source4/dns_server/dns_server.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    DNS server startup
   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 "smbd/service.h"
  25 #include "smbd/service_stream.h"
  26 #include "smbd/process_model.h"
  27 #include "lib/events/events.h"
  28 #include "lib/socket/socket.h"
  29 #include "lib/tsocket/tsocket.h"
  30 #include "libcli/util/tstream.h"
  31 #include "libcli/util/ntstatus.h"
  32 #include "system/network.h"
  33 #include "lib/stream/packet.h"
  34 #include "lib/socket/netif.h"
  35 #include "dns_server/dns_server.h"
  36 #include "param/param.h"
  37 #include "librpc/ndr/libndr.h"
  38 #include "librpc/gen_ndr/ndr_dns.h"
  39 #include "librpc/gen_ndr/ndr_dnsp.h"
  40 #include <ldb.h>
  41 #include "dsdb/samdb/samdb.h"
  42 #include "dsdb/common/util.h"
  43 #include "auth/session.h"
  44 #include "lib/util/dlinklist.h"
  45
  46 /* hold information about one dns socket */
  47 struct dns_socket {
  48         struct dns_server *dns;
  49         struct tsocket_address *local_address;
  50 };
  51
  52 struct dns_udp_socket {
  53         struct dns_socket *dns_socket;
  54         struct tdgram_context *dgram;
  55         struct tevent_queue *send_queue;
  56 };
  57
  58 /*
  59   state of an open tcp connection
  60 */
  61 struct dns_tcp_connection {
  62         /* stream connection we belong to */
  63         struct stream_connection *conn;
  64
  65         /* the dns_server the connection belongs to */
  66         struct dns_socket *dns_socket;
  67
  68         struct tstream_context *tstream;
  69
  70         struct tevent_queue *send_queue;
  71 };
  72
  73 static void dns_tcp_terminate_connection(struct dns_tcp_connection *dnsconn, const char *reason)
  74 {
  75         stream_terminate_connection(dnsconn->conn, reason);
  76 }
  77
  78 static void dns_tcp_recv(struct stream_connection *conn, uint16_t flags)
  79 {
  80         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
  81                                                              struct dns_tcp_connection);
  82         /* this should never be triggered! */
  83         dns_tcp_terminate_connection(dnsconn, "dns_tcp_recv: called");
  84 }
  85
  86 static void dns_tcp_send(struct stream_connection *conn, uint16_t flags)
  87 {
  88         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
  89                                                              struct dns_tcp_connection);
  90         /* this should never be triggered! */
  91         dns_tcp_terminate_connection(dnsconn, "dns_tcp_send: called");
  92 }
  93
  94 static NTSTATUS dns_err_to_ntstatus(enum dns_rcode rcode)
  95 {
  96         switch (rcode) {
  97         case DNS_RCODE_OK: return NT_STATUS_OK;
  98         case DNS_RCODE_FORMERR: return NT_STATUS_INVALID_PARAMETER;
  99         case DNS_RCODE_SERVFAIL: return NT_STATUS_INTERNAL_ERROR;
 100         case DNS_RCODE_NXDOMAIN: return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 101         case DNS_RCODE_NOTIMP: return NT_STATUS_NOT_IMPLEMENTED;
 102         case DNS_RCODE_REFUSED: return NT_STATUS_ACCESS_DENIED;
 103         case DNS_RCODE_NOTAUTH: return NT_STATUS_FOOBAR;
 104         default: return NT_STATUS_NONE_MAPPED;
 105         }
 106 }
 107
 108 static uint8_t ntstatus_to_dns_err(NTSTATUS status)
 109 {
 110         if (NT_STATUS_EQUAL(NT_STATUS_OK, status)) {
 111                 return DNS_RCODE_OK;
 112         } else if (NT_STATUS_EQUAL(NT_STATUS_INVALID_PARAMETER, status)) {
 113                 return DNS_RCODE_FORMERR;
 114         } else if (NT_STATUS_EQUAL(NT_STATUS_INTERNAL_ERROR, status)) {
 115                 return DNS_RCODE_SERVFAIL;
 116         } else if (NT_STATUS_EQUAL(NT_STATUS_OBJECT_NAME_NOT_FOUND, status)) {
 117                 return DNS_RCODE_NXDOMAIN;
 118         } else if (NT_STATUS_EQUAL(NT_STATUS_NOT_IMPLEMENTED, status)) {
 119                 return DNS_RCODE_NOTIMP;
 120         } else if (NT_STATUS_EQUAL(NT_STATUS_ACCESS_DENIED, status)) {
 121                 return DNS_RCODE_REFUSED;
 122         } else if (NT_STATUS_EQUAL(NT_STATUS_FOOBAR, status)) {
 123                 return DNS_RCODE_NOTAUTH;
 124         }
 125         DEBUG(0, ("No mapping exists for %s\n", nt_errstr(status)));
 126 }
 127
 128 static bool dns_name_match(const char *zone, const char *name, size_t *host_part_len)
 129 {
 130         size_t zl = strlen(zone);
 131         size_t nl = strlen(name);
 132         ssize_t zi, ni;
 133         static const size_t fixup = 'a' - 'A';
 134
 135         if (zl > nl) {
 136                 return false;
 137         }
 138
 139         for (zi = zl, ni = nl; zi >= 0; zi--, ni--) {
 140                 char zc = zone[zi];
 141                 char nc = name[ni];
 142
 143                 /* convert to lower case */
 144                 if (zc >= 'A' && zc <= 'Z') {
 145                         zc += fixup;
 146                 }
 147                 if (nc >= 'A' && nc <= 'Z') {
 148                         nc += fixup;
 149                 }
 150
 151                 if (zc != nc) {
 152                         return false;
 153                 }
 154         }
 155
 156         if (ni >= 0) {
