source4/dns_server/dns_query.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    DNS server handler for queries
   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 "libcli/util/werror.h"
  25 #include "librpc/ndr/libndr.h"
  26 #include "librpc/gen_ndr/ndr_dns.h"
  27 #include "librpc/gen_ndr/ndr_dnsp.h"
  28 #include <ldb.h>
  29 #include "param/param.h"
  30 #include "dsdb/samdb/samdb.h"
  31 #include "dsdb/common/util.h"
  32 #include "dns_server/dns_server.h"
  33 #include "libcli/dns/libdns.h"
  34 #include "lib/util/util_net.h"
  35 #include "lib/util/tevent_werror.h"
  36 #include "auth/auth.h"
  37 #include "auth/credentials/credentials.h"
  38 #include "auth/gensec/gensec.h"
  39
  40 static WERROR create_response_rr(const struct dns_name_question *question,
  41                                  const struct dnsp_DnssrvRpcRecord *rec,
  42                                  struct dns_res_rec **answers, uint16_t *ancount)
  43 {
  44         struct dns_res_rec *ans = *answers;
  45         uint16_t ai = *ancount;
  46         char *tmp;
  47         uint32_t i;
  48
  49         ZERO_STRUCT(ans[ai]);
  50
  51         switch (rec->wType) {
  52         case DNS_QTYPE_CNAME:
  53                 ans[ai].rdata.cname_record = talloc_strdup(ans, rec->data.cname);
  54                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.cname_record);
  55                 break;
  56         case DNS_QTYPE_A:
  57                 ans[ai].rdata.ipv4_record = talloc_strdup(ans, rec->data.ipv4);
  58                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ipv4_record);
  59                 break;
  60         case DNS_QTYPE_AAAA:
  61                 ans[ai].rdata.ipv6_record = talloc_strdup(ans, rec->data.ipv6);
  62                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ipv6_record);
  63                 break;
  64         case DNS_TYPE_NS:
  65                 ans[ai].rdata.ns_record = talloc_strdup(ans, rec->data.ns);
  66                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ns_record);
  67                 break;
  68         case DNS_QTYPE_SRV:
  69                 ans[ai].rdata.srv_record.priority = rec->data.srv.wPriority;
  70                 ans[ai].rdata.srv_record.weight   = rec->data.srv.wWeight;
  71                 ans[ai].rdata.srv_record.port     = rec->data.srv.wPort;
  72                 ans[ai].rdata.srv_record.target   = talloc_strdup(
  73                         ans, rec->data.srv.nameTarget);
  74                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.srv_record.target);
  75                 break;
  76         case DNS_QTYPE_SOA:
  77                 ans[ai].rdata.soa_record.mname   = talloc_strdup(
  78                         ans, rec->data.soa.mname);
  79                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.soa_record.mname);
  80                 ans[ai].rdata.soa_record.rname   = talloc_strdup(
  81                         ans, rec->data.soa.rname);
  82                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.soa_record.rname);
  83                 ans[ai].rdata.soa_record.serial  = rec->data.soa.serial;
  84                 ans[ai].rdata.soa_record.refresh = rec->data.soa.refresh;
  85                 ans[ai].rdata.soa_record.retry   = rec->data.soa.retry;
  86                 ans[ai].rdata.soa_record.expire  = rec->data.soa.expire;
  87                 ans[ai].rdata.soa_record.minimum = rec->data.soa.minimum;
  88                 break;
  89         case DNS_QTYPE_PTR:
  90                 ans[ai].rdata.ptr_record = talloc_strdup(ans, rec->data.ptr);
  91                 break;
  92         case DNS_QTYPE_TXT:
  93                 tmp = talloc_asprintf(ans, "\"%s\"", rec->data.txt.str[0]);
  94                 W_ERROR_HAVE_NO_MEMORY(tmp);
  95                 for (i=1; i<rec->data.txt.count; i++) {
  96                         tmp = talloc_asprintf_append_buffer(
  97                                 tmp, " \"%s\"", rec->data.txt.str[i]);
  98                         W_ERROR_HAVE_NO_MEMORY(tmp);
  99                 }
 100                 ans[ai].rdata.txt_record.txt = tmp;
 101                 break;
 102         default:
 103                 DEBUG(0, ("Got unhandled type %u query.\n", rec->wType));
 104                 return DNS_ERR(NOT_IMPLEMENTED);
