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 "auth/session.h"
  43
  44 /* hold information about one dns socket */
  45 struct dns_socket {
  46         struct dns_server *dns;
  47         struct tsocket_address *local_address;
  48 };
  49
  50 struct dns_udp_socket {
  51         struct dns_socket *dns_socket;
  52         struct tdgram_context *dgram;
  53         struct tevent_queue *send_queue;
  54 };
  55
  56 /*
  57   state of an open tcp connection
  58 */
  59 struct dns_tcp_connection {
  60         /* stream connection we belong to */
  61         struct stream_connection *conn;
  62
  63         /* the dns_server the connection belongs to */
  64         struct dns_socket *dns_socket;
  65
  66         struct tstream_context *tstream;
  67
  68         struct tevent_queue *send_queue;
  69 };
  70
  71 static void dns_tcp_terminate_connection(struct dns_tcp_connection *dnsconn, const char *reason)
  72 {
  73         stream_terminate_connection(dnsconn->conn, reason);
  74 }
  75
  76 static void dns_tcp_recv(struct stream_connection *conn, uint16_t flags)
  77 {
  78         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
  79                                                              struct dns_tcp_connection);
  80         /* this should never be triggered! */
  81         dns_tcp_terminate_connection(dnsconn, "dns_tcp_recv: called");
  82 }
  83
  84 static void dns_tcp_send(struct stream_connection *conn, uint16_t flags)
  85 {
  86         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
  87                                                              struct dns_tcp_connection);
  88         /* this should never be triggered! */
  89         dns_tcp_terminate_connection(dnsconn, "dns_tcp_send: called");
  90 }
  91
  92 static NTSTATUS dns_name2dn(struct dns_server *dns,
  93                             TALLOC_CTX *mem_ctx,
  94                             const char *name,
  95                             struct ldb_dn **_dn)
  96 {
  97         struct ldb_dn *base;
  98         struct ldb_dn *dn;
  99         const char *p;
 100
 101         if (name == NULL) {
 102                 return NT_STATUS_INVALID_PARAMETER;
 103         }
 104
 105         /*TODO: Check if 'name' is a valid DNS name */
 106
 107         if (strcmp(name, "") == 0) {
 108                 base = ldb_get_default_basedn(dns->samdb);
 109                 dn = ldb_dn_copy(mem_ctx, base);
 110                 ldb_dn_add_child_fmt(dn, "DC=@,DC=RootDNSServers,CN=MicrosoftDNS,CN=System");
 111                 *_dn = dn;
 112                 return NT_STATUS_OK;
 113         }
 114
 115         p = strcasestr(name, "root-servers.net");
 116         if (p != NULL) {
 117                 base = ldb_get_default_basedn(dns->samdb);
 118                 dn = ldb_dn_copy(mem_ctx, base);
 119                 ldb_dn_add_child_fmt(dn, "DC=%s,DC=RootDNSServers,CN=MicrosoftDNS,CN=System", name);
 120                 *_dn = dn;
 121                 return NT_STATUS_OK;
 122         }
 123
 124         return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 125 }
 126
 127 static NTSTATUS handle_question(struct dns_server *dns,
 128                                 TALLOC_CTX *mem_ctx,
 129                                 const struct dns_name_question *question,
 130                                 struct dns_res_rec **answers, uint16_t *ancount)
 131 {
 132         struct dns_res_rec *ans;
 133         struct ldb_dn *dn = NULL;
 134         NTSTATUS status;
 135         static const char * const attrs[] = { "dnsRecord", NULL};
 136         int ret;
 137         uint16_t ai = *ancount;
 138         uint16_t ri;
 139         struct ldb_message *msg = NULL;
 140         struct dnsp_DnssrvRpcRecord *recs;
 141         struct ldb_message_element *el;
 142
 143         status = dns_name2dn(dns, mem_ctx, question->name, &dn);
