source4/dns_server/dns_server.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    DNS server startup
   5
   6    Copyright (C) 2010 Kai Blin  <kai@samba.org>
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "smbd/service_task.h"
  24 #include "smbd/service.h"
  25 #include "smbd/service_stream.h"
  26 #include "smbd/process_model.h"
  27 #include "lib/events/events.h"
  28 #include "lib/socket/socket.h"
  29 #include "lib/tsocket/tsocket.h"
  30 #include "libcli/util/tstream.h"
  31 #include "libcli/util/ntstatus.h"
  32 #include "system/network.h"
  33 #include "lib/stream/packet.h"
  34 #include "lib/socket/netif.h"
  35 #include "dns_server/dns_server.h"
  36 #include "param/param.h"
  37 #include "librpc/ndr/libndr.h"
  38 #include "librpc/gen_ndr/ndr_dns.h"
  39 #include "librpc/gen_ndr/ndr_dnsp.h"
  40 #include <ldb.h>
  41 #include "dsdb/samdb/samdb.h"
  42 #include "dsdb/common/util.h"
  43 #include "auth/session.h"
  44 #include "lib/util/dlinklist.h"
  45
  46 /* hold information about one dns socket */
  47 struct dns_socket {
  48         struct dns_server *dns;
  49         struct tsocket_address *local_address;
  50 };
  51
  52 struct dns_udp_socket {
  53         struct dns_socket *dns_socket;
  54         struct tdgram_context *dgram;
  55         struct tevent_queue *send_queue;
  56 };
  57
  58 /*
  59   state of an open tcp connection
  60 */
  61 struct dns_tcp_connection {
  62         /* stream connection we belong to */
  63         struct stream_connection *conn;
  64
  65         /* the dns_server the connection belongs to */
  66         struct dns_socket *dns_socket;
  67
  68         struct tstream_context *tstream;
  69
  70         struct tevent_queue *send_queue;
  71 };
  72
  73 static void dns_tcp_terminate_connection(struct dns_tcp_connection *dnsconn, const char *reason)
  74 {
  75         stream_terminate_connection(dnsconn->conn, reason);
  76 }
  77
  78 static void dns_tcp_recv(struct stream_connection *conn, uint16_t flags)
  79 {
  80         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
  81                                                              struct dns_tcp_connection);
  82         /* this should never be triggered! */
  83         dns_tcp_terminate_connection(dnsconn, "dns_tcp_recv: called");
  84 }
  85
  86 static void dns_tcp_send(struct stream_connection *conn, uint16_t flags)
  87 {
  88         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
  89                                                              struct dns_tcp_connection);
  90         /* this should never be triggered! */
  91         dns_tcp_terminate_connection(dnsconn, "dns_tcp_send: called");
  92 }
  93
  94 static bool dns_name_match(const char *zone, const char *name, size_t *host_part_len)
  95 {
  96         size_t zl = strlen(zone);
  97         size_t nl = strlen(name);
  98         ssize_t zi, ni;
  99         static const size_t fixup = 'a' - 'A';
 100
 101         if (zl > nl) {
 102                 return false;
 103         }
 104
 105         for (zi = zl, ni = nl; zi >= 0; zi--, ni--) {
 106                 char zc = zone[zi];
 107                 char nc = name[ni];
 108
 109                 /* convert to lower case */
 110                 if (zc >= 'A' && zc <= 'Z') {
 111                         zc += fixup;
 112                 }
 113                 if (nc >= 'A' && nc <= 'Z') {
 114                         nc += fixup;
 115                 }
 116
 117                 if (zc != nc) {
 118                         return false;
 119                 }
 120         }
 121
 122         if (ni >= 0) {
 123                 if (name[ni] != '.') {
 124                         return false;
 125                 }
 126
 127                 ni--;
 128         }
 129
 130         *host_part_len = ni+1;
 131
 132         return true;
 133 }
 134
 135 static NTSTATUS dns_name2dn(struct dns_server *dns,
 136                             TALLOC_CTX *mem_ctx,
 137                             const char *name,
 138                             struct ldb_dn **_dn)
 139 {
 140         struct ldb_dn *base;
 141         struct ldb_dn *dn;
 142         const struct dns_server_zone *z;
 143         size_t host_part_len = 0;
 144
 145         if (name == NULL) {
 146                 return NT_STATUS_INVALID_PARAMETER;
 147         }
 148
 149         /*TODO: Check if 'name' is a valid DNS name */
 150
 151         if (strcmp(name, "") == 0) {
 152                 base = ldb_get_default_basedn(dns->samdb);
