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/*
Unix SMB/CIFS mplementation.
The module that handles the Schema FSMO Role Owner
checkings, it also loads the dsdb_schema.
Copyright (C) Stefan Metzmacher <metze@samba.org> 2007
Copyright (C) Andrew Bartlett <abartlet@samba.org> 2009-2010
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "ldb_module.h"
#include "dsdb/samdb/samdb.h"
#include "librpc/gen_ndr/ndr_misc.h"
#include "librpc/gen_ndr/ndr_drsuapi.h"
#include "librpc/gen_ndr/ndr_drsblobs.h"
#include "param/param.h"
#include "dsdb/samdb/ldb_modules/util.h"
struct schema_load_private_data {
bool in_transaction;
};
static int dsdb_schema_from_db(struct ldb_module *module, struct ldb_dn *schema_dn, uint64_t current_usn,
struct dsdb_schema **schema);
static struct dsdb_schema *dsdb_schema_refresh(struct ldb_module *module, struct dsdb_schema *schema, bool is_global_schema)
{
uint64_t current_usn;
int ret;
struct ldb_result *res;
struct ldb_request *treq;
struct ldb_seqnum_request *tseq;
struct ldb_seqnum_result *tseqr;
struct dsdb_control_current_partition *ctrl;
struct ldb_context *ldb = ldb_module_get_ctx(module);
struct dsdb_schema *new_schema;
int interval;
time_t ts, lastts;
struct loadparm_context *lp_ctx =
(struct loadparm_context *)ldb_get_opaque(ldb, "loadparm");
struct schema_load_private_data *private_data = talloc_get_type(ldb_module_get_private(module), struct schema_load_private_data);
if (!private_data) {
/* We can't refresh until the init function has run */
return schema;
}
/* We don't allow a schema reload during a transaction - nobody else can modify our schema behind our backs */
if (private_data->in_transaction) {
return schema;
}
lastts = schema->last_refresh;
ts = time(NULL);
interval = lpcfg_parm_int(lp_ctx, NULL, "dsdb", "schema_reload_interval", 120);
if (lastts > (ts - interval)) {
DEBUG(11, ("Less than %d seconds since last reload, returning cached version ts = %d\n", interval, (int)lastts));
return schema;
}
res = talloc_zero(schema, struct ldb_result);
if (res == NULL) {
return NULL;
}
tseq = talloc_zero(res, struct ldb_seqnum_request);
if (tseq == NULL) {
talloc_free(res);
return NULL;
}
tseq->type = LDB_SEQ_HIGHEST_SEQ;
ret = ldb_build_extended_req(&treq, ldb_module_get_ctx(module), res,
LDB_EXTENDED_SEQUENCE_NUMBER,
tseq,
NULL,
res,
ldb_extended_default_callback,
NULL);
LDB_REQ_SET_LOCATION(treq);
if (ret != LDB_SUCCESS) {
talloc_free(res);
return NULL;
}
/*
* We update right now the last refresh timestamp so that if
* the schema partition hasn't change we don't keep on retrying.
* Otherwise if the timestamp was update only when the schema has
* actually changed (and therefor completely reloaded) we would
* continue to hit the database to get the highest USN.
