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, werror_return;
 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         /* Set up for an NXDOMAIN reply if no match is found */
 279         werror_return = DNS_ERR(NAME_ERROR);
 280
 281         for (ri = 0; ri < rec_count; ri++) {
 282                 if ((recs[ri].wType == DNS_TYPE_CNAME) &&
 283                     ((question->question_type == DNS_QTYPE_A) ||
 284                      (question->question_type == DNS_QTYPE_AAAA))) {
 285                         struct dns_name_question *new_q =
 286                                 talloc(mem_ctx, struct dns_name_question);
 287
 288                         if (new_q == NULL) {
 289                                 return WERR_NOMEM;
 290                         }
 291
 292                         /* We reply with one more record, so grow the array */
 293                         ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec,
 294                                              rec_count + 1);
 295                         if (ans == NULL) {
 296                                 TALLOC_FREE(new_q);
 297                                 return WERR_NOMEM;
 298                         }
 299
 300                         /* First put in the CNAME record */
 301                         werror = create_response_rr(question, &recs[ri], &ans, &ai);
 302                         if (!W_ERROR_IS_OK(werror)) {
 303                                 return werror;
 304                         }
 305
 306                         /* And then look up the name it points at.. */
 307
 308                         /* First build up the new question */
 309                         new_q->question_type = question->question_type;
 310                         new_q->question_class = question->question_class;
 311                         if (new_q->question_type == DNS_QTYPE_A) {
 312                                 new_q->name = talloc_strdup(new_q, recs[ri].data.ipv4);
 313                         } else if (new_q->question_type == DNS_QTYPE_AAAA) {
 314                                 new_q->name = talloc_strdup(new_q, recs[ri].data.ipv6);
 315                         }
 316                         if (new_q->name == NULL) {
 317                                 TALLOC_FREE(new_q);
 318                                 return WERR_NOMEM;
 319                         }
 320                         /* and then call the lookup again */
 321                         werror = handle_question(dns, mem_ctx, new_q, &ans, &ai);
 322                         if (!W_ERROR_IS_OK(werror)) {
 323                                 return werror;
 324                         }
 325                         werror_return = WERR_OK;
 326
 327
 328                         continue;
 329                 }
 330                 if ((question->question_type != DNS_QTYPE_ALL) &&
 331                     (recs[ri].wType != question->question_type)) {
 332                         werror_return = WERR_OK;
 333                         continue;
 334                 }
 335                 werror = create_response_rr(question, &recs[ri], &ans, &ai);
 336                 if (!W_ERROR_IS_OK(werror)) {
 337                         return werror;
 338                 }
 339                 werror_return = WERR_OK;
 340         }
 341
 342         *ancount = ai;
 343         *answers = ans;
 344
 345         return werror_return;
 346 }
 347
 348 static NTSTATUS create_tkey(struct dns_server *dns,
 349                             const char* name,
 350                             const char* algorithm,
 351                             struct dns_server_tkey **tkey)
 352 {
 353         NTSTATUS status;
 354         struct dns_server_tkey_store *store = dns->tkeys;
 355         struct dns_server_tkey *k = talloc_zero(store, struct dns_server_tkey);
 356
 357         if (k == NULL) {
 358                 return NT_STATUS_NO_MEMORY;
 359         }
 360
 361         k->name = talloc_strdup(k, name);
 362
 363         if (k->name  == NULL) {
 364                 return NT_STATUS_NO_MEMORY;
 365         }
 366
 367         k->algorithm = talloc_strdup(k, algorithm);
 368         if (k->algorithm == NULL) {
 369                 return NT_STATUS_NO_MEMORY;
 370         }
 371
 372         status = samba_server_gensec_start(k,
 373                                            dns->task->event_ctx,
 374                                            dns->task->msg_ctx,
 375                                            dns->task->lp_ctx,
