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 #undef DBGC_CLASS
  41 #define DBGC_CLASS DBGC_DNS
  42
  43 static WERROR create_response_rr(const struct dns_name_question *question,
  44                                  const struct dnsp_DnssrvRpcRecord *rec,
  45                                  struct dns_res_rec **answers, uint16_t *ancount)
  46 {
  47         struct dns_res_rec *ans = *answers;
  48         uint16_t ai = *ancount;
  49         char *tmp;
  50         uint32_t i;
  51
  52         ZERO_STRUCT(ans[ai]);
  53
  54         switch (rec->wType) {
  55         case DNS_QTYPE_CNAME:
  56                 ans[ai].rdata.cname_record = talloc_strdup(ans, rec->data.cname);
  57                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.cname_record);
  58                 break;
  59         case DNS_QTYPE_A:
  60                 ans[ai].rdata.ipv4_record = talloc_strdup(ans, rec->data.ipv4);
  61                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ipv4_record);
  62                 break;
  63         case DNS_QTYPE_AAAA:
  64                 ans[ai].rdata.ipv6_record = talloc_strdup(ans, rec->data.ipv6);
  65                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ipv6_record);
  66                 break;
  67         case DNS_TYPE_NS:
  68                 ans[ai].rdata.ns_record = talloc_strdup(ans, rec->data.ns);
  69                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ns_record);
  70                 break;
  71         case DNS_QTYPE_SRV:
  72                 ans[ai].rdata.srv_record.priority = rec->data.srv.wPriority;
  73                 ans[ai].rdata.srv_record.weight   = rec->data.srv.wWeight;
  74                 ans[ai].rdata.srv_record.port     = rec->data.srv.wPort;
  75                 ans[ai].rdata.srv_record.target   = talloc_strdup(
  76                         ans, rec->data.srv.nameTarget);
  77                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.srv_record.target);
  78                 break;
  79         case DNS_QTYPE_SOA:
  80                 ans[ai].rdata.soa_record.mname   = talloc_strdup(
  81                         ans, rec->data.soa.mname);
  82                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.soa_record.mname);
  83                 ans[ai].rdata.soa_record.rname   = talloc_strdup(
  84                         ans, rec->data.soa.rname);
  85                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.soa_record.rname);
  86                 ans[ai].rdata.soa_record.serial  = rec->data.soa.serial;
  87                 ans[ai].rdata.soa_record.refresh = rec->data.soa.refresh;
  88                 ans[ai].rdata.soa_record.retry   = rec->data.soa.retry;
  89                 ans[ai].rdata.soa_record.expire  = rec->data.soa.expire;
  90                 ans[ai].rdata.soa_record.minimum = rec->data.soa.minimum;
  91                 break;
  92         case DNS_QTYPE_PTR:
  93                 ans[ai].rdata.ptr_record = talloc_strdup(ans, rec->data.ptr);
  94                 break;
  95         case DNS_QTYPE_MX:
  96                 ans[ai].rdata.mx_record.preference = rec->data.mx.wPriority;
  97                 ans[ai].rdata.mx_record.exchange = talloc_strdup(
  98                         ans, rec->data.mx.nameTarget);
  99                 if (ans[ai].rdata.mx_record.exchange == NULL) {
 100                         return WERR_NOMEM;
 101                 }
 102                 break;
 103         case DNS_QTYPE_TXT:
 104                 tmp = talloc_asprintf(ans, "\"%s\"", rec->data.txt.str[0]);
 105                 W_ERROR_HAVE_NO_MEMORY(tmp);
 106                 for (i=1; i<rec->data.txt.count; i++) {
 107                         tmp = talloc_asprintf_append_buffer(
 108                                 tmp, " \"%s\"", rec->data.txt.str[i]);
 109                         W_ERROR_HAVE_NO_MEMORY(tmp);
 110                 }
 111                 ans[ai].rdata.txt_record.txt = tmp;
 112                 break;
 113         default:
 114                 DEBUG(0, ("Got unhandled type %u query.\n", rec->wType));
 115                 return DNS_ERR(NOT_IMPLEMENTED);
 116         }
 117
 118         ans[ai].name = talloc_strdup(ans, question->name);
 119         W_ERROR_HAVE_NO_MEMORY(ans[ai].name);
 120         ans[ai].rr_type = rec->wType;
 121         ans[ai].rr_class = DNS_QCLASS_IN;
 122         ans[ai].ttl = rec->dwTtlSeconds;
 123         ans[ai].length = UINT16_MAX;
 124         ai++;
 125
 126         *answers = ans;
 127         *ancount = ai;
 128
 129         return WERR_OK;
 130 }
 131
 132 struct ask_forwarder_state {
 133         struct tevent_context *ev;
 134         uint16_t id;