 105         }
 106
 107         ans[ai].name = talloc_strdup(ans, question->name);
 108         W_ERROR_HAVE_NO_MEMORY(ans[ai].name);
 109         ans[ai].rr_type = rec->wType;
 110         ans[ai].rr_class = DNS_QCLASS_IN;
 111         ans[ai].ttl = rec->dwTtlSeconds;
 112         ans[ai].length = UINT16_MAX;
 113         ai++;
 114
 115         *answers = ans;
 116         *ancount = ai;
 117
 118         return WERR_OK;
 119 }
 120
 121 struct ask_forwarder_state {
 122         struct tevent_context *ev;
 123         uint16_t id;
 124         struct dns_name_packet in_packet;
 125 };
 126
 127 static void ask_forwarder_done(struct tevent_req *subreq);
 128
 129 static struct tevent_req *ask_forwarder_send(
 130         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 131         const char *forwarder, struct dns_name_question *question)
 132 {
 133         struct tevent_req *req, *subreq;
 134         struct ask_forwarder_state *state;
 135         struct dns_name_packet out_packet = { 0, };
 136         DATA_BLOB out_blob;
 137         enum ndr_err_code ndr_err;
 138
 139         req = tevent_req_create(mem_ctx, &state, struct ask_forwarder_state);
 140         if (req == NULL) {
 141                 return NULL;
 142         }
 143         state->ev = ev;
 144         generate_random_buffer((uint8_t *)&state->id, sizeof(state->id));
 145
 146         if (!is_ipaddress(forwarder)) {
 147                 DEBUG(0, ("Invalid 'dns forwarder' setting '%s', needs to be "
 148                           "an IP address\n", forwarder));
 149                 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 150                 return tevent_req_post(req, ev);
 151         }
 152
 153         out_packet.id = state->id;
 154         out_packet.operation |= DNS_OPCODE_QUERY | DNS_FLAG_RECURSION_DESIRED;
 155         out_packet.qdcount = 1;
 156         out_packet.questions = question;
 157
 158         ndr_err = ndr_push_struct_blob(
 159                 &out_blob, state, &out_packet,
 160                 (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 161         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 162                 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
 163                 return tevent_req_post(req, ev);
 164         }
 165         subreq = dns_udp_request_send(state, ev, forwarder, out_blob.data,
 166                                       out_blob.length);
 167         if (tevent_req_nomem(subreq, req)) {
 168                 return tevent_req_post(req, ev);
 169         }
 170         tevent_req_set_callback(subreq, ask_forwarder_done, req);
 171         return req;
 172 }
 173
 174 static void ask_forwarder_done(struct tevent_req *subreq)
 175 {
 176         struct tevent_req *req = tevent_req_callback_data(
 177                 subreq, struct tevent_req);
 178         struct ask_forwarder_state *state = tevent_req_data(
 179                 req, struct ask_forwarder_state);
 180         DATA_BLOB in_blob;
 181         enum ndr_err_code ndr_err;
 182         WERROR ret;
 183
 184         ret = dns_udp_request_recv(subreq, state,
 185                                    &in_blob.data, &in_blob.length);
 186         TALLOC_FREE(subreq);
 187         if (tevent_req_werror(req, ret)) {
 188                 return;
 189         }
 190
 191         ndr_err = ndr_pull_struct_blob(
 192                 &in_blob, state, &state->in_packet,
 193                 (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 194         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 195                 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
 196                 return;
 197         }
 198         if (state->in_packet.id != state->id) {
 199                 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 200                 return;
 201         }
 202         tevent_req_done(req);
 203 }
 204
 205 static WERROR ask_forwarder_recv(
 206         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 207         struct dns_res_rec **answers, uint16_t *ancount,
 208         struct dns_res_rec **nsrecs, uint16_t *nscount,
 209         struct dns_res_rec **additional, uint16_t *arcount)
 210 {
 211         struct ask_forwarder_state *state = tevent_req_data(
 212                 req, struct ask_forwarder_state);
