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_MX:
  93                 ans[ai].rdata.mx_record.preference = rec->data.mx.wPriority;
  94                 ans[ai].rdata.mx_record.exchange = talloc_strdup(
  95                         ans, rec->data.mx.nameTarget);
  96                 if (ans[ai].rdata.mx_record.exchange == NULL) {
  97                         return WERR_NOMEM;
  98                 }
  99                 break;
 100         case DNS_QTYPE_TXT:
 101                 tmp = talloc_asprintf(ans, "\"%s\"", rec->data.txt.str[0]);
 102                 W_ERROR_HAVE_NO_MEMORY(tmp);
 103                 for (i=1; i<rec->data.txt.count; i++) {
 104                         tmp = talloc_asprintf_append_buffer(
 105                                 tmp, " \"%s\"", rec->data.txt.str[i]);
 106                         W_ERROR_HAVE_NO_MEMORY(tmp);
 107                 }
 108                 ans[ai].rdata.txt_record.txt = tmp;
 109                 break;
 110         default:
 111                 DEBUG(0, ("Got unhandled type %u query.\n", rec->wType));
 112                 return DNS_ERR(NOT_IMPLEMENTED);
 113         }
 114
 115         ans[ai].name = talloc_strdup(ans, question->name);
 116         W_ERROR_HAVE_NO_MEMORY(ans[ai].name);
 117         ans[ai].rr_type = rec->wType;
 118         ans[ai].rr_class = DNS_QCLASS_IN;
 119         ans[ai].ttl = rec->dwTtlSeconds;
 120         ans[ai].length = UINT16_MAX;
 121         ai++;
 122
 123         *answers = ans;
 124         *ancount = ai;
 125
 126         return WERR_OK;
 127 }
 128
 129 struct ask_forwarder_state {
 130         struct tevent_context *ev;
 131         uint16_t id;
 132         struct dns_name_packet in_packet;
 133 };
 134
 135 static void ask_forwarder_done(struct tevent_req *subreq);
 136
 137 static struct tevent_req *ask_forwarder_send(
 138         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 139         const char *forwarder, struct dns_name_question *question)
 140 {
 141         struct tevent_req *req, *subreq;
 142         struct ask_forwarder_state *state;
 143         struct dns_name_packet out_packet = { 0, };
 144         DATA_BLOB out_blob;
 145         enum ndr_err_code ndr_err;
 146
 147         req = tevent_req_create(mem_ctx, &state, struct ask_forwarder_state);
 148         if (req == NULL) {
 149                 return NULL;
 150         }
 151         state->ev = ev;
 152         generate_random_buffer((uint8_t *)&state->id, sizeof(state->id));
 153
 154         if (!is_ipaddress(forwarder)) {
 155                 DEBUG(0, ("Invalid 'dns forwarder' setting '%s', needs to be "
 156                           "an IP address\n", forwarder));
 157                 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 158                 return tevent_req_post(req, ev);
 159         }
 160
 161         out_packet.id = state->id;
 162         out_packet.operation |= DNS_OPCODE_QUERY | DNS_FLAG_RECURSION_DESIRED;
 163         out_packet.qdcount = 1;
 164         out_packet.questions = question;
 165
 166         ndr_err = ndr_push_struct_blob(
 167                 &out_blob, state, &out_packet,
 168                 (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 169         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 170                 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
 171                 return tevent_req_post(req, ev);
 172         }
 173         subreq = dns_udp_request_send(state, ev, forwarder, out_blob.data,
 174                                       out_blob.length);
 175         if (tevent_req_nomem(subreq, req)) {
 176                 return tevent_req_post(req, ev);
 177         }
 178         tevent_req_set_callback(subreq, ask_forwarder_done, req);
 179         return req;
 180 }
 181
 182 static void ask_forwarder_done(struct tevent_req *subreq)
 183 {
 184         struct tevent_req *req = tevent_req_callback_data(
 185                 subreq, struct tevent_req);
 186         struct ask_forwarder_state *state = tevent_req_data(
 187                 req, struct ask_forwarder_state);
 188         DATA_BLOB in_blob;
 189         enum ndr_err_code ndr_err;
 190         WERROR ret;
 191
 192         ret = dns_udp_request_recv(subreq, state,
 193                                    &in_blob.data, &in_blob.length);
 194         TALLOC_FREE(subreq);
 195         if (tevent_req_werror(req, ret)) {
 196                 return;
 197         }
 198
 199         ndr_err = ndr_pull_struct_blob(
 200                 &in_blob, state, &state->in_packet,
 201                 (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 202         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 203                 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
 204                 return;
