summaryrefslogtreecommitdiff
path: root/source4/lib/ldb/modules/paged_searches.c
blob: 39780cb6994104cac5a839bd3301a1ea601eb4ce (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
/* 
   ldb database library

   Copyright (C) Simo Sorce  2005-2008
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2009

     ** NOTE! The following LGPL license applies to the ldb
     ** library. This does NOT imply that all of Samba is released
     ** under the LGPL
   
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 3 of the License, or (at your option) any later version.

   This library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/

/*
 *  Name: paged_searches
 *
 *  Component: ldb paged searches module
 *
 *  Description: this module detects if the remote ldap server supports
 *               paged results and use them to transparently access all objects
 *
 *  Author: Simo Sorce
 */

#include "includes.h"
#include "ldb_module.h"

#define PS_DEFAULT_PAGE_SIZE 500
/* 500 objects per query seem to be a decent compromise
 * the default AD limit per request is 1000 entries */

struct private_data {

	bool paged_supported;
};

struct ps_context {
	struct ldb_module *module;
	struct ldb_request *req;

	bool pending;

	char **saved_referrals;
	unsigned int num_referrals;

	struct ldb_request *down_req;
};

static int check_ps_continuation(struct ps_context *ac, struct ldb_request *req, struct ldb_reply *ares)
{
	struct ldb_context *ldb;
	struct ldb_control *rep_control, *req_control;
	struct ldb_paged_control *paged_rep_control = NULL, *paged_req_control = NULL;
	ldb = ldb_module_get_ctx(ac->module);

	rep_control = ldb_reply_get_control(ares, LDB_CONTROL_PAGED_RESULTS_OID);
	if (rep_control) {
		paged_rep_control = talloc_get_type(rep_control->data, struct ldb_paged_control);
	}

	req_control = ldb_request_get_control(req, LDB_CONTROL_PAGED_RESULTS_OID);
	paged_req_control = talloc_get_type(req_control->data, struct ldb_paged_control);

	if (!rep_control || !paged_rep_control) {
		if (paged_req_control->cookie) {
			/* something wrong here - why give us a control back befre, but not one now? */
			ldb_set_errstring(ldb, "paged_searches:  ERROR: We got back a control from a previous page, but this time no control was returned!");
			return LDB_ERR_OPERATIONS_ERROR;
		} else {
			/* No cookie received yet, valid to just return the full data set */

			/* we are done */
			ac->pending = false;
			return LDB_SUCCESS;
		}
	}

	if (paged_rep_control->cookie_len == 0) {
		/* we are done */
		ac->pending = false;
		return LDB_SUCCESS;
	}

	/* more processing required */
	/* let's fill in the request control with the new cookie */
	/* if there's a reply control we must find a request
	 * control matching it */

	if (paged_req_control->cookie) {
		talloc_free(paged_req_control->cookie);
	}

	paged_req_control->cookie = talloc_memdup(req_control,
						  paged_rep_control->cookie,
						  paged_rep_control->cookie_len);
	paged_req_control->cookie_len = paged_rep_control->cookie_len;

	ac->pending = true;
	return LDB_SUCCESS;
}

static int store_referral(struct ps_context *ac, char *referral)
{
	ac->saved_referrals = talloc_realloc(ac, ac->saved_referrals, char *, ac->num_referrals + 2);
	if (!ac->saved_referrals) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ac->saved_referrals[ac->num_referrals] = talloc_strdup(ac->saved_referrals, referral);
	if (!ac->saved_referrals[ac->num_referrals]) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ac->num_referrals++;
	ac->saved_referrals[ac->num_referrals] = NULL;

	return LDB_SUCCESS;
}

static int send_referrals(struct ps_context *ac)
{
	struct ldb_reply *ares;
	int ret;
	unsigned int i;

	for (i = 0; i < ac->num_referrals; i++) {
		ares = talloc_zero(ac->req, struct ldb_reply);
		if (!ares) {
			return LDB_ERR_OPERATIONS_ERROR;
		}

		ares->type = LDB_REPLY_REFERRAL;
		ares->referral = ac->saved_referrals[i];

		ret = ldb_module_send_referral(ac->req, ares->referral);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}

	return LDB_SUCCESS;
}

static int ps_callback(struct ldb_request *req, struct ldb_reply *ares)
{
	struct ps_context *ac;
	int ret;

	ac = talloc_get_type(req->context, struct ps_context);

	if (!ares) {
		return ldb_module_done(ac->req, NULL, NULL,
					LDB_ERR_OPERATIONS_ERROR);
	}
	if (ares->error != LDB_SUCCESS) {
		return ldb_module_done(ac->req, ares->controls,
					ares->response, ares->error);
	}

	switch (ares->type) {
	case LDB_REPLY_ENTRY:
		ret = ldb_module_send_entry(ac->req, ares->message, ares->controls);
		if (ret != LDB_SUCCESS) {
			return ldb_module_done(ac->req, NULL, NULL, ret);
		}
		break;

	case LDB_REPLY_REFERRAL:
		ret = store_referral(ac, ares->referral);
		if (ret != LDB_SUCCESS) {
			return ldb_module_done(ac->req, NULL, NULL, ret);
		}
		break;

	case LDB_REPLY_DONE:

		ret = check_ps_continuation(ac, req, ares);
		if (ret != LDB_SUCCESS) {
			return ldb_module_done(ac->req, NULL, NULL, ret);
		}

		if (ac->pending) {

			ret = ldb_next_request(ac->module, ac->down_req);

			if (ret != LDB_SUCCESS) {
				return ldb_module_done(ac->req,
							NULL, NULL, ret);
			}