*/
schema->last_refresh = ts;
ctrl = talloc(treq, struct dsdb_control_current_partition);
if (!ctrl) {
talloc_free(res);
return NULL;
}
ctrl->version = DSDB_CONTROL_CURRENT_PARTITION_VERSION;
ctrl->dn = schema->base_dn;
ret = ldb_request_add_control(treq,
DSDB_CONTROL_CURRENT_PARTITION_OID,
false, ctrl);
if (ret != LDB_SUCCESS) {
talloc_free(res);
return NULL;
}
ret = ldb_next_request(module, treq);
if (ret != LDB_SUCCESS) {
talloc_free(res);
return NULL;
}
ret = ldb_wait(treq->handle, LDB_WAIT_ALL);
if (ret != LDB_SUCCESS) {
talloc_free(res);
return NULL;
}
tseqr = talloc_get_type(res->extended->data,
struct ldb_seqnum_result);
if (tseqr->seq_num == schema->reload_seq_number) {
talloc_free(res);
return schema;
}
schema->reload_seq_number = tseqr->seq_num;
talloc_free(res);
ret = dsdb_module_load_partition_usn(module, schema->base_dn, ¤t_usn, NULL, NULL);
if (ret != LDB_SUCCESS || current_usn == schema->loaded_usn) {
return schema;
}
ret = dsdb_schema_from_db(module, schema->base_dn, current_usn, &new_schema);
if (ret != LDB_SUCCESS) {
return schema;
}
if (is_global_schema) {
dsdb_make_schema_global(ldb, new_schema);
}
return new_schema;
}
/*
Given an LDB module (pointing at the schema DB), and the DN, set the populated schema
*/
static int dsdb_schema_from_db(struct ldb_module *module, struct ldb_dn *schema_dn, uint64_t current_usn,
struct dsdb_schema **schema)
{
struct ldb_context *ldb = ldb_module_get_ctx(module);
TALLOC_CTX *tmp_ctx;
char *error_string;
int ret;
struct ldb_result *schema_res;
struct ldb_result *res;
static const char *schema_attrs[] = {
"prefixMap",
"schemaInfo",
"fSMORoleOwner",
NULL
};
unsigned flags;
tmp_ctx = talloc_new(module);
if (!tmp_ctx) {
return ldb_oom(ldb);
}
/* we don't want to trace the schema load */
flags = ldb_get_flags(ldb);
ldb_set_flags(ldb, flags & ~LDB_FLG_ENABLE_TRACING);
/*
* setup the prefix mappings and schema info
*/
ret = dsdb_module_search_dn(module, tmp_ctx, &schema_res,
schema_dn, schema_attrs,
DSDB_FLAG_NEXT_MODULE, NULL);
if (ret == LDB_ERR_NO_SUCH_OBJECT) {
ldb_reset_err_string(ldb);
ldb_debug(ldb, LDB_DEBUG_WARNING,
"schema_load_init: no schema head present: (skip schema loading)\n");
goto failed;
} else if (ret != LDB_SUCCESS) {
ldb_asprintf_errstring(ldb,
"dsdb_schema: failed to search the schema head: %s",
ldb_errstring(ldb));
goto failed;
}
/*
* load the attribute definitions
*/
ret = dsdb_module_search(module, tmp_ctx, &res,
schema_dn, LDB_SCOPE_ONELEVEL, NULL,
DSDB_FLAG_NEXT_MODULE |
DSDB_SEARCH_SHOW_DN_IN_STORAGE_FORMAT,
NULL,
"(|(objectClass=attributeSchema)(objectClass=classSchema))");
if (ret != LDB_SUCCESS) {
ldb_asprintf_errstring(ldb,
"dsdb_schema: failed to search attributeSchema and classSchema objects: %s",
ldb_errstring(ldb));
goto failed;
}
ret = dsdb_schema_from_ldb_results(tmp_ctx, ldb,
schema_res, res, schema, &error_string);
if (ret != LDB_SUCCESS) {
ldb_asprintf_errstring(ldb,
"dsdb_schema load failed: %s",
error_string);
goto failed;
}
(*schema)->refresh_in_progress = true;
/* If we have the readOnlySchema opaque, then don't check for
* runtime schema updates, as they are not permitted (we would
* have to update the backend server schema too */
if (!ldb_get_opaque(ldb, "readOnlySchema")) {
(*schema)->refresh_fn = dsdb_schema_refresh;
(*schema)->loaded_from_module = module;
(*schema)->loaded_usn = current_usn;
}
/* "dsdb_set_schema()" steals schema into the ldb_context */
ret = dsdb_set_schema(ldb, (*schema));
(*schema)->refresh_in_progress = false;