 205         }
 206         if (state->in_packet.id != state->id) {
 207                 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 208                 return;
 209         }
 210         tevent_req_done(req);
 211 }
 212
 213 static WERROR ask_forwarder_recv(
 214         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 215         struct dns_res_rec **answers, uint16_t *ancount,
 216         struct dns_res_rec **nsrecs, uint16_t *nscount,
 217         struct dns_res_rec **additional, uint16_t *arcount)
 218 {
 219         struct ask_forwarder_state *state = tevent_req_data(
 220                 req, struct ask_forwarder_state);
 221         struct dns_name_packet *in_packet = &state->in_packet;
 222         WERROR err;
 223
 224         if (tevent_req_is_werror(req, &err)) {
 225                 return err;
 226         }
 227
 228         *ancount = in_packet->ancount;
 229         *answers = talloc_move(mem_ctx, &in_packet->answers);
 230
 231         *nscount = in_packet->nscount;
 232         *nsrecs = talloc_move(mem_ctx, &in_packet->nsrecs);
 233
 234         *arcount = in_packet->arcount;
 235         *additional = talloc_move(mem_ctx, &in_packet->additional);
 236
 237         return WERR_OK;
 238 }
 239
 240 static WERROR handle_question(struct dns_server *dns,
 241                               TALLOC_CTX *mem_ctx,
 242                               const struct dns_name_question *question,
 243                               struct dns_res_rec **answers, uint16_t *ancount)
 244 {
 245         struct dns_res_rec *ans = *answers;
 246         WERROR werror;
 247         unsigned int ri;
 248         struct dnsp_DnssrvRpcRecord *recs;
 249         uint16_t rec_count, ai = *ancount;
 250         struct ldb_dn *dn = NULL;
 251
 252         werror = dns_name2dn(dns, mem_ctx, question->name, &dn);
 253         W_ERROR_NOT_OK_RETURN(werror);
 254
 255         werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rec_count);
 256         W_ERROR_NOT_OK_RETURN(werror);
 257
 258         ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec, rec_count + ai);
 259         if (ans == NULL) {
 260                 return WERR_NOMEM;
 261         }
 262
 263         for (ri = 0; ri < rec_count; ri++) {
 264                 if ((recs[ri].wType == DNS_TYPE_CNAME) &&
 265                     ((question->question_type == DNS_QTYPE_A) ||
 266                      (question->question_type == DNS_QTYPE_AAAA))) {
 267                         struct dns_name_question *new_q =
 268                                 talloc(mem_ctx, struct dns_name_question);
 269
 270                         if (new_q == NULL) {
 271                                 return WERR_NOMEM;
 272                         }
 273
 274                         /* We reply with one more record, so grow the array */
 275                         ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec,
 276                                              rec_count + 1);
 277                         if (ans == NULL) {
 278                                 TALLOC_FREE(new_q);
 279                                 return WERR_NOMEM;
 280                         }
 281
 282                         /* First put in the CNAME record */
 283                         werror = create_response_rr(question, &recs[ri], &ans, &ai);
 284                         if (!W_ERROR_IS_OK(werror)) {
 285                                 return werror;
 286                         }
 287
 288                         /* And then look up the name it points at.. */
 289
 290                         /* First build up the new question */
 291                         new_q->question_type = question->question_type;
 292                         new_q->question_class = question->question_class;
 293                         if (new_q->question_type == DNS_QTYPE_A) {
 294                                 new_q->name = talloc_strdup(new_q, recs[ri].data.ipv4);
 295                         } else if (new_q->question_type == DNS_QTYPE_AAAA) {
 296                                 new_q->name = talloc_strdup(new_q, recs[ri].data.ipv6);
 297                         }
 298                         if (new_q->name == NULL) {
 299                                 TALLOC_FREE(new_q);
 300                                 return WERR_NOMEM;
 301                         }
 302                         /* and then call the lookup again */
 303                         werror = handle_question(dns, mem_ctx, new_q, &ans, &ai);
 304                         if (!W_ERROR_IS_OK(werror)) {
 305                                 return werror;
 306                         }
 307
 308
 309                         continue;
 310                 }
 311                 if ((question->question_type != DNS_QTYPE_ALL) &&