 157                 if (name[ni] != '.') {
 158                         return false;
 159                 }
 160
 161                 ni--;
 162         }
 163
 164         *host_part_len = ni+1;
 165
 166         return true;
 167 }
 168
 169 static NTSTATUS dns_name2dn(struct dns_server *dns,
 170                             TALLOC_CTX *mem_ctx,
 171                             const char *name,
 172                             struct ldb_dn **_dn)
 173 {
 174         struct ldb_dn *base;
 175         struct ldb_dn *dn;
 176         const struct dns_server_zone *z;
 177         size_t host_part_len = 0;
 178
 179         if (name == NULL) {
 180                 return NT_STATUS_INVALID_PARAMETER;
 181         }
 182
 183         /*TODO: Check if 'name' is a valid DNS name */
 184
 185         if (strcmp(name, "") == 0) {
 186                 base = ldb_get_default_basedn(dns->samdb);
 187                 dn = ldb_dn_copy(mem_ctx, base);
 188                 ldb_dn_add_child_fmt(dn, "DC=@,DC=RootDNSServers,CN=MicrosoftDNS,CN=System");
 189                 *_dn = dn;
 190                 return NT_STATUS_OK;
 191         }
 192
 193         for (z = dns->zones; z != NULL; z = z->next) {
 194                 bool match;
 195
 196                 match = dns_name_match(z->name, name, &host_part_len);
 197                 if (match) {
 198                         break;
 199                 }
 200         }
 201
 202         if (z == NULL) {
 203                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 204         }
 205
 206         if (host_part_len == 0) {
 207                 dn = ldb_dn_copy(mem_ctx, z->dn);
 208                 ldb_dn_add_child_fmt(dn, "DC=@");
 209                 *_dn = dn;
 210                 return NT_STATUS_OK;
 211         }
 212
 213         dn = ldb_dn_copy(mem_ctx, z->dn);
 214         ldb_dn_add_child_fmt(dn, "DC=%*.*s", (int)host_part_len, (int)host_part_len, name);
 215         *_dn = dn;
 216         return NT_STATUS_OK;
 217 }
 218
 219 static NTSTATUS handle_question(struct dns_server *dns,
 220                                 TALLOC_CTX *mem_ctx,
 221                                 const struct dns_name_question *question,
 222                                 struct dns_res_rec **answers, uint16_t *ancount)
 223 {
 224         struct dns_res_rec *ans;
 225         struct ldb_dn *dn = NULL;
 226         NTSTATUS status;
 227         static const char * const attrs[] = { "dnsRecord", NULL};
 228         int ret;
 229         uint16_t ai = *ancount;
 230         uint16_t ri;
 231         struct ldb_message *msg = NULL;
 232         struct dnsp_DnssrvRpcRecord *recs;
 233         struct ldb_message_element *el;
 234
 235         status = dns_name2dn(dns, mem_ctx, question->name, &dn);
 236         NT_STATUS_NOT_OK_RETURN(status);
 237
 238         ret = dsdb_search_one(dns->samdb, mem_ctx, &msg, dn,
 239                               LDB_SCOPE_BASE, attrs, 0, "%s", "(objectClass=dnsNode)");
 240         if (ret != LDB_SUCCESS) {
 241                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 242         }
 243
 244         el = ldb_msg_find_element(msg, attrs[0]);
 245         if (el == NULL) {
 246                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 247         }
 248
 249         recs = talloc_array(mem_ctx, struct dnsp_DnssrvRpcRecord, el->num_values);
 250         for (ri = 0; ri < el->num_values; ri++) {
 251                 struct ldb_val *v = &el->values[ri];
 252                 enum ndr_err_code ndr_err;
 253
 254                 ndr_err = ndr_pull_struct_blob(v, recs, &recs[ri],
 255                                 (ndr_pull_flags_fn_t)ndr_pull_dnsp_DnssrvRpcRecord);
 256                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 257                         DEBUG(0, ("Failed to grab dnsp_DnssrvRpcRecord\n"));
 258                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 259                 }
 260         }
 261
 262         ans = talloc_realloc(mem_ctx, *answers, struct dns_res_rec,
 263                              ai + el->num_values);
 264         NT_STATUS_HAVE_NO_MEMORY(ans);
 265
 266         switch (question->question_type) {
 267         case DNS_QTYPE_CNAME:
 268                 for (ri = 0; ri < el->num_values; ri++) {
 269                         if (recs[ri].wType != question->question_type) {
 270                                 continue;
 271                         }
 272
 273                         ZERO_STRUCT(ans[ai]);
 274                         ans[ai].name = talloc_strdup(ans, question->name);
 275                         ans[ai].rr_type = DNS_QTYPE_CNAME;
 276                         ans[ai].rr_class = DNS_QCLASS_IP;
 277                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 278                         ans[ai].length = UINT16_MAX;
 279                         ans[ai].rdata.cname_record = talloc_strdup(ans, recs[ri].data.cname);
 280                         ai++;
 281                 }
 282                 break;
 283         case DNS_QTYPE_A:
 284                 for (ri = 0; ri < el->num_values; ri++) {
 285                         if (recs[ri].wType != question->question_type) {