 135         struct dns_name_packet in_packet;
 136 };
 137
 138 static void ask_forwarder_done(struct tevent_req *subreq);
 139
 140 static struct tevent_req *ask_forwarder_send(
 141         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 142         const char *forwarder, struct dns_name_question *question)
 143 {
 144         struct tevent_req *req, *subreq;
 145         struct ask_forwarder_state *state;
 146         struct dns_name_packet out_packet = { 0, };
 147         DATA_BLOB out_blob;
 148         enum ndr_err_code ndr_err;
 149
 150         req = tevent_req_create(mem_ctx, &state, struct ask_forwarder_state);
 151         if (req == NULL) {
 152                 return NULL;
 153         }
 154         state->ev = ev;
 155         generate_random_buffer((uint8_t *)&state->id, sizeof(state->id));
 156
 157         if (!is_ipaddress(forwarder)) {
 158                 DEBUG(0, ("Invalid 'dns forwarder' setting '%s', needs to be "
 159                           "an IP address\n", forwarder));
 160                 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 161                 return tevent_req_post(req, ev);
 162         }
 163
 164         out_packet.id = state->id;
 165         out_packet.operation |= DNS_OPCODE_QUERY | DNS_FLAG_RECURSION_DESIRED;
 166         out_packet.qdcount = 1;
 167         out_packet.questions = question;
 168
 169         ndr_err = ndr_push_struct_blob(
 170                 &out_blob, state, &out_packet,
 171                 (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 172         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 173                 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
 174                 return tevent_req_post(req, ev);
 175         }
 176         subreq = dns_udp_request_send(state, ev, forwarder, out_blob.data,
 177                                       out_blob.length);
 178         if (tevent_req_nomem(subreq, req)) {
 179                 return tevent_req_post(req, ev);
 180         }
 181         tevent_req_set_callback(subreq, ask_forwarder_done, req);
 182         return req;
 183 }
 184
 185 static void ask_forwarder_done(struct tevent_req *subreq)
 186 {
 187         struct tevent_req *req = tevent_req_callback_data(
 188                 subreq, struct tevent_req);
 189         struct ask_forwarder_state *state = tevent_req_data(
 190                 req, struct ask_forwarder_state);
 191         DATA_BLOB in_blob;
 192         enum ndr_err_code ndr_err;
 193         WERROR ret;
 194
 195         ret = dns_udp_request_recv(subreq, state,
 196                                    &in_blob.data, &in_blob.length);
 197         TALLOC_FREE(subreq);
 198         if (tevent_req_werror(req, ret)) {
 199                 return;
 200         }
 201
 202         ndr_err = ndr_pull_struct_blob(
 203                 &in_blob, state, &state->in_packet,
 204                 (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 205         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 206                 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
 207                 return;
 208         }
 209         if (state->in_packet.id != state->id) {
 210                 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 211                 return;
 212         }
 213         tevent_req_done(req);
 214 }
 215
 216 static WERROR ask_forwarder_recv(
 217         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 218         struct dns_res_rec **answers, uint16_t *ancount,
 219         struct dns_res_rec **nsrecs, uint16_t *nscount,
 220         struct dns_res_rec **additional, uint16_t *arcount)
 221 {
 222         struct ask_forwarder_state *state = tevent_req_data(
 223                 req, struct ask_forwarder_state);
 224         struct dns_name_packet *in_packet = &state->in_packet;
 225         WERROR err;
 226
 227         if (tevent_req_is_werror(req, &err)) {
 228                 return err;
 229         }
 230
 231         *ancount = in_packet->ancount;
 232         *answers = talloc_move(mem_ctx, &in_packet->answers);
 233
 234         *nscount = in_packet->nscount;
 235         *nsrecs = talloc_move(mem_ctx, &in_packet->nsrecs);
 236
 237         *arcount = in_packet->arcount;
 238         *additional = talloc_move(mem_ctx, &in_packet->additional);
 239
 240         return WERR_OK;
 241 }
 242
 243 static WERROR handle_question(struct dns_server *dns,
 244                               TALLOC_CTX *mem_ctx,
 245                               const struct dns_name_question *question,
 246                               struct dns_res_rec **answers, uint16_t *ancount)
 247 {
 248         struct dns_res_rec *ans = *answers;
