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         NTSTATUS status;
 135         struct ldapsrv_connection *conn = talloc_get_type(private,
 136                                                           struct ldapsrv_connection);
 137         struct asn1_data asn1;
 138         struct ldap_message *msg = talloc(conn, struct ldap_message);
 139
 140         if (msg == NULL) {
 141                 return NT_STATUS_NO_MEMORY;
 142         }
 143
 144         if (!asn1_load(&asn1, blob)) {
 145                 return NT_STATUS_NO_MEMORY;
 146         }
 147
 148         status = ldap_decode(&asn1, msg);
 149         if (!NT_STATUS_IS_OK(status)) {
 150                 asn1_free(&asn1);
 151                 return status;
 152         }
 153
 154         data_blob_free(&blob);
 155         ldapsrv_process_message(conn, msg);
 156         asn1_free(&asn1);
 157         return NT_STATUS_OK;
 158 }
 159
 160 /*
 161  Idle timeout handler
 162 */
 163 static void ldapsrv_conn_idle_timeout(struct event_context *ev,
 164                                       struct timed_event *te,
 165                                       struct timeval t,
 166                                       void *private)
 167 {
 168         struct ldapsrv_connection *conn = talloc_get_type(private, struct ldapsrv_connection);
 169
 170         ldapsrv_terminate_connection(conn, "Timeout. No requests after bind");
 171 }
 172
 173 /*
 174   called when a LDAP socket becomes readable
 175 */
 176 void ldapsrv_recv(struct stream_connection *c, uint16_t flags)
 177 {
 178         struct ldapsrv_connection *conn =
 179                 talloc_get_type(c->private, struct ldapsrv_connection);
 180
 181         if (conn->limits.ite) { /* clean initial timeout if any */
 182                 talloc_free(conn->limits.ite);
 183                 conn->limits.ite = NULL;
 184         }
 185
 186         if (conn->limits.te) { /* clean idle timeout if any */
 187                 talloc_free(conn->limits.te);
 188                 conn->limits.te = NULL;
 189         }
 190
 191         packet_recv(conn->packet);
 192
 193         /* set idle timeout */
 194         conn->limits.te = event_add_timed(c->event.ctx, conn,
 195                                            timeval_current_ofs(conn->limits.conn_idle_time, 0),
 196                                            ldapsrv_conn_idle_timeout, conn);
 197 }
 198
 199 /*
 200   called when a LDAP socket becomes writable
 201 */
 202 static void ldapsrv_send(struct stream_connection *c, uint16_t flags)
 203 {
 204         struct ldapsrv_connection *conn =
 205                 talloc_get_type(c->private, struct ldapsrv_connection);
 206
 207         packet_queue_run(conn->packet);
 208 }
 209
 210 static void ldapsrv_conn_init_timeout(struct event_context *ev,
 211                                       struct timed_event *te,
 212                                       struct timeval t,
 213                                       void *private)
 214 {
 215         struct ldapsrv_connection *conn = talloc_get_type(private, struct ldapsrv_connection);
 216
 217         ldapsrv_terminate_connection(conn, "Timeout. No requests after initial connection");
 218 }
 219
 220 static int ldapsrv_load_limits(struct ldapsrv_connection *conn)
 221 {
 222         TALLOC_CTX *tmp_ctx;
 223         const char *attrs[] = { "configurationNamingContext", NULL };
 224         const char *attrs2[] = { "lDAPAdminLimits", NULL };
 225         struct ldb_message_element *el;
 226         struct ldb_result *res = NULL;
 227         struct ldb_dn *basedn;
 228         struct ldb_dn *conf_dn;
 229         struct ldb_dn *policy_dn;
 230         int i,ret;
 231
 232         /* set defaults limits in case of failure */
 233         conn->limits.initial_timeout = 120;
 234         conn->limits.conn_idle_time = 900;
 235         conn->limits.max_page_size = 1000;
 236         conn->limits.search_timeout = 120;
 237
 238
 239         tmp_ctx = talloc_new(conn);
 240         if (tmp_ctx == NULL) {
 241                 return -1;
 242         }
 243
 244         basedn = ldb_dn_new(tmp_ctx, conn->ldb, NULL);
 245         if ( ! ldb_dn_validate(basedn)) {
 246                 goto failed;
 247         }
 248
 249         ret = ldb_search(conn->ldb, basedn, LDB_SCOPE_BASE, NULL, attrs, &res);
