5 Copyright (C) Simo Sorce 2004
7 ** NOTE! The following LGPL license applies to the ldb
8 ** library. This does NOT imply that all of Samba is released
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 2 of the License, or (at your option) any later version.
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.
21 You should have received a copy of the GNU Lesser General Public
22 License along with this library; if not, write to the Free Software
23 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29 * Component: ldb modules core
31 * Description: core modules routines
37 #include "ldb/include/includes.h"
41 #include "dynconfig.h"
44 #define LDB_MODULE_PREFIX "modules:"
45 #define LDB_MODULE_PREFIX_LEN 8
47 static char *talloc_strdup_no_spaces(struct ldb_context *ldb, const char *string)
52 trimmed = talloc_strdup(ldb, string);
54 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in talloc_strdup_trim_spaces()\n");
58 len = strlen(trimmed);
59 for (i = 0; trimmed[i] != '\0'; i++) {
64 memmove(&trimmed[i], &trimmed[i + 1], len -i -1);
73 /* modules are called in inverse order on the stack.
74 Lets place them as an admin would think the right order is.
75 Modules order is important */
76 const char **ldb_modules_list_from_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *string)
78 char **modules = NULL;
83 /* spaces not admitted */
84 modstr = talloc_strdup_no_spaces(mem_ctx, string);
89 modules = talloc_realloc(mem_ctx, modules, char *, 2);
91 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
95 talloc_steal(modules, modstr);
98 /* The str*r*chr walks backwards: This is how we get the inverse order mentioned above */
99 while ((p = strrchr(modstr, ',')) != NULL) {
105 modules = talloc_realloc(mem_ctx, modules, char *, i + 2);
107 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
114 modules[i + 1] = NULL;
116 m = (const char **)modules;
121 static struct ops_list_entry {
122 const struct ldb_module_ops *ops;
123 struct ops_list_entry *next;
124 } *registered_modules = NULL;
126 static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
128 struct ops_list_entry *e;
130 for (e = registered_modules; e; e = e->next) {
131 if (strcmp(e->ops->name, name) == 0)
139 #define LDAP_INIT ldb_ldap_init,
145 #define SQLITE3_INIT ldb_sqlite3_init,
150 #ifndef STATIC_ldb_MODULES
151 #define STATIC_ldb_MODULES \
157 ldb_operational_init, \
159 ldb_objectclass_init, \
160 ldb_paged_results_init, \
166 int ldb_global_init(void)
168 static int (*static_init_fns[])(void) = STATIC_ldb_MODULES;
170 static int initialized = 0;
178 for (i = 0; static_init_fns[i]; i++) {
179 if (static_init_fns[i]() == -1)
186 int ldb_register_module(const struct ldb_module_ops *ops)
188 struct ops_list_entry *entry = talloc(talloc_autofree_context(), struct ops_list_entry);
190 if (ldb_find_module_ops(ops->name) != NULL)
197 entry->next = registered_modules;
198 registered_modules = entry;
203 int ldb_try_load_dso(struct ldb_context *ldb, const char *name)
207 int (*init_fn) (void);
211 path = talloc_asprintf(ldb, "%s/ldb/%s.%s", dyn_MODULESDIR, name, dyn_SHLIBEXT);
213 path = talloc_asprintf(ldb, "%s/%s.%s", MODULESDIR, name, SHLIBEXT);
216 ldb_debug(ldb, LDB_DEBUG_TRACE, "trying to load %s from %s\n", name, path);
218 handle = dlopen(path, 0);
219 if (handle == NULL) {
220 ldb_debug(ldb, LDB_DEBUG_WARNING, "unable to load %s from %s: %s\n", name, path, dlerror());
224 init_fn = (int (*)(void))dlsym(handle, "init_module");
226 if (init_fn == NULL) {
227 ldb_debug(ldb, LDB_DEBUG_ERROR, "no symbol `init_module' found in %s: %s\n", path, dlerror());
235 ldb_debug(ldb, LDB_DEBUG_TRACE, "no dlopen() - not trying to load %s module\n", name);
240 int ldb_load_modules_list(struct ldb_context *ldb, const char **module_list, struct ldb_module *backend, struct ldb_module **out)
242 struct ldb_module *module;
247 for (i = 0; module_list[i] != NULL; i++) {
248 struct ldb_module *current;
249 const struct ldb_module_ops *ops;
251 ops = ldb_find_module_ops(module_list[i]);
253 if (ldb_try_load_dso(ldb, module_list[i]) == 0) {
254 ops = ldb_find_module_ops(module_list[i]);
259 ldb_debug(ldb, LDB_DEBUG_WARNING, "WARNING: Module [%s] not found\n",
264 current = talloc_zero(ldb, struct ldb_module);
265 if (current == NULL) {
266 return LDB_ERR_OPERATIONS_ERROR;
272 DLIST_ADD(module, current);
