 618         ret = tdgram_inet_udp_socket(dns_socket->local_address,
 619                                      NULL,
 620                                      dns_udp_socket,
 621                                      &dns_udp_socket->dgram);
 622         if (ret != 0) {
 623                 status = map_nt_error_from_unix_common(errno);
 624                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
 625                          address, port, nt_errstr(status)));
 626                 return status;
 627         }
 628
 629         dns_udp_socket->send_queue = tevent_queue_create(dns_udp_socket,
 630                                                          "dns_udp_send_queue");
 631         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket->send_queue);
 632
 633         udpsubreq = tdgram_recvfrom_send(dns_udp_socket,
 634                                          dns->task->event_ctx,
 635                                          dns_udp_socket->dgram);
 636         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
 637         tevent_req_set_callback(udpsubreq, dns_udp_call_loop, dns_udp_socket);
 638
 639         return NT_STATUS_OK;
 640 }
 641
 642 /*
 643   setup our listening sockets on the configured network interfaces
 644 */
 645 static NTSTATUS dns_startup_interfaces(struct dns_server *dns, struct loadparm_context *lp_ctx,
 646                                        struct interface *ifaces)
 647 {
 648         const struct model_ops *model_ops;
 649         int num_interfaces;
 650         TALLOC_CTX *tmp_ctx = talloc_new(dns);
 651         NTSTATUS status;
 652         int i;
 653
 654         /* within the dns task we want to be a single process, so
 655            ask for the single process model ops and pass these to the
 656            stream_setup_socket() call. */
 657         model_ops = process_model_startup("single");
 658         if (!model_ops) {
 659                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 660                 return NT_STATUS_INTERNAL_ERROR;
 661         }
 662
 663         num_interfaces = iface_list_count(ifaces);
 664
 665         for (i=0; i<num_interfaces; i++) {
 666                 const char *address = talloc_strdup(tmp_ctx, iface_list_n_ip(ifaces, i));
 667
 668                 status = dns_add_socket(dns, model_ops, "dns", address, DNS_SERVICE_PORT);
 669                 NT_STATUS_NOT_OK_RETURN(status);
 670         }
 671
 672         talloc_free(tmp_ctx);
 673
 674         return NT_STATUS_OK;
 675 }
 676
 677 static int dns_server_sort_zones(struct ldb_message **m1, struct ldb_message **m2)
 678 {
 679         const char *n1, *n2;
 680         size_t l1, l2;
 681
 682         n1 = ldb_msg_find_attr_as_string(*m1, "name", NULL);
 683         n2 = ldb_msg_find_attr_as_string(*m2, "name", NULL);
 684
 685         l1 = strlen(n1);
 686         l2 = strlen(n2);
 687
 688         /* If the string lengths are not equal just sort by length */
 689         if (l1 != l2) {
 690                 /* If m1 is the larger zone name, return it first */
 691                 return l2 - l1;
 692         }
 693
 694         /*TODO: We need to compare DNs here, we want the DomainDNSZones first */
 695         return 0;
 696 }
 697
 698 static struct dns_server_tkey_store *tkey_store_init(TALLOC_CTX *mem_ctx,
 699                                                      uint16_t size)
 700 {
 701         struct dns_server_tkey_store *buffer = talloc_zero(mem_ctx,
 702                                                 struct dns_server_tkey_store);
 703
 704         if (buffer == NULL) {
 705                 return NULL;
 706         }
 707
 708         buffer->size = size;
 709         buffer->next_idx = 0;
 710
 711         buffer->tkeys = talloc_zero_array(buffer, struct dns_server_tkey *, size);
 712         if (buffer->tkeys == NULL) {
 713                 TALLOC_FREE(buffer);
 714         }
 715
 716         return buffer;
 717 }
 718
 719 static void dns_task_init(struct task_server *task)
 720 {
 721         struct dns_server *dns;
 722         NTSTATUS status;