 144         NT_STATUS_NOT_OK_RETURN(status);
 145
 146         ret = dsdb_search_one(dns->samdb, mem_ctx, &msg, dn,
 147                               LDB_SCOPE_BASE, attrs, 0, "%s", "(objectClass=dnsNode)");
 148         if (ret != LDB_SUCCESS) {
 149                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 150         }
 151
 152         el = ldb_msg_find_element(msg, attrs[0]);
 153         if (el == NULL) {
 154                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 155         }
 156
 157         recs = talloc_array(mem_ctx, struct dnsp_DnssrvRpcRecord, el->num_values);
 158         for (ri = 0; ri < el->num_values; ri++) {
 159                 struct ldb_val *v = &el->values[ri];
 160                 enum ndr_err_code ndr_err;
 161
 162                 ndr_err = ndr_pull_struct_blob(v, recs, &recs[ri],
 163                                 (ndr_pull_flags_fn_t)ndr_pull_dnsp_DnssrvRpcRecord);
 164                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 165                         DEBUG(0, ("Failed to grab dnsp_DnssrvRpcRecord\n"));
 166                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 167                 }
 168         }
 169
 170         ans = talloc_realloc(mem_ctx, *answers, struct dns_res_rec,
 171                              ai + el->num_values);
 172         NT_STATUS_HAVE_NO_MEMORY(ans);
 173
 174         switch (question->question_type) {
 175         case DNS_QTYPE_A:
 176                 for (ri = 0; ri < el->num_values; ri++) {
 177                         if (recs[ri].wType != question->question_type) {
 178                                 continue;
 179                         }
 180
 181                         ZERO_STRUCT(ans[ai]);
 182                         ans[ai].name = talloc_strdup(ans, question->name);
 183                         ans[ai].rr_type = DNS_QTYPE_A;
 184                         ans[ai].rr_class = DNS_QCLASS_IP;
 185                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 186                         ans[ai].rdata.ipv4_record = talloc_strdup(ans, recs[ri].data.ipv4);
 187                         ai++;
 188                 }
 189                 break;
 190         case DNS_QTYPE_AAAA:
 191                 for (ri = 0; ri < el->num_values; ri++) {
 192                         if (recs[ri].wType != question->question_type) {
 193                                 continue;
 194                         }
 195
 196                         ZERO_STRUCT(ans[ai]);
 197                         ans[ai].name = talloc_strdup(ans, question->name);
 198                         ans[ai].rr_type = DNS_QTYPE_AAAA;
 199                         ans[ai].rr_class = DNS_QCLASS_IP;
 200                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 201                         ans[ai].rdata.ipv6_record = recs[ri].data.ipv6;
 202                         ai++;
 203                 }
 204                 break;
 205         case DNS_QTYPE_NS:
 206                 for (ri = 0; ri < el->num_values; ri++) {
 207                         if (recs[ri].wType != question->question_type) {
 208                                 continue;
 209                         }
 210
 211                         ZERO_STRUCT(ans[ai]);
 212                         ans[ai].name = question->name;
 213                         ans[ai].rr_type = DNS_QTYPE_NS;
 214                         ans[ai].rr_class = DNS_QCLASS_IP;
 215                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 216                         ans[ai].rdata.ns_record = recs[ri].data.ns;
 217                         ai++;
 218                 }
 219                 break;
 220         default:
 221                 return NT_STATUS_NOT_IMPLEMENTED;
 222         }
 223
 224         *ancount = ai;
 225         *answers = ans;
 226
 227         return NT_STATUS_OK;
 228
 229 }
 230