 286                                 continue;
 287                         }
 288
 289                         /* TODO: if the record actually is a DNS_QTYPE_A */
 290
 291                         ZERO_STRUCT(ans[ai]);
 292                         ans[ai].name = talloc_strdup(ans, question->name);
 293                         ans[ai].rr_type = DNS_QTYPE_A;
 294                         ans[ai].rr_class = DNS_QCLASS_IP;
 295                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 296                         ans[ai].length = UINT16_MAX;
 297                         ans[ai].rdata.ipv4_record = talloc_strdup(ans, recs[ri].data.ipv4);
 298                         ai++;
 299                 }
 300                 break;
 301         case DNS_QTYPE_AAAA:
 302                 for (ri = 0; ri < el->num_values; ri++) {
 303                         if (recs[ri].wType != question->question_type) {
 304                                 continue;
 305                         }
 306
 307                         ZERO_STRUCT(ans[ai]);
 308                         ans[ai].name = talloc_strdup(ans, question->name);
 309                         ans[ai].rr_type = DNS_QTYPE_AAAA;
 310                         ans[ai].rr_class = DNS_QCLASS_IP;
 311                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 312                         ans[ai].length = UINT16_MAX;
 313                         ans[ai].rdata.ipv6_record = recs[ri].data.ipv6;
 314                         ai++;
 315                 }
 316                 break;
 317         case DNS_QTYPE_NS:
 318                 for (ri = 0; ri < el->num_values; ri++) {
 319                         if (recs[ri].wType != question->question_type) {
 320                                 continue;
 321                         }
 322
 323                         ZERO_STRUCT(ans[ai]);
 324                         ans[ai].name = question->name;
 325                         ans[ai].rr_type = DNS_QTYPE_NS;
 326                         ans[ai].rr_class = DNS_QCLASS_IP;
 327                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 328                         ans[ai].length = UINT16_MAX;
 329                         ans[ai].rdata.ns_record = recs[ri].data.ns;
 330                         ai++;
 331                 }
 332                 break;
 333         case DNS_QTYPE_SRV:
 334                 for (ri = 0; ri < el->num_values; ri++) {
 335                         if (recs[ri].wType != question->question_type) {
 336                                 continue;
 337                         }
 338
 339                         ZERO_STRUCT(ans[ai]);
 340                         ans[ai].name = question->name;
 341                         ans[ai].rr_type = DNS_QTYPE_SRV;
 342                         ans[ai].rr_class = DNS_QCLASS_IP;
 343                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 344                         ans[ai].length = UINT16_MAX;
 345                         ans[ai].rdata.srv_record.priority = recs[ri].data.srv.wPriority;
 346                         ans[ai].rdata.srv_record.weight = recs[ri].data.srv.wWeight;
 347                         ans[ai].rdata.srv_record.port = recs[ri].data.srv.wPort;
 348                         ans[ai].rdata.srv_record.target = recs[ri].data.srv.nameTarget;
 349                         ai++;
 350                 }
 351                 break;
 352         case DNS_QTYPE_SOA:
 353                 for (ri = 0; ri < el->num_values; ri++) {
 354                         if (recs[ri].wType != question->question_type) {
 355                                 continue;
 356                         }
 357
 358                         ZERO_STRUCT(ans[ai]);
 359                         ans[ai].name = question->name;
 360                         ans[ai].rr_type = DNS_QTYPE_SOA;
 361                         ans[ai].rr_class = DNS_QCLASS_IP;
 362                         ans[ai].ttl = recs[ri].dwTtlSeconds;
 363                         ans[ai].length = UINT16_MAX;
 364                         ans[ai].rdata.soa_record.mname  = recs[ri].data.soa.mname;
 365                         ans[ai].rdata.soa_record.rname  = recs[ri].data.soa.rname;
 366                         ans[ai].rdata.soa_record.serial = recs[ri].data.soa.serial;
 367                         ans[ai].rdata.soa_record.refresh= recs[ri].data.soa.refresh;
 368                         ans[ai].rdata.soa_record.retry  = recs[ri].data.soa.retry;
 369                         ans[ai].rdata.soa_record.expire = recs[ri].data.soa.expire;
 370                         ans[ai].rdata.soa_record.minimum= recs[ri].data.soa.minimum;
 371                         ai++;
 372                 }
 373                 break;
 374         default:
 375                 return NT_STATUS_NOT_IMPLEMENTED;
 376         }
 377
 378         if (*ancount == ai) {
 379                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 380         }
 381
 382         *ancount = ai;
 383         *answers = ans;
 384
 385         return NT_STATUS_OK;
 386
 387 }
 388
 389 static NTSTATUS dns_server_process_query(struct dns_server *dns,
 390                                          TALLOC_CTX *mem_ctx,
 391                                          struct dns_name_packet *in,