 249         WERROR werror;
 250         unsigned int ri;
 251         struct dnsp_DnssrvRpcRecord *recs;
 252         uint16_t rec_count, ai = *ancount;
 253         struct ldb_dn *dn = NULL;
 254
 255         werror = dns_name2dn(dns, mem_ctx, question->name, &dn);
 256         W_ERROR_NOT_OK_RETURN(werror);
 257
 258         werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rec_count);
 259         W_ERROR_NOT_OK_RETURN(werror);
 260
 261         ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec, rec_count + ai);
 262         if (ans == NULL) {
 263                 return WERR_NOMEM;
 264         }
 265
 266         for (ri = 0; ri < rec_count; ri++) {
 267                 if ((recs[ri].wType == DNS_TYPE_CNAME) &&
 268                     ((question->question_type == DNS_QTYPE_A) ||
 269                      (question->question_type == DNS_QTYPE_AAAA))) {
 270                         struct dns_name_question *new_q =
 271                                 talloc(mem_ctx, struct dns_name_question);
 272
 273                         if (new_q == NULL) {
 274                                 return WERR_NOMEM;
 275                         }
 276
 277                         /* We reply with one more record, so grow the array */
 278                         ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec,
 279                                              rec_count + 1);
 280                         if (ans == NULL) {
 281                                 TALLOC_FREE(new_q);
 282                                 return WERR_NOMEM;
 283                         }
 284
 285                         /* First put in the CNAME record */
 286                         werror = create_response_rr(question, &recs[ri], &ans, &ai);
 287                         if (!W_ERROR_IS_OK(werror)) {
 288                                 return werror;
 289                         }
 290
 291                         /* And then look up the name it points at.. */
 292
 293                         /* First build up the new question */
 294                         new_q->question_type = question->question_type;
 295                         new_q->question_class = question->question_class;
 296                         if (new_q->question_type == DNS_QTYPE_A) {
 297                                 new_q->name = talloc_strdup(new_q, recs[ri].data.ipv4);
 298                         } else if (new_q->question_type == DNS_QTYPE_AAAA) {
 299                                 new_q->name = talloc_strdup(new_q, recs[ri].data.ipv6);
 300                         }
 301                         if (new_q->name == NULL) {
 302                                 TALLOC_FREE(new_q);
 303                                 return WERR_NOMEM;
 304                         }
 305                         /* and then call the lookup again */
 306                         werror = handle_question(dns, mem_ctx, new_q, &ans, &ai);
 307                         if (!W_ERROR_IS_OK(werror)) {
 308                                 return werror;
 309                         }
 310
 311
 312                         continue;
 313                 }
 314                 if ((question->question_type != DNS_QTYPE_ALL) &&
 315                     (recs[ri].wType != question->question_type)) {
 316                         continue;
 317                 }
 318                 werror = create_response_rr(question, &recs[ri], &ans, &ai);
 319                 if (!W_ERROR_IS_OK(werror)) {
 320                         return werror;
 321                 }
 322         }
 323
 324         if (ai == 0) {
 325                 return DNS_ERR(NAME_ERROR);
 326         }
 327
 328         *ancount = ai;
 329         *answers = ans;
 330
 331         return WERR_OK;
 332 }
 333
 334 static NTSTATUS create_tkey(struct dns_server *dns,
 335                             const char* name,
 336                             const char* algorithm,
 337                             struct dns_server_tkey **tkey)
 338 {
 339         NTSTATUS status;
 340         struct dns_server_tkey_store *store = dns->tkeys;
 341         struct dns_server_tkey *k = talloc_zero(store, struct dns_server_tkey);
 342
 343         if (k == NULL) {
 344                 return NT_STATUS_NO_MEMORY;
 345         }
 346
 347         k->name = talloc_strdup(k, name);
 348
 349         if (k->name  == NULL) {
 350                 return NT_STATUS_NO_MEMORY;
 351         }
 352
 353         k->algorithm = talloc_strdup(k, algorithm);
 354         if (k->algorithm == NULL) {
 355                 return NT_STATUS_NO_MEMORY;
 356         }
 357
 358         status = samba_server_gensec_start(k,
 359                                            dns->task->event_ctx,
