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