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         struct dns_server *dns,
 142         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 143         const char *forwarder, struct dns_name_question *question)
 144 {
 145         struct tevent_req *req, *subreq;
 146         struct ask_forwarder_state *state;
 147         struct dns_res_rec *options;
 148         struct dns_name_packet out_packet = { 0, };
 149         DATA_BLOB out_blob;
 150         enum ndr_err_code ndr_err;
 151         WERROR werr;
 152
 153         req = tevent_req_create(mem_ctx, &state, struct ask_forwarder_state);
 154         if (req == NULL) {
 155                 return NULL;
 156         }
 157         state->ev = ev;
 158         generate_random_buffer((uint8_t *)&state->id, sizeof(state->id));
 159
 160         if (!is_ipaddress(forwarder)) {
 161                 DEBUG(0, ("Invalid 'dns forwarder' setting '%s', needs to be "
 162                           "an IP address\n", forwarder));
 163                 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 164                 return tevent_req_post(req, ev);
 165         }
 166
 167         out_packet.id = state->id;
 168         out_packet.operation |= DNS_OPCODE_QUERY | DNS_FLAG_RECURSION_DESIRED;
 169         out_packet.qdcount = 1;
 170         out_packet.questions = question;
 171
 172         werr = dns_generate_options(dns, state, &options);
 173         if (!W_ERROR_IS_OK(werr)) {
 174                 tevent_req_werror(req, werr);
 175                 return tevent_req_post(req, ev);
 176         }
 177
 178         out_packet.arcount = 1;
 179         out_packet.additional = options;
 180
 181         ndr_err = ndr_push_struct_blob(
 182                 &out_blob, state, &out_packet,
 183                 (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 184         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 185                 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
 186                 return tevent_req_post(req, ev);
 187         }
 188         subreq = dns_udp_request_send(state, ev, forwarder, out_blob.data,
 189                                       out_blob.length);
 190         if (tevent_req_nomem(subreq, req)) {
 191                 return tevent_req_post(req, ev);
 192         }
 193         tevent_req_set_callback(subreq, ask_forwarder_done, req);
 194         return req;
 195 }
 196
 197 static void ask_forwarder_done(struct tevent_req *subreq)
 198 {
 199         struct tevent_req *req = tevent_req_callback_data(
 200                 subreq, struct tevent_req);
 201         struct ask_forwarder_state *state = tevent_req_data(
 202                 req, struct ask_forwarder_state);
 203         DATA_BLOB in_blob;
 204         enum ndr_err_code ndr_err;
 205         WERROR ret;
 206
 207         ret = dns_udp_request_recv(subreq, state,
 208                                    &in_blob.data, &in_blob.length);
 209         TALLOC_FREE(subreq);
 210         if (tevent_req_werror(req, ret)) {
 211                 return;
 212         }
 213
 214         ndr_err = ndr_pull_struct_blob(
 215                 &in_blob, state, &state->in_packet,
 216                 (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 217         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 218                 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
 219                 return;
 220         }
 221         if (state->in_packet.id != state->id) {
 222                 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 223                 return;
 224         }
 225         tevent_req_done(req);
 226 }
 227
 228 static WERROR ask_forwarder_recv(
 229         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 230         struct dns_res_rec **answers, uint16_t *ancount,
 231         struct dns_res_rec **nsrecs, uint16_t *nscount,
 232         struct dns_res_rec **additional, uint16_t *arcount)
 233 {
 234         struct ask_forwarder_state *state = tevent_req_data(
 235                 req, struct ask_forwarder_state);
 236         struct dns_name_packet *in_packet = &state->in_packet;
 237         WERROR err;
 238
 239         if (tevent_req_is_werror(req, &err)) {
 240                 return err;
 241         }
 242
 243         *ancount = in_packet->ancount;
 244         *answers = talloc_move(mem_ctx, &in_packet->answers);
 245
 246         *nscount = in_packet->nscount;
 247         *nsrecs = talloc_move(mem_ctx, &in_packet->nsrecs);
 248
 249         *arcount = in_packet->arcount;
 250         *additional = talloc_move(mem_ctx, &in_packet->additional);
 251
 252         return WERR_OK;
 253 }
 254
 255 static WERROR handle_question(struct dns_server *dns,
 256                               TALLOC_CTX *mem_ctx,