 213         struct dns_name_packet *in_packet = &state->in_packet;
 214         WERROR err;
 215
 216         if (tevent_req_is_werror(req, &err)) {
 217                 return err;
 218         }
 219
 220         *ancount = in_packet->ancount;
 221         *answers = talloc_move(mem_ctx, &in_packet->answers);
 222
 223         *nscount = in_packet->nscount;
 224         *nsrecs = talloc_move(mem_ctx, &in_packet->nsrecs);
 225
 226         *arcount = in_packet->arcount;
 227         *additional = talloc_move(mem_ctx, &in_packet->additional);
 228
 229         return WERR_OK;
 230 }
 231
 232 static WERROR handle_question(struct dns_server *dns,
 233                               TALLOC_CTX *mem_ctx,
 234                               const struct dns_name_question *question,
 235                               struct dns_res_rec **answers, uint16_t *ancount)
 236 {
 237         struct dns_res_rec *ans = *answers;
 238         WERROR werror;
 239         unsigned int ri;
 240         struct dnsp_DnssrvRpcRecord *recs;
 241         uint16_t rec_count, ai = *ancount;
 242         struct ldb_dn *dn = NULL;
 243
 244         werror = dns_name2dn(dns, mem_ctx, question->name, &dn);
 245         W_ERROR_NOT_OK_RETURN(werror);
 246
 247         werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rec_count);
 248         W_ERROR_NOT_OK_RETURN(werror);
 249
 250         ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec, rec_count + ai);
 251         if (ans == NULL) {
 252                 return WERR_NOMEM;
 253         }
 254
 255         for (ri = 0; ri < rec_count; ri++) {
 256                 if ((recs[ri].wType == DNS_TYPE_CNAME) &&
 257                     ((question->question_type == DNS_QTYPE_A) ||
 258                      (question->question_type == DNS_QTYPE_AAAA))) {
 259                         struct dns_name_question *new_q =
 260                                 talloc(mem_ctx, struct dns_name_question);
 261
 262                         if (new_q == NULL) {
 263                                 return WERR_NOMEM;
 264                         }
 265
 266                         /* We reply with one more record, so grow the array */
 267                         ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec,
 268                                              rec_count + 1);
 269                         if (ans == NULL) {
 270                                 TALLOC_FREE(new_q);
 271                                 return WERR_NOMEM;
 272                         }
 273
 274                         /* First put in the CNAME record */
 275                         werror = create_response_rr(question, &recs[ri], &ans, &ai);
 276                         if (!W_ERROR_IS_OK(werror)) {
 277                                 return werror;
 278                         }
 279
 280                         /* And then look up the name it points at.. */
 281
 282                         /* First build up the new question */
 283                         new_q->question_type = question->question_type;
 284                         new_q->question_class = question->question_class;
 285                         if (new_q->question_type == DNS_QTYPE_A) {
 286                                 new_q->name = talloc_strdup(new_q, recs[ri].data.ipv4);
 287                         } else if (new_q->question_type == DNS_QTYPE_AAAA) {
 288                                 new_q->name = talloc_strdup(new_q, recs[ri].data.ipv6);
 289                         }
 290                         if (new_q->name == NULL) {
 291                                 TALLOC_FREE(new_q);
 292                                 return WERR_NOMEM;
 293                         }
 294                         /* and then call the lookup again */
 295                         werror = handle_question(dns, mem_ctx, new_q, &ans, &ai);
 296                         if (!W_ERROR_IS_OK(werror)) {
 297                                 return werror;
 298                         }
 299
 300
 301                         continue;
 302                 }
 303                 if ((question->question_type != DNS_QTYPE_ALL) &&
 304                     (recs[ri].wType != question->question_type)) {
 305                         continue;
 306                 }
