s4:ldap_server: don't start if we can't bind to port 389
[amitay/samba.git] / 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 "../lib/util/asn1.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 "libcli/ldap/ldap_proto.h"
41 #include "system/network.h"
42 #include "lib/socket/netif.h"
43 #include "dsdb/samdb/samdb.h"
44 #include "param/param.h"
45 /*
46   close the socket and shutdown a server_context
47 */
48 void ldapsrv_terminate_connection(struct ldapsrv_connection *conn, 
49                                          const char *reason)
50 {
51         packet_recv_disable(conn->packet);
52         TALLOC_FREE(conn->packet);
53         TALLOC_FREE(conn->sockets.tls);
54         stream_terminate_connection(conn->connection, reason);
55 }
56
57 /*
58   handle packet errors
59 */
60 static void ldapsrv_error_handler(void *private_data, NTSTATUS status)
61 {
62         struct ldapsrv_connection *conn = talloc_get_type(private_data,
63                                                           struct ldapsrv_connection);
64         ldapsrv_terminate_connection(conn, nt_errstr(status));
65 }
66
67 /*
68   process a decoded ldap message
69 */
70 static void ldapsrv_process_message(struct ldapsrv_connection *conn,
71                                     struct ldap_message *msg)
72 {
73         struct ldapsrv_call *call;
74         NTSTATUS status;
75         DATA_BLOB blob;
76
77         call = talloc(conn, struct ldapsrv_call);
78         if (!call) {
79                 ldapsrv_terminate_connection(conn, "no memory");
80                 return;         
81         }
82
83         call->request = talloc_steal(call, msg);
84         call->conn = conn;
85         call->replies = NULL;
86         call->send_callback = NULL;
87         call->send_private = NULL;
88
89         /* make the call */
90         status = ldapsrv_do_call(call);
91         if (!NT_STATUS_IS_OK(status)) {
92                 talloc_free(call);
93                 return;
94         }
95
96         blob = data_blob(NULL, 0);
97
98         if (call->replies == NULL) {
99                 talloc_free(call);
100                 return;
101         }
102
103         /* build all the replies into a single blob */
104         while (call->replies) {
105                 DATA_BLOB b;
106                 bool ret;
107
108                 msg = call->replies->msg;
109                 if (!ldap_encode(msg, samba_ldap_control_handlers(), &b, call)) {
110                         DEBUG(0,("Failed to encode ldap reply of type %d\n", msg->type));
111                         talloc_free(call);
112                         return;
113                 }
114
115                 ret = data_blob_append(call, &blob, b.data, b.length);
116                 data_blob_free(&b);
117
118                 talloc_set_name_const(blob.data, "Outgoing, encoded LDAP packet");
119
120                 if (!ret) {
121                         talloc_free(call);
122                         return;
123                 }
124
125                 DLIST_REMOVE(call->replies, call->replies);
126         }
127
128         packet_send_callback(conn->packet, blob, 
129                              call->send_callback, call->send_private);
130         talloc_free(call);
131         return;
132 }
133
134 /*
135   decode/process data
136 */
137 static NTSTATUS ldapsrv_decode(void *private_data, DATA_BLOB blob)
138 {
139         NTSTATUS status;
140         struct ldapsrv_connection *conn = talloc_get_type(private_data,
141                                                           struct ldapsrv_connection);
142         struct asn1_data *asn1 = asn1_init(conn);
143         struct ldap_message *msg = talloc(conn, struct ldap_message);
144
145         if (asn1 == NULL || msg == NULL) {
146                 return NT_STATUS_NO_MEMORY;
147         }
148
149         if (!asn1_load(asn1, blob)) {
150                 talloc_free(msg);
151                 talloc_free(asn1);
152                 return NT_STATUS_NO_MEMORY;
153         }
154
155         status = ldap_decode(asn1, samba_ldap_control_handlers(), msg);
156         if (!NT_STATUS_IS_OK(status)) {
157                 asn1_free(asn1);
158                 return status;
159         }
160
161         data_blob_free(&blob);
162         talloc_steal(conn, msg);
163         asn1_free(asn1);
164
165         ldapsrv_process_message(conn, msg);
166         return NT_STATUS_OK;
167 }
168
169 /*
170  Idle timeout handler
171 */
