summaryrefslogtreecommitdiff
path: root/source3/sam/idmap_ldap.c
blob: 33cf5fb03026d5c81991ae93b0c1a6fd62a995ba (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
/* 
   Unix SMB/CIFS implementation.

   idmap LDAP backend

   Copyright (C) Tim Potter 2000
   Copyright (C) Anthony Liguori 2003
   Copyright (C) Simo Sorce 2003
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_IDMAP


#include <lber.h>
#include <ldap.h>

struct ldap_idmap_state {
	LDAP *ldap_struct;
	time_t last_ping;
	const char *uri;
	char *bind_dn;
	char *bind_secret;
	unsigned int num_failures;
	struct ldap_idmap_state *prev, *next;
};

#define LDAP_IDMAP_DONT_PING_TIME 10       /* ping only all 10 seconds */
#define LDAP_MAX_ALLOC_ID 128              /* number tries while allocating
					      new id */

static struct ldap_idmap_state ldap_state;

static int ldap_idmap_connect_system(struct ldap_idmap_state *state);
static NTSTATUS ldap_set_mapping(const DOM_SID *sid, unid_t id, int id_type);
static NTSTATUS ldap_idmap_close(void);


/*******************************************************************
 find the ldap password
******************************************************************/
static BOOL fetch_ldapsam_pw(char **dn, char** pw)
{
	char *key = NULL;
	size_t size;
	
	*dn = smb_xstrdup(lp_ldap_admin_dn());
	
	if (asprintf(&key, "%s/%s", SECRETS_LDAP_BIND_PW, *dn) < 0) {
		SAFE_FREE(*dn);
		DEBUG(0, ("fetch_ldapsam_pw: asprintf failed!\n"));
	}
	
	*pw=secrets_fetch(key, &size);
	SAFE_FREE(key);

	if (!size) {
		/* Upgrade 2.2 style entry */
		char *p;
	        char* old_style_key = strdup(*dn);
		char *data;
		fstring old_style_pw;
		
		if (!old_style_key) {
			DEBUG(0, ("fetch_ldapsam_pw: strdup failed!\n"));
			return False;
		}

		for (p=old_style_key; *p; p++)
			if (*p == ',') *p = '/';
	
		data=secrets_fetch(old_style_key, &size);
		if (!size && size < sizeof(old_style_pw)) {
			DEBUG(0,("fetch_ldap_pw: neither ldap secret retrieved!\n"));
			SAFE_FREE(old_style_key);
			SAFE_FREE(*dn);
			return False;
		}

		strncpy(old_style_pw, data, size);
		old_style_pw[size] = 0;

		SAFE_FREE(data);

		if (!secrets_store_ldap_pw(*dn, old_style_pw)) {
			DEBUG(0,("fetch_ldap_pw: ldap secret could not be upgraded!\n"));
			SAFE_FREE(old_style_key);
			SAFE_FREE(*dn);
			return False;			
		}
		if (!secrets_delete(old_style_key)) {
			DEBUG(0,("fetch_ldap_pw: old ldap secret could not be deleted!\n"));
		}

		SAFE_FREE(old_style_key);

		*pw = smb_xstrdup(old_style_pw);		
	}
	
	return True;
}

/*******************************************************************
 open a connection to the ldap server.
******************************************************************/
static int ldap_idmap_open_connection(struct ldap_idmap_state *state)
{
	int rc = LDAP_SUCCESS;
	int version;
	BOOL ldap_v3 = False;

#ifdef HAVE_LDAP_INITIALIZE
	DEBUG(10, ("ldap_idmap_open_connection: %s\n", state->uri));
	
	if ((rc = ldap_initialize(&state->ldap_struct, state->uri)) 
	    != LDAP_SUCCESS) {
		DEBUG(0, ("ldap_initialize: %s\n", ldap_err2string(rc)));
		return rc;
	}
#else 
	/* Parse the string manually */
	{
		int port = 0;
		fstring protocol;
		fstring host;
		const char *p = state->uri; 
		SMB_ASSERT(sizeof(protocol)>10 && sizeof(host)>254);
		