 153                 dn = ldb_dn_copy(mem_ctx, base);
 154                 ldb_dn_add_child_fmt(dn, "DC=@,DC=RootDNSServers,CN=MicrosoftDNS,CN=System");
 155                 *_dn = dn;
 156                 return NT_STATUS_OK;
 157         }
 158
 159         for (z = dns->zones; z != NULL; z = z->next) {
 160                 bool match;
 161
 162                 match = dns_name_match(z->name, name, &host_part_len);
 163                 if (match) {
 164                         break;
 165                 }
 166         }
 167
 168         if (z == NULL) {
 169                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 170         }
 171
 172         if (host_part_len == 0) {
 173                 dn = ldb_dn_copy(mem_ctx, z->dn);
 174                 ldb_dn_add_child_fmt(dn, "DC=@");
 175                 *_dn = dn;
 176                 return NT_STATUS_OK;
 177         }
 178
 179         dn = ldb_dn_copy(mem_ctx, z->dn);
 180         ldb_dn_add_child_fmt(dn, "DC=%*.*s", (int)host_part_len, (int)host_part_len, name);
 181         *_dn = dn;
 182         return NT_STATUS_OK;
 183 }
 184
 185 static NTSTATUS handle_question(struct dns_server *dns,
 186                                 TALLOC_CTX *mem_ctx,
 187                                 const struct dns_name_question *question,
 188                                 struct dns_res_rec **answers, uint16_t *ancount)
 189 {
 190         struct dns_res_rec *ans;
 191         struct ldb_dn *dn = NULL;
 192         NTSTATUS status;
 193         static const char * const attrs[] = { "dnsRecord", NULL};
 194         int ret;
 195         uint16_t ai = *ancount;
 196         uint16_t ri;
 197         struct ldb_message *msg = NULL;
 198         struct dnsp_DnssrvRpcRecord *recs;
 199         struct ldb_message_element *el;
 200
 201         status = dns_name2dn(dns, mem_ctx, question->name, &dn);
 202         NT_STATUS_NOT_OK_RETURN(status);
 203
 204         ret = dsdb_search_one(dns->samdb, mem_ctx, &msg, dn,
 205                               LDB_SCOPE_BASE, attrs, 0, "%s", "(objectClass=dnsNode)");
 206         if (ret != LDB_SUCCESS) {
 207                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 208         }
 209
 210         el = ldb_msg_find_element(msg, attrs[0]);
 211         if (el == NULL) {
 212                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 213         }
 214
 215         recs = talloc_array(mem_ctx, struct dnsp_DnssrvRpcRecord, el->num_values);
 216         for (ri = 0; ri < el->num_values; ri++) {
 217                 struct ldb_val *v = &el->values[ri];
 218                 enum ndr_err_code ndr_err;
 219
 220                 ndr_err = ndr_pull_struct_blob(v, recs, &recs[ri],
 221                                 (ndr_pull_flags_fn_t)ndr_pull_dnsp_DnssrvRpcRecord);
 222                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 223                         DEBUG(0, ("Failed to grab dnsp_DnssrvRpcRecord\n"));
 224                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 225                 }
 226         }
 227
 228         ans = talloc_realloc(mem_ctx, *answers, struct dns_res_rec,
 229                              ai + el->num_values);
 230         NT_STATUS_HAVE_NO_MEMORY(ans);
 231
 232         switch (question->question_type) {
 233         case DNS_QTYPE_CNAME:
 234                 for (ri = 0; ri < el->num_values; ri++) {
 235                         if (recs[ri].wType != question->question_type) {
 236                                 continue;
 237                         }
 238
 239                         ZERO_STRUCT(ans[ai]);
 240                         ans[ai].name = talloc_strdup(ans, question->name);
 241                         ans[ai].rr_type = DNS_QTYPE_CNAME;
 242                         ans[ai].rr_class = DNS_QCLASS_IP;
 243                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 244                         ans[ai].rdata.cname_record = talloc_strdup(ans, recs[ri].data.cname);
 245                         ai++;
 246                 }
 247                 break;
 248         case DNS_QTYPE_A:
 249                 for (ri = 0; ri < el->num_values; ri++) {
 250                         if (recs[ri].wType != question->question_type) {
 251                                 continue;
 252                         }
 253
 254                         ZERO_STRUCT(ans[ai]);
 255                         ans[ai].name = talloc_strdup(ans, question->name);
 256                         ans[ai].rr_type = DNS_QTYPE_A;