 392                                          struct dns_res_rec **answers,    uint16_t *ancount,
 393                                          struct dns_res_rec **nsrecs,     uint16_t *nscount,
 394                                          struct dns_res_rec **additional, uint16_t *arcount)
 395 {
 396         uint16_t num_answers=0;
 397         struct dns_res_rec *ans=NULL;
 398         int i;
 399         NTSTATUS status;
 400
 401         ans = talloc_array(mem_ctx, struct dns_res_rec, 0);
 402         if (answers == NULL) return NT_STATUS_NO_MEMORY;
 403
 404         for (i = 0; i < in->qdcount; ++i) {
 405                 status = handle_question(dns, mem_ctx, &in->questions[i], &ans, &num_answers);
 406                 NT_STATUS_NOT_OK_RETURN(status);
 407         }
 408
 409         *answers = ans;
 410         *ancount = num_answers;
 411
 412         /*FIXME: Do something for these */
 413         *nsrecs  = NULL;
 414         *nscount = 0;
 415
 416         *additional = NULL;
 417         *arcount    = 0;
 418
 419         return NT_STATUS_OK;
 420 }
 421
 422 static NTSTATUS dns_server_process_update(struct dns_server *dns,
 423                                           TALLOC_CTX *mem_ctx,
 424                                           struct dns_name_packet *in,
 425                                           struct dns_res_rec **prereqs,    uint16_t *prereq_count,
 426                                           struct dns_res_rec **updates,    uint16_t *update_count,
 427                                           struct dns_res_rec **additional, uint16_t *arcount)
 428 {
 429         struct dns_name_question *zone;
 430         const struct dns_server_zone *z;
 431         size_t host_part_len = 0;
 432
 433         if (in->qdcount != 1) {
 434                 return NT_STATUS_INVALID_PARAMETER;
 435         }
 436
 437         zone = in->questions;
 438
 439         if (zone->question_type != DNS_QTYPE_SOA) {
 440                 return NT_STATUS_INVALID_PARAMETER;
 441         }
 442
 443         DEBUG(0, ("Got a dns update request.\n"));
 444
 445         for (z = dns->zones; z != NULL; z = z->next) {
 446                 bool match;
 447
 448                 match = dns_name_match(z->name, zone->name, &host_part_len);
 449                 if (match) {
 450                         break;
 451                 }
 452         }
 453
 454         if (z == NULL) {
 455                 return NT_STATUS_FOOBAR;
 456         }
 457
 458         if (host_part_len != 0) {
 459                 return NT_STATUS_NOT_IMPLEMENTED;
 460         }
 461
 462         return NT_STATUS_NOT_IMPLEMENTED;
 463 }
 464
 465 static NTSTATUS dns_process(struct dns_server *dns,
 466                             TALLOC_CTX *mem_ctx,
 467                             DATA_BLOB *in,
 468                             DATA_BLOB *out)
 469 {
 470         enum ndr_err_code ndr_err;
 471         NTSTATUS ret;
 472         struct dns_name_packet *in_packet;
 473         struct dns_name_packet *out_packet;
 474         struct dns_res_rec *answers = NULL, *nsrecs = NULL, *additional = NULL;
 475         uint16_t num_answers = 0 , num_nsrecs = 0, num_additional = 0;
 476         uint16_t reply_code;
 477
 478         if (in->length < 12) {
 479                 return NT_STATUS_INVALID_PARAMETER;
 480         }
 481
 482         in_packet = talloc_zero(mem_ctx, struct dns_name_packet);
 483         /* TODO: We don't really need an out_packet. */
 484         out_packet = talloc_zero(mem_ctx, struct dns_name_packet);
 485
 486         if (in_packet == NULL) return NT_STATUS_NO_MEMORY;
 487         if (out_packet == NULL) return NT_STATUS_NO_MEMORY;
 488
 489         dump_data(2, in->data, in->length);
 490
 491         ndr_err = ndr_pull_struct_blob(in, in_packet, in_packet,
 492                         (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
 493         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 494                 TALLOC_FREE(in_packet);
 495                 DEBUG(0, ("Failed to parse packet %d!\n", ndr_err));
 496                 *out = *in;
 497
 498                 out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
 499                 out->data[3] |= DNS_RCODE_FORMERR;
 500
 501                 return NT_STATUS_OK;
 502         }
 503
 504         NDR_PRINT_DEBUG(dns_name_packet, in_packet);
 505         *out_packet = *in_packet;
 506         out_packet->operation |= DNS_FLAG_REPLY;
 507
 508         switch (in_packet->operation & DNS_OPCODE) {
 509         case DNS_OPCODE_QUERY:
 510
 511                 ret = dns_server_process_query(dns, out_packet, in_packet,
 512                                                &answers, &num_answers,
 513                                                &nsrecs,  &num_nsrecs,
 514                                                &additional, &num_additional);
 515                 reply_code = DNS_RCODE_NXDOMAIN;
 516
 517                 break;
 518         case DNS_OPCODE_REGISTER:
 519                 ret = dns_server_process_update(dns, out_packet, in_packet,
 520                                                 &answers, &num_answers,