 312                     (recs[ri].wType != question->question_type)) {
 313                         continue;
 314                 }
 315                 werror = create_response_rr(question, &recs[ri], &ans, &ai);
 316                 if (!W_ERROR_IS_OK(werror)) {
 317                         return werror;
 318                 }
 319         }
 320
 321         if (ai == 0) {
 322                 return DNS_ERR(NAME_ERROR);
 323         }
 324
 325         *ancount = ai;
 326         *answers = ans;
 327
 328         return WERR_OK;
 329 }
 330
 331 static NTSTATUS create_tkey(struct dns_server *dns,
 332                             const char* name,
 333                             const char* algorithm,
 334                             struct dns_server_tkey **tkey)
 335 {
 336         NTSTATUS status;
 337         struct dns_server_tkey_store *store = dns->tkeys;
 338         struct dns_server_tkey *k = talloc_zero(store, struct dns_server_tkey);
 339
 340         if (k == NULL) {
 341                 return NT_STATUS_NO_MEMORY;
 342         }
 343
 344         k->name = talloc_strdup(k, name);
 345
 346         if (k->name  == NULL) {
 347                 return NT_STATUS_NO_MEMORY;
 348         }
 349
 350         k->algorithm = talloc_strdup(k, algorithm);
 351         if (k->algorithm == NULL) {
 352                 return NT_STATUS_NO_MEMORY;
 353         }
 354
 355         status = samba_server_gensec_start(k,
 356                                            dns->task->event_ctx,
 357                                            dns->task->msg_ctx,
 358                                            dns->task->lp_ctx,
 359                                            dns->server_credentials,
 360                                            "dns",
 361                                            &k->gensec);
 362         if (!NT_STATUS_IS_OK(status)) {
 363                 DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
 364                 *tkey = NULL;
 365                 return status;
 366         }
 367
 368         gensec_want_feature(k->gensec, GENSEC_FEATURE_SIGN);
 369
 370         status = gensec_start_mech_by_oid(k->gensec, GENSEC_OID_SPNEGO);
 371
 372         if (!NT_STATUS_IS_OK(status)) {
 373                 DEBUG(1, ("Failed to start GENSEC server code: %s\n",
 374                           nt_errstr(status)));
 375                 *tkey = NULL;
 376                 return status;
 377         }
 378
 379         if (store->tkeys[store->next_idx] != NULL) {
 380                 TALLOC_FREE(store->tkeys[store->next_idx]);
 381         }
 382
 383         store->tkeys[store->next_idx] = k;
 384         (store->next_idx)++;
 385         store->next_idx %= store->size;
 386
 387         *tkey = k;
 388         return NT_STATUS_OK;
 389 }
 390
 391 static NTSTATUS accept_gss_ticket(TALLOC_CTX *mem_ctx,
 392                                   struct dns_server *dns,
 393                                   struct dns_server_tkey *tkey,
 394                                   const DATA_BLOB *key,
 395                                   DATA_BLOB *reply,
 396                                   uint16_t *dns_auth_error)
 397 {
 398         NTSTATUS status;
 399
 400         status = gensec_update(tkey->gensec, mem_ctx, dns->task->event_ctx,
 401                                *key, reply);
 402
 403         if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
 404                 *dns_auth_error = DNS_RCODE_OK;
 405                 return status;
 406         }
 407
 408         if (NT_STATUS_IS_OK(status)) {
 409
 410                 status = gensec_session_info(tkey->gensec, tkey, &tkey->session_info);
 411                 if (!NT_STATUS_IS_OK(status)) {
 412                         *dns_auth_error = DNS_RCODE_BADKEY;
 413                         return status;
 414                 }
 415                 *dns_auth_error = DNS_RCODE_OK;
 416         }
 417
 418         return status;
 419 }
 420
 421 static WERROR handle_tkey(struct dns_server *dns,
 422                           TALLOC_CTX *mem_ctx,
 423                           const struct dns_name_packet *in,
 424                           struct dns_request_state *state,
 425                           struct dns_res_rec **answers,
 426                           uint16_t *ancount)
 427 {
 428         struct dns_res_rec *in_tkey = NULL;
 429         struct dns_res_rec *ret_tkey;
 430         uint16_t i;
 431
 432         for (i = 0; i < in->arcount; i++) {
 433                 if (in->additional[i].rr_type == DNS_QTYPE_TKEY) {
 434                         in_tkey = &in->additional[i];
 435                         break;
 436                 }
 437         }
 438
 439         /* If this is a TKEY query, it should have a TKEY RR.