 307                 werror = create_response_rr(question, &recs[ri], &ans, &ai);
 308                 if (!W_ERROR_IS_OK(werror)) {
 309                         return werror;
 310                 }
 311         }
 312
 313         if (ai == 0) {
 314                 return DNS_ERR(NAME_ERROR);
 315         }
 316
 317         *ancount = ai;
 318         *answers = ans;
 319
 320         return WERR_OK;
 321 }
 322
 323 static NTSTATUS create_tkey(struct dns_server *dns,
 324                             const char* name,
 325                             struct dns_server_tkey **tkey)
 326 {
 327         NTSTATUS status;
 328         struct dns_server_tkey_store *store = dns->tkeys;
 329         struct dns_server_tkey *k = talloc_zero(store, struct dns_server_tkey);
 330
 331         if (k == NULL) {
 332                 return NT_STATUS_NO_MEMORY;
 333         }
 334
 335         k->name = talloc_strdup(k, name);
 336
 337         if (k->name  == NULL) {
 338                 return NT_STATUS_NO_MEMORY;
 339         }
 340
 341         status = samba_server_gensec_start(k,
 342                                            dns->task->event_ctx,
 343                                            dns->task->msg_ctx,
 344                                            dns->task->lp_ctx,
 345                                            dns->server_credentials,
 346                                            "dns",
 347                                            &k->gensec);
 348         if (!NT_STATUS_IS_OK(status)) {
 349                 DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
 350                 *tkey = NULL;
 351                 return status;
 352         }
 353
 354         gensec_want_feature(k->gensec, GENSEC_FEATURE_SIGN);
 355
 356         status = gensec_start_mech_by_oid(k->gensec, GENSEC_OID_SPNEGO);
 357
 358         if (!NT_STATUS_IS_OK(status)) {
 359                 DEBUG(1, ("Failed to start GENSEC server code: %s\n",
 360                           nt_errstr(status)));
 361                 *tkey = NULL;
 362                 return status;
 363         }
 364
 365         if (store->tkeys[store->next_idx] != NULL) {
 366                 TALLOC_FREE(store->tkeys[store->next_idx]);
 367         }
 368
 369         store->tkeys[store->next_idx] = k;
 370         (store->next_idx)++;
 371         store->next_idx %= store->size;
 372
 373         *tkey = k;
 374         return NT_STATUS_OK;
 375 }
 376
 377 static NTSTATUS accept_gss_ticket(TALLOC_CTX *mem_ctx,
 378                                   struct dns_server *dns,
 379                                   struct dns_server_tkey *tkey,
 380                                   const DATA_BLOB *key,
 381                                   DATA_BLOB *reply,
 382                                   uint16_t *dns_auth_error)
 383 {
 384         NTSTATUS status;
 385
 386         status = gensec_update(tkey->gensec, mem_ctx, dns->task->event_ctx,
 387                                *key, reply);
 388
 389         if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
 390                 *dns_auth_error = DNS_RCODE_OK;
 391                 return status;
 392         }
 393
 394         if (NT_STATUS_IS_OK(status)) {
 395
 396                 status = gensec_session_info(tkey->gensec, tkey, &tkey->session_info);
 397                 if (!NT_STATUS_IS_OK(status)) {
 398                         *dns_auth_error = DNS_RCODE_BADKEY;
 399                         return status;
 400                 }
 401                 *dns_auth_error = DNS_RCODE_OK;
 402         }
 403
 404         return status;
 405 }
 406
 407 static WERROR handle_tkey(struct dns_server *dns,
 408                           TALLOC_CTX *mem_ctx,
 409                           const struct dns_name_packet *in,
 410                           struct dns_res_rec **answers,
 411                           uint16_t *ancount)
 412 {
 413         struct dns_res_rec *in_tkey = NULL;
 414         struct dns_res_rec *ret_tkey;
 415         uint16_t i;
 416
 417         for (i = 0; i < in->arcount; i++) {
 418                 if (in->additional[i].rr_type == DNS_QTYPE_TKEY) {
 419                         in_tkey = &in->additional[i];
 420                         break;
 421                 }
 422         }
 423
 424         /* If this is a TKEY query, it should have a TKEY RR.