(*schema)->last_refresh = time(NULL);
if (ret != LDB_SUCCESS) {
ldb_debug_set(ldb, LDB_DEBUG_FATAL,
"schema_load_init: dsdb_set_schema() failed: %d:%s: %s",
ret, ldb_strerror(ret), ldb_errstring(ldb));
goto failed;
}
/* Ensure this module won't go away before the callback */
if (talloc_reference(*schema, ldb) == NULL) {
ldb_oom(ldb);
ret = LDB_ERR_OPERATIONS_ERROR;
}
failed:
if (flags & LDB_FLG_ENABLE_TRACING) {
flags = ldb_get_flags(ldb);
ldb_set_flags(ldb, flags | LDB_FLG_ENABLE_TRACING);
}
talloc_free(tmp_ctx);
return ret;
}
static int schema_load_init(struct ldb_module *module)
{
struct schema_load_private_data *private_data;
struct dsdb_schema *schema;
struct ldb_context *ldb = ldb_module_get_ctx(module);
int ret;
uint64_t current_usn;
struct ldb_dn *schema_dn;
private_data = talloc_zero(module, struct schema_load_private_data);
if (private_data == NULL) {
return ldb_oom(ldb);
}
ldb_module_set_private(module, private_data);
ret = ldb_next_init(module);
if (ret != LDB_SUCCESS) {
return ret;
}
if (dsdb_get_schema(ldb, NULL)) {
return LDB_SUCCESS;
}
schema_dn = ldb_get_schema_basedn(ldb);
if (!schema_dn) {
ldb_reset_err_string(ldb);
ldb_debug(ldb, LDB_DEBUG_WARNING,
"schema_load_init: no schema dn present: (skip schema loading)\n");
return LDB_SUCCESS;
}
ret = dsdb_module_load_partition_usn(module, schema_dn, ¤t_usn, NULL, NULL);
if (ret != LDB_SUCCESS) {
/* Ignore the error and just reload the DB more often */
current_usn = 0;
}
return dsdb_schema_from_db(module, schema_dn, current_usn, &schema);
}
static int schema_load_start_transaction(struct ldb_module *module)
{
struct schema_load_private_data *private_data =
talloc_get_type(ldb_module_get_private(module), struct schema_load_private_data);
private_data->in_transaction = true;
return ldb_next_start_trans(module);
}
static int schema_load_end_transaction(struct ldb_module *module)
{
struct schema_load_private_data *private_data =
talloc_get_type(ldb_module_get_private(module), struct schema_load_private_data);
private_data->in_transaction = false;
return ldb_next_end_trans(module);
}
static int schema_load_del_transaction(struct ldb_module *module)
{
struct schema_load_private_data *private_data =
talloc_get_type(ldb_module_get_private(module), struct schema_load_private_data);
private_data->in_transaction = false;
return ldb_next_del_trans(module);
}
static int schema_load_extended(struct ldb_module *module, struct ldb_request *req)
{
time_t *lastts;
struct ldb_context *ldb = ldb_module_get_ctx(module);
struct dsdb_schema *schema;
if (strcmp(req->op.extended.oid, DSDB_EXTENDED_SCHEMA_UPDATE_NOW_OID) != 0) {
return ldb_next_request(module, req);
}
lastts = (time_t *)ldb_get_opaque(ldb, DSDB_OPAQUE_LAST_SCHEMA_UPDATE_MSG_OPAQUE_NAME);
if (!lastts) {
lastts = talloc(ldb, time_t);
}
schema = dsdb_get_schema(ldb, NULL);
/* Force a refresh */
schema->last_refresh = 0;
*lastts = 0;
ldb_set_opaque(ldb, DSDB_OPAQUE_LAST_SCHEMA_UPDATE_MSG_OPAQUE_NAME, lastts);
/* This is a no-op. We reload as soon as we can */
return ldb_module_done(req, NULL, NULL, LDB_SUCCESS);
}
static const struct ldb_module_ops ldb_schema_load_module_ops = {
.name = "schema_load",
.init_context = schema_load_init,
.extended = schema_load_extended,
.start_transaction = schema_load_start_transaction,
.end_transaction = schema_load_end_transaction,
.del_transaction = schema_load_del_transaction,
};
int ldb_schema_load_module_init(const char *version)
{
LDB_MODULE_CHECK_VERSION(version);
return ldb_register_module(&ldb_schema_load_module_ops);
}
|