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 NTSTATUS dns_err_to_ntstatus(enum dns_rcode rcode)
  95 {
  96         switch (rcode) {
  97         case DNS_RCODE_OK: return NT_STATUS_OK;
  98         case DNS_RCODE_FORMERR: return NT_STATUS_INVALID_PARAMETER;
  99         case DNS_RCODE_SERVFAIL: return NT_STATUS_INTERNAL_ERROR;
 100         case DNS_RCODE_NXDOMAIN: return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 101         case DNS_RCODE_NOTIMP: return NT_STATUS_NOT_IMPLEMENTED;
 102         case DNS_RCODE_REFUSED: return NT_STATUS_ACCESS_DENIED;
 103         case DNS_RCODE_NOTAUTH: return NT_STATUS_FOOBAR;
 104         default: return NT_STATUS_NONE_MAPPED;
 105         }
 106 }
 107
 108 static uint8_t ntstatus_to_dns_err(NTSTATUS status)
 109 {
 110         if (NT_STATUS_EQUAL(NT_STATUS_OK, status)) {
 111                 return DNS_RCODE_OK;
 112         } else if (NT_STATUS_EQUAL(NT_STATUS_INVALID_PARAMETER, status)) {
 113                 return DNS_RCODE_FORMERR;
 114         } else if (NT_STATUS_EQUAL(NT_STATUS_INTERNAL_ERROR, status)) {
 115                 return DNS_RCODE_SERVFAIL;
 116         } else if (NT_STATUS_EQUAL(NT_STATUS_OBJECT_NAME_NOT_FOUND, status)) {
 117                 return DNS_RCODE_NXDOMAIN;
 118         } else if (NT_STATUS_EQUAL(NT_STATUS_NOT_IMPLEMENTED, status)) {
 119                 return DNS_RCODE_NOTIMP;
 120         } else if (NT_STATUS_EQUAL(NT_STATUS_ACCESS_DENIED, status)) {
 121                 return DNS_RCODE_REFUSED;
 122         } else if (NT_STATUS_EQUAL(NT_STATUS_FOOBAR, status)) {
 123                 return DNS_RCODE_NOTAUTH;
 124         }
 125         DEBUG(0, ("No mapping exists for %s\n", nt_errstr(status)));
 126 }
 127
 128 static bool dns_name_match(const char *zone, const char *name, size_t *host_part_len)
 129 {
 130         size_t zl = strlen(zone);
 131         size_t nl = strlen(name);
 132         ssize_t zi, ni;
 133         static const size_t fixup = 'a' - 'A';
 134
 135         if (zl > nl) {
 136                 return false;
 137         }
 138
 139         for (zi = zl, ni = nl; zi >= 0; zi--, ni--) {
 140                 char zc = zone[zi];
 141                 char nc = name[ni];
 142
 143                 /* convert to lower case */
 144                 if (zc >= 'A' && zc <= 'Z') {
 145                         zc += fixup;
 146                 }
 147                 if (nc >= 'A' && nc <= 'Z') {
 148                         nc += fixup;
 149                 }
 150
 151                 if (zc != nc) {
 152                         return false;
 153                 }
 154         }
 155
 156         if (ni >= 0) {
 157                 if (name[ni] != '.') {
 158                         return false;
 159                 }
 160
 161                 ni--;
 162         }
 163
 164         *host_part_len = ni+1;
 165
 166         return true;
 167 }
 168
 169 static NTSTATUS dns_name2dn(struct dns_server *dns,
 170                             TALLOC_CTX *mem_ctx,
 171                             const char *name,
 172                             struct ldb_dn **_dn)
 173 {
 174         struct ldb_dn *base;
 175         struct ldb_dn *dn;
 176         const struct dns_server_zone *z;
 177         size_t host_part_len = 0;
 178
 179         if (name == NULL) {
 180                 return NT_STATUS_INVALID_PARAMETER;
 181         }
 182
 183         /*TODO: Check if 'name' is a valid DNS name */
 184
 185         if (strcmp(name, "") == 0) {
 186                 base = ldb_get_default_basedn(dns->samdb);
 187                 dn = ldb_dn_copy(mem_ctx, base);
 188                 ldb_dn_add_child_fmt(dn, "DC=@,DC=RootDNSServers,CN=MicrosoftDNS,CN=System");
 189                 *_dn = dn;
 190                 return NT_STATUS_OK;
 191         }
 192
 193         for (z = dns->zones; z != NULL; z = z->next) {
 194                 bool match;
 195
 196                 match = dns_name_match(z->name, name, &host_part_len);
 197                 if (match) {
 198                         break;
 199                 }
 200         }
 201
 202         if (z == NULL) {
 203                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 204         }
 205
 206         if (host_part_len == 0) {
 207                 dn = ldb_dn_copy(mem_ctx, z->dn);
 208                 ldb_dn_add_child_fmt(dn, "DC=@");
 209                 *_dn = dn;
 210                 return NT_STATUS_OK;
 211         }
 212
 213         dn = ldb_dn_copy(mem_ctx, z->dn);
 214         ldb_dn_add_child_fmt(dn, "DC=%*.*s", (int)host_part_len, (int)host_part_len, name);