 231 static NTSTATUS compute_reply(struct dns_server *dns,
 232                               TALLOC_CTX *mem_ctx,
 233                               struct dns_name_packet *in,
 234                               struct dns_res_rec **answers,    uint16_t *ancount,
 235                               struct dns_res_rec **nsrecs,     uint16_t *nscount,
 236                               struct dns_res_rec **additional, uint16_t *arcount)
 237 {
 238         uint16_t num_answers=0;
 239         struct dns_res_rec *ans=NULL;
 240         int i;
 241         NTSTATUS status;
 242
 243         ans = talloc_array(mem_ctx, struct dns_res_rec, 0);
 244         if (answers == NULL) return NT_STATUS_NO_MEMORY;
 245
 246         for (i = 0; i < in->qdcount; ++i) {
 247                 status = handle_question(dns, mem_ctx, &in->questions[i], &ans, &num_answers);
 248                 NT_STATUS_NOT_OK_RETURN(status);
 249         }
 250
 251         *answers = ans;
 252         *ancount = num_answers;
 253
 254         /*FIXME: Do something for these */
 255         *nsrecs  = NULL;
 256         *nscount = 0;
 257
 258         *additional = NULL;
 259         *arcount    = 0;
 260
 261         return NT_STATUS_OK;
 262 }
 263
 264 static NTSTATUS dns_process(struct dns_server *dns,
 265                             TALLOC_CTX *mem_ctx,
 266                             DATA_BLOB *in,
 267                             DATA_BLOB *out)
 268 {
 269         enum ndr_err_code ndr_err;
 270         NTSTATUS ret;
 271         struct dns_name_packet *in_packet = talloc_zero(mem_ctx, struct dns_name_packet);
 272         struct dns_name_packet *out_packet = talloc_zero(mem_ctx, struct dns_name_packet);
 273         struct dns_res_rec *answers, *nsrecs, *additional;
 274         uint16_t num_answers, num_nsrecs, num_additional;
 275
 276         if (in_packet == NULL) return NT_STATUS_INVALID_PARAMETER;
 277
 278         dump_data(2, in->data, in->length);
 279
 280         ndr_err = ndr_pull_struct_blob(in, in_packet, in_packet,
 281                         (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 282         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 283                 TALLOC_FREE(in_packet);
 284                 DEBUG(0, ("Failed to parse packet %d!\n", ndr_err));
 285                 return NT_STATUS_COULD_NOT_INTERPRET;
 286         }
 287
 288         NDR_PRINT_DEBUG(dns_name_packet, in_packet);
 289         out_packet->id = in_packet->id;
 290         out_packet->operation = DNS_FLAG_REPLY | DNS_FLAG_AUTHORITATIVE |
 291                                 DNS_FLAG_RECURSION_DESIRED | DNS_FLAG_RECURSION_AVAIL;
 292
 293         out_packet->qdcount = in_packet->qdcount;
 294         out_packet->questions = in_packet->questions;
 295
 296         out_packet->ancount = 0;
 297         out_packet->answers = NULL;
 298
 299         out_packet->nscount = 0;
 300         out_packet->nsrecs  = NULL;
 301
 302         out_packet->arcount = 0;
 303         out_packet->additional = NULL;
 304
 305         ret = compute_reply(dns, out_packet, in_packet, &answers, &num_answers,
 306                             &nsrecs, &num_nsrecs, &additional, &num_additional);
 307
 308         if (NT_STATUS_IS_OK(ret)) {
 309                 out_packet->ancount = num_answers;
 310                 out_packet->answers = answers;
 311
 312                 out_packet->nscount = num_nsrecs;
 313                 out_packet->nsrecs  = nsrecs;
 314
 315                 out_packet->arcount = num_additional;
 316                 out_packet->additional = additional;
 317         }
 318
 319         NDR_PRINT_DEBUG(dns_name_packet, out_packet);
 320         ndr_err = ndr_push_struct_blob(out, out_packet, out_packet,
 321                         (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 322         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 323                 TALLOC_FREE(in_packet);