 723         struct interface *ifaces;
 724         int ret;
 725         struct ldb_result *res;
 726         static const char * const attrs[] = { "name", NULL};
 727         unsigned int i;
 728
 729         switch (lpcfg_server_role(task->lp_ctx)) {
 730         case ROLE_STANDALONE:
 731                 task_server_terminate(task, "dns: no DNS required in standalone configuration", false);
 732                 return;
 733         case ROLE_DOMAIN_MEMBER:
 734                 task_server_terminate(task, "dns: no DNS required in member server configuration", false);
 735                 return;
 736         case ROLE_ACTIVE_DIRECTORY_DC:
 737                 /* Yes, we want a DNS */
 738                 break;
 739         }
 740
 741         load_interface_list(task, task->lp_ctx, &ifaces);
 742
 743         if (iface_list_count(ifaces) == 0) {
 744                 task_server_terminate(task, "dns: no network interfaces configured", false);
 745                 return;
 746         }
 747
 748         task_server_set_title(task, "task[dns]");
 749
 750         dns = talloc_zero(task, struct dns_server);
 751         if (dns == NULL) {
 752                 task_server_terminate(task, "dns: out of memory", true);
 753                 return;
 754         }
 755
 756         dns->task = task;
 757
 758         dns->server_credentials = cli_credentials_init(dns);
 759         if (!dns->server_credentials) {
 760                 task_server_terminate(task, "Failed to init server credentials\n", true);
 761                 return;
 762         }
 763
 764         cli_credentials_set_conf(dns->server_credentials, task->lp_ctx);
 765         status = cli_credentials_set_machine_account(dns->server_credentials, task->lp_ctx);
 766         if (!NT_STATUS_IS_OK(status)) {
 767                 task_server_terminate(task,
 768                         talloc_asprintf(task, "Failed to obtain server credentials, perhaps a standalone server?: %s\n",
 769                                         nt_errstr(status)),
 770                         true);
 771                 return;
 772         }
 773
 774         dns->tkeys = tkey_store_init(dns, TKEY_BUFFER_SIZE);
 775         if (!dns->tkeys) {
 776                 task_server_terminate(task, "Failed to allocate tkey storage\n", true);
 777                 return;
 778         }
 779
 780         dns->samdb = samdb_connect(dns, dns->task->event_ctx, dns->task->lp_ctx,
 781                               system_session(dns->task->lp_ctx), 0);
 782         if (!dns->samdb) {
 783                 task_server_terminate(task, "dns: samdb_connect failed", true);
 784                 return;
 785         }
 786
 787         // TODO: this search does not work against windows
 788         ret = dsdb_search(dns->samdb, dns, &res, NULL, LDB_SCOPE_SUBTREE,
 789                           attrs, DSDB_SEARCH_SEARCH_ALL_PARTITIONS, "(objectClass=dnsZone)");
 790         if (ret != LDB_SUCCESS) {
 791                 task_server_terminate(task,
 792                                       "dns: failed to look up root DNS zones",
 793                                       true);
 794                 return;
 795         }
 796
 797         TYPESAFE_QSORT(res->msgs, res->count, dns_server_sort_zones);
 798
 799         for (i=0; i < res->count; i++) {
 800                 struct dns_server_zone *z;
 801
 802                 z = talloc_zero(dns, struct dns_server_zone);
 803                 if (z == NULL) {
 804                 }
 805
 806                 z->name = ldb_msg_find_attr_as_string(res->msgs[i], "name", NULL);
 807                 z->dn = talloc_move(z, &res->msgs[i]->dn);
 808
 809                 DLIST_ADD_END(dns->zones, z, NULL);
 810         }
 811
 812         status = dns_startup_interfaces(dns, task->lp_ctx, ifaces);
 813         if (!NT_STATUS_IS_OK(status)) {
 814                 task_server_terminate(task, "dns failed to setup interfaces", true);
 815                 return;
 816         }
 817 }
 818
 819 NTSTATUS server_service_dns_init(void)
 820 {
 821         return register_server_service("dns", dns_task_init);
 822 }