172 static void ldapsrv_conn_idle_timeout(struct tevent_context *ev,
173                                       struct tevent_timer *te,
174                                       struct timeval t,
175                                       void *private_data)
176 {
177         struct ldapsrv_connection *conn = talloc_get_type(private_data, struct ldapsrv_connection);
178
179         ldapsrv_terminate_connection(conn, "Timeout. No requests after bind");
180 }
181
182 /*
183   called when a LDAP socket becomes readable
184 */
185 void ldapsrv_recv(struct stream_connection *c, uint16_t flags)
186 {
187         struct ldapsrv_connection *conn = 
188                 talloc_get_type(c->private_data, struct ldapsrv_connection);
189
190         if (conn->limits.ite) { /* clean initial timeout if any */
191                 talloc_free(conn->limits.ite);
192                 conn->limits.ite = NULL;
193         }
194
195         if (conn->limits.te) { /* clean idle timeout if any */
196                 talloc_free(conn->limits.te);
197                 conn->limits.te = NULL;
198         }
199
200         packet_recv(conn->packet);
201
202         /* set idle timeout */
203         conn->limits.te = event_add_timed(c->event.ctx, conn, 
204                                            timeval_current_ofs(conn->limits.conn_idle_time, 0),
205                                            ldapsrv_conn_idle_timeout, conn);
206 }
207
208 /*
209   called when a LDAP socket becomes writable
210 */
211 static void ldapsrv_send(struct stream_connection *c, uint16_t flags)
212 {
213         struct ldapsrv_connection *conn = 
214                 talloc_get_type(c->private_data, struct ldapsrv_connection);
215
216         packet_queue_run(conn->packet);
217 }
218
219 static void ldapsrv_conn_init_timeout(struct tevent_context *ev,
220                                       struct tevent_timer *te,
221                                       struct timeval t,
222                                       void *private_data)
223 {
224         struct ldapsrv_connection *conn = talloc_get_type(private_data, struct ldapsrv_connection);
225
226         ldapsrv_terminate_connection(conn, "Timeout. No requests after initial connection");
227 }
228
229 static int ldapsrv_load_limits(struct ldapsrv_connection *conn)
230 {
231         TALLOC_CTX *tmp_ctx;
232         const char *attrs[] = { "configurationNamingContext", NULL };
233         const char *attrs2[] = { "lDAPAdminLimits", NULL };
234         struct ldb_message_element *el;
235         struct ldb_result *res = NULL;
236         struct ldb_dn *basedn;
237         struct ldb_dn *conf_dn;
238         struct ldb_dn *policy_dn;
239         unsigned int i;
240         int ret;
241
242         /* set defaults limits in case of failure */
243         conn->limits.initial_timeout = 120;
244         conn->limits.conn_idle_time = 900;
245         conn->limits.max_page_size = 1000;
246         conn->limits.search_timeout = 120;
247
248
249         tmp_ctx = talloc_new(conn);
250         if (tmp_ctx == NULL) {
251                 return -1;
252         }
253
254         basedn = ldb_dn_new(tmp_ctx, conn->ldb, NULL);
255         if ( ! ldb_dn_validate(basedn)) {
256                 goto failed;
257         }
258
259         ret = ldb_search(conn->ldb, tmp_ctx, &res, basedn, LDB_SCOPE_BASE, attrs, NULL);
260         if (ret != LDB_SUCCESS) {
261                 goto failed;
262         }
263
264         if (res->count != 1) {
265                 goto failed;
266         }
267
268         conf_dn = ldb_msg_find_attr_as_dn(conn->ldb, tmp_ctx, res->msgs[0], "configurationNamingContext");
269         if (conf_dn == NULL) {
270                 goto failed;
271         }
272
273         policy_dn = ldb_dn_copy(tmp_ctx, conf_dn);
274         ldb_dn_add_child_fmt(policy_dn, "CN=Default Query Policy,CN=Query-Policies,CN=Directory Service,CN=Windows NT,CN=Services");
275         if (policy_dn == NULL) {
276                 goto failed;
277         }
278
279         ret = ldb_search(conn->ldb, tmp_ctx, &res, policy_dn, LDB_SCOPE_BASE, attrs2, NULL);
280         if (ret != LDB_SUCCESS) {
281                 goto failed;
282         }
283
284         if (res->count != 1) {
285                 goto failed;
286         }
287
288         el = ldb_msg_find_element(res->msgs[0], "lDAPAdminLimits");
289         if (el == NULL) {
290                 goto failed;
291         }
292
293         for (i = 0; i < el->num_values; i++) {
