/* 
   Unix SMB/CIFS implementation.
   Samba utility functions

   Copyright (C) Andrew Tridgell 2004
   Copyright (C) Volker Lendecke 2004
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2006
   Copyright (C) Jelmer Vernooij <jelmer@samba.org> 2007

   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 "events/events.h"
#include "ldb.h"
#include "ldb_errors.h"
#include "../lib/util/util_ldb.h"
#include "../lib/crypto/crypto.h"
#include "dsdb/samdb/samdb.h"
#include "libcli/security/security.h"
#include "librpc/gen_ndr/ndr_security.h"
#include "librpc/gen_ndr/ndr_misc.h"
#include "../libds/common/flags.h"
#include "dsdb/common/proto.h"
#include "libcli/ldap/ldap_ndr.h"
#include "param/param.h"
#include "libcli/auth/libcli_auth.h"
#include "librpc/gen_ndr/ndr_drsblobs.h"
#include "system/locale.h"

/*
  search the sam for the specified attributes in a specific domain, filter on
  objectSid being in domain_sid.
*/
int samdb_search_domain(struct ldb_context *sam_ldb,
			TALLOC_CTX *mem_ctx, 
			struct ldb_dn *basedn,
			struct ldb_message ***res,
			const char * const *attrs,
			const struct dom_sid *domain_sid,
			const char *format, ...)  _PRINTF_ATTRIBUTE(7,8)
{
	va_list ap;
	int i, count;

	va_start(ap, format);
	count = gendb_search_v(sam_ldb, mem_ctx, basedn,
			       res, attrs, format, ap);
	va_end(ap);

	i=0;

	while (i<count) {
		struct dom_sid *entry_sid;

		entry_sid = samdb_result_dom_sid(mem_ctx, (*res)[i], "objectSid");

		if ((entry_sid == NULL) ||
		    (!dom_sid_in_domain(domain_sid, entry_sid))) {
			/* Delete that entry from the result set */
			(*res)[i] = (*res)[count-1];
			count -= 1;
			talloc_free(entry_sid);
			continue;
		}
		talloc_free(entry_sid);
		i += 1;
	}

	return count;
}

/*
  search the sam for a single string attribute in exactly 1 record
*/
const char *samdb_search_string_v(struct ldb_context *sam_ldb,
				  TALLOC_CTX *mem_ctx,
				  struct ldb_dn *basedn,
				  const char *attr_name,
				  const char *format, va_list ap) _PRINTF_ATTRIBUTE(5,0)
{
	int count;
	const char *attrs[2] = { NULL, NULL };
	struct ldb_message **res = NULL;

	attrs[0] = attr_name;

	count = gendb_search_v(sam_ldb, mem_ctx, basedn, &res, attrs, format, ap);
	if (count > 1) {		
		DEBUG(1,("samdb: search for %s %s not single valued (count=%d)\n", 
			 attr_name, format, count));
	}
	if (count != 1) {
		talloc_free(res);
		return NULL;
	}

	return samdb_result_string(res[0], attr_name, NULL);
}

/*
  search the sam for a single string attribute in exactly 1 record
*/
const char *samdb_search_string(struct ldb_context *sam_ldb,
				TALLOC_CTX *mem_ctx,
				struct ldb_dn *basedn,
				const char *attr_name,
				const char *format, ...) _PRINTF_ATTRIBUTE(5,6)
{
	va_list ap;
	const char *str;

	va_start(ap, format);
	str = samdb_search_string_v(sam_ldb, mem_ctx, basedn, attr_name, format, ap);
	va_end(ap);

	return str;
}

struct ldb_dn *samdb_search_dn(struct ldb_context *sam_ldb,
			       TALLOC_CTX *mem_ctx,
			       struct ldb_dn *basedn,
			       const char *format, ...) _PRINTF_ATTRIBUTE(4,5)
{
	va_list ap;
	struct ldb_dn *ret;
	struct ldb_message **res = NULL;
	int count;

	va_start(ap, format);
	count = gendb_search_v(sam_ldb, mem_ctx, basedn, &res, NULL, format, ap);
	va_end(ap);

	if (count != 1) return NULL;

	ret = talloc_steal(mem_ctx, res[0]->dn);
	talloc_free(res);

	return ret;
}

/*
  search the sam for a dom_sid attribute in exactly 1 record
*/
struct dom_sid *samdb_search_dom_sid(struct ldb_context *sam_ldb,
				     TALLOC_CTX *mem_ctx,
				     struct ldb_dn *basedn,
				     const char *attr_name,
				     const char *format, ...) _PRINTF_ATTRIBUTE(5,6)
{
	va_list ap;
	int count;
	struct ldb_message **res;
	const char *attrs[2] = { NULL, NULL };
	struct dom_sid *sid;

	attrs[0] = attr_name;

	va_start(ap, format);
	count = gendb_search_v(sam_ldb, mem_ctx, basedn, &res, attrs, format, ap);
	va_end(ap);
	if (count > 1) {		
		DEBUG(1,("samdb: search for %s %s not single valued (count=%d)\n", 
			 attr_name, format, count));
	}
	if (count != 1) {
		talloc_free(res);
		return NULL;
	}
	sid = samdb_result_dom_sid(mem_ctx, res[0], attr_name);
	talloc_free(res);
	return sid;	
}

/*
  return the count of the number of records in the sam matching the query
*/
int samdb_search_count(struct ldb_context *sam_ldb,
		       struct ldb_dn *basedn,
		       const char *format, ...) _PRINTF_ATTRIBUTE(3,4)
{
	va_list ap;
	struct ldb_message **res;
	const char *attrs[] = { NULL };
	int ret;
	TALLOC_CTX *tmp_ctx = talloc_new(sam_ldb);

	va_start(ap, format);
	ret = gendb_search_v(sam_ldb, tmp_ctx, basedn, &res, attrs, format, ap);
	va_end(ap);
	talloc_free(tmp_ctx);

	return ret;
}


/*
  search the sam for a single integer attribute in exactly 1 record
*/
uint_t samdb_search_uint(struct ldb_context *sam_ldb,
			 TALLOC_CTX *mem_ctx,
			 uint_t default_value,
			 struct ldb_dn *basedn,
			 const char *attr_name,
			 const char *format, ...) _PRINTF_ATTRIBUTE(6,7)
{
	va_list ap;
	int count;
	struct ldb_message **res;
	const char *attrs[2] = { NULL, NULL };

	attrs[0] = attr_name;

	va_start(ap, format);
	count = gendb_search_v(sam_ldb, mem_ctx, basedn, &res, attrs, format, ap);
	va_end(ap);

	if (count != 1) {
		return default_value;
	}

	return samdb_result_uint(res[0], attr_name, default_value);
}

/*
  search the sam for a single signed 64 bit integer attribute in exactly 1 record
*/
int64_t samdb_search_int64(struct ldb_context *sam_ldb,
			   TALLOC_CTX *mem_ctx,
			   int64_t default_value,
			   struct ldb_dn *basedn,
			   const char *attr_name,
			   const char *format, ...) _PRINTF_ATTRIBUTE(6,7)
{
	va_list ap;
	int count;
	struct ldb_message **res;
	const char *attrs[2] = { NULL, NULL };

	attrs[0] = attr_name;

	va_start(ap, format);
	count = gendb_search_v(sam_ldb, mem_ctx, basedn, &res, attrs, format, ap);
	va_end(ap);

	if (count != 1) {
		return default_value;
	}

	return samdb_result_int64(res[0], attr_name, default_value);
}

/*
  search the sam for multipe records each giving a single string attribute
  return the number of matches, or -1 on error
*/
int samdb_search_string_multiple(struct ldb_context *sam_ldb,
				 TALLOC_CTX *mem_ctx,
				 struct ldb_dn *basedn,
				 const char ***strs,
				 const char *attr_name,
				 const char *format, ...) _PRINTF_ATTRIBUTE(6,7)
{
	va_list ap;
	int count, i;
	const char *attrs[2] = { NULL, NULL };
	struct ldb_message **res = NULL;

	attrs[0] = attr_name;

	va_start(ap, format);
	count = gendb_search_v(sam_ldb, mem_ctx, basedn, &res, attrs, format, ap);
	va_end(ap);

	if (count <= 0) {
		return count;
	}

	/* make sure its single valued */
	for (i=0;i<count;i++) {
		if (res[i]->num_elements != 1) {
			DEBUG(1,("samdb: search for %s %s not single valued\n", 
				 attr_name, format));
			talloc_free(res);
			return -1;
		}
	}

	*strs = talloc_array(mem_ctx, const char *, count+1);
	if (! *strs) {
		talloc_free(res);
		return -1;
	}

	for (i=0;i<count;i++) {
		(*strs)[i] = samdb_result_string(res[i], attr_name, NULL);
	}
	(*strs)[count] = NULL;

	return count;
}

/*
  pull a uint from a result set. 
*/
uint_t samdb_result_uint(const struct ldb_message *msg, const char *attr, uint_t default_value)
{
	return ldb_msg_find_attr_as_uint(msg, attr, default_value);
}

/*
  pull a (signed) int64 from a result set. 
*/
int64_t samdb_result_int64(const struct ldb_message *msg, const char *attr, int64_t default_value)
{
	return ldb_msg_find_attr_as_int64(msg, attr, default_value);
}

/*
  pull a string from a result set. 
*/
const char *samdb_result_string(const struct ldb_message *msg, const char *attr, 
				const char *default_value)
{
	return ldb_msg_find_attr_as_string(msg, attr, default_value);
}

struct ldb_dn *samdb_result_dn(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const struct ldb_message *msg,
			       const char *attr, struct ldb_dn *default_value)
{
	struct ldb_dn *ret_dn = ldb_msg_find_attr_as_dn(ldb, mem_ctx, msg, attr);
	if (!ret_dn) {
		return default_value;
	}
	return ret_dn;
}

/*
  pull a rid from a objectSid in a result set. 
*/
uint32_t samdb_result_rid_from_sid(TALLOC_CTX *mem_ctx, const struct ldb_message *msg, 
				   const char *attr, uint32_t default_value)
{
	struct dom_sid *sid;
	uint32_t rid;

	sid = samdb_result_dom_sid(mem_ctx, msg, attr);
	if (sid == NULL) {
		return default_value;
	}
	rid = sid->sub_auths[sid->num_auths-1];
	talloc_free(sid);
	return rid;
}

/*
  pull a dom_sid structure from a objectSid in a result set. 
*/
struct dom_sid *samdb_result_dom_sid(TALLOC_CTX *mem_ctx, const struct ldb_message *msg, 
				     const char *attr)
{
	const struct ldb_val *v;
	struct dom_sid *sid;
	enum ndr_err_code ndr_err;
	v = ldb_msg_find_ldb_val(msg, attr);
	if (v == NULL) {
		return NULL;
	}
	sid = talloc(mem_ctx, struct dom_sid);
	if (sid == NULL) {
		return NULL;
	}
	ndr_err = ndr_pull_struct_blob(v, sid, NULL, sid,
				       (ndr_pull_flags_fn_t)ndr_pull_dom_sid);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		talloc_free(sid);
		return NULL;
	}
	return sid;
}