 257                         ans[ai].rr_class = DNS_QCLASS_IP;
 258                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 259                         ans[ai].rdata.ipv4_record = talloc_strdup(ans, recs[ri].data.ipv4);
 260                         ai++;
 261                 }
 262                 break;
 263         case DNS_QTYPE_AAAA:
 264                 for (ri = 0; ri < el->num_values; ri++) {
 265                         if (recs[ri].wType != question->question_type) {
 266                                 continue;
 267                         }
 268
 269                         ZERO_STRUCT(ans[ai]);
 270                         ans[ai].name = talloc_strdup(ans, question->name);
 271                         ans[ai].rr_type = DNS_QTYPE_AAAA;
 272                         ans[ai].rr_class = DNS_QCLASS_IP;
 273                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 274                         ans[ai].rdata.ipv6_record = recs[ri].data.ipv6;
 275                         ai++;
 276                 }
 277                 break;
 278         case DNS_QTYPE_NS:
 279                 for (ri = 0; ri < el->num_values; ri++) {
 280                         if (recs[ri].wType != question->question_type) {
 281                                 continue;
 282                         }
 283
 284                         ZERO_STRUCT(ans[ai]);
 285                         ans[ai].name = question->name;
 286                         ans[ai].rr_type = DNS_QTYPE_NS;
 287                         ans[ai].rr_class = DNS_QCLASS_IP;
 288                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 289                         ans[ai].rdata.ns_record = recs[ri].data.ns;
 290                         ai++;
 291                 }
 292                 break;
 293         case DNS_QTYPE_SRV:
 294                 for (ri = 0; ri < el->num_values; ri++) {
 295                         if (recs[ri].wType != question->question_type) {
 296                                 continue;
 297                         }
 298
 299                         ZERO_STRUCT(ans[ai]);
 300                         ans[ai].name = question->name;
 301                         ans[ai].rr_type = DNS_QTYPE_SRV;
 302                         ans[ai].rr_class = DNS_QCLASS_IP;
 303                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 304                         ans[ai].rdata.srv_record.priority = recs[ri].data.srv.wPriority;
 305                         ans[ai].rdata.srv_record.weight = recs[ri].data.srv.wWeight;
 306                         ans[ai].rdata.srv_record.port = recs[ri].data.srv.wPort;
 307                         ans[ai].rdata.srv_record.target = recs[ri].data.srv.nameTarget;
 308                         ai++;
 309                 }
 310                 break;
 311         case DNS_QTYPE_SOA:
 312                 for (ri = 0; ri < el->num_values; ri++) {
 313                         if (recs[ri].wType != question->question_type) {
 314                                 continue;
 315                         }
 316
 317                         ZERO_STRUCT(ans[ai]);
 318                         ans[ai].name = question->name;
 319                         ans[ai].rr_type = DNS_QTYPE_SOA;
 320                         ans[ai].rr_class = DNS_QCLASS_IP;
 321                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 322                         ans[ai].rdata.soa_record.mname  = recs[ri].data.soa.mname;
 323                         ans[ai].rdata.soa_record.rname  = recs[ri].data.soa.rname;
 324                         ans[ai].rdata.soa_record.serial = recs[ri].data.soa.serial;
 325                         ans[ai].rdata.soa_record.refresh= recs[ri].data.soa.refresh;
 326                         ans[ai].rdata.soa_record.retry  = recs[ri].data.soa.retry;
 327                         ans[ai].rdata.soa_record.expire = recs[ri].data.soa.expire;
 328                         ans[ai].rdata.soa_record.minimum= recs[ri].data.soa.minimum;
 329                         ai++;
 330                 }
 331                 break;
 332         default:
 333                 return NT_STATUS_NOT_IMPLEMENTED;
 334         }
 335
 336         *ancount = ai;
 337         *answers = ans;
 338
 339         return NT_STATUS_OK;
 340
 341 }
 342
 343 static NTSTATUS dns_server_process_query(struct dns_server *dns,
 344                                          TALLOC_CTX *mem_ctx,
 345                                          struct dns_name_packet *in,
 346                                          struct dns_res_rec **answers,    uint16_t *ancount,