 250         if (ret != LDB_SUCCESS) {
 251                 goto failed;
 252         }
 253
 254         talloc_steal(tmp_ctx, res);
 255
 256         if (res->count != 1) {
 257                 goto failed;
 258         }
 259
 260         conf_dn = ldb_msg_find_attr_as_dn(conn->ldb, tmp_ctx, res->msgs[0], "configurationNamingContext");
 261         if (conf_dn == NULL) {
 262                 goto failed;
 263         }
 264
 265         policy_dn = ldb_dn_copy(tmp_ctx, conf_dn);
 266         ldb_dn_add_child_fmt(policy_dn, "CN=Default Query Policy,CN=Query-Policies,CN=Directory Service,CN=Windows NT,CN=Services");
 267         if (policy_dn == NULL) {
 268                 goto failed;
 269         }
 270
 271         ret = ldb_search(conn->ldb, policy_dn, LDB_SCOPE_BASE, NULL, attrs2, &res);
 272         if (ret != LDB_SUCCESS) {
 273                 goto failed;
 274         }
 275
 276         talloc_steal(tmp_ctx, res);
 277
 278         if (res->count != 1) {
 279                 goto failed;
 280         }
 281
 282         el = ldb_msg_find_element(res->msgs[0], "lDAPAdminLimits");
 283         if (el == NULL) {
 284                 goto failed;
 285         }
 286
 287         for (i = 0; i < el->num_values; i++) {
 288                 char policy_name[256];
 289                 int policy_value, s;
 290
 291                 s = sscanf((const char *)el->values[i].data, "%255[^=]=%d", policy_name, &policy_value);
 292                 if (ret != 2 || policy_value == 0)
 293                         continue;
 294
 295                 if (strcasecmp("InitRecvTimeout", policy_name) == 0) {
 296                         conn->limits.initial_timeout = policy_value;
 297                         continue;
 298                 }
 299                 if (strcasecmp("MaxConnIdleTime", policy_name) == 0) {
 300                         conn->limits.conn_idle_time = policy_value;
 301                         continue;
 302                 }
 303                 if (strcasecmp("MaxPageSize", policy_name) == 0) {
 304                         conn->limits.max_page_size = policy_value;
 305                         continue;
 306                 }
 307                 if (strcasecmp("MaxQueryDuration", policy_name) == 0) {
 308                         conn->limits.search_timeout = policy_value;
 309                         continue;
 310                 }
 311         }
 312
 313         return 0;
 314
 315 failed:
 316         DEBUG(0, ("Failed to load ldap server query policies\n"));
 317         talloc_free(tmp_ctx);
 318         return -1;
 319 }
 320
 321 /*
 322   initialise a server_context from a open socket and register a event handler
 323   for reading from that socket
 324 */
 325 static void ldapsrv_accept(struct stream_connection *c)
 326 {
 327         struct ldapsrv_service *ldapsrv_service =
 328                 talloc_get_type(c->private, struct ldapsrv_service);
 329         struct ldapsrv_connection *conn;
 330         struct cli_credentials *server_credentials;
 331         struct socket_address *socket_address;
 332         NTSTATUS status;
 333         int port;
 334
 335         conn = talloc_zero(c, struct ldapsrv_connection);
 336         if (!conn) {
 337                 stream_terminate_connection(c, "ldapsrv_accept: out of memory");
 338                 return;
 339         }
 340
 341         conn->packet      = NULL;
 342         conn->connection  = c;
 343         conn->service     = ldapsrv_service;
 344         conn->sockets.raw = c->socket;
 345
 346         c->private        = conn;
 347
 348         socket_address = socket_get_my_addr(c->socket, conn);
 349         if (!socket_address) {
 350                 ldapsrv_terminate_connection(conn, "ldapsrv_accept: failed to obtain local socket address!");
 351                 return;
 352         }
 353         port = socket_address->port;
 354         talloc_free(socket_address);
 355
 356         if (port == 636) {
 357                 struct socket_context *tls_socket = tls_init_server(ldapsrv_service->tls_params, c->socket,
 358                                                                     c->event.fde, NULL);
 359                 if (!tls_socket) {