 257                               const struct dns_name_question *question,
 258                               struct dns_res_rec **answers, uint16_t *ancount)
 259 {
 260         struct dns_res_rec *ans = *answers;
 261         WERROR werror;
 262         unsigned int ri;
 263         struct dnsp_DnssrvRpcRecord *recs;
 264         uint16_t rec_count, ai = *ancount;
 265         struct ldb_dn *dn = NULL;
 266
 267         werror = dns_name2dn(dns, mem_ctx, question->name, &dn);
 268         W_ERROR_NOT_OK_RETURN(werror);
 269
 270         werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rec_count);
 271         W_ERROR_NOT_OK_RETURN(werror);
 272
 273         ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec, rec_count + ai);
 274         if (ans == NULL) {
 275                 return WERR_NOMEM;
 276         }
 277
 278         for (ri = 0; ri < rec_count; ri++) {
 279                 if ((recs[ri].wType == DNS_TYPE_CNAME) &&
 280                     ((question->question_type == DNS_QTYPE_A) ||
 281                      (question->question_type == DNS_QTYPE_AAAA))) {
 282                         struct dns_name_question *new_q =
 283                                 talloc(mem_ctx, struct dns_name_question);
 284
 285                         if (new_q == NULL) {
 286                                 return WERR_NOMEM;
 287                         }
 288
 289                         /* We reply with one more record, so grow the array */
 290                         ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec,
 291                                              rec_count + 1);
 292                         if (ans == NULL) {
 293                                 TALLOC_FREE(new_q);
 294                                 return WERR_NOMEM;
 295                         }
 296
 297                         /* First put in the CNAME record */
 298                         werror = create_response_rr(question, &recs[ri], &ans, &ai);
 299                         if (!W_ERROR_IS_OK(werror)) {
 300                                 return werror;
 301                         }
 302
 303                         /* And then look up the name it points at.. */
 304
 305                         /* First build up the new question */
 306                         new_q->question_type = question->question_type;
 307                         new_q->question_class = question->question_class;
 308                         if (new_q->question_type == DNS_QTYPE_A) {
 309                                 new_q->name = talloc_strdup(new_q, recs[ri].data.ipv4);
 310                         } else if (new_q->question_type == DNS_QTYPE_AAAA) {
 311                                 new_q->name = talloc_strdup(new_q, recs[ri].data.ipv6);
 312                         }
 313                         if (new_q->name == NULL) {
 314                                 TALLOC_FREE(new_q);
 315                                 return WERR_NOMEM;
 316                         }
 317                         /* and then call the lookup again */
 318                         werror = handle_question(dns, mem_ctx, new_q, &ans, &ai);
 319                         if (!W_ERROR_IS_OK(werror)) {
 320                                 return werror;
 321                         }
 322
 323
 324                         continue;
 325                 }
 326                 if ((question->question_type != DNS_QTYPE_ALL) &&
 327                     (recs[ri].wType != question->question_type)) {
 328                         continue;
 329                 }
 330                 werror = create_response_rr(question, &recs[ri], &ans, &ai);
 331                 if (!W_ERROR_IS_OK(werror)) {
 332                         return werror;
 333                 }
 334         }
 335
 336         if (ai == 0) {
 337                 return DNS_ERR(NAME_ERROR);
 338         }
 339
 340         *ancount = ai;
 341         *answers = ans;
 342
 343         return WERR_OK;
 344 }
 345
 346 static NTSTATUS create_tkey(struct dns_server *dns,
 347                             const char* name,
 348                             const char* algorithm,
 349                             struct dns_server_tkey **tkey)
 350 {
 351         NTSTATUS status;
 352         struct dns_server_tkey_store *store = dns->tkeys;
 353         struct dns_server_tkey *k = talloc_zero(store, struct dns_server_tkey);
 354
 355         if (k == NULL) {
 356                 return NT_STATUS_NO_MEMORY;
 357         }
 358
 359         k->name = talloc_strdup(k, name);
 360
 361         if (k->name  == NULL) {
 362                 return NT_STATUS_NO_MEMORY;
 363         }
 364
 365         k->algorithm = talloc_strdup(k, algorithm);
 366         if (k->algorithm == NULL) {
 367                 return NT_STATUS_NO_MEMORY;
 368         }
 369
