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 accept_gss_ticket(TALLOC_CTX *mem_ctx,
 324                                   struct dns_server *dns,
 325                                   struct dns_server_tkey *tkey,
 326                                   const DATA_BLOB *key,
 327                                   DATA_BLOB *reply,
 328                                   uint16_t *dns_auth_error)
 329 {
 330         NTSTATUS status;
 331
 332         status = gensec_update(tkey->gensec, mem_ctx, dns->task->event_ctx,
 333                                *key, reply);
 334
 335         if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
 336                 *dns_auth_error = DNS_RCODE_OK;
 337                 return status;
 338         }
 339
 340         if (NT_STATUS_IS_OK(status)) {
 341
 342                 status = gensec_session_info(tkey->gensec, tkey, &tkey->session_info);
 343                 if (!NT_STATUS_IS_OK(status)) {
 344                         *dns_auth_error = DNS_RCODE_BADKEY;
 345                         return status;
 346                 }
 347                 *dns_auth_error = DNS_RCODE_OK;
 348         }
 349
 350         return status;
 351 }
 352
 353 static struct dns_server_tkey *find_tkey(struct dns_server_tkey_store *store,
 354                                          const char *name)
 355 {
 356         struct dns_server_tkey *tkey = NULL;
 357         uint16_t i = 0;
 358
 359         do {
 360                 struct dns_server_tkey *tmp_key = store->tkeys[i];
 361
 362                 i++;
 363                 i %= TKEY_BUFFER_SIZE;
 364
 365                 if (tmp_key == NULL) {
 366                         continue;
 367                 }
 368                 if (dns_name_equal(name, tmp_key->name)) {
 369                         tkey = tmp_key;
 370                         break;
 371                 }
 372         } while (i != 0);
 373
 374         return tkey;
 375 }
 376
 377 static NTSTATUS create_tkey(struct dns_server *dns,
 378                             const char* name,
 379                             struct dns_server_tkey **tkey)
 380 {
 381         NTSTATUS status;
 382         struct dns_server_tkey_store *store = dns->tkeys;
 383         struct dns_server_tkey *k = talloc_zero(store, struct dns_server_tkey);
 384
 385         if (k == NULL) {
 386                 return NT_STATUS_NO_MEMORY;
 387         }
 388
 389         k->name = talloc_strdup(k, name);
 390
 391         if (k->name  == NULL) {
 392                 return NT_STATUS_NO_MEMORY;
 393         }
 394
 395         status = samba_server_gensec_start(k,
 396                                            dns->task->event_ctx,
 397                                            dns->task->msg_ctx,
 398                                            dns->task->lp_ctx,
 399                                            dns->server_credentials,
 400                                            "dns",
 401                                            &k->gensec);
 402         if (!NT_STATUS_IS_OK(status)) {
 403                 DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
 404                 *tkey = NULL;
 405                 return status;
 406         }
 407
 408         gensec_want_feature(k->gensec, GENSEC_FEATURE_SIGN);
 409
 410         status = gensec_start_mech_by_oid(k->gensec, GENSEC_OID_SPNEGO);
 411
 412         if (!NT_STATUS_IS_OK(status)) {
 413                 DEBUG(1, ("Failed to start GENSEC server code: %s\n",
 414                           nt_errstr(status)));
 415                 *tkey = NULL;
 416                 return status;
 417         }
 418
 419         if (store->tkeys[store->next_idx] != NULL) {
 420                 TALLOC_FREE(store->tkeys[store->next_idx]);
 421         }
 422
 423         store->tkeys[store->next_idx] = k;
 424         (store->next_idx)++;
 425         store->next_idx %= store->size;
 426
 427         *tkey = k;
 428         return NT_STATUS_OK;
 429 }
 430
 431 static WERROR handle_tkey(struct dns_server *dns,
 432                           TALLOC_CTX *mem_ctx,
 433                           const struct dns_name_packet *in,
 434                           struct dns_res_rec **answers,
 435                           uint16_t *ancount)
 436 {
 437         struct dns_res_rec *in_tkey = NULL;
 438         struct dns_res_rec *ret_tkey;
 439         uint16_t i;
 440
 441         for (i = 0; i < in->arcount; i++) {
 442                 if (in->additional[i].rr_type == DNS_QTYPE_TKEY) {
 443                         in_tkey = &in->additional[i];
 444                         break;
 445                 }
 446         }
 447
 448         /* If this is a TKEY query, it should have a TKEY RR.