 215         *_dn = dn;
 216         return NT_STATUS_OK;
 217 }
 218
 219 static NTSTATUS handle_question(struct dns_server *dns,
 220                                 TALLOC_CTX *mem_ctx,
 221                                 const struct dns_name_question *question,
 222                                 struct dns_res_rec **answers, uint16_t *ancount)
 223 {
 224         struct dns_res_rec *ans;
 225         struct ldb_dn *dn = NULL;
 226         NTSTATUS status;
 227         static const char * const attrs[] = { "dnsRecord", NULL};
 228         int ret;
 229         uint16_t ai = *ancount;
 230         uint16_t ri;
 231         struct ldb_message *msg = NULL;
 232         struct dnsp_DnssrvRpcRecord *recs;
 233         struct ldb_message_element *el;
 234
 235         status = dns_name2dn(dns, mem_ctx, question->name, &dn);
 236         NT_STATUS_NOT_OK_RETURN(status);
 237
 238         ret = dsdb_search_one(dns->samdb, mem_ctx, &msg, dn,
 239                               LDB_SCOPE_BASE, attrs, 0, "%s", "(objectClass=dnsNode)");
 240         if (ret != LDB_SUCCESS) {
 241                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 242         }
 243
 244         el = ldb_msg_find_element(msg, attrs[0]);
 245         if (el == NULL) {
 246                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 247         }
 248
 249         recs = talloc_array(mem_ctx, struct dnsp_DnssrvRpcRecord, el->num_values);
 250         for (ri = 0; ri < el->num_values; ri++) {
 251                 struct ldb_val *v = &el->values[ri];
 252                 enum ndr_err_code ndr_err;
 253
 254                 ndr_err = ndr_pull_struct_blob(v, recs, &recs[ri],
 255                                 (ndr_pull_flags_fn_t)ndr_pull_dnsp_DnssrvRpcRecord);
 256                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 257                         DEBUG(0, ("Failed to grab dnsp_DnssrvRpcRecord\n"));
 258                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 259                 }
 260         }
 261
 262         ans = talloc_realloc(mem_ctx, *answers, struct dns_res_rec,
 263                              ai + el->num_values);
 264         NT_STATUS_HAVE_NO_MEMORY(ans);
 265
 266         switch (question->question_type) {
 267         case DNS_QTYPE_CNAME:
 268                 for (ri = 0; ri < el->num_values; ri++) {
 269                         if (recs[ri].wType != question->question_type) {
 270                                 continue;
 271                         }
 272
 273                         ZERO_STRUCT(ans[ai]);
 274                         ans[ai].name = talloc_strdup(ans, question->name);
 275                         ans[ai].rr_type = DNS_QTYPE_CNAME;
 276                         ans[ai].rr_class = DNS_QCLASS_IP;
 277                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 278                         ans[ai].length = UINT16_MAX;
 279                         ans[ai].rdata.cname_record = talloc_strdup(ans, recs[ri].data.cname);
 280                         ai++;
 281                 }
 282                 break;
 283         case DNS_QTYPE_A:
 284                 for (ri = 0; ri < el->num_values; ri++) {
 285                         if (recs[ri].wType != question->question_type) {
 286                                 continue;
 287                         }
 288
 289                         ZERO_STRUCT(ans[ai]);
 290                         ans[ai].name = talloc_strdup(ans, question->name);
 291                         ans[ai].rr_type = DNS_QTYPE_A;
 292                         ans[ai].rr_class = DNS_QCLASS_IP;
 293                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 294                         ans[ai].length = UINT16_MAX;
 295                         ans[ai].rdata.ipv4_record = talloc_strdup(ans, recs[ri].data.ipv4);
 296                         ai++;
 297                 }
 298                 break;
 299         case DNS_QTYPE_AAAA:
 300                 for (ri = 0; ri < el->num_values; ri++) {
 301                         if (recs[ri].wType != question->question_type) {
 302                                 continue;
 303                         }
 304
 305                         ZERO_STRUCT(ans[ai]);
 306                         ans[ai].name = talloc_strdup(ans, question->name);
 307                         ans[ai].rr_type = DNS_QTYPE_AAAA;
 308                         ans[ai].rr_class = DNS_QCLASS_IP;
 309                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 310                         ans[ai].length = UINT16_MAX;
