source4/dsdb/samdb/ldb_modules/samba_dsdb.c

   1 /*
   2    Samba4 module loading module
   3
   4    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2009
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 /*
  21  *  Name: ldb
  22  *
  23  *  Component: Samba4 module loading module
  24  *
  25  *  Description: Implement a single 'module' in the ldb database,
  26  *  which loads the remaining modules based on 'choice of configuration' attributes
  27  *
  28  *  This is to avoid forcing a reprovision of the ldb databases when we change the internal structure of the code
  29  *
  30  *  Author: Andrew Bartlett
  31  */
  32
  33 #include "includes.h"
  34 #include <ldb.h>
  35 #include <ldb_errors.h>
  36 #include <ldb_module.h>
  37 #include "dsdb/samdb/ldb_modules/util.h"
  38 #include "dsdb/samdb/samdb.h"
  39 #include "librpc/ndr/libndr.h"
  40
  41 static int read_at_rootdse_record(struct ldb_context *ldb, struct ldb_module *module, TALLOC_CTX *mem_ctx,
  42                                   struct ldb_message **msg, struct ldb_request *parent)
  43 {
  44         int ret;
  45         static const char *rootdse_attrs[] = { "defaultNamingContext", "configurationNamingContext", "schemaNamingContext", NULL };
  46         struct ldb_result *rootdse_res;
  47         struct ldb_dn *rootdse_dn;
  48         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
  49         if (!tmp_ctx) {
  50                 return ldb_oom(ldb);
  51         }
  52
  53         rootdse_dn = ldb_dn_new(tmp_ctx, ldb, "@ROOTDSE");
  54         if (!rootdse_dn) {
  55                 talloc_free(tmp_ctx);
  56                 return ldb_oom(ldb);
  57         }
  58
  59         ret = dsdb_module_search_dn(module, tmp_ctx, &rootdse_res, rootdse_dn,
  60                                     rootdse_attrs, DSDB_FLAG_NEXT_MODULE, parent);
  61         if (ret != LDB_SUCCESS) {
  62                 talloc_free(tmp_ctx);
  63                 return ret;
  64         }
  65
  66         talloc_steal(mem_ctx, rootdse_res->msgs);
  67         *msg = rootdse_res->msgs[0];
  68
  69         talloc_free(tmp_ctx);
  70
  71         return ret;
  72 }
  73
  74 static int prepare_modules_line(struct ldb_context *ldb,
  75                                 TALLOC_CTX *mem_ctx,
  76                                 const struct ldb_message *rootdse_msg,
  77                                 struct ldb_message *msg, const char *backend_attr,
  78                                 const char *backend_mod, const char **backend_mod_list)
  79 {
  80         int ret;
  81         const char **backend_full_list;
  82         const char *backend_dn;
  83         char *mod_list_string;
  84         char *full_string;
  85         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
  86         if (!tmp_ctx) {
  87                 return ldb_oom(ldb);
  88         }
  89
  90         if (backend_attr) {
  91                 backend_dn = ldb_msg_find_attr_as_string(rootdse_msg, backend_attr, NULL);
  92                 if (!backend_dn) {
  93                         ldb_asprintf_errstring(ldb,
  94                                                "samba_dsdb_init: "
  95                                                "unable to read %s from %s:%s",
  96                                                backend_attr, ldb_dn_get_linearized(rootdse_msg->dn),
  97                                                ldb_errstring(ldb));
  98                         return LDB_ERR_CONSTRAINT_VIOLATION;
  99                 }
 100         } else {
 101                 backend_dn = "*";
 102         }
 103
 104         if (backend_mod) {
 105                 backend_full_list = (const char **)str_list_make_single(tmp_ctx, backend_mod);
 106         } else {
 107                 backend_full_list = (const char **)str_list_make_empty(tmp_ctx);
 108         }
 109         if (!backend_full_list) {
 110                 talloc_free(tmp_ctx);
 111                 return ldb_oom(ldb);
 112         }
 113
 114         backend_full_list = str_list_append_const(backend_full_list, backend_mod_list);
 115         if (!backend_full_list) {
 116                 talloc_free(tmp_ctx);
 117                 return ldb_oom(ldb);
 118         }
 119
 120         mod_list_string = str_list_join(tmp_ctx, backend_full_list, ',');
 121         if (!mod_list_string) {
 122                 talloc_free(tmp_ctx);
 123                 return ldb_oom(ldb);
 124         }
 125
 126         full_string = talloc_asprintf(tmp_ctx, "%s:%s", backend_dn, mod_list_string);
 127         ret = ldb_msg_add_steal_string(msg, "modules", full_string);
 128         talloc_free(tmp_ctx);
 129         return ret;
 130 }
 131
 132
 133
 134 static int samba_dsdb_init(struct ldb_module *module)
 135 {
 136         struct ldb_context *ldb = ldb_module_get_ctx(module);
 137         int ret, len, i;
 138         TALLOC_CTX *tmp_ctx = talloc_new(module);
 139         struct ldb_result *res;
 140         struct ldb_message *rootdse_msg, *partition_msg;
 141         struct ldb_dn *samba_dsdb_dn;
 142         struct ldb_module *backend_module, *module_chain;
 143         const char **final_module_list, **reverse_module_list;
 144         /*
 145           Add modules to the list to activate them by default
 146           beware often order is important
 147
 148           Some Known ordering constraints:
 149           - rootdse must be first, as it makes redirects from "" -> cn=rootdse
 150           - extended_dn_in must be before objectclass.c, as it resolves the DN
 151           - objectclass must be before password_hash and samldb since these LDB
 152             modules require the expanded "objectClass" list
 153           - objectclass must be before descriptor and acl, as both assume that
 154             objectClass values are sorted
 155           - objectclass_attrs must be behind operational in order to see all
 156             attributes (the operational module protects and therefore
 157             suppresses per default some important ones)
 158           - partition must be last
 159           - each partition has its own module list then
 160
 161           The list is presented here as a set of declarations to show the
 162           stack visually - the code below then handles the creation of the list
 163           based on the parameters loaded from the database.
 164         */
 165         static const char *modules_list[] = {"resolve_oids",
 166                                              "rootdse",
 167                                              "schema_load",
 168                                              "lazy_commit",
 169                                              "dirsync",
 170                                              "paged_results",
 171                                              "ranged_results",
 172                                              "anr",
 173                                              "server_sort",
 174                                              "asq",
 175                                              "extended_dn_store",
 176                                              "extended_dn_in",
 177                                              "objectclass",
 178                                              "descriptor",
 179                                              "acl",
 180                                              "aclread",
 181                                              "samldb",
 182                                              "password_hash",
 183                                              "operational",
 184                                              "instancetype",
 185                                              "objectclass_attrs",
 186                                              NULL };
 187
 188         const char **link_modules;
 189         static const char *fedora_ds_modules[] = {
 190                 "rdn_name", NULL };
 191         static const char *openldap_modules[] = {
 192                 NULL };
 193         static const char *tdb_modules_list[] = {
 194                 "rdn_name",
 195                 "subtree_delete",
 196                 "repl_meta_data",
 197                 "subtree_rename",
 198                 "linked_attributes",
 199                 NULL};
 200
 201         const char *extended_dn_module;
 202         const char *extended_dn_module_ldb = "extended_dn_out_ldb";
 203         const char *extended_dn_module_fds = "extended_dn_out_fds";
 204         const char *extended_dn_module_openldap = "extended_dn_out_openldap";
 205
 206         static const char *modules_list2[] = {"show_deleted",
 207                                               "new_partition",
 208                                               "partition",
 209                                               NULL };
 210
 211         const char **backend_modules;
 212         static const char *fedora_ds_backend_modules[] = {
 213                 "nsuniqueid", "paged_searches", "simple_dn", NULL };
 214         static const char *openldap_backend_modules[] = {
 215                 "entryuuid", "paged_searches", "simple_dn", NULL };
 216
 217         static const char *samba_dsdb_attrs[] = { "backendType", NULL };
 218         const char *backendType;
 219
 220         if (!tmp_ctx) {
 221                 return ldb_oom(ldb);
 222         }
 223
 224         ret = ldb_register_samba_handlers(ldb);
 225         if (ret != LDB_SUCCESS) {
 226                 talloc_free(tmp_ctx);
 227                 return ret;
 228         }
 229
 230         samba_dsdb_dn = ldb_dn_new(tmp_ctx, ldb, "@SAMBA_DSDB");
 231         if (!samba_dsdb_dn) {
 232                 talloc_free(tmp_ctx);
 233                 return ldb_oom(ldb);
 234         }
 235
 236 #define CHECK_LDB_RET(check_ret)                                \
 237         do {                                                    \
 238                 if (check_ret != LDB_SUCCESS) {                 \
 239                         talloc_free(tmp_ctx);                   \
 240                         return check_ret;                       \
 241                 }                                               \
 242         } while (0)
 243
 244         ret = dsdb_module_search_dn(module, tmp_ctx, &res, samba_dsdb_dn,
 245                                     samba_dsdb_attrs, DSDB_FLAG_NEXT_MODULE, NULL);
 246         if (ret == LDB_ERR_NO_SUCH_OBJECT) {
 247                 backendType = "ldb";
 248         } else if (ret == LDB_SUCCESS) {
 249                 backendType = ldb_msg_find_attr_as_string(res->msgs[0], "backendType", "ldb");
 250         } else {
 251                 talloc_free(tmp_ctx);
 252                 return ret;
 253         }
 254
 255         backend_modules = NULL;
 256         if (strcasecmp(backendType, "ldb") == 0) {
 257                 extended_dn_module = extended_dn_module_ldb;
 258                 link_modules = tdb_modules_list;
