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 /*
  35   create the RID manager source dsa structure
  36  */
  37
  38 WERROR drepl_create_role_owner_source_dsa(struct dreplsrv_service *service,
  39                                           struct ldb_dn *role_owner_dn, struct ldb_dn *fsmo_role_dn)
  40 {
  41         struct dreplsrv_partition_source_dsa *sdsa;
  42         struct ldb_context *ldb = service->samdb;
  43         int ret;
  44         WERROR werr;
  45
  46         sdsa = talloc_zero(service, struct dreplsrv_partition_source_dsa);
  47         W_ERROR_HAVE_NO_MEMORY(sdsa);
  48
  49         sdsa->partition = talloc_zero(sdsa, struct dreplsrv_partition);
  50         if (!sdsa->partition) {
  51                 talloc_free(sdsa);
  52                 return WERR_NOMEM;
  53         }
  54
  55         sdsa->partition->dn = ldb_get_default_basedn(ldb);
  56         sdsa->partition->nc.dn = ldb_dn_alloc_linearized(sdsa->partition, role_owner_dn);
  57         ret = dsdb_find_guid_by_dn(ldb, role_owner_dn, &sdsa->partition->nc.guid);
  58         if (ret != LDB_SUCCESS) {
  59                 DEBUG(0,(__location__ ": Failed to find GUID for %s\n",
  60                          ldb_dn_get_linearized(role_owner_dn)));
  61                 talloc_free(sdsa);
  62                 return WERR_DS_DRA_INTERNAL_ERROR;
  63         }
  64
  65         sdsa->repsFrom1 = &sdsa->_repsFromBlob.ctr.ctr1;
  66         ret = dsdb_find_guid_attr_by_dn(ldb, fsmo_role_dn, "objectGUID", &sdsa->repsFrom1->source_dsa_obj_guid);
  67         if (ret != LDB_SUCCESS) {
  68                 DEBUG(0,(__location__ ": Failed to find objectGUID for %s\n",
  69                          ldb_dn_get_linearized(fsmo_role_dn)));
  70                 talloc_free(sdsa);
  71                 return WERR_DS_DRA_INTERNAL_ERROR;
  72         }
  73
  74         sdsa->repsFrom1->other_info = talloc_zero(sdsa, struct repsFromTo1OtherInfo);
  75         if (!sdsa->repsFrom1->other_info) {
  76                 talloc_free(sdsa);
  77                 return WERR_NOMEM;
  78         }
  79
  80         sdsa->repsFrom1->other_info->dns_name =
  81                 talloc_asprintf(sdsa->repsFrom1->other_info, "%s._msdcs.%s",
  82                                 GUID_string(sdsa->repsFrom1->other_info, &sdsa->repsFrom1->source_dsa_obj_guid),
  83                                 lpcfg_dnsdomain(service->task->lp_ctx));
  84         if (!sdsa->repsFrom1->other_info->dns_name) {
  85                 talloc_free(sdsa);
  86                 return WERR_NOMEM;
  87         }
  88
  89
  90         werr = dreplsrv_out_connection_attach(service, sdsa->repsFrom1, &sdsa->conn);
  91         if (!W_ERROR_IS_OK(werr)) {
  92                 DEBUG(0,(__location__ ": Failed to attach connection to %s\n",
  93                          ldb_dn_get_linearized(role_owner_dn)));
  94                 talloc_free(sdsa);
  95                 return werr;
  96         }
  97
  98         service->ncchanges_extended.role_owner_source_dsa = sdsa;
  99         return WERR_OK;
 100 }
 101
 102 /*
 103   schedule a getncchanges request to the role owner for an extended operation
 104  */
 105 WERROR drepl_request_extended_op(struct dreplsrv_service *service,
 106                                  struct ldb_dn *role_owner_dn,
 107                                  struct ldb_dn *fsmo_role_dn,
 108                                  enum drsuapi_DsExtendedOperation extended_op,
 109                                  uint64_t alloc_pool,
 110                                  dreplsrv_fsmo_callback_t callback)
 111 {
 112         WERROR werr;
 113
 114         if (service->ncchanges_extended.role_owner_source_dsa == NULL) {
 115                 /* we need to establish a connection to the RID
 116                    Manager */
 117                 werr = drepl_create_role_owner_source_dsa(service, role_owner_dn, fsmo_role_dn);
 118                 W_ERROR_NOT_OK_RETURN(werr);
 119         }
 120
 121         service->ncchanges_extended.in_progress = true;
 122
 123         werr = dreplsrv_schedule_partition_pull_source(service, service->ncchanges_extended.role_owner_source_dsa,
 124                                                        extended_op, alloc_pool,
 125                                                        callback);
 126         return werr;
 127 }
 128
 129 /*
