source: branches/samba-3.2.x/source/lib/ldb/common/ldb_modules.c@ 1075

Last change on this file since 1075 was 138, checked in by Paul Smedley, 17 years ago

Update source to 3.2.0 GA level
File size: 11.3 KB
Line 
1
2/*
3 ldb database library
4
5 Copyright (C) Simo Sorce 2004
6
7 ** NOTE! The following LGPL license applies to the ldb
8 ** library. This does NOT imply that all of Samba is released
9 ** under the LGPL
10
11 This library is free software; you can redistribute it and/or
12 modify it under the terms of the GNU Lesser General Public
13 License as published by the Free Software Foundation; either
14 version 3 of the License, or (at your option) any later version.
15
16 This library is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 Lesser General Public License for more details.
20
21 You should have received a copy of the GNU Lesser General Public
22 License along with this library; if not, see <http://www.gnu.org/licenses/>.
23*/
24
25/*
26 * Name: ldb
27 *
28 * Component: ldb modules core
29 *
30 * Description: core modules routines
31 *
32 * Author: Simo Sorce
33 */
34
35#include "includes.h"
36#include "ldb/include/includes.h"
37
38#if (_SAMBA_BUILD_ >= 4)
39#include "build.h"
40#include "dynconfig.h"
41#endif
42
43#define LDB_MODULE_PREFIX "modules:"
44#define LDB_MODULE_PREFIX_LEN 8
45
46static char *ldb_modules_strdup_no_spaces(TALLOC_CTX *mem_ctx, const char *string)
47{
48 int i, len;
49 char *trimmed;
50
51 trimmed = talloc_strdup(mem_ctx, string);
52 if (!trimmed) {
53 return NULL;
54 }
55
56 len = strlen(trimmed);
57 for (i = 0; trimmed[i] != '\0'; i++) {
58 switch (trimmed[i]) {
59 case ' ':
60 case '\t':
61 case '\n':
62 memmove(&trimmed[i], &trimmed[i + 1], len -i -1);
63 break;
64 }
65 }
66
67 return trimmed;
68}
69
70
71/* modules are called in inverse order on the stack.
72 Lets place them as an admin would think the right order is.
73 Modules order is important */
74const char **ldb_modules_list_from_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *string)
75{
76 char **modules = NULL;
77 const char **m;
78 char *modstr, *p;
79 int i;
80
81 /* spaces not admitted */
82 modstr = ldb_modules_strdup_no_spaces(mem_ctx, string);
83 if ( ! modstr) {
84 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_strdup_no_spaces()\n");
85 return NULL;
86 }
87
88 modules = talloc_realloc(mem_ctx, modules, char *, 2);
89 if ( ! modules ) {
90 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
91 talloc_free(modstr);
92 return NULL;
93 }
94 talloc_steal(modules, modstr);
95
96 i = 0;
97 /* The str*r*chr walks backwards: This is how we get the inverse order mentioned above */
98 while ((p = strrchr(modstr, ',')) != NULL) {
99 *p = '\0';
100 p++;
101 modules[i] = p;
102
103 i++;
104 modules = talloc_realloc(mem_ctx, modules, char *, i + 2);
105 if ( ! modules ) {
106 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
107 return NULL;
108 }
109
110 }
111 modules[i] = modstr;
112
113 modules[i + 1] = NULL;
114
115 m = (const char **)modules;
116
117 return m;
118}
119
120static struct ops_list_entry {
121 const struct ldb_module_ops *ops;
122 struct ops_list_entry *next;
123} *registered_modules = NULL;
124
125static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
126{
127 struct ops_list_entry *e;
128
129 for (e = registered_modules; e; e = e->next) {
130 if (strcmp(e->ops->name, name) == 0)
131 return e->ops;
132 }
133
134 return NULL;
135}
136
137#ifndef STATIC_ldb_MODULES
138
139#ifdef HAVE_LDB_LDAP
140#define LDAP_INIT ldb_ldap_init,
141#else
142#define LDAP_INIT
143#endif
144
145#ifdef HAVE_LDB_SQLITE3
146#define SQLITE3_INIT ldb_sqlite3_init,
147#else
148#define SQLITE3_INIT
149#endif
150
151#define STATIC_ldb_MODULES \
152 { \
153 LDAP_INIT \
154 SQLITE3_INIT \
155 ldb_tdb_init, \
156 ldb_operational_init, \
157 ldb_rdn_name_init, \
158 ldb_objectclass_init, \
159 ldb_paged_results_init, \
160 ldb_sort_init, \
161 ldb_asq_init, \
162 NULL \
163 }
164#endif
165
166int ldb_global_init(void)
167{