 521                                                 &nsrecs,  &num_nsrecs,
 522                                                 &additional, &num_additional);
 523                 reply_code = ntstatus_to_dns_err(ret);
 524                 break;
 525         default:
 526                 ret = NT_STATUS_NOT_IMPLEMENTED;
 527                 reply_code = DNS_RCODE_NOTIMP;
 528                 break;
 529         }
 530
 531         if (NT_STATUS_IS_OK(ret)) {
 532                 out_packet->ancount = num_answers;
 533                 out_packet->answers = answers;
 534
 535                 out_packet->nscount = num_nsrecs;
 536                 out_packet->nsrecs  = nsrecs;
 537
 538                 out_packet->arcount = num_additional;
 539                 out_packet->additional = additional;
 540         } else {
 541                 out_packet->operation |= reply_code;
 542         }
 543
 544         NDR_PRINT_DEBUG(dns_name_packet, out_packet);
 545         ndr_err = ndr_push_struct_blob(out, out_packet, out_packet,
 546                         (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
 547         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 548                 TALLOC_FREE(in_packet);
 549                 TALLOC_FREE(out_packet);
 550                 DEBUG(0, ("Failed to push packet %d!\n", ndr_err));
 551                 *out = *in;
 552
 553                 out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
 554                 out->data[3] |= DNS_RCODE_SERVFAIL;
 555
 556                 return NT_STATUS_OK;
 557         }
 558
 559         dump_data(2, out->data, out->length);
 560         return NT_STATUS_OK;
 561 }
 562
 563 struct dns_tcp_call {
 564         struct dns_tcp_connection *dns_conn;
 565         DATA_BLOB in;
 566         DATA_BLOB out;
 567         uint8_t out_hdr[4];
 568         struct iovec out_iov[2];
 569 };
 570
 571 static void dns_tcp_call_writev_done(struct tevent_req *subreq);
 572
 573 static void dns_tcp_call_loop(struct tevent_req *subreq)
 574 {
 575         struct dns_tcp_connection *dns_conn = tevent_req_callback_data(subreq,
 576                                       struct dns_tcp_connection);
 577         struct dns_tcp_call *call;
 578         NTSTATUS status;
 579
 580         call = talloc(dns_conn, struct dns_tcp_call);
 581         if (call == NULL) {
 582                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 583                                 "no memory for dns_tcp_call");
 584                 return;
 585         }
 586         call->dns_conn = dns_conn;
 587
 588         status = tstream_read_pdu_blob_recv(subreq,
 589                                             call,
 590                                             &call->in);
 591         TALLOC_FREE(subreq);
 592         if (!NT_STATUS_IS_OK(status)) {
 593                 const char *reason;
 594
 595                 reason = talloc_asprintf(call, "dns_tcp_call_loop: "
 596                                          "tstream_read_pdu_blob_recv() - %s",
 597                                          nt_errstr(status));
 598                 if (!reason) {
 599                         reason = nt_errstr(status);
 600                 }
 601
 602                 dns_tcp_terminate_connection(dns_conn, reason);
 603                 return;
 604         }
 605
 606         DEBUG(10,("Received krb5 TCP packet of length %lu from %s\n",
 607                  (long) call->in.length,
 608                  tsocket_address_string(dns_conn->conn->remote_address, call)));
 609
 610         /* skip length header */
 611         call->in.data +=4;
 612         call->in.length -= 4;
 613
 614         /* Call dns */
 615         status = dns_process(dns_conn->dns_socket->dns, call, &call->in, &call->out);
 616         if (!NT_STATUS_IS_OK(status)) {
 617                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 618                 dns_tcp_terminate_connection(dns_conn,
 619                                 "dns_tcp_call_loop: process function failed");
 620                 return;
 621         }
 622
 623         /* First add the length of the out buffer */
 624         RSIVAL(call->out_hdr, 0, call->out.length);
 625         call->out_iov[0].iov_base = (char *) call->out_hdr;
 626         call->out_iov[0].iov_len = 4;
 627
 628         call->out_iov[1].iov_base = (char *) call->out.data;
 629         call->out_iov[1].iov_len = call->out.length;
 630
 631         subreq = tstream_writev_queue_send(call,
 632                                            dns_conn->conn->event.ctx,
 633                                            dns_conn->tstream,
 634                                            dns_conn->send_queue,
 635                                            call->out_iov, 2);
 636         if (subreq == NULL) {
 637                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 638                                 "no memory for tstream_writev_queue_send");
 639                 return;
 640         }
 641         tevent_req_set_callback(subreq, dns_tcp_call_writev_done, call);
 642
 643         /*
 644          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 645          * packet_full_request_u32 provides the pdu length then.