		/* skip leading "URL:" (if any) */
		if ( strncasecmp( p, "URL:", 4 ) == 0 ) {
			p += 4;
		}
		
		sscanf(p, "%10[^:]://%254s[^:]:%d", protocol, host, &port);
		
		if (port == 0) {
			if (strequal(protocol, "ldap")) {
				port = LDAP_PORT;
			} else if (strequal(protocol, "ldaps")) {
				port = LDAPS_PORT;
			} else {
				DEBUG(0, ("unrecognised protocol (%s)!\n",
					  protocol));
			}
		}
		
		if ((state->ldap_struct = ldap_init(host, port)) == NULL) {
			DEBUG(0, ("ldap_init failed !\n"));
			return LDAP_OPERATIONS_ERROR;
		}
		
	        if (strequal(protocol, "ldaps")) {
#ifdef LDAP_OPT_X_TLS
			int tls = LDAP_OPT_X_TLS_HARD;
			if (ldap_set_option (state->ldap_struct, 
					     LDAP_OPT_X_TLS, &tls) != 
			    LDAP_SUCCESS)
			{
				DEBUG(0, ("Failed to setup a TLS session\n"));
			}
			
			DEBUG(3,("LDAPS option set...!\n"));
#else
			DEBUG(0,("ldap_idmap_open_connection: Secure "
				 "connection not supported by LDAP client "
				 "libraries!\n"));
			return LDAP_OPERATIONS_ERROR;
#endif
		}
	}
#endif

	if (ldap_get_option(state->ldap_struct, LDAP_OPT_PROTOCOL_VERSION,
			    &version) == LDAP_OPT_SUCCESS) {
		if (version != LDAP_VERSION3) {
			version = LDAP_VERSION3;
			if (ldap_set_option(state->ldap_struct,
					    LDAP_OPT_PROTOCOL_VERSION,
					    &version) == LDAP_OPT_SUCCESS) {
				ldap_v3 = True;
			}
		} else {
			ldap_v3 = True;
		}
	}

	if (lp_ldap_ssl() == LDAP_SSL_START_TLS) {
#ifdef LDAP_OPT_X_TLS
		if (ldap_v3) {
			if ((rc = ldap_start_tls_s(state->ldap_struct, NULL,
						   NULL)) != LDAP_SUCCESS) {
				DEBUG(0,("Failed to issue the StartTLS "
					 "instruction: %s\n",
					 ldap_err2string(rc)));
				return rc;
			}
			DEBUG (3, ("StartTLS issued: using a TLS "
				   "connection\n"));
		} else {
			
			DEBUG(0, ("Need LDAPv3 for Start TLS\n"));
			return LDAP_OPERATIONS_ERROR;
		}
#else
		DEBUG(0,("ldap_idmap_open_connection: StartTLS not supported by "
			 "LDAP client libraries!\n"));
		return LDAP_OPERATIONS_ERROR;
#endif
	}

	DEBUG(2, ("ldap_idmap_open_connection: connection opened\n"));
	return rc;
}

/**********************************************************************
Connect to LDAP server 
*********************************************************************/
static int ldap_idmap_open(struct ldap_idmap_state *state)
{
	int rc;
	SMB_ASSERT(state);
		
#ifndef NO_LDAP_SECURITY
	if (geteuid() != 0) {
		DEBUG(0, 
		      ("ldap_idmap_open: cannot access LDAP when not root\n"));
		return  LDAP_INSUFFICIENT_ACCESS;
	}
#endif

	if ((state->ldap_struct != NULL) && 
	    ((state->last_ping + LDAP_IDMAP_DONT_PING_TIME)<time(NULL))) {
		struct sockaddr_un addr;
		socklen_t len = sizeof(addr);
		int sd;

		if (!ldap_get_option(state->ldap_struct,  LDAP_OPT_DESC, &sd)&&
		    getpeername(sd, (struct sockaddr *) &addr, &len) < 0) {
		    	/* the other end has died. reopen. */
		    	ldap_unbind_ext(state->ldap_struct, NULL, NULL);
		    	state->ldap_struct = NULL;
		    	state->last_ping = (time_t)0;
		} else {
			state->last_ping = time(NULL);
		} 
    	}

