summaryrefslogtreecommitdiff
path: root/source4/dsdb/samdb/ldb_modules/ranged_results.c
blob: 8f368b6f14966f1aa9ea735ee2043f72149ce32d (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
/* 
   ldb database library

   Copyright (C) Andrew Bartlett 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 ranged results module
 *
 *  Description: munge AD-style 'ranged results' requests into
 *  requests for all values in an attribute, then return the range to
 *  the client.
 *
 *  Author: Andrew Bartlett
 */

#include "ldb_includes.h"

struct rr_context {
	struct ldb_request *orig_req;
	struct ldb_request *down_req;
};

static int rr_search_callback(struct ldb_context *ldb, void *context, struct ldb_reply *ares) 
{
	struct rr_context *rr_context = talloc_get_type(context, struct rr_context);
	struct ldb_request *orig_req = rr_context->orig_req;
	int i, j, ret;
	
	if (ares->type != LDB_REPLY_ENTRY) {
		return rr_context->orig_req->callback(ldb, rr_context->orig_req->context, ares);
	}

	/* Find those that are range requests from the attribute list */
	for (i = 0; orig_req->op.search.attrs[i]; i++) {
		char *p, *new_attr;
		const char *end_str;
		unsigned int start, end, orig_num_values;
		struct ldb_message_element *el;
		struct ldb_val *orig_values;
		p = strchr(orig_req->op.search.attrs[i], ';');
		if (!p) {
			continue;
		}
		if (strncasecmp(p, ";range=", strlen(";range=")) != 0) {
			continue;
		}
		if (sscanf(p, ";range=%u-*", &start) == 1) {
			end = (unsigned int)-1;
		} else if (sscanf(p, ";range=%u-%u", &start, &end) != 2) {
			continue;
		}
		new_attr = talloc_strndup(orig_req, 
					  orig_req->op.search.attrs[i],
					  (unsigned int)(p-orig_req->op.search.attrs[i]));

		if (!new_attr) {
			ldb_oom(ldb);
			return LDB_ERR_OPERATIONS_ERROR;
		}
		el = ldb_msg_find_element(ares->message, new_attr);
		talloc_free(new_attr);
		if (!el) {
			continue;
		}
		if (start > end) {
			ldb_asprintf_errstring(ldb, "range request error: start must not be greater than end");
			return LDB_ERR_UNWILLING_TO_PERFORM;
		}
		if (end >= el->num_values) {
			/* Need to leave the requested attribute in
			 * there (so add an empty one to match) */
			end_str = "*";
			end = el->num_values;
			ret = ldb_msg_add_empty(ares->message, orig_req->op.search.attrs[i], 
					       0, NULL);
			if (ret != LDB_SUCCESS) {
				return ret;
			}
		} else {
			end_str = talloc_asprintf(el, "%u", end);
		}
		orig_values = el->values;
		orig_num_values = el->num_values;

		if ((start + end < start) || (start + end < end)) {
			ldb_asprintf_errstring(ldb, "range request error: start or end would overflow!");
			return LDB_ERR_UNWILLING_TO_PERFORM;
		}

		el->values = talloc_array(el, struct ldb_val, end - start);
		el->num_values = 0;

		if (!el->values) {
			ldb_oom(ldb);
			return LDB_ERR_OPERATIONS_ERROR;
		}
		for (j=start; j < end; j++) {
			el->values[el->num_values] = orig_values[j];
			el->num_values++;
		}
		el->name = talloc_asprintf(el, "%s;Range=%u-%s", el->name, start, end_str);
		if (!el->name) {
			ldb_oom(ldb);
			return LDB_ERR_OPERATIONS_ERROR;
		}
	}

	return rr_context->orig_req->callback(ldb, rr_context->orig_req->context, ares);

}

/* search */
static int rr_search(struct ldb_module *module, struct ldb_request *req)
{
	int i;
	unsigned int start, end;
	const char **new_attrs = NULL;
	struct rr_context *context;
	bool found_rr = false;

	/* Strip the range request from the attribute */
	for (i = 0; req->op.search.attrs && req->op.search.attrs[i]; i++) {
		char *p;
		new_attrs = talloc_realloc(req, new_attrs, const char *, i+2);
		new_attrs[i] = req->op.search.attrs[i];
		new_attrs[i+1] = NULL;
		p = strchr(req->op.search.attrs[i], ';');
		if (!p) {
			continue;
		}
		if (strncasecmp(p, ";range=", strlen(";range=")) != 0) {
			continue;
		}
		if (sscanf(p, ";range=%u-*", &start) == 1) {
		} else if (sscanf(p, ";range=%u-%u", &start, &end) != 2) {
			ldb_asprintf_errstring(module->ldb, "range request error: range requst malformed");
			return LDB_ERR_UNWILLING_TO_PERFORM;
		}
		if (start > end) {
			ldb_asprintf_errstring(module->ldb, "range request error: start must not be greater than end");
			return LDB_ERR_UNWILLING_TO_PERFORM;
		}

		found_rr = true;
		new_attrs[i] = talloc_strndup(new_attrs, 
					      req->op.search.attrs[i],
					      (unsigned int)(p-req->op.search.attrs[i]));

		if (!new_attrs[i]) {
			ldb_oom(module->ldb);
			return LDB_ERR_OPERATIONS_ERROR;
		}
	}

	if (found_rr) {
		int ret;
		context = talloc(req, struct rr_context);
		context->orig_req = req;
		context->down_req = talloc(context, struct ldb_request);
		*context->down_req = *req;
		
		context->down_req->op.search.attrs = new_attrs;
		
		context->down_req->callback = rr_search_callback;
		context->down_req->context = context;

		ret = ldb_next_request(module, context->down_req);
		
		/* We don't need to implement our own 'wait' function, so pass the handle along */
		if (ret == LDB_SUCCESS) {
			req->handle = context->down_req->handle;
		}
		return ret;
	}

	/* No change, just run the original request as if we were never here */
	return ldb_next_request(module, req);
}

static const struct ldb_module_ops rr_ops = {
	.name		   = "ranged_results",
	.search            = rr_search,
};

int ldb_ranged_results_init(void)
{
	return ldb_register_module(&rr_ops);
}