 646          */
 647         subreq = tstream_read_pdu_blob_send(dns_conn,
 648                                             dns_conn->conn->event.ctx,
 649                                             dns_conn->tstream,
 650                                             4, /* initial_read_size */
 651                                             packet_full_request_u32,
 652                                             dns_conn);
 653         if (subreq == NULL) {
 654                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
 655                                 "no memory for tstream_read_pdu_blob_send");
 656                 return;
 657         }
 658         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 659 }
 660
 661 static void dns_tcp_call_writev_done(struct tevent_req *subreq)
 662 {
 663         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
 664                         struct dns_tcp_call);
 665         int sys_errno;
 666         int rc;
 667
 668         rc = tstream_writev_queue_recv(subreq, &sys_errno);
 669         TALLOC_FREE(subreq);
 670         if (rc == -1) {
 671                 const char *reason;
 672
 673                 reason = talloc_asprintf(call, "dns_tcp_call_writev_done: "
 674                                          "tstream_writev_queue_recv() - %d:%s",
 675                                          sys_errno, strerror(sys_errno));
 676                 if (!reason) {
 677                         reason = "dns_tcp_call_writev_done: tstream_writev_queue_recv() failed";
 678                 }
 679
 680                 dns_tcp_terminate_connection(call->dns_conn, reason);
 681                 return;
 682         }
 683
 684         /* We don't care about errors */
 685
 686         talloc_free(call);
 687 }
 688
 689 /*
 690   called when we get a new connection
 691 */
 692 static void dns_tcp_accept(struct stream_connection *conn)
 693 {
 694         struct dns_socket *dns_socket;
 695         struct dns_tcp_connection *dns_conn;
 696         struct tevent_req *subreq;
 697         int rc;
 698
 699         dns_conn = talloc_zero(conn, struct dns_tcp_connection);
 700         if (dns_conn == NULL) {
 701                 stream_terminate_connection(conn,
 702                                 "dns_tcp_accept: out of memory");
 703                 return;
 704         }
 705
 706         dns_conn->send_queue = tevent_queue_create(conn, "dns_tcp_accept");
 707         if (dns_conn->send_queue == NULL) {
 708                 stream_terminate_connection(conn,
 709                                 "dns_tcp_accept: out of memory");
 710                 return;
 711         }
 712
 713         dns_socket = talloc_get_type(conn->private_data, struct dns_socket);
 714
 715         TALLOC_FREE(conn->event.fde);
 716
 717         rc = tstream_bsd_existing_socket(dns_conn,
 718                         socket_get_fd(conn->socket),
 719                         &dns_conn->tstream);
 720         if (rc < 0) {
 721                 stream_terminate_connection(conn,
 722                                 "dns_tcp_accept: out of memory");
 723                 return;
 724         }
 725
 726         dns_conn->conn = conn;
 727         dns_conn->dns_socket = dns_socket;
 728         conn->private_data = dns_conn;
 729
 730         /*
 731          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 732          * packet_full_request_u32 provides the pdu length then.
 733          */
 734         subreq = tstream_read_pdu_blob_send(dns_conn,
 735                                             dns_conn->conn->event.ctx,
 736                                             dns_conn->tstream,
 737                                             4, /* initial_read_size */
 738                                             packet_full_request_u32,
 739                                             dns_conn);
 740         if (subreq == NULL) {
 741                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_accept: "
 742                                 "no memory for tstream_read_pdu_blob_send");
 743                 return;
 744         }
 745         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
 746 }
 747
 748 static const struct stream_server_ops dns_tcp_stream_ops = {
 749         .name                   = "dns_tcp",
 750         .accept_connection      = dns_tcp_accept,
 751         .recv_handler           = dns_tcp_recv,
 752         .send_handler           = dns_tcp_send
 753 };
 754
 755 struct dns_udp_call {
 756         struct tsocket_address *src;
 757         DATA_BLOB in;
 758         DATA_BLOB out;
 759 };
 760
 761 static void dns_udp_call_sendto_done(struct tevent_req *subreq);
 762
 763 static void dns_udp_call_loop(struct tevent_req *subreq)
 764 {
 765         struct dns_udp_socket *sock = tevent_req_callback_data(subreq,
 766                                       struct dns_udp_socket);
 767         struct dns_udp_call *call;
 768         uint8_t *buf;
 769         ssize_t len;
 770         int sys_errno;
 771         NTSTATUS status;
 772
 773         call = talloc(sock, struct dns_udp_call);
 774         if (call == NULL) {
 775                 talloc_free(call);
 776                 goto done;
 777         }
 778
 779         len = tdgram_recvfrom_recv(subreq, &sys_errno,
 780                                    call, &buf, &call->src);
 781         TALLOC_FREE(subreq);
 782         if (len == -1) {
 783                 talloc_free(call);
 784                 goto done;