 311                         ans[ai].rdata.ipv6_record = recs[ri].data.ipv6;
 312                         ai++;
 313                 }
 314                 break;
 315         case DNS_QTYPE_NS:
 316                 for (ri = 0; ri < el->num_values; ri++) {
 317                         if (recs[ri].wType != question->question_type) {
 318                                 continue;
 319                         }
 320
 321                         ZERO_STRUCT(ans[ai]);
 322                         ans[ai].name = question->name;
 323                         ans[ai].rr_type = DNS_QTYPE_NS;
 324                         ans[ai].rr_class = DNS_QCLASS_IP;
 325                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 326                         ans[ai].length = UINT16_MAX;
 327                         ans[ai].rdata.ns_record = recs[ri].data.ns;
 328                         ai++;
 329                 }
 330                 break;
 331         case DNS_QTYPE_SRV:
 332                 for (ri = 0; ri < el->num_values; ri++) {
 333                         if (recs[ri].wType != question->question_type) {
 334                                 continue;
 335                         }
 336
 337                         ZERO_STRUCT(ans[ai]);
 338                         ans[ai].name = question->name;
 339                         ans[ai].rr_type = DNS_QTYPE_SRV;
 340                         ans[ai].rr_class = DNS_QCLASS_IP;
 341                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 342                         ans[ai].length = UINT16_MAX;
 343                         ans[ai].rdata.srv_record.priority = recs[ri].data.srv.wPriority;
 344                         ans[ai].rdata.srv_record.weight = recs[ri].data.srv.wWeight;
 345                         ans[ai].rdata.srv_record.port = recs[ri].data.srv.wPort;
 346                         ans[ai].rdata.srv_record.target = recs[ri].data.srv.nameTarget;
 347                         ai++;
 348                 }
 349                 break;
 350         case DNS_QTYPE_SOA:
 351                 for (ri = 0; ri < el->num_values; ri++) {
 352                         if (recs[ri].wType != question->question_type) {
 353                                 continue;
 354                         }
 355
 356                         ZERO_STRUCT(ans[ai]);
 357                         ans[ai].name = question->name;
 358                         ans[ai].rr_type = DNS_QTYPE_SOA;
 359                         ans[ai].rr_class = DNS_QCLASS_IP;
 360                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 361                         ans[ai].length = UINT16_MAX;
 362                         ans[ai].rdata.soa_record.mname  = recs[ri].data.soa.mname;
 363                         ans[ai].rdata.soa_record.rname  = recs[ri].data.soa.rname;
 364                         ans[ai].rdata.soa_record.serial = recs[ri].data.soa.serial;
 365                         ans[ai].rdata.soa_record.refresh= recs[ri].data.soa.refresh;
 366                         ans[ai].rdata.soa_record.retry  = recs[ri].data.soa.retry;
 367                         ans[ai].rdata.soa_record.expire = recs[ri].data.soa.expire;
 368                         ans[ai].rdata.soa_record.minimum= recs[ri].data.soa.minimum;
 369                         ai++;
 370                 }
 371                 break;
 372         default:
 373                 return NT_STATUS_NOT_IMPLEMENTED;
 374         }
 375
 376         if (*ancount == ai) {
 377                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 378         }
 379
 380         *ancount = ai;
 381         *answers = ans;
 382
 383         return NT_STATUS_OK;
 384
 385 }
 386
 387 static NTSTATUS dns_server_process_query(struct dns_server *dns,
 388                                          TALLOC_CTX *mem_ctx,
 389                                          struct dns_name_packet *in,
 390                                          struct dns_res_rec **answers,    uint16_t *ancount,
 391                                          struct dns_res_rec **nsrecs,     uint16_t *nscount,
 392                                          struct dns_res_rec **additional, uint16_t *arcount)
 393 {
 394         uint16_t num_answers=0;
 395         struct dns_res_rec *ans=NULL;
 396         int i;
 397         NTSTATUS status;
 398
 399         ans = talloc_array(mem_ctx, struct dns_res_rec, 0);
 400         if (answers == NULL) return NT_STATUS_NO_MEMORY;
 401
 402         for (i = 0; i < in->qdcount; ++i) {
