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         struct ldb_message_element *el;
  45         char *s;
  46         int ret;
  47
  48         if (ldb_msg_find_element(msg, attr) != NULL) {
  49                 return LDB_SUCCESS;
  50         }
  51
  52         s = ldb_timestring(msg, t);
  53         if (s == NULL) {
  54                 return LDB_ERR_OPERATIONS_ERROR;
  55         }
  56
  57         ret = ldb_msg_add_string(msg, attr, s);
  58         if (ret != LDB_SUCCESS) {
  59                 return ret;
  60         }
  61
  62         el = ldb_msg_find_element(msg, attr);
  63         /* always set as replace. This works because on add ops, the flag
  64            is ignored */
  65         el->flags = LDB_FLAG_MOD_REPLACE;
  66
  67         return LDB_SUCCESS;
  68 }
  69
  70 /*
  71   add a uint64_t element to a record
  72 */
  73 static int add_uint64_element(struct ldb_context *ldb, struct ldb_message *msg,
  74                               const char *attr, uint64_t v)
  75 {
  76         struct ldb_message_element *el;
  77         int ret;
  78
  79         if (ldb_msg_find_element(msg, attr) != NULL) {
  80                 return LDB_SUCCESS;
  81         }
  82
  83         ret = samdb_msg_add_uint64(ldb, msg, msg, attr, v);
  84         if (ret != LDB_SUCCESS) {
  85                 return ret;
  86         }
  87
  88         el = ldb_msg_find_element(msg, attr);
  89         /* always set as replace. This works because on add ops, the flag
  90            is ignored */
  91         el->flags = LDB_FLAG_MOD_REPLACE;
  92
  93         return LDB_SUCCESS;
  94 }
  95
  96 struct og_context {
  97         struct ldb_module *module;
  98         struct ldb_request *req;
  99 };
 100
 101 /* add_record: add objectGUID and timestamp attributes */
 102 static int objectguid_add(struct ldb_module *module, struct ldb_request *req)
 103 {
 104         struct ldb_context *ldb;
 105         struct ldb_request *down_req;
 106         struct ldb_message *msg;
 107         struct ldb_message_element *el;
 108         struct GUID guid;
 109         uint64_t seq_num;
 110         int ret;
 111         time_t t = time(NULL);
 112         struct og_context *ac;
 113
 114         ldb = ldb_module_get_ctx(module);
 115
 116         ldb_debug(ldb, LDB_DEBUG_TRACE, "objectguid_add_record\n");
 117
 118         /* do not manipulate our control entries */
 119         if (ldb_dn_is_special(req->op.add.message->dn)) {
 120                 return ldb_next_request(module, req);
 121         }
 122
 123         el = ldb_msg_find_element(req->op.add.message, "objectGUID");
 124         if (el != NULL) {
 125                 ldb_set_errstring(ldb,
 126                                   "objectguid: objectGUID must not be specified!");
 127                 return LDB_ERR_UNWILLING_TO_PERFORM;
 128         }
 129
 130         ac = talloc(req, struct og_context);
 131         if (ac == NULL) {
 132                 return ldb_oom(ldb);
 133         }
 134         ac->module = module;
 135         ac->req = req;
 136
 137         /* we have to copy the message as the caller might have it as a const */
 138         msg = ldb_msg_copy_shallow(ac, req->op.add.message);
 139         if (msg == NULL) {
 140                 talloc_free(ac);
 141                 return ldb_operr(ldb);
 142         }
 143
 144         /* a new GUID */
 145         guid = GUID_random();
 146
 147         ret = dsdb_msg_add_guid(msg, &guid, "objectGUID");
 148         if (ret != LDB_SUCCESS) {
 149                 return ret;
 150         }
 151
 152         if (add_time_element(msg, "whenCreated", t) != LDB_SUCCESS ||
 153             add_time_element(msg, "whenChanged", t) != LDB_SUCCESS) {
 154                 return ldb_operr(ldb);
 155         }
 156
 157         /* Get a sequence number from the backend */
 158         ret = ldb_sequence_number(ldb, LDB_SEQ_NEXT, &seq_num);