 785         }
 786
 787         call->in.data = buf;
 788         call->in.length = len;
 789
 790         DEBUG(10,("Received krb5 UDP packet of length %lu from %s\n",
 791                  (long)call->in.length,
 792                  tsocket_address_string(call->src, call)));
 793
 794         /* Call krb5 */
 795         status = dns_process(sock->dns_socket->dns, call, &call->in, &call->out);
 796         if (!NT_STATUS_IS_OK(status)) {
 797                 talloc_free(call);
 798                 DEBUG(0, ("dns_process returned %s\n", nt_errstr(status)));
 799                 goto done;
 800         }
 801
 802         subreq = tdgram_sendto_queue_send(call,
 803                                           sock->dns_socket->dns->task->event_ctx,
 804                                           sock->dgram,
 805                                           sock->send_queue,
 806                                           call->out.data,
 807                                           call->out.length,
 808                                           call->src);
 809         if (subreq == NULL) {
 810                 talloc_free(call);
 811                 goto done;
 812         }
 813         tevent_req_set_callback(subreq, dns_udp_call_sendto_done, call);
 814
 815 done:
 816         subreq = tdgram_recvfrom_send(sock,
 817                                       sock->dns_socket->dns->task->event_ctx,
 818                                       sock->dgram);
 819         if (subreq == NULL) {
 820                 task_server_terminate(sock->dns_socket->dns->task,
 821                                       "no memory for tdgram_recvfrom_send",
 822                                       true);
 823                 return;
 824         }
 825         tevent_req_set_callback(subreq, dns_udp_call_loop, sock);
 826 }
 827
 828 static void dns_udp_call_sendto_done(struct tevent_req *subreq)
 829 {
 830         struct dns_udp_call *call = tevent_req_callback_data(subreq,
 831                                        struct dns_udp_call);
 832         ssize_t ret;
 833         int sys_errno;
 834
 835         ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
 836
 837         /* We don't care about errors */
 838
 839         talloc_free(call);
 840 }
 841
 842 /*
 843   start listening on the given address
 844 */
 845 static NTSTATUS dns_add_socket(struct dns_server *dns,
 846                                const struct model_ops *model_ops,
 847                                const char *name,
 848                                const char *address,
 849                                uint16_t port)
 850 {
 851         struct dns_socket *dns_socket;
 852         struct dns_udp_socket *dns_udp_socket;
 853         struct tevent_req *udpsubreq;
 854         NTSTATUS status;
 855         int ret;
 856
 857         dns_socket = talloc(dns, struct dns_socket);
 858         NT_STATUS_HAVE_NO_MEMORY(dns_socket);
 859
 860         dns_socket->dns = dns;
 861
 862         ret = tsocket_address_inet_from_strings(dns_socket, "ip",
 863                                                 address, port,
 864                                                 &dns_socket->local_address);
 865         if (ret != 0) {
 866                 status = map_nt_error_from_unix(errno);
 867                 return status;
 868         }
 869
 870         status = stream_setup_socket(dns->task->event_ctx,
 871                                      dns->task->lp_ctx,
 872                                      model_ops,
 873                                      &dns_tcp_stream_ops,
 874                                      "ip", address, &port,
 875                                      lpcfg_socket_options(dns->task->lp_ctx),
 876                                      dns_socket);
 877         if (!NT_STATUS_IS_OK(status)) {
 878                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 879                          address, port, nt_errstr(status)));
 880                 talloc_free(dns_socket);
 881                 return status;
 882         }
 883
 884         dns_udp_socket = talloc(dns_socket, struct dns_udp_socket);
 885         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket);
 886
 887         dns_udp_socket->dns_socket = dns_socket;
 888
 889         ret = tdgram_inet_udp_socket(dns_socket->local_address,
 890                                      NULL,
 891                                      dns_udp_socket,
 892                                      &dns_udp_socket->dgram);
 893         if (ret != 0) {
 894                 status = map_nt_error_from_unix(errno);
 895                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
 896                          address, port, nt_errstr(status)));
 897                 return status;
 898         }
 899
 900         dns_udp_socket->send_queue = tevent_queue_create(dns_udp_socket,
 901                                                          "dns_udp_send_queue");
 902         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket->send_queue);
 903
 904         udpsubreq = tdgram_recvfrom_send(dns_udp_socket,
 905                                          dns->task->event_ctx,
 906                                          dns_udp_socket->dgram);
 907         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
 908         tevent_req_set_callback(udpsubreq, dns_udp_call_loop, dns_udp_socket);
 909
 910         return NT_STATUS_OK;
 911 }
 912
 913 /*