 347                                          struct dns_res_rec **nsrecs,     uint16_t *nscount,
 348                                          struct dns_res_rec **additional, uint16_t *arcount)
 349 {
 350         uint16_t num_answers=0;
 351         struct dns_res_rec *ans=NULL;
 352         int i;
 353         NTSTATUS status;
 354
 355         ans = talloc_array(mem_ctx, struct dns_res_rec, 0);
 356         if (answers == NULL) return NT_STATUS_NO_MEMORY;
 357
 358         for (i = 0; i < in->qdcount; ++i) {
 359                 status = handle_question(dns, mem_ctx, &in->questions[i], &ans, &num_answers);
 360                 NT_STATUS_NOT_OK_RETURN(status);
 361         }
 362
 363         *answers = ans;
 364         *ancount = num_answers;
 365
 366         /*FIXME: Do something for these */
 367         *nsrecs  = NULL;
 368         *nscount = 0;
 369
 370         *additional = NULL;
 371         *arcount    = 0;
 372
 373         return NT_STATUS_OK;
 374 }
 375
 376 static NTSTATUS dns_server_process_update(struct dns_server *dns,
 377                                           TALLOC_CTX *mem_ctx,
 378                                           struct dns_name_packet *in,
 379                                           struct dns_res_rec **prereqs,    uint16_t *prereq_count,
 380                                           struct dns_res_rec **updates,    uint16_t *update_count,
 381                                           struct dns_res_rec **additional, uint16_t *arcount)
 382 {
 383         struct dns_name_question *zone;
 384
 385         if (in->qdcount != 1) {
 386                 return NT_STATUS_NOT_IMPLEMENTED;
 387         }
 388
 389         zone = in->questions;
 390
 391         DEBUG(0, ("Got a dns update request.\n"));
 392
 393
 394         return NT_STATUS_NOT_IMPLEMENTED;
 395 }
 396
 397 static NTSTATUS dns_process(struct dns_server *dns,
 398                             TALLOC_CTX *mem_ctx,
 399                             DATA_BLOB *in,
 400                             DATA_BLOB *out)
 401 {
 402         enum ndr_err_code ndr_err;
 403         NTSTATUS ret;
 404         struct dns_name_packet *in_packet = talloc_zero(mem_ctx, struct dns_name_packet);
 405         /* TODO: We don't really need an out_packet. */
 406         struct dns_name_packet *out_packet = talloc_zero(mem_ctx, struct dns_name_packet);
 407         struct dns_res_rec *answers = NULL, *nsrecs = NULL, *additional = NULL;
 408         uint16_t num_answers = 0 , num_nsrecs = 0, num_additional = 0;
 409         uint16_t reply_code;
 410
 411         if (in_packet == NULL) return NT_STATUS_INVALID_PARAMETER;
 412
 413         dump_data(2, in->data, in->length);
 414
 415         ndr_err = ndr_pull_struct_blob(in, in_packet, in_packet,
 416                         (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 417         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 418                 TALLOC_FREE(in_packet);
 419                 DEBUG(0, ("Failed to parse packet %d!\n", ndr_err));
 420                 return NT_STATUS_COULD_NOT_INTERPRET;
 421         }
 422
 423         NDR_PRINT_DEBUG(dns_name_packet, in_packet);
 424         *out_packet = *in_packet;
 425         out_packet->operation |= DNS_FLAG_REPLY;
 426
 427         switch (in_packet->operation & DNS_OPCODE) {
 428         case DNS_OPCODE_QUERY:
 429
 430                 ret = dns_server_process_query(dns, out_packet, in_packet,
 431                                                &answers, &num_answers,
 432                                                &nsrecs,  &num_nsrecs,
 433                                                &additional, &num_additional);
 434                 reply_code = DNS_RCODE_NXDOMAIN;
 435
 436                 break;
 437         case DNS_OPCODE_REGISTER:
 438                 ret = dns_server_process_update(dns, out_packet, in_packet,
 439                                                 &answers, &num_answers,
 440                                                 &nsrecs,  &num_nsrecs,
 441                                                 &additional, &num_additional);
 442                 reply_code = DNS_RCODE_REFUSED;
 443                 break;
 444         default:
 445                 ret = NT_STATUS_NOT_IMPLEMENTED;
 446                 reply_code = DNS_RCODE_NOTIMP;
 447                 break;
 448         }
 449
 450         if (NT_STATUS_IS_OK(ret)) {
 451                 out_packet->ancount = num_answers;
 452                 out_packet->answers = answers;