294                 char policy_name[256];
295                 int policy_value, s;
296
297                 s = sscanf((const char *)el->values[i].data, "%255[^=]=%d", policy_name, &policy_value);
298                 if (ret != 2 || policy_value == 0)
299                         continue;
300
301                 if (strcasecmp("InitRecvTimeout", policy_name) == 0) {
302                         conn->limits.initial_timeout = policy_value;
303                         continue;
304                 }
305                 if (strcasecmp("MaxConnIdleTime", policy_name) == 0) {
306                         conn->limits.conn_idle_time = policy_value;
307                         continue;
308                 }
309                 if (strcasecmp("MaxPageSize", policy_name) == 0) {
310                         conn->limits.max_page_size = policy_value;
311                         continue;
312                 }
313                 if (strcasecmp("MaxQueryDuration", policy_name) == 0) {
314                         conn->limits.search_timeout = policy_value;
315                         continue;
316                 }
317         }
318
319         return 0;
320
321 failed:
322         DEBUG(0, ("Failed to load ldap server query policies\n"));
323         talloc_free(tmp_ctx);
324         return -1;
325 }
326
327 /*
328   initialise a server_context from a open socket and register a event handler
329   for reading from that socket
330 */
331 static void ldapsrv_accept(struct stream_connection *c,
332                            struct auth_session_info *session_info)
333 {
334         struct ldapsrv_service *ldapsrv_service = 
335                 talloc_get_type(c->private_data, struct ldapsrv_service);
336         struct ldapsrv_connection *conn;
337         struct cli_credentials *server_credentials;
338         struct socket_address *socket_address;
339         NTSTATUS status;
340         int port;
341
342         conn = talloc_zero(c, struct ldapsrv_connection);
343         if (!conn) {
344                 stream_terminate_connection(c, "ldapsrv_accept: out of memory");
345                 return;
346         }
347
348         conn->packet      = NULL;
349         conn->connection  = c;
350         conn->service     = ldapsrv_service;
351         conn->sockets.raw = c->socket;
352         conn->lp_ctx      = ldapsrv_service->task->lp_ctx;
353
354         c->private_data   = conn;
355
356         socket_address = socket_get_my_addr(c->socket, conn);
357         if (!socket_address) {
358                 ldapsrv_terminate_connection(conn, "ldapsrv_accept: failed to obtain local socket address!");
359                 return;
360         }
361         port = socket_address->port;
362         talloc_free(socket_address);
363
364         if (port == 636) {
365                 struct socket_context *tls_socket = tls_init_server(ldapsrv_service->tls_params, c->socket, 
366                                                                     c->event.fde, NULL);
367                 if (!tls_socket) {
368                         ldapsrv_terminate_connection(conn, "ldapsrv_accept: tls_init_server() failed");
369                         return;
370                 }
371                 talloc_steal(c, tls_socket);
372                 c->socket = tls_socket;
373                 conn->sockets.tls = tls_socket;
374
375         } else if (port == 3268) /* Global catalog */ {
376                 conn->global_catalog = true;
377         }
378         conn->packet = packet_init(conn);
379         if (conn->packet == NULL) {
380                 ldapsrv_terminate_connection(conn, "out of memory");
381                 return;
382         }
383
384         packet_set_private(conn->packet, conn);
385         packet_set_socket(conn->packet, c->socket);
386         packet_set_callback(conn->packet, ldapsrv_decode);
387         packet_set_full_request(conn->packet, ldap_full_packet);
388         packet_set_error_handler(conn->packet, ldapsrv_error_handler);
389         packet_set_event_context(conn->packet, c->event.ctx);
390         packet_set_fde(conn->packet, c->event.fde);
391         packet_set_serialise(conn->packet);
392
393         if (conn->sockets.tls) {
394                 packet_set_unreliable_select(conn->packet);
395         }
396
397         /* Ensure we don't get packets until the database is ready below */
398         packet_recv_disable(conn->packet);
399
400         server_credentials = cli_credentials_init(conn);
