source/ldap_server/ldap_server.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    LDAP server
   5
   6    Copyright (C) Andrew Tridgell 2005
   7    Copyright (C) Volker Lendecke 2004
   8    Copyright (C) Stefan Metzmacher 2004
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "lib/events/events.h"
  26 #include "auth/auth.h"
  27 #include "auth/credentials/credentials.h"
  28 #include "librpc/gen_ndr/ndr_samr.h"
  29 #include "lib/util/dlinklist.h"
  30 #include "libcli/util/asn_1.h"
  31 #include "ldap_server/ldap_server.h"
  32 #include "smbd/service_task.h"
  33 #include "smbd/service_stream.h"
  34 #include "smbd/service.h"
  35 #include "smbd/process_model.h"
  36 #include "lib/tls/tls.h"
  37 #include "lib/messaging/irpc.h"
  38 #include "lib/ldb/include/ldb.h"
  39 #include "lib/ldb/include/ldb_errors.h"
  40 #include "system/network.h"
  41 #include "lib/socket/netif.h"
  42 #include "dsdb/samdb/samdb.h"
  43 #include "param/param.h"
  44 /*
  45   close the socket and shutdown a server_context
  46 */
  47 void ldapsrv_terminate_connection(struct ldapsrv_connection *conn,
  48                                          const char *reason)
  49 {
  50         stream_terminate_connection(conn->connection, reason);
  51 }
  52
  53 /*
  54   handle packet errors
  55 */
  56 static void ldapsrv_error_handler(void *private, NTSTATUS status)
  57 {
  58         struct ldapsrv_connection *conn = talloc_get_type(private,
  59                                                           struct ldapsrv_connection);
  60         ldapsrv_terminate_connection(conn, nt_errstr(status));
  61 }
  62
  63 /*
  64   process a decoded ldap message
  65 */
  66 static void ldapsrv_process_message(struct ldapsrv_connection *conn,
  67                                     struct ldap_message *msg)
  68 {
  69         struct ldapsrv_call *call;
  70         NTSTATUS status;
  71         DATA_BLOB blob;
  72
  73         call = talloc(conn, struct ldapsrv_call);
  74         if (!call) {
  75                 ldapsrv_terminate_connection(conn, "no memory");
  76                 return;
  77         }
  78
  79         call->request = talloc_steal(call, msg);
  80         call->conn = conn;
  81         call->replies = NULL;
  82         call->send_callback = NULL;
  83         call->send_private = NULL;
  84
  85         /* make the call */
  86         status = ldapsrv_do_call(call);
  87         if (!NT_STATUS_IS_OK(status)) {
  88                 talloc_free(call);
  89                 return;
  90         }
  91
  92         blob = data_blob(NULL, 0);
  93
  94         if (call->replies == NULL) {
  95                 talloc_free(call);
  96                 return;
  97         }
  98
  99         /* build all the replies into a single blob */
 100         while (call->replies) {
 101                 DATA_BLOB b;
 102                 bool ret;
 103
 104                 msg = call->replies->msg;
 105                 if (!ldap_encode(msg, &b, call)) {
 106                         DEBUG(0,("Failed to encode ldap reply of type %d\n", msg->type));
 107                         talloc_free(call);
 108                         return;
 109                 }
 110
 111                 ret = data_blob_append(call, &blob, b.data, b.length);
 112                 data_blob_free(&b);
 113
 114                 talloc_set_name_const(blob.data, "Outgoing, encoded LDAP packet");
 115
 116                 if (!ret) {
 117                         talloc_free(call);
 118                         return;
 119                 }
 120
 121                 DLIST_REMOVE(call->replies, call->replies);
 122         }
 123
 124         packet_send_callback(conn->packet, blob,
 125                              call->send_callback, call->send_private);
 126         talloc_free(call);
 127         return;
 128 }
 129
 130 /*
 131   decode/process data
 132 */
 133 static NTSTATUS ldapsrv_decode(void *private, DATA_BLOB blob)
 134 {
 135         NTSTATUS status;
 136         struct ldapsrv_connection *conn = talloc_get_type(private,
 137                                                           struct ldapsrv_connection);
 138         struct asn1_data *asn1 = asn1_init(conn);
 139         struct ldap_message *msg = talloc(conn, struct ldap_message);
 140
 141         if (asn1 == NULL || msg == NULL) {
 142                 return NT_STATUS_NO_MEMORY;