 360                                            dns->task->msg_ctx,
 361                                            dns->task->lp_ctx,
 362                                            dns->server_credentials,
 363                                            "dns",
 364                                            &k->gensec);
 365         if (!NT_STATUS_IS_OK(status)) {
 366                 DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
 367                 *tkey = NULL;
 368                 return status;
 369         }
 370
 371         gensec_want_feature(k->gensec, GENSEC_FEATURE_SIGN);
 372
 373         status = gensec_start_mech_by_oid(k->gensec, GENSEC_OID_SPNEGO);
 374
 375         if (!NT_STATUS_IS_OK(status)) {
 376                 DEBUG(1, ("Failed to start GENSEC server code: %s\n",
 377                           nt_errstr(status)));
 378                 *tkey = NULL;
 379                 return status;
 380         }
 381
 382         if (store->tkeys[store->next_idx] != NULL) {
 383                 TALLOC_FREE(store->tkeys[store->next_idx]);
 384         }
 385
 386         store->tkeys[store->next_idx] = k;
 387         (store->next_idx)++;
 388         store->next_idx %= store->size;
 389
 390         *tkey = k;
 391         return NT_STATUS_OK;
 392 }
 393
 394 static NTSTATUS accept_gss_ticket(TALLOC_CTX *mem_ctx,
 395                                   struct dns_server *dns,
 396                                   struct dns_server_tkey *tkey,
 397                                   const DATA_BLOB *key,
 398                                   DATA_BLOB *reply,
 399                                   uint16_t *dns_auth_error)
 400 {
 401         NTSTATUS status;
 402
 403         status = gensec_update(tkey->gensec, mem_ctx, dns->task->event_ctx,
 404                                *key, reply);
 405
 406         if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
 407                 *dns_auth_error = DNS_RCODE_OK;
 408                 return status;
 409         }
 410
 411         if (NT_STATUS_IS_OK(status)) {
 412
 413                 status = gensec_session_info(tkey->gensec, tkey, &tkey->session_info);
 414                 if (!NT_STATUS_IS_OK(status)) {
 415                         *dns_auth_error = DNS_RCODE_BADKEY;
 416                         return status;
 417                 }
 418                 *dns_auth_error = DNS_RCODE_OK;
 419         }
 420
 421         return status;
 422 }
 423
 424 static WERROR handle_tkey(struct dns_server *dns,
 425                           TALLOC_CTX *mem_ctx,
 426                           const struct dns_name_packet *in,
 427                           struct dns_request_state *state,
 428                           struct dns_res_rec **answers,
 429                           uint16_t *ancount)
 430 {
 431         struct dns_res_rec *in_tkey = NULL;
 432         struct dns_res_rec *ret_tkey;
 433         uint16_t i;
 434
 435         for (i = 0; i < in->arcount; i++) {
 436                 if (in->additional[i].rr_type == DNS_QTYPE_TKEY) {
 437                         in_tkey = &in->additional[i];
 438                         break;
 439                 }
 440         }
 441
 442         /* If this is a TKEY query, it should have a TKEY RR.
 443          * Behaviour is not really specified in RFC 2930 or RFC 3645, but
 444          * FORMAT_ERROR seems to be what BIND uses .*/
 445         if (in_tkey == NULL) {
 446                 return DNS_ERR(FORMAT_ERROR);
 447         }
 448
 449         ret_tkey = talloc_zero(mem_ctx, struct dns_res_rec);
 450         if (ret_tkey == NULL) {
 451                 return WERR_NOMEM;
 452         }
 453
 454         ret_tkey->name = talloc_strdup(ret_tkey, in_tkey->name);
 455         if (ret_tkey->name == NULL) {
 456                 return WERR_NOMEM;
 457         }
 458
 459         ret_tkey->rr_type = DNS_QTYPE_TKEY;
 460         ret_tkey->rr_class = DNS_QCLASS_ANY;
 461         ret_tkey->length = UINT16_MAX;
 462
 463         ret_tkey->rdata.tkey_record.algorithm = talloc_strdup(ret_tkey,
 464                         in_tkey->rdata.tkey_record.algorithm);
 465         if (ret_tkey->rdata.tkey_record.algorithm  == NULL) {
 466                 return WERR_NOMEM;
 467         }
 468
 469         ret_tkey->rdata.tkey_record.inception = in_tkey->rdata.tkey_record.inception;
 470         ret_tkey->rdata.tkey_record.expiration = in_tkey->rdata.tkey_record.expiration;
 471         ret_tkey->rdata.tkey_record.mode = in_tkey->rdata.tkey_record.mode;
 472
 473         switch (in_tkey->rdata.tkey_record.mode) {
 474         case DNS_TKEY_MODE_DH:
 475                 /* FIXME: According to RFC 2930, we MUST support this, but we don't.