 453
 454                 out_packet->nscount = num_nsrecs;
 455                 out_packet->nsrecs  = nsrecs;
 456
 457                 out_packet->arcount = num_additional;
 458                 out_packet->additional = additional;
 459         } else {
 460                 out_packet->operation |= reply_code;
 461         }
 462
 463         NDR_PRINT_DEBUG(dns_name_packet, out_packet);
 464         ndr_err = ndr_push_struct_blob(out, out_packet, out_packet,
 465                         (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 466         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 467                 TALLOC_FREE(in_packet);
 468                 TALLOC_FREE(out_packet);
 469                 DEBUG(0, ("Failed to push packet %d!\n", ndr_err));
 470                 return NT_STATUS_INTERNAL_ERROR;
 471         }
 472
 473         dump_data(2, out->data, out->length);
 474         return NT_STATUS_OK;
 475 }
 476
 477 struct dns_tcp_call {
 478         struct dns_tcp_connection *dns_conn;
 479         DATA_BLOB in;
 480         DATA_BLOB out;
 481         uint8_t out_hdr[4];
 482         struct iovec out_iov[2];
 483 };
 484
 485 static void dns_tcp_call_writev_done(struct tevent_req *subreq);
 486
 487 static void dns_tcp_call_loop(struct tevent_req *subreq)
 488 {
 489         struct dns_tcp_connection *dns_conn = tevent_req_callback_data(subreq,
 490                                       struct dns_tcp_connection);
 491         struct dns_tcp_call *call;
 492         NTSTATUS status;
 493
 494         call = talloc(dns_conn, struct dns_tcp_call);
 495         if (call == NULL) {
 496                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 497                                 "no memory for dns_tcp_call");
 498                 return;
 499         }
 500         call->dns_conn = dns_conn;
 501
 502         status = tstream_read_pdu_blob_recv(subreq,
 503                                             call,
 504                                             &call->in);
 505         TALLOC_FREE(subreq);
 506         if (!NT_STATUS_IS_OK(status)) {
 507                 const char *reason;
 508
 509                 reason = talloc_asprintf(call, "dns_tcp_call_loop: "
 510                                          "tstream_read_pdu_blob_recv() - %s",
 511                                          nt_errstr(status));
 512                 if (!reason) {
 513                         reason = nt_errstr(status);
 514                 }
 515
 516                 dns_tcp_terminate_connection(dns_conn, reason);
 517                 return;
 518         }
 519
 520         DEBUG(10,("Received krb5 TCP packet of length %lu from %s\n",
 521                  (long) call->in.length,
 522                  tsocket_address_string(dns_conn->conn->remote_address, call)));
 523
 524         /* skip length header */
 525         call->in.data +=4;
 526         call->in.length -= 4;
 527
 528         /* Call dns */
 529         status = dns_process(dns_conn->dns_socket->dns, call, &call->in, &call->out);
 530         if (!NT_STATUS_IS_OK(status)) {
 531                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 532                 dns_tcp_terminate_connection(dns_conn,
 533                                 "dns_tcp_call_loop: process function failed");
 534                 return;
 535         }
 536
 537         /* First add the length of the out buffer */
 538         RSIVAL(call->out_hdr, 0, call->out.length);
 539         call->out_iov[0].iov_base = (char *) call->out_hdr;
 540         call->out_iov[0].iov_len = 4;
 541
 542         call->out_iov[1].iov_base = (char *) call->out.data;
 543         call->out_iov[1].iov_len = call->out.length;
 544
 545         subreq = tstream_writev_queue_send(call,
 546                                            dns_conn->conn->event.ctx,
 547                                            dns_conn->tstream,
 548                                            dns_conn->send_queue,
 549                                            call->out_iov, 2);
 550         if (subreq == NULL) {
 551                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 552                                 "no memory for tstream_writev_queue_send");
 553                 return;
 554         }
 555         tevent_req_set_callback(subreq, dns_tcp_call_writev_done, call);
 556
 557         /*
 558          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 559          * packet_full_request_u32 provides the pdu length then.