168 static int (*static_init_fns[])(void) = STATIC_ldb_MODULES;
169
170 static int initialized = 0;
171 int ret = 0, i;
172
173 if (initialized)
174 return 0;
175
176 initialized = 1;
177
178 for (i = 0; static_init_fns[i]; i++) {
179 if (static_init_fns[i]() == -1)
180 ret = -1;
181 }
182
183 return ret;
184}
185
186int ldb_register_module(const struct ldb_module_ops *ops)
187{
188 struct ops_list_entry *entry = talloc(talloc_autofree_context(), struct ops_list_entry);
189
190 if (ldb_find_module_ops(ops->name) != NULL)
191 return -1;
192
193 if (entry == NULL)
194 return -1;
195
196 entry->ops = ops;
197 entry->next = registered_modules;
198 registered_modules = entry;
199
200 return 0;
201}
202
203int ldb_try_load_dso(struct ldb_context *ldb, const char *name)
204{
205 char *path;
206 void *handle;
207 int (*init_fn) (void);
208 char *modulesdir;
209 int ret;
210
211#ifdef HAVE_DLOPEN
212 if (getenv("LD_LDB_MODULE_PATH") != NULL) {
213 modulesdir = talloc_strdup(ldb, getenv("LD_LDB_MODULE_PATH"));
214 } else {
215#ifdef _SAMBA_BUILD_
216 modulesdir = talloc_asprintf(ldb, "%s/ldb", get_dyn_LIBDIR());
217#else
218 modulesdir = talloc_strdup(ldb, MODULESDIR);
219#endif
220 }
221
222 path = talloc_asprintf(ldb, "%s/%s.%s", modulesdir, name, SHLIBEXT);
223
224 talloc_free(modulesdir);
225
226 ldb_debug(ldb, LDB_DEBUG_TRACE, "trying to load %s from %s\n", name, path);
227
228 handle = dlopen(path, RTLD_NOW);
229 if (handle == NULL) {
230 ldb_debug(ldb, LDB_DEBUG_WARNING, "unable to load %s from %s: %s\n", name, path, dlerror());
231 return -1;
232 }
233
234 init_fn = (int (*)(void))dlsym(handle, "init_samba_module");
235
236 if (init_fn == NULL) {
237 ldb_debug(ldb, LDB_DEBUG_ERROR, "no symbol "
238 "`init_samba_module' found in %s: %s\n", path,
239 dlerror());
240 dlclose(handle);
241 return -1;
242 }
243
244 talloc_free(path);
245
246 ret = init_fn();
247 if (ret == -1) {
248 dlclose(handle);
249 }
250 return ret;
251#else
252 ldb_debug(ldb, LDB_DEBUG_TRACE, "no dlopen() - not trying to load %s module\n", name);
253 return -1;
254#endif
255}
256
257int ldb_load_modules_list(struct ldb_context *ldb, const char **module_list, struct ldb_module *backend, struct ldb_module **out)
258{
259 struct ldb_module *module;
260 int i;
261
262 module = backend;
263
264 for (i = 0; module_list[i] != NULL; i++) {
265 struct ldb_module *current;
266 const struct ldb_module_ops *ops;
267
268 ops = ldb_find_module_ops(module_list[i]);
269 if (ops == NULL) {
270 if (ldb_try_load_dso(ldb, module_list[i]) == 0) {
271 ops = ldb_find_module_ops(module_list[i]);
272 }
273 }
274
275 if (ops == NULL) {
276 ldb_debug(ldb, LDB_DEBUG_WARNING, "WARNING: Module [%s] not found\n",
277 module_list[i]);
278 continue;
279 }
280
281 current = talloc_zero(ldb, struct ldb_module);
282 if (current == NULL) {
283 return LDB_ERR_OPERATIONS_ERROR;
284 }
285 talloc_set_name(current, "ldb_module: %s", module_list[i]);
286
287 current->ldb = ldb;
288 current->ops = ops;
289
290 DLIST_ADD(module, current);
291 }
292 *out = module;
293 return LDB_SUCCESS;
294}
295
296int ldb_init_module_chain(struct ldb_context *ldb, struct ldb_module *module)
297{
298 while (module && module->ops->init_context == NULL)
299 module = module->next;
300
301 if (module && module->ops->init_context &&
302 module->ops->init_context(module) != LDB_SUCCESS) {
303 ldb_debug(ldb, LDB_DEBUG_FATAL, "module initialization failed\n");
304 return LDB_ERR_OPERATIONS_ERROR;
305 }
306
307 return LDB_SUCCESS;
308}
309
310int ldb_load_modules(struct ldb_context *ldb, const char *options[])
311{
312 const char **modules = NULL;
313 int i;
314 int ret;
315 TALLOC_CTX *mem_ctx = talloc_new(ldb);
316 if (!mem_ctx) {
317 return LDB_ERR_OPERATIONS_ERROR;
318 }
319
320 /* find out which modules we are requested to activate */
321
322 /* check if we have a custom module list passd as ldb option */
323 if (options) {
324 for (i = 0; options[i] != NULL; i++) {
325 if (strncmp(options[i], LDB_MODULE_PREFIX, LDB_MODULE_PREFIX_LEN) == 0) {