 403                 status = handle_question(dns, mem_ctx, &in->questions[i], &ans, &num_answers);
 404                 NT_STATUS_NOT_OK_RETURN(status);
 405         }
 406
 407         *answers = ans;
 408         *ancount = num_answers;
 409
 410         /*FIXME: Do something for these */
 411         *nsrecs  = NULL;
 412         *nscount = 0;
 413
 414         *additional = NULL;
 415         *arcount    = 0;
 416
 417         return NT_STATUS_OK;
 418 }
 419
 420 static NTSTATUS dns_server_process_update(struct dns_server *dns,
 421                                           TALLOC_CTX *mem_ctx,
 422                                           struct dns_name_packet *in,
 423                                           struct dns_res_rec **prereqs,    uint16_t *prereq_count,
 424                                           struct dns_res_rec **updates,    uint16_t *update_count,
 425                                           struct dns_res_rec **additional, uint16_t *arcount)
 426 {
 427         struct dns_name_question *zone;
 428
 429         if (in->qdcount != 1) {
 430                 return NT_STATUS_NOT_IMPLEMENTED;
 431         }
 432
 433         zone = in->questions;
 434
 435         DEBUG(0, ("Got a dns update request.\n"));
 436
 437
 438         return NT_STATUS_NOT_IMPLEMENTED;
 439 }
 440
 441 static NTSTATUS dns_process(struct dns_server *dns,
 442                             TALLOC_CTX *mem_ctx,
 443                             DATA_BLOB *in,
 444                             DATA_BLOB *out)
 445 {
 446         enum ndr_err_code ndr_err;
 447         NTSTATUS ret;
 448         struct dns_name_packet *in_packet;
 449         struct dns_name_packet *out_packet;
 450         struct dns_res_rec *answers = NULL, *nsrecs = NULL, *additional = NULL;
 451         uint16_t num_answers = 0 , num_nsrecs = 0, num_additional = 0;
 452         uint16_t reply_code;
 453
 454         if (in->length < 12) {
 455                 return NT_STATUS_INVALID_PARAMETER;
 456         }
 457
 458         in_packet = talloc_zero(mem_ctx, struct dns_name_packet);
 459         /* TODO: We don't really need an out_packet. */
 460         out_packet = talloc_zero(mem_ctx, struct dns_name_packet);
 461
 462         if (in_packet == NULL) return NT_STATUS_NO_MEMORY;
 463         if (out_packet == NULL) return NT_STATUS_NO_MEMORY;
 464
 465         dump_data(2, in->data, in->length);
 466
 467         ndr_err = ndr_pull_struct_blob(in, in_packet, in_packet,
 468                         (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 469         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 470                 TALLOC_FREE(in_packet);
 471                 DEBUG(0, ("Failed to parse packet %d!\n", ndr_err));
 472                 *out = *in;
 473
 474                 out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
 475                 out->data[3] |= DNS_RCODE_FORMERR;
 476
 477                 return NT_STATUS_OK;
 478         }
 479
 480         NDR_PRINT_DEBUG(dns_name_packet, in_packet);
 481         *out_packet = *in_packet;
 482         out_packet->operation |= DNS_FLAG_REPLY;
 483
 484         switch (in_packet->operation & DNS_OPCODE) {
 485         case DNS_OPCODE_QUERY:
 486
 487                 ret = dns_server_process_query(dns, out_packet, in_packet,
 488                                                &answers, &num_answers,
 489                                                &nsrecs,  &num_nsrecs,
 490                                                &additional, &num_additional);
 491                 reply_code = DNS_RCODE_NXDOMAIN;
 492
 493                 break;
 494         case DNS_OPCODE_REGISTER:
 495                 ret = dns_server_process_update(dns, out_packet, in_packet,
 496                                                 &answers, &num_answers,
 497                                                 &nsrecs,  &num_nsrecs,
 498                                                 &additional, &num_additional);
 499                 reply_code = ntstatus_to_dns_err(ret);
 500                 break;
 501         default:
 502                 ret = NT_STATUS_NOT_IMPLEMENTED;
 503                 reply_code = DNS_RCODE_NOTIMP;
 504                 break;
 505         }
 506
 507         if (NT_STATUS_IS_OK(ret)) {
 508                 out_packet->ancount = num_answers;
 509                 out_packet->answers = answers;
 510
 511                 out_packet->nscount = num_nsrecs;
 512                 out_packet->nsrecs  = nsrecs;
 513