 360                         ldapsrv_terminate_connection(conn, "ldapsrv_accept: tls_init_server() failed");
 361                         return;
 362                 }
 363                 talloc_unlink(c, c->socket);
 364                 talloc_steal(c, tls_socket);
 365                 c->socket = tls_socket;
 366                 conn->sockets.tls = tls_socket;
 367
 368         } else if (port == 3268) /* Global catalog */ {
 369                 conn->global_catalog = True;
 370         }
 371         conn->packet = packet_init(conn);
 372         if (conn->packet == NULL) {
 373                 ldapsrv_terminate_connection(conn, "out of memory");
 374                 return;
 375         }
 376
 377         packet_set_private(conn->packet, conn);
 378         packet_set_socket(conn->packet, c->socket);
 379         packet_set_callback(conn->packet, ldapsrv_decode);
 380         packet_set_full_request(conn->packet, ldap_full_packet);
 381         packet_set_error_handler(conn->packet, ldapsrv_error_handler);
 382         packet_set_event_context(conn->packet, c->event.ctx);
 383         packet_set_fde(conn->packet, c->event.fde);
 384         packet_set_serialise(conn->packet);
 385
 386         /* Ensure we don't get packets until the database is ready below */
 387         packet_recv_disable(conn->packet);
 388
 389         server_credentials
 390                 = cli_credentials_init(conn);
 391         if (!server_credentials) {
 392                 stream_terminate_connection(c, "Failed to init server credentials\n");
 393                 return;
 394         }
 395
 396         cli_credentials_set_conf(server_credentials);
 397         status = cli_credentials_set_machine_account(server_credentials);
 398         if (!NT_STATUS_IS_OK(status)) {
 399                 stream_terminate_connection(c, talloc_asprintf(conn, "Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(status)));
 400                 return;
 401         }
 402         conn->server_credentials = server_credentials;
 403
 404         /* Connections start out anonymous */
 405         if (!NT_STATUS_IS_OK(auth_anonymous_session_info(conn, &conn->session_info))) {
 406                 ldapsrv_terminate_connection(conn, "failed to setup anonymous session info");
 407                 return;
 408         }
 409
 410         if (!NT_STATUS_IS_OK(ldapsrv_backend_Init(conn))) {
 411                 ldapsrv_terminate_connection(conn, "backend Init failed");
 412                 return;
 413         }
 414
 415         /* load limits from the conf partition */
 416         ldapsrv_load_limits(conn); /* should we fail on error ? */
 417
 418         /* register the server */
 419         irpc_add_name(c->msg_ctx, "ldap_server");
 420
 421         /* set connections limits */
 422         conn->limits.ite = event_add_timed(c->event.ctx, conn,
 423                                            timeval_current_ofs(conn->limits.initial_timeout, 0),
 424                                            ldapsrv_conn_init_timeout, conn);
 425
 426         packet_recv_enable(conn->packet);
 427
 428 }
 429
 430 static const struct stream_server_ops ldap_stream_ops = {
 431         .name                   = "ldap",
 432         .accept_connection      = ldapsrv_accept,
 433         .recv_handler           = ldapsrv_recv,
 434         .send_handler           = ldapsrv_send,
 435 };
 436
 437 /*
 438   add a socket address to the list of events, one event per port
 439 */
 440 static NTSTATUS add_socket(struct event_context *event_context,
 441                            const struct model_ops *model_ops,
 442                            const char *address, struct ldapsrv_service *ldap_service)
 443 {
 444         uint16_t port = 389;
 445         NTSTATUS status;
 446         const char *attrs[] = { "options", NULL };
 447         int ret;
 448         struct ldb_result *res;
 449         struct ldb_context *ldb;
 450         int options;
 451
 452         status = stream_setup_socket(event_context, model_ops, &ldap_stream_ops,
 453                                      "ipv4", address, &port, ldap_service);
 454         if (!NT_STATUS_IS_OK(status)) {
 455                 DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
 456                          address, port, nt_errstr(status)));
 457         }
 458
