source4/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 2 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, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 #include "includes.h"
  26 #include "lib/events/events.h"
  27 #include "auth/auth.h"
  28 #include "auth/credentials/credentials.h"
  29 #include "librpc/gen_ndr/ndr_samr.h"
  30 #include "lib/util/dlinklist.h"
  31 #include "libcli/util/asn_1.h"
  32 #include "ldap_server/ldap_server.h"
  33 #include "smbd/service_task.h"
  34 #include "smbd/service_stream.h"
  35 #include "smbd/service.h"
  36 #include "smbd/process_model.h"
  37 #include "lib/tls/tls.h"
  38 #include "lib/messaging/irpc.h"
  39 #include "lib/ldb/include/ldb.h"
  40 #include "lib/ldb/include/ldb_errors.h"
  41 #include "system/network.h"
  42 #include "lib/socket/netif.h"
  43 #include "dsdb/samdb/samdb.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
 103                 msg = call->replies->msg;
 104                 if (!ldap_encode(msg, &b, call)) {
 105                         DEBUG(0,("Failed to encode ldap reply of type %d\n", msg->type));
 106                         talloc_free(call);
 107                         return;
 108                 }
 109
 110                 status = data_blob_append(call, &blob, b.data, b.length);
 111                 data_blob_free(&b);
 112
 113                 talloc_set_name_const(blob.data, "Outgoing, encoded LDAP packet");
 114
 115                 if (!NT_STATUS_IS_OK(status)) {
 116                         talloc_free(call);
 117                         return;
 118                 }
 119
 120                 DLIST_REMOVE(call->replies, call->replies);
 121         }
 122
 123         packet_send_callback(conn->packet, blob,
 124                              call->send_callback, call->send_private);
 125         talloc_free(call);
 126         return;
 127 }
 128
 129 /*
 130   decode/process data
 131 */
 132 static NTSTATUS ldapsrv_decode(void *private, DATA_BLOB blob)
 133 {
 134         struct ldapsrv_connection *conn = talloc_get_type(private,
 135                                                           struct ldapsrv_connection);
 136         struct asn1_data asn1;
 137         struct ldap_message *msg = talloc(conn, struct ldap_message);
 138
 139         if (msg == NULL) {
 140                 return NT_STATUS_NO_MEMORY;
 141         }
 142
 143         if (!asn1_load(&asn1, blob)) {
 144                 return NT_STATUS_NO_MEMORY;
 145         }
 146
 147         if (!ldap_decode(&asn1, msg)) {
 148                 asn1_free(&asn1);
 149                 return NT_STATUS_LDAP(LDAP_PROTOCOL_ERROR);
 150         }
 151
 152         data_blob_free(&blob);
 153         ldapsrv_process_message(conn, msg);
 154         asn1_free(&asn1);
 155         return NT_STATUS_OK;
 156 }
 157
 158 /*
 159  Idle timeout handler
 160 */
 161 static void ldapsrv_conn_idle_timeout(struct event_context *ev,
 162                                       struct timed_event *te,
 163                                       struct timeval t,
 164                                       void *private)
 165 {
 166         struct ldapsrv_connection *conn = talloc_get_type(private, struct ldapsrv_connection);
 167
 168         ldapsrv_terminate_connection(conn, "Timeout. No requests after bind");
 169 }
 170
 171 /*
 172   called when a LDAP socket becomes readable
 173 */
 174 void ldapsrv_recv(struct stream_connection *c, uint16_t flags)
 175 {
 176         struct ldapsrv_connection *conn =
 177                 talloc_get_type(c->private, struct ldapsrv_connection);
 178
 179         if (conn->limits.ite) { /* clean initial timeout if any */
 180                 talloc_free(conn->limits.ite);
 181                 conn->limits.ite = NULL;
 182         }
 183
 184         if (conn->limits.te) { /* clean idle timeout if any */
 185                 talloc_free(conn->limits.te);
 186                 conn->limits.te = NULL;
 187         }
 188
 189         packet_recv(conn->packet);
 190
 191         /* set idle timeout */
 192         conn->limits.te = event_add_timed(c->event.ctx, conn,
 193                                            timeval_current_ofs(conn->limits.conn_idle_time, 0),
 194                                            ldapsrv_conn_idle_timeout, conn);
 195 }
 196
 197 /*
 198   called when a LDAP socket becomes writable
 199 */
 200 static void ldapsrv_send(struct stream_connection *c, uint16_t flags)
 201 {
 202         struct ldapsrv_connection *conn =
 203                 talloc_get_type(c->private, struct ldapsrv_connection);
 204
 205         packet_queue_run(conn->packet);
 206 }
 207
 208 static void ldapsrv_conn_init_timeout(struct event_context *ev,
 209                                       struct timed_event *te,