 376                                            dns->server_credentials,
 377                                            "dns",
 378                                            &k->gensec);
 379         if (!NT_STATUS_IS_OK(status)) {
 380                 DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
 381                 *tkey = NULL;
 382                 return status;
 383         }
 384
 385         gensec_want_feature(k->gensec, GENSEC_FEATURE_SIGN);
 386
 387         status = gensec_start_mech_by_oid(k->gensec, GENSEC_OID_SPNEGO);
 388
 389         if (!NT_STATUS_IS_OK(status)) {
 390                 DEBUG(1, ("Failed to start GENSEC server code: %s\n",
 391                           nt_errstr(status)));
 392                 *tkey = NULL;
 393                 return status;
 394         }
 395
 396         if (store->tkeys[store->next_idx] != NULL) {
 397                 TALLOC_FREE(store->tkeys[store->next_idx]);
 398         }
 399
 400         store->tkeys[store->next_idx] = k;
 401         (store->next_idx)++;
 402         store->next_idx %= store->size;
 403
 404         *tkey = k;
 405         return NT_STATUS_OK;
 406 }
 407
 408 static NTSTATUS accept_gss_ticket(TALLOC_CTX *mem_ctx,
 409                                   struct dns_server *dns,
 410                                   struct dns_server_tkey *tkey,
 411                                   const DATA_BLOB *key,
 412                                   DATA_BLOB *reply,
 413                                   uint16_t *dns_auth_error)
 414 {
 415         NTSTATUS status;
 416
 417         status = gensec_update(tkey->gensec, mem_ctx, dns->task->event_ctx,
 418                                *key, reply);
 419
 420         if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
 421                 *dns_auth_error = DNS_RCODE_OK;
 422                 return status;
 423         }
 424
 425         if (NT_STATUS_IS_OK(status)) {
 426
 427                 status = gensec_session_info(tkey->gensec, tkey, &tkey->session_info);
 428                 if (!NT_STATUS_IS_OK(status)) {
 429                         *dns_auth_error = DNS_RCODE_BADKEY;
 430                         return status;
 431                 }
 432                 *dns_auth_error = DNS_RCODE_OK;
 433         }
 434
 435         return status;
 436 }
 437
 438 static WERROR handle_tkey(struct dns_server *dns,
 439                           TALLOC_CTX *mem_ctx,
 440                           const struct dns_name_packet *in,
 441                           struct dns_request_state *state,
 442                           struct dns_res_rec **answers,
 443                           uint16_t *ancount)
 444 {
 445         struct dns_res_rec *in_tkey = NULL;
 446         struct dns_res_rec *ret_tkey;
 447         uint16_t i;
 448
 449         for (i = 0; i < in->arcount; i++) {
 450                 if (in->additional[i].rr_type == DNS_QTYPE_TKEY) {
 451                         in_tkey = &in->additional[i];
 452                         break;
 453                 }
 454         }
 455
 456         /* If this is a TKEY query, it should have a TKEY RR.
 457          * Behaviour is not really specified in RFC 2930 or RFC 3645, but
 458          * FORMAT_ERROR seems to be what BIND uses .*/
 459         if (in_tkey == NULL) {
 460                 return DNS_ERR(FORMAT_ERROR);
 461         }
 462
 463         ret_tkey = talloc_zero(mem_ctx, struct dns_res_rec);
 464         if (ret_tkey == NULL) {
 465                 return WERR_NOMEM;
 466         }
 467
 468         ret_tkey->name = talloc_strdup(ret_tkey, in_tkey->name);
 469         if (ret_tkey->name == NULL) {
 470                 return WERR_NOMEM;
 471         }
 472
 473         ret_tkey->rr_type = DNS_QTYPE_TKEY;
 474         ret_tkey->rr_class = DNS_QCLASS_ANY;
 475         ret_tkey->length = UINT16_MAX;
 476
 477         ret_tkey->rdata.tkey_record.algorithm = talloc_strdup(ret_tkey,
 478                         in_tkey->rdata.tkey_record.algorithm);
 479         if (ret_tkey->rdata.tkey_record.algorithm  == NULL) {
 480                 return WERR_NOMEM;
 481         }
 482
 483         ret_tkey->rdata.tkey_record.inception = in_tkey->rdata.tkey_record.inception;
 484         ret_tkey->rdata.tkey_record.expiration = in_tkey->rdata.tkey_record.expiration;
 485         ret_tkey->rdata.tkey_record.mode = in_tkey->rdata.tkey_record.mode;
 486
 487         switch (in_tkey->rdata.tkey_record.mode) {
 488         case DNS_TKEY_MODE_DH:
 489                 /* FIXME: According to RFC 2930, we MUST support this, but we don't.
