summaryrefslogtreecommitdiff
path: root/lib/ldb-samba/ldb_wrap.c
blob: 7cab98fee979d4bf42b956a6f6f10f0c611c3f5d (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
/*
   Unix SMB/CIFS implementation.

   LDB wrap functions

   Copyright (C) Andrew Tridgell 2004-2009

   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/>.
*/

/*
  the stupidity of the unix fcntl locking design forces us to never
  allow a database file to be opened twice in the same process. These
  wrappers provide convenient access to a tdb or ldb, taking advantage
  of talloc destructors to ensure that only a single open is done
*/

#include "includes.h"
#include "lib/events/events.h"
#include <ldb.h>
#include <ldb_errors.h>
#include "lib/ldb-samba/ldif_handlers.h"
#include "ldb_wrap.h"
#include "dsdb/samdb/samdb.h"
#include "param/param.h"
#include "../lib/util/dlinklist.h"
#include <tdb.h>

#define DBGC_CLASS DBGC_LDB

/*
  this is used to catch debug messages from ldb
*/
static void ldb_wrap_debug(void *context, enum ldb_debug_level level,
			   const char *fmt, va_list ap)  PRINTF_ATTRIBUTE(3,0);

static void ldb_wrap_debug(void *context, enum ldb_debug_level level,
			   const char *fmt, va_list ap)
{
	int samba_level = -1;
	switch (level) {
	case LDB_DEBUG_FATAL:
		samba_level = 0;
		break;
	case LDB_DEBUG_ERROR:
		samba_level = 1;
		break;
	case LDB_DEBUG_WARNING:
		samba_level = 2;
		break;
	case LDB_DEBUG_TRACE:
		samba_level = 5;
		break;

	};
	if (CHECK_DEBUGLVL(samba_level)) {
		char *s = NULL;
		vasprintf(&s, fmt, ap);
		if (!s) return;
		DEBUG(samba_level, ("ldb: %s\n", s));
		free(s);
	}
}


/*
  connecting to a ldb can be a relatively expensive operation because
  of the schema and partition loads. We keep a list of open ldb
  contexts here, and try to re-use when possible.

  This means callers of ldb_wrap_connect() must use talloc_unlink() or
  the free of a parent to destroy the context
 */
static struct ldb_wrap {
	struct ldb_wrap *next, *prev;
	struct ldb_wrap_context {
		/* the context is what we use to tell if two ldb
		 * connections are exactly equivalent
		 */
		const char *url;
		struct tevent_context *ev;
		struct loadparm_context *lp_ctx;
		struct auth_session_info *session_info;
		struct cli_credentials *credentials;
		unsigned int flags;
	} context;
	struct ldb_context *ldb;
} *ldb_wrap_list;

/*
   free a ldb_wrap structure
 */
static int ldb_wrap_destructor(struct ldb_wrap *w)
{
	DLIST_REMOVE(ldb_wrap_list, w);
	return 0;
}

/*
 * The casefolder for s4's LDB databases - Unicode-safe
 */
char *wrap_casefold(void *context, void *mem_ctx, const char *s, size_t n)
{
	return strupper_talloc_n(mem_ctx, s, n);
}


 struct ldb_context *samba_ldb_init(TALLOC_CTX *mem_ctx,
				    struct tevent_context *ev,
				    struct loadparm_context *lp_ctx,
				    struct auth_session_info *session_info,
				    struct cli_credentials *credentials)
{
	struct ldb_context *ldb;
	int ret;

	ldb = ldb_init(mem_ctx, ev);
	if (ldb == NULL) {
		return NULL;
	}

	ldb_set_modules_dir(ldb, modules_path(ldb, "ldb"));

	ldb_set_debug(ldb, ldb_wrap_debug, NULL);

	ldb_set_utf8_fns(ldb, NULL, wrap_casefold);

	if (session_info) {
		if (ldb_set_opaque(ldb, "sessionInfo", session_info)) {
			talloc_free(ldb);
			return NULL;
		}
	}

	if (credentials) {
		if (ldb_set_opaque(ldb, "credentials", credentials)) {
			talloc_free(ldb);
			return NULL;
		}
	}

	if (ldb_set_opaque(ldb, "loadparm", lp_ctx)) {
		talloc_free(ldb);
		return NULL;
	}

	/* This must be done before we load the schema, as these
	 * handlers for objectSid and objectGUID etc must take
	 * precedence over the 'binary attribute' declaration in the
	 * schema */
	ret = ldb_register_samba_handlers(ldb);
	if (ret != LDB_SUCCESS) {
		talloc_free(ldb);
		return NULL;
	}

	/* we usually want Samba databases to be private. If we later
	   find we need one public, we will need to add a parameter to
	   ldb_wrap_connect() */
	ldb_set_create_perms(ldb, 0600);

	return ldb;
}

 struct ldb_context *ldb_wrap_find(const char *url,
				   struct tevent_context *ev,
				   struct loadparm_context *lp_ctx,
				   struct auth_session_info *session_info,
				   struct cli_credentials *credentials,
				   unsigned int flags)
{
	struct ldb_wrap *w;
	/* see if we can re-use an existing ldb */
	for (w=ldb_wrap_list; w; w=w->next) {
		if (w->context.ev == ev &&
		    w->context.lp_ctx == lp_ctx &&
		    w->context.session_info == session_info &&
		    w->context.credentials == credentials &&
		    w->context.flags == flags &&
		    (w->context.url == url || strcmp(w->context.url, url) == 0))
			return w->ldb;
	}

	return NULL;
}

int samba_ldb_connect(struct ldb_context *ldb, struct loadparm_context *lp_ctx,
		      const char *url, unsigned int flags)
{
	int ret;
	char *real_url = NULL;

	/* allow admins to force non-sync ldb for all databases */
	if (lpcfg_parm_bool(lp_ctx, NULL, "ldb", "nosync", false)) {
		flags |= LDB_FLG_NOSYNC;
	}

	if (DEBUGLVL(10)) {
		flags |= LDB_FLG_ENABLE_TRACING;
	}

	real_url = lpcfg_private_path(ldb, lp_ctx, url);
	if (real_url == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ldb_connect(ldb, real_url, flags, NULL);

	if (ret != LDB_SUCCESS) {
		return ret;
	}

	/* setup for leak detection */
	ldb_set_opaque(ldb, "wrap_url", real_url);

	return LDB_SUCCESS;
}

 bool ldb_wrap_add(const char *url, struct tevent_context *ev,
		   struct loadparm_context *lp_ctx,
		   struct auth_session_info *session_info,
		   struct cli_credentials *credentials,
		   unsigned int flags,
		   struct ldb_context *ldb)
{
	struct ldb_wrap *w;
	struct ldb_wrap_context c;

	/* add to the list of open ldb contexts */
	w = talloc(ldb, struct ldb_wrap);
	if (w == NULL) {
		return false;
	}

	c.url          = url;
	c.ev           = ev;
	c.lp_ctx       = lp_ctx;
	c.session_info = session_info;
	c.credentials  = credentials;
	c.flags        = flags;

	w->context = c;
	w->context.url = talloc_strdup(w, url);
	if (w->context.url == NULL) {
		return false;
	}

	if (session_info) {
		/* take a reference to the session_info, as it is
		 * possible for the ldb to live longer than the
		 * session_info. This happens when a DRS DsBind call
		 * reuses a handle, but the original connection is
		 * shutdown. The token for the new connection is still
		 * valid, so we need the session_info to remain valid for
		 * ldb modules to use
		 */
		if (talloc_reference(w, session_info) == NULL) {
			return false;
		}
	}

	w->ldb = ldb;

	DLIST_ADD(ldb_wrap_list, w);

	talloc_set_destructor(w, ldb_wrap_destructor);

	return true;
}


/*
  wrapped connection to a ldb database
  to close just talloc_free() the returned ldb_context

  TODO:  We need an error_string parameter
 */
 struct ldb_context *ldb_wrap_connect(TALLOC_CTX *mem_ctx,
				      struct tevent_context *ev,
				      struct loadparm_context *lp_ctx,
				      const char *url,
				      struct auth_session_info *session_info,
				      struct cli_credentials *credentials,
				      unsigned int flags)
{
	struct ldb_context *ldb;
	int ret;

	ldb = ldb_wrap_find(url, ev, lp_ctx, session_info, credentials, flags);
	if (ldb != NULL)
		return talloc_reference(mem_ctx, ldb);

	ldb = samba_ldb_init(mem_ctx, ev, lp_ctx, session_info, credentials);

	if (ldb == NULL)
		return NULL;

	ret = samba_ldb_connect(ldb, lp_ctx, url, flags);
	if (ret != LDB_SUCCESS) {
		talloc_free(ldb);
		return NULL;
	}

	if (!ldb_wrap_add(url, ev, lp_ctx, session_info, credentials, flags, ldb)) {
		talloc_free(ldb);
		return NULL;
	}

	DEBUG(3,("ldb_wrap open of %s\n", url));

	return ldb;
}

/*
  when we fork() we need to make sure that any open ldb contexts have
  any open transactions cancelled (ntdb databases doesn't need reopening,
  as we don't use clear_if_first).
 */
 void ldb_wrap_fork_hook(void)
{
	struct ldb_wrap *w;

	for (w=ldb_wrap_list; w; w=w->next) {
		if (ldb_transaction_cancel_noerr(w->ldb) != LDB_SUCCESS) {
			smb_panic("Failed to cancel child transactions\n");
		}
	}

	if (tdb_reopen_all(1) != 0) {
		smb_panic("tdb_reopen_all failed\n");
	}
}

 char *ldb_relative_path(struct ldb_context *ldb,
			 TALLOC_CTX *mem_ctx,
			 const char *name)
{
	const char *base_url =
		(const char *)ldb_get_opaque(ldb, "ldb_url");
	char *path, *p, *full_name;
	if (name == NULL) {
		return NULL;
	}
	if (strncmp("tdb://", base_url, 6) == 0) {
		base_url = base_url+6;
	}
	path = talloc_strdup(mem_ctx, base_url);
	if (path == NULL) {
		return NULL;
	}
	if ( (p = strrchr(path, '/')) != NULL) {
		p[0] = '\0';
		full_name = talloc_asprintf(mem_ctx, "%s/%s", path, name);
	} else {
		full_name = talloc_asprintf(mem_ctx, "./%s", name);
	}
	talloc_free(path);
	return full_name;
}