	if (state->ldap_struct != NULL) {
		DEBUG(5,("ldap_idmap_open: already connected to the LDAP "
			 "server\n"));
		return LDAP_SUCCESS;
	}

	if ((rc = ldap_idmap_open_connection(state))) {
		return rc;
	}

	if ((rc = ldap_idmap_connect_system(state))) {
		ldap_unbind_ext(state->ldap_struct, NULL, NULL);
		state->ldap_struct = NULL;
		return rc;
	}


	state->last_ping = time(NULL);
	DEBUG(4,("The LDAP server is succesful connected\n"));

	return LDAP_SUCCESS;
}

static int ldap_idmap_retry_open(struct ldap_idmap_state *state, int *attempts)
{
	int rc;

	SMB_ASSERT(state && attempts);

	if (*attempts != 0) {
		unsigned int sleep_time;
		uint8 rand_byte = 128; /* a reasonable place to start */

		generate_random_buffer(&rand_byte, 1, False);

		sleep_time = (((*attempts)*(*attempts))/2)*rand_byte*2; 
		/* we retry after (0.5, 1, 2, 3, 4.5, 6) seconds
		   on average.  
		 */
		DEBUG(3, ("Sleeping for %u milliseconds before reconnecting\n",
			  sleep_time));
		msleep(sleep_time);
	}
	(*attempts)++;

	if ((rc = ldap_idmap_open(state))) {
		DEBUG(1,("Connection to LDAP Server failed for the %d try!\n",
			 *attempts));
		return rc;
	} 
	
	return LDAP_SUCCESS;		
}

/*******************************************************************
 a rebind function for authenticated referrals
 This version takes a void* that we can shove useful stuff in :-)
******************************************************************/
#if defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)
#else
static int rebindproc_with_state  (LDAP * ld, char **whop, char **credp, 
				   int *methodp, int freeit, void *arg)
{
	struct ldap_idmap_state *state = arg;
	
	/** @TODO Should we be doing something to check what servers we rebind
	    to?  Could we get a referral to a machine that we don't want to
	    give our username and password to? */
	
	if (freeit) {
		SAFE_FREE(*whop);
		memset(*credp, '\0', strlen(*credp));
		SAFE_FREE(*credp);
	} else {
		DEBUG(5,("rebind_proc_with_state: Rebinding as \"%s\"\n", 
			  state->bind_dn));

		*whop = strdup(state->bind_dn);
		if (!*whop) {
			return LDAP_NO_MEMORY;
		}
		*credp = strdup(state->bind_secret);
		if (!*credp) {
			SAFE_FREE(*whop);
			return LDAP_NO_MEMORY;
		}
		*methodp = LDAP_AUTH_SIMPLE;
	}
	return 0;
}
#endif /*defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)*/

/*******************************************************************
 a rebind function for authenticated referrals
 This version takes a void* that we can shove useful stuff in :-)
 and actually does the connection.
******************************************************************/
#if defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)
static int rebindproc_connect_with_state (LDAP *ldap_struct, 
					  LDAP_CONST char *url, 
					  ber_tag_t request,
					  ber_int_t msgid, void *arg)
{
	struct ldap_idmap_state *state = arg;
	int rc;
	DEBUG(5,("rebindproc_connect_with_state: Rebinding as \"%s\"\n", 
		 state->bind_dn));
	
	/** @TODO Should we be doing something to check what servers we rebind
	    to?  Could we get a referral to a machine that we don't want to
	    give our username and password to? */

	rc = ldap_simple_bind_s(ldap_struct, state->bind_dn, 
				state->bind_secret);
	
	return rc;
}
#endif /*defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)*/

/*******************************************************************
 Add a rebind function for authenticated referrals
******************************************************************/
#if defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)
#else
# if LDAP_SET_REBIND_PROC_ARGS == 2
static int rebindproc (LDAP *ldap_struct, char **whop, char **credp,
		       int *method, int freeit )
{
	return rebindproc_with_state(ldap_struct, whop, credp,
				   method, freeit, &ldap_state);
	