		} else {

			/* send referrals */
			ret = send_referrals(ac);
			if (ret != LDB_SUCCESS) {
				return ldb_module_done(ac->req,
							NULL, NULL, ret);
			}

			/* send REPLY_DONE */
			return ldb_module_done(ac->req, ares->controls,
						ares->response, LDB_SUCCESS);
		}
		break;
	}

	talloc_free(ares);
	return LDB_SUCCESS;
}

static int ps_search(struct ldb_module *module, struct ldb_request *req)
{
	struct ldb_context *ldb;
	struct private_data *private_data;
	struct ps_context *ac;
	struct ldb_paged_control *control;
	int ret;

	private_data = talloc_get_type(ldb_module_get_private(module), struct private_data);
	ldb = ldb_module_get_ctx(module);

	/* check if paging is supported */
	if (!private_data || !private_data->paged_supported) {
		/* do not touch this request paged controls not
		 * supported or we
		 * are just not setup yet */
		return ldb_next_request(module, req);
	}

	ac = talloc_zero(req, struct ps_context);
	if (ac == NULL) {
		ldb_oom(ldb);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ac->module = module;
	ac->req = req;
	ac->pending = false;
	ac->saved_referrals = NULL;
	ac->num_referrals = 0;

	ldb = ldb_module_get_ctx(ac->module);

	control = talloc(ac, struct ldb_paged_control);
	if (!control) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	control->size = PS_DEFAULT_PAGE_SIZE;
	control->cookie = NULL;
	control->cookie_len = 0;

	ret = ldb_build_search_req_ex(&ac->down_req, ldb, ac,
					ac->req->op.search.base,
					ac->req->op.search.scope,
					ac->req->op.search.tree,
					ac->req->op.search.attrs,
					ac->req->controls,
					ac,
					ps_callback,
					ac->req);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	ret = ldb_request_add_control(ac->down_req, LDB_CONTROL_PAGED_RESULTS_OID,
				      true, control);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	talloc_steal(ac->down_req, control);

	return ldb_next_request(ac->module, ac->down_req);
}

static int check_supported_paged(struct ldb_request *req,
				 struct ldb_reply *ares)
{
	struct private_data *data;

	data = talloc_get_type(req->context, struct private_data);

	if (!ares) {
		return ldb_request_done(req, LDB_ERR_OPERATIONS_ERROR);
	}
	if (ares->error != LDB_SUCCESS) {
		return ldb_request_done(req, LDB_ERR_OPERATIONS_ERROR);
	}

	switch (ares->type) {
	case LDB_REPLY_ENTRY:
		if (ldb_msg_check_string_attribute(ares->message,
						   "supportedControl",
						   LDB_CONTROL_PAGED_RESULTS_OID)) {
			data->paged_supported = true;
		}
		break;

	case LDB_REPLY_REFERRAL:
		/* ignore */
		break;

	case LDB_REPLY_DONE:
		return ldb_request_done(req, LDB_SUCCESS);
	}

	talloc_free(ares);
	return LDB_SUCCESS;
}

static int ps_init(struct ldb_module *module)
{
	struct ldb_context *ldb;
	static const char *attrs[] = { "supportedControl", NULL };
	struct private_data *data;
	struct ldb_dn *base;
	int ret;
	struct ldb_request *req;

	ldb = ldb_module_get_ctx(module);

	data = talloc(module, struct private_data);
	if (data == NULL) {
		ldb_oom(ldb);
		return LDB_ERR_OPERATIONS_ERROR;
	}
	data->paged_supported = false;

	ldb_module_set_private(module, data);

	base = ldb_dn_new(module, ldb, "");
	if (base == NULL) {
		ldb_oom(ldb);
		return LDB_ERR_OPERATIONS_ERROR;
	}
	ret = ldb_build_search_req(&req, ldb, module,
				   base, LDB_SCOPE_BASE,
				   "(objectClass=*)",
				   attrs, NULL,
				   data, check_supported_paged,
				   NULL);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	ret = ldb_next_request(module, req);
	if (ret == LDB_SUCCESS) {
		ret = ldb_wait(req->handle, LDB_WAIT_ALL);
	}
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	talloc_free(base);
	talloc_free(req);

	return ldb_next_init(module);
}

_PUBLIC_ const struct ldb_module_ops ldb_paged_searches_module_ops = {
	.name           = "paged_searches",
	.search         = ps_search,
	.init_context 	= ps_init
};