 210                                       struct timeval t,
 211                                       void *private)
 212 {
 213         struct ldapsrv_connection *conn = talloc_get_type(private, struct ldapsrv_connection);
 214
 215         ldapsrv_terminate_connection(conn, "Timeout. No requests after initial connection");
 216 }
 217
 218 static int ldapsrv_load_limits(struct ldapsrv_connection *conn)
 219 {
 220         TALLOC_CTX *tmp_ctx;
 221         const char *attrs[] = { "configurationNamingContext", NULL };
 222         const char *attrs2[] = { "lDAPAdminLimits", NULL };
 223         struct ldb_message_element *el;
 224         struct ldb_result *res = NULL;
 225         struct ldb_dn *basedn;
 226         struct ldb_dn *conf_dn;
 227         struct ldb_dn *policy_dn;
 228         int i,ret;
 229
 230         /* set defaults limits in case of failure */
 231         conn->limits.initial_timeout = 120;
 232         conn->limits.conn_idle_time = 900;
 233         conn->limits.max_page_size = 1000;
 234         conn->limits.search_timeout = 120;
 235
 236
 237         tmp_ctx = talloc_new(conn);
 238         if (tmp_ctx == NULL) {
 239                 return -1;
 240         }
 241
 242         basedn = ldb_dn_new(tmp_ctx, conn->ldb, NULL);
 243         if ( ! ldb_dn_validate(basedn)) {
 244                 goto failed;
 245         }
 246
 247         ret = ldb_search(conn->ldb, basedn, LDB_SCOPE_BASE, NULL, attrs, &res);
 248         if (ret != LDB_SUCCESS) {
 249                 goto failed;
 250         }
 251
 252         talloc_steal(tmp_ctx, res);
 253
 254         if (res->count != 1) {
 255                 goto failed;
 256         }
 257
 258         conf_dn = ldb_msg_find_attr_as_dn(conn->ldb, tmp_ctx, res->msgs[0], "configurationNamingContext");
 259         if (conf_dn == NULL) {
 260                 goto failed;
 261         }
 262
 263         policy_dn = ldb_dn_copy(tmp_ctx, conf_dn);
 264         ldb_dn_add_child_fmt(policy_dn, "CN=Default Query Policy,CN=Query-Policies,CN=Directory Service,CN=Windows NT,CN=Services");
 265         if (policy_dn == NULL) {
 266                 goto failed;
 267         }
 268
 269         ret = ldb_search(conn->ldb, policy_dn, LDB_SCOPE_BASE, NULL, attrs2, &res);
 270         if (ret != LDB_SUCCESS) {
 271                 goto failed;
 272         }
 273
 274         talloc_steal(tmp_ctx, res);
 275
 276         if (res->count != 1) {
 277                 goto failed;
 278         }
 279
 280         el = ldb_msg_find_element(res->msgs[0], "lDAPAdminLimits");
 281         if (el == NULL) {
 282                 goto failed;
 283         }
 284
 285         for (i = 0; i < el->num_values; i++) {
 286                 char policy_name[256];
 287                 int policy_value, s;
 288
 289                 s = sscanf((const char *)el->values[i].data, "%255[^=]=%d", policy_name, &policy_value);
 290                 if (ret != 2 || policy_value == 0)
 291                         continue;
 292
 293                 if (strcasecmp("InitRecvTimeout", policy_name) == 0) {
 294                         conn->limits.initial_timeout = policy_value;
 295                         continue;
 296                 }
 297                 if (strcasecmp("MaxConnIdleTime", policy_name) == 0) {
 298                         conn->limits.conn_idle_time = policy_value;
 299                         continue;
 300                 }
 301                 if (strcasecmp("MaxPageSize", policy_name) == 0) {
 302                         conn->limits.max_page_size = policy_value;
 303                         continue;
 304                 }
 305                 if (strcasecmp("MaxQueryDuration", policy_name) == 0) {
 306                         conn->limits.search_timeout = policy_value;
 307                         continue;
 308                 }
 309         }
 310
 311         return 0;
 312
 313 failed:
 314         DEBUG(0, ("Failed to load ldap server query policies\n"));
 315         talloc_free(tmp_ctx);
 316         return -1;
 317 }
 318
 319 /*
 320   initialise a server_context from a open socket and register a event handler
 321   for reading from that socket
 322 */
 323 static void ldapsrv_accept(struct stream_connection *c)
 324 {
 325         struct ldapsrv_service *ldapsrv_service =
 326                 talloc_get_type(c->private, struct ldapsrv_service);
 327         struct ldapsrv_connection *conn;
 328         struct cli_credentials *server_credentials;
 329         struct socket_address *socket_address;
 330         NTSTATUS status;
 331         int port;
 332
 333         conn = talloc_zero(c, struct ldapsrv_connection);
 334         if (!conn) {
 335                 stream_terminate_connection(c, "ldapsrv_accept: out of memory");