 440          * Behaviour is not really specified in RFC 2930 or RFC 3645, but
 441          * FORMAT_ERROR seems to be what BIND uses .*/
 442         if (in_tkey == NULL) {
 443                 return DNS_ERR(FORMAT_ERROR);
 444         }
 445
 446         ret_tkey = talloc_zero(mem_ctx, struct dns_res_rec);
 447         if (ret_tkey == NULL) {
 448                 return WERR_NOMEM;
 449         }
 450
 451         ret_tkey->name = talloc_strdup(ret_tkey, in_tkey->name);
 452         if (ret_tkey->name == NULL) {
 453                 return WERR_NOMEM;
 454         }
 455
 456         ret_tkey->rr_type = DNS_QTYPE_TKEY;
 457         ret_tkey->rr_class = DNS_QCLASS_ANY;
 458         ret_tkey->length = UINT16_MAX;
 459
 460         ret_tkey->rdata.tkey_record.algorithm = talloc_strdup(ret_tkey,
 461                         in_tkey->rdata.tkey_record.algorithm);
 462         if (ret_tkey->rdata.tkey_record.algorithm  == NULL) {
 463                 return WERR_NOMEM;
 464         }
 465
 466         ret_tkey->rdata.tkey_record.inception = in_tkey->rdata.tkey_record.inception;
 467         ret_tkey->rdata.tkey_record.expiration = in_tkey->rdata.tkey_record.expiration;
 468         ret_tkey->rdata.tkey_record.mode = in_tkey->rdata.tkey_record.mode;
 469
 470         switch (in_tkey->rdata.tkey_record.mode) {
 471         case DNS_TKEY_MODE_DH:
 472                 /* FIXME: According to RFC 2930, we MUST support this, but we don't.
 473                  * Still, claim it's a bad key instead of a bad mode */
 474                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 475                 break;
 476         case DNS_TKEY_MODE_GSSAPI: {
 477                 NTSTATUS status;
 478                 struct dns_server_tkey *tkey;
 479                 DATA_BLOB key;
 480                 DATA_BLOB reply;
 481
 482                 tkey = dns_find_tkey(dns->tkeys, in->questions[0].name);
 483                 if (tkey != NULL && tkey->complete) {
 484                         /* TODO: check if the key is still valid */
 485                         DEBUG(1, ("Rejecting tkey negotiation for already established key\n"));
 486                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADNAME;
 487                         break;
 488                 }
 489
 490                 if (tkey == NULL) {
 491                         status  = create_tkey(dns, in->questions[0].name,
 492                                               in_tkey->rdata.tkey_record.algorithm,
 493                                               &tkey);
 494                         if (!NT_STATUS_IS_OK(status)) {
 495                                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 496                                 return ntstatus_to_werror(status);
 497                         }
 498                 }
 499
 500                 key.data = in_tkey->rdata.tkey_record.key_data;
 501                 key.length = in_tkey->rdata.tkey_record.key_size;
 502
 503                 status = accept_gss_ticket(ret_tkey, dns, tkey, &key, &reply,
 504                                            &ret_tkey->rdata.tkey_record.error);
 505                 if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 506                         DEBUG(1, ("More processing required\n"));
 507                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 508                 } else if (NT_STATUS_IS_OK(status)) {
 509                         DEBUG(1, ("Tkey handshake completed\n"));
 510                         ret_tkey->rdata.tkey_record.key_size = reply.length;
 511                         ret_tkey->rdata.tkey_record.key_data = talloc_memdup(ret_tkey,
 512                                                                 reply.data,
 513                                                                 reply.length);
 514                         state->sign = true;
 515                         state->key_name = talloc_strdup(mem_ctx, tkey->name);
 516                         if (state->key_name == NULL) {
 517                                 return WERR_NOMEM;
 518                         }
 519                 } else {
 520                         DEBUG(1, ("GSS key negotiation returned %s\n", nt_errstr(status)));
 521                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 522                 }
 523
 524                 break;
 525                 }
 526         case DNS_TKEY_MODE_DELETE:
 527                 /* TODO: implement me */
 528                 DEBUG(1, ("Should delete tkey here\n"));
 529                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_OK;
 530                 break;
 531         case DNS_TKEY_MODE_NULL:
 532         case DNS_TKEY_MODE_SERVER:
 533         case DNS_TKEY_MODE_CLIENT:
 534         case DNS_TKEY_MODE_LAST:
 535                 /* We don't have to implement these, return a mode error */
 536                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADMODE;
 537                 break;
 538         default:
 539                 DEBUG(1, ("Unsupported TKEY mode %d\n",
 540                       in_tkey->rdata.tkey_record.mode));
 541         }
 542
 543         *answers = ret_tkey;