278 int ldb_init_module_chain(struct ldb_context *ldb, struct ldb_module *module)
280 while (module && module->ops->init_context == NULL)
281 module = module->next;
283 if (module && module->ops->init_context &&
284 module->ops->init_context(module) != LDB_SUCCESS) {
285 ldb_debug(ldb, LDB_DEBUG_FATAL, "module initialization failed\n");
286 return LDB_ERR_OPERATIONS_ERROR;
292 int ldb_load_modules(struct ldb_context *ldb, const char *options[])
294 const char **modules = NULL;
297 TALLOC_CTX *mem_ctx = talloc_new(ldb);
299 return LDB_ERR_OPERATIONS_ERROR;
302 /* find out which modules we are requested to activate */
304 /* check if we have a custom module list passd as ldb option */
306 for (i = 0; options[i] != NULL; i++) {
307 if (strncmp(options[i], LDB_MODULE_PREFIX, LDB_MODULE_PREFIX_LEN) == 0) {
308 modules = ldb_modules_list_from_string(ldb, mem_ctx, &options[i][LDB_MODULE_PREFIX_LEN]);
313 /* if not overloaded by options and the backend is not ldap try to load the modules list from ldb */
314 if ((modules == NULL) && (strcmp("ldap", ldb->modules->ops->name) != 0)) {
315 const char * const attrs[] = { "@LIST" , NULL};
316 struct ldb_result *res = NULL;
317 struct ldb_dn *mods_dn;
319 mods_dn = ldb_dn_explode(mem_ctx, "@MODULES");
320 if (mods_dn == NULL) {
321 talloc_free(mem_ctx);
325 ret = ldb_search(ldb, mods_dn, LDB_SCOPE_BASE, "", attrs, &res);
326 if (res) talloc_steal(mods_dn, res);
327 if (ret == LDB_SUCCESS && (res->count == 0 || res->msgs[0]->num_elements == 0)) {
328 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db\n");
330 if (ret != LDB_SUCCESS) {
331 ldb_debug(ldb, LDB_DEBUG_FATAL, "ldb error (%s) occurred searching for modules, bailing out\n", ldb_errstring(ldb));
332 talloc_free(mem_ctx);
335 if (res->count > 1) {
336 ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found (%d), bailing out\n", res->count);
337 talloc_free(mem_ctx);
341 modules = ldb_modules_list_from_string(ldb, mem_ctx,
342 (const char *)res->msgs[0]->elements[0].values[0].data);
346 talloc_free(mods_dn);
349 if (modules != NULL) {
350 ret = ldb_load_modules_list(ldb, modules, ldb->modules, &ldb->modules);
351 talloc_free(modules);
352 if (ret != LDB_SUCCESS) {
356 ldb_debug(ldb, LDB_DEBUG_TRACE, "No modules specified for this database\n");
359 return ldb_init_module_chain(ldb, ldb->modules);
363 by using this we allow ldb modules to only implement the functions they care about,
364 which makes writing a module simpler, and makes it more likely to keep working
367 #define FIND_OP(module, op) do { \
368 struct ldb_context *ldb = module->ldb; \
369 module = module->next; \
370 while (module && module->ops->op == NULL) module = module->next; \
371 if (module == NULL) { \
372 ldb_asprintf_errstring(ldb, "Unable to find backend operation for " #op ); \
373 return LDB_ERR_OPERATIONS_ERROR; \
379 helper functions to call the next module in chain
382 int ldb_next_request(struct ldb_module *module, struct ldb_request *request)
384 switch (request->operation) {
386 FIND_OP(module, search);
387 return module->ops->search(module, request);
389 FIND_OP(module, add);
390 return module->ops->add(module, request);
392 FIND_OP(module, modify);
393 return module->ops->modify(module, request);
395 FIND_OP(module, del);
396 return module->ops->del(module, request);
398 FIND_OP(module, rename);
399 return module->ops->rename(module, request);
400 case LDB_SEQUENCE_NUMBER:
401 FIND_OP(module, sequence_number);
402 return module->ops->sequence_number(module, request);
404 FIND_OP(module, request);
405 return module->ops->request(module, request);
409 int ldb_next_init(struct ldb_module *module)
411 /* init is different in that it is not an error if modules
412 * do not require initialization */
414 module = module->next;
416 while (module && module->ops->init_context == NULL)
417 module = module->next;
422 return module->ops->init_context(module);
425 int ldb_next_start_trans(struct ldb_module *module)
427 FIND_OP(module, start_transaction);
428 return module->ops->start_transaction(module);
431 int ldb_next_end_trans(struct ldb_module *module)
433 FIND_OP(module, end_transaction);
434 return module->ops->end_transaction(module);
437 int ldb_next_del_trans(struct ldb_module *module)
439 FIND_OP(module, del_transaction);
440 return module->ops->del_transaction(module);