 425          * Behaviour is not really specified in RFC 2930 or RFC 3645, but
 426          * FORMAT_ERROR seems to be what BIND uses .*/
 427         if (in_tkey == NULL) {
 428                 return DNS_ERR(FORMAT_ERROR);
 429         }
 430
 431         ret_tkey = talloc_zero(mem_ctx, struct dns_res_rec);
 432         if (ret_tkey == NULL) {
 433                 return WERR_NOMEM;
 434         }
 435
 436         ret_tkey->name = talloc_strdup(ret_tkey, in_tkey->name);
 437         if (ret_tkey->name == NULL) {
 438                 return WERR_NOMEM;
 439         }
 440
 441         ret_tkey->rr_type = DNS_QTYPE_TKEY;
 442         ret_tkey->rr_class = DNS_QCLASS_ANY;
 443         ret_tkey->length = UINT16_MAX;
 444
 445         ret_tkey->rdata.tkey_record.algorithm = talloc_strdup(ret_tkey, ret_tkey->name);
 446         if (ret_tkey->rdata.tkey_record.algorithm  == NULL) {
 447                 return WERR_NOMEM;
 448         }
 449
 450         ret_tkey->rdata.tkey_record.inception = in_tkey->rdata.tkey_record.inception;
 451         ret_tkey->rdata.tkey_record.expiration = in_tkey->rdata.tkey_record.expiration;
 452         ret_tkey->rdata.tkey_record.mode = in_tkey->rdata.tkey_record.mode;
 453
 454         switch (in_tkey->rdata.tkey_record.mode) {
 455         case DNS_TKEY_MODE_DH:
 456                 /* FIXME: According to RFC 2930, we MUST support this, but we don't.
 457                  * Still, claim it's a bad key instead of a bad mode */
 458                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 459                 break;
 460         case DNS_TKEY_MODE_GSSAPI: {
 461                 NTSTATUS status;
 462                 struct dns_server_tkey *tkey;
 463                 DATA_BLOB key;
 464                 DATA_BLOB reply;
 465
 466                 tkey = dns_find_tkey(dns->tkeys, in->questions[0].name);
 467                 if (tkey != NULL && tkey->complete) {
 468                         /* TODO: check if the key is still valid */
 469                         DEBUG(1, ("Rejecting tkey negotiation for already established key\n"));
 470                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADNAME;
 471                         break;
 472                 }
 473
 474                 if (tkey == NULL) {
 475                         status  = create_tkey(dns, in->questions[0].name,
 476                                               &tkey);
 477                         if (!NT_STATUS_IS_OK(status)) {
 478                                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 479                                 return ntstatus_to_werror(status);
 480                         }
 481                 }
 482
 483                 key.data = in_tkey->rdata.tkey_record.key_data;
 484                 key.length = in_tkey->rdata.tkey_record.key_size;
 485
 486                 status = accept_gss_ticket(ret_tkey, dns, tkey, &key, &reply,
 487                                            &ret_tkey->rdata.tkey_record.error);
 488                 if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 489                         DEBUG(1, ("More processing required\n"));
 490                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 491                 } else if (NT_STATUS_IS_OK(status)) {
 492                         DEBUG(1, ("Tkey handshake completed\n"));
 493                 } else {
 494                         DEBUG(0, ("GSS key negotiation returned %s\n", nt_errstr(status)));
 495                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 496                 }
 497
 498                 break;
 499                 }
 500         case DNS_TKEY_MODE_DELETE:
 501                 /* TODO: implement me */
 502                 DEBUG(1, ("Should delete tkey here\n"));
 503                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_OK;
 504                 break;
 505         case DNS_TKEY_MODE_NULL:
 506         case DNS_TKEY_MODE_SERVER:
 507         case DNS_TKEY_MODE_CLIENT:
 508         case DNS_TKEY_MODE_LAST:
 509                 /* We don't have to implement these, return a mode error */
 510                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADMODE;
 511                 break;
 512         default:
 513                 DEBUG(1, ("Unsupported TKEY mode %d\n",
 514                       in_tkey->rdata.tkey_record.mode));
 515         }
 516
 517         *answers = ret_tkey;
 518         *ancount = 1;
 519
 520         return WERR_OK;
 521 }
 522
 523 struct dns_server_process_query_state {
 524         struct dns_res_rec *answers;
 525         uint16_t ancount;
 526         struct dns_res_rec *nsrecs;
 527         uint16_t nscount;
 528         struct dns_res_rec *additional;
 529         uint16_t arcount;
 530 };
 531
