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 char *name,
  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                 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ptr_record);
  95                 break;
  96         case DNS_QTYPE_MX:
  97                 ans[ai].rdata.mx_record.preference = rec->data.mx.wPriority;
  98                 ans[ai].rdata.mx_record.exchange = talloc_strdup(
  99                         ans, rec->data.mx.nameTarget);
 100                 if (ans[ai].rdata.mx_record.exchange == NULL) {
 101                         return WERR_NOMEM;
 102                 }
 103                 break;
 104         case DNS_QTYPE_TXT:
 105                 tmp = talloc_asprintf(ans, "\"%s\"", rec->data.txt.str[0]);
 106                 W_ERROR_HAVE_NO_MEMORY(tmp);
 107                 for (i=1; i<rec->data.txt.count; i++) {
 108                         tmp = talloc_asprintf_append_buffer(
 109                                 tmp, " \"%s\"", rec->data.txt.str[i]);
 110                         W_ERROR_HAVE_NO_MEMORY(tmp);
 111                 }
 112                 ans[ai].rdata.txt_record.txt = tmp;
 113                 break;
 114         default:
 115                 DEBUG(0, ("Got unhandled type %u query.\n", rec->wType));
 116                 return DNS_ERR(NOT_IMPLEMENTED);
 117         }
 118
 119         ans[ai].name = talloc_strdup(ans, name);
 120         W_ERROR_HAVE_NO_MEMORY(ans[ai].name);
 121         ans[ai].rr_type = rec->wType;
 122         ans[ai].rr_class = DNS_QCLASS_IN;
 123         ans[ai].ttl = rec->dwTtlSeconds;
 124         ans[ai].length = UINT16_MAX;
 125         ai++;
 126
 127         *answers = ans;
 128         *ancount = ai;
 129
 130         return WERR_OK;
 131 }
 132
 133 struct ask_forwarder_state {
 134         struct tevent_context *ev;
 135         uint16_t id;
 136         struct dns_name_packet in_packet;
 137 };
 138
 139 static void ask_forwarder_done(struct tevent_req *subreq);
 140
 141 static struct tevent_req *ask_forwarder_send(
 142         struct dns_server *dns,
 143         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 144         const char *forwarder, struct dns_name_question *question)
 145 {
 146         struct tevent_req *req, *subreq;
 147         struct ask_forwarder_state *state;
 148         struct dns_res_rec *options;
 149         struct dns_name_packet out_packet = { 0, };
 150         DATA_BLOB out_blob;
 151         enum ndr_err_code ndr_err;
 152         WERROR werr;
 153
 154         req = tevent_req_create(mem_ctx, &state, struct ask_forwarder_state);
 155         if (req == NULL) {
 156                 return NULL;
 157         }
 158         state->ev = ev;
 159         generate_random_buffer((uint8_t *)&state->id, sizeof(state->id));
 160
 161         if (!is_ipaddress(forwarder)) {
 162                 DEBUG(0, ("Invalid 'dns forwarder' setting '%s', needs to be "
 163                           "an IP address\n", forwarder));
 164                 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 165                 return tevent_req_post(req, ev);
 166         }
 167
 168         out_packet.id = state->id;
 169         out_packet.operation |= DNS_OPCODE_QUERY | DNS_FLAG_RECURSION_DESIRED;
 170         out_packet.qdcount = 1;
 171         out_packet.questions = question;
 172
 173         werr = dns_generate_options(dns, state, &options);
 174         if (!W_ERROR_IS_OK(werr)) {
 175                 tevent_req_werror(req, werr);
 176                 return tevent_req_post(req, ev);
 177         }
 178
 179         out_packet.arcount = 1;
 180         out_packet.additional = options;
 181
 182         ndr_err = ndr_push_struct_blob(
 183                 &out_blob, state, &out_packet,
 184                 (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 185         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 186                 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
 187                 return tevent_req_post(req, ev);
 188         }
 189         subreq = dns_udp_request_send(state, ev, forwarder, out_blob.data,
 190                                       out_blob.length);
 191         if (tevent_req_nomem(subreq, req)) {
 192                 return tevent_req_post(req, ev);
 193         }
 194         tevent_req_set_callback(subreq, ask_forwarder_done, req);
 195         return req;
 196 }
 197
 198 static void ask_forwarder_done(struct tevent_req *subreq)
 199 {
 200         struct tevent_req *req = tevent_req_callback_data(
 201                 subreq, struct tevent_req);
 202         struct ask_forwarder_state *state = tevent_req_data(
 203                 req, struct ask_forwarder_state);