/*
  pull a guid structure from a objectGUID in a result set. 
*/
struct GUID samdb_result_guid(const struct ldb_message *msg, const char *attr)
{
	const struct ldb_val *v;
	struct GUID guid;
	NTSTATUS status;

	v = ldb_msg_find_ldb_val(msg, attr);
	if (!v) return GUID_zero();

	status = GUID_from_ndr_blob(v, &guid);
	if (!NT_STATUS_IS_OK(status)) {
		return GUID_zero();
	}

	return guid;
}

/*
  pull a sid prefix from a objectSid in a result set. 
  this is used to find the domain sid for a user
*/
struct dom_sid *samdb_result_sid_prefix(TALLOC_CTX *mem_ctx, const struct ldb_message *msg, 
					const char *attr)
{
	struct dom_sid *sid = samdb_result_dom_sid(mem_ctx, msg, attr);
	if (!sid || sid->num_auths < 1) return NULL;
	sid->num_auths--;
	return sid;
}

/*
  pull a NTTIME in a result set. 
*/
NTTIME samdb_result_nttime(const struct ldb_message *msg, const char *attr,
			   NTTIME default_value)
{
	return ldb_msg_find_attr_as_uint64(msg, attr, default_value);
}

/*
 * Windows stores 0 for lastLogoff.
 * But when a MS DC return the lastLogoff (as Logoff Time)
 * it returns 0x7FFFFFFFFFFFFFFF, not returning this value in this case
 * cause windows 2008 and newer version to fail for SMB requests
 */
NTTIME samdb_result_last_logoff(const struct ldb_message *msg)
{
	NTTIME ret = ldb_msg_find_attr_as_uint64(msg, "lastLogoff",0);

	if (ret == 0)
		ret = 0x7FFFFFFFFFFFFFFFULL;

	return ret;
}

/*
 * Windows uses both 0 and 9223372036854775807 (0x7FFFFFFFFFFFFFFFULL) to
 * indicate an account doesn't expire.
 *
 * When Windows initially creates an account, it sets
 * accountExpires = 9223372036854775807 (0x7FFFFFFFFFFFFFFF).  However,
 * when changing from an account having a specific expiration date to
 * that account never expiring, it sets accountExpires = 0.
 *
 * Consolidate that logic here to allow clearer logic for account expiry in
 * the rest of the code.
 */
NTTIME samdb_result_account_expires(const struct ldb_message *msg)
{
	NTTIME ret = ldb_msg_find_attr_as_uint64(msg, "accountExpires",
						 0);

	if (ret == 0)
		ret = 0x7FFFFFFFFFFFFFFFULL;

	return ret;
}

/*
  pull a uint64_t from a result set. 
*/
uint64_t samdb_result_uint64(const struct ldb_message *msg, const char *attr,
			     uint64_t default_value)
{
	return ldb_msg_find_attr_as_uint64(msg, attr, default_value);
}


/*
  construct the allow_password_change field from the PwdLastSet attribute and the 
  domain password settings
*/
NTTIME samdb_result_allow_password_change(struct ldb_context *sam_ldb, 
					  TALLOC_CTX *mem_ctx, 
					  struct ldb_dn *domain_dn, 
					  struct ldb_message *msg, 
					  const char *attr)
{
	uint64_t attr_time = samdb_result_uint64(msg, attr, 0);
	int64_t minPwdAge;

	if (attr_time == 0) {
		return 0;
	}

	minPwdAge = samdb_search_int64(sam_ldb, mem_ctx, 0, domain_dn, "minPwdAge", NULL);

	/* yes, this is a -= not a += as minPwdAge is stored as the negative
	   of the number of 100-nano-seconds */
	attr_time -= minPwdAge;

	return attr_time;
}

/*
  construct the force_password_change field from the PwdLastSet
  attribute, the userAccountControl and the domain password settings
*/
NTTIME samdb_result_force_password_change(struct ldb_context *sam_ldb, 
					  TALLOC_CTX *mem_ctx, 
					  struct ldb_dn *domain_dn, 
					  struct ldb_message *msg)
{
	uint64_t attr_time = samdb_result_uint64(msg, "pwdLastSet", 0);
	uint32_t userAccountControl = samdb_result_uint64(msg, "userAccountControl", 0);
	int64_t maxPwdAge;

	/* Machine accounts don't expire, and there is a flag for 'no expiry' */
	if (!(userAccountControl & UF_NORMAL_ACCOUNT)
	    || (userAccountControl & UF_DONT_EXPIRE_PASSWD)) {
		return 0x7FFFFFFFFFFFFFFFULL;
	}

	if (attr_time == 0) {
		return 0;
	}

	maxPwdAge = samdb_search_int64(sam_ldb, mem_ctx, 0, domain_dn, "maxPwdAge", NULL);
	if (maxPwdAge == 0) {
		return 0x7FFFFFFFFFFFFFFFULL;
	} else {
		attr_time -= maxPwdAge;
	}

	return attr_time;
}

/*
  pull a samr_Password structutre from a result set. 
*/
struct samr_Password *samdb_result_hash(TALLOC_CTX *mem_ctx, const struct ldb_message *msg, const char *attr)
{
	struct samr_Password *hash = NULL;
	const struct ldb_val *val = ldb_msg_find_ldb_val(msg, attr);
	if (val && (val->length >= sizeof(hash->hash))) {
		hash = talloc(mem_ctx, struct samr_Password);
		memcpy(hash->hash, val->data, MIN(val->length, sizeof(hash->hash)));
	}
	return hash;
}

/*
  pull an array of samr_Password structutres from a result set. 
*/
uint_t samdb_result_hashes(TALLOC_CTX *mem_ctx, const struct ldb_message *msg, 
			   const char *attr, struct samr_Password **hashes)
{
	uint_t count, i;
	const struct ldb_val *val = ldb_msg_find_ldb_val(msg, attr);

	*hashes = NULL;
	if (!val) {
		return 0;
	}
	count = val->length / 16;
	if (count == 0) {
		return 0;
	}

	*hashes = talloc_array(mem_ctx, struct samr_Password, count);
	if (! *hashes) {
		return 0;
	}

	for (i=0;i<count;i++) {
		memcpy((*hashes)[i].hash, (i*16)+(char *)val->data, 16);
	}

	return count;
}

NTSTATUS samdb_result_passwords(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx, struct ldb_message *msg, 
				struct samr_Password **lm_pwd, struct samr_Password **nt_pwd) 
{
	struct samr_Password *lmPwdHash, *ntPwdHash;
	if (nt_pwd) {
		int num_nt;
		num_nt = samdb_result_hashes(mem_ctx, msg, "unicodePwd", &ntPwdHash);
		if (num_nt == 0) {
			*nt_pwd = NULL;
		} else if (num_nt > 1) {
			return NT_STATUS_INTERNAL_DB_CORRUPTION;
		} else {
			*nt_pwd = &ntPwdHash[0];
		}
	}
	if (lm_pwd) {
		/* Ensure that if we have turned off LM
		 * authentication, that we never use the LM hash, even
		 * if we store it */
		if (lp_lanman_auth(lp_ctx)) {
			int num_lm;
			num_lm = samdb_result_hashes(mem_ctx, msg, "dBCSPwd", &lmPwdHash);
			if (num_lm == 0) {
				*lm_pwd = NULL;
			} else if (num_lm > 1) {
				return NT_STATUS_INTERNAL_DB_CORRUPTION;
			} else {
				*lm_pwd = &lmPwdHash[0];
			}
		} else {
			*lm_pwd = NULL;
		}
	}
	return NT_STATUS_OK;
}

/*
  pull a samr_LogonHours structutre from a result set. 
*/
struct samr_LogonHours samdb_result_logon_hours(TALLOC_CTX *mem_ctx, struct ldb_message *msg, const char *attr)
{
	struct samr_LogonHours hours;
	const int units_per_week = 168;
	const struct ldb_val *val = ldb_msg_find_ldb_val(msg, attr);
	ZERO_STRUCT(hours);
	hours.bits = talloc_array(mem_ctx, uint8_t, units_per_week);
	if (!hours.bits) {
		return hours;
	}
	hours.units_per_week = units_per_week;
	memset(hours.bits, 0xFF, units_per_week);
	if (val) {
		memcpy(hours.bits, val->data, MIN(val->length, units_per_week));
	}
	return hours;
}

/*
  pull a set of account_flags from a result set. 

  This requires that the attributes: 
   pwdLastSet
   userAccountControl
  be included in 'msg'
*/
uint32_t samdb_result_acct_flags(struct ldb_context *sam_ctx, TALLOC_CTX *mem_ctx, 
				 struct ldb_message *msg, struct ldb_dn *domain_dn)
{
	uint32_t userAccountControl = ldb_msg_find_attr_as_uint(msg, "userAccountControl", 0);
	uint32_t acct_flags = ds_uf2acb(userAccountControl);
	NTTIME must_change_time;
	NTTIME now;

	must_change_time = samdb_result_force_password_change(sam_ctx, mem_ctx, 
							      domain_dn, msg);

	/* Test account expire time */
	unix_to_nt_time(&now, time(NULL));
	/* check for expired password */
	if (must_change_time < now) {
		acct_flags |= ACB_PW_EXPIRED;
	}
	return acct_flags;
}

struct lsa_BinaryString samdb_result_parameters(TALLOC_CTX *mem_ctx,
						struct ldb_message *msg,
						const char *attr)
{
	struct lsa_BinaryString s;
	const struct ldb_val *val = ldb_msg_find_ldb_val(msg, attr);

	ZERO_STRUCT(s);

	if (!val) {
		return s;
	}

	s.array = talloc_array(mem_ctx, uint16_t, val->length/2);
	if (!s.array) {
		return s;
	}
	s.length = s.size = val->length/2;
	memcpy(s.array, val->data, val->length);

	return s;
}

/* Find an attribute, with a particular value */

/* The current callers of this function expect a very specific
 * behaviour: In particular, objectClass subclass equivilance is not
 * wanted.  This means that we should not lookup the schema for the
 * comparison function */
struct ldb_message_element *samdb_find_attribute(struct ldb_context *ldb, 
						 const struct ldb_message *msg, 
						 const char *name, const char *value)
{
	int i;
	struct ldb_message_element *el = ldb_msg_find_element(msg, name);

	if (!el) {
		return NULL;
	}

	for (i=0;i<el->num_values;i++) {
		if (ldb_attr_cmp(value, (char *)el->values[i].data) == 0) {
			return el;
		}
	}

	return NULL;
}

int samdb_find_or_add_value(struct ldb_context *ldb, struct ldb_message *msg, const char *name, const char *set_value)
{
	if (samdb_find_attribute(ldb, msg, name, set_value) == NULL) {
		return samdb_msg_add_string(ldb, msg, msg, name, set_value);
	}
	return LDB_SUCCESS;
}

int samdb_find_or_add_attribute(struct ldb_context *ldb, struct ldb_message *msg, const char *name, const char *set_value)
{
	struct ldb_message_element *el;

       	el = ldb_msg_find_element(msg, name);
	if (el) {
		return LDB_SUCCESS;
	}

	return samdb_msg_add_string(ldb, msg, msg, name, set_value);
}



/*
  add a string element to a message
*/
int samdb_msg_add_string(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			 const char *attr_name, const char *str)
{
	char *s = talloc_strdup(mem_ctx, str);
	char *a = talloc_strdup(mem_ctx, attr_name);
	if (s == NULL || a == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
	return ldb_msg_add_string(msg, a, s);
}