401         if (!server_credentials) {
402                 stream_terminate_connection(c, "Failed to init server credentials\n");
403                 return;
404         }
405
406         cli_credentials_set_conf(server_credentials, conn->lp_ctx);
407         status = cli_credentials_set_machine_account(server_credentials, conn->lp_ctx);
408         if (!NT_STATUS_IS_OK(status)) {
409                 stream_terminate_connection(c, talloc_asprintf(conn, "Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(status)));
410                 return;
411         }
412         conn->server_credentials = server_credentials;
413
414         conn->session_info = talloc_move(conn, &session_info);
415
416         if (!NT_STATUS_IS_OK(ldapsrv_backend_Init(conn))) {
417                 ldapsrv_terminate_connection(conn, "backend Init failed");
418                 return;
419         }
420
421         /* load limits from the conf partition */
422         ldapsrv_load_limits(conn); /* should we fail on error ? */
423
424         /* register the server */       
425         irpc_add_name(c->msg_ctx, "ldap_server");
426
427         /* set connections limits */
428         conn->limits.ite = event_add_timed(c->event.ctx, conn, 
429                                            timeval_current_ofs(conn->limits.initial_timeout, 0),
430                                            ldapsrv_conn_init_timeout, conn);
431
432         packet_recv_enable(conn->packet);
433
434 }
435
436 static void ldapsrv_accept_nonpriv(struct stream_connection *c)
437 {
438         struct ldapsrv_service *ldapsrv_service = talloc_get_type_abort(
439                 c->private_data, struct ldapsrv_service);
440         struct auth_session_info *session_info;
441         NTSTATUS status;
442
443         status = auth_anonymous_session_info(
444                 c, ldapsrv_service->task->lp_ctx, &session_info);
445         if (!NT_STATUS_IS_OK(status)) {
446                 stream_terminate_connection(c, "failed to setup anonymous "
447                                             "session info");
448                 return;
449         }
450         ldapsrv_accept(c, session_info);
451 }
452
453 static const struct stream_server_ops ldap_stream_nonpriv_ops = {
454         .name                   = "ldap",
455         .accept_connection      = ldapsrv_accept_nonpriv,
456         .recv_handler           = ldapsrv_recv,
457         .send_handler           = ldapsrv_send,
458 };
459
460 /* The feature removed behind an #ifdef until we can do it properly
461  * with an EXTERNAL bind. */
462
463 #define WITH_LDAPI_PRIV_SOCKET
464
465 #ifdef WITH_LDAPI_PRIV_SOCKET
466 static void ldapsrv_accept_priv(struct stream_connection *c)
467 {
468         struct ldapsrv_service *ldapsrv_service = talloc_get_type_abort(
469                 c->private_data, struct ldapsrv_service);
470         struct auth_session_info *session_info;
471
472         session_info = system_session(ldapsrv_service->task->lp_ctx);
473         if (!session_info) {
474                 stream_terminate_connection(c, "failed to setup system "
475                                             "session info");
476                 return;
477         }
478         ldapsrv_accept(c, session_info);
479 }
480
481 static const struct stream_server_ops ldap_stream_priv_ops = {
482         .name                   = "ldap",
483         .accept_connection      = ldapsrv_accept_priv,
484         .recv_handler           = ldapsrv_recv,
485         .send_handler           = ldapsrv_send,
486 };
487
488 #endif
489 /*
490   add a socket address to the list of events, one event per port
491 */
492 static NTSTATUS add_socket(struct tevent_context *event_context,
493                            struct loadparm_context *lp_ctx, 
494                            const struct model_ops *model_ops,
495                            const char *address, struct ldapsrv_service *ldap_service)
496 {
497         uint16_t port = 389;
498         NTSTATUS status;
499         struct ldb_context *ldb;
500
501         status = stream_setup_socket(event_context, lp_ctx,
502                                      model_ops, &ldap_stream_nonpriv_ops,
503                                      "ipv4", address, &port, 
504                                      lp_socket_options(lp_ctx), 
505                                      ldap_service);
506         if (!NT_STATUS_IS_OK(status)) {
