summaryrefslogtreecommitdiff
path: root/source3/winbindd/idmap_autorid.c
blob: e9048d8484930539ac02a29fbc7494c0752d2966 (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
/*
 *  idmap_autorid: static map between Active Directory/NT RIDs
 *  and RFC 2307 accounts
 *
 *  based on the idmap_rid module, but this module defines the ranges
 *  for the domains by automatically allocating a range for each domain
 *
 *  Copyright (C) Christian Ambach, 2010-2011
 *
 *  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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#include "includes.h"
#include "system/filesys.h"
#include "winbindd.h"
#include "dbwrap.h"
#include "idmap.h"
#include "../libcli/security/dom_sid.h"
#include "util_tdb.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_IDMAP

#define HWM "NEXT RANGE"
#define CONFIGKEY "CONFIG"

struct autorid_global_config {
	uint32_t minvalue;
	uint32_t rangesize;
	uint32_t maxranges;
};

struct autorid_domain_config {
	struct dom_sid sid;
	uint32_t domainnum;
	struct autorid_global_config *globalcfg;
};

/* handle to the tdb storing domain <-> range assignments */
static struct db_context *autorid_db;

static NTSTATUS idmap_autorid_get_domainrange(struct db_context *db,
					      void *private_data)
{
	NTSTATUS ret;
	uint32_t domainnum, hwm;
	fstring sidstr;
	char *numstr;
	struct autorid_domain_config *cfg;

	cfg = (struct autorid_domain_config *)private_data;
	dom_sid_string_buf(&(cfg->sid), sidstr, sizeof(sidstr));

	if (!dbwrap_fetch_uint32(db, sidstr, &domainnum)) {
		DEBUG(10, ("Acquiring new range for domain %s\n", sidstr));

		/* fetch the current HWM */
		if (!dbwrap_fetch_uint32(db, HWM, &hwm)) {
			DEBUG(1, ("Fatal error while fetching current "
				  "HWM value!\n"));
			ret = NT_STATUS_INTERNAL_ERROR;
			goto error;
		}

		/* do we have a range left? */
		if (hwm >= cfg->globalcfg->maxranges) {
			DEBUG(1, ("No more domain ranges available!\n"));
			ret = NT_STATUS_NO_MEMORY;
			goto error;
		}

		/* increase the HWM */
		ret = dbwrap_change_uint32_atomic(db, HWM, &domainnum, 1);
		if (!NT_STATUS_IS_OK(ret)) {
			DEBUG(1, ("Fatal error while fetching a new "
				  "domain range value!\n"));
			goto error;
		}

		/* store away the new mapping in both directions */
		ret = dbwrap_trans_store_uint32(db, sidstr, domainnum);
		if (!NT_STATUS_IS_OK(ret)) {
			DEBUG(1, ("Fatal error while storing new "
				  "domain->range assignment!\n"));
			goto error;
		}

		numstr = talloc_asprintf(db, "%u", domainnum);
		if (!numstr) {
			ret = NT_STATUS_NO_MEMORY;
			goto error;
		}

		ret = dbwrap_trans_store_bystring(db, numstr,
						  string_term_tdb_data(sidstr),
						  TDB_INSERT);
		talloc_free(numstr);
		if (!NT_STATUS_IS_OK(ret)) {
			DEBUG(1, ("Fatal error while storing "
				  "new domain->range assignment!\n"));
			goto error;
		}
		DEBUG(5, ("Acquired new range #%d for domain %s\n",
			  domainnum, sidstr));
	}

	DEBUG(10, ("Using range #%d for domain %s\n", domainnum, sidstr));
	cfg->domainnum = domainnum;

	return NT_STATUS_OK;

      error:
	return ret;

}

static NTSTATUS idmap_autorid_id_to_sid(struct autorid_global_config *cfg,
					struct id_map *map)
{
	uint32_t range;
	TDB_DATA data;
	char *keystr;
	struct dom_sid sid;

	/* can this be one of our ids? */
	if (map->xid.id < cfg->minvalue) {
		DEBUG(10, ("id %d is lower than minimum value, "
			   "ignoring mapping request\n", map->xid.id));
		map->status = ID_UNKNOWN;
		return NT_STATUS_OK;
	}

	if (map->xid.id > (cfg->minvalue + cfg->rangesize * cfg->maxranges)) {
		DEBUG(10, ("id %d is outside of maximum id value, "
			   "ignoring mapping request\n", map->xid.id));
		map->status = ID_UNKNOWN;
		return NT_STATUS_OK;
	}