/*
  add a dom_sid element to a message
*/
int samdb_msg_add_dom_sid(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			 const char *attr_name, struct dom_sid *sid)
{
	struct ldb_val v;
	enum ndr_err_code ndr_err;

	ndr_err = ndr_push_struct_blob(&v, mem_ctx, 
				       lp_iconv_convenience(ldb_get_opaque(sam_ldb, "loadparm")),
				       sid,
				       (ndr_push_flags_fn_t)ndr_push_dom_sid);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		return -1;
	}
	return ldb_msg_add_value(msg, attr_name, &v, NULL);
}


/*
  add a delete element operation to a message
*/
int samdb_msg_add_delete(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			 const char *attr_name)
{
	/* we use an empty replace rather than a delete, as it allows for 
	   samdb_replace() to be used everywhere */
	return ldb_msg_add_empty(msg, attr_name, LDB_FLAG_MOD_REPLACE, NULL);
}

/*
  add a add attribute value to a message
*/
int samdb_msg_add_addval(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			 const char *attr_name, const char *value)
{
	struct ldb_message_element *el;
	char *a, *v;
	int ret;
	a = talloc_strdup(mem_ctx, attr_name);
	if (a == NULL)
		return -1;
	v = talloc_strdup(mem_ctx, value);
	if (v == NULL)
		return -1;
	ret = ldb_msg_add_string(msg, a, v);
	if (ret != 0)
		return ret;
	el = ldb_msg_find_element(msg, a);
	if (el == NULL)
		return -1;
	el->flags = LDB_FLAG_MOD_ADD;
	return 0;
}

/*
  add a delete attribute value to a message
*/
int samdb_msg_add_delval(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			 const char *attr_name, const char *value)
{
	struct ldb_message_element *el;
	char *a, *v;
	int ret;
	a = talloc_strdup(mem_ctx, attr_name);
	if (a == NULL)
		return -1;
	v = talloc_strdup(mem_ctx, value);
	if (v == NULL)
		return -1;
	ret = ldb_msg_add_string(msg, a, v);
	if (ret != 0)
		return ret;
	el = ldb_msg_find_element(msg, a);
	if (el == NULL)
		return -1;
	el->flags = LDB_FLAG_MOD_DELETE;
	return 0;
}

/*
  add a int element to a message
*/
int samdb_msg_add_int(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
		       const char *attr_name, int v)
{
	const char *s = talloc_asprintf(mem_ctx, "%d", v);
	return samdb_msg_add_string(sam_ldb, mem_ctx, msg, attr_name, s);
}

/*
  add a uint_t element to a message
*/
int samdb_msg_add_uint(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
		       const char *attr_name, uint_t v)
{
	const char *s = talloc_asprintf(mem_ctx, "%u", v);
	return samdb_msg_add_string(sam_ldb, mem_ctx, msg, attr_name, s);
}

/*
  add a (signed) int64_t element to a message
*/
int samdb_msg_add_int64(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			const char *attr_name, int64_t v)
{
	const char *s = talloc_asprintf(mem_ctx, "%lld", (long long)v);
	return samdb_msg_add_string(sam_ldb, mem_ctx, msg, attr_name, s);
}

/*
  add a uint64_t element to a message
*/
int samdb_msg_add_uint64(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			const char *attr_name, uint64_t v)
{
	const char *s = talloc_asprintf(mem_ctx, "%llu", (unsigned long long)v);
	return samdb_msg_add_string(sam_ldb, mem_ctx, msg, attr_name, s);
}

/*
  add a samr_Password element to a message
*/
int samdb_msg_add_hash(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
		       const char *attr_name, struct samr_Password *hash)
{
	struct ldb_val val;
	val.data = talloc_memdup(mem_ctx, hash->hash, 16);
	if (!val.data) {
		return -1;
	}
	val.length = 16;
	return ldb_msg_add_value(msg, attr_name, &val, NULL);
}

/*
  add a samr_Password array to a message
*/
int samdb_msg_add_hashes(TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			 const char *attr_name, struct samr_Password *hashes, uint_t count)
{
	struct ldb_val val;
	int i;
	val.data = talloc_array_size(mem_ctx, 16, count);
	val.length = count*16;
	if (!val.data) {
		return -1;
	}
	for (i=0;i<count;i++) {
		memcpy(i*16 + (char *)val.data, hashes[i].hash, 16);
	}
	return ldb_msg_add_value(msg, attr_name, &val, NULL);
}

/*
  add a acct_flags element to a message
*/
int samdb_msg_add_acct_flags(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			     const char *attr_name, uint32_t v)
{
	return samdb_msg_add_uint(sam_ldb, mem_ctx, msg, attr_name, ds_acb2uf(v));
}

/*
  add a logon_hours element to a message
*/
int samdb_msg_add_logon_hours(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			      const char *attr_name, struct samr_LogonHours *hours)
{
	struct ldb_val val;
	val.length = hours->units_per_week / 8;
	val.data = hours->bits;
	return ldb_msg_add_value(msg, attr_name, &val, NULL);
}

/*
  add a parameters element to a message
*/
int samdb_msg_add_parameters(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			     const char *attr_name, struct lsa_BinaryString *parameters)
{
	struct ldb_val val;
	val.length = parameters->length * 2;
	val.data = (uint8_t *)parameters->array;
	return ldb_msg_add_value(msg, attr_name, &val, NULL);
}
/*
  add a general value element to a message
*/
int samdb_msg_add_value(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			      const char *attr_name, const struct ldb_val *val)
{
	return ldb_msg_add_value(msg, attr_name, val, NULL);
}

/*
  sets a general value element to a message
*/
int samdb_msg_set_value(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			const char *attr_name, const struct ldb_val *val)
{
	struct ldb_message_element *el;

	el = ldb_msg_find_element(msg, attr_name);
	if (el) {
		el->num_values = 0;
	}
	return ldb_msg_add_value(msg, attr_name, val, NULL);
}

/*
  set a string element in a message
*/
int samdb_msg_set_string(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg,
			 const char *attr_name, const char *str)
{
	struct ldb_message_element *el;

	el = ldb_msg_find_element(msg, attr_name);
	if (el) {
		el->num_values = 0;
	}
	return samdb_msg_add_string(sam_ldb, mem_ctx, msg, attr_name, str);
}

/*
  replace elements in a record
*/
int samdb_replace(struct ldb_context *sam_ldb, TALLOC_CTX *mem_ctx, struct ldb_message *msg)
{
	int i;

	/* mark all the message elements as LDB_FLAG_MOD_REPLACE */
	for (i=0;i<msg->num_elements;i++) {
		msg->elements[i].flags = LDB_FLAG_MOD_REPLACE;
	}

	/* modify the samdb record */
	return ldb_modify(sam_ldb, msg);
}

/*
 * Handle ldb_request in transaction
 */
static int dsdb_autotransaction_request(struct ldb_context *sam_ldb,
				 struct ldb_request *req)
{
	int ret;

	ret = ldb_transaction_start(sam_ldb);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	ret = ldb_request(sam_ldb, req);
	if (ret == LDB_SUCCESS) {
		ret = ldb_wait(req->handle, LDB_WAIT_ALL);
	}

	if (ret == LDB_SUCCESS) {
		return ldb_transaction_commit(sam_ldb);
	}
	ldb_transaction_cancel(sam_ldb);

	return ret;
}

/*
 * replace elements in a record using LDB_CONTROL_AS_SYSTEM
 * used to skip access checks on operations
 * that are performed by the system
 */
int samdb_replace_as_system(struct ldb_context *sam_ldb,
			    TALLOC_CTX *mem_ctx,
			    struct ldb_message *msg)
{
	int i;
	int ldb_ret;
	struct ldb_request *req = NULL;

	/* mark all the message elements as LDB_FLAG_MOD_REPLACE */
	for (i=0;i<msg->num_elements;i++) {
		msg->elements[i].flags = LDB_FLAG_MOD_REPLACE;
	}


	ldb_ret = ldb_msg_sanity_check(sam_ldb, msg);
	if (ldb_ret != LDB_SUCCESS) {
		return ldb_ret;
	}

	ldb_ret = ldb_build_mod_req(&req, sam_ldb, mem_ctx,
	                            msg,
	                            NULL,
	                            NULL,
	                            ldb_op_default_callback,
	                            NULL);

	if (ldb_ret != LDB_SUCCESS) {
		talloc_free(req);
		return ldb_ret;
	}

	ldb_ret = ldb_request_add_control(req, LDB_CONTROL_AS_SYSTEM_OID, false, NULL);
	if (ldb_ret != LDB_SUCCESS) {
		talloc_free(req);
		return ldb_ret;
	}

	/* do request and auto start a transaction */
	ldb_ret = dsdb_autotransaction_request(sam_ldb, req);

	talloc_free(req);
	return ldb_ret;
}

/*
  return a default security descriptor
*/
struct security_descriptor *samdb_default_security_descriptor(TALLOC_CTX *mem_ctx)
{
	struct security_descriptor *sd;

	sd = security_descriptor_initialise(mem_ctx);

	return sd;
}

struct ldb_dn *samdb_base_dn(struct ldb_context *sam_ctx) 
{
	return ldb_get_default_basedn(sam_ctx);
}

struct ldb_dn *samdb_config_dn(struct ldb_context *sam_ctx) 
{
	return ldb_get_config_basedn(sam_ctx);
}

struct ldb_dn *samdb_schema_dn(struct ldb_context *sam_ctx) 
{
	return ldb_get_schema_basedn(sam_ctx);
}

struct ldb_dn *samdb_aggregate_schema_dn(struct ldb_context *sam_ctx, TALLOC_CTX *mem_ctx) 
{
	struct ldb_dn *schema_dn = ldb_get_schema_basedn(sam_ctx);
	struct ldb_dn *aggregate_dn;
	if (!schema_dn) {
		return NULL;
	}

	aggregate_dn = ldb_dn_copy(mem_ctx, schema_dn);
	if (!aggregate_dn) {
		return NULL;
	}
	if (!ldb_dn_add_child_fmt(aggregate_dn, "CN=Aggregate")) {
		return NULL;
	}
	return aggregate_dn;
}

struct ldb_dn *samdb_root_dn(struct ldb_context *sam_ctx) 
{
	return ldb_get_root_basedn(sam_ctx);
}

struct ldb_dn *samdb_partitions_dn(struct ldb_context *sam_ctx, TALLOC_CTX *mem_ctx)
{
	struct ldb_dn *new_dn;

	new_dn = ldb_dn_copy(mem_ctx, samdb_config_dn(sam_ctx));
	if ( ! ldb_dn_add_child_fmt(new_dn, "CN=Partitions")) {
		talloc_free(new_dn);
		return NULL;
	}
	return new_dn;
}

struct ldb_dn *samdb_sites_dn(struct ldb_context *sam_ctx, TALLOC_CTX *mem_ctx)
{
	struct ldb_dn *new_dn;

	new_dn = ldb_dn_copy(mem_ctx, samdb_config_dn(sam_ctx));
	if ( ! ldb_dn_add_child_fmt(new_dn, "CN=Sites")) {
		talloc_free(new_dn);
		return NULL;
	}
	return new_dn;
}