 204         DATA_BLOB in_blob;
 205         enum ndr_err_code ndr_err;
 206         int ret;
 207
 208         ret = dns_udp_request_recv(subreq, state,
 209                                    &in_blob.data, &in_blob.length);
 210         TALLOC_FREE(subreq);
 211
 212         if (ret != 0) {
 213                 tevent_req_werror(req, unix_to_werror(ret));
 214                 return;
 215         }
 216
 217         ndr_err = ndr_pull_struct_blob(
 218                 &in_blob, state, &state->in_packet,
 219                 (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 220         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 221                 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
 222                 return;
 223         }
 224         if (state->in_packet.id != state->id) {
 225                 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 226                 return;
 227         }
 228         tevent_req_done(req);
 229 }
 230
 231 static WERROR ask_forwarder_recv(
 232         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 233         struct dns_res_rec **answers, uint16_t *ancount,
 234         struct dns_res_rec **nsrecs, uint16_t *nscount,
 235         struct dns_res_rec **additional, uint16_t *arcount)
 236 {
 237         struct ask_forwarder_state *state = tevent_req_data(
 238                 req, struct ask_forwarder_state);
 239         struct dns_name_packet *in_packet = &state->in_packet;
 240         WERROR err;
 241
 242         if (tevent_req_is_werror(req, &err)) {
 243                 return err;
 244         }
 245
 246         *ancount = in_packet->ancount;
 247         *answers = talloc_move(mem_ctx, &in_packet->answers);
 248
 249         *nscount = in_packet->nscount;
 250         *nsrecs = talloc_move(mem_ctx, &in_packet->nsrecs);
 251
 252         *arcount = in_packet->arcount;
 253         *additional = talloc_move(mem_ctx, &in_packet->additional);
 254
 255         return WERR_OK;
 256 }
 257
 258 static WERROR add_zone_authority_record(struct dns_server *dns,
 259                                         TALLOC_CTX *mem_ctx,
 260                                         const struct dns_name_question *question,
 261                                         struct dns_res_rec **nsrecs, uint16_t *nscount)
 262 {
 263         const char *zone = NULL;
 264         struct dnsp_DnssrvRpcRecord *recs;
 265         struct dns_res_rec *ns = *nsrecs;
 266         uint16_t rec_count, ni = *nscount;
 267         struct ldb_dn *dn = NULL;
 268         unsigned int ri;
 269         WERROR werror;
 270
 271         zone = dns_get_authoritative_zone(dns, question->name);
 272         DEBUG(10, ("Creating zone authority record for '%s'\n", zone));
 273
 274         werror = dns_name2dn(dns, mem_ctx, zone, &dn);
 275         if (!W_ERROR_IS_OK(werror)) {
 276                 return werror;
 277         }
 278
 279         werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rec_count);
 280         if (!W_ERROR_IS_OK(werror)) {
 281                 return werror;
 282         }
 283
 284         ns = talloc_realloc(mem_ctx, ns, struct dns_res_rec, rec_count + ni);
 285         if (ns == NULL) {
 286                 return WERR_NOMEM;
 287         }
 288         for (ri = 0; ri < rec_count; ri++) {
 289                 if (recs[ri].wType == DNS_TYPE_SOA) {
 290                         werror = create_response_rr(zone, &recs[ri], &ns, &ni);
 291                         if (!W_ERROR_IS_OK(werror)) {
 292                                 return werror;
 293                         }
 294                 }
 295         }
 296
 297         *nscount = ni;
 298         *nsrecs = ns;
 299
 300         return WERR_OK;
 301 }
 302
 303
 304 static WERROR handle_question(struct dns_server *dns,
 305                               TALLOC_CTX *mem_ctx,
 306                               const struct dns_name_question *question,
 307                               struct dns_res_rec **answers, uint16_t *ancount,
 308                               struct dns_res_rec **nsrecs, uint16_t *nscount)
 309 {
 310         struct dns_res_rec *ans = *answers;
 311         struct dns_res_rec *ns = *nsrecs;
 312         WERROR werror, werror_return;
 313         unsigned int ri;
 314         struct dnsp_DnssrvRpcRecord *recs;
 315         uint16_t rec_count, ai = *ancount, ni = *nscount;
 316         struct ldb_dn *dn = NULL;
 317
 318         werror = dns_name2dn(dns, mem_ctx, question->name, &dn);
 319         if (!W_ERROR_IS_OK(werror)) {
 320                 return werror;
 321         }
 322
 323         werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rec_count);