 532 static void dns_server_process_query_got_response(struct tevent_req *subreq);
 533
 534 struct tevent_req *dns_server_process_query_send(
 535         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 536         struct dns_server *dns, struct dns_request_state *req_state,
 537         const struct dns_name_packet *in)
 538 {
 539         struct tevent_req *req, *subreq;
 540         struct dns_server_process_query_state *state;
 541
 542         req = tevent_req_create(mem_ctx, &state,
 543                                 struct dns_server_process_query_state);
 544         if (req == NULL) {
 545                 return NULL;
 546         }
 547         if (in->qdcount != 1) {
 548                 tevent_req_werror(req, DNS_ERR(FORMAT_ERROR));
 549                 return tevent_req_post(req, ev);
 550         }
 551
 552         /* Windows returns NOT_IMPLEMENTED on this as well */
 553         if (in->questions[0].question_class == DNS_QCLASS_NONE) {
 554                 tevent_req_werror(req, DNS_ERR(NOT_IMPLEMENTED));
 555                 return tevent_req_post(req, ev);
 556         }
 557
 558         if (in->questions[0].question_type == DNS_QTYPE_TKEY) {
 559                 WERROR err;
 560
 561                 err = handle_tkey(dns, state, in, &state->answers,
 562                                   &state->ancount);
 563                 if (tevent_req_werror(req, err)) {
 564                         return tevent_req_post(req, ev);
 565                 }
 566                 tevent_req_done(req);
 567                 return tevent_req_post(req, ev);
 568         }
 569
 570         if (dns_authorative_for_zone(dns, in->questions[0].name)) {
 571                 WERROR err;
 572
 573                 req_state->flags |= DNS_FLAG_AUTHORITATIVE;
 574                 err = handle_question(dns, state, &in->questions[0],
 575                                       &state->answers, &state->ancount);
 576                 if (tevent_req_werror(req, err)) {
 577                         return tevent_req_post(req, ev);
 578                 }
 579                 tevent_req_done(req);
 580                 return tevent_req_post(req, ev);
 581         }
 582
 583         if ((req_state->flags & DNS_FLAG_RECURSION_DESIRED) &&
 584             (req_state->flags & DNS_FLAG_RECURSION_AVAIL)) {
 585                 DEBUG(2, ("Not authoritative for '%s', forwarding\n",
 586                           in->questions[0].name));
 587
 588                 subreq = ask_forwarder_send(
 589                         state, ev, lpcfg_dns_forwarder(dns->task->lp_ctx),
 590                         &in->questions[0]);
 591                 if (tevent_req_nomem(subreq, req)) {
 592                         return tevent_req_post(req, ev);
 593                 }
 594                 tevent_req_set_callback(
 595                         subreq, dns_server_process_query_got_response, req);
 596                 return req;
 597         }
 598
 599         tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 600         return tevent_req_post(req, ev);
 601 }
 602
 603 static void dns_server_process_query_got_response(struct tevent_req *subreq)
 604 {
 605         struct tevent_req *req = tevent_req_callback_data(
 606                 subreq, struct tevent_req);
 607         struct dns_server_process_query_state *state = tevent_req_data(
 608                 req, struct dns_server_process_query_state);
 609         WERROR err;
 610
 611         err = ask_forwarder_recv(subreq, state,
 612                                  &state->answers, &state->ancount,
 613                                  &state->nsrecs, &state->nscount,
 614                                  &state->additional, &state->arcount);
 615         TALLOC_FREE(subreq);
 616         if (tevent_req_werror(req, err)) {
 617                 return;
 618         }
 619         tevent_req_done(req);
 620 }
 621
 622 WERROR dns_server_process_query_recv(
 623         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 624         struct dns_res_rec **answers,    uint16_t *ancount,
 625         struct dns_res_rec **nsrecs,     uint16_t *nscount,
 626         struct dns_res_rec **additional, uint16_t *arcount)
 627 {
 628         struct dns_server_process_query_state *state = tevent_req_data(
 629                 req, struct dns_server_process_query_state);
 630         WERROR err;
 631
 632         if (tevent_req_is_werror(req, &err)) {
 633                 return err;
 634         }
 635         *answers = talloc_move(mem_ctx, &state->answers);
 636         *ancount = state->ancount;
 637         *nsrecs = talloc_move(mem_ctx, &state->nsrecs);
 638         *nscount = state->nscount;
 639         *additional = talloc_move(mem_ctx, &state->additional);
 640         *arcount = state->arcount;
 641         return WERR_OK;
 642 }