/*
  work out the domain sid for the current open ldb
*/
const struct dom_sid *samdb_domain_sid(struct ldb_context *ldb)
{
	TALLOC_CTX *tmp_ctx;
	const struct dom_sid *domain_sid;
	const char *attrs[] = {
		"objectSid",
		NULL
	};
	struct ldb_result *res;
	int ret;

	/* see if we have a cached copy */
	domain_sid = (struct dom_sid *)ldb_get_opaque(ldb, "cache.domain_sid");
	if (domain_sid) {
		return domain_sid;
	}

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		goto failed;
	}

	ret = ldb_search(ldb, tmp_ctx, &res, ldb_get_default_basedn(ldb), LDB_SCOPE_BASE, attrs, "objectSid=*");

	if (ret != LDB_SUCCESS) {
		goto failed;
	}

	if (res->count != 1) {
		goto failed;
	}

	domain_sid = samdb_result_dom_sid(tmp_ctx, res->msgs[0], "objectSid");
	if (domain_sid == NULL) {
		goto failed;
	}

	/* cache the domain_sid in the ldb */
	if (ldb_set_opaque(ldb, "cache.domain_sid", discard_const_p(struct dom_sid, domain_sid)) != LDB_SUCCESS) {
		goto failed;
	}

	talloc_steal(ldb, domain_sid);
	talloc_free(tmp_ctx);

	return domain_sid;

failed:
	DEBUG(1,("Failed to find domain_sid for open ldb\n"));
	talloc_free(tmp_ctx);
	return NULL;
}

bool samdb_set_domain_sid(struct ldb_context *ldb, const struct dom_sid *dom_sid_in)
{
	TALLOC_CTX *tmp_ctx;
	struct dom_sid *dom_sid_new;
	struct dom_sid *dom_sid_old;

	/* see if we have a cached copy */
	dom_sid_old = talloc_get_type(ldb_get_opaque(ldb, 
						     "cache.domain_sid"), struct dom_sid);

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		goto failed;
	}

	dom_sid_new = dom_sid_dup(tmp_ctx, dom_sid_in);
	if (!dom_sid_new) {
		goto failed;
	}

	/* cache the domain_sid in the ldb */
	if (ldb_set_opaque(ldb, "cache.domain_sid", dom_sid_new) != LDB_SUCCESS) {
		goto failed;
	}

	talloc_steal(ldb, dom_sid_new);
	talloc_free(tmp_ctx);
	talloc_free(dom_sid_old);

	return true;

failed:
	DEBUG(1,("Failed to set our own cached domain SID in the ldb!\n"));
	talloc_free(tmp_ctx);
	return false;
}

/* Obtain the short name of the flexible single master operator
 * (FSMO), such as the PDC Emulator */
const char *samdb_result_fsmo_name(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const struct ldb_message *msg, 
			     const char *attr)
{
	/* Format is cn=NTDS Settings,cn=<NETBIOS name of FSMO>,.... */
	struct ldb_dn *fsmo_dn = ldb_msg_find_attr_as_dn(ldb, mem_ctx, msg, attr);
	const struct ldb_val *val = ldb_dn_get_component_val(fsmo_dn, 1);
	const char *name = ldb_dn_get_component_name(fsmo_dn, 1);

	if (!name || (ldb_attr_cmp(name, "cn") != 0)) {
		/* Ensure this matches the format.  This gives us a
		 * bit more confidence that a 'cn' value will be a
		 * ascii string */
		return NULL;
	}
	if (val) {
		return (char *)val->data;
	}
	return NULL;
}

/*
  work out the ntds settings dn for the current open ldb
*/
struct ldb_dn *samdb_ntds_settings_dn(struct ldb_context *ldb)
{
	TALLOC_CTX *tmp_ctx;
	const char *root_attrs[] = { "dsServiceName", NULL };
	int ret;
	struct ldb_result *root_res;
	struct ldb_dn *settings_dn;

	/* see if we have a cached copy */
	settings_dn = (struct ldb_dn *)ldb_get_opaque(ldb, "cache.settings_dn");
	if (settings_dn) {
		return settings_dn;
	}

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		goto failed;
	}

	ret = ldb_search(ldb, tmp_ctx, &root_res, ldb_dn_new(tmp_ctx, ldb, ""), LDB_SCOPE_BASE, root_attrs, NULL);
	if (ret) {
		DEBUG(1,("Searching for dsServiceName in rootDSE failed: %s\n", 
			 ldb_errstring(ldb)));
		goto failed;
	}

	if (root_res->count != 1) {
		goto failed;
	}

	settings_dn = ldb_msg_find_attr_as_dn(ldb, tmp_ctx, root_res->msgs[0], "dsServiceName");

	/* cache the domain_sid in the ldb */
	if (ldb_set_opaque(ldb, "cache.settings_dn", settings_dn) != LDB_SUCCESS) {
		goto failed;
	}

	talloc_steal(ldb, settings_dn);
	talloc_free(tmp_ctx);

	return settings_dn;

failed:
	DEBUG(1,("Failed to find our own NTDS Settings DN in the ldb!\n"));
	talloc_free(tmp_ctx);
	return NULL;
}

/*
  work out the ntds settings invocationId for the current open ldb
*/
const struct GUID *samdb_ntds_invocation_id(struct ldb_context *ldb)
{
	TALLOC_CTX *tmp_ctx;
	const char *attrs[] = { "invocationId", NULL };
	int ret;
	struct ldb_result *res;
	struct GUID *invocation_id;

	/* see if we have a cached copy */
	invocation_id = (struct GUID *)ldb_get_opaque(ldb, "cache.invocation_id");
	if (invocation_id) {
		return invocation_id;
	}

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		goto failed;
	}

	ret = ldb_search(ldb, tmp_ctx, &res, samdb_ntds_settings_dn(ldb), LDB_SCOPE_BASE, attrs, NULL);
	if (ret) {
		goto failed;
	}

	if (res->count != 1) {
		goto failed;
	}

	invocation_id = talloc(tmp_ctx, struct GUID);
	if (!invocation_id) {
		goto failed;
	}

	*invocation_id = samdb_result_guid(res->msgs[0], "invocationId");

	/* cache the domain_sid in the ldb */
	if (ldb_set_opaque(ldb, "cache.invocation_id", invocation_id) != LDB_SUCCESS) {
		goto failed;
	}

	talloc_steal(ldb, invocation_id);
	talloc_free(tmp_ctx);

	return invocation_id;

failed:
	DEBUG(1,("Failed to find our own NTDS Settings invocationId in the ldb!\n"));
	talloc_free(tmp_ctx);
	return NULL;
}

bool samdb_set_ntds_invocation_id(struct ldb_context *ldb, const struct GUID *invocation_id_in)
{
	TALLOC_CTX *tmp_ctx;
	struct GUID *invocation_id_new;
	struct GUID *invocation_id_old;

	/* see if we have a cached copy */
	invocation_id_old = (struct GUID *)ldb_get_opaque(ldb, 
							 "cache.invocation_id");

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		goto failed;
	}

	invocation_id_new = talloc(tmp_ctx, struct GUID);
	if (!invocation_id_new) {
		goto failed;
	}

	*invocation_id_new = *invocation_id_in;

	/* cache the domain_sid in the ldb */
	if (ldb_set_opaque(ldb, "cache.invocation_id", invocation_id_new) != LDB_SUCCESS) {
		goto failed;
	}

	talloc_steal(ldb, invocation_id_new);
	talloc_free(tmp_ctx);
	talloc_free(invocation_id_old);

	return true;

failed:
	DEBUG(1,("Failed to set our own cached invocationId in the ldb!\n"));
	talloc_free(tmp_ctx);
	return false;
}

/*
  work out the ntds settings objectGUID for the current open ldb
*/
const struct GUID *samdb_ntds_objectGUID(struct ldb_context *ldb)
{
	TALLOC_CTX *tmp_ctx;
	const char *attrs[] = { "objectGUID", NULL };
	int ret;
	struct ldb_result *res;
	struct GUID *ntds_guid;

	/* see if we have a cached copy */
	ntds_guid = (struct GUID *)ldb_get_opaque(ldb, "cache.ntds_guid");
	if (ntds_guid) {
		return ntds_guid;
	}

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		goto failed;
	}

	ret = ldb_search(ldb, tmp_ctx, &res, samdb_ntds_settings_dn(ldb), LDB_SCOPE_BASE, attrs, NULL);
	if (ret) {
		goto failed;
	}

	if (res->count != 1) {
		goto failed;
	}

	ntds_guid = talloc(tmp_ctx, struct GUID);
	if (!ntds_guid) {
		goto failed;
	}

	*ntds_guid = samdb_result_guid(res->msgs[0], "objectGUID");

	/* cache the domain_sid in the ldb */
	if (ldb_set_opaque(ldb, "cache.ntds_guid", ntds_guid) != LDB_SUCCESS) {
		goto failed;
	}

	talloc_steal(ldb, ntds_guid);
	talloc_free(tmp_ctx);

	return ntds_guid;

failed:
	DEBUG(1,("Failed to find our own NTDS Settings objectGUID in the ldb!\n"));
	talloc_free(tmp_ctx);
	return NULL;
}

bool samdb_set_ntds_objectGUID(struct ldb_context *ldb, const struct GUID *ntds_guid_in)
{
	TALLOC_CTX *tmp_ctx;
	struct GUID *ntds_guid_new;
	struct GUID *ntds_guid_old;

	/* see if we have a cached copy */
	ntds_guid_old = (struct GUID *)ldb_get_opaque(ldb, "cache.ntds_guid");