 130   called when a rid allocation request has completed
 131  */
 132 static void drepl_new_rid_pool_callback(struct dreplsrv_service *service,
 133                                         WERROR werr,
 134                                         enum drsuapi_DsExtendedError ext_err)
 135 {
 136         if (!W_ERROR_IS_OK(werr)) {
 137                 DEBUG(0,(__location__ ": RID Manager failed RID allocation - %s - extended_ret[0x%X]\n",
 138                          win_errstr(werr), ext_err));
 139         } else {
 140                 DEBUG(3,(__location__ ": RID Manager completed RID allocation OK\n"));
 141         }
 142
 143         /* don't keep the connection open to the RID Manager */
 144         talloc_free(service->ncchanges_extended.role_owner_source_dsa);
 145         service->ncchanges_extended.role_owner_source_dsa = NULL;
 146
 147         service->ncchanges_extended.in_progress = false;
 148 }
 149
 150 /*
 151   schedule a getncchanges request to the RID Manager to ask for a new
 152   set of RIDs using DRSUAPI_EXOP_FSMO_RID_ALLOC
 153  */
 154 static WERROR drepl_request_new_rid_pool(struct dreplsrv_service *service,
 155                                          struct ldb_dn *rid_manager_dn, struct ldb_dn *fsmo_role_dn,
 156                                          uint64_t alloc_pool)
 157 {
 158         WERROR werr = drepl_request_extended_op(service,
 159                                                 rid_manager_dn,
 160                                                 fsmo_role_dn,
 161                                                 DRSUAPI_EXOP_FSMO_RID_ALLOC,
 162                                                 alloc_pool,
 163                                                 drepl_new_rid_pool_callback);
 164         return werr;
 165 }
 166
 167
 168 /*
 169   see if we are on the last pool we have
 170  */
 171 static int drepl_ridalloc_pool_exhausted(struct ldb_context *ldb,
 172                                          bool *exhausted,
 173                                          uint64_t *_alloc_pool)
 174 {
 175         struct ldb_dn *server_dn, *machine_dn, *rid_set_dn;
 176         TALLOC_CTX *tmp_ctx = talloc_new(ldb);
 177         uint64_t alloc_pool;
 178         uint64_t prev_pool;
 179         uint32_t prev_pool_lo, prev_pool_hi;
 180         uint32_t next_rid;
 181         static const char * const attrs[] = {
 182                 "rIDAllocationPool",
 183                 "rIDPreviousAllocationPool",
 184                 "rIDNextRid",
 185                 NULL
 186         };
 187         int ret;
 188         struct ldb_result *res;
 189
 190         *exhausted = false;
 191         *_alloc_pool = UINT64_MAX;
 192
 193         server_dn = ldb_dn_get_parent(tmp_ctx, samdb_ntds_settings_dn(ldb));
 194         if (!server_dn) {
 195                 talloc_free(tmp_ctx);
 196                 return ldb_operr(ldb);
 197         }
 198
 199         ret = samdb_reference_dn(ldb, tmp_ctx, server_dn, "serverReference", &machine_dn);
 200         if (ret != LDB_SUCCESS) {
 201                 DEBUG(0,(__location__ ": Failed to find serverReference in %s - %s",
 202                          ldb_dn_get_linearized(server_dn), ldb_errstring(ldb)));
 203                 talloc_free(tmp_ctx);
 204                 return ret;
 205         }
 206
 207         ret = samdb_reference_dn(ldb, tmp_ctx, machine_dn, "rIDSetReferences", &rid_set_dn);
 208         if (ret == LDB_ERR_NO_SUCH_ATTRIBUTE) {
 209                 *exhausted = true;
 210                 *_alloc_pool = 0;
 211                 talloc_free(tmp_ctx);
 212                 return LDB_SUCCESS;
 213         }
 214         if (ret != LDB_SUCCESS) {
 215                 DEBUG(0,(__location__ ": Failed to find rIDSetReferences in %s - %s",
 216                          ldb_dn_get_linearized(machine_dn), ldb_errstring(ldb)));
 217                 talloc_free(tmp_ctx);
 218                 return ret;
 219         }
 220
 221         ret = ldb_search(ldb, tmp_ctx, &res, rid_set_dn, LDB_SCOPE_BASE, attrs, NULL);
 222         if (ret != LDB_SUCCESS) {
 223                 DEBUG(0,(__location__ ": Failed to load RID Set attrs from %s - %s",
 224                          ldb_dn_get_linearized(rid_set_dn), ldb_errstring(ldb)));
 225                 talloc_free(tmp_ctx);
 226                 return ret;
 227         }
 228
 229         alloc_pool = ldb_msg_find_attr_as_uint64(res->msgs[0], "rIDAllocationPool", 0);
 230         prev_pool = ldb_msg_find_attr_as_uint64(res->msgs[0], "rIDPreviousAllocationPool", 0);
 231         prev_pool_lo = prev_pool & 0xFFFFFFFF;
 232         prev_pool_hi = prev_pool >> 32;
 233         next_rid = ldb_msg_find_attr_as_uint(res->msgs[0], "rIDNextRid", 0);
 234
 235         if (alloc_pool != prev_pool) {
 236                 talloc_free(tmp_ctx);
 237                 return LDB_SUCCESS;
 238         }
 239
 240         if (next_rid < (prev_pool_hi + prev_pool_lo)/2) {
 241                 talloc_free(tmp_ctx);
 242                 return LDB_SUCCESS;
 243         }
 244
 245         *exhausted = true;
 246         *_alloc_pool = alloc_pool;
 247         talloc_free(tmp_ctx);
 248         return LDB_SUCCESS;
 249 }
 250
 251
 252 /*
 253   see if we are low on RIDs in the RID Set rIDAllocationPool. If we
 254   are, then schedule a replication call with DRSUAPI_EXOP_FSMO_RID_ALLOC
 255   to the RID Manager
 256  */
 257 WERROR dreplsrv_ridalloc_check_rid_pool(struct dreplsrv_service *service)
 258 {
 259         struct ldb_dn *rid_manager_dn, *fsmo_role_dn;
 260         TALLOC_CTX *tmp_ctx = talloc_new(service);
 261         struct ldb_context *ldb = service->samdb;
 262         bool exhausted;
 263         WERROR werr;
 264         int ret;
 265         uint64_t alloc_pool;
 266
 267         if (service->ncchanges_extended.in_progress) {
 268                 talloc_free(tmp_ctx);
 269                 return WERR_OK;
 270         }
 271
 272         /*
 273           steps:
 274             - find who the RID Manager is
 275             - if we are the RID Manager then nothing to do
 276             - find our RID Set object
 277             - load rIDAllocationPool and rIDPreviousAllocationPool
 278             - if rIDAllocationPool != rIDPreviousAllocationPool then
 279               nothing to do
 280             - schedule a getncchanges with DRSUAPI_EXOP_FSMO_RID_ALLOC
 281               to the RID Manager
 282          */
 283
 284         /* work out who is the RID Manager */
 285         ret = samdb_rid_manager_dn(ldb, tmp_ctx, &rid_manager_dn);
 286         if (ret != LDB_SUCCESS) {
 287                 DEBUG(0, (__location__ ": Failed to find RID Manager object - %s", ldb_errstring(ldb)));
 288                 talloc_free(tmp_ctx);
 289                 return WERR_DS_DRA_INTERNAL_ERROR;
 290         }
 291
 292         /* find the DN of the RID Manager */
 293         ret = samdb_reference_dn(ldb, tmp_ctx, rid_manager_dn, "fSMORoleOwner", &fsmo_role_dn);
 294         if (ret != LDB_SUCCESS) {
 295                 DEBUG(0,(__location__ ": Failed to find fSMORoleOwner in RID Manager object - %s",
 296                          ldb_errstring(ldb)));
 297                 talloc_free(tmp_ctx);
 298                 return WERR_DS_DRA_INTERNAL_ERROR;
 299         }
 300
 301         if (ldb_dn_compare(samdb_ntds_settings_dn(ldb), fsmo_role_dn) == 0) {
 302                 /* we are the RID Manager - no need to do a
 303                    DRSUAPI_EXOP_FSMO_RID_ALLOC */
 304                 talloc_free(tmp_ctx);
 305                 return WERR_OK;
 306         }
 307
 308         ret = drepl_ridalloc_pool_exhausted(ldb, &exhausted, &alloc_pool);
 309         if (ret != LDB_SUCCESS) {
 310                 talloc_free(tmp_ctx);
 311                 return WERR_DS_DRA_INTERNAL_ERROR;
 312         }
 313
 314         if (!exhausted) {
 315                 /* don't need a new pool */
 316                 talloc_free(tmp_ctx);
 317                 return WERR_OK;
 318         }
 319
 320         DEBUG(2,(__location__ ": Requesting more RIDs from RID Manager\n"));
 321
 322         werr = drepl_request_new_rid_pool(service, rid_manager_dn, fsmo_role_dn, alloc_pool);
 323         talloc_free(tmp_ctx);
 324         return werr;
 325 }
 326
 327 /* called by the samldb ldb module to tell us to ask for a new RID
 328    pool */
 329 void dreplsrv_allocate_rid(struct messaging_context *msg, void *private_data,
 330                            uint32_t msg_type,
 331                            struct server_id server_id, DATA_BLOB *data)
 332 {
 333         struct dreplsrv_service *service = talloc_get_type(private_data, struct dreplsrv_service);
 334         dreplsrv_ridalloc_check_rid_pool(service);
 335 }