 560          */
 561         subreq = tstream_read_pdu_blob_send(dns_conn,
 562                                             dns_conn->conn->event.ctx,
 563                                             dns_conn->tstream,
 564                                             4, /* initial_read_size */
 565                                             packet_full_request_u32,
 566                                             dns_conn);
 567         if (subreq == NULL) {
 568                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 569                                 "no memory for tstream_read_pdu_blob_send");
 570                 return;
 571         }
 572         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 573 }
 574
 575 static void dns_tcp_call_writev_done(struct tevent_req *subreq)
 576 {
 577         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
 578                         struct dns_tcp_call);
 579         int sys_errno;
 580         int rc;
 581
 582         rc = tstream_writev_queue_recv(subreq, &sys_errno);
 583         TALLOC_FREE(subreq);
 584         if (rc == -1) {
 585                 const char *reason;
 586
 587                 reason = talloc_asprintf(call, "dns_tcp_call_writev_done: "
 588                                          "tstream_writev_queue_recv() - %d:%s",
 589                                          sys_errno, strerror(sys_errno));
 590                 if (!reason) {
 591                         reason = "dns_tcp_call_writev_done: tstream_writev_queue_recv() failed";
 592                 }
 593
 594                 dns_tcp_terminate_connection(call->dns_conn, reason);
 595                 return;
 596         }
 597
 598         /* We don't care about errors */
 599
 600         talloc_free(call);
 601 }
 602
 603 /*
 604   called when we get a new connection
 605 */
 606 static void dns_tcp_accept(struct stream_connection *conn)
 607 {
 608         struct dns_socket *dns_socket;
 609         struct dns_tcp_connection *dns_conn;
 610         struct tevent_req *subreq;
 611         int rc;
 612
 613         dns_conn = talloc_zero(conn, struct dns_tcp_connection);
 614         if (dns_conn == NULL) {
 615                 stream_terminate_connection(conn,
 616                                 "dns_tcp_accept: out of memory");
 617                 return;
 618         }
 619
 620         dns_conn->send_queue = tevent_queue_create(conn, "dns_tcp_accept");
 621         if (dns_conn->send_queue == NULL) {
 622                 stream_terminate_connection(conn,
 623                                 "dns_tcp_accept: out of memory");
 624                 return;
 625         }
 626
 627         dns_socket = talloc_get_type(conn->private_data, struct dns_socket);
 628
 629         TALLOC_FREE(conn->event.fde);
 630
 631         rc = tstream_bsd_existing_socket(dns_conn,
 632                         socket_get_fd(conn->socket),
 633                         &dns_conn->tstream);
 634         if (rc < 0) {
 635                 stream_terminate_connection(conn,
 636                                 "dns_tcp_accept: out of memory");
 637                 return;
 638         }
 639
 640         dns_conn->conn = conn;
 641         dns_conn->dns_socket = dns_socket;
 642         conn->private_data = dns_conn;
 643
 644         /*
 645          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 646          * packet_full_request_u32 provides the pdu length then.
 647          */
 648         subreq = tstream_read_pdu_blob_send(dns_conn,
 649                                             dns_conn->conn->event.ctx,
 650                                             dns_conn->tstream,
 651                                             4, /* initial_read_size */
 652                                             packet_full_request_u32,
 653                                             dns_conn);
 654         if (subreq == NULL) {
 655                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_accept: "
 656                                 "no memory for tstream_read_pdu_blob_send");
 657                 return;
 658         }
 659         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 660 }
 661
 662 static const struct stream_server_ops dns_tcp_stream_ops = {
 663         .name                   = "dns_tcp",
 664         .accept_connection      = dns_tcp_accept,
 665         .recv_handler           = dns_tcp_recv,
 666         .send_handler           = dns_tcp_send
 667 };
 668
 669 struct dns_udp_call {
 670         struct tsocket_address *src;
 671         DATA_BLOB in;
 672         DATA_BLOB out;
 673 };
 674
 675 static void dns_udp_call_sendto_done(struct tevent_req *subreq);
 676
 677 static void dns_udp_call_loop(struct tevent_req *subreq)
 678 {
 679         struct dns_udp_socket *sock = tevent_req_callback_data(subreq,
 680                                       struct dns_udp_socket);
 681         struct dns_udp_call *call;
 682         uint8_t *buf;
 683         ssize_t len;
 684         int sys_errno;
 685         NTSTATUS status;
 686
 687         call = talloc(sock, struct dns_udp_call);
 688         if (call == NULL) {
 689                 talloc_free(call);
 690                 goto done;
 691         }
 692
 693         len = tdgram_recvfrom_recv(subreq, &sys_errno,
 694                                    call, &buf, &call->src);
 695         TALLOC_FREE(subreq);
 696         if (len == -1) {
 697                 talloc_free(call);
 698                 goto done;