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		goto failed;
	}

	ntds_guid_new = talloc(tmp_ctx, struct GUID);
	if (!ntds_guid_new) {
		goto failed;
	}

	*ntds_guid_new = *ntds_guid_in;

	/* cache the domain_sid in the ldb */
	if (ldb_set_opaque(ldb, "cache.ntds_guid", ntds_guid_new) != LDB_SUCCESS) {
		goto failed;
	}

	talloc_steal(ldb, ntds_guid_new);
	talloc_free(tmp_ctx);
	talloc_free(ntds_guid_old);

	return true;

failed:
	DEBUG(1,("Failed to set our own cached invocationId in the ldb!\n"));
	talloc_free(tmp_ctx);
	return false;
}

/*
  work out the server dn for the current open ldb
*/
struct ldb_dn *samdb_server_dn(struct ldb_context *ldb, TALLOC_CTX *mem_ctx)
{
	return ldb_dn_get_parent(mem_ctx, samdb_ntds_settings_dn(ldb));
}

/*
  work out the server dn for the current open ldb
*/
struct ldb_dn *samdb_server_site_dn(struct ldb_context *ldb, TALLOC_CTX *mem_ctx)
{
	struct ldb_dn *server_dn;
	struct ldb_dn *server_site_dn;

	server_dn = samdb_server_dn(ldb, mem_ctx);
	if (!server_dn) return NULL;

	server_site_dn = ldb_dn_get_parent(mem_ctx, server_dn);

	talloc_free(server_dn);
	return server_site_dn;
}

const char *samdb_server_site_name(struct ldb_context *ldb, TALLOC_CTX *mem_ctx)
{
	const struct ldb_val *val = ldb_dn_get_rdn_val(samdb_server_site_dn(ldb, mem_ctx));

	if (val != NULL)
		return (const char *) val->data;
	else
		return NULL;
}

/*
  work out if we are the PDC for the domain of the current open ldb
*/
bool samdb_is_pdc(struct ldb_context *ldb)
{
	const char *dom_attrs[] = { "fSMORoleOwner", NULL };
	int ret;
	struct ldb_result *dom_res;
	TALLOC_CTX *tmp_ctx;
	bool is_pdc;
	struct ldb_dn *pdc;

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		DEBUG(1, ("talloc_new failed in samdb_is_pdc"));
		return false;
	}

	ret = ldb_search(ldb, tmp_ctx, &dom_res, ldb_get_default_basedn(ldb), LDB_SCOPE_BASE, dom_attrs, NULL);
	if (ret) {
		DEBUG(1,("Searching for fSMORoleOwner in %s failed: %s\n", 
			 ldb_dn_get_linearized(ldb_get_default_basedn(ldb)), 
			 ldb_errstring(ldb)));
		goto failed;
	}
	if (dom_res->count != 1) {
		goto failed;
	}

	pdc = ldb_msg_find_attr_as_dn(ldb, tmp_ctx, dom_res->msgs[0], "fSMORoleOwner");

	if (ldb_dn_compare(samdb_ntds_settings_dn(ldb), pdc) == 0) {
		is_pdc = true;
	} else {
		is_pdc = false;
	}

	talloc_free(tmp_ctx);

	return is_pdc;

failed:
	DEBUG(1,("Failed to find if we are the PDC for this ldb\n"));
	talloc_free(tmp_ctx);
	return false;
}

/*
  work out if we are a Global Catalog server for the domain of the current open ldb
*/
bool samdb_is_gc(struct ldb_context *ldb)
{
	const char *attrs[] = { "options", NULL };
	int ret, options;
	struct ldb_result *res;
	TALLOC_CTX *tmp_ctx;

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		DEBUG(1, ("talloc_new failed in samdb_is_pdc"));
		return false;
	}

	/* Query cn=ntds settings,.... */
	ret = ldb_search(ldb, tmp_ctx, &res, samdb_ntds_settings_dn(ldb), LDB_SCOPE_BASE, attrs, NULL);
	if (ret) {
		talloc_free(tmp_ctx);
		return false;
	}
	if (res->count != 1) {
		talloc_free(tmp_ctx);
		return false;
	}

	options = ldb_msg_find_attr_as_int(res->msgs[0], "options", 0);
	talloc_free(tmp_ctx);

	/* if options attribute has the 0x00000001 flag set, then enable the global catlog */
	if (options & 0x000000001) {
		return true;
	}
	return false;
}

/* Find a domain object in the parents of a particular DN.  */
int samdb_search_for_parent_domain(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, struct ldb_dn *dn,
				   struct ldb_dn **parent_dn, const char **errstring)
{
	TALLOC_CTX *local_ctx;
	struct ldb_dn *sdn = dn;
	struct ldb_result *res = NULL;
	int ret = 0;
	const char *attrs[] = { NULL };

	local_ctx = talloc_new(mem_ctx);
	if (local_ctx == NULL) return LDB_ERR_OPERATIONS_ERROR;

	while ((sdn = ldb_dn_get_parent(local_ctx, sdn))) {
		ret = ldb_search(ldb, local_ctx, &res, sdn, LDB_SCOPE_BASE, attrs,
				 "(|(objectClass=domain)(objectClass=builtinDomain))");
		if (ret == LDB_SUCCESS) {
			if (res->count == 1) {
				break;
			}
		} else {
			break;
		}
	}

	if (ret != LDB_SUCCESS) {
		*errstring = talloc_asprintf(mem_ctx, "Error searching for parent domain of %s, failed searching for %s: %s",
					     ldb_dn_get_linearized(dn),
					     ldb_dn_get_linearized(sdn),
					     ldb_errstring(ldb));
		talloc_free(local_ctx);
		return ret;
	}
	if (res->count != 1) {
		*errstring = talloc_asprintf(mem_ctx, "Invalid dn (%s), not child of a domain object",
					     ldb_dn_get_linearized(dn));
		DEBUG(0,(__location__ ": %s\n", *errstring));
		talloc_free(local_ctx);
		return LDB_ERR_CONSTRAINT_VIOLATION;
	}

	*parent_dn = talloc_steal(mem_ctx, res->msgs[0]->dn);
	talloc_free(local_ctx);
	return ret;
}


/*
 * Performs checks on a user password (plaintext UNIX format - attribute
 * "password"). The remaining parameters have to be extracted from the domain
 * object in the AD.
 *
 * Result codes from "enum samr_ValidationStatus" (consider "samr.idl")
 */
enum samr_ValidationStatus samdb_check_password(const DATA_BLOB *password,
						const uint32_t pwdProperties,
						const uint32_t minPwdLength)
{
	/* checks if the "minPwdLength" property is satisfied */
	if (minPwdLength > password->length)
		return SAMR_VALIDATION_STATUS_PWD_TOO_SHORT;

	/* checks the password complexity */
	if (((pwdProperties & DOMAIN_PASSWORD_COMPLEX) != 0)
			&& (password->data != NULL)
			&& (!check_password_quality((const char *) password->data)))
		return SAMR_VALIDATION_STATUS_NOT_COMPLEX_ENOUGH;

	return SAMR_VALIDATION_STATUS_SUCCESS;
}

/*
 * Sets the user password using plaintext UTF16 (attribute "new_password") or
 * LM (attribute "lmNewHash") or NT (attribute "ntNewHash") hash. Also pass
 * as parameter if it's a user change or not ("userChange"). The "rejectReason"
 * gives some more informations if the changed failed.
 *
 * The caller should have a LDB transaction wrapping this.
 *
 * Results: NT_STATUS_OK, NT_STATUS_INTERNAL_DB_CORRUPTION,
 *   NT_STATUS_INVALID_PARAMETER, NT_STATUS_UNSUCCESSFUL,
 *   NT_STATUS_PASSWORD_RESTRICTION
 */
NTSTATUS samdb_set_password(struct ldb_context *ctx, TALLOC_CTX *mem_ctx,
			    struct ldb_dn *user_dn, struct ldb_dn *domain_dn,
			    struct ldb_message *mod,
			    const DATA_BLOB *new_password,
			    struct samr_Password *param_lmNewHash,
			    struct samr_Password *param_ntNewHash,
			    bool user_change,
			    enum samPwdChangeReason *reject_reason,
			    struct samr_DomInfo1 **_dominfo)
{
	const char * const user_attrs[] = { "userAccountControl",
					    "lmPwdHistory",
					    "ntPwdHistory", 
					    "dBCSPwd", "unicodePwd", 
					    "objectSid", 
					    "pwdLastSet", NULL };
	const char * const domain_attrs[] = { "minPwdLength", "pwdProperties",
					      "pwdHistoryLength",
					      "maxPwdAge", "minPwdAge", NULL };
	NTTIME pwdLastSet;
	uint32_t minPwdLength, pwdProperties, pwdHistoryLength;
	int64_t maxPwdAge, minPwdAge;
	uint32_t userAccountControl;
	struct samr_Password *sambaLMPwdHistory, *sambaNTPwdHistory,
		*lmPwdHash, *ntPwdHash, *lmNewHash, *ntNewHash;
	struct samr_Password local_lmNewHash, local_ntNewHash;
	int sambaLMPwdHistory_len, sambaNTPwdHistory_len;
	struct dom_sid *domain_sid;
	struct ldb_message **res;
	bool restrictions;
	int count;
	time_t now = time(NULL);
	NTTIME now_nt;
	int i;

	/* we need to know the time to compute password age */
	unix_to_nt_time(&now_nt, now);

	/* pull all the user parameters */
	count = gendb_search_dn(ctx, mem_ctx, user_dn, &res, user_attrs);
	if (count != 1) {
		return NT_STATUS_INTERNAL_DB_CORRUPTION;
	}
	userAccountControl = samdb_result_uint(res[0], "userAccountControl", 0);
	sambaLMPwdHistory_len = samdb_result_hashes(mem_ctx, res[0],
					 "lmPwdHistory", &sambaLMPwdHistory);
	sambaNTPwdHistory_len = samdb_result_hashes(mem_ctx, res[0],
					 "ntPwdHistory", &sambaNTPwdHistory);
	lmPwdHash = samdb_result_hash(mem_ctx, res[0], "dBCSPwd");
	ntPwdHash = samdb_result_hash(mem_ctx, res[0], "unicodePwd");
	pwdLastSet = samdb_result_uint64(res[0], "pwdLastSet", 0);

	/* Copy parameters */
	lmNewHash = param_lmNewHash;
	ntNewHash = param_ntNewHash;