 324                 TALLOC_FREE(out_packet);
 325                 DEBUG(0, ("Failed to push packet %d!\n", ndr_err));
 326                 return NT_STATUS_INTERNAL_ERROR;
 327         }
 328
 329         dump_data(2, out->data, out->length);
 330         return NT_STATUS_OK;
 331 }
 332
 333 struct dns_tcp_call {
 334         struct dns_tcp_connection *dns_conn;
 335         DATA_BLOB in;
 336         DATA_BLOB out;
 337         uint8_t out_hdr[4];
 338         struct iovec out_iov[2];
 339 };
 340
 341 static void dns_tcp_call_writev_done(struct tevent_req *subreq);
 342
 343 static void dns_tcp_call_loop(struct tevent_req *subreq)
 344 {
 345         struct dns_tcp_connection *dns_conn = tevent_req_callback_data(subreq,
 346                                       struct dns_tcp_connection);
 347         struct dns_tcp_call *call;
 348         NTSTATUS status;
 349
 350         call = talloc(dns_conn, struct dns_tcp_call);
 351         if (call == NULL) {
 352                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 353                                 "no memory for dns_tcp_call");
 354                 return;
 355         }
 356         call->dns_conn = dns_conn;
 357
 358         status = tstream_read_pdu_blob_recv(subreq,
 359                                             call,
 360                                             &call->in);
 361         TALLOC_FREE(subreq);
 362         if (!NT_STATUS_IS_OK(status)) {
 363                 const char *reason;
 364
 365                 reason = talloc_asprintf(call, "dns_tcp_call_loop: "
 366                                          "tstream_read_pdu_blob_recv() - %s",
 367                                          nt_errstr(status));
 368                 if (!reason) {
 369                         reason = nt_errstr(status);
 370                 }
 371
 372                 dns_tcp_terminate_connection(dns_conn, reason);
 373                 return;
 374         }
 375
 376         DEBUG(10,("Received krb5 TCP packet of length %lu from %s\n",
 377                  (long) call->in.length,
 378                  tsocket_address_string(dns_conn->conn->remote_address, call)));
 379
 380         /* skip length header */
 381         call->in.data +=4;
 382         call->in.length -= 4;
 383
 384         /* Call dns */
 385         status = dns_process(dns_conn->dns_socket->dns, call, &call->in, &call->out);
 386         if (!NT_STATUS_IS_OK(status)) {
 387                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 388                 dns_tcp_terminate_connection(dns_conn,
 389                                 "dns_tcp_call_loop: process function failed");
 390                 return;
 391         }
 392
 393         /* First add the length of the out buffer */
 394         RSIVAL(call->out_hdr, 0, call->out.length);
 395         call->out_iov[0].iov_base = (char *) call->out_hdr;
 396         call->out_iov[0].iov_len = 4;
 397
 398         call->out_iov[1].iov_base = (char *) call->out.data;
 399         call->out_iov[1].iov_len = call->out.length;
 400
 401         subreq = tstream_writev_queue_send(call,
 402                                            dns_conn->conn->event.ctx,
 403                                            dns_conn->tstream,
 404                                            dns_conn->send_queue,
 405                                            call->out_iov, 2);
 406         if (subreq == NULL) {
 407                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 408                                 "no memory for tstream_writev_queue_send");
 409                 return;
 410         }
 411         tevent_req_set_callback(subreq, dns_tcp_call_writev_done, call);
 412
 413         /*
 414          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 415          * packet_full_request_u32 provides the pdu length then.