507                 DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
508                          address, port, nt_errstr(status)));
509                 return status;
510         }
511
512         if (tls_support(ldap_service->tls_params)) {
513                 /* add ldaps server */
514                 port = 636;
515                 status = stream_setup_socket(event_context, lp_ctx, 
516                                              model_ops,
517                                              &ldap_stream_nonpriv_ops,
518                                              "ipv4", address, &port, 
519                                              lp_socket_options(lp_ctx), 
520                                              ldap_service);
521                 if (!NT_STATUS_IS_OK(status)) {
522                         DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
523                                  address, port, nt_errstr(status)));
524                         return status;
525                 }
526         }
527
528         /* Load LDAP database, but only to read our settings */
529         ldb = samdb_connect(ldap_service, ldap_service->task->event_ctx, 
530                             lp_ctx, system_session(lp_ctx));
531         if (!ldb) {
532                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
533         }
534
535         if (samdb_is_gc(ldb)) {
536                 port = 3268;
537                 status = stream_setup_socket(event_context, lp_ctx,
538                                              model_ops,
539                                              &ldap_stream_nonpriv_ops,
540                                              "ipv4", address, &port, 
541                                              lp_socket_options(lp_ctx), 
542                                              ldap_service);
543                 if (!NT_STATUS_IS_OK(status)) {
544                         DEBUG(0,("ldapsrv failed to bind to %s:%u - %s\n",
545                                  address, port, nt_errstr(status)));
546                         return status;
547                 }
548         }
549
550         /* And once we are bound, free the tempoary ldb, it will
551          * connect again on each incoming LDAP connection */
552         talloc_unlink(ldap_service, ldb);
553
554         return NT_STATUS_OK;
555 }
556
557 /*
558   open the ldap server sockets
559 */
560 static void ldapsrv_task_init(struct task_server *task)
561 {       
562         char *ldapi_path;
563 #ifdef WITH_LDAPI_PRIV_SOCKET
564         char *priv_dir;
565 #endif
566         struct ldapsrv_service *ldap_service;
567         NTSTATUS status;
568         const struct model_ops *model_ops;
569
570         switch (lp_server_role(task->lp_ctx)) {
571         case ROLE_STANDALONE:
572                 task_server_terminate(task, "ldap_server: no LDAP server required in standalone configuration", 
573                                       false);
574                 return;
575         case ROLE_DOMAIN_MEMBER:
576                 task_server_terminate(task, "ldap_server: no LDAP server required in member server configuration", 
577                                       false);
578                 return;
579         case ROLE_DOMAIN_CONTROLLER:
580                 /* Yes, we want an LDAP server */
581                 break;
582         }
583
584         task_server_set_title(task, "task[ldapsrv]");
585
586         /* run the ldap server as a single process */
587         model_ops = process_model_startup(task->event_ctx, "single");
588         if (!model_ops) goto failed;
589
590         ldap_service = talloc_zero(task, struct ldapsrv_service);
591         if (ldap_service == NULL) goto failed;
592
593         ldap_service->task = task;
594
595         ldap_service->tls_params = tls_initialise(ldap_service, task->lp_ctx);
596         if (ldap_service->tls_params == NULL) goto failed;
597
598         if (lp_interfaces(task->lp_ctx) && lp_bind_interfaces_only(task->lp_ctx)) {
599                 struct interface *ifaces;
600                 int num_interfaces;
601                 int i;
602
603                 load_interfaces(task, lp_interfaces(task->lp_ctx), &ifaces);
604                 num_interfaces = iface_count(ifaces);
605
606                 /* We have been given an interfaces line, and been 
607                    told to only bind to those interfaces. Create a
608                    socket per interface and bind to only these.