 514                 out_packet->arcount = num_additional;
 515                 out_packet->additional = additional;
 516         } else {
 517                 out_packet->operation |= reply_code;
 518         }
 519
 520         NDR_PRINT_DEBUG(dns_name_packet, out_packet);
 521         ndr_err = ndr_push_struct_blob(out, out_packet, out_packet,
 522                         (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 523         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 524                 TALLOC_FREE(in_packet);
 525                 TALLOC_FREE(out_packet);
 526                 DEBUG(0, ("Failed to push packet %d!\n", ndr_err));
 527                 *out = *in;
 528
 529                 out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
 530                 out->data[3] |= DNS_RCODE_SERVFAIL;
 531
 532                 return NT_STATUS_OK;
 533         }
 534
 535         dump_data(2, out->data, out->length);
 536         return NT_STATUS_OK;
 537 }
 538
 539 struct dns_tcp_call {
 540         struct dns_tcp_connection *dns_conn;
 541         DATA_BLOB in;
 542         DATA_BLOB out;
 543         uint8_t out_hdr[4];
 544         struct iovec out_iov[2];
 545 };
 546
 547 static void dns_tcp_call_writev_done(struct tevent_req *subreq);
 548
 549 static void dns_tcp_call_loop(struct tevent_req *subreq)
 550 {
 551         struct dns_tcp_connection *dns_conn = tevent_req_callback_data(subreq,
 552                                       struct dns_tcp_connection);
 553         struct dns_tcp_call *call;
 554         NTSTATUS status;
 555
 556         call = talloc(dns_conn, struct dns_tcp_call);
 557         if (call == NULL) {
 558                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 559                                 "no memory for dns_tcp_call");
 560                 return;
 561         }
 562         call->dns_conn = dns_conn;
 563
 564         status = tstream_read_pdu_blob_recv(subreq,
 565                                             call,
 566                                             &call->in);
 567         TALLOC_FREE(subreq);
 568         if (!NT_STATUS_IS_OK(status)) {
 569                 const char *reason;
 570
 571                 reason = talloc_asprintf(call, "dns_tcp_call_loop: "
 572                                          "tstream_read_pdu_blob_recv() - %s",
 573                                          nt_errstr(status));
 574                 if (!reason) {
 575                         reason = nt_errstr(status);
 576                 }
 577
 578                 dns_tcp_terminate_connection(dns_conn, reason);
 579                 return;
 580         }
 581
 582         DEBUG(10,("Received krb5 TCP packet of length %lu from %s\n",
 583                  (long) call->in.length,
 584                  tsocket_address_string(dns_conn->conn->remote_address, call)));
 585
 586         /* skip length header */
 587         call->in.data +=4;
 588         call->in.length -= 4;
 589
 590         /* Call dns */
 591         status = dns_process(dns_conn->dns_socket->dns, call, &call->in, &call->out);
 592         if (!NT_STATUS_IS_OK(status)) {
 593                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 594                 dns_tcp_terminate_connection(dns_conn,
 595                                 "dns_tcp_call_loop: process function failed");
 596                 return;
 597         }
 598
 599         /* First add the length of the out buffer */
 600         RSIVAL(call->out_hdr, 0, call->out.length);
 601         call->out_iov[0].iov_base = (char *) call->out_hdr;
 602         call->out_iov[0].iov_len = 4;
 603
 604         call->out_iov[1].iov_base = (char *) call->out.data;
 605         call->out_iov[1].iov_len = call->out.length;
 606
 607         subreq = tstream_writev_queue_send(call,
 608                                            dns_conn->conn->event.ctx,
 609                                            dns_conn->tstream,
 610                                            dns_conn->send_queue,
 611                                            call->out_iov, 2);
 612         if (subreq == NULL) {
 613                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 614                                 "no memory for tstream_writev_queue_send");
 615                 return;
 616         }
 617         tevent_req_set_callback(subreq, dns_tcp_call_writev_done, call);
 618
 619         /*
 620          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 621          * packet_full_request_u32 provides the pdu length then.