 143         }
 144
 145         if (!asn1_load(asn1, blob)) {
 146                 talloc_free(msg);
 147                 talloc_free(asn1);
 148                 return NT_STATUS_NO_MEMORY;
 149         }
 150
 151         status = ldap_decode(asn1, msg);
 152         if (!NT_STATUS_IS_OK(status)) {
 153                 asn1_free(asn1);
 154                 return status;
 155         }
 156
 157         data_blob_free(&blob);
 158         ldapsrv_process_message(conn, msg);
 159         asn1_free(asn1);
 160         return NT_STATUS_OK;
 161 }
 162
 163 /*
 164  Idle timeout handler
 165 */
 166 static void ldapsrv_conn_idle_timeout(struct event_context *ev,
 167                                       struct timed_event *te,
 168                                       struct timeval t,
 169                                       void *private)
 170 {
 171         struct ldapsrv_connection *conn = talloc_get_type(private, struct ldapsrv_connection);
 172
 173         ldapsrv_terminate_connection(conn, "Timeout. No requests after bind");
 174 }
 175
 176 /*
 177   called when a LDAP socket becomes readable
 178 */
 179 void ldapsrv_recv(struct stream_connection *c, uint16_t flags)
 180 {
 181         struct ldapsrv_connection *conn =
 182                 talloc_get_type(c->private, struct ldapsrv_connection);
 183
 184         if (conn->limits.ite) { /* clean initial timeout if any */
 185                 talloc_free(conn->limits.ite);
 186                 conn->limits.ite = NULL;
 187         }
 188
 189         if (conn->limits.te) { /* clean idle timeout if any */
 190                 talloc_free(conn->limits.te);
 191                 conn->limits.te = NULL;
 192         }
 193
 194         packet_recv(conn->packet);
 195
 196         /* set idle timeout */
 197         conn->limits.te = event_add_timed(c->event.ctx, conn,
 198                                            timeval_current_ofs(conn->limits.conn_idle_time, 0),
 199                                            ldapsrv_conn_idle_timeout, conn);
 200 }
 201
 202 /*
 203   called when a LDAP socket becomes writable
 204 */
 205 static void ldapsrv_send(struct stream_connection *c, uint16_t flags)
 206 {
 207         struct ldapsrv_connection *conn =
 208                 talloc_get_type(c->private, struct ldapsrv_connection);
 209
 210         packet_queue_run(conn->packet);
 211 }
 212
 213 static void ldapsrv_conn_init_timeout(struct event_context *ev,
 214                                       struct timed_event *te,
 215                                       struct timeval t,
 216                                       void *private)
 217 {
 218         struct ldapsrv_connection *conn = talloc_get_type(private, struct ldapsrv_connection);
 219
 220         ldapsrv_terminate_connection(conn, "Timeout. No requests after initial connection");
 221 }
 222
 223 static int ldapsrv_load_limits(struct ldapsrv_connection *conn)
 224 {
 225         TALLOC_CTX *tmp_ctx;
 226         const char *attrs[] = { "configurationNamingContext", NULL };
 227         const char *attrs2[] = { "lDAPAdminLimits", NULL };
 228         struct ldb_message_element *el;
 229         struct ldb_result *res = NULL;
 230         struct ldb_dn *basedn;
 231         struct ldb_dn *conf_dn;
 232         struct ldb_dn *policy_dn;
 233         int i,ret;
 234
 235         /* set defaults limits in case of failure */
 236         conn->limits.initial_timeout = 120;
 237         conn->limits.conn_idle_time = 900;
 238         conn->limits.max_page_size = 1000;
 239         conn->limits.search_timeout = 120;
 240
 241
 242         tmp_ctx = talloc_new(conn);
 243         if (tmp_ctx == NULL) {
 244                 return -1;
 245         }
 246
 247         basedn = ldb_dn_new(tmp_ctx, conn->ldb, NULL);
 248         if ( ! ldb_dn_validate(basedn)) {
 249                 goto failed;
 250         }
 251
 252         ret = ldb_search(conn->ldb, basedn, LDB_SCOPE_BASE, NULL, attrs, &res);
 253         if (ret != LDB_SUCCESS) {
 254                 goto failed;
 255         }
 256
 257         talloc_steal(tmp_ctx, res);
 258
 259         if (res->count != 1) {
 260                 goto failed;
 261         }
 262
 263         conf_dn = ldb_msg_find_attr_as_dn(conn->ldb, tmp_ctx, res->msgs[0], "configurationNamingContext");
 264         if (conf_dn == NULL) {