 490                  * Still, claim it's a bad key instead of a bad mode */
 491                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 492                 break;
 493         case DNS_TKEY_MODE_GSSAPI: {
 494                 NTSTATUS status;
 495                 struct dns_server_tkey *tkey;
 496                 DATA_BLOB key;
 497                 DATA_BLOB reply;
 498
 499                 tkey = dns_find_tkey(dns->tkeys, in->questions[0].name);
 500                 if (tkey != NULL && tkey->complete) {
 501                         /* TODO: check if the key is still valid */
 502                         DEBUG(1, ("Rejecting tkey negotiation for already established key\n"));
 503                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADNAME;
 504                         break;
 505                 }
 506
 507                 if (tkey == NULL) {
 508                         status  = create_tkey(dns, in->questions[0].name,
 509                                               in_tkey->rdata.tkey_record.algorithm,
 510                                               &tkey);
 511                         if (!NT_STATUS_IS_OK(status)) {
 512                                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 513                                 return ntstatus_to_werror(status);
 514                         }
 515                 }
 516
 517                 key.data = in_tkey->rdata.tkey_record.key_data;
 518                 key.length = in_tkey->rdata.tkey_record.key_size;
 519
 520                 status = accept_gss_ticket(ret_tkey, dns, tkey, &key, &reply,
 521                                            &ret_tkey->rdata.tkey_record.error);
 522                 if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 523                         DEBUG(1, ("More processing required\n"));
 524                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 525                 } else if (NT_STATUS_IS_OK(status)) {
 526                         DEBUG(1, ("Tkey handshake completed\n"));
 527                         ret_tkey->rdata.tkey_record.key_size = reply.length;
 528                         ret_tkey->rdata.tkey_record.key_data = talloc_memdup(ret_tkey,
 529                                                                 reply.data,
 530                                                                 reply.length);
 531                         state->sign = true;
 532                         state->key_name = talloc_strdup(mem_ctx, tkey->name);
 533                         if (state->key_name == NULL) {
 534                                 return WERR_NOMEM;
 535                         }
 536                 } else {
 537                         DEBUG(1, ("GSS key negotiation returned %s\n", nt_errstr(status)));
 538                         ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
 539                 }
 540
 541                 break;
 542                 }
 543         case DNS_TKEY_MODE_DELETE:
 544                 /* TODO: implement me */
 545                 DEBUG(1, ("Should delete tkey here\n"));
 546                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_OK;
 547                 break;
 548         case DNS_TKEY_MODE_NULL:
 549         case DNS_TKEY_MODE_SERVER:
 550         case DNS_TKEY_MODE_CLIENT:
 551         case DNS_TKEY_MODE_LAST:
 552                 /* We don't have to implement these, return a mode error */
 553                 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADMODE;
 554                 break;
 555         default:
 556                 DEBUG(1, ("Unsupported TKEY mode %d\n",
 557                       in_tkey->rdata.tkey_record.mode));
 558         }
 559
 560         *answers = ret_tkey;
 561         *ancount = 1;
 562
 563         return WERR_OK;
 564 }
 565
 566 struct dns_server_process_query_state {
 567         struct dns_res_rec *answers;
 568         uint16_t ancount;
 569         struct dns_res_rec *nsrecs;
 570         uint16_t nscount;
 571         struct dns_res_rec *additional;
 572         uint16_t arcount;
 573 };
 574
 575 static void dns_server_process_query_got_response(struct tevent_req *subreq);
 576
 577 struct tevent_req *dns_server_process_query_send(
 578         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 579         struct dns_server *dns, struct dns_request_state *req_state,
 580         const struct dns_name_packet *in)
 581 {
 582         struct tevent_req *req, *subreq;