 622          */
 623         subreq = tstream_read_pdu_blob_send(dns_conn,
 624                                             dns_conn->conn->event.ctx,
 625                                             dns_conn->tstream,
 626                                             4, /* initial_read_size */
 627                                             packet_full_request_u32,
 628                                             dns_conn);
 629         if (subreq == NULL) {
 630                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 631                                 "no memory for tstream_read_pdu_blob_send");
 632                 return;
 633         }
 634         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 635 }
 636
 637 static void dns_tcp_call_writev_done(struct tevent_req *subreq)
 638 {
 639         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
 640                         struct dns_tcp_call);
 641         int sys_errno;
 642         int rc;
 643
 644         rc = tstream_writev_queue_recv(subreq, &sys_errno);
 645         TALLOC_FREE(subreq);
 646         if (rc == -1) {
 647                 const char *reason;
 648
 649                 reason = talloc_asprintf(call, "dns_tcp_call_writev_done: "
 650                                          "tstream_writev_queue_recv() - %d:%s",
 651                                          sys_errno, strerror(sys_errno));
 652                 if (!reason) {
 653                         reason = "dns_tcp_call_writev_done: tstream_writev_queue_recv() failed";
 654                 }
 655
 656                 dns_tcp_terminate_connection(call->dns_conn, reason);
 657                 return;
 658         }
 659
 660         /* We don't care about errors */
 661
 662         talloc_free(call);
 663 }
 664
 665 /*
 666   called when we get a new connection
 667 */
 668 static void dns_tcp_accept(struct stream_connection *conn)
 669 {
 670         struct dns_socket *dns_socket;
 671         struct dns_tcp_connection *dns_conn;
 672         struct tevent_req *subreq;
 673         int rc;
 674
 675         dns_conn = talloc_zero(conn, struct dns_tcp_connection);
 676         if (dns_conn == NULL) {
 677                 stream_terminate_connection(conn,
 678                                 "dns_tcp_accept: out of memory");
 679                 return;
 680         }
 681
 682         dns_conn->send_queue = tevent_queue_create(conn, "dns_tcp_accept");
 683         if (dns_conn->send_queue == NULL) {
 684                 stream_terminate_connection(conn,
 685                                 "dns_tcp_accept: out of memory");
 686                 return;
 687         }
 688
 689         dns_socket = talloc_get_type(conn->private_data, struct dns_socket);
 690
 691         TALLOC_FREE(conn->event.fde);
 692
 693         rc = tstream_bsd_existing_socket(dns_conn,
 694                         socket_get_fd(conn->socket),
 695                         &dns_conn->tstream);
 696         if (rc < 0) {
 697                 stream_terminate_connection(conn,
 698                                 "dns_tcp_accept: out of memory");
 699                 return;
 700         }
 701
 702         dns_conn->conn = conn;
 703         dns_conn->dns_socket = dns_socket;
 704         conn->private_data = dns_conn;
 705
 706         /*
 707          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 708          * packet_full_request_u32 provides the pdu length then.
 709          */
 710         subreq = tstream_read_pdu_blob_send(dns_conn,
 711                                             dns_conn->conn->event.ctx,
 712                                             dns_conn->tstream,
 713                                             4, /* initial_read_size */
 714                                             packet_full_request_u32,
 715                                             dns_conn);
 716         if (subreq == NULL) {
 717                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_accept: "
 718                                 "no memory for tstream_read_pdu_blob_send");
 719                 return;
 720         }
 721         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 722 }
 723
 724 static const struct stream_server_ops dns_tcp_stream_ops = {
 725         .name                   = "dns_tcp",
 726         .accept_connection      = dns_tcp_accept,
 727         .recv_handler           = dns_tcp_recv,
 728         .send_handler           = dns_tcp_send
 729 };
 730
 731 struct dns_udp_call {
 732         struct tsocket_address *src;
 733         DATA_BLOB in;
 734         DATA_BLOB out;
 735 };
 736
 737 static void dns_udp_call_sendto_done(struct tevent_req *subreq);
 738
 739 static void dns_udp_call_loop(struct tevent_req *subreq)
 740 {
 741         struct dns_udp_socket *sock = tevent_req_callback_data(subreq,
 742                                       struct dns_udp_socket);
 743         struct dns_udp_call *call;
 744         uint8_t *buf;
 745         ssize_t len;
 746         int sys_errno;
 747         NTSTATUS status;
 748
 749         call = talloc(sock, struct dns_udp_call);
 750         if (call == NULL) {
 751                 talloc_free(call);
 752                 goto done;
 753         }
 754
 755         len = tdgram_recvfrom_recv(subreq, &sys_errno,
 756                                    call, &buf, &call->src);
 757         TALLOC_FREE(subreq);
 758         if (len == -1) {
 759                 talloc_free(call);
 760                 goto done;