 265                 goto failed;
 266         }
 267
 268         policy_dn = ldb_dn_copy(tmp_ctx, conf_dn);
 269         ldb_dn_add_child_fmt(policy_dn, "CN=Default Query Policy,CN=Query-Policies,CN=Directory Service,CN=Windows NT,CN=Services");
 270         if (policy_dn == NULL) {
 271                 goto failed;
 272         }
 273
 274         ret = ldb_search(conn->ldb, policy_dn, LDB_SCOPE_BASE, NULL, attrs2, &res);
 275         if (ret != LDB_SUCCESS) {
 276                 goto failed;
 277         }
 278
 279         talloc_steal(tmp_ctx, res);
 280
 281         if (res->count != 1) {
 282                 goto failed;
 283         }
 284
 285         el = ldb_msg_find_element(res->msgs[0], "lDAPAdminLimits");
 286         if (el == NULL) {
 287                 goto failed;
 288         }
 289
 290         for (i = 0; i < el->num_values; i++) {
 291                 char policy_name[256];
 292                 int policy_value, s;
 293
 294                 s = sscanf((const char *)el->values[i].data, "%255[^=]=%d", policy_name, &policy_value);
 295                 if (ret != 2 || policy_value == 0)
 296                         continue;
 297
 298                 if (strcasecmp("InitRecvTimeout", policy_name) == 0) {
 299                         conn->limits.initial_timeout = policy_value;
 300                         continue;
 301                 }
 302                 if (strcasecmp("MaxConnIdleTime", policy_name) == 0) {
 303                         conn->limits.conn_idle_time = policy_value;
 304                         continue;
 305                 }
 306                 if (strcasecmp("MaxPageSize", policy_name) == 0) {
 307                         conn->limits.max_page_size = policy_value;
 308                         continue;
 309                 }
 310                 if (strcasecmp("MaxQueryDuration", policy_name) == 0) {
 311                         conn->limits.search_timeout = policy_value;
 312                         continue;
 313                 }
 314         }
 315
 316         return 0;
 317
 318 failed:
 319         DEBUG(0, ("Failed to load ldap server query policies\n"));
 320         talloc_free(tmp_ctx);
 321         return -1;
 322 }
 323
 324 /*
 325   initialise a server_context from a open socket and register a event handler
 326   for reading from that socket
 327 */
 328 static void ldapsrv_accept(struct stream_connection *c)
 329 {
 330         struct ldapsrv_service *ldapsrv_service =
 331                 talloc_get_type(c->private, struct ldapsrv_service);
 332         struct ldapsrv_connection *conn;
 333         struct cli_credentials *server_credentials;
 334         struct socket_address *socket_address;
 335         NTSTATUS status;
 336         int port;
 337
 338         conn = talloc_zero(c, struct ldapsrv_connection);
 339         if (!conn) {
 340                 stream_terminate_connection(c, "ldapsrv_accept: out of memory");
 341                 return;
 342         }
 343
 344         conn->packet      = NULL;
 345         conn->connection  = c;
 346         conn->service     = ldapsrv_service;
 347         conn->sockets.raw = c->socket;
 348
 349         c->private        = conn;
 350
 351         socket_address = socket_get_my_addr(c->socket, conn);
 352         if (!socket_address) {
 353                 ldapsrv_terminate_connection(conn, "ldapsrv_accept: failed to obtain local socket address!");
 354                 return;
 355         }
 356         port = socket_address->port;
 357         talloc_free(socket_address);
 358
 359         if (port == 636) {
 360                 struct socket_context *tls_socket = tls_init_server(ldapsrv_service->tls_params, c->socket,
 361                                                                     c->event.fde, NULL);
 362                 if (!tls_socket) {
 363                         ldapsrv_terminate_connection(conn, "ldapsrv_accept: tls_init_server() failed");
 364                         return;
 365                 }
 366                 talloc_unlink(c, c->socket);
 367                 talloc_steal(c, tls_socket);
 368                 c->socket = tls_socket;
 369                 conn->sockets.tls = tls_socket;
 370
 371         } else if (port == 3268) /* Global catalog */ {
 372                 conn->global_catalog = True;
 373         }
 374         conn->packet = packet_init(conn);