	/* Only non-trust accounts have restrictions (possibly this
	 * test is the wrong way around, but I like to be restrictive
	 * if possible */
	restrictions = !(userAccountControl & (UF_INTERDOMAIN_TRUST_ACCOUNT
					       |UF_WORKSTATION_TRUST_ACCOUNT
					       |UF_SERVER_TRUST_ACCOUNT)); 

	if (domain_dn != NULL) {
		/* pull the domain parameters */
		count = gendb_search_dn(ctx, mem_ctx, domain_dn, &res,
								domain_attrs);
		if (count != 1) {
			DEBUG(2, ("samdb_set_password: Domain DN %s is invalid, for user %s\n", 
				  ldb_dn_get_linearized(domain_dn),
				  ldb_dn_get_linearized(user_dn)));
			return NT_STATUS_NO_SUCH_DOMAIN;
		}
	} else {
		/* work out the domain sid, and pull the domain from there */
		domain_sid = samdb_result_sid_prefix(mem_ctx, res[0],
								"objectSid");
		if (domain_sid == NULL) {
			return NT_STATUS_INTERNAL_DB_CORRUPTION;
		}

		count = gendb_search(ctx, mem_ctx, NULL, &res, domain_attrs, 
				"(objectSid=%s)",
				ldap_encode_ndr_dom_sid(mem_ctx, domain_sid));
		if (count != 1) {
			DEBUG(2, ("samdb_set_password: Could not find domain to match SID: %s, for user %s\n", 
				  dom_sid_string(mem_ctx, domain_sid),
				  ldb_dn_get_linearized(user_dn)));
			return NT_STATUS_NO_SUCH_DOMAIN;
		}
	}

	minPwdLength = samdb_result_uint(res[0], "minPwdLength", 0);
	pwdProperties = samdb_result_uint(res[0], "pwdProperties", 0);
	pwdHistoryLength = samdb_result_uint(res[0], "pwdHistoryLength", 0);
	maxPwdAge = samdb_result_int64(res[0], "maxPwdAge", 0);
	minPwdAge = samdb_result_int64(res[0], "minPwdAge", 0);

	if ((userAccountControl & UF_PASSWD_NOTREQD) != 0) {
		/* see [MS-ADTS] 2.2.15 */
		minPwdLength = 0;
	}

	if (_dominfo != NULL) {
		struct samr_DomInfo1 *dominfo;
		/* on failure we need to fill in the reject reasons */
		dominfo = talloc(mem_ctx, struct samr_DomInfo1);
		if (dominfo == NULL) {
			return NT_STATUS_NO_MEMORY;
		}
		dominfo->min_password_length     = minPwdLength;
		dominfo->password_properties     = pwdProperties;
		dominfo->password_history_length = pwdHistoryLength;
		dominfo->max_password_age        = maxPwdAge;
		dominfo->min_password_age        = minPwdAge;
		*_dominfo = dominfo;
	}

	if ((restrictions != 0) && (new_password != 0)) {
		char *new_pass;

		/* checks if the "minPwdLength" property is satisfied */
		if ((restrictions != 0)
			&& (minPwdLength > utf16_len_n(
				new_password->data, new_password->length)/2)) {
			if (reject_reason) {
				*reject_reason = SAM_PWD_CHANGE_PASSWORD_TOO_SHORT;
			}
			return NT_STATUS_PASSWORD_RESTRICTION;
		}

		/* Create the NT hash */
		mdfour(local_ntNewHash.hash, new_password->data,
							new_password->length);

		ntNewHash = &local_ntNewHash;

		/* Only check complexity if we can convert it at all.  Assuming unconvertable passwords are 'strong' */
		if (convert_string_talloc_convenience(mem_ctx,
			  lp_iconv_convenience(ldb_get_opaque(ctx, "loadparm")),
			  CH_UTF16, CH_UNIX,
			  new_password->data, new_password->length,
			  (void **)&new_pass, NULL, false)) {

			/* checks the password complexity */
			if ((restrictions != 0)
				&& ((pwdProperties
					& DOMAIN_PASSWORD_COMPLEX) != 0)
				&& (!check_password_quality(new_pass))) {
				if (reject_reason) {
					*reject_reason = SAM_PWD_CHANGE_NOT_COMPLEX;
				}
				return NT_STATUS_PASSWORD_RESTRICTION;
			}

			/* compute the new lm hashes (for checking history - case insenitivly!) */
			if (E_deshash(new_pass, local_lmNewHash.hash)) {
				lmNewHash = &local_lmNewHash;
			}
		}
	}

	if ((restrictions != 0) && user_change) {
		/* are all password changes disallowed? */
		if ((pwdProperties & DOMAIN_REFUSE_PASSWORD_CHANGE) != 0) {
			if (reject_reason) {
				*reject_reason = SAM_PWD_CHANGE_NO_ERROR;
			}
			return NT_STATUS_PASSWORD_RESTRICTION;
		}

		/* can this user change the password? */
		if ((userAccountControl & UF_PASSWD_CANT_CHANGE) != 0) {
			if (reject_reason) {
				*reject_reason = SAM_PWD_CHANGE_NO_ERROR;
			}
			return NT_STATUS_PASSWORD_RESTRICTION;
		}

		/* Password minimum age: yes, this is a minus. The ages are in negative 100nsec units! */
		if (pwdLastSet - minPwdAge > now_nt) {
			if (reject_reason) {
				*reject_reason = SAM_PWD_CHANGE_NO_ERROR;
			}
			return NT_STATUS_PASSWORD_RESTRICTION;
		}

		/* check the immediately past password */
		if (pwdHistoryLength > 0) {
			if (lmNewHash && lmPwdHash && memcmp(lmNewHash->hash,
					lmPwdHash->hash, 16) == 0) {
				if (reject_reason) {
					*reject_reason = SAM_PWD_CHANGE_PWD_IN_HISTORY;
				}
				return NT_STATUS_PASSWORD_RESTRICTION;
			}
			if (ntNewHash && ntPwdHash && memcmp(ntNewHash->hash,
					ntPwdHash->hash, 16) == 0) {
				if (reject_reason) {
					*reject_reason = SAM_PWD_CHANGE_PWD_IN_HISTORY;
				}
				return NT_STATUS_PASSWORD_RESTRICTION;
			}
		}

		/* check the password history */
		sambaLMPwdHistory_len = MIN(sambaLMPwdHistory_len,
							pwdHistoryLength);
		sambaNTPwdHistory_len = MIN(sambaNTPwdHistory_len,
							pwdHistoryLength);

		for (i=0; lmNewHash && i<sambaLMPwdHistory_len;i++) {
			if (memcmp(lmNewHash->hash, sambaLMPwdHistory[i].hash,
					16) == 0) {
				if (reject_reason) {
					*reject_reason = SAM_PWD_CHANGE_PWD_IN_HISTORY;
				}
				return NT_STATUS_PASSWORD_RESTRICTION;
			}
		}
		for (i=0; ntNewHash && i<sambaNTPwdHistory_len;i++) {
			if (memcmp(ntNewHash->hash, sambaNTPwdHistory[i].hash,
					 16) == 0) {
				if (reject_reason) {
					*reject_reason = SAM_PWD_CHANGE_PWD_IN_HISTORY;
				}
				return NT_STATUS_PASSWORD_RESTRICTION;
			}
		}
	}

#define CHECK_RET(x) do { if (x != 0) return NT_STATUS_NO_MEMORY; } while(0)

	/* the password is acceptable. Start forming the new fields */
	if (new_password != NULL) {
		/* if we know the cleartext UTF16 password, then set it.
		 * Modules in ldb will set all the appropriate
		 * hashes */
		CHECK_RET(ldb_msg_add_value(mod, "clearTextPassword", new_password, NULL));
	} else {
		/* we don't have the cleartext, so set what we have of the
		 * hashes */

		if (lmNewHash) {
			CHECK_RET(samdb_msg_add_hash(ctx, mem_ctx, mod, "dBCSPwd", lmNewHash));
		}

		if (ntNewHash) {
			CHECK_RET(samdb_msg_add_hash(ctx, mem_ctx, mod, "unicodePwd", ntNewHash));
		}
	}

	if (reject_reason) {
		*reject_reason = SAM_PWD_CHANGE_NO_ERROR;
	}
	return NT_STATUS_OK;
}


/*
 * Sets the user password using plaintext UTF16 (attribute "new_password") or
 * LM (attribute "lmNewHash") or NT (attribute "ntNewHash") hash. Also pass
 * as parameter if it's a user change or not ("userChange"). The "rejectReason"
 * gives some more informations if the changed failed.
 *
 * This wrapper function for "samdb_set_password" takes a SID as input rather
 * than a user DN.
 *
 * This call encapsulates a new LDB transaction for changing the password;
 * therefore the user hasn't to start a new one.
 *
 * Results: NT_STATUS_OK, NT_STATUS_INTERNAL_DB_CORRUPTION,
 *   NT_STATUS_INVALID_PARAMETER, NT_STATUS_UNSUCCESSFUL,
 *   NT_STATUS_PASSWORD_RESTRICTION
 */
NTSTATUS samdb_set_password_sid(struct ldb_context *ldb, TALLOC_CTX *mem_ctx,
				const struct dom_sid *user_sid,
				const DATA_BLOB *new_password,
				struct samr_Password *lmNewHash, 
				struct samr_Password *ntNewHash,
				bool user_change,
				enum samPwdChangeReason *reject_reason,
				struct samr_DomInfo1 **_dominfo) 
{
	NTSTATUS nt_status;
	struct ldb_dn *user_dn;
	struct ldb_message *msg;
	int ret;

	ret = ldb_transaction_start(ldb);
	if (ret != LDB_SUCCESS) {
		DEBUG(1, ("Failed to start transaction: %s\n", ldb_errstring(ldb)));
		return NT_STATUS_TRANSACTION_ABORTED;
	}

	user_dn = samdb_search_dn(ldb, mem_ctx, NULL,
				  "(&(objectSid=%s)(objectClass=user))", 
				  ldap_encode_ndr_dom_sid(mem_ctx, user_sid));
	if (!user_dn) {
		ldb_transaction_cancel(ldb);
		DEBUG(3, ("samdb_set_password_sid: SID %s not found in samdb, returning NO_SUCH_USER\n",
			  dom_sid_string(mem_ctx, user_sid)));
		return NT_STATUS_NO_SUCH_USER;
	}

	msg = ldb_msg_new(mem_ctx);
	if (msg == NULL) {
		ldb_transaction_cancel(ldb);
		talloc_free(user_dn);
		return NT_STATUS_NO_MEMORY;
	}

	msg->dn = ldb_dn_copy(msg, user_dn);
	if (!msg->dn) {
		ldb_transaction_cancel(ldb);
		talloc_free(user_dn);
		talloc_free(msg);
		return NT_STATUS_NO_MEMORY;
	}

	nt_status = samdb_set_password(ldb, mem_ctx,
				       user_dn, NULL,
				       msg, new_password,
				       lmNewHash, ntNewHash,
				       user_change,
				       reject_reason, _dominfo);
	if (!NT_STATUS_IS_OK(nt_status)) {
		ldb_transaction_cancel(ldb);
		talloc_free(user_dn);
		talloc_free(msg);
		return nt_status;
	}