 416          */
 417         subreq = tstream_read_pdu_blob_send(dns_conn,
 418                                             dns_conn->conn->event.ctx,
 419                                             dns_conn->tstream,
 420                                             4, /* initial_read_size */
 421                                             packet_full_request_u32,
 422                                             dns_conn);
 423         if (subreq == NULL) {
 424                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 425                                 "no memory for tstream_read_pdu_blob_send");
 426                 return;
 427         }
 428         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 429 }
 430
 431 static void dns_tcp_call_writev_done(struct tevent_req *subreq)
 432 {
 433         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
 434                         struct dns_tcp_call);
 435         int sys_errno;
 436         int rc;
 437
 438         rc = tstream_writev_queue_recv(subreq, &sys_errno);
 439         TALLOC_FREE(subreq);
 440         if (rc == -1) {
 441                 const char *reason;
 442
 443                 reason = talloc_asprintf(call, "dns_tcp_call_writev_done: "
 444                                          "tstream_writev_queue_recv() - %d:%s",
 445                                          sys_errno, strerror(sys_errno));
 446                 if (!reason) {
 447                         reason = "dns_tcp_call_writev_done: tstream_writev_queue_recv() failed";
 448                 }
 449
 450                 dns_tcp_terminate_connection(call->dns_conn, reason);
 451                 return;
 452         }
 453
 454         /* We don't care about errors */
 455
 456         talloc_free(call);
 457 }
 458
 459 /*
 460   called when we get a new connection
 461 */
 462 static void dns_tcp_accept(struct stream_connection *conn)
 463 {
 464         struct dns_socket *dns_socket;
 465         struct dns_tcp_connection *dns_conn;
 466         struct tevent_req *subreq;
 467         int rc;
 468
 469         dns_conn = talloc_zero(conn, struct dns_tcp_connection);
 470         if (dns_conn == NULL) {
 471                 stream_terminate_connection(conn,
 472                                 "dns_tcp_accept: out of memory");
 473                 return;
 474         }
 475
 476         dns_conn->send_queue = tevent_queue_create(conn, "dns_tcp_accept");
 477         if (dns_conn->send_queue == NULL) {
 478                 stream_terminate_connection(conn,
 479                                 "dns_tcp_accept: out of memory");
 480                 return;
 481         }
 482
 483         dns_socket = talloc_get_type(conn->private_data, struct dns_socket);
 484
 485         TALLOC_FREE(conn->event.fde);
 486
 487         rc = tstream_bsd_existing_socket(dns_conn,
 488                         socket_get_fd(conn->socket),
 489                         &dns_conn->tstream);
 490         if (rc < 0) {
 491                 stream_terminate_connection(conn,
 492                                 "dns_tcp_accept: out of memory");
 493                 return;
 494         }
 495
 496         dns_conn->conn = conn;
 497         dns_conn->dns_socket = dns_socket;
 498         conn->private_data = dns_conn;
 499
 500         /*
 501          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 502          * packet_full_request_u32 provides the pdu length then.
 503          */
 504         subreq = tstream_read_pdu_blob_send(dns_conn,
 505                                             dns_conn->conn->event.ctx,
 506                                             dns_conn->tstream,
 507                                             4, /* initial_read_size */
 508                                             packet_full_request_u32,
 509                                             dns_conn);
 510         if (subreq == NULL) {
 511                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_accept: "
 512                                 "no memory for tstream_read_pdu_blob_send");
 513                 return;
 514         }
 515         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 516 }
 517
 518 static const struct stream_server_ops dns_tcp_stream_ops = {
 519         .name                   = "dns_tcp",
 520         .accept_connection      = dns_tcp_accept,
 521         .recv_handler           = dns_tcp_recv,
 522         .send_handler           = dns_tcp_send
 523 };
 524
 525 struct dns_udp_call {
 526         struct tsocket_address *src;
 527         DATA_BLOB in;
 528         DATA_BLOB out;
 529 };
 530
 531 static void dns_udp_call_sendto_done(struct tevent_req *subreq);