 324         if (!W_ERROR_IS_OK(werror)) {
 325                 werror_return = werror;
 326                 goto done;
 327         }
 328
 329         ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec, rec_count + ai);
 330         if (ans == NULL) {
 331                 return WERR_NOMEM;
 332         }
 333
 334         /* Set up for an NXDOMAIN reply if no match is found */
 335         werror_return = DNS_ERR(NAME_ERROR);
 336
 337         for (ri = 0; ri < rec_count; ri++) {
 338                 if ((recs[ri].wType == DNS_TYPE_CNAME) &&
 339                     ((question->question_type == DNS_QTYPE_A) ||
 340                      (question->question_type == DNS_QTYPE_AAAA))) {
 341                         struct dns_name_question *new_q =
 342                                 talloc(mem_ctx, struct dns_name_question);
 343
 344                         if (new_q == NULL) {
 345                                 return WERR_NOMEM;
 346                         }
 347
 348                         /* We reply with one more record, so grow the array */
 349                         ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec,
 350                                              rec_count + 1);
 351                         if (ans == NULL) {
 352                                 TALLOC_FREE(new_q);
 353                                 return WERR_NOMEM;
 354                         }
 355
 356                         /* First put in the CNAME record */
 357                         werror = create_response_rr(question->name, &recs[ri], &ans, &ai);
 358                         if (!W_ERROR_IS_OK(werror)) {
 359                                 TALLOC_FREE(new_q);
 360                                 return werror;
 361                         }
 362
 363                         /* And then look up the name it points at.. */
 364
 365                         /* First build up the new question */
 366                         new_q->question_type = question->question_type;
 367                         new_q->question_class = question->question_class;
 368                         new_q->name = talloc_strdup(new_q, recs[ri].data.cname);
 369                         if (new_q->name == NULL) {
 370                                 TALLOC_FREE(new_q);
 371                                 return WERR_NOMEM;
 372                         }
 373                         /* and then call the lookup again */
 374                         werror = handle_question(dns, mem_ctx, new_q, &ans, &ai, &ns, &ni);
 375                         if (!W_ERROR_IS_OK(werror)) {
 376                                 goto done;
 377                         }
 378                         werror_return = WERR_OK;
 379
 380
 381                         continue;
 382                 }
 383                 if ((question->question_type != DNS_QTYPE_ALL) &&
 384                     (recs[ri].wType != (enum dns_record_type) question->question_type)) {
 385                         werror_return = WERR_OK;
 386                         continue;
 387                 }
 388                 werror = create_response_rr(question->name, &recs[ri], &ans, &ai);
 389                 if (!W_ERROR_IS_OK(werror)) {
 390                         return werror;
 391                 }
 392                 werror_return = WERR_OK;
 393         }
 394
 395 done:
 396         /* Always add an authority record to replies we should know about */
 397         add_zone_authority_record(dns, mem_ctx, question, &ns, &ni);
 398
 399         *ancount = ai;
 400         *answers = ans;
 401         *nscount = ni;
 402         *nsrecs = ns;
 403
 404         return werror_return;
 405 }
 406
 407 static NTSTATUS create_tkey(struct dns_server *dns,
 408                             const char* name,
 409                             const char* algorithm,
 410                             struct dns_server_tkey **tkey)
 411 {
 412         NTSTATUS status;
 413         struct dns_server_tkey_store *store = dns->tkeys;
 414         struct dns_server_tkey *k = talloc_zero(store, struct dns_server_tkey);
 415
 416         if (k == NULL) {
 417                 return NT_STATUS_NO_MEMORY;
 418         }
 419
 420         k->name = talloc_strdup(k, name);
 421
 422         if (k->name  == NULL) {
 423                 return NT_STATUS_NO_MEMORY;
 424         }
 425
 426         k->algorithm = talloc_strdup(k, algorithm);
 427         if (k->algorithm == NULL) {
 428                 return NT_STATUS_NO_MEMORY;
 429         }
 430
 431         status = samba_server_gensec_start(k,
 432                                            dns->task->event_ctx,