 583         struct dns_server_process_query_state *state;
 584
 585         req = tevent_req_create(mem_ctx, &state,
 586                                 struct dns_server_process_query_state);
 587         if (req == NULL) {
 588                 return NULL;
 589         }
 590         if (in->qdcount != 1) {
 591                 tevent_req_werror(req, DNS_ERR(FORMAT_ERROR));
 592                 return tevent_req_post(req, ev);
 593         }
 594
 595         /* Windows returns NOT_IMPLEMENTED on this as well */
 596         if (in->questions[0].question_class == DNS_QCLASS_NONE) {
 597                 tevent_req_werror(req, DNS_ERR(NOT_IMPLEMENTED));
 598                 return tevent_req_post(req, ev);
 599         }
 600
 601         if (in->questions[0].question_type == DNS_QTYPE_TKEY) {
 602                 WERROR err;
 603
 604                 err = handle_tkey(dns, state, in, req_state,
 605                                   &state->answers, &state->ancount);
 606                 if (tevent_req_werror(req, err)) {
 607                         return tevent_req_post(req, ev);
 608                 }
 609                 tevent_req_done(req);
 610                 return tevent_req_post(req, ev);
 611         }
 612
 613         if (dns_authorative_for_zone(dns, in->questions[0].name)) {
 614                 WERROR err;
 615
 616                 req_state->flags |= DNS_FLAG_AUTHORITATIVE;
 617                 err = handle_question(dns, state, &in->questions[0],
 618                                       &state->answers, &state->ancount);
 619                 if (tevent_req_werror(req, err)) {
 620                         return tevent_req_post(req, ev);
 621                 }
 622                 tevent_req_done(req);
 623                 return tevent_req_post(req, ev);
 624         }
 625
 626         if ((req_state->flags & DNS_FLAG_RECURSION_DESIRED) &&
 627             (req_state->flags & DNS_FLAG_RECURSION_AVAIL)) {
 628                 DEBUG(2, ("Not authoritative for '%s', forwarding\n",
 629                           in->questions[0].name));
 630
 631                 subreq = ask_forwarder_send(
 632                         dns,
 633                         state, ev, lpcfg_dns_forwarder(dns->task->lp_ctx),
 634                         &in->questions[0]);
 635                 if (tevent_req_nomem(subreq, req)) {
 636                         return tevent_req_post(req, ev);
 637                 }
 638                 tevent_req_set_callback(
 639                         subreq, dns_server_process_query_got_response, req);
 640                 return req;
 641         }
 642
 643         tevent_req_werror(req, DNS_ERR(NAME_ERROR));
 644         return tevent_req_post(req, ev);
 645 }
 646
 647 static void dns_server_process_query_got_response(struct tevent_req *subreq)
 648 {
 649         struct tevent_req *req = tevent_req_callback_data(
 650                 subreq, struct tevent_req);
 651         struct dns_server_process_query_state *state = tevent_req_data(
 652                 req, struct dns_server_process_query_state);
 653         WERROR err;
 654
 655         err = ask_forwarder_recv(subreq, state,
 656                                  &state->answers, &state->ancount,
 657                                  &state->nsrecs, &state->nscount,
 658                                  &state->additional, &state->arcount);
 659         TALLOC_FREE(subreq);
 660         if (tevent_req_werror(req, err)) {
 661                 return;
 662         }
 663         tevent_req_done(req);
 664 }
 665
 666 WERROR dns_server_process_query_recv(
 667         struct tevent_req *req, TALLOC_CTX *mem_ctx,
 668         struct dns_res_rec **answers,    uint16_t *ancount,
 669         struct dns_res_rec **nsrecs,     uint16_t *nscount,
 670         struct dns_res_rec **additional, uint16_t *arcount)
 671 {
 672         struct dns_server_process_query_state *state = tevent_req_data(
 673                 req, struct dns_server_process_query_state);
 674         WERROR err;
 675
 676         if (tevent_req_is_werror(req, &err)) {
 677                 return err;
 678         }
 679         *answers = talloc_move(mem_ctx, &state->answers);
 680         *ancount = state->ancount;
 681         *nsrecs = talloc_move(mem_ctx, &state->nsrecs);
 682         *nscount = state->nscount;
 683         *additional = talloc_move(mem_ctx, &state->additional);
 684         *arcount = state->arcount;
 685         return WERR_OK;
 686 }