 449          * Behaviour is not really specified in RFC 2930 or RFC 3645, but
 450          * FORMAT_ERROR seems to be what BIND uses .*/
 451         if (in_tkey == NULL) {
 452                 return DNS_ERR(FORMAT_ERROR);
 453         }
 454
 455         ret_tkey = talloc_zero(mem_ctx, struct dns_res_rec);
 456         if (ret_tkey == NULL) {
 457                 return WERR_NOMEM;
 458         }
 459
 460         ret_tkey->name = talloc_strdup(ret_tkey, in_tkey->name);
 461         if (ret_tkey->name == NULL) {
 462                 return WERR_NOMEM;
 463         }
 464
 465         ret_tkey->rr_type = DNS_QTYPE_TKEY;
 466         ret_tkey->rr_class = DNS_QCLASS_ANY;
 467         ret_tkey->length = UINT16_MAX;
 468
 469         ret_tkey->rdata.tkey_record.algorithm = talloc_strdup(ret_tkey, ret_tkey->name);
 470         if (ret_tkey->rdata.tkey_record.algorithm  == NULL) {
 471                 return WERR_NOMEM;
 472         }
 473
 474         ret_tkey->rdata.tkey_record.inception = in_tkey->rdata.tkey_record.inception;
 475         ret_tkey->rdata.tkey_record.expiration = in_tkey->rdata.tkey_record.expiration;
 476         ret_tkey->rdata.tkey_record.mode = in_tkey->rdata.tkey_record.mode;
 477
 478         switch (in_tkey->rdata.tkey_record.mode) {
 479         case DNS_TKEY_MODE_DH:
 480                 /* FIXME: According to RFC 2930, we MUST support this, but we don't.
 481                  * Still, claim it's a bad key instead of a bad mode */
 482                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 483                 break;
 484         case DNS_TKEY_MODE_GSSAPI: {
 485                 NTSTATUS status;
 486                 struct dns_server_tkey *tkey;
 487                 DATA_BLOB key;
 488                 DATA_BLOB reply;
 489
 490                 tkey = find_tkey(dns->tkeys, in->questions[0].name);
 491                 if (tkey != NULL && tkey->complete) {
 492                         /* TODO: check if the key is still valid */
 493                         DEBUG(1, ("Rejecting tkey negotiation for already established key\n"));
 494                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADNAME;
 495                         break;
 496                 }
 497
 498                 if (tkey == NULL) {
 499                         status  = create_tkey(dns, in->questions[0].name,
 500                                               &tkey);
 501                         if (!NT_STATUS_IS_OK(status)) {
 502                                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 503                                 return ntstatus_to_werror(status);
 504                         }
 505                 }
 506
 507                 key.data = in_tkey->rdata.tkey_record.key_data;
 508                 key.length = in_tkey->rdata.tkey_record.key_size;
 509
 510                 status = accept_gss_ticket(ret_tkey, dns, tkey, &key, &reply,
 511                                            &ret_tkey->rdata.tkey_record.error);
 512                 if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 513                         DEBUG(1, ("More processing required\n"));
 514                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 515                 } else if (NT_STATUS_IS_OK(status)) {
 516                         DEBUG(1, ("Tkey handshake completed\n"));
 517                 } else {
 518                         DEBUG(0, ("GSS key negotiation returned %s\n", nt_errstr(status)));
 519                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 520                 }
 521
 522                 break;
 523                 }
 524         case DNS_TKEY_MODE_DELETE:
 525                 /* TODO: implement me */
 526                 DEBUG(1, ("Should delete tkey here\n"));
 527                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_OK;
 528                 break;
 529         case DNS_TKEY_MODE_NULL:
 530         case DNS_TKEY_MODE_SERVER:
 531         case DNS_TKEY_MODE_CLIENT:
 532         case DNS_TKEY_MODE_LAST:
 533                 /* We don't have to implement these, return a mode error */
 534                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADMODE;
 535                 break;
 536         default:
 537                 DEBUG(1, ("Unsupported TKEY mode %d\n",
 538                       in_tkey->rdata.tkey_record.mode));
 539         }
 540
 541         *answers = ret_tkey;
 542         *ancount = 1;
 543
 544         return WERR_OK;
 545 }
 546
 547 struct dns_server_process_query_state {
 548         struct dns_res_rec *answers;
 549         uint16_t ancount;
 550         struct dns_res_rec *nsrecs;
 551         uint16_t nscount;
 552         struct dns_res_rec *additional;
 553         uint16_t arcount;
 554 };
 555