 761         }
 762
 763         call->in.data = buf;
 764         call->in.length = len;
 765
 766         DEBUG(10,("Received krb5 UDP packet of length %lu from %s\n",
 767                  (long)call->in.length,
 768                  tsocket_address_string(call->src, call)));
 769
 770         /* Call krb5 */
 771         status = dns_process(sock->dns_socket->dns, call, &call->in, &call->out);
 772         if (!NT_STATUS_IS_OK(status)) {
 773                 talloc_free(call);
 774                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 775                 goto done;
 776         }
 777
 778         subreq = tdgram_sendto_queue_send(call,
 779                                           sock->dns_socket->dns->task->event_ctx,
 780                                           sock->dgram,
 781                                           sock->send_queue,
 782                                           call->out.data,
 783                                           call->out.length,
 784                                           call->src);
 785         if (subreq == NULL) {
 786                 talloc_free(call);
 787                 goto done;
 788         }
 789         tevent_req_set_callback(subreq, dns_udp_call_sendto_done, call);
 790
 791 done:
 792         subreq = tdgram_recvfrom_send(sock,
 793                                       sock->dns_socket->dns->task->event_ctx,
 794                                       sock->dgram);
 795         if (subreq == NULL) {
 796                 task_server_terminate(sock->dns_socket->dns->task,
 797                                       "no memory for tdgram_recvfrom_send",
 798                                       true);
 799                 return;
 800         }
 801         tevent_req_set_callback(subreq, dns_udp_call_loop, sock);
 802 }
 803
 804 static void dns_udp_call_sendto_done(struct tevent_req *subreq)
 805 {
 806         struct dns_udp_call *call = tevent_req_callback_data(subreq,
 807                                        struct dns_udp_call);
 808         ssize_t ret;
 809         int sys_errno;
 810
 811         ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
 812
 813         /* We don't care about errors */
 814
 815         talloc_free(call);
 816 }
 817
 818 /*
 819   start listening on the given address
 820 */
 821 static NTSTATUS dns_add_socket(struct dns_server *dns,
 822                                const struct model_ops *model_ops,
 823                                const char *name,
 824                                const char *address,
 825                                uint16_t port)
 826 {
 827         struct dns_socket *dns_socket;
 828         struct dns_udp_socket *dns_udp_socket;
 829         struct tevent_req *udpsubreq;
 830         NTSTATUS status;
 831         int ret;
 832
 833         dns_socket = talloc(dns, struct dns_socket);
 834         NT_STATUS_HAVE_NO_MEMORY(dns_socket);
 835
 836         dns_socket->dns = dns;
 837
 838         ret = tsocket_address_inet_from_strings(dns_socket, "ip",
 839                                                 address, port,
 840                                                 &dns_socket->local_address);
 841         if (ret != 0) {
 842                 status = map_nt_error_from_unix(errno);
 843                 return status;
 844         }
 845
 846         status = stream_setup_socket(dns->task->event_ctx,
 847                                      dns->task->lp_ctx,
 848                                      model_ops,
 849                                      &dns_tcp_stream_ops,
 850                                      "ip", address, &port,
 851                                      lpcfg_socket_options(dns->task->lp_ctx),
 852                                      dns_socket);
 853         if (!NT_STATUS_IS_OK(status)) {
 854                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 855                          address, port, nt_errstr(status)));
 856                 talloc_free(dns_socket);
 857                 return status;
 858         }
 859
 860         dns_udp_socket = talloc(dns_socket, struct dns_udp_socket);
 861         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket);
 862
 863         dns_udp_socket->dns_socket = dns_socket;
 864
 865         ret = tdgram_inet_udp_socket(dns_socket->local_address,
 866                                      NULL,
 867                                      dns_udp_socket,
 868                                      &dns_udp_socket->dgram);
 869         if (ret != 0) {
 870                 status = map_nt_error_from_unix(errno);
 871                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
 872                          address, port, nt_errstr(status)));
 873                 return status;
 874         }
 875
 876         dns_udp_socket->send_queue = tevent_queue_create(dns_udp_socket,
 877                                                          "dns_udp_send_queue");
 878         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket->send_queue);
 879
 880         udpsubreq = tdgram_recvfrom_send(dns_udp_socket,
 881                                          dns->task->event_ctx,
 882                                          dns_udp_socket->dgram);
 883         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
 884         tevent_req_set_callback(udpsubreq, dns_udp_call_loop, dns_udp_socket);
 885
 886         return NT_STATUS_OK;
 887 }
 888
 889 /*
