source4/dsdb/repl/drepl_ridalloc.c

   1 /*
   2    Unix SMB/CIFS mplementation.
   3
   4    DSDB replication service - RID allocation code
   5
   6    Copyright (C) Andrew Tridgell 2010
   7    Copyright (C) Andrew Bartlett 2010
   8
   9    based on drepl_notify.c
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 3 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 */
  25
  26 #include "includes.h"
  27 #include "ldb_module.h"
  28 #include "dsdb/samdb/samdb.h"
  29 #include "smbd/service.h"
  30 #include "dsdb/repl/drepl_service.h"
  31 #include "param/param.h"
  32
  33 /*
  34   called when a rid allocation request has completed
  35  */
  36 static void drepl_new_rid_pool_callback(struct dreplsrv_service *service,
  37                                         WERROR werr,
  38                                         enum drsuapi_DsExtendedError ext_err,
  39                                         void *cb_data)
  40 {
  41         if (!W_ERROR_IS_OK(werr)) {
  42                 DEBUG(0,(__location__ ": RID Manager failed RID allocation - %s - extended_ret[0x%X]\n",
  43                          win_errstr(werr), ext_err));
  44         } else {
  45                 DEBUG(3,(__location__ ": RID Manager completed RID allocation OK\n"));
  46         }
  47
  48         service->rid_alloc_in_progress = false;
  49 }
  50
  51 /*
  52   schedule a getncchanges request to the RID Manager to ask for a new
  53   set of RIDs using DRSUAPI_EXOP_FSMO_RID_ALLOC
  54  */
  55 static WERROR drepl_request_new_rid_pool(struct dreplsrv_service *service,
  56                                          struct ldb_dn *rid_manager_dn, struct ldb_dn *fsmo_role_dn,
  57                                          uint64_t alloc_pool)
  58 {
  59         WERROR werr = drepl_request_extended_op(service,
  60                                                 rid_manager_dn,
  61                                                 fsmo_role_dn,
  62                                                 DRSUAPI_EXOP_FSMO_RID_ALLOC,
  63                                                 alloc_pool,
  64                                                 0,
  65                                                 drepl_new_rid_pool_callback, NULL);
  66         if (W_ERROR_IS_OK(werr)) {
  67                 service->rid_alloc_in_progress = true;
  68         }
  69         return werr;
  70 }
  71
  72
  73 /*
  74   see if we are on the last pool we have
  75  */
  76 static int drepl_ridalloc_pool_exhausted(struct ldb_context *ldb,
  77                                          bool *exhausted,
  78                                          uint64_t *_alloc_pool)
  79 {
  80         struct ldb_dn *server_dn, *machine_dn, *rid_set_dn;
  81         TALLOC_CTX *tmp_ctx = talloc_new(ldb);
  82         uint64_t alloc_pool;
  83         uint64_t prev_pool;
  84         uint32_t prev_pool_lo, prev_pool_hi;
  85         uint32_t next_rid;
  86         static const char * const attrs[] = {
  87                 "rIDAllocationPool",
  88                 "rIDPreviousAllocationPool",
  89                 "rIDNextRid",
  90                 NULL
  91         };
  92         int ret;
  93         struct ldb_result *res;
  94
  95         *exhausted = false;
  96         *_alloc_pool = UINT64_MAX;
  97
  98         server_dn = ldb_dn_get_parent(tmp_ctx, samdb_ntds_settings_dn(ldb));
  99         if (!server_dn) {
 100                 talloc_free(tmp_ctx);
 101                 return ldb_operr(ldb);
 102         }
 103
 104         ret = samdb_reference_dn(ldb, tmp_ctx, server_dn, "serverReference", &machine_dn);
 105         if (ret != LDB_SUCCESS) {
 106                 DEBUG(0,(__location__ ": Failed to find serverReference in %s - %s\n",
 107                          ldb_dn_get_linearized(server_dn), ldb_errstring(ldb)));
 108                 talloc_free(tmp_ctx);
 109                 return ret;
 110         }
 111
 112         ret = samdb_reference_dn(ldb, tmp_ctx, machine_dn, "rIDSetReferences", &rid_set_dn);
 113         if (ret == LDB_ERR_NO_SUCH_ATTRIBUTE) {
 114                 *exhausted = true;
 115                 *_alloc_pool = 0;
 116                 talloc_free(tmp_ctx);
 117                 return LDB_SUCCESS;
 118         }
 119         if (ret != LDB_SUCCESS) {
 120                 DEBUG(0,(__location__ ": Failed to find rIDSetReferences in %s - %s\n",
 121                          ldb_dn_get_linearized(machine_dn), ldb_errstring(ldb)));
 122                 talloc_free(tmp_ctx);
 123                 return ret;
 124         }
 125
 126         ret = ldb_search(ldb, tmp_ctx, &res, rid_set_dn, LDB_SCOPE_BASE, attrs, NULL);
 127         if (ret != LDB_SUCCESS) {