 914   setup our listening sockets on the configured network interfaces
 915 */
 916 static NTSTATUS dns_startup_interfaces(struct dns_server *dns, struct loadparm_context *lp_ctx,
 917                                        struct interface *ifaces)
 918 {
 919         const struct model_ops *model_ops;
 920         int num_interfaces;
 921         TALLOC_CTX *tmp_ctx = talloc_new(dns);
 922         NTSTATUS status;
 923         int i;
 924
 925         /* within the dns task we want to be a single process, so
 926            ask for the single process model ops and pass these to the
 927            stream_setup_socket() call. */
 928         model_ops = process_model_startup(dns->task->event_ctx, "single");
 929         if (!model_ops) {
 930                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 931                 return NT_STATUS_INTERNAL_ERROR;
 932         }
 933
 934         num_interfaces = iface_count(ifaces);
 935
 936         for (i=0; i<num_interfaces; i++) {
 937                 const char *address = talloc_strdup(tmp_ctx, iface_n_ip(ifaces, i));
 938
 939                 status = dns_add_socket(dns, model_ops, "dns", address, DNS_SERVICE_PORT);
 940                 NT_STATUS_NOT_OK_RETURN(status);
 941         }
 942
 943         talloc_free(tmp_ctx);
 944
 945         return NT_STATUS_OK;
 946 }
 947
 948 static int dns_server_sort_zones(struct ldb_message **m1, struct ldb_message **m2)
 949 {
 950         const char *n1, *n2;
 951         size_t l1, l2;
 952
 953         n1 = ldb_msg_find_attr_as_string(*m1, "name", NULL);
 954         n2 = ldb_msg_find_attr_as_string(*m2, "name", NULL);
 955
 956         l1 = strlen(n1);
 957         l2 = strlen(n2);
 958
 959         /* If the string lengths are not equal just sort by length */
 960         if (l1 != l2) {
 961                 /* If m1 is the larger zone name, return it first */
 962                 return l2 - l1;
 963         }
 964
 965         /*TODO: We need to compare DNs here, we want the DomainDNSZones first */
 966         return 0;
 967 }
 968
 969 static void dns_task_init(struct task_server *task)
 970 {
 971         struct dns_server *dns;
 972         NTSTATUS status;
 973         struct interface *ifaces;
 974         int ret;
 975         struct ldb_result *res;
 976         struct ldb_dn *rootdn;
 977         static const char * const attrs[] = { "name", NULL};
 978         int i;
 979
 980
 981         switch (lpcfg_server_role(task->lp_ctx)) {
 982         case ROLE_STANDALONE:
 983                 task_server_terminate(task, "dns: no DNS required in standalone configuration", false);
 984                 return;
 985         case ROLE_DOMAIN_MEMBER:
 986                 task_server_terminate(task, "dns: no DNS required in member server configuration", false);
 987                 return;
 988         case ROLE_DOMAIN_CONTROLLER:
 989                 /* Yes, we want a DNS */
 990                 break;
 991         }
 992
 993         load_interfaces(task, lpcfg_interfaces(task->lp_ctx), &ifaces);
 994
 995         if (iface_count(ifaces) == 0) {
 996                 task_server_terminate(task, "dns: no network interfaces configured", false);
 997                 return;
 998         }
 999
1000         task_server_set_title(task, "task[dns]");
1001
1002         dns = talloc_zero(task, struct dns_server);
1003         if (dns == NULL) {
1004                 task_server_terminate(task, "dns: out of memory", true);
1005                 return;
1006         }
1007
1008         dns->task = task;
1009
1010         dns->samdb = samdb_connect(dns, dns->task->event_ctx, dns->task->lp_ctx,
1011                               system_session(dns->task->lp_ctx), 0);
1012         if (!dns->samdb) {
1013                 task_server_terminate(task, "dns: samdb_connect failed", true);
1014                 return;
1015         }
1016
1017         rootdn = ldb_dn_new(dns, dns->samdb, "");
1018         if (rootdn == NULL) {
1019                 task_server_terminate(task, "dns: out of memory", true);
1020                 return;
1021         }
1022
1023         // TODO: this search does not work against windows
1024         ret = dsdb_search(dns->samdb, dns, &res, rootdn, LDB_SCOPE_SUBTREE,
1025                           attrs, DSDB_SEARCH_SEARCH_ALL_PARTITIONS, "(objectClass=dnsZone)");
1026         if (ret != LDB_SUCCESS) {
1027                 task_server_terminate(task,
1028                                       "dns: failed to look up root DNS zones",
1029                                       true);
1030                 return;
1031         }
1032
1033         TYPESAFE_QSORT(res->msgs, res->count, dns_server_sort_zones);
1034
1035         for (i=0; i < res->count; i++) {
1036                 struct dns_server_zone *z;
1037
1038                 z = talloc_zero(dns, struct dns_server_zone);
1039                 if (z == NULL) {
1040                 }
1041
1042                 z->name = ldb_msg_find_attr_as_string(res->msgs[i], "name", NULL);
1043                 z->dn = talloc_move(z, &res->msgs[i]->dn);
1044
1045                 DLIST_ADD_END(dns->zones, z, NULL);
1046         }
1047
1048         status = dns_startup_interfaces(dns, task->lp_ctx, ifaces);
1049         if (!NT_STATUS_IS_OK(status)) {
1050                 task_server_terminate(task, "dns failed to setup interfaces", true);
1051                 return;
1052         }
1053 }
1054
1055 NTSTATUS server_service_dns_init(void)
1056 {
1057         return register_server_service("dns", dns_task_init);
1058 }