}
# endif /*LDAP_SET_REBIND_PROC_ARGS == 2*/
#endif /*defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)*/

/*******************************************************************
 a rebind function for authenticated referrals
 this also does the connection, but no void*.
******************************************************************/
#if defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)
# if LDAP_SET_REBIND_PROC_ARGS == 2
static int rebindproc_connect (LDAP * ld, LDAP_CONST char *url, int request,
			       ber_int_t msgid)
{
	return rebindproc_connect_with_state(ld, url, (ber_tag_t)request,
					     msgid, &ldap_state);
}
# endif /*LDAP_SET_REBIND_PROC_ARGS == 2*/
#endif /*defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)*/

/*******************************************************************
 connect to the ldap server under system privilege.
******************************************************************/
static int ldap_idmap_connect_system(struct ldap_idmap_state *state)
{
	int rc;
	char *ldap_dn;
	char *ldap_secret;

	/* get the password */
	if (!fetch_ldapsam_pw(&ldap_dn, &ldap_secret))
	{
		DEBUG(0, ("ldap_idmap_connect_system: Failed to retrieve "
			  "password from secrets.tdb\n"));
		return LDAP_INVALID_CREDENTIALS;
	}

	state->bind_dn = ldap_dn;
	state->bind_secret = ldap_secret;

	/* removed the sasl_bind_s "EXTERNAL" stuff, as my testsuite 
	   (OpenLDAP) doesnt' seem to support it */
	   
	DEBUG(10,("ldap_idmap_connect_system: Binding to ldap server %s as "
		  "\"%s\"\n", state->uri, ldap_dn));

#if defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)
# if LDAP_SET_REBIND_PROC_ARGS == 2	
	ldap_set_rebind_proc(state->ldap_struct, &rebindproc_connect);	
# endif
# if LDAP_SET_REBIND_PROC_ARGS == 3	
	ldap_set_rebind_proc(state->ldap_struct, 
			     &rebindproc_connect_with_state, (void *)state);
# endif
#else /*defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)*/
# if LDAP_SET_REBIND_PROC_ARGS == 2	
	ldap_set_rebind_proc(state->ldap_struct, &rebindproc);	
# endif
# if LDAP_SET_REBIND_PROC_ARGS == 3	
	ldap_set_rebind_proc(state->ldap_struct, &rebindproc_with_state,
			     (void *)state);	
# endif
#endif /*defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)*/

	rc = ldap_simple_bind_s(state->ldap_struct, ldap_dn, ldap_secret);

	if (rc != LDAP_SUCCESS) {
		char *ld_error = NULL;
		ldap_get_option(state->ldap_struct, LDAP_OPT_ERROR_STRING,
				&ld_error);
		DEBUG(state->num_failures ? 2 : 0,
		      ("failed to bind to server with dn= %s Error: "
		       "%s\n\t%s\n",
		       ldap_dn ? ld_error : "(unknown)",
		       ldap_err2string(rc), ld_error));
		SAFE_FREE(ld_error);
		state->num_failures++;
		return rc;
	}

	state->num_failures = 0;

	DEBUG(3, ("ldap_idmap_connect_system: succesful connection to the "
		  "LDAP server\n"));
	return rc;
}

static int ldap_idmap_search(struct ldap_idmap_state *state, 
			     const char *base, int scope, const char *filter, 
			     const char *attrs[], int attrsonly, 
			     LDAPMessage **res)
{
	int rc = LDAP_SERVER_DOWN;
	int attempts = 0;
	char *utf8_filter;

	SMB_ASSERT(state);

	if (push_utf8_allocate(&utf8_filter, filter) == (size_t)-1) {
		return LDAP_NO_MEMORY;
	}

	while ((rc == LDAP_SERVER_DOWN) && (attempts < 8)) {
		if ((rc = ldap_idmap_retry_open(state, &attempts)) !=
		    LDAP_SUCCESS) continue;
		
		rc = ldap_search_s(state->ldap_struct, base, scope, 
				   utf8_filter, (char**)attrs, attrsonly, res);
	}
	
	if (rc == LDAP_SERVER_DOWN) {
		DEBUG(0,("ldap_idmap_search: LDAP server is down!\n"));
		ldap_idmap_close();
	}