	/* modify the samdb record */
	ret = samdb_replace(ldb, mem_ctx, msg);
	if (ret != LDB_SUCCESS) {
		ldb_transaction_cancel(ldb);
		talloc_free(user_dn);
		talloc_free(msg);
		return NT_STATUS_ACCESS_DENIED;
	}

	talloc_free(msg);

	ret = ldb_transaction_commit(ldb);
	if (ret != LDB_SUCCESS) {
		DEBUG(0,("Failed to commit transaction to change password on %s: %s\n",
			 ldb_dn_get_linearized(user_dn),
			 ldb_errstring(ldb)));
		talloc_free(user_dn);
		return NT_STATUS_TRANSACTION_ABORTED;
	}

	talloc_free(user_dn);
	return NT_STATUS_OK;
}


NTSTATUS samdb_create_foreign_security_principal(struct ldb_context *sam_ctx, TALLOC_CTX *mem_ctx, 
						 struct dom_sid *sid, struct ldb_dn **ret_dn) 
{
	struct ldb_message *msg;
	struct ldb_dn *basedn;
	const char *sidstr;
	int ret;

	sidstr = dom_sid_string(mem_ctx, sid);
	NT_STATUS_HAVE_NO_MEMORY(sidstr);

	/* We might have to create a ForeignSecurityPrincipal, even if this user
	 * is in our own domain */

	msg = ldb_msg_new(mem_ctx);
	if (msg == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	/* TODO: Hmmm. This feels wrong. How do I find the base dn to
	 * put the ForeignSecurityPrincipals? d_state->domain_dn does
	 * not work, this is wrong for the Builtin domain, there's no
	 * cn=For...,cn=Builtin,dc={BASEDN}.  -- vl
	 */

	basedn = samdb_search_dn(sam_ctx, mem_ctx, NULL,
				 "(&(objectClass=container)(cn=ForeignSecurityPrincipals))");

	if (basedn == NULL) {
		DEBUG(0, ("Failed to find DN for "
			  "ForeignSecurityPrincipal container\n"));
		return NT_STATUS_INTERNAL_DB_CORRUPTION;
	}

	/* add core elements to the ldb_message for the alias */
	msg->dn = ldb_dn_copy(mem_ctx, basedn);
	if ( ! ldb_dn_add_child_fmt(msg->dn, "CN=%s", sidstr))
		return NT_STATUS_NO_MEMORY;

	samdb_msg_add_string(sam_ctx, mem_ctx, msg,
			     "objectClass",
			     "foreignSecurityPrincipal");

	/* create the alias */
	ret = ldb_add(sam_ctx, msg);
	if (ret != 0) {
		DEBUG(0,("Failed to create foreignSecurityPrincipal "
			 "record %s: %s\n", 
			 ldb_dn_get_linearized(msg->dn),
			 ldb_errstring(sam_ctx)));
		return NT_STATUS_INTERNAL_DB_CORRUPTION;
	}
	*ret_dn = msg->dn;
	return NT_STATUS_OK;
}


/*
  Find the DN of a domain, assuming it to be a dotted.dns name
*/

struct ldb_dn *samdb_dns_domain_to_dn(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *dns_domain) 
{
	int i;
	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
	const char *binary_encoded;
	const char **split_realm;
	struct ldb_dn *dn;

	if (!tmp_ctx) {
		return NULL;
	}

	split_realm = (const char **)str_list_make(tmp_ctx, dns_domain, ".");
	if (!split_realm) {
		talloc_free(tmp_ctx);
		return NULL;
	}
	dn = ldb_dn_new(mem_ctx, ldb, NULL);
	for (i=0; split_realm[i]; i++) {
		binary_encoded = ldb_binary_encode_string(tmp_ctx, split_realm[i]);
		if (!ldb_dn_add_base_fmt(dn, "dc=%s", binary_encoded)) {
			DEBUG(2, ("Failed to add dc=%s element to DN %s\n",
				  binary_encoded, ldb_dn_get_linearized(dn)));
			talloc_free(tmp_ctx);
			return NULL;
		}
	}
	if (!ldb_dn_validate(dn)) {
		DEBUG(2, ("Failed to validated DN %s\n",
			  ldb_dn_get_linearized(dn)));
		return NULL;
	}
	return dn;
}
/*
  Find the DN of a domain, be it the netbios or DNS name 
*/

struct ldb_dn *samdb_domain_to_dn(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, 
				  const char *domain_name) 
{
	const char * const domain_ref_attrs[] = {
		"ncName", NULL
	};
	const char * const domain_ref2_attrs[] = {
		NULL
	};
	struct ldb_result *res_domain_ref;
	char *escaped_domain = ldb_binary_encode_string(mem_ctx, domain_name);
	/* find the domain's DN */
	int ret_domain = ldb_search(ldb, mem_ctx,
					    &res_domain_ref, 
					    samdb_partitions_dn(ldb, mem_ctx), 
					    LDB_SCOPE_ONELEVEL, 
					    domain_ref_attrs,
					    "(&(nETBIOSName=%s)(objectclass=crossRef))", 
					    escaped_domain);
	if (ret_domain != 0) {
		return NULL;
	}

	if (res_domain_ref->count == 0) {
		ret_domain = ldb_search(ldb, mem_ctx,
						&res_domain_ref, 
						samdb_dns_domain_to_dn(ldb, mem_ctx, domain_name),
						LDB_SCOPE_BASE,
						domain_ref2_attrs,
						"(objectclass=domain)");
		if (ret_domain != 0) {
			return NULL;
		}

		if (res_domain_ref->count == 1) {
			return res_domain_ref->msgs[0]->dn;
		}
		return NULL;
	}

	if (res_domain_ref->count > 1) {
		DEBUG(0,("Found %d records matching domain [%s]\n", 
			 ret_domain, domain_name));
		return NULL;
	}

	return samdb_result_dn(ldb, mem_ctx, res_domain_ref->msgs[0], "nCName", NULL);

}


/*
  use a GUID to find a DN
 */
int dsdb_find_dn_by_guid(struct ldb_context *ldb, 
			 TALLOC_CTX *mem_ctx,
			 const char *guid_str, struct ldb_dn **dn)
{
	int ret;
	struct ldb_result *res;
	const char *attrs[] = { NULL };
	struct ldb_request *search_req;
	char *expression;
	struct ldb_search_options_control *options;

	expression = talloc_asprintf(mem_ctx, "objectGUID=%s", guid_str);
	if (!expression) {
		DEBUG(0, (__location__ ": out of memory\n"));
		return LDB_ERR_OPERATIONS_ERROR;
	}

	res = talloc_zero(mem_ctx, struct ldb_result);
	if (!res) {
		DEBUG(0, (__location__ ": out of memory\n"));
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ldb_build_search_req(&search_req, ldb, mem_ctx,
				   ldb_get_default_basedn(ldb),
				   LDB_SCOPE_SUBTREE,
				   expression, attrs,
				   NULL,
				   res, ldb_search_default_callback,
				   NULL);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	/* we need to cope with cross-partition links, so search for
	   the GUID over all partitions */
	options = talloc(search_req, struct ldb_search_options_control);
	if (options == NULL) {
		DEBUG(0, (__location__ ": out of memory\n"));
		return LDB_ERR_OPERATIONS_ERROR;
	}
	options->search_options = LDB_SEARCH_OPTION_PHANTOM_ROOT;

	ret = ldb_request_add_control(search_req, LDB_CONTROL_EXTENDED_DN_OID, true, NULL);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	ret = ldb_request_add_control(search_req,
				      LDB_CONTROL_SEARCH_OPTIONS_OID,
				      true, options);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	ret = ldb_request(ldb, search_req);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	ret = ldb_wait(search_req->handle, LDB_WAIT_ALL);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	/* this really should be exactly 1, but there is a bug in the
	   partitions module that can return two here with the
	   search_options control set */
	if (res->count < 1) {
		return LDB_ERR_NO_SUCH_OBJECT;
	}

	*dn = res->msgs[0]->dn;

	return LDB_SUCCESS;
}

/*
  search for attrs on one DN, allowing for deleted objects
 */
int dsdb_search_dn_with_deleted(struct ldb_context *ldb,
				TALLOC_CTX *mem_ctx,
				struct ldb_result **_res,
				struct ldb_dn *basedn,
				const char * const *attrs)
{
	int ret;
	struct ldb_request *req;
	TALLOC_CTX *tmp_ctx;
	struct ldb_result *res;

	tmp_ctx = talloc_new(mem_ctx);

	res = talloc_zero(tmp_ctx, struct ldb_result);
	if (!res) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ldb_build_search_req(&req, ldb, tmp_ctx,
				   basedn,
				   LDB_SCOPE_BASE,
				   NULL,
				   attrs,
				   NULL,
				   res,
				   ldb_search_default_callback,
				   NULL);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}

	ret = ldb_request_add_control(req, LDB_CONTROL_SHOW_DELETED_OID, true, NULL);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	ret = ldb_request(ldb, req);
	if (ret == LDB_SUCCESS) {
		ret = ldb_wait(req->handle, LDB_WAIT_ALL);
	}

	talloc_free(req);
	*_res = talloc_steal(mem_ctx, res);
	return ret;
}


/*
  use a DN to find a GUID
 */
int dsdb_find_guid_by_dn(struct ldb_context *ldb, 
			 struct ldb_dn *dn, struct GUID *guid)
{
	int ret;
	struct ldb_result *res;
	const char *attrs[] = { "objectGUID", NULL };
	TALLOC_CTX *tmp_ctx = talloc_new(ldb);

	ret = dsdb_search_dn_with_deleted(ldb, tmp_ctx, &res, dn, attrs);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}
	if (res->count < 1) {
		talloc_free(tmp_ctx);
		return LDB_ERR_NO_SUCH_OBJECT;
	}
	*guid = samdb_result_guid(res->msgs[0], "objectGUID");
	talloc_free(tmp_ctx);
	return LDB_SUCCESS;
}



/*
 adds the given GUID to the given ldb_message. This value is added
 for the given attr_name (may be either "objectGUID" or "parentGUID").
 */
int dsdb_msg_add_guid(struct ldb_message *msg,
		struct GUID *guid,
		const char *attr_name)
{
	int ret;
	struct ldb_val v;
	NTSTATUS status;
	TALLOC_CTX *tmp_ctx =  talloc_init("dsdb_msg_add_guid");

	status = GUID_to_ndr_blob(guid, tmp_ctx, &v);
	if (!NT_STATUS_IS_OK(status)) {
		ret = LDB_ERR_OPERATIONS_ERROR;
		goto done;
	}

	ret = ldb_msg_add_steal_value(msg, attr_name, &v);
	if (ret != LDB_SUCCESS) {
		DEBUG(4,(__location__ ": Failed to add %s to the message\n",
					 attr_name));
		goto done;
	}

	ret = LDB_SUCCESS;

done:
	talloc_free(tmp_ctx);
	return ret;