 370         status = samba_server_gensec_start(k,
 371                                            dns->task->event_ctx,
 372                                            dns->task->msg_ctx,
 373                                            dns->task->lp_ctx,
 374                                            dns->server_credentials,
 375                                            "dns",
 376                                            &k->gensec);
 377         if (!NT_STATUS_IS_OK(status)) {
 378                 DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
 379                 *tkey = NULL;
 380                 return status;
 381         }
 382
 383         gensec_want_feature(k->gensec, GENSEC_FEATURE_SIGN);
 384
 385         status = gensec_start_mech_by_oid(k->gensec, GENSEC_OID_SPNEGO);
 386
 387         if (!NT_STATUS_IS_OK(status)) {
 388                 DEBUG(1, ("Failed to start GENSEC server code: %s\n",
 389                           nt_errstr(status)));
 390                 *tkey = NULL;
 391                 return status;
 392         }
 393
 394         if (store->tkeys[store->next_idx] != NULL) {
 395                 TALLOC_FREE(store->tkeys[store->next_idx]);
 396         }
 397
 398         store->tkeys[store->next_idx] = k;
 399         (store->next_idx)++;
 400         store->next_idx %= store->size;
 401
 402         *tkey = k;
 403         return NT_STATUS_OK;
 404 }
 405
 406 static NTSTATUS accept_gss_ticket(TALLOC_CTX *mem_ctx,
 407                                   struct dns_server *dns,
 408                                   struct dns_server_tkey *tkey,
 409                                   const DATA_BLOB *key,
 410                                   DATA_BLOB *reply,
 411                                   uint16_t *dns_auth_error)
 412 {
 413         NTSTATUS status;
 414
 415         status = gensec_update(tkey->gensec, mem_ctx, dns->task->event_ctx,
 416                                *key, reply);
 417
 418         if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
 419                 *dns_auth_error = DNS_RCODE_OK;
 420                 return status;
 421         }
 422
 423         if (NT_STATUS_IS_OK(status)) {
 424
 425                 status = gensec_session_info(tkey->gensec, tkey, &tkey->session_info);
 426                 if (!NT_STATUS_IS_OK(status)) {
 427                         *dns_auth_error = DNS_RCODE_BADKEY;
 428                         return status;
 429                 }
 430                 *dns_auth_error = DNS_RCODE_OK;
 431         }
 432
 433         return status;
 434 }
 435
 436 static WERROR handle_tkey(struct dns_server *dns,
 437                           TALLOC_CTX *mem_ctx,
 438                           const struct dns_name_packet *in,
 439                           struct dns_request_state *state,
 440                           struct dns_res_rec **answers,
 441                           uint16_t *ancount)
 442 {
 443         struct dns_res_rec *in_tkey = NULL;
 444         struct dns_res_rec *ret_tkey;
 445         uint16_t i;
 446
 447         for (i = 0; i < in->arcount; i++) {
 448                 if (in->additional[i].rr_type == DNS_QTYPE_TKEY) {
 449                         in_tkey = &in->additional[i];
 450                         break;
 451                 }
 452         }
 453
 454         /* If this is a TKEY query, it should have a TKEY RR.
 455          * Behaviour is not really specified in RFC 2930 or RFC 3645, but
 456          * FORMAT_ERROR seems to be what BIND uses .*/
 457         if (in_tkey == NULL) {
 458                 return DNS_ERR(FORMAT_ERROR);
 459         }
 460
 461         ret_tkey = talloc_zero(mem_ctx, struct dns_res_rec);
 462         if (ret_tkey == NULL) {
 463                 return WERR_NOMEM;
 464         }
 465
 466         ret_tkey->name = talloc_strdup(ret_tkey, in_tkey->name);
 467         if (ret_tkey->name == NULL) {
 468                 return WERR_NOMEM;
 469         }
 470
 471         ret_tkey->rr_type = DNS_QTYPE_TKEY;
 472         ret_tkey->rr_class = DNS_QCLASS_ANY;
 473         ret_tkey->length = UINT16_MAX;
 474
 475         ret_tkey->rdata.tkey_record.algorithm = talloc_strdup(ret_tkey,
 476                         in_tkey->rdata.tkey_record.algorithm);
 477         if (ret_tkey->rdata.tkey_record.algorithm  == NULL) {
 478                 return WERR_NOMEM;
 479         }
 480
 481         ret_tkey->rdata.tkey_record.inception = in_tkey->rdata.tkey_record.inception;
 482         ret_tkey->rdata.tkey_record.expiration = in_tkey->rdata.tkey_record.expiration;
 483         ret_tkey->rdata.tkey_record.mode = in_tkey->rdata.tkey_record.mode;
 484
 485         switch (in_tkey->rdata.tkey_record.mode) {
 486         case DNS_TKEY_MODE_DH:
 487                 /* FIXME: According to RFC 2930, we MUST support this, but we don't.