 699         }
 700
 701         call->in.data = buf;
 702         call->in.length = len;
 703
 704         DEBUG(10,("Received krb5 UDP packet of length %lu from %s\n",
 705                  (long)call->in.length,
 706                  tsocket_address_string(call->src, call)));
 707
 708         /* Call krb5 */
 709         status = dns_process(sock->dns_socket->dns, call, &call->in, &call->out);
 710         if (!NT_STATUS_IS_OK(status)) {
 711                 talloc_free(call);
 712                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 713                 goto done;
 714         }
 715
 716         subreq = tdgram_sendto_queue_send(call,
 717                                           sock->dns_socket->dns->task->event_ctx,
 718                                           sock->dgram,
 719                                           sock->send_queue,
 720                                           call->out.data,
 721                                           call->out.length,
 722                                           call->src);
 723         if (subreq == NULL) {
 724                 talloc_free(call);
 725                 goto done;
 726         }
 727         tevent_req_set_callback(subreq, dns_udp_call_sendto_done, call);
 728
 729 done:
 730         subreq = tdgram_recvfrom_send(sock,
 731                                       sock->dns_socket->dns->task->event_ctx,
 732                                       sock->dgram);
 733         if (subreq == NULL) {
 734                 task_server_terminate(sock->dns_socket->dns->task,
 735                                       "no memory for tdgram_recvfrom_send",
 736                                       true);
 737                 return;
 738         }
 739         tevent_req_set_callback(subreq, dns_udp_call_loop, sock);
 740 }
 741
 742 static void dns_udp_call_sendto_done(struct tevent_req *subreq)
 743 {
 744         struct dns_udp_call *call = tevent_req_callback_data(subreq,
 745                                        struct dns_udp_call);
 746         ssize_t ret;
 747         int sys_errno;
 748
 749         ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
 750
 751         /* We don't care about errors */
 752
 753         talloc_free(call);
 754 }
 755
 756 /*
 757   start listening on the given address
 758 */
 759 static NTSTATUS dns_add_socket(struct dns_server *dns,
 760                                const struct model_ops *model_ops,
 761                                const char *name,
 762                                const char *address,
 763                                uint16_t port)
 764 {
 765         struct dns_socket *dns_socket;
 766         struct dns_udp_socket *dns_udp_socket;
 767         struct tevent_req *udpsubreq;
 768         NTSTATUS status;
 769         int ret;
 770
 771         dns_socket = talloc(dns, struct dns_socket);
 772         NT_STATUS_HAVE_NO_MEMORY(dns_socket);
 773
 774         dns_socket->dns = dns;
 775
 776         ret = tsocket_address_inet_from_strings(dns_socket, "ip",
 777                                                 address, port,
 778                                                 &dns_socket->local_address);
 779         if (ret != 0) {
 780                 status = map_nt_error_from_unix(errno);
 781                 return status;
 782         }
 783
 784         status = stream_setup_socket(dns->task->event_ctx,
 785                                      dns->task->lp_ctx,
 786                                      model_ops,
 787                                      &dns_tcp_stream_ops,
 788                                      "ip", address, &port,
 789                                      lpcfg_socket_options(dns->task->lp_ctx),
 790                                      dns_socket);
 791         if (!NT_STATUS_IS_OK(status)) {
 792                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 793                          address, port, nt_errstr(status)));
 794                 talloc_free(dns_socket);
 795                 return status;
 796         }
 797
 798         dns_udp_socket = talloc(dns_socket, struct dns_udp_socket);
 799         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket);
 800
 801         dns_udp_socket->dns_socket = dns_socket;
 802
 803         ret = tdgram_inet_udp_socket(dns_socket->local_address,
 804                                      NULL,
 805                                      dns_udp_socket,
 806                                      &dns_udp_socket->dgram);
 807         if (ret != 0) {
 808                 status = map_nt_error_from_unix(errno);
 809                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
 810                          address, port, nt_errstr(status)));
 811                 return status;
 812         }
 813
 814         dns_udp_socket->send_queue = tevent_queue_create(dns_udp_socket,
 815                                                          "dns_udp_send_queue");
 816         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket->send_queue);
 817
 818         udpsubreq = tdgram_recvfrom_send(dns_udp_socket,
 819                                          dns->task->event_ctx,
 820                                          dns_udp_socket->dgram);
 821         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
 822         tevent_req_set_callback(udpsubreq, dns_udp_call_loop, dns_udp_socket);
 823
 824         return NT_STATUS_OK;
 825 }
 826
 827 /*