 556 static void dns_server_process_query_got_response(struct tevent_req *subreq);
 557
 558 struct tevent_req *dns_server_process_query_send(
 559         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 560         struct dns_server *dns, struct dns_request_state *req_state,
 561         const struct dns_name_packet *in)
 562 {
 563         struct tevent_req *req, *subreq;
 564         struct dns_server_process_query_state *state;
 565
 566         req = tevent_req_create(mem_ctx, &state,
 567                                 struct dns_server_process_query_state);
 568         if (req == NULL) {
 569                 return NULL;
 570         }
 571         if (in->qdcount != 1) {
 572                 tevent_req_werror(req, DNS_ERR(FORMAT_ERROR));
 573                 return tevent_req_post(req, ev);
 574         }
 575
 576         /* Windows returns NOT_IMPLEMENTED on this as well */
 577         if (in->questions[0].question_class == DNS_QCLASS_NONE) {
 578                 tevent_req_werror(req, DNS_ERR(NOT_IMPLEMENTED));
 579                 return tevent_req_post(req, ev);
 580         }
 581
 582         if (in->questions[0].question_type == DNS_QTYPE_TKEY) {
 583                 WERROR err;
 584
 585                 err = handle_tkey(dns, state, in, &state->answers,
 586                                   &state->ancount);
 587                 if (tevent_req_werror(req, err)) {
 588                         return tevent_req_post(req, ev);
 589                 }
 590                 tevent_req_done(req);
 591                 return tevent_req_post(req, ev);
 592         }
 593
 594         if (dns_authorative_for_zone(dns, in->questions[0].name)) {
 595                 WERROR err;
 596
 597                 req_state->flags |= DNS_FLAG_AUTHORITATIVE;
 598                 err = handle_question(dns, state, &in->questions[0],
 599                                       &state->answers, &state->ancount);
 600                 if (tevent_req_werror(req, err)) {
 601                         return tevent_req_post(req, ev);
 602                 }
 603                 tevent_req_done(req);
 604                 return tevent_req_post(req, ev);
 605         }
 606
 607         if ((req_state->flags & DNS_FLAG_RECURSION_DESIRED) &&
 608             (req_state->flags & DNS_FLAG_RECURSION_AVAIL)) {
 609                 DEBUG(2, ("Not authoritative for '%s', forwarding\n",
 610                           in->questions[0].name));
 611
 612                 subreq = ask_forwarder_send(
 613                         state, ev, lpcfg_dns_forwarder(dns->task->lp_ctx),
 614                         &in->questions[0]);
 615                 if (tevent_req_nomem(subreq, req)) {
 616                         return tevent_req_post(req, ev);
 617                 }
 618                 tevent_req_set_callback(
 619                         subreq, dns_server_process_query_got_response, req);
 620                 return req;
 621         }
 622
 623         tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 624         return tevent_req_post(req, ev);
 625 }
 626
 627 static void dns_server_process_query_got_response(struct tevent_req *subreq)
 628 {
 629         struct tevent_req *req = tevent_req_callback_data(
 630                 subreq, struct tevent_req);
 631         struct dns_server_process_query_state *state = tevent_req_data(
 632                 req, struct dns_server_process_query_state);
 633         WERROR err;
 634
 635         err = ask_forwarder_recv(subreq, state,
 636                                  &state->answers, &state->ancount,
 637                                  &state->nsrecs, &state->nscount,
 638                                  &state->additional, &state->arcount);
 639         TALLOC_FREE(subreq);
 640         if (tevent_req_werror(req, err)) {
 641                 return;
 642         }
 643         tevent_req_done(req);
 644 }
 645
 646 WERROR dns_server_process_query_recv(
 647         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 648         struct dns_res_rec **answers,    uint16_t *ancount,
 649         struct dns_res_rec **nsrecs,     uint16_t *nscount,
 650         struct dns_res_rec **additional, uint16_t *arcount)
 651 {
 652         struct dns_server_process_query_state *state = tevent_req_data(
 653                 req, struct dns_server_process_query_state);
 654         WERROR err;
 655
 656         if (tevent_req_is_werror(req, &err)) {
 657                 return err;
 658         }
 659         *answers = talloc_move(mem_ctx, &state->answers);
 660         *ancount = state->ancount;
 661         *nsrecs = talloc_move(mem_ctx, &state->nsrecs);
 662         *nscount = state->nscount;
 663         *additional = talloc_move(mem_ctx, &state->additional);
 664         *arcount = state->arcount;
 665         return WERR_OK;
 666 }