609                 */
610                 for(i = 0; i < num_interfaces; i++) {
611                         const char *address = iface_n_ip(ifaces, i);
612                         status = add_socket(task->event_ctx, task->lp_ctx, model_ops, address, ldap_service);
613                         if (!NT_STATUS_IS_OK(status)) goto failed;
614                 }
615         } else {
616                 status = add_socket(task->event_ctx, task->lp_ctx, model_ops, 
617                                     lp_socket_address(task->lp_ctx), ldap_service);
618                 if (!NT_STATUS_IS_OK(status)) goto failed;
619         }
620
621         ldapi_path = private_path(ldap_service, task->lp_ctx, "ldapi");
622         if (!ldapi_path) {
623                 goto failed;
624         }
625
626         status = stream_setup_socket(task->event_ctx, task->lp_ctx,
627                                      model_ops, &ldap_stream_nonpriv_ops,
628                                      "unix", ldapi_path, NULL, 
629                                      lp_socket_options(task->lp_ctx), 
630                                      ldap_service);
631         talloc_free(ldapi_path);
632         if (!NT_STATUS_IS_OK(status)) {
633                 DEBUG(0,("ldapsrv failed to bind to %s - %s\n",
634                          ldapi_path, nt_errstr(status)));
635         }
636
637 #ifdef WITH_LDAPI_PRIV_SOCKET
638         priv_dir = private_path(ldap_service, task->lp_ctx, "ldap_priv");
639         if (priv_dir == NULL) {
640                 goto failed;
641         }
642         /*
643          * Make sure the directory for the privileged ldapi socket exists, and
644          * is of the correct permissions
645          */
646         if (!directory_create_or_exist(priv_dir, geteuid(), 0750)) {
647                 task_server_terminate(task, "Cannot create ldap "
648                                       "privileged ldapi directory", true);
649                 return;
650         }
651         ldapi_path = talloc_asprintf(ldap_service, "%s/ldapi", priv_dir);
652         talloc_free(priv_dir);
653         if (ldapi_path == NULL) {
654                 goto failed;
655         }
656
657         status = stream_setup_socket(task->event_ctx, task->lp_ctx,
658                                      model_ops, &ldap_stream_priv_ops,
659                                      "unix", ldapi_path, NULL,
660                                      lp_socket_options(task->lp_ctx),
661                                      ldap_service);
662         talloc_free(ldapi_path);
663         if (!NT_STATUS_IS_OK(status)) {
664                 DEBUG(0,("ldapsrv failed to bind to %s - %s\n",
665                          ldapi_path, nt_errstr(status)));
666         }
667
668 #endif
669         return;
670
671 failed:
672         task_server_terminate(task, "Failed to startup ldap server task", true);
673 }
674
675
676 NTSTATUS server_service_ldap_init(void)
677 {
678         return register_server_service("ldap", ldapsrv_task_init);
679 }