 828   setup our listening sockets on the configured network interfaces
 829 */
 830 static NTSTATUS dns_startup_interfaces(struct dns_server *dns, struct loadparm_context *lp_ctx,
 831                                        struct interface *ifaces)
 832 {
 833         const struct model_ops *model_ops;
 834         int num_interfaces;
 835         TALLOC_CTX *tmp_ctx = talloc_new(dns);
 836         NTSTATUS status;
 837         int i;
 838
 839         /* within the dns task we want to be a single process, so
 840            ask for the single process model ops and pass these to the
 841            stream_setup_socket() call. */
 842         model_ops = process_model_startup(dns->task->event_ctx, "single");
 843         if (!model_ops) {
 844                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 845                 return NT_STATUS_INTERNAL_ERROR;
 846         }
 847
 848         num_interfaces = iface_count(ifaces);
 849
 850         for (i=0; i<num_interfaces; i++) {
 851                 const char *address = talloc_strdup(tmp_ctx, iface_n_ip(ifaces, i));
 852
 853                 status = dns_add_socket(dns, model_ops, "dns", address, DNS_SERVICE_PORT);
 854                 NT_STATUS_NOT_OK_RETURN(status);
 855         }
 856
 857         talloc_free(tmp_ctx);
 858
 859         return NT_STATUS_OK;
 860 }
 861
 862 static int dns_server_sort_zones(struct ldb_message **m1, struct ldb_message **m2)
 863 {
 864         const char *n1, *n2;
 865         size_t l1, l2;
 866
 867         n1 = ldb_msg_find_attr_as_string(*m1, "name", NULL);
 868         n2 = ldb_msg_find_attr_as_string(*m2, "name", NULL);
 869
 870         l1 = strlen(n1);
 871         l2 = strlen(n2);
 872
 873         /* If the string lengths are not equal just sort by length */
 874         if (l1 != l2) {
 875                 /* If m1 is the larger zone name, return it first */
 876                 return l2 - l1;
 877         }
 878
 879         /*TODO: We need to compare DNs here, we want the DomainDNSZones first */
 880         return 0;
 881 }
 882
 883 static void dns_task_init(struct task_server *task)
 884 {
 885         struct dns_server *dns;
 886         NTSTATUS status;
 887         struct interface *ifaces;
 888         int ret;
 889         struct ldb_result *res;
 890         struct ldb_dn *rootdn;
 891         static const char * const attrs[] = { "name", NULL};
 892         int i;
 893
 894
 895         switch (lpcfg_server_role(task->lp_ctx)) {
 896         case ROLE_STANDALONE:
 897                 task_server_terminate(task, "dns: no DNS required in standalone configuration", false);
 898                 return;
 899         case ROLE_DOMAIN_MEMBER:
 900                 task_server_terminate(task, "dns: no DNS required in member server configuration", false);
 901                 return;
 902         case ROLE_DOMAIN_CONTROLLER:
 903                 /* Yes, we want a DNS */
 904                 break;
 905         }
 906
 907         load_interfaces(task, lpcfg_interfaces(task->lp_ctx), &ifaces);
 908
 909         if (iface_count(ifaces) == 0) {
 910                 task_server_terminate(task, "dns: no network interfaces configured", false);
 911                 return;
 912         }
 913
 914         task_server_set_title(task, "task[dns]");
 915
 916         dns = talloc_zero(task, struct dns_server);
 917         if (dns == NULL) {
 918                 task_server_terminate(task, "dns: out of memory", true);
 919                 return;
 920         }
 921
 922         dns->task = task;
 923
 924         dns->samdb = samdb_connect(dns, dns->task->event_ctx, dns->task->lp_ctx,
 925                               system_session(dns->task->lp_ctx), 0);
 926         if (!dns->samdb) {
 927                 task_server_terminate(task, "dns: samdb_connect failed", true);
 928                 return;
 929         }
 930
 931         rootdn = ldb_dn_new(dns, dns->samdb, "");
 932         if (rootdn == NULL) {
 933                 task_server_terminate(task, "dns: out of memory", true);
 934                 return;
 935         }
 936
 937         // TODO: this search does not work against windows
 938         ret = dsdb_search(dns->samdb, dns, &res, rootdn, LDB_SCOPE_SUBTREE,
 939                           attrs, DSDB_SEARCH_SEARCH_ALL_PARTITIONS, "(objectClass=dnsZone)");
 940         if (ret != LDB_SUCCESS) {
 941                 task_server_terminate(task,
 942                                       "dns: failed to look up root DNS zones",
 943                                       true);
 944                 return;
 945         }
 946
 947         TYPESAFE_QSORT(res->msgs, res->count, dns_server_sort_zones);
 948
 949         for (i=0; i < res->count; i++) {
 950                 struct dns_server_zone *z;
 951
 952                 z = talloc_zero(dns, struct dns_server_zone);
 953                 if (z == NULL) {
 954                 }
 955
 956                 z->name = ldb_msg_find_attr_as_string(res->msgs[i], "name", NULL);
 957                 z->dn = talloc_move(z, &res->msgs[i]->dn);
 958
 959                 DLIST_ADD_END(dns->zones, z, NULL);
 960         }
 961
 962         status = dns_startup_interfaces(dns, task->lp_ctx, ifaces);
 963         if (!NT_STATUS_IS_OK(status)) {
 964                 task_server_terminate(task, "dns failed to setup interfaces", true);
 965                 return;
 966         }
 967 }
 968
 969 NTSTATUS server_service_dns_init(void)
 970 {
 971         return register_server_service("dns", dns_task_init);
 972 }