 459         if (tls_support(ldap_service->tls_params)) {
 460                 /* add ldaps server */
 461                 port = 636;
 462                 status = stream_setup_socket(event_context, model_ops, &ldap_stream_ops,
 463                                              "ipv4", address, &port, ldap_service);
 464                 if (!NT_STATUS_IS_OK(status)) {
 465                         DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
 466                                  address, port, nt_errstr(status)));
 467                 }
 468         }
 469
 470         /* Load LDAP database */
 471         ldb = samdb_connect(ldap_service, system_session(ldap_service));
 472         if (!ldb) {
 473                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 474         }
 475
 476         /* Query cn=ntds settings,.... */
 477         ret = ldb_search(ldb, samdb_ntds_settings_dn(ldb), LDB_SCOPE_BASE, NULL, attrs, &res);
 478         if (ret) {
 479                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 480         }
 481         if (res->count != 1) {
 482                 talloc_free(res);
 483                 return NT_STATUS_NOT_FOUND;
 484         }
 485
 486         options = ldb_msg_find_attr_as_int(res->msgs[0], "options", 0);
 487         talloc_free(res);
 488         talloc_free(ldb);
 489
 490         /* if options attribute has the 0x00000001 flag set, then enable the global catlog */
 491         if (options & 0x000000001) {
 492                 port = 3268;
 493                 status = stream_setup_socket(event_context, model_ops, &ldap_stream_ops,
 494                                              "ipv4", address, &port, ldap_service);
 495                 if (!NT_STATUS_IS_OK(status)) {
 496                         DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
 497                                  address, port, nt_errstr(status)));
 498                 }
 499         }
 500
 501         return status;
 502 }
 503
 504 /*
 505   open the ldap server sockets
 506 */
 507 static void ldapsrv_task_init(struct task_server *task)
 508 {
 509         struct ldapsrv_service *ldap_service;
 510         NTSTATUS status;
 511         const struct model_ops *model_ops;
 512
 513         task_server_set_title(task, "task[ldapsrv]");
 514
 515         /* run the ldap server as a single process */
 516         model_ops = process_model_byname("single");
 517         if (!model_ops) goto failed;
 518
 519         ldap_service = talloc_zero(task, struct ldapsrv_service);
 520         if (ldap_service == NULL) goto failed;
 521
 522         ldap_service->tls_params = tls_initialise(ldap_service);
 523         if (ldap_service->tls_params == NULL) goto failed;
 524
 525         if (lp_interfaces() && lp_bind_interfaces_only()) {
 526                 int num_interfaces = iface_count();
 527                 int i;
 528
 529                 /* We have been given an interfaces line, and been
 530                    told to only bind to those interfaces. Create a
 531                    socket per interface and bind to only these.
 532                 */
 533                 for(i = 0; i < num_interfaces; i++) {
 534                         const char *address = iface_n_ip(i);
 535                         status = add_socket(task->event_ctx, model_ops, address, ldap_service);
 536                         if (!NT_STATUS_IS_OK(status)) goto failed;
 537                 }
 538         } else {
 539                 status = add_socket(task->event_ctx, model_ops, lp_socket_address(), ldap_service);
 540                 if (!NT_STATUS_IS_OK(status)) goto failed;
 541         }
 542
 543         return;
 544
 545 failed:
 546         task_server_terminate(task, "Failed to startup ldap server task");
 547 }
 548
 549 /*
 550   called on startup of the web server service It's job is to start
 551   listening on all configured sockets
 552 */
 553 static NTSTATUS ldapsrv_init(struct event_context *event_context,
 554                              const struct model_ops *model_ops)
 555 {
 556         return task_server_startup(event_context, model_ops, ldapsrv_task_init);
 557 }
 558
 559
 560 NTSTATUS server_service_ldap_init(void)
 561 {
 562         return register_server_service("ldap", ldapsrv_init);
 563 }