 476                  * Still, claim it's a bad key instead of a bad mode */
 477                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 478                 break;
 479         case DNS_TKEY_MODE_GSSAPI: {
 480                 NTSTATUS status;
 481                 struct dns_server_tkey *tkey;
 482                 DATA_BLOB key;
 483                 DATA_BLOB reply;
 484
 485                 tkey = dns_find_tkey(dns->tkeys, in->questions[0].name);
 486                 if (tkey != NULL && tkey->complete) {
 487                         /* TODO: check if the key is still valid */
 488                         DEBUG(1, ("Rejecting tkey negotiation for already established key\n"));
 489                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADNAME;
 490                         break;
 491                 }
 492
 493                 if (tkey == NULL) {
 494                         status  = create_tkey(dns, in->questions[0].name,
 495                                               in_tkey->rdata.tkey_record.algorithm,
 496                                               &tkey);
 497                         if (!NT_STATUS_IS_OK(status)) {
 498                                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 499                                 return ntstatus_to_werror(status);
 500                         }
 501                 }
 502
 503                 key.data = in_tkey->rdata.tkey_record.key_data;
 504                 key.length = in_tkey->rdata.tkey_record.key_size;
 505
 506                 status = accept_gss_ticket(ret_tkey, dns, tkey, &key, &reply,
 507                                            &ret_tkey->rdata.tkey_record.error);
 508                 if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 509                         DEBUG(1, ("More processing required\n"));
 510                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 511                 } else if (NT_STATUS_IS_OK(status)) {
 512                         DEBUG(1, ("Tkey handshake completed\n"));
 513                         ret_tkey->rdata.tkey_record.key_size = reply.length;
 514                         ret_tkey->rdata.tkey_record.key_data = talloc_memdup(ret_tkey,
 515                                                                 reply.data,
 516                                                                 reply.length);
 517                         state->sign = true;
 518                         state->key_name = talloc_strdup(mem_ctx, tkey->name);
 519                         if (state->key_name == NULL) {
 520                                 return WERR_NOMEM;
 521                         }
 522                 } else {
 523                         DEBUG(1, ("GSS key negotiation returned %s\n", nt_errstr(status)));
 524                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 525                 }
 526
 527                 break;
 528                 }
 529         case DNS_TKEY_MODE_DELETE:
 530                 /* TODO: implement me */
 531                 DEBUG(1, ("Should delete tkey here\n"));
 532                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_OK;
 533                 break;
 534         case DNS_TKEY_MODE_NULL:
 535         case DNS_TKEY_MODE_SERVER:
 536         case DNS_TKEY_MODE_CLIENT:
 537         case DNS_TKEY_MODE_LAST:
 538                 /* We don't have to implement these, return a mode error */
 539                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADMODE;
 540                 break;
 541         default:
 542                 DEBUG(1, ("Unsupported TKEY mode %d\n",
 543                       in_tkey->rdata.tkey_record.mode));
 544         }
 545
 546         *answers = ret_tkey;
 547         *ancount = 1;
 548
 549         return WERR_OK;
 550 }
 551
 552 struct dns_server_process_query_state {
 553         struct dns_res_rec *answers;
 554         uint16_t ancount;
 555         struct dns_res_rec *nsrecs;
 556         uint16_t nscount;
 557         struct dns_res_rec *additional;
 558         uint16_t arcount;
 559 };
 560
 561 static void dns_server_process_query_got_response(struct tevent_req *subreq);
 562
 563 struct tevent_req *dns_server_process_query_send(
 564         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 565         struct dns_server *dns, struct dns_request_state *req_state,
 566         const struct dns_name_packet *in)
 567 {
 568         struct tevent_req *req, *subreq;