 159         if (ret == LDB_SUCCESS) {
 160                 if (add_uint64_element(ldb, msg, "uSNCreated",
 161                                        seq_num) != LDB_SUCCESS ||
 162                     add_uint64_element(ldb, msg, "uSNChanged",
 163                                        seq_num) != LDB_SUCCESS) {
 164                         return ldb_operr(ldb);
 165                 }
 166         }
 167
 168         ret = ldb_build_add_req(&down_req, ldb, ac,
 169                                 msg,
 170                                 req->controls,
 171                                 req, dsdb_next_callback,
 172                                 req);
 173         LDB_REQ_SET_LOCATION(down_req);
 174         if (ret != LDB_SUCCESS) {
 175                 return ret;
 176         }
 177
 178         /* go on with the call chain */
 179         return ldb_next_request(module, down_req);
 180 }
 181
 182 /* modify_record: update timestamps */
 183 static int objectguid_modify(struct ldb_module *module, struct ldb_request *req)
 184 {
 185         struct ldb_context *ldb;
 186         struct ldb_request *down_req;
 187         struct ldb_message *msg;
 188         struct ldb_message_element *el;
 189         int ret;
 190         time_t t = time(NULL);
 191         uint64_t seq_num;
 192         struct og_context *ac;
 193
 194         ldb = ldb_module_get_ctx(module);
 195
 196         ldb_debug(ldb, LDB_DEBUG_TRACE, "objectguid_modify_record\n");
 197
 198         /* do not manipulate our control entries */
 199         if (ldb_dn_is_special(req->op.add.message->dn)) {
 200                 return ldb_next_request(module, req);
 201         }
 202
 203         el = ldb_msg_find_element(req->op.mod.message, "objectGUID");
 204         if (el != NULL) {
 205                 ldb_set_errstring(ldb,
 206                                   "objectguid: objectGUID must not be specified!");
 207                 return LDB_ERR_CONSTRAINT_VIOLATION;
 208         }
 209
 210         ac = talloc(req, struct og_context);
 211         if (ac == NULL) {
 212                 return ldb_oom(ldb);
 213         }
 214         ac->module = module;
 215         ac->req = req;
 216
 217         /* we have to copy the message as the caller might have it as a const */
 218         msg = ldb_msg_copy_shallow(ac, req->op.mod.message);
 219         if (msg == NULL) {
 220                 return ldb_operr(ldb);
 221         }
 222
 223         if (add_time_element(msg, "whenChanged", t) != LDB_SUCCESS) {
 224                 return ldb_operr(ldb);
 225         }
 226
 227         /* Get a sequence number from the backend */
 228         ret = ldb_sequence_number(ldb, LDB_SEQ_NEXT, &seq_num);
 229         if (ret == LDB_SUCCESS) {
 230                 if (add_uint64_element(ldb, msg, "uSNChanged",
 231                                        seq_num) != LDB_SUCCESS) {
 232                         return ldb_operr(ldb);
 233                 }
 234         }
 235
 236         ret = ldb_build_mod_req(&down_req, ldb, ac,
 237                                 msg,
 238                                 req->controls,
 239                                 req, dsdb_next_callback,
 240                                 req);
 241         LDB_REQ_SET_LOCATION(down_req);
 242         if (ret != LDB_SUCCESS) {
 243                 return ret;
 244         }
 245
 246         /* go on with the call chain */
 247         return ldb_next_request(module, down_req);
 248 }
 249
 250 static const struct ldb_module_ops ldb_objectguid_module_ops = {
 251         .name          = "objectguid",
 252         .add           = objectguid_add,
 253         .modify        = objectguid_modify
 254 };
 255
 256 int ldb_objectguid_module_init(const char *version)
 257 {
 258         LDB_MODULE_CHECK_VERSION(version);
 259         return ldb_register_module(&ldb_objectguid_module_ops);
 260 }