 128                 DEBUG(0,(__location__ ": Failed to load RID Set attrs from %s - %s\n",
 129                          ldb_dn_get_linearized(rid_set_dn), ldb_errstring(ldb)));
 130                 talloc_free(tmp_ctx);
 131                 return ret;
 132         }
 133
 134         alloc_pool = ldb_msg_find_attr_as_uint64(res->msgs[0], "rIDAllocationPool", 0);
 135         prev_pool = ldb_msg_find_attr_as_uint64(res->msgs[0], "rIDPreviousAllocationPool", 0);
 136         prev_pool_lo = prev_pool & 0xFFFFFFFF;
 137         prev_pool_hi = prev_pool >> 32;
 138         next_rid = ldb_msg_find_attr_as_uint(res->msgs[0], "rIDNextRid", 0);
 139
 140         if (alloc_pool != prev_pool) {
 141                 talloc_free(tmp_ctx);
 142                 return LDB_SUCCESS;
 143         }
 144
 145         if (next_rid < (prev_pool_hi + prev_pool_lo)/2) {
 146                 talloc_free(tmp_ctx);
 147                 return LDB_SUCCESS;
 148         }
 149
 150         *exhausted = true;
 151         *_alloc_pool = alloc_pool;
 152         talloc_free(tmp_ctx);
 153         return LDB_SUCCESS;
 154 }
 155
 156
 157 /*
 158   see if we are low on RIDs in the RID Set rIDAllocationPool. If we
 159   are, then schedule a replication call with DRSUAPI_EXOP_FSMO_RID_ALLOC
 160   to the RID Manager
 161  */
 162 WERROR dreplsrv_ridalloc_check_rid_pool(struct dreplsrv_service *service)
 163 {
 164         struct ldb_dn *rid_manager_dn, *fsmo_role_dn;
 165         TALLOC_CTX *tmp_ctx = talloc_new(service);
 166         struct ldb_context *ldb = service->samdb;
 167         bool exhausted;
 168         WERROR werr;
 169         int ret;
 170         uint64_t alloc_pool;
 171
 172         if (service->am_rodc) {
 173                 talloc_free(tmp_ctx);
 174                 return WERR_OK;
 175         }
 176
 177         if (service->rid_alloc_in_progress) {
 178                 talloc_free(tmp_ctx);
 179                 return WERR_OK;
 180         }
 181
 182         /*
 183           steps:
 184             - find who the RID Manager is
 185             - if we are the RID Manager then nothing to do
 186             - find our RID Set object
 187             - load rIDAllocationPool and rIDPreviousAllocationPool
 188             - if rIDAllocationPool != rIDPreviousAllocationPool then
 189               nothing to do
 190             - schedule a getncchanges with DRSUAPI_EXOP_FSMO_RID_ALLOC
 191               to the RID Manager
 192          */
 193
 194         /* work out who is the RID Manager */
 195         ret = samdb_rid_manager_dn(ldb, tmp_ctx, &rid_manager_dn);
 196         if (ret != LDB_SUCCESS) {
 197                 DEBUG(0, (__location__ ": Failed to find RID Manager object - %s\n", ldb_errstring(ldb)));
 198                 talloc_free(tmp_ctx);
 199                 return WERR_DS_DRA_INTERNAL_ERROR;
 200         }
 201
 202         /* find the DN of the RID Manager */
 203         ret = samdb_reference_dn(ldb, tmp_ctx, rid_manager_dn, "fSMORoleOwner", &fsmo_role_dn);
 204         if (ret != LDB_SUCCESS) {
 205                 DEBUG(0,(__location__ ": Failed to find fSMORoleOwner in RID Manager object - %s\n",
 206                          ldb_errstring(ldb)));
 207                 talloc_free(tmp_ctx);
 208                 return WERR_DS_DRA_INTERNAL_ERROR;
 209         }
 210
 211         if (ldb_dn_compare(samdb_ntds_settings_dn(ldb), fsmo_role_dn) == 0) {
 212                 /* we are the RID Manager - no need to do a
 213                    DRSUAPI_EXOP_FSMO_RID_ALLOC */
 214                 talloc_free(tmp_ctx);
 215                 return WERR_OK;
 216         }
 217
 218         ret = drepl_ridalloc_pool_exhausted(ldb, &exhausted, &alloc_pool);
 219         if (ret != LDB_SUCCESS) {
 220                 talloc_free(tmp_ctx);
 221                 return WERR_DS_DRA_INTERNAL_ERROR;
 222         }
 223
 224         if (!exhausted) {
 225                 /* don't need a new pool */
 226                 talloc_free(tmp_ctx);
 227                 return WERR_OK;
 228         }
 229
 230         DEBUG(2,(__location__ ": Requesting more RIDs from RID Manager\n"));
 231
 232         werr = drepl_request_new_rid_pool(service, rid_manager_dn, fsmo_role_dn, alloc_pool);
 233         talloc_free(tmp_ctx);
 234         return werr;
 235 }
 236
 237 /* called by the samldb ldb module to tell us to ask for a new RID
 238    pool */
 239 void dreplsrv_allocate_rid(struct imessaging_context *msg, void *private_data,
 240                            uint32_t msg_type,
 241                            struct server_id server_id, DATA_BLOB *data)
 242 {
 243         struct dreplsrv_service *service = talloc_get_type(private_data, struct dreplsrv_service);
 244         dreplsrv_ridalloc_check_rid_pool(service);
 245 }