	/* determine the range of this uid */
	range = ((map->xid.id - cfg->minvalue) / cfg->rangesize);

	keystr = talloc_asprintf(talloc_tos(), "%u", range);
	if (!keystr) {
		return NT_STATUS_NO_MEMORY;
	}

	data = dbwrap_fetch_bystring(autorid_db, talloc_tos(), keystr);
	TALLOC_FREE(keystr);

	if (!data.dptr) {
		DEBUG(4, ("id %d belongs to range %d which does not have "
			  "domain mapping, ignoring mapping request\n",
			  map->xid.id, range));
		map->status = ID_UNKNOWN;
		return NT_STATUS_OK;
	}

	string_to_sid(&sid, (const char *)data.dptr);
	TALLOC_FREE(data.dptr);

	sid_compose(map->sid, &sid,
		    (map->xid.id - cfg->minvalue -
		     range * cfg->rangesize));

	/* We **really** should have some way of validating
	   the SID exists and is the correct type here.  But
	   that is a deficiency in the idmap_rid design. */

	map->status = ID_MAPPED;
	return NT_STATUS_OK;
}

/**********************************
 Single sid to id lookup function.
**********************************/

static NTSTATUS idmap_autorid_sid_to_id(struct autorid_global_config *global,
					struct autorid_domain_config *domain,
					struct id_map *map)
{
	uint32_t rid;

	sid_peek_rid(map->sid, &rid);

	/* if the rid is higher than the size of the range, we cannot map it */
	if (rid >= global->rangesize) {
		map->status = ID_UNKNOWN;
		DEBUG(2, ("RID %d is larger then size of range (%d), "
			  "user cannot be mapped\n", rid, global->rangesize));
		return NT_STATUS_UNSUCCESSFUL;
	}
	map->xid.id = global->minvalue +
	    (global->rangesize * domain->domainnum)+rid;

	/* We **really** should have some way of validating
	   the SID exists and is the correct type here.  But
	   that is a deficiency in the idmap_rid design. */

	map->status = ID_MAPPED;

	return NT_STATUS_OK;
}

/**********************************
 lookup a set of unix ids.
**********************************/

static NTSTATUS idmap_autorid_unixids_to_sids(struct idmap_domain *dom,
					      struct id_map **ids)
{
	struct autorid_global_config *globalcfg;
	NTSTATUS ret;
	int i;

	/* initialize the status to avoid surprise */
	for (i = 0; ids[i]; i++) {
		ids[i]->status = ID_UNKNOWN;
	}

	globalcfg = talloc_get_type(dom->private_data,
				    struct autorid_global_config);

	for (i = 0; ids[i]; i++) {

		ret = idmap_autorid_id_to_sid(globalcfg, ids[i]);

		if ((!NT_STATUS_IS_OK(ret)) &&
		    (!NT_STATUS_EQUAL(ret, NT_STATUS_NONE_MAPPED))) {
			/* some fatal error occurred, log it */
			DEBUG(3, ("Unexpected error resolving an ID "
				  " (%d)\n", ids[i]->xid.id));
			goto failure;
		}
	}
	return NT_STATUS_OK;

      failure:
	return ret;
}

/**********************************
 lookup a set of sids.
**********************************/

static NTSTATUS idmap_autorid_sids_to_unixids(struct idmap_domain *dom,
					      struct id_map **ids)
{
	struct autorid_global_config *global;
	NTSTATUS ret;
	int i;

	/* initialize the status to avoid surprise */
	for (i = 0; ids[i]; i++) {
		ids[i]->status = ID_UNKNOWN;
	}

	global = talloc_get_type(dom->private_data,
				 struct autorid_global_config);

	for (i = 0; ids[i]; i++) {
		struct winbindd_tdc_domain *domain;
		struct autorid_domain_config domaincfg;
		uint32_t rid;

		ZERO_STRUCT(domaincfg);

		sid_copy(&domaincfg.sid, ids[i]->sid);
		if (!sid_split_rid(&domaincfg.sid, &rid)) {
			DEBUG(4, ("Could not determine domain SID from %s, "
				  "ignoring mapping request\n",
				  sid_string_dbg(ids[i]->sid)));
			continue;
		}

		/*
		 * Check if the domain is around
		 */
		domain = wcache_tdc_fetch_domainbysid(talloc_tos(),
						      &domaincfg.sid);
		if (domain == NULL) {
			DEBUG(10, ("Ignoring unknown domain sid %s\n",
				   sid_string_dbg(&domaincfg.sid)));
			continue;
		}
		TALLOC_FREE(domain);

		domaincfg.globalcfg = global;

		ret = dbwrap_trans_do(autorid_db,
				      idmap_autorid_get_domainrange,
				      &domaincfg);

		if (!NT_STATUS_IS_OK(ret)) {
			DEBUG(3, ("Could not determine range for domain, "
				  "check previous messages for reason\n"));
			goto failure;
		}

		ret = idmap_autorid_sid_to_id(global, &domaincfg, ids[i]);

		if ((!NT_STATUS_IS_OK(ret)) &&
		    (!NT_STATUS_EQUAL(ret, NT_STATUS_NONE_MAPPED))) {
			/* some fatal error occurred, log it */
			DEBUG(3, ("Unexpected error resolving a SID (%s)\n",
				  sid_string_dbg(ids[i]->sid)));
			goto failure;
		}
	}
	return NT_STATUS_OK;

      failure:
	return ret;

}

/*
 * open and initialize the database which stores the ranges for the domains
 */
static NTSTATUS idmap_autorid_db_init(void)
{
	int32_t hwm;

	if (autorid_db) {
		/* its already open */
		return NT_STATUS_OK;
	}

	/* Open idmap repository */
	autorid_db = db_open(NULL, state_path("autorid.tdb"), 0,
			     TDB_DEFAULT, O_RDWR | O_CREAT, 0644);

	if (!autorid_db) {
		DEBUG(0, ("Unable to open idmap_autorid database '%s'\n",
			  state_path("autorid.tdb")));
		return NT_STATUS_UNSUCCESSFUL;
	}

	/* Initialize high water mark for the currently used range to 0 */
	hwm = dbwrap_fetch_int32(autorid_db, HWM);
	if ((hwm < 0)) {
		if (!NT_STATUS_IS_OK
		    (dbwrap_trans_store_int32(autorid_db, HWM, 0))) {
			DEBUG(0,
			      ("Unable to initialise HWM in autorid "
			       "database\n"));
			return NT_STATUS_INTERNAL_DB_ERROR;
		}
	}

	return NT_STATUS_OK;
}

static struct autorid_global_config *idmap_autorid_loadconfig(TALLOC_CTX * ctx)
{

	TDB_DATA data;
	struct autorid_global_config *cfg;
	unsigned long minvalue, rangesize, maxranges;

	data = dbwrap_fetch_bystring(autorid_db, ctx, CONFIGKEY);

	if (!data.dptr) {
		DEBUG(10, ("No saved config found\n"));
		return NULL;
	}

	cfg = talloc_zero(ctx, struct autorid_global_config);
	if (!cfg) {
		return NULL;
	}

	if (sscanf((char *)data.dptr,
		   "minvalue:%lu rangesize:%lu maxranges:%lu",
		   &minvalue, &rangesize, &maxranges) != 3) {
		DEBUG(1,
		      ("Found invalid configuration data"
		       "creating new config\n"));
		return NULL;
	}

	cfg->minvalue = minvalue;
	cfg->rangesize = rangesize;
	cfg->maxranges = maxranges;

	DEBUG(10, ("Loaded previously stored configuration "
		   "minvalue:%d rangesize:%d\n",
		   cfg->minvalue, cfg->rangesize));

	return cfg;

}

static NTSTATUS idmap_autorid_saveconfig(struct autorid_global_config *cfg)
{

	NTSTATUS status;
	TDB_DATA data;
	char *cfgstr;

	cfgstr =
	    talloc_asprintf(talloc_tos(),
			    "minvalue:%u rangesize:%u maxranges:%u",
			    cfg->minvalue, cfg->rangesize, cfg->maxranges);

	if (!cfgstr) {
		return NT_STATUS_NO_MEMORY;
	}

	data = string_tdb_data(cfgstr);

	status = dbwrap_trans_store_bystring(autorid_db, CONFIGKEY,
					     data, TDB_REPLACE);

	talloc_free(cfgstr);

	return status;
}

static NTSTATUS idmap_autorid_initialize(struct idmap_domain *dom)
{
	struct autorid_global_config *config;
	struct autorid_global_config *storedconfig = NULL;
	NTSTATUS status;
	uint32_t hwm;

	config = talloc_zero(dom, struct autorid_global_config);
	if (!config) {
		DEBUG(0, ("Out of memory!\n"));
		return NT_STATUS_NO_MEMORY;
	}

	status = idmap_autorid_db_init();
	if (!NT_STATUS_IS_OK(status)) {
		goto error;
	}

	config->minvalue = dom->low_id;
	config->rangesize = lp_parm_int(-1, "autorid", "rangesize", 100000);

	if (config->rangesize < 2000) {
		DEBUG(1, ("autorid rangesize must be at least 2000\n"));
		status = NT_STATUS_INVALID_PARAMETER;
		goto error;
	}

	config->maxranges = (dom->high_id - dom->low_id + 1) /
	    config->rangesize;

	if (config->maxranges == 0) {
		DEBUG(1, ("allowed uid range is smaller then rangesize, "
			  "increase uid range or decrease rangesize\n"));
		status = NT_STATUS_INVALID_PARAMETER;
		goto error;
	}

	/* check if the high-low limit is a multiple of the rangesize */
	if ((dom->high_id - dom->low_id + 1) % config->rangesize != 0) {
		DEBUG(5, ("High uid-low uid difference of %d "
			  "is not a multiple of the rangesize %d, "
			  "limiting ranges to lower boundary number of %d\n",
			  (dom->high_id - dom->low_id + 1), config->rangesize,
			  config->maxranges));
	}

	DEBUG(10, ("Current configuration in config is "
		   "minvalue:%d rangesize:%d maxranges:%d\n",
		   config->minvalue, config->rangesize, config->maxranges));

	/* read previously stored config and current HWM */
	storedconfig = idmap_autorid_loadconfig(talloc_tos());

	if (!dbwrap_fetch_uint32(autorid_db, HWM, &hwm)) {
		DEBUG(1, ("Fatal error while fetching current "
			  "HWM value!\n"));
		status = NT_STATUS_INTERNAL_ERROR;
		goto error;
	}

	/* did the minimum value or rangesize change? */
	if (storedconfig &&
	    ((storedconfig->minvalue != config->minvalue) ||
	     (storedconfig->rangesize != config->rangesize))) {
		DEBUG(1, ("New configuration values for rangesize or "
			  "minimum uid value conflict with previously "
			  "used values! Aborting initialization\n"));
		status = NT_STATUS_INVALID_PARAMETER;
		goto error;
	}

	/*
	 * has the highest uid value been reduced to setting that is not
	 * sufficient any more for already existing ranges?
	 */
	if (hwm > config->maxranges) {
		DEBUG(1, ("New upper uid limit is too low to cover "
			  "existing mappings! Aborting initialization\n"));
		status = NT_STATUS_INVALID_PARAMETER;
		goto error;
	}

	status = idmap_autorid_saveconfig(config);

	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to store configuration data!\n"));
		goto error;
	}

	DEBUG(5, ("%d domain ranges with a size of %d are available\n",
		  config->maxranges, config->rangesize));

	dom->private_data = config;

	if (!NT_STATUS_IS_OK(status)) {
		goto error;
	}

	return NT_STATUS_OK;

      error:
	talloc_free(config);
	talloc_free(storedconfig);

	return status;
}

/*
  Close the idmap tdb instance
*/
static struct idmap_methods autorid_methods = {
	.init = idmap_autorid_initialize,
	.unixids_to_sids = idmap_autorid_unixids_to_sids,
	.sids_to_unixids = idmap_autorid_sids_to_unixids,
};

NTSTATUS idmap_autorid_init(void)
{
	return smb_register_idmap(SMB_IDMAP_INTERFACE_VERSION,
				  "autorid", &autorid_methods);
}