summaryrefslogtreecommitdiff
path: root/source4/dsdb/samdb/ldb_modules/subtree_delete.c
blob: e84bf60b328074e9c27327e48849d842eb2caa58 (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
/* 
   ldb database library

   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2006-2007
   Copyright (C) Stefan Metzmacher <metze@samba.org> 2007

   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/>.
*/

/*
 *  Name: ldb
 *
 *  Component: ldb subtree delete (prevention) module
 *
 *  Description: Prevent deletion of a subtree in LDB
 *
 *  Author: Andrew Bartlett
 */

#include "ldb_includes.h"

struct subtree_delete_context {
	enum sd_step {SD_SEARCH, SD_DO_DEL} step;

	struct ldb_module *module;
	struct ldb_handle *handle;
	struct ldb_request *orig_req;

	struct ldb_request *search_req;
	struct ldb_request *down_req;

	int num_children;
};

static struct subtree_delete_context *subtree_delete_init_handle(struct ldb_request *req, 
								 struct ldb_module *module)
{
	struct subtree_delete_context *ac;
	struct ldb_handle *h;

	h = talloc_zero(req, struct ldb_handle);
	if (h == NULL) {
		ldb_set_errstring(module->ldb, "Out of Memory");
		return NULL;
	}

	h->module = module;

	ac = talloc_zero(h, struct subtree_delete_context);
	if (ac == NULL) {
		ldb_set_errstring(module->ldb, "Out of Memory");
		talloc_free(h);
		return NULL;
	}

	h->private_data	= ac;

	ac->module = module;
	ac->handle = h;
	ac->orig_req = req;

	req->handle = h;

	return ac;
}

static int subtree_delete_check_for_children(struct subtree_delete_context *ac)
{
	if (ac->num_children > 0) {
		ldb_asprintf_errstring(ac->module->ldb, "Cannot delete %s, not a leaf node (has %d children)\n",
				       ldb_dn_get_linearized(ac->orig_req->op.del.dn), ac->num_children);
		return LDB_ERR_NOT_ALLOWED_ON_NON_LEAF;
	} else {
		struct ldb_request *req = talloc(ac, struct ldb_request);
		if (!req) {
			ldb_oom(ac->module->ldb);
			return LDB_ERR_OPERATIONS_ERROR;
		}
		*req = *ac->orig_req;
		
		/* Ensure any (io) errors during the search for
		 * children don't propgate back in the error string */
		ldb_set_errstring(ac->module->ldb, NULL);

		ac->down_req = req;
		ac->step = SD_DO_DEL;
		return ldb_next_request(ac->module, req);
	}
}

static int subtree_delete_search_callback(struct ldb_context *ldb, void *context, struct ldb_reply *ares) 
{
	struct subtree_delete_context *ac = talloc_get_type(context, struct subtree_delete_context);
	TALLOC_CTX *mem_ctx = talloc_new(ac);
    
	if (!mem_ctx) {
		ldb_oom(ac->module->ldb);
		return LDB_ERR_OPERATIONS_ERROR;
	}
	/* OK, we have one of *many* search results here:

	   We should also get the entry we tried to rename.  This
	   callback handles this and everything below it.
	 */

	/* Only entries are interesting, and we handle the case of the parent seperatly */
	if (ares->type == LDB_REPLY_ENTRY
	    && ldb_dn_compare(ares->message->dn, ac->orig_req->op.del.dn) != 0) {
		/* And it is an actual entry: now object bitterly that we are not a leaf node */
		ac->num_children++;
	}
	talloc_free(ares);
	return LDB_SUCCESS;
}

/* rename */
static int subtree_delete(struct ldb_module *module, struct ldb_request *req)
{
	const char *attrs[] = { NULL };
	struct ldb_request *new_req;
	struct subtree_delete_context *ac;
	int ret;
	if (ldb_dn_is_special(req->op.rename.olddn)) { /* do not manipulate our control entries */
		return ldb_next_request(module, req);
	}

	/* This gets complex:  We need to:
	   - Do a search for all entires under this entry 
	   - Wait for these results to appear
	   - In the callback for each result, count the children (if any)
	   - return an error if there are any
	*/

	ac = subtree_delete_init_handle(req, module);
	if (!ac) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ldb_build_search_req(&new_req, module->ldb, req,
				   req->op.del.dn, 
				   LDB_SCOPE_SUBTREE,
				   "(objectClass=*)",
				   attrs,
				   req->controls,
				   ac, 
				   subtree_delete_search_callback);

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

	ac->search_req = new_req;
	if (req == NULL) {
		ldb_oom(ac->module->ldb);
		return LDB_ERR_OPERATIONS_ERROR;
	}
	return ldb_next_request(module, new_req);
}


static int subtree_delete_wait_none(struct ldb_handle *handle) {
	struct subtree_delete_context *ac;
	int ret = LDB_ERR_OPERATIONS_ERROR;
	if (!handle || !handle->private_data) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	if (handle->state == LDB_ASYNC_DONE) {
		return handle->status;
	}

	handle->state = LDB_ASYNC_PENDING;
	handle->status = LDB_SUCCESS;

	ac = talloc_get_type(handle->private_data, struct subtree_delete_context);

	switch (ac->step) {
	case SD_SEARCH:
		ret = ldb_wait(ac->search_req->handle, LDB_WAIT_NONE);

		if (ret != LDB_SUCCESS && ret != LDB_ERR_NO_SUCH_OBJECT) {
			handle->status = ret;
			goto done;
		}
		if (ac->search_req->handle->status != LDB_SUCCESS
			&& ac->search_req->handle->status != LDB_ERR_NO_SUCH_OBJECT) {
			handle->status = ac->search_req->handle->status;
			goto done;
		}

		return subtree_delete_check_for_children(ac);

	case SD_DO_DEL:
		ret = ldb_wait(ac->down_req->handle, LDB_WAIT_NONE);

		if (ret != LDB_SUCCESS) {
			handle->status = ret;
			goto done;
		}
		if (ac->down_req->handle->status != LDB_SUCCESS) {
			handle->status = ac->down_req->handle->status;
			goto done;
		}

		if (ac->down_req->handle->state != LDB_ASYNC_DONE) {
			return LDB_SUCCESS;
		}

		break;
	}
done:
	handle->state = LDB_ASYNC_DONE;
	return ret;
}

static int subtree_delete_wait_all(struct ldb_handle *handle) {

	int ret;

	while (handle->state != LDB_ASYNC_DONE) {
		ret = subtree_delete_wait_none(handle);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}

	return handle->status;
}

static int subtree_delete_wait(struct ldb_handle *handle, enum ldb_wait_type type)
{
	if (type == LDB_WAIT_ALL) {
		return subtree_delete_wait_all(handle);
	} else {
		return subtree_delete_wait_none(handle);
	}
}

static const struct ldb_module_ops subtree_delete_ops = {
	.name		   = "subtree_delete",
	.del               = subtree_delete,
	.wait              = subtree_delete_wait,
};

int ldb_subtree_delete_init(void)
{
	return ldb_register_module(&subtree_delete_ops);
}