 532
 533 static void dns_udp_call_loop(struct tevent_req *subreq)
 534 {
 535         struct dns_udp_socket *sock = tevent_req_callback_data(subreq,
 536                                       struct dns_udp_socket);
 537         struct dns_udp_call *call;
 538         uint8_t *buf;
 539         ssize_t len;
 540         int sys_errno;
 541         NTSTATUS status;
 542
 543         call = talloc(sock, struct dns_udp_call);
 544         if (call == NULL) {
 545                 talloc_free(call);
 546                 goto done;
 547         }
 548
 549         len = tdgram_recvfrom_recv(subreq, &sys_errno,
 550                                    call, &buf, &call->src);
 551         TALLOC_FREE(subreq);
 552         if (len == -1) {
 553                 talloc_free(call);
 554                 goto done;
 555         }
 556
 557         call->in.data = buf;
 558         call->in.length = len;
 559
 560         DEBUG(10,("Received krb5 UDP packet of length %lu from %s\n",
 561                  (long)call->in.length,
 562                  tsocket_address_string(call->src, call)));
 563
 564         /* Call krb5 */
 565         status = dns_process(sock->dns_socket->dns, call, &call->in, &call->out);
 566         if (!NT_STATUS_IS_OK(status)) {
 567                 talloc_free(call);
 568                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 569                 goto done;
 570         }
 571
 572         subreq = tdgram_sendto_queue_send(call,
 573                                           sock->dns_socket->dns->task->event_ctx,
 574                                           sock->dgram,
 575                                           sock->send_queue,
 576                                           call->out.data,
 577                                           call->out.length,
 578                                           call->src);
 579         if (subreq == NULL) {
 580                 talloc_free(call);
 581                 goto done;
 582         }
 583         tevent_req_set_callback(subreq, dns_udp_call_sendto_done, call);
 584
 585 done:
 586         subreq = tdgram_recvfrom_send(sock,
 587                                       sock->dns_socket->dns->task->event_ctx,
 588                                       sock->dgram);
 589         if (subreq == NULL) {
 590                 task_server_terminate(sock->dns_socket->dns->task,
 591                                       "no memory for tdgram_recvfrom_send",
 592                                       true);
 593                 return;
 594         }
 595         tevent_req_set_callback(subreq, dns_udp_call_loop, sock);
 596 }
 597
 598 static void dns_udp_call_sendto_done(struct tevent_req *subreq)
 599 {
 600         struct dns_udp_call *call = tevent_req_callback_data(subreq,
 601                                        struct dns_udp_call);
 602         ssize_t ret;
 603         int sys_errno;
 604
 605         ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
 606
 607         /* We don't care about errors */
 608
 609         talloc_free(call);
 610 }
 611
 612 /*
 613   start listening on the given address
 614 */
 615 static NTSTATUS dns_add_socket(struct dns_server *dns,
 616                                const struct model_ops *model_ops,
 617                                const char *name,
 618                                const char *address,
 619                                uint16_t port)
 620 {
 621         struct dns_socket *dns_socket;
 622         struct dns_udp_socket *dns_udp_socket;
 623         struct tevent_req *udpsubreq;
 624         NTSTATUS status;
 625         int ret;
 626
 627         dns_socket = talloc(dns, struct dns_socket);
 628         NT_STATUS_HAVE_NO_MEMORY(dns_socket);
 629
 630         dns_socket->dns = dns;
 631
 632         ret = tsocket_address_inet_from_strings(dns_socket, "ip",
 633                                                 address, port,
 634                                                 &dns_socket->local_address);
 635         if (ret != 0) {
 636                 status = map_nt_error_from_unix(errno);
 637                 return status;
 638         }
 639
 640         status = stream_setup_socket(dns->task->event_ctx,
 641                                      dns->task->lp_ctx,
 642                                      model_ops,
 643                                      &dns_tcp_stream_ops,
 644                                      "ip", address, &port,
 645                                      lpcfg_socket_options(dns->task->lp_ctx),
 646                                      dns_socket);
 647         if (!NT_STATUS_IS_OK(status)) {