 433                                            dns->task->msg_ctx,
 434                                            dns->task->lp_ctx,
 435                                            dns->server_credentials,
 436                                            "dns",
 437                                            &k->gensec);
 438         if (!NT_STATUS_IS_OK(status)) {
 439                 DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
 440                 *tkey = NULL;
 441                 return status;
 442         }
 443
 444         gensec_want_feature(k->gensec, GENSEC_FEATURE_SIGN);
 445
 446         status = gensec_start_mech_by_oid(k->gensec, GENSEC_OID_SPNEGO);
 447
 448         if (!NT_STATUS_IS_OK(status)) {
 449                 DEBUG(1, ("Failed to start GENSEC server code: %s\n",
 450                           nt_errstr(status)));
 451                 *tkey = NULL;
 452                 return status;
 453         }
 454
 455         if (store->tkeys[store->next_idx] != NULL) {
 456                 TALLOC_FREE(store->tkeys[store->next_idx]);
 457         }
 458
 459         store->tkeys[store->next_idx] = k;
 460         (store->next_idx)++;
 461         store->next_idx %= store->size;
 462
 463         *tkey = k;
 464         return NT_STATUS_OK;
 465 }
 466
 467 static NTSTATUS accept_gss_ticket(TALLOC_CTX *mem_ctx,
 468                                   struct dns_server *dns,
 469                                   struct dns_server_tkey *tkey,
 470                                   const DATA_BLOB *key,
 471                                   DATA_BLOB *reply,
 472                                   uint16_t *dns_auth_error)
 473 {
 474         NTSTATUS status;
 475
 476         status = gensec_update_ev(tkey->gensec, mem_ctx, dns->task->event_ctx,
 477                                   *key, reply);
 478
 479         if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
 480                 *dns_auth_error = DNS_RCODE_OK;
 481                 return status;
 482         }
 483
 484         if (NT_STATUS_IS_OK(status)) {
 485
 486                 status = gensec_session_info(tkey->gensec, tkey, &tkey->session_info);
 487                 if (!NT_STATUS_IS_OK(status)) {
 488                         *dns_auth_error = DNS_RCODE_BADKEY;
 489                         return status;
 490                 }
 491                 *dns_auth_error = DNS_RCODE_OK;
 492         }
 493
 494         return status;
 495 }
 496
 497 static WERROR handle_tkey(struct dns_server *dns,
 498                           TALLOC_CTX *mem_ctx,
 499                           const struct dns_name_packet *in,
 500                           struct dns_request_state *state,
 501                           struct dns_res_rec **answers,
 502                           uint16_t *ancount)
 503 {
 504         struct dns_res_rec *in_tkey = NULL;
 505         struct dns_res_rec *ret_tkey;
 506         uint16_t i;
 507
 508         for (i = 0; i < in->arcount; i++) {
 509                 if (in->additional[i].rr_type == DNS_QTYPE_TKEY) {
 510                         in_tkey = &in->additional[i];
 511                         break;
 512                 }
 513         }
 514
 515         /* If this is a TKEY query, it should have a TKEY RR.
 516          * Behaviour is not really specified in RFC 2930 or RFC 3645, but
 517          * FORMAT_ERROR seems to be what BIND uses .*/
 518         if (in_tkey == NULL) {
 519                 return DNS_ERR(FORMAT_ERROR);
 520         }
 521
 522         ret_tkey = talloc_zero(mem_ctx, struct dns_res_rec);
 523         if (ret_tkey == NULL) {
 524                 return WERR_NOMEM;
 525         }
 526
 527         ret_tkey->name = talloc_strdup(ret_tkey, in_tkey->name);
 528         if (ret_tkey->name == NULL) {
 529                 return WERR_NOMEM;
 530         }
 531
 532         ret_tkey->rr_type = DNS_QTYPE_TKEY;
 533         ret_tkey->rr_class = DNS_QCLASS_ANY;
 534         ret_tkey->length = UINT16_MAX;
 535
 536         ret_tkey->rdata.tkey_record.algorithm = talloc_strdup(ret_tkey,
 537                         in_tkey->rdata.tkey_record.algorithm);
 538         if (ret_tkey->rdata.tkey_record.algorithm  == NULL) {
 539                 return WERR_NOMEM;
 540         }
 541
 542         ret_tkey->rdata.tkey_record.inception = in_tkey->rdata.tkey_record.inception;
 543         ret_tkey->rdata.tkey_record.expiration = in_tkey->rdata.tkey_record.expiration;
 544         ret_tkey->rdata.tkey_record.mode = in_tkey->rdata.tkey_record.mode;
 545
 546         switch (in_tkey->rdata.tkey_record.mode) {
 547         case DNS_TKEY_MODE_DH:
 548                 /* FIXME: According to RFC 2930, we MUST support this, but we don't.