 488                  * Still, claim it's a bad key instead of a bad mode */
 489                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 490                 break;
 491         case DNS_TKEY_MODE_GSSAPI: {
 492                 NTSTATUS status;
 493                 struct dns_server_tkey *tkey;
 494                 DATA_BLOB key;
 495                 DATA_BLOB reply;
 496
 497                 tkey = dns_find_tkey(dns->tkeys, in->questions[0].name);
 498                 if (tkey != NULL && tkey->complete) {
 499                         /* TODO: check if the key is still valid */
 500                         DEBUG(1, ("Rejecting tkey negotiation for already established key\n"));
 501                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADNAME;
 502                         break;
 503                 }
 504
 505                 if (tkey == NULL) {
 506                         status  = create_tkey(dns, in->questions[0].name,
 507                                               in_tkey->rdata.tkey_record.algorithm,
 508                                               &tkey);
 509                         if (!NT_STATUS_IS_OK(status)) {
 510                                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 511                                 return ntstatus_to_werror(status);
 512                         }
 513                 }
 514
 515                 key.data = in_tkey->rdata.tkey_record.key_data;
 516                 key.length = in_tkey->rdata.tkey_record.key_size;
 517
 518                 status = accept_gss_ticket(ret_tkey, dns, tkey, &key, &reply,
 519                                            &ret_tkey->rdata.tkey_record.error);
 520                 if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 521                         DEBUG(1, ("More processing required\n"));
 522                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 523                 } else if (NT_STATUS_IS_OK(status)) {
 524                         DEBUG(1, ("Tkey handshake completed\n"));
 525                         ret_tkey->rdata.tkey_record.key_size = reply.length;
 526                         ret_tkey->rdata.tkey_record.key_data = talloc_memdup(ret_tkey,
 527                                                                 reply.data,
 528                                                                 reply.length);
 529                         state->sign = true;
 530                         state->key_name = talloc_strdup(mem_ctx, tkey->name);
 531                         if (state->key_name == NULL) {
 532                                 return WERR_NOMEM;
 533                         }
 534                 } else {
 535                         DEBUG(1, ("GSS key negotiation returned %s\n", nt_errstr(status)));
 536                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 537                 }
 538
 539                 break;
 540                 }
 541         case DNS_TKEY_MODE_DELETE:
 542                 /* TODO: implement me */
 543                 DEBUG(1, ("Should delete tkey here\n"));
 544                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_OK;
 545                 break;
 546         case DNS_TKEY_MODE_NULL:
 547         case DNS_TKEY_MODE_SERVER:
 548         case DNS_TKEY_MODE_CLIENT:
 549         case DNS_TKEY_MODE_LAST:
 550                 /* We don't have to implement these, return a mode error */
 551                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADMODE;
 552                 break;
 553         default:
 554                 DEBUG(1, ("Unsupported TKEY mode %d\n",
 555                       in_tkey->rdata.tkey_record.mode));
 556         }
 557
 558         *answers = ret_tkey;
 559         *ancount = 1;
 560
 561         return WERR_OK;
 562 }
 563
 564 struct dns_server_process_query_state {
 565         struct dns_res_rec *answers;
 566         uint16_t ancount;
 567         struct dns_res_rec *nsrecs;
 568         uint16_t nscount;
 569         struct dns_res_rec *additional;
 570         uint16_t arcount;
 571 };
 572
 573 static void dns_server_process_query_got_response(struct tevent_req *subreq);
 574
 575 struct tevent_req *dns_server_process_query_send(
 576         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 577         struct dns_server *dns, struct dns_request_state *req_state,
 578         const struct dns_name_packet *in)
 579 {
 580         struct tevent_req *req, *subreq;
