4 Copyright (C) Simo Sorce 2004
6 ** NOTE! The following LGPL license applies to the ldb
7 ** library. This does NOT imply that all of Samba is released
10 This library is free software; you can redistribute it and/or
11 modify it under the terms of the GNU Lesser General Public
12 License as published by the Free Software Foundation; either
13 version 3 of the License, or (at your option) any later version.
15 This library is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 Lesser General Public License for more details.
20 You should have received a copy of the GNU Lesser General Public
21 License along with this library; if not, see <http://www.gnu.org/licenses/>.
27 * Component: ldb modules core
29 * Description: core modules routines
34 #include "ldb_includes.h"
36 #if (_SAMBA_BUILD_ >= 4)
40 #define LDB_MODULE_PREFIX "modules:"
41 #define LDB_MODULE_PREFIX_LEN 8
43 void ldb_set_modules_dir(struct ldb_context *ldb, const char *path)
45 talloc_free(ldb->modules_dir);
46 ldb->modules_dir = talloc_strdup(ldb, path);
49 static char *ldb_modules_strdup_no_spaces(TALLOC_CTX *mem_ctx, const char *string)
54 trimmed = talloc_strdup(mem_ctx, string);
59 len = strlen(trimmed);
60 for (i = 0; trimmed[i] != '\0'; i++) {
65 memmove(&trimmed[i], &trimmed[i + 1], len -i -1);
74 /* modules are called in inverse order on the stack.
75 Lets place them as an admin would think the right order is.
76 Modules order is important */
77 const char **ldb_modules_list_from_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *string)
79 char **modules = NULL;
84 /* spaces not admitted */
85 modstr = ldb_modules_strdup_no_spaces(mem_ctx, string);
87 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_strdup_no_spaces()\n");
91 modules = talloc_realloc(mem_ctx, modules, char *, 2);
93 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
97 talloc_steal(modules, modstr);
100 /* The str*r*chr walks backwards: This is how we get the inverse order mentioned above */
101 while ((p = strrchr(modstr, ',')) != NULL) {
107 modules = talloc_realloc(mem_ctx, modules, char *, i + 2);
109 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
116 modules[i + 1] = NULL;
118 m = (const char **)modules;
123 static struct ops_list_entry {
124 const struct ldb_module_ops *ops;
125 struct ops_list_entry *next;
126 } *registered_modules = NULL;
128 #ifndef STATIC_LIBLDB_MODULES
130 #define STATIC_LIBLDB_MODULES \
131 ldb_operational_module_ops, \
132 ldb_rdn_name_module_ops, \
133 ldb_paged_results_module_ops, \
134 ldb_sort_module_ops, \
135 ldb_asq_module_ops, \
139 const static struct ldb_module_ops *builtin_modules[] = {
140 STATIC_LIBLDB_MODULES
143 static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
145 struct ops_list_entry *e;
148 for (i = 0; builtin_modules[i]; i++) {
149 if (strcmp(builtin_modules[i]->name, name) == 0)
150 return builtin_modules[i];
153 for (e = registered_modules; e; e = e->next) {
154 if (strcmp(e->ops->name, name) == 0)
162 int ldb_register_module(const struct ldb_module_ops *ops)
164 struct ops_list_entry *entry = talloc(talloc_autofree_context(), struct ops_list_entry);
166 if (ldb_find_module_ops(ops->name) != NULL)
173 entry->next = registered_modules;
174 registered_modules = entry;
179 void *ldb_dso_load_symbol(struct ldb_context *ldb, const char *name,
186 if (ldb->modules_dir == NULL)
189 path = talloc_asprintf(ldb, "%s/%s.%s", ldb->modules_dir, name,
192 ldb_debug(ldb, LDB_DEBUG_TRACE, "trying to load %s from %s\n", name, path);
194 handle = dlopen(path, RTLD_NOW);
195 if (handle == NULL) {
196 ldb_debug(ldb, LDB_DEBUG_WARNING, "unable to load %s from %s: %s\n", name, path, dlerror());
200 sym = (int (*)(void))dlsym(handle, symbol);
203 ldb_debug(ldb, LDB_DEBUG_ERROR, "no symbol `%s' found in %s: %s\n", symbol, path, dlerror());
212 int ldb_load_modules_list(struct ldb_context *ldb, const char **module_list, struct ldb_module *backend, struct ldb_module **out)
214 struct ldb_module *module;
219 for (i = 0; module_list[i] != NULL; i++) {
220 struct ldb_module *current;
221 const struct ldb_module_ops *ops;
223 ops = ldb_find_module_ops(module_list[i]);
225 int (*init_fn) (void);
227 init_fn = ldb_dso_load_symbol(ldb, module_list[i],
229 if (init_fn != NULL && init_fn() == 0) {
230 ops = ldb_find_module_ops(module_list[i]);
235 char *symbol_name = talloc_asprintf(ldb, "ldb_%s_module_ops",
237 if (symbol_name == NULL) {
238 return LDB_ERR_OPERATIONS_ERROR;
240 ops = ldb_dso_load_symbol(ldb, module_list[i], symbol_name);
241 talloc_free(symbol_name);
245 ldb_debug(ldb, LDB_DEBUG_WARNING, "WARNING: Module [%s] not found\n",
250 current = talloc_zero(ldb, struct ldb_module);
251 if (current == NULL) {
252 return LDB_ERR_OPERATIONS_ERROR;
254 talloc_set_name(current, "ldb_module: %s", module_list[i]);
259 DLIST_ADD(module, current);
265 int ldb_init_module_chain(struct ldb_context *ldb, struct ldb_module *module)
267 while (module && module->ops->init_context == NULL)
268 module = module->next;
270 /* init is different in that it is not an error if modules
271 * do not require initialization */
274 int ret = module->ops->init_context(module);
275 if (ret != LDB_SUCCESS) {
276 ldb_debug(ldb, LDB_DEBUG_FATAL, "module %s initialization failed\n", module->ops->name);
284 int ldb_load_modules(struct ldb_context *ldb, const char *options[])
286 const char **modules = NULL;
289 TALLOC_CTX *mem_ctx = talloc_new(ldb);
291 return LDB_ERR_OPERATIONS_ERROR;
294 /* find out which modules we are requested to activate */
296 /* check if we have a custom module list passd as ldb option */
298 for (i = 0; options[i] != NULL; i++) {
299 if (strncmp(options[i], LDB_MODULE_PREFIX, LDB_MODULE_PREFIX_LEN) == 0) {
300 modules = ldb_modules_list_from_string(ldb, mem_ctx, &options[i][LDB_MODULE_PREFIX_LEN]);
305 /* if not overloaded by options and the backend is not ldap try to load the modules list from ldb */
306 if ((modules == NULL) && (strcmp("ldap", ldb->modules->ops->name) != 0)) {
307 const char * const attrs[] = { "@LIST" , NULL};
308 struct ldb_result *res = NULL;
309 struct ldb_dn *mods_dn;
311 mods_dn = ldb_dn_new(mem_ctx, ldb, "@MODULES");
312 if (mods_dn == NULL) {
313 talloc_free(mem_ctx);
317 ret = ldb_search_exp_fmt(ldb, mods_dn, &res, mods_dn, LDB_SCOPE_BASE, attrs, "@LIST=*");
319 if (ret == LDB_ERR_NO_SUCH_OBJECT) {
320 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
321 } else if (ret != LDB_SUCCESS) {
322 ldb_debug(ldb, LDB_DEBUG_FATAL, "ldb error (%s) occurred searching for modules, bailing out\n", ldb_errstring(ldb));
323 talloc_free(mem_ctx);
326 const char *module_list;
327 if (res->count == 0) {
328 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
329 } else if (res->count > 1) {
330 ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found (%d), bailing out\n", res->count);
331 talloc_free(mem_ctx);
334 module_list = ldb_msg_find_attr_as_string(res->msgs[0], "@LIST", NULL);
336 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
338 modules = ldb_modules_list_from_string(ldb, mem_ctx,
343 talloc_free(mods_dn);
346 if (modules != NULL) {
347 ret = ldb_load_modules_list(ldb, modules, ldb->modules, &ldb->modules);
348 if (ret != LDB_SUCCESS) {
349 talloc_free(mem_ctx);
353 ldb_debug(ldb, LDB_DEBUG_TRACE, "No modules specified for this database");
356 ret = ldb_init_module_chain(ldb, ldb->modules);
357 talloc_free(mem_ctx);
362 by using this we allow ldb modules to only implement the functions they care about,
363 which makes writing a module simpler, and makes it more likely to keep working
366 #define FIND_OP(module, op) do { \
367 struct ldb_context *ldb = module->ldb; \
368 module = module->next; \
369 while (module && module->ops->op == NULL) module = module->next; \
370 if (module == NULL) { \
371 ldb_asprintf_errstring(ldb, "Unable to find backend operation for " #op ); \
372 return LDB_ERR_OPERATIONS_ERROR; \
378 helper functions to call the next module in chain
381 int ldb_next_request(struct ldb_module *module, struct ldb_request *request)
384 switch (request->operation) {
386 FIND_OP(module, search);
387 ret = module->ops->search(module, request);
390 FIND_OP(module, add);
391 ret = module->ops->add(module, request);
394 FIND_OP(module, modify);
395 ret = module->ops->modify(module, request);
398 FIND_OP(module, del);
399 ret = module->ops->del(module, request);
402 FIND_OP(module, rename);
403 ret = module->ops->rename(module, request);
406 FIND_OP(module, extended);
407 ret = module->ops->extended(module, request);
409 case LDB_SEQUENCE_NUMBER:
410 FIND_OP(module, sequence_number);
411 ret = module->ops->sequence_number(module, request);
414 FIND_OP(module, request);
415 ret = module->ops->request(module, request);
418 if (ret == LDB_SUCCESS) {
421 if (!ldb_errstring(module->ldb)) {
422 /* Set a default error string, to place the blame somewhere */
423 ldb_asprintf_errstring(module->ldb, "error in module %s: %s (%d)", module->ops->name, ldb_strerror(ret), ret);
428 int ldb_next_init(struct ldb_module *module)
430 module = module->next;
432 return ldb_init_module_chain(module->ldb, module);
435 int ldb_next_start_trans(struct ldb_module *module)
437 FIND_OP(module, start_transaction);
438 return module->ops->start_transaction(module);
441 int ldb_next_end_trans(struct ldb_module *module)
443 FIND_OP(module, end_transaction);
444 return module->ops->end_transaction(module);
447 int ldb_next_del_trans(struct ldb_module *module)
449 FIND_OP(module, del_transaction);
450 return module->ops->del_transaction(module);