 375         if (conn->packet == NULL) {
 376                 ldapsrv_terminate_connection(conn, "out of memory");
 377                 return;
 378         }
 379
 380         packet_set_private(conn->packet, conn);
 381         packet_set_socket(conn->packet, c->socket);
 382         packet_set_callback(conn->packet, ldapsrv_decode);
 383         packet_set_full_request(conn->packet, ldap_full_packet);
 384         packet_set_error_handler(conn->packet, ldapsrv_error_handler);
 385         packet_set_event_context(conn->packet, c->event.ctx);
 386         packet_set_fde(conn->packet, c->event.fde);
 387         packet_set_serialise(conn->packet);
 388
 389         /* Ensure we don't get packets until the database is ready below */
 390         packet_recv_disable(conn->packet);
 391
 392         server_credentials
 393                 = cli_credentials_init(conn);
 394         if (!server_credentials) {
 395                 stream_terminate_connection(c, "Failed to init server credentials\n");
 396                 return;
 397         }
 398
 399         cli_credentials_set_conf(server_credentials);
 400         status = cli_credentials_set_machine_account(server_credentials);
 401         if (!NT_STATUS_IS_OK(status)) {
 402                 stream_terminate_connection(c, talloc_asprintf(conn, "Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(status)));
 403                 return;
 404         }
 405         conn->server_credentials = server_credentials;
 406
 407         /* Connections start out anonymous */
 408         if (!NT_STATUS_IS_OK(auth_anonymous_session_info(conn, &conn->session_info))) {
 409                 ldapsrv_terminate_connection(conn, "failed to setup anonymous session info");
 410                 return;
 411         }
 412
 413         if (!NT_STATUS_IS_OK(ldapsrv_backend_Init(conn))) {
 414                 ldapsrv_terminate_connection(conn, "backend Init failed");
 415                 return;
 416         }
 417
 418         /* load limits from the conf partition */
 419         ldapsrv_load_limits(conn); /* should we fail on error ? */
 420
 421         /* register the server */
 422         irpc_add_name(c->msg_ctx, "ldap_server");
 423
 424         /* set connections limits */
 425         conn->limits.ite = event_add_timed(c->event.ctx, conn,
 426                                            timeval_current_ofs(conn->limits.initial_timeout, 0),
 427                                            ldapsrv_conn_init_timeout, conn);
 428
 429         packet_recv_enable(conn->packet);
 430
 431 }
 432
 433 static const struct stream_server_ops ldap_stream_ops = {
 434         .name                   = "ldap",
 435         .accept_connection      = ldapsrv_accept,
 436         .recv_handler           = ldapsrv_recv,
 437         .send_handler           = ldapsrv_send,
 438 };
 439
 440 /*
 441   add a socket address to the list of events, one event per port
 442 */
 443 static NTSTATUS add_socket(struct event_context *event_context,
 444                            const struct model_ops *model_ops,
 445                            const char *address, struct ldapsrv_service *ldap_service)
 446 {
 447         uint16_t port = 389;
 448         NTSTATUS status;
 449         const char *attrs[] = { "options", NULL };
 450         int ret;
 451         struct ldb_result *res;
 452         struct ldb_context *ldb;
 453         int options;
 454
 455         status = stream_setup_socket(event_context, model_ops, &ldap_stream_ops,
 456                                      "ipv4", address, &port, ldap_service);
 457         if (!NT_STATUS_IS_OK(status)) {
 458                 DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
 459                          address, port, nt_errstr(status)));
 460         }
 461
 462         if (tls_support(ldap_service->tls_params)) {
 463                 /* add ldaps server */
 464                 port = 636;
 465                 status = stream_setup_socket(event_context, model_ops, &ldap_stream_ops,
 466                                              "ipv4", address, &port, ldap_service);
 467                 if (!NT_STATUS_IS_OK(status)) {
 468                         DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
 469                                  address, port, nt_errstr(status)));
 470                 }