 581         struct dns_server_process_query_state *state;
 582
 583         req = tevent_req_create(mem_ctx, &state,
 584                                 struct dns_server_process_query_state);
 585         if (req == NULL) {
 586                 return NULL;
 587         }
 588         if (in->qdcount != 1) {
 589                 tevent_req_werror(req, DNS_ERR(FORMAT_ERROR));
 590                 return tevent_req_post(req, ev);
 591         }
 592
 593         /* Windows returns NOT_IMPLEMENTED on this as well */
 594         if (in->questions[0].question_class == DNS_QCLASS_NONE) {
 595                 tevent_req_werror(req, DNS_ERR(NOT_IMPLEMENTED));
 596                 return tevent_req_post(req, ev);
 597         }
 598
 599         if (in->questions[0].question_type == DNS_QTYPE_TKEY) {
 600                 WERROR err;
 601
 602                 err = handle_tkey(dns, state, in, req_state,
 603                                   &state->answers, &state->ancount);
 604                 if (tevent_req_werror(req, err)) {
 605                         return tevent_req_post(req, ev);
 606                 }
 607                 tevent_req_done(req);
 608                 return tevent_req_post(req, ev);
 609         }
 610
 611         if (dns_authorative_for_zone(dns, in->questions[0].name)) {
 612                 WERROR err;
 613
 614                 req_state->flags |= DNS_FLAG_AUTHORITATIVE;
 615                 err = handle_question(dns, state, &in->questions[0],
 616                                       &state->answers, &state->ancount);
 617                 if (tevent_req_werror(req, err)) {
 618                         return tevent_req_post(req, ev);
 619                 }
 620                 tevent_req_done(req);
 621                 return tevent_req_post(req, ev);
 622         }
 623
 624         if ((req_state->flags & DNS_FLAG_RECURSION_DESIRED) &&
 625             (req_state->flags & DNS_FLAG_RECURSION_AVAIL)) {
 626                 DEBUG(2, ("Not authoritative for '%s', forwarding\n",
 627                           in->questions[0].name));
 628
 629                 subreq = ask_forwarder_send(
 630                         dns,
 631                         state, ev, lpcfg_dns_forwarder(dns->task->lp_ctx),
 632                         &in->questions[0]);
 633                 if (tevent_req_nomem(subreq, req)) {
 634                         return tevent_req_post(req, ev);
 635                 }
 636                 tevent_req_set_callback(
 637                         subreq, dns_server_process_query_got_response, req);
 638                 return req;
 639         }
 640
 641         tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 642         return tevent_req_post(req, ev);
 643 }
 644
 645 static void dns_server_process_query_got_response(struct tevent_req *subreq)
 646 {
 647         struct tevent_req *req = tevent_req_callback_data(
 648                 subreq, struct tevent_req);
 649         struct dns_server_process_query_state *state = tevent_req_data(
 650                 req, struct dns_server_process_query_state);
 651         WERROR err;
 652
 653         err = ask_forwarder_recv(subreq, state,
 654                                  &state->answers, &state->ancount,
 655                                  &state->nsrecs, &state->nscount,
 656                                  &state->additional, &state->arcount);
 657         TALLOC_FREE(subreq);
 658         if (tevent_req_werror(req, err)) {
 659                 return;
 660         }
 661         tevent_req_done(req);
 662 }
 663
 664 WERROR dns_server_process_query_recv(
 665         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 666         struct dns_res_rec **answers,    uint16_t *ancount,
 667         struct dns_res_rec **nsrecs,     uint16_t *nscount,
 668         struct dns_res_rec **additional, uint16_t *arcount)
 669 {
 670         struct dns_server_process_query_state *state = tevent_req_data(
 671                 req, struct dns_server_process_query_state);
 672         WERROR err;
 673
 674         if (tevent_req_is_werror(req, &err)) {
 675                 return err;
 676         }
 677         *answers = talloc_move(mem_ctx, &state->answers);
 678         *ancount = state->ancount;
 679         *nsrecs = talloc_move(mem_ctx, &state->nsrecs);
 680         *nscount = state->nscount;
 681         *additional = talloc_move(mem_ctx, &state->additional);
 682         *arcount = state->arcount;
 683         return WERR_OK;
 684 }