 890   setup our listening sockets on the configured network interfaces
 891 */
 892 static NTSTATUS dns_startup_interfaces(struct dns_server *dns, struct loadparm_context *lp_ctx,
 893                                        struct interface *ifaces)
 894 {
 895         const struct model_ops *model_ops;
 896         int num_interfaces;
 897         TALLOC_CTX *tmp_ctx = talloc_new(dns);
 898         NTSTATUS status;
 899         int i;
 900
 901         /* within the dns task we want to be a single process, so
 902            ask for the single process model ops and pass these to the
 903            stream_setup_socket() call. */
 904         model_ops = process_model_startup(dns->task->event_ctx, "single");
 905         if (!model_ops) {
 906                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 907                 return NT_STATUS_INTERNAL_ERROR;
 908         }
 909
 910         num_interfaces = iface_count(ifaces);
 911
 912         for (i=0; i<num_interfaces; i++) {
 913                 const char *address = talloc_strdup(tmp_ctx, iface_n_ip(ifaces, i));
 914
 915                 status = dns_add_socket(dns, model_ops, "dns", address, DNS_SERVICE_PORT);
 916                 NT_STATUS_NOT_OK_RETURN(status);
 917         }
 918
 919         talloc_free(tmp_ctx);
 920
 921         return NT_STATUS_OK;
 922 }
 923
 924 static int dns_server_sort_zones(struct ldb_message **m1, struct ldb_message **m2)
 925 {
 926         const char *n1, *n2;
 927         size_t l1, l2;
 928
 929         n1 = ldb_msg_find_attr_as_string(*m1, "name", NULL);
 930         n2 = ldb_msg_find_attr_as_string(*m2, "name", NULL);
 931
 932         l1 = strlen(n1);
 933         l2 = strlen(n2);
 934
 935         /* If the string lengths are not equal just sort by length */
 936         if (l1 != l2) {
 937                 /* If m1 is the larger zone name, return it first */
 938                 return l2 - l1;
 939         }
 940
 941         /*TODO: We need to compare DNs here, we want the DomainDNSZones first */
 942         return 0;
 943 }
 944
 945 static void dns_task_init(struct task_server *task)
 946 {
 947         struct dns_server *dns;
 948         NTSTATUS status;
 949         struct interface *ifaces;
 950         int ret;
 951         struct ldb_result *res;
 952         struct ldb_dn *rootdn;
 953         static const char * const attrs[] = { "name", NULL};
 954         int i;
 955
 956
 957         switch (lpcfg_server_role(task->lp_ctx)) {
 958         case ROLE_STANDALONE:
 959                 task_server_terminate(task, "dns: no DNS required in standalone configuration", false);
 960                 return;
 961         case ROLE_DOMAIN_MEMBER:
 962                 task_server_terminate(task, "dns: no DNS required in member server configuration", false);
 963                 return;
 964         case ROLE_DOMAIN_CONTROLLER:
 965                 /* Yes, we want a DNS */
 966                 break;
 967         }
 968
 969         load_interfaces(task, lpcfg_interfaces(task->lp_ctx), &ifaces);
 970
 971         if (iface_count(ifaces) == 0) {
 972                 task_server_terminate(task, "dns: no network interfaces configured", false);
 973                 return;
 974         }
 975
 976         task_server_set_title(task, "task[dns]");
 977
 978         dns = talloc_zero(task, struct dns_server);
 979         if (dns == NULL) {
 980                 task_server_terminate(task, "dns: out of memory", true);
 981                 return;
 982         }
 983
 984         dns->task = task;
 985
 986         dns->samdb = samdb_connect(dns, dns->task->event_ctx, dns->task->lp_ctx,
 987                               system_session(dns->task->lp_ctx), 0);
 988         if (!dns->samdb) {
 989                 task_server_terminate(task, "dns: samdb_connect failed", true);
 990                 return;
 991         }
 992
 993         rootdn = ldb_dn_new(dns, dns->samdb, "");
 994         if (rootdn == NULL) {
 995                 task_server_terminate(task, "dns: out of memory", true);
 996                 return;
 997         }
 998
 999         // TODO: this search does not work against windows
1000         ret = dsdb_search(dns->samdb, dns, &res, rootdn, LDB_SCOPE_SUBTREE,
1001                           attrs, DSDB_SEARCH_SEARCH_ALL_PARTITIONS, "(objectClass=dnsZone)");
1002         if (ret != LDB_SUCCESS) {
1003                 task_server_terminate(task,
1004                                       "dns: failed to look up root DNS zones",
1005                                       true);
1006                 return;
1007         }
1008
1009         TYPESAFE_QSORT(res->msgs, res->count, dns_server_sort_zones);
1010
1011         for (i=0; i < res->count; i++) {
1012                 struct dns_server_zone *z;
1013
1014                 z = talloc_zero(dns, struct dns_server_zone);
1015                 if (z == NULL) {
1016                 }
1017
1018                 z->name = ldb_msg_find_attr_as_string(res->msgs[i], "name", NULL);
1019                 z->dn = talloc_move(z, &res->msgs[i]->dn);
1020
1021                 DLIST_ADD_END(dns->zones, z, NULL);
1022         }
1023
1024         status = dns_startup_interfaces(dns, task->lp_ctx, ifaces);
1025         if (!NT_STATUS_IS_OK(status)) {
1026                 task_server_terminate(task, "dns failed to setup interfaces", true);
1027                 return;
1028         }
1029 }
1030
1031 NTSTATUS server_service_dns_init(void)
1032 {
1033         return register_server_service("dns", dns_task_init);
1034 }