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 #define LDB_MODULE(name) (&ldb_ ## name ## _module_ops)
130 #ifndef STATIC_LIBLDB_MODULES
132 #define STATIC_LIBLDB_MODULES \
133 LDB_MODULE(operational), \
134 LDB_MODULE(rdn_name), \
135 LDB_MODULE(paged_results), \
136 LDB_MODULE(server_sort), \
141 const static struct ldb_module_ops *builtin_modules[] = {
142 STATIC_LIBLDB_MODULES
145 static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
147 struct ops_list_entry *e;
150 for (i = 0; builtin_modules[i]; i++) {
151 if (strcmp(builtin_modules[i]->name, name) == 0)
152 return builtin_modules[i];
155 for (e = registered_modules; e; e = e->next) {
156 if (strcmp(e->ops->name, name) == 0)
164 int ldb_register_module(const struct ldb_module_ops *ops)
166 struct ops_list_entry *entry = talloc(talloc_autofree_context(), struct ops_list_entry);
168 if (ldb_find_module_ops(ops->name) != NULL)
175 entry->next = registered_modules;
176 registered_modules = entry;
181 void *ldb_dso_load_symbol(struct ldb_context *ldb, const char *name,
188 if (ldb->modules_dir == NULL)
191 path = talloc_asprintf(ldb, "%s/%s.%s", ldb->modules_dir, name,
194 ldb_debug(ldb, LDB_DEBUG_TRACE, "trying to load %s from %s\n", name, path);
196 handle = dlopen(path, RTLD_NOW);
197 if (handle == NULL) {
198 ldb_debug(ldb, LDB_DEBUG_WARNING, "unable to load %s from %s: %s\n", name, path, dlerror());
202 sym = (int (*)(void))dlsym(handle, symbol);
205 ldb_debug(ldb, LDB_DEBUG_ERROR, "no symbol `%s' found in %s: %s\n", symbol, path, dlerror());
214 int ldb_load_modules_list(struct ldb_context *ldb, const char **module_list, struct ldb_module *backend, struct ldb_module **out)
216 struct ldb_module *module;
221 for (i = 0; module_list[i] != NULL; i++) {
222 struct ldb_module *current;
223 const struct ldb_module_ops *ops;
225 ops = ldb_find_module_ops(module_list[i]);
227 char *symbol_name = talloc_asprintf(ldb, "ldb_%s_module_ops",
229 if (symbol_name == NULL) {
230 return LDB_ERR_OPERATIONS_ERROR;
232 ops = ldb_dso_load_symbol(ldb, module_list[i], symbol_name);
233 talloc_free(symbol_name);
237 ldb_debug(ldb, LDB_DEBUG_WARNING, "WARNING: Module [%s] not found\n",
242 current = talloc_zero(ldb, struct ldb_module);
243 if (current == NULL) {
244 return LDB_ERR_OPERATIONS_ERROR;
246 talloc_set_name(current, "ldb_module: %s", module_list[i]);
251 DLIST_ADD(module, current);
257 int ldb_init_module_chain(struct ldb_context *ldb, struct ldb_module *module)
259 while (module && module->ops->init_context == NULL)
260 module = module->next;
262 /* init is different in that it is not an error if modules
263 * do not require initialization */
266 int ret = module->ops->init_context(module);
267 if (ret != LDB_SUCCESS) {
268 ldb_debug(ldb, LDB_DEBUG_FATAL, "module %s initialization failed\n", module->ops->name);
276 int ldb_load_modules(struct ldb_context *ldb, const char *options[])
278 const char **modules = NULL;
281 TALLOC_CTX *mem_ctx = talloc_new(ldb);
283 return LDB_ERR_OPERATIONS_ERROR;
286 /* find out which modules we are requested to activate */
288 /* check if we have a custom module list passd as ldb option */
290 for (i = 0; options[i] != NULL; i++) {
291 if (strncmp(options[i], LDB_MODULE_PREFIX, LDB_MODULE_PREFIX_LEN) == 0) {
292 modules = ldb_modules_list_from_string(ldb, mem_ctx, &options[i][LDB_MODULE_PREFIX_LEN]);
297 /* if not overloaded by options and the backend is not ldap try to load the modules list from ldb */
298 if ((modules == NULL) && (strcmp("ldap", ldb->modules->ops->name) != 0)) {
299 const char * const attrs[] = { "@LIST" , NULL};
300 struct ldb_result *res = NULL;
301 struct ldb_dn *mods_dn;
303 mods_dn = ldb_dn_new(mem_ctx, ldb, "@MODULES");
304 if (mods_dn == NULL) {
305 talloc_free(mem_ctx);
309 ret = ldb_search_exp_fmt(ldb, mods_dn, &res, mods_dn, LDB_SCOPE_BASE, attrs, "@LIST=*");
311 if (ret == LDB_ERR_NO_SUCH_OBJECT) {
312 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
313 } else if (ret != LDB_SUCCESS) {
314 ldb_debug(ldb, LDB_DEBUG_FATAL, "ldb error (%s) occurred searching for modules, bailing out\n", ldb_errstring(ldb));
315 talloc_free(mem_ctx);
318 const char *module_list;
319 if (res->count == 0) {
320 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
321 } else if (res->count > 1) {
322 ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found (%d), bailing out\n", res->count);
323 talloc_free(mem_ctx);
326 module_list = ldb_msg_find_attr_as_string(res->msgs[0], "@LIST", NULL);
328 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
330 modules = ldb_modules_list_from_string(ldb, mem_ctx,
335 talloc_free(mods_dn);
338 if (modules != NULL) {
339 ret = ldb_load_modules_list(ldb, modules, ldb->modules, &ldb->modules);
340 if (ret != LDB_SUCCESS) {
341 talloc_free(mem_ctx);
345 ldb_debug(ldb, LDB_DEBUG_TRACE, "No modules specified for this database");
348 ret = ldb_init_module_chain(ldb, ldb->modules);
349 talloc_free(mem_ctx);
354 by using this we allow ldb modules to only implement the functions they care about,
355 which makes writing a module simpler, and makes it more likely to keep working
358 #define FIND_OP(module, op) do { \
359 struct ldb_context *ldb = module->ldb; \
360 module = module->next; \
361 while (module && module->ops->op == NULL) module = module->next; \
362 if (module == NULL) { \
363 ldb_asprintf_errstring(ldb, "Unable to find backend operation for " #op ); \
364 return LDB_ERR_OPERATIONS_ERROR; \
370 helper functions to call the next module in chain
373 int ldb_next_request(struct ldb_module *module, struct ldb_request *request)
376 switch (request->operation) {
378 FIND_OP(module, search);
379 ret = module->ops->search(module, request);
382 FIND_OP(module, add);
383 ret = module->ops->add(module, request);
386 FIND_OP(module, modify);
387 ret = module->ops->modify(module, request);
390 FIND_OP(module, del);
391 ret = module->ops->del(module, request);
394 FIND_OP(module, rename);
395 ret = module->ops->rename(module, request);
398 FIND_OP(module, extended);
399 ret = module->ops->extended(module, request);
401 case LDB_SEQUENCE_NUMBER:
402 FIND_OP(module, sequence_number);
403 ret = module->ops->sequence_number(module, request);
406 FIND_OP(module, request);
407 ret = module->ops->request(module, request);
410 if (ret == LDB_SUCCESS) {
413 if (!ldb_errstring(module->ldb)) {
414 /* Set a default error string, to place the blame somewhere */
415 ldb_asprintf_errstring(module->ldb, "error in module %s: %s (%d)", module->ops->name, ldb_strerror(ret), ret);
420 int ldb_next_init(struct ldb_module *module)
422 module = module->next;
424 return ldb_init_module_chain(module->ldb, module);
427 int ldb_next_start_trans(struct ldb_module *module)
429 FIND_OP(module, start_transaction);
430 return module->ops->start_transaction(module);
433 int ldb_next_end_trans(struct ldb_module *module)
435 FIND_OP(module, end_transaction);
436 return module->ops->end_transaction(module);
439 int ldb_next_del_trans(struct ldb_module *module)
441 FIND_OP(module, del_transaction);
442 return module->ops->del_transaction(module);