}


/*
  use a DN to find a SID
 */
int dsdb_find_sid_by_dn(struct ldb_context *ldb, 
			struct ldb_dn *dn, struct dom_sid *sid)
{
	int ret;
	struct ldb_result *res;
	const char *attrs[] = { "objectSID", NULL };
	TALLOC_CTX *tmp_ctx = talloc_new(ldb);
	struct dom_sid *s;

	ZERO_STRUCTP(sid);

	ret = dsdb_search_dn_with_deleted(ldb, tmp_ctx, &res, dn, attrs);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}
	if (res->count < 1) {
		talloc_free(tmp_ctx);
		return LDB_ERR_NO_SUCH_OBJECT;
	}
	s = samdb_result_dom_sid(tmp_ctx, res->msgs[0], "objectSID");
	if (s == NULL) {
		talloc_free(tmp_ctx);
		return LDB_ERR_NO_SUCH_OBJECT;
	}
	*sid = *s;
	talloc_free(tmp_ctx);
	return LDB_SUCCESS;
}



/*
  load a repsFromTo blob list for a given partition GUID
  attr must be "repsFrom" or "repsTo"
 */
WERROR dsdb_loadreps(struct ldb_context *sam_ctx, TALLOC_CTX *mem_ctx, struct ldb_dn *dn,
		     const char *attr, struct repsFromToBlob **r, uint32_t *count)
{
	const char *attrs[] = { attr, NULL };
	struct ldb_result *res = NULL;
	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
	int i;
	struct ldb_message_element *el;

	*r = NULL;
	*count = 0;

	if (ldb_search(sam_ctx, tmp_ctx, &res, dn, LDB_SCOPE_BASE, attrs, NULL) != LDB_SUCCESS ||
	    res->count < 1) {
		DEBUG(0,("dsdb_loadreps: failed to read partition object\n"));
		talloc_free(tmp_ctx);
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	el = ldb_msg_find_element(res->msgs[0], attr);
	if (el == NULL) {
		/* it's OK to be empty */
		talloc_free(tmp_ctx);
		return WERR_OK;
	}

	*count = el->num_values;
	*r = talloc_array(mem_ctx, struct repsFromToBlob, *count);
	if (*r == NULL) {
		talloc_free(tmp_ctx);
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	for (i=0; i<(*count); i++) {
		enum ndr_err_code ndr_err;
		ndr_err = ndr_pull_struct_blob(&el->values[i], 
					       mem_ctx, lp_iconv_convenience(ldb_get_opaque(sam_ctx, "loadparm")),
					       &(*r)[i], 
					       (ndr_pull_flags_fn_t)ndr_pull_repsFromToBlob);
		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
			talloc_free(tmp_ctx);
			return WERR_DS_DRA_INTERNAL_ERROR;
		}
	}

	talloc_free(tmp_ctx);
	
	return WERR_OK;
}

/*
  save the repsFromTo blob list for a given partition GUID
  attr must be "repsFrom" or "repsTo"
 */
WERROR dsdb_savereps(struct ldb_context *sam_ctx, TALLOC_CTX *mem_ctx, struct ldb_dn *dn,
		     const char *attr, struct repsFromToBlob *r, uint32_t count)
{
	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
	struct ldb_message *msg;
	struct ldb_message_element *el;
	int i;

	msg = ldb_msg_new(tmp_ctx);
	msg->dn = dn;
	if (ldb_msg_add_empty(msg, attr, LDB_FLAG_MOD_REPLACE, &el) != LDB_SUCCESS) {
		goto failed;
	}

	el->values = talloc_array(msg, struct ldb_val, count);
	if (!el->values) {
		goto failed;
	}

	for (i=0; i<count; i++) {
		struct ldb_val v;
		enum ndr_err_code ndr_err;

		ndr_err = ndr_push_struct_blob(&v, tmp_ctx, lp_iconv_convenience(ldb_get_opaque(sam_ctx, "loadparm")),
					       &r[i], 
					       (ndr_push_flags_fn_t)ndr_push_repsFromToBlob);
		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
			goto failed;
		}

		el->num_values++;
		el->values[i] = v;
	}

	if (ldb_modify(sam_ctx, msg) != LDB_SUCCESS) {
		DEBUG(0,("Failed to store %s - %s\n", attr, ldb_errstring(sam_ctx)));
		goto failed;
	}

	talloc_free(tmp_ctx);
	
	return WERR_OK;

failed:
	talloc_free(tmp_ctx);
	return WERR_DS_DRA_INTERNAL_ERROR;
}


/*
  load the uSNHighest attribute from the @REPLCHANGED object for a
  partition
 */
int dsdb_load_partition_usn(struct ldb_context *ldb, struct ldb_dn *dn, uint64_t *uSN)
{
	struct ldb_request *req;
	int ret;
	TALLOC_CTX *tmp_ctx = talloc_new(ldb);
	struct dsdb_control_current_partition *p_ctrl;
	struct ldb_result *res;

	res = talloc_zero(tmp_ctx, struct ldb_result);
	if (!res) {
		talloc_free(tmp_ctx);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ldb_build_search_req(&req, ldb, tmp_ctx,
				   ldb_dn_new(tmp_ctx, ldb, "@REPLCHANGED"),
				   LDB_SCOPE_BASE,
				   NULL, NULL,
				   NULL,
				   res, ldb_search_default_callback,
				   NULL);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}

	p_ctrl = talloc(req, struct dsdb_control_current_partition);
	if (p_ctrl == NULL) {
		talloc_free(res);
		return LDB_ERR_OPERATIONS_ERROR;
	}
	p_ctrl->version = DSDB_CONTROL_CURRENT_PARTITION_VERSION;
	p_ctrl->dn = dn;
	

	ret = ldb_request_add_control(req,
				      DSDB_CONTROL_CURRENT_PARTITION_OID,
				      false, p_ctrl);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}
	
	/* Run the new request */
	ret = ldb_request(ldb, req);
	
	if (ret == LDB_SUCCESS) {
		ret = ldb_wait(req->handle, LDB_WAIT_ALL);
	}

	if (ret == LDB_ERR_NO_SUCH_OBJECT) {
		/* it hasn't been created yet, which means
		   an implicit value of zero */
		*uSN = 0;
		talloc_free(tmp_ctx);
		return LDB_SUCCESS;
	}

	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}

	if (res->count < 1) {
		*uSN = 0;
	} else {
		*uSN = ldb_msg_find_attr_as_uint64(res->msgs[0], "uSNHighest", 0);
	}

	talloc_free(tmp_ctx);

	return LDB_SUCCESS;	
}

/*
  save the uSNHighest attribute in the @REPLCHANGED object for a
  partition
 */
int dsdb_save_partition_usn(struct ldb_context *ldb, struct ldb_dn *dn, uint64_t uSN)
{
	struct ldb_request *req;
	struct ldb_message *msg;
	struct dsdb_control_current_partition *p_ctrl;
	int ret;

	msg = ldb_msg_new(ldb);
	if (msg == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	msg->dn = ldb_dn_new(msg, ldb, "@REPLCHANGED");
	if (msg->dn == NULL) {
		talloc_free(msg);
		return LDB_ERR_OPERATIONS_ERROR;
	}
	
	ret = ldb_msg_add_fmt(msg, "uSNHighest", "%llu", (unsigned long long)uSN);
	if (ret != LDB_SUCCESS) {
		talloc_free(msg);
		return ret;
	}
	msg->elements[0].flags = LDB_FLAG_MOD_REPLACE;
	

	p_ctrl = talloc(msg, struct dsdb_control_current_partition);
	if (p_ctrl == NULL) {
		talloc_free(msg);
		return LDB_ERR_OPERATIONS_ERROR;
	}
	p_ctrl->version = DSDB_CONTROL_CURRENT_PARTITION_VERSION;
	p_ctrl->dn = dn;

	ret = ldb_build_mod_req(&req, ldb, msg,
				msg,
				NULL,
				NULL, ldb_op_default_callback,
				NULL);
again:
	if (ret != LDB_SUCCESS) {
		talloc_free(msg);
		return ret;
	}
	
	ret = ldb_request_add_control(req,
				      DSDB_CONTROL_CURRENT_PARTITION_OID,
				      false, p_ctrl);
	if (ret != LDB_SUCCESS) {
		talloc_free(msg);
		return ret;
	}
	
	/* Run the new request */
	ret = ldb_request(ldb, req);
	
	if (ret == LDB_SUCCESS) {
		ret = ldb_wait(req->handle, LDB_WAIT_ALL);
	}
	if (ret == LDB_ERR_NO_SUCH_OBJECT) {
		ret = ldb_build_add_req(&req, ldb, msg,
					msg,
					NULL,
					NULL, ldb_op_default_callback,
					NULL);
		goto again;
	}
	
	talloc_free(msg);
	
	return ret;
}

int drsuapi_DsReplicaCursor2_compare(const struct drsuapi_DsReplicaCursor2 *c1,
						   const struct drsuapi_DsReplicaCursor2 *c2)
{
	return GUID_compare(&c1->source_dsa_invocation_id, &c2->source_dsa_invocation_id);
}

/*
  see if we are a RODC

  TODO: This should take a sam_ctx, and lookup the right object (with
  a cache)
*/
bool samdb_rodc(struct loadparm_context *lp_ctx)
{
	return lp_parm_bool(lp_ctx, NULL, "repl", "RODC", false);
}


/*
  return NTDS options flags. See MS-ADTS 7.1.1.2.2.1.2.1.1 

  flags are DS_NTDS_OPTION_*
*/
int samdb_ntds_options(struct ldb_context *ldb, uint32_t *options)
{
	TALLOC_CTX *tmp_ctx;
	const char *attrs[] = { "options", NULL };
	int ret;
	struct ldb_result *res;

	tmp_ctx = talloc_new(ldb);
	if (tmp_ctx == NULL) {
		goto failed;
	}

	ret = ldb_search(ldb, tmp_ctx, &res, samdb_ntds_settings_dn(ldb), LDB_SCOPE_BASE, attrs, NULL);
	if (ret) {
		goto failed;
	}

	if (res->count != 1) {
		goto failed;
	}

	*options = samdb_result_uint(res->msgs[0], "options", 0);

	talloc_free(tmp_ctx);

	return LDB_SUCCESS;

failed:
	DEBUG(1,("Failed to find our own NTDS Settings objectGUID in the ldb!\n"));
	talloc_free(tmp_ctx);
	return LDB_ERR_NO_SUCH_OBJECT;
}

/*
 * Function which generates a "lDAPDisplayName" attribute from a "CN" one.
 * Algorithm implemented according to MS-ADTS 3.1.1.2.3.4
 */
const char *samdb_cn_to_lDAPDisplayName(TALLOC_CTX *mem_ctx, const char *cn)
{
	char **tokens, *ret;
	size_t i;

	tokens = str_list_make(mem_ctx, cn, " -_");
	if (tokