source4/dsdb/samdb/ldb_modules/objectguid.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
   5    Copyright (C) Andrew Tridgell 2005
   6    Copyright (C) Simo Sorce  2004-2008
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 /*
  23  *  Name: ldb
  24  *
  25  *  Component: ldb objectguid module
  26  *
  27  *  Description: add a unique objectGUID onto every new record
  28  *
  29  *  Author: Simo Sorce
  30  */
  31
  32 #include "includes.h"
  33 #include "ldb_module.h"
  34 #include "dsdb/samdb/samdb.h"
  35 #include "dsdb/samdb/ldb_modules/util.h"
  36 #include "librpc/gen_ndr/ndr_misc.h"
  37 #include "param/param.h"
  38
  39 /*
  40   add a time element to a record
  41 */
  42 static int add_time_element(struct ldb_message *msg, const char *attr, time_t t)
  43 {
  44         char *s;
  45         int ret;
  46
  47         if (ldb_msg_find_element(msg, attr) != NULL) {
  48                 return LDB_SUCCESS;
  49         }
  50
  51         s = ldb_timestring(msg, t);
  52         if (s == NULL) {
  53                 return LDB_ERR_OPERATIONS_ERROR;
  54         }
  55
  56         /* always set as replace. This works because on add ops, the flag
  57            is ignored */
  58         ret = ldb_msg_append_string(msg, attr, s, LDB_FLAG_MOD_REPLACE);
  59         if (ret != LDB_SUCCESS) {
  60                 return ret;
  61         }
  62
  63         return LDB_SUCCESS;
  64 }
  65
  66 /*
  67   add a uint64_t element to a record
  68 */
  69 static int add_uint64_element(struct ldb_context *ldb, struct ldb_message *msg,
  70                               const char *attr, uint64_t v)
  71 {
  72         int ret;
  73
  74         if (ldb_msg_find_element(msg, attr) != NULL) {
  75                 return LDB_SUCCESS;
  76         }
  77
  78         /* always set as replace. This works because on add ops, the flag
  79            is ignored */
  80         ret = samdb_msg_append_uint64(ldb, msg, msg, attr, v, LDB_FLAG_MOD_REPLACE);
  81         if (ret != LDB_SUCCESS) {
  82                 return ret;
  83         }
  84
  85         return LDB_SUCCESS;
  86 }
  87
  88 struct og_context {
  89         struct ldb_module *module;
  90         struct ldb_request *req;
  91 };
  92
  93 /* add_record: add objectGUID and timestamp attributes */
  94 static int objectguid_add(struct ldb_module *module, struct ldb_request *req)
  95 {
  96         struct ldb_context *ldb;
  97         struct ldb_request *down_req;
  98         struct ldb_message *msg;
  99         struct ldb_message_element *el;
 100         struct GUID guid;
 101         uint64_t seq_num;
 102         int ret;
 103         time_t t = time(NULL);
 104         struct og_context *ac;
 105
 106         ldb = ldb_module_get_ctx(module);
 107
 108         ldb_debug(ldb, LDB_DEBUG_TRACE, "objectguid_add_record\n");
 109
 110         /* do not manipulate our control entries */
 111         if (ldb_dn_is_special(req->op.add.message->dn)) {
 112                 return ldb_next_request(module, req);
 113         }
 114
 115         el = ldb_msg_find_element(req->op.add.message, "objectGUID");
 116         if (el != NULL) {
 117                 ldb_set_errstring(ldb,
 118                                   "objectguid: objectGUID must not be specified!");
 119                 return LDB_ERR_UNWILLING_TO_PERFORM;
 120         }
 121
 122         ac = talloc(req, struct og_context);
 123         if (ac == NULL) {
 124                 return ldb_oom(ldb);
 125         }
 126         ac->module = module;
 127         ac->req = req;
 128
 129         /* we have to copy the message as the caller might have it as a const */
 130         msg = ldb_msg_copy_shallow(ac, req->op.add.message);
 131         if (msg == NULL) {
 132                 talloc_free(ac);
 133                 return ldb_operr(ldb);
 134         }
 135
 136         /* a new GUID */
 137         guid = GUID_random();
 138
 139         ret = dsdb_msg_add_guid(msg, &guid, "objectGUID");
 140         if (ret != LDB_SUCCESS) {
 141                 return ret;
 142         }
 143
 144         if (add_time_element(msg, "whenCreated", t) != LDB_SUCCESS ||
 145             add_time_element(msg, "whenChanged", t) != LDB_SUCCESS) {
 146                 return ldb_operr(ldb);
 147         }
 148
 149         /* Get a sequence number from the backend */
 150         ret = ldb_sequence_number(ldb, LDB_SEQ_NEXT, &seq_num);
 151         if (ret == LDB_SUCCESS) {
 152                 if (add_uint64_element(ldb, msg, "uSNCreated",
 153                                        seq_num) != LDB_SUCCESS ||
 154                     add_uint64_element(ldb, msg, "uSNChanged",
 155                                        seq_num) != LDB_SUCCESS) {
 156                         return ldb_operr(ldb);
 157                 }
 158         }
 159
 160         ret = ldb_build_add_req(&down_req, ldb, ac,
 161                                 msg,
 162                                 req->controls,
 163                                 req, dsdb_next_callback,
 164                                 req);
 165         LDB_REQ_SET_LOCATION(down_req);
 166         if (ret != LDB_SUCCESS) {
 167                 return ret;
 168         }
 169
 170         /* go on with the call chain */
 171         return ldb_next_request(module, down_req);
 172 }
 173
 174 /* modify_record: update timestamps */
 175 static int objectguid_modify(struct ldb_module *module, struct ldb_request *req)
 176 {
 177         struct ldb_context *ldb;
 178         struct ldb_request *down_req;
 179         struct ldb_message *msg;
 180         struct ldb_message_element *el;
 181         int ret;
 182         time_t t = time(NULL);
 183         uint64_t seq_num;
 184         struct og_context *ac;
 185
 186         ldb = ldb_module_get_ctx(module);
 187
 188         ldb_debug(ldb, LDB_DEBUG_TRACE, "objectguid_modify_record\n");
 189
 190         /* do not manipulate our control entries */
 191         if (ldb_dn_is_special(req->op.mod.message->dn)) {
 192                 return ldb_next_request(module, req);
 193         }
 194
 195         el = ldb_msg_find_element(req->op.mod.message, "objectGUID");
 196         if (el != NULL) {
 197                 ldb_set_errstring(ldb,
 198                                   "objectguid: objectGUID must not be specified!");
 199                 return LDB_ERR_CONSTRAINT_VIOLATION;
 200         }
 201
 202         ac = talloc(req, struct og_context);
 203         if (ac == NULL) {
 204                 return ldb_oom(ldb);
 205         }
 206         ac->module = module;
 207         ac->req = req;
 208
 209         /* we have to copy the message as the caller might have it as a const */
 210         msg = ldb_msg_copy_shallow(ac, req->op.mod.message);
 211         if (msg == NULL) {
 212                 return ldb_operr(ldb);
 213         }
 214
 215         if (add_time_element(msg, "whenChanged", t) != LDB_SUCCESS) {
 216                 return ldb_operr(ldb);
 217         }
 218
 219         /* Get a sequence number from the backend */
 220         ret = ldb_sequence_number(ldb, LDB_SEQ_NEXT, &seq_num);
 221         if (ret == LDB_SUCCESS) {
 222                 if (add_uint64_element(ldb, msg, "uSNChanged",
 223                                        seq_num) != LDB_SUCCESS) {
 224                         return ldb_operr(ldb);
 225                 }
 226         }
 227
 228         ret = ldb_build_mod_req(&down_req, ldb, ac,
 229                                 msg,
 230                                 req->controls,
 231                                 req, dsdb_next_callback,
 232                                 req);
 233         LDB_REQ_SET_LOCATION(down_req);
 234         if (ret != LDB_SUCCESS) {
 235                 return ret;
 236         }
 237
 238         /* go on with the call chain */
 239         return ldb_next_request(module, down_req);
 240 }
 241
 242 static const struct ldb_module_ops ldb_objectguid_module_ops = {
 243         .name          = "objectguid",
 244         .add           = objectguid_add,
 245         .modify        = objectguid_modify
 246 };
 247
 248 int ldb_objectguid_module_init(const char *version)
 249 {
 250         LDB_MODULE_CHECK_VERSION(version);
 251         return ldb_register_module(&ldb_objectguid_module_ops);
 252 }