 471         }
 472
 473         /* Load LDAP database */
 474         ldb = samdb_connect(ldap_service, system_session(ldap_service));
 475         if (!ldb) {
 476                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 477         }
 478
 479         /* Query cn=ntds settings,.... */
 480         ret = ldb_search(ldb, samdb_ntds_settings_dn(ldb), LDB_SCOPE_BASE, NULL, attrs, &res);
 481         if (ret) {
 482                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 483         }
 484         if (res->count != 1) {
 485                 talloc_free(res);
 486                 return NT_STATUS_NOT_FOUND;
 487         }
 488
 489         options = ldb_msg_find_attr_as_int(res->msgs[0], "options", 0);
 490         talloc_free(res);
 491         talloc_free(ldb);
 492
 493         /* if options attribute has the 0x00000001 flag set, then enable the global catlog */
 494         if (options & 0x000000001) {
 495                 port = 3268;
 496                 status = stream_setup_socket(event_context, model_ops, &ldap_stream_ops,
 497                                              "ipv4", address, &port, ldap_service);
 498                 if (!NT_STATUS_IS_OK(status)) {
 499                         DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
 500                                  address, port, nt_errstr(status)));
 501                 }
 502         }
 503
 504         return status;
 505 }
 506
 507 /*
 508   open the ldap server sockets
 509 */
 510 static void ldapsrv_task_init(struct task_server *task)
 511 {
 512         struct ldapsrv_service *ldap_service;
 513         NTSTATUS status;
 514         const struct model_ops *model_ops;
 515
 516         switch (lp_server_role()) {
 517         case ROLE_STANDALONE:
 518                 task_server_terminate(task, "ldap_server: no LDAP server required in standalone configuration");
 519                 return;
 520         case ROLE_DOMAIN_MEMBER:
 521                 task_server_terminate(task, "ldap_server: no LDAP server required in member server configuration");
 522                 return;
 523         case ROLE_DOMAIN_CONTROLLER:
 524                 /* Yes, we want an LDAP server */
 525                 break;
 526         }
 527
 528         task_server_set_title(task, "task[ldapsrv]");
 529
 530         /* run the ldap server as a single process */
 531         model_ops = process_model_byname("single");
 532         if (!model_ops) goto failed;
 533
 534         ldap_service = talloc_zero(task, struct ldapsrv_service);
 535         if (ldap_service == NULL) goto failed;
 536
 537         ldap_service->tls_params = tls_initialise(ldap_service);
 538         if (ldap_service->tls_params == NULL) goto failed;
 539
 540         if (lp_interfaces() && lp_bind_interfaces_only()) {
 541                 int num_interfaces = iface_count();
 542                 int i;
 543
 544                 /* We have been given an interfaces line, and been
 545                    told to only bind to those interfaces. Create a
 546                    socket per interface and bind to only these.
 547                 */
 548                 for(i = 0; i < num_interfaces; i++) {
 549                         const char *address = iface_n_ip(i);
 550                         status = add_socket(task->event_ctx, model_ops, address, ldap_service);
 551                         if (!NT_STATUS_IS_OK(status)) goto failed;
 552                 }
 553         } else {
 554                 status = add_socket(task->event_ctx, model_ops,
 555                                     lp_socket_address(), ldap_service);
 556                 if (!NT_STATUS_IS_OK(status)) goto failed;
 557         }
 558
 559         return;
 560
 561 failed:
 562         task_server_terminate(task, "Failed to startup ldap server task");
 563 }
 564
 565 /*
 566   called on startup of the web server service It's job is to start
 567   listening on all configured sockets
 568 */
 569 static NTSTATUS ldapsrv_init(struct event_context *event_context,
 570                              const struct model_ops *model_ops)
 571 {
 572         return task_server_startup(event_context, model_ops, ldapsrv_task_init);
 573 }
 574
 575
 576 NTSTATUS server_service_ldap_init(void)
 577 {
 578         return register_server_service("ldap", ldapsrv_init);
 579 }