 259         } else {
 260                 if (strcasecmp(backendType, "fedora-ds") == 0) {
 261                         link_modules = fedora_ds_modules;
 262                         backend_modules = fedora_ds_backend_modules;
 263                         extended_dn_module = extended_dn_module_fds;
 264                 } else if (strcasecmp(backendType, "openldap") == 0) {
 265                         link_modules = openldap_modules;
 266                         backend_modules = openldap_backend_modules;
 267                         extended_dn_module = extended_dn_module_openldap;
 268                 } else {
 269                         return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR, "invalid backend type");
 270                 }
 271                 ret = ldb_set_opaque(ldb, "readOnlySchema", (void*)1);
 272                 if (ret != LDB_SUCCESS) {
 273                         ldb_set_errstring(ldb, "Failed to set readOnlySchema opaque");
 274                 }
 275         }
 276
 277 #define CHECK_MODULE_LIST \
 278         do {                                                    \
 279                 if (!final_module_list) {                       \
 280                         talloc_free(tmp_ctx);                   \
 281                         return ldb_oom(ldb);                    \
 282                 }                                               \
 283         } while (0)
 284
 285         final_module_list = str_list_copy_const(tmp_ctx, modules_list);
 286         CHECK_MODULE_LIST;
 287
 288         final_module_list = str_list_append_const(final_module_list, link_modules);
 289         CHECK_MODULE_LIST;
 290
 291         final_module_list = str_list_add_const(final_module_list, extended_dn_module);
 292         CHECK_MODULE_LIST;
 293
 294         final_module_list = str_list_append_const(final_module_list, modules_list2);
 295         CHECK_MODULE_LIST;
 296
 297
 298         ret = read_at_rootdse_record(ldb, module, tmp_ctx, &rootdse_msg, NULL);
 299         CHECK_LDB_RET(ret);
 300
 301         partition_msg = ldb_msg_new(tmp_ctx);
 302         partition_msg->dn = ldb_dn_new(partition_msg, ldb, "@" DSDB_OPAQUE_PARTITION_MODULE_MSG_OPAQUE_NAME);
 303
 304         ret = prepare_modules_line(ldb, tmp_ctx,
 305                                    rootdse_msg,
 306                                    partition_msg, "schemaNamingContext",
 307                                    "schema_data", backend_modules);
 308         CHECK_LDB_RET(ret);
 309
 310         ret = prepare_modules_line(ldb, tmp_ctx,
 311                                    rootdse_msg,
 312                                    partition_msg, NULL,
 313                                    NULL, backend_modules);
 314         CHECK_LDB_RET(ret);
 315
 316         ret = ldb_set_opaque(ldb, DSDB_OPAQUE_PARTITION_MODULE_MSG_OPAQUE_NAME, partition_msg);
 317         CHECK_LDB_RET(ret);
 318
 319         talloc_steal(ldb, partition_msg);
 320
 321         /* Now prepare the module chain.  Oddly, we must give it to ldb_load_modules_list in REVERSE */
 322         for (len = 0; final_module_list[len]; len++) { /* noop */};
 323
 324         reverse_module_list = talloc_array(tmp_ctx, const char *, len+1);
 325         if (!reverse_module_list) {
 326                 talloc_free(tmp_ctx);
 327                 return ldb_oom(ldb);
 328         }
 329         for (i=0; i < len; i++) {
 330                 reverse_module_list[i] = final_module_list[(len - 1) - i];
 331         }
 332         reverse_module_list[i] = NULL;
 333
 334         /* The backend (at least until the partitions module
 335          * reconfigures things) is the next module in the currently
 336          * loaded chain */
 337         backend_module = ldb_module_next(module);
 338         ret = ldb_module_load_list(ldb, reverse_module_list, backend_module, &module_chain);
 339         CHECK_LDB_RET(ret);
 340
 341         talloc_free(tmp_ctx);
 342         /* Set this as the 'next' module, so that we effectivly append it to module chain */
 343         ldb_module_set_next(module, module_chain);
 344
 345         return ldb_next_init(module);
 346 }
 347
 348 static const struct ldb_module_ops ldb_samba_dsdb_module_ops = {
 349         .name              = "samba_dsdb",
 350         .init_context      = samba_dsdb_init,
 351 };
 352
 353 int ldb_samba_dsdb_module_init(const char *version)
 354 {
 355         LDB_MODULE_CHECK_VERSION(version);
 356         return ldb_register_module(&ldb_samba_dsdb_module_ops);
 357 }