	SAFE_FREE(utf8_filter);
	return rc;
}

/*******************************************************************
search an attribute and return the first value found.
******************************************************************/
static BOOL ldap_idmap_attribute (struct ldap_idmap_state *state,
				  LDAPMessage * entry,
				  const char *attribute, pstring value)
{
	char **values;
	value[0] = '\0';

	if ((values = ldap_get_values (state->ldap_struct, entry, attribute))
	    == NULL) {
		DEBUG(10,("get_single_attribute: [%s] = [<does not exist>]\n",
			  attribute));
		return False;
	}
	if (convert_string(CH_UTF8, CH_UNIX,
		values[0], -1,
		value, sizeof(pstring)) == (size_t)-1)
	{
		DEBUG(1, ("ldap_idmap_attribute: string conversion of [%s] = "
			  "[%s] failed!\n",  attribute, values[0]));
		ldap_value_free(values);
		return False;
	}
	ldap_value_free(values);

	return True;
}

static const char *attrs[] = {"objectClass", "uidNumber", "gidNumber", 
			      "ntSid", NULL};
static const char *pool_attr[] = {"uidNumber", "gidNumber", NULL};

static NTSTATUS ldap_allocate_id(unid_t *id, int id_type)
{
	NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
	int rc = LDAP_SERVER_DOWN;
	int count = 0;
	LDAPMessage *result = 0;
	LDAPMessage *entry = 0;
	pstring id_str, new_id_str;
	LDAPMod mod[2];
	LDAPMod *mods[3];
	const char *type = (id_type & ID_USERID) ? "uidNumber" : "gidNumber";
	char *val[4];
	char *dn;

	rc = ldap_idmap_search(&ldap_state, lp_ldap_suffix(),
			       LDAP_SCOPE_SUBTREE, "(objectClass=unixIdPool)",
			       pool_attr, 0, &result);
	if (rc != LDAP_SUCCESS) {
		DEBUG(0,("ldap_allocate_id: unixIdPool object not found\n"));
		goto out;
	}
	
	count = ldap_count_entries(ldap_state.ldap_struct, result);
	if (count != 1) {
		DEBUG(0,("ldap_allocate_id: single unixIdPool not found\n"));
		goto out;
	}

	dn = ldap_get_dn(ldap_state.ldap_struct, result);
	entry = ldap_first_entry(ldap_state.ldap_struct, result);

	if (!ldap_idmap_attribute(&ldap_state, entry, type, id_str)) {
		DEBUG(0,("ldap_allocate_id: %s attribute not found\n",
			 type));
		goto out;
	}
	if (id_type & ID_USERID) {
		id->uid = strtoul(id_str, NULL, 10);
	} else {
		id->gid = strtoul(id_str, NULL, 10);
	}

	mod[0].mod_op = LDAP_MOD_DELETE;
	mod[0].mod_type = strdup(type);
	val[0] = id_str; val[1] = NULL;
	mod[0].mod_values = val;

	pstr_sprintf(new_id_str, "%ud", 
		 ((id_type & ID_USERID) ? id->uid : id->gid) + 1);
	mod[1].mod_op = LDAP_MOD_ADD;
	mod[1].mod_type = strdup(type);
	val[3] = new_id_str; val[4] = NULL;
	mod[1].mod_values = val + 2;

	mods[0] = mod; mods[1] = mod + 1; mods[2] = NULL;
	rc = ldap_modify_s(ldap_state.ldap_struct, dn, mods);
	ldap_memfree(dn);

	if (rc == LDAP_SUCCESS) ret = NT_STATUS_OK;
out:
	return ret;
}

/* Get a sid from an id */
static NTSTATUS ldap_get_sid_from_id(DOM_SID *sid, unid_t id, int id_type)
{
	LDAPMessage *result = 0;
	LDAPMessage *entry = 0;
	pstring sid_str;
	pstring filter;
	char type = (id_type & ID_USERID) ? 'u' : 'g';
	int rc;
	int count;
	NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
	   
	pstr_sprintf(filter, "(&(%cidNumber=%ud)(objectClass=sambaAccount))",
		 type, ((id_type & ID_USERID) ? id.uid : id.gid));
	rc = ldap_idmap_search(&ldap_state, lp_ldap_suffix(), 
			       LDAP_SCOPE_SUBTREE, filter, attrs, 0, 
			       &result);
	if (rc != LDAP_SUCCESS) {
		goto out;
	}
	
	count = ldap_count_entries(ldap_state.ldap_struct, result);
	if (count == 0) {
		   pstr_sprintf(filter,
			    "(&(objectClass=idmapEntry)(%cidNumber=%ud))",
			    type, ((id_type & ID_USERID) ? id.uid : id.gid));
		   rc = ldap_idmap_search(&ldap_state, lp_ldap_suffix(),
					  LDAP_SCOPE_SUBTREE, filter,
					  attrs, 0, &result);
		   if (rc != LDAP_SUCCESS) {
			   goto out;
		   }
		   count = ldap_count_entries(ldap_state.ldap_struct, result);
	}
	
	if (count != 1) {
		DEBUG(0,("ldap_get_sid_from_id: mapping not found for "
			 "%cid: %ud\n", (id_type&ID_USERID)?'u':'g',
			 ((id_type & ID_USERID) ? id.uid : id.gid)));
		goto out;
	}
	
	entry = ldap_first_entry(ldap_state.ldap_struct, result);
	
	if (!ldap_idmap_attribute(&ldap_state, entry, "ntSid", sid_str)) {
		goto out;
	}
	   
	if (!string_to_sid(sid, sid_str)) {
		goto out;
	}

	ret = NT_STATUS_OK;
out:
	return ret;
}

/* Get an id from a sid */
static NTSTATUS ldap_get_id_from_sid(unid_t *id, int *id_type,
				     const DOM_SID *sid)
{
	LDAPMessage *result = 0;
	LDAPMessage *entry = 0;
	pstring sid_str;
	pstring filter;
	pstring id_str;
	const char *type = (*id_type & ID_USERID) ? "uidNumber" : "gidNumber";
	const char *class =
		(*id_type & ID_USERID) ? "sambaAccount" : "sambaGroupMapping";
	int rc;
	int count;
	NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
	   
	sid_to_string(sid_str, sid);
	pstr_sprintf(filter, "(&(objectClass=%s)(ntSid=%s)", class, sid_str);
	rc = ldap_idmap_search(&ldap_state, lp_ldap_suffix(), 
			       LDAP_SCOPE_SUBTREE, filter, attrs, 0, &result);
	if (rc != LDAP_SUCCESS) {
		goto out;
	}
	count = ldap_count_entries(ldap_state.ldap_struct, result);
	if (count == 0) {
		   pstr_sprintf(filter,
			    "(&(objectClass=idmapEntry)(ntSid=%s))", sid_str);

		   rc = ldap_idmap_search(&ldap_state, lp_ldap_suffix(),
					  LDAP_SCOPE_SUBTREE, filter,
					  attrs, 0, &result);
		   if (rc != LDAP_SUCCESS) {
			   goto out;
		   }
		   count = ldap_count_entries(ldap_state.ldap_struct, result);
	}

	/* our search filters may 2 objects in the case that a user and group
	   rid are the same */
	if (count != 1 && count != 2) {
		DEBUG(0,
		      ("ldap_get_id_from_sid: incorrect number of objects\n"));
		goto out;
	}

	entry = ldap_first_entry(ldap_state.ldap_struct, result);
	if (!ldap_idmap_attribute(&ldap_state, entry, type, id_str)) {
		entry = ldap_next_entry(ldap_state.ldap_struct, entry);

		if (!ldap_idmap_attribute(&ldap_state, entry, type, id_str)) {
			int i;

			for (i = 0; i < LDAP_MAX_ALLOC_ID; i++) {
				ret = ldap_allocate_id(id, *id_type);
				if (NT_STATUS_IS_OK(ret)) {
					break;
				}
			}
			if (NT_STATUS_IS_OK(ret)) {
				ret = ldap_set_mapping(sid, *id, *id_type);
			} else {
				DEBUG(0,("ldap_allocate_id: cannot acquire id"
					 " lock\n"));
			}
		} else {
			if ((*id_type & ID_USERID)) {
				id->uid = strtoul(id_str, NULL, 10);
			} else {
				id->gid = strtoul(id_str, NULL, 10);
			}
			ret = NT_STATUS_OK;
		}
	} else {
		if ((*id_type & ID_USERID)) {
			id->uid = strtoul(id_str, NULL, 10);
		} else {
			id->gid = strtoul(id_str, NULL, 10);
		}
		ret = NT_STATUS_OK;
	}
out:
	return ret;
}

/* This function cannot be called to modify a mapping, only set a new one */
static NTSTATUS ldap_set_mapping(const DOM_SID *sid, unid_t id, int id_type)
{
	pstring dn, sid_str, id_str;
	const char *type = (id_type & ID_USERID) ? "uidNumber" : "gidNumber";
	LDAPMod *mods[3];
	LDAPMod mod[2];
	char *val[4];
	int rc;
	int attempts = 0;

	pstr_sprintf(id_str, "%ud", ((id_type & ID_USERID) ? id.uid : id.gid));
	sid_to_string(sid_str, sid);
	pstr_sprintf(dn, "%s=%ud,%s", type, ((id_type & ID_USERID) ? id.uid : id.gid), lp_ldap_suffix());
	mod[0].mod_op = LDAP_MOD_REPLACE;
	mod[0].mod_type = strdup(type);
	val[0] = id_str; val[1] = NULL;
	mod[0].mod_values = val;

	mod[1].mod_op = LDAP_MOD_REPLACE;
	mod[1].mod_type = strdup("ntSid");
	val[2] = sid_str; val[3] = NULL;
	mod[1].mod_values = val + 2;

	mods[0] = mod; mods[1] = mod + 1; mods[2] = NULL;

	do {
		if ((rc = ldap_idmap_retry_open(&ldap_state, &attempts)) !=
		    LDAP_SUCCESS) continue;
		
		rc = ldap_modify_s(ldap_state.ldap_struct, dn, mods);
	} while ((rc == LDAP_SERVER_DOWN) && (attempts <= 8));

	if (rc != LDAP_SUCCESS) {
		return NT_STATUS_UNSUCCESSFUL;
	}

	return NT_STATUS_OK;
}

/*****************************************************************************
 Initialise idmap database. 
*****************************************************************************/
static NTSTATUS ldap_idmap_init(void)
{
	/* We wait for the first search request before we try to connect to
	   the LDAP server.  We may want to connect upon initialization though
	   -- aliguori */
	return NT_STATUS_OK;
}

/* End the LDAP session */
static NTSTATUS ldap_idmap_close(void)
{
	if (ldap_state.ldap_struct != NULL) {
		ldap_unbind_ext(ldap_state.ldap_struct, NULL, NULL);
		ldap_state.ldap_struct = NULL;
	}
	
	DEBUG(5,("The connection to the LDAP server was closed\n"));
	/* maybe free the results here --metze */
	
	return NT_STATUS_OK;
}


/* This function doesn't make as much sense in an LDAP world since the calling
   node doesn't really control the ID ranges */
static void ldap_idmap_status(void)
{
	DEBUG(0, ("LDAP IDMAP Status not available\n"));
}

static struct idmap_methods ldap_methods = {
	ldap_idmap_init,
	ldap_get_sid_from_id,
	ldap_get_id_from_sid,
	ldap_set_mapping,
	ldap_idmap_close,
	ldap_idmap_status

};

NTSTATUS idmap_ldap_init(void)
{
	DEBUG(0,("idmap_reg_ldap: no LDAP support\n"));
	return smb_register_idmap(SMB_IDMAP_INTERFACE_VERSION, "ldap", &ldap_methods);
}