 549                  * Still, claim it's a bad key instead of a bad mode */
 550                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 551                 break;
 552         case DNS_TKEY_MODE_GSSAPI: {
 553                 NTSTATUS status;
 554                 struct dns_server_tkey *tkey;
 555                 DATA_BLOB key;
 556                 DATA_BLOB reply;
 557
 558                 tkey = dns_find_tkey(dns->tkeys, in->questions[0].name);
 559                 if (tkey != NULL && tkey->complete) {
 560                         /* TODO: check if the key is still valid */
 561                         DEBUG(1, ("Rejecting tkey negotiation for already established key\n"));
 562                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADNAME;
 563                         break;
 564                 }
 565
 566                 if (tkey == NULL) {
 567                         status  = create_tkey(dns, in->questions[0].name,
 568                                               in_tkey->rdata.tkey_record.algorithm,
 569                                               &tkey);
 570                         if (!NT_STATUS_IS_OK(status)) {
 571                                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 572                                 return ntstatus_to_werror(status);
 573                         }
 574                 }
 575
 576                 key.data = in_tkey->rdata.tkey_record.key_data;
 577                 key.length = in_tkey->rdata.tkey_record.key_size;
 578
 579                 status = accept_gss_ticket(ret_tkey, dns, tkey, &key, &reply,
 580                                            &ret_tkey->rdata.tkey_record.error);
 581                 if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 582                         DEBUG(1, ("More processing required\n"));
 583                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 584                 } else if (NT_STATUS_IS_OK(status)) {
 585                         DEBUG(1, ("Tkey handshake completed\n"));
 586                         ret_tkey->rdata.tkey_record.key_size = reply.length;
 587                         ret_tkey->rdata.tkey_record.key_data = talloc_memdup(ret_tkey,
 588                                                                 reply.data,
 589                                                                 reply.length);
 590                         state->sign = true;
 591                         state->key_name = talloc_strdup(state->mem_ctx, tkey->name);
 592                         if (state->key_name == NULL) {
 593                                 return WERR_NOMEM;
 594                         }
 595                 } else {
 596                         DEBUG(1, ("GSS key negotiation returned %s\n", nt_errstr(status)));
 597                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 598                 }
 599
 600                 break;
 601                 }
 602         case DNS_TKEY_MODE_DELETE:
 603                 /* TODO: implement me */
 604                 DEBUG(1, ("Should delete tkey here\n"));
 605                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_OK;
 606                 break;
 607         case DNS_TKEY_MODE_NULL:
 608         case DNS_TKEY_MODE_SERVER:
 609         case DNS_TKEY_MODE_CLIENT:
 610         case DNS_TKEY_MODE_LAST:
 611                 /* We don't have to implement these, return a mode error */
 612                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADMODE;
 613                 break;
 614         default:
 615                 DEBUG(1, ("Unsupported TKEY mode %d\n",
 616                       in_tkey->rdata.tkey_record.mode));
 617         }
 618
 619         *answers = ret_tkey;
 620         *ancount = 1;
 621
 622         return WERR_OK;
 623 }
 624
 625 struct dns_server_process_query_state {
 626         struct dns_res_rec *answers;
 627         uint16_t ancount;
 628         struct dns_res_rec *nsrecs;
 629         uint16_t nscount;
 630         struct dns_res_rec *additional;
 631         uint16_t arcount;
 632 };
 633
 634 static void dns_server_process_query_got_response(struct tevent_req *subreq);
 635
 636 struct tevent_req *dns_server_process_query_send(
 637         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 638         struct dns_server *dns, struct dns_request_state *req_state,
 639         const struct dns_name_packet *in)
 640 {
 641         struct tevent_req *req, *subreq;
 642         struct dns_server_process_query_state *state;
 643
 644         req = tevent_req_create(mem_ctx, &state,
 645                                 struct dns_server_process_query_state);
 646         if (req == NULL) {