326 modules = ldb_modules_list_from_string(ldb, mem_ctx, &options[i][LDB_MODULE_PREFIX_LEN]);
327 }
328 }
329 }
330
331 /* if not overloaded by options and the backend is not ldap try to load the modules list from ldb */
332 if ((modules == NULL) && (strcmp("ldap", ldb->modules->ops->name) != 0)) {
333 const char * const attrs[] = { "@LIST" , NULL};
334 struct ldb_result *res = NULL;
335 struct ldb_dn *mods_dn;
336
337 mods_dn = ldb_dn_explode(mem_ctx, "@MODULES");
338 if (mods_dn == NULL) {
339 talloc_free(mem_ctx);
340 return -1;
341 }
342
343 ret = ldb_search(ldb, mods_dn, LDB_SCOPE_BASE, "", attrs, &res);
344 talloc_steal(mods_dn, res);
345 if (ret == LDB_SUCCESS && (res->count == 0 || res->msgs[0]->num_elements == 0)) {
346 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db\n");
347 } else {
348 if (ret != LDB_SUCCESS) {
349 ldb_debug(ldb, LDB_DEBUG_FATAL, "ldb error (%s) occurred searching for modules, bailing out\n", ldb_errstring(ldb));
350 talloc_free(mem_ctx);
351 return -1;
352 }
353 if (res->count > 1) {
354 ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found (%d), bailing out\n", res->count);
355 talloc_free(mem_ctx);
356 return -1;
357 }
358
359 modules = ldb_modules_list_from_string(ldb, mem_ctx,
360 (const char *)res->msgs[0]->elements[0].values[0].data);
361
362 }
363
364 talloc_free(mods_dn);
365 }
366
367 if (modules != NULL) {
368 ret = ldb_load_modules_list(ldb, modules, ldb->modules, &ldb->modules);
369 talloc_free(modules);
370 if (ret != LDB_SUCCESS) {
371 return ret;
372 }
373 } else {
374 ldb_debug(ldb, LDB_DEBUG_TRACE, "No modules specified for this database\n");
375 }
376
377 return ldb_init_module_chain(ldb, ldb->modules);
378}
379
380/*
381 by using this we allow ldb modules to only implement the functions they care about,
382 which makes writing a module simpler, and makes it more likely to keep working
383 when ldb is extended
384*/
385#define FIND_OP(module, op) do { \
386 struct ldb_context *ldb = module->ldb; \
387 module = module->next; \
388 while (module && module->ops->op == NULL) module = module->next; \
389 if (module == NULL) { \
390 ldb_asprintf_errstring(ldb, "Unable to find backend operation for " #op ); \
391 return LDB_ERR_OPERATIONS_ERROR; \
392 } \
393} while (0)
394
395
396/*
397 helper functions to call the next module in chain
398*/
399
400int ldb_next_request(struct ldb_module *module, struct ldb_request *request)
401{
402 switch (request->operation) {
403 case LDB_SEARCH:
404 FIND_OP(module, search);
405 return module->ops->search(module, request);
406 case LDB_ADD:
407 FIND_OP(module, add);
408 return module->ops->add(module, request);
409 case LDB_MODIFY:
410 FIND_OP(module, modify);
411 return module->ops->modify(module, request);
412 case LDB_DELETE:
413 FIND_OP(module, del);
414 return module->ops->del(module, request);
415 case LDB_RENAME:
416 FIND_OP(module, rename);
417 return module->ops->rename(module, request);
418 case LDB_SEQUENCE_NUMBER:
419 FIND_OP(module, sequence_number);
420 return module->ops->sequence_number(module, request);
421 default:
422 FIND_OP(module, request);
423 return module->ops->request(module, request);
424 }
425}
426
427int ldb_next_init(struct ldb_module *module)
428{
429 /* init is different in that it is not an error if modules
430 * do not require initialization */
431
432 module = module->next;
433
434 while (module && module->ops->init_context == NULL)
435 module = module->next;
436
437 if (module == NULL)
438 return LDB_SUCCESS;
439
440 return module->ops->init_context(module);
441}
442
443int ldb_next_start_trans(struct ldb_module *module)
444{
445 FIND_OP(module, start_transaction);
446 return module->ops->start_transaction(module);
447}
448
449int ldb_next_end_trans(struct ldb_module *module)
450{
451 FIND_OP(module, end_transaction);
452 return module->ops->end_transaction(module);
453}
454
455int ldb_next_del_trans(struct ldb_module *module)
456{
457 FIND_OP(module, del_transaction);
458 return module->ops->del_transaction(module);
459}
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