 648                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 649                          address, port, nt_errstr(status)));
 650                 talloc_free(dns_socket);
 651                 return status;
 652         }
 653
 654         dns_udp_socket = talloc(dns_socket, struct dns_udp_socket);
 655         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket);
 656
 657         dns_udp_socket->dns_socket = dns_socket;
 658
 659         ret = tdgram_inet_udp_socket(dns_socket->local_address,
 660                                      NULL,
 661                                      dns_udp_socket,
 662                                      &dns_udp_socket->dgram);
 663         if (ret != 0) {
 664                 status = map_nt_error_from_unix(errno);
 665                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
 666                          address, port, nt_errstr(status)));
 667                 return status;
 668         }
 669
 670         dns_udp_socket->send_queue = tevent_queue_create(dns_udp_socket,
 671                                                          "dns_udp_send_queue");
 672         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket->send_queue);
 673
 674         udpsubreq = tdgram_recvfrom_send(dns_udp_socket,
 675                                          dns->task->event_ctx,
 676                                          dns_udp_socket->dgram);
 677         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
 678         tevent_req_set_callback(udpsubreq, dns_udp_call_loop, dns_udp_socket);
 679
 680         return NT_STATUS_OK;
 681 }
 682
 683 /*
 684   setup our listening sockets on the configured network interfaces
 685 */
 686 static NTSTATUS dns_startup_interfaces(struct dns_server *dns, struct loadparm_context *lp_ctx,
 687                                        struct interface *ifaces)
 688 {
 689         const struct model_ops *model_ops;
 690         int num_interfaces;
 691         TALLOC_CTX *tmp_ctx = talloc_new(dns);
 692         NTSTATUS status;
 693         int i;
 694
 695         /* within the dns task we want to be a single process, so
 696            ask for the single process model ops and pass these to the
 697            stream_setup_socket() call. */
 698         model_ops = process_model_startup(dns->task->event_ctx, "single");
 699         if (!model_ops) {
 700                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 701                 return NT_STATUS_INTERNAL_ERROR;
 702         }
 703
 704         num_interfaces = iface_count(ifaces);
 705
 706         for (i=0; i<num_interfaces; i++) {
 707                 const char *address = talloc_strdup(tmp_ctx, iface_n_ip(ifaces, i));
 708
 709                 status = dns_add_socket(dns, model_ops, "dns", address, DNS_SERVICE_PORT);
 710                 NT_STATUS_NOT_OK_RETURN(status);
 711         }
 712
 713         talloc_free(tmp_ctx);
 714
 715         return NT_STATUS_OK;
 716 }
 717 static void dns_task_init(struct task_server *task)
 718 {
 719         struct dns_server *dns;
 720         NTSTATUS status;
 721         struct interface *ifaces;
 722
 723         switch (lpcfg_server_role(task->lp_ctx)) {
 724         case ROLE_STANDALONE:
 725                 task_server_terminate(task, "dns: no DNS required in standalone configuration", false);
 726                 return;
 727         case ROLE_DOMAIN_MEMBER:
 728                 task_server_terminate(task, "dns: no DNS required in member server configuration", false);
 729                 return;
 730         case ROLE_DOMAIN_CONTROLLER:
 731                 /* Yes, we want a DNS */
 732                 break;
 733         }
 734
 735         load_interfaces(task, lpcfg_interfaces(task->lp_ctx), &ifaces);
 736
 737         if (iface_count(ifaces) == 0) {
 738                 task_server_terminate(task, "dns: no network interfaces configured", false);
 739                 return;
 740         }
 741
 742         task_server_set_title(task, "task[dns]");
 743
 744         dns = talloc(task, struct dns_server);
 745         if (dns == NULL) {
 746                 task_server_terminate(task, "dns: out of memory", true);
 747                 return;
 748         }
 749
 750         dns->task = task;
 751
 752         /* Connect to a SAMDB with system privileges for fetching the old pw
 753          * hashes. */
 754         dns->samdb = samdb_connect(dns, dns->task->event_ctx, dns->task->lp_ctx,
 755                               system_session(dns->task->lp_ctx), 0);
 756         if (!dns->samdb) {
 757                 task_server_terminate(task, "dns: samdb_connect failed", true);
 758                 return;
 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 }