 569         struct dns_server_process_query_state *state;
 570
 571         req = tevent_req_create(mem_ctx, &state,
 572                                 struct dns_server_process_query_state);
 573         if (req == NULL) {
 574                 return NULL;
 575         }
 576         if (in->qdcount != 1) {
 577                 tevent_req_werror(req, DNS_ERR(FORMAT_ERROR));
 578                 return tevent_req_post(req, ev);
 579         }
 580
 581         /* Windows returns NOT_IMPLEMENTED on this as well */
 582         if (in->questions[0].question_class == DNS_QCLASS_NONE) {
 583                 tevent_req_werror(req, DNS_ERR(NOT_IMPLEMENTED));
 584                 return tevent_req_post(req, ev);
 585         }
 586
 587         if (in->questions[0].question_type == DNS_QTYPE_TKEY) {
 588                 WERROR err;
 589
 590                 err = handle_tkey(dns, state, in, req_state,
 591                                   &state->answers, &state->ancount);
 592                 if (tevent_req_werror(req, err)) {
 593                         return tevent_req_post(req, ev);
 594                 }
 595                 tevent_req_done(req);
 596                 return tevent_req_post(req, ev);
 597         }
 598
 599         if (dns_authorative_for_zone(dns, in->questions[0].name)) {
 600                 WERROR err;
 601
 602                 req_state->flags |= DNS_FLAG_AUTHORITATIVE;
 603                 err = handle_question(dns, state, &in->questions[0],
 604                                       &state->answers, &state->ancount);
 605                 if (tevent_req_werror(req, err)) {
 606                         return tevent_req_post(req, ev);
 607                 }
 608                 tevent_req_done(req);
 609                 return tevent_req_post(req, ev);
 610         }
 611
 612         if ((req_state->flags & DNS_FLAG_RECURSION_DESIRED) &&
 613             (req_state->flags & DNS_FLAG_RECURSION_AVAIL)) {
 614                 DEBUG(2, ("Not authoritative for '%s', forwarding\n",
 615                           in->questions[0].name));
 616
 617                 subreq = ask_forwarder_send(
 618                         state, ev, lpcfg_dns_forwarder(dns->task->lp_ctx),
 619                         &in->questions[0]);
 620                 if (tevent_req_nomem(subreq, req)) {
 621                         return tevent_req_post(req, ev);
 622                 }
 623                 tevent_req_set_callback(
 624                         subreq, dns_server_process_query_got_response, req);
 625                 return req;
 626         }
 627
 628         tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 629         return tevent_req_post(req, ev);
 630 }
 631
 632 static void dns_server_process_query_got_response(struct tevent_req *subreq)
 633 {
 634         struct tevent_req *req = tevent_req_callback_data(
 635                 subreq, struct tevent_req);
 636         struct dns_server_process_query_state *state = tevent_req_data(
 637                 req, struct dns_server_process_query_state);
 638         WERROR err;
 639
 640         err = ask_forwarder_recv(subreq, state,
 641                                  &state->answers, &state->ancount,
 642                                  &state->nsrecs, &state->nscount,
 643                                  &state->additional, &state->arcount);
 644         TALLOC_FREE(subreq);
 645         if (tevent_req_werror(req, err)) {
 646                 return;
 647         }
 648         tevent_req_done(req);
 649 }
 650
 651 WERROR dns_server_process_query_recv(
 652         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 653         struct dns_res_rec **answers,    uint16_t *ancount,
 654         struct dns_res_rec **nsrecs,     uint16_t *nscount,
 655         struct dns_res_rec **additional, uint16_t *arcount)
 656 {
 657         struct dns_server_process_query_state *state = tevent_req_data(
 658                 req, struct dns_server_process_query_state);
 659         WERROR err;
 660
 661         if (tevent_req_is_werror(req, &err)) {
 662                 return err;
 663         }
 664         *answers = talloc_move(mem_ctx, &state->answers);
 665         *ancount = state->ancount;
 666         *nsrecs = talloc_move(mem_ctx, &state->nsrecs);
 667         *nscount = state->nscount;
 668         *additional = talloc_move(mem_ctx, &state->additional);
 669         *arcount = state->arcount;
 670         return WERR_OK;
 671 }