 336                 return;
 337         }
 338
 339         conn->packet      = NULL;
 340         conn->connection  = c;
 341         conn->service     = ldapsrv_service;
 342         conn->sockets.raw = c->socket;
 343
 344         c->private        = conn;
 345
 346         socket_address = socket_get_my_addr(c->socket, conn);
 347         if (!socket_address) {
 348                 ldapsrv_terminate_connection(conn, "ldapsrv_accept: failed to obtain local socket address!");
 349                 return;
 350         }
 351         port = socket_address->port;
 352         talloc_free(socket_address);
 353
 354         if (port == 636) {
 355                 struct socket_context *tls_socket = tls_init_server(ldapsrv_service->tls_params, c->socket,
 356                                                                     c->event.fde, NULL);
 357                 if (!tls_socket) {
 358                         ldapsrv_terminate_connection(conn, "ldapsrv_accept: tls_init_server() failed");
 359                         return;
 360                 }
 361                 talloc_unlink(c, c->socket);
 362                 talloc_steal(c, tls_socket);
 363                 c->socket = tls_socket;
 364                 conn->sockets.tls = tls_socket;
 365
 366         } else if (port == 3268) /* Global catalog */ {
 367                 conn->global_catalog = True;
 368         }
 369         conn->packet = packet_init(conn);
 370         if (conn->packet == NULL) {
 371                 ldapsrv_terminate_connection(conn, "out of memory");
 372                 return;
 373         }
 374
 375         packet_set_private(conn->packet, conn);
 376         packet_set_socket(conn->packet, c->socket);
 377         packet_set_callback(conn->packet, ldapsrv_decode);
 378         packet_set_full_request(conn->packet, ldap_full_packet);
 379         packet_set_error_handler(conn->packet, ldapsrv_error_handler);
 380         packet_set_event_context(conn->packet, c->event.ctx);
 381         packet_set_fde(conn->packet, c->event.fde);
 382         packet_set_serialise(conn->packet);
 383
 384         /* Ensure we don't get packets until the database is ready below */
 385         packet_recv_disable(conn->packet);
 386
 387         server_credentials
 388                 = cli_credentials_init(conn);
 389         if (!server_credentials) {
 390                 stream_terminate_connection(c, "Failed to init server credentials\n");
 391                 return;
 392         }
 393
 394         cli_credentials_set_conf(server_credentials);
 395         status = cli_credentials_set_machine_account(server_credentials);
 396         if (!NT_STATUS_IS_OK(status)) {
 397                 stream_terminate_connection(c, talloc_asprintf(conn, "Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(status)));
 398                 return;
 399         }
 400         conn->server_credentials = server_credentials;
 401
 402         /* Connections start out anonymous */
 403         if (!NT_STATUS_IS_OK(auth_anonymous_session_info(conn, &conn->session_info))) {
 404                 ldapsrv_terminate_connection(conn, "failed to setup anonymous session info");
 405                 return;
 406         }
 407
 408         if (!NT_STATUS_IS_OK(ldapsrv_backend_Init(conn))) {
 409                 ldapsrv_terminate_connection(conn, "backend Init failed");
 410                 return;
 411         }
 412
 413         /* load limits from the conf partition */
 414         ldapsrv_load_limits(conn); /* should we fail on error ? */
 415
 416         /* register the server */
 417         irpc_add_name(c->msg_ctx, "ldap_server");
 418
 419         /* set connections limits */
 420         conn->limits.ite = event_add_timed(c->event.ctx, conn,
 421                                            timeval_current_ofs(conn->limits.initial_timeout, 0),
 422                                            ldapsrv_conn_init_timeout, conn);
 423
 424         packet_recv_enable(conn->packet);
 425
 426 }
 427
 428 static const struct stream_server_ops ldap_stream_ops = {
 429         .name                   = "ldap",
 430         .accept_connection      = ldapsrv_accept,
 431         .recv_handler           = ldapsrv_recv,
 432         .send_handler           = ldapsrv_send,
 433 };
 434
 435 /*
 436   add a socket address to the list of events, one event per port
 437 */
 438 static NTSTATUS add_socket(struct event_context *event_context,
 439                            const struct model_ops *model_ops,
 440                            const char *address, struct ldapsrv_service *ldap_service)
 441 {
 442         uint16_t port = 389;
 443         NTSTATUS status;
 444         const char *attrs[] = { "options", NULL };
 445         int ret;
 446         struct ldb_result *res;
 447         struct ldb_context *ldb;
 448         int options;
 449
 450         status = stream_setup_socket(event_context, model_ops, &ldap_stream_ops,
 451                                      "ipv4", address, &port, ldap_service);
 452         if (!NT_STATUS_IS_OK(status)) {
 453                 DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
 454                          address, port, nt_errstr(status)));
 455         }
 456
 457         if (tls_support(ldap_service->tls_params)) {
 458                 /* add ldaps server */
 459                 port = 636;
 460                 status = stream_setup_socket(event_context, model_ops, &ldap_stream_ops,
 461                                              "ipv4", address, &port, ldap_service);
 462                 if (!NT_STATUS_IS_OK(status)) {
 463                         DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
 464                                  address, port, nt_errstr(status)));
 465                 }
 466         }
 467
 468         /* Load LDAP database */
 469         ldb = samdb_connect(ldap_service, system_session(ldap_service));
 470         if (!ldb) {
 471                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 472         }
 473
 474         /* Query cn=ntds settings,.... */
 475         ret = ldb_search(ldb, samdb_ntds_settings_dn(ldb), LDB_SCOPE_BASE, NULL, attrs, &res);
 476         if (ret) {
 477                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 478         }
 479         if (res->count != 1) {
 480                 talloc_free(res);
 481                 return NT_STATUS_NOT_FOUND;
 482         }
 483
 484         options = ldb_msg_find_attr_as_int(res->msgs[0], "options", 0);
 485         talloc_free(res);
 486         talloc_free(ldb);
 487
 488         /* if options attribute has the 0x00000001 flag set, then enable the global catlog */
 489         if (options & 0x000000001) {
 490                 port = 3268;
 491                 status = stream_setup_socket(event_context, model_ops, &ldap_stream_ops,
 492                                              "ipv4", address, &port, ldap_service);
 493                 if (!NT_STATUS_IS_OK(status)) {
 494                         DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
 495                                  address, port, nt_errstr(status)));
 496                 }
 497         }
 498
 499         return status;
 500 }
 501
 502 /*
 503   open the ldap server sockets
 504 */
 505 static void ldapsrv_task_init(struct task_server *task)
 506 {
 507         struct ldapsrv_service *ldap_service;
 508         NTSTATUS status;
 509         const struct model_ops *model_ops;
 510
 511         task_server_set_title(task, "task[ldapsrv]");
 512
 513         /* run the ldap server as a single process */
 514         model_ops = process_model_byname("single");
 515         if (!model_ops) goto failed;
 516
 517         ldap_service = talloc_zero(task, struct ldapsrv_service);
 518         if (ldap_service == NULL) goto failed;
 519
 520         ldap_service->tls_params = tls_initialise(ldap_service);
 521         if (ldap_service->tls_params == NULL) goto failed;
 522
 523         if (lp_interfaces() && lp_bind_interfaces_only()) {
 524                 int num_interfaces = iface_count();
 525                 int i;
 526
 527                 /* We have been given an interfaces line, and been
 528                    told to only bind to those interfaces. Create a
 529                    socket per interface and bind to only these.
 530                 */
 531                 for(i = 0; i < num_interfaces; i++) {
 532                         const char *address = iface_n_ip(i);
 533                         status = add_socket(task->event_ctx, model_ops, address, ldap_service);
 534                         if (!NT_STATUS_IS_OK(status)) goto failed;
 535                 }
 536         } else {
 537                 status = add_socket(task->event_ctx, model_ops, lp_socket_address(), ldap_service);
 538                 if (!NT_STATUS_IS_OK(status)) goto failed;
 539         }
 540
 541         return;
 542
 543 failed:
 544         task_server_terminate(task, "Failed to startup ldap server task");
 545 }
 546
 547 /*
 548   called on startup of the web server service It's job is to start
 549   listening on all configured sockets
 550 */
 551 static NTSTATUS ldapsrv_init(struct event_context *event_context,
 552                              const struct model_ops *model_ops)
 553 {
 554         return task_server_startup(event_context, model_ops, ldapsrv_task_init);
 555 }
 556
 557
 558 NTSTATUS server_service_ldap_init(void)
 559 {
 560         return register_server_service("ldap", ldapsrv_init);
 561 }