 544         *ancount = 1;
 545
 546         return WERR_OK;
 547 }
 548
 549 struct dns_server_process_query_state {
 550         struct dns_res_rec *answers;
 551         uint16_t ancount;
 552         struct dns_res_rec *nsrecs;
 553         uint16_t nscount;
 554         struct dns_res_rec *additional;
 555         uint16_t arcount;
 556 };
 557
 558 static void dns_server_process_query_got_response(struct tevent_req *subreq);
 559
 560 struct tevent_req *dns_server_process_query_send(
 561         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 562         struct dns_server *dns, struct dns_request_state *req_state,
 563         const struct dns_name_packet *in)
 564 {
 565         struct tevent_req *req, *subreq;
 566         struct dns_server_process_query_state *state;
 567
 568         req = tevent_req_create(mem_ctx, &state,
 569                                 struct dns_server_process_query_state);
 570         if (req == NULL) {
 571                 return NULL;
 572         }
 573         if (in->qdcount != 1) {
 574                 tevent_req_werror(req, DNS_ERR(FORMAT_ERROR));
 575                 return tevent_req_post(req, ev);
 576         }
 577
 578         /* Windows returns NOT_IMPLEMENTED on this as well */
 579         if (in->questions[0].question_class == DNS_QCLASS_NONE) {
 580                 tevent_req_werror(req, DNS_ERR(NOT_IMPLEMENTED));
 581                 return tevent_req_post(req, ev);
 582         }
 583
 584         if (in->questions[0].question_type == DNS_QTYPE_TKEY) {
 585                 WERROR err;
 586
 587                 err = handle_tkey(dns, state, in, req_state,
 588                                   &state->answers, &state->ancount);
 589                 if (tevent_req_werror(req, err)) {
 590                         return tevent_req_post(req, ev);
 591                 }
 592                 tevent_req_done(req);
 593                 return tevent_req_post(req, ev);
 594         }
 595
 596         if (dns_authorative_for_zone(dns, in->questions[0].name)) {
 597                 WERROR err;
 598
 599                 req_state->flags |= DNS_FLAG_AUTHORITATIVE;
 600                 err = handle_question(dns, state, &in->questions[0],
 601                                       &state->answers, &state->ancount);
 602                 if (tevent_req_werror(req, err)) {
 603                         return tevent_req_post(req, ev);
 604                 }
 605                 tevent_req_done(req);
 606                 return tevent_req_post(req, ev);
 607         }
 608
 609         if ((req_state->flags & DNS_FLAG_RECURSION_DESIRED) &&
 610             (req_state->flags & DNS_FLAG_RECURSION_AVAIL)) {
 611                 DEBUG(2, ("Not authoritative for '%s', forwarding\n",
 612                           in->questions[0].name));
 613
 614                 subreq = ask_forwarder_send(
 615                         state, ev, lpcfg_dns_forwarder(dns->task->lp_ctx),
 616                         &in->questions[0]);
 617                 if (tevent_req_nomem(subreq, req)) {
 618                         return tevent_req_post(req, ev);
 619                 }
 620                 tevent_req_set_callback(
 621                         subreq, dns_server_process_query_got_response, req);
 622                 return req;
 623         }
 624
 625         tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 626         return tevent_req_post(req, ev);
 627 }
 628
 629 static void dns_server_process_query_got_response(struct tevent_req *subreq)
 630 {
 631         struct tevent_req *req = tevent_req_callback_data(
 632                 subreq, struct tevent_req);
 633         struct dns_server_process_query_state *state = tevent_req_data(
 634                 req, struct dns_server_process_query_state);
 635         WERROR err;
 636
 637         err = ask_forwarder_recv(subreq, state,
 638                                  &state->answers, &state->ancount,
 639                                  &state->nsrecs, &state->nscount,
 640                                  &state->additional, &state->arcount);
 641         TALLOC_FREE(subreq);
 642         if (tevent_req_werror(req, err)) {
 643                 return;
 644         }
 645         tevent_req_done(req);
 646 }
 647
 648 WERROR dns_server_process_query_recv(
 649         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 650         struct dns_res_rec **answers,    uint16_t *ancount,
 651         struct dns_res_rec **nsrecs,     uint16_t *nscount,
 652         struct dns_res_rec **additional, uint16_t *arcount)
 653 {
 654         struct dns_server_process_query_state *state = tevent_req_data(
 655                 req, struct dns_server_process_query_state);
 656         WERROR err;
 657
 658         if (tevent_req_is_werror(req, &err)) {
 659                 return err;
 660         }
 661         *answers = talloc_move(mem_ctx, &state->answers);
 662         *ancount = state->ancount;
 663         *nsrecs = talloc_move(mem_ctx, &state->nsrecs);
 664         *nscount = state->nscount;
 665         *additional = talloc_move(mem_ctx, &state->additional);
 666         *arcount = state->arcount;
 667         return WERR_OK;
 668 }