 647                 return NULL;
 648         }
 649         if (in->qdcount != 1) {
 650                 tevent_req_werror(req, DNS_ERR(FORMAT_ERROR));
 651                 return tevent_req_post(req, ev);
 652         }
 653
 654         /* Windows returns NOT_IMPLEMENTED on this as well */
 655         if (in->questions[0].question_class == DNS_QCLASS_NONE) {
 656                 tevent_req_werror(req, DNS_ERR(NOT_IMPLEMENTED));
 657                 return tevent_req_post(req, ev);
 658         }
 659
 660         if (in->questions[0].question_type == DNS_QTYPE_TKEY) {
 661                 WERROR err;
 662
 663                 err = handle_tkey(dns, state, in, req_state,
 664                                   &state->answers, &state->ancount);
 665                 if (tevent_req_werror(req, err)) {
 666                         return tevent_req_post(req, ev);
 667                 }
 668                 tevent_req_done(req);
 669                 return tevent_req_post(req, ev);
 670         }
 671
 672         if (dns_authorative_for_zone(dns, in->questions[0].name)) {
 673                 WERROR err;
 674
 675                 req_state->flags |= DNS_FLAG_AUTHORITATIVE;
 676                 err = handle_question(dns, state, &in->questions[0],
 677                                       &state->answers, &state->ancount,
 678                                       &state->nsrecs, &state->nscount);
 679
 680                 if (W_ERROR_EQUAL(err, DNS_ERR(NAME_ERROR))) {
 681                         err = WERR_OK;
 682                 }
 683
 684                 if (tevent_req_werror(req, err)) {
 685                         return tevent_req_post(req, ev);
 686                 }
 687
 688                 tevent_req_done(req);
 689                 return tevent_req_post(req, ev);
 690         }
 691
 692         if ((req_state->flags & DNS_FLAG_RECURSION_DESIRED) &&
 693             (req_state->flags & DNS_FLAG_RECURSION_AVAIL)) {
 694                 DEBUG(2, ("Not authoritative for '%s', forwarding\n",
 695                           in->questions[0].name));
 696
 697                 subreq = ask_forwarder_send(
 698                         dns,
 699                         state, ev, lpcfg_dns_forwarder(dns->task->lp_ctx),
 700                         &in->questions[0]);
 701                 if (tevent_req_nomem(subreq, req)) {
 702                         return tevent_req_post(req, ev);
 703                 }
 704                 tevent_req_set_callback(
 705                         subreq, dns_server_process_query_got_response, req);
 706                 return req;
 707         }
 708
 709         tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 710         return tevent_req_post(req, ev);
 711 }
 712
 713 static void dns_server_process_query_got_response(struct tevent_req *subreq)
 714 {
 715         struct tevent_req *req = tevent_req_callback_data(
 716                 subreq, struct tevent_req);
 717         struct dns_server_process_query_state *state = tevent_req_data(
 718                 req, struct dns_server_process_query_state);
 719         WERROR err;
 720
 721         err = ask_forwarder_recv(subreq, state,
 722                                  &state->answers, &state->ancount,
 723                                  &state->nsrecs, &state->nscount,
 724                                  &state->additional, &state->arcount);
 725         TALLOC_FREE(subreq);
 726         if (tevent_req_werror(req, err)) {
 727                 return;
 728         }
 729         tevent_req_done(req);
 730 }
 731
 732 WERROR dns_server_process_query_recv(
 733         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 734         struct dns_res_rec **answers,    uint16_t *ancount,
 735         struct dns_res_rec **nsrecs,     uint16_t *nscount,
 736         struct dns_res_rec **additional, uint16_t *arcount)
 737 {
 738         struct dns_server_process_query_state *state = tevent_req_data(
 739                 req, struct dns_server_process_query_state);
 740         WERROR err = WERR_OK;
 741
 742         if (tevent_req_is_werror(req, &err)) {
 743
 744                 if ((!W_ERROR_EQUAL(err, DNS_ERR(NAME_ERROR))) &&
 745                     (!W_ERROR_EQUAL(err, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST))) {
 746                         return err;
 747                 }
 748         }
 749         *answers = talloc_move(mem_ctx, &state->answers);
 750         *ancount = state->ancount;
 751         *nsrecs = talloc_move(mem_ctx, &state->nsrecs);
 752         *nscount = state->nscount;
 753         *additional = talloc_move(mem_ctx, &state->additional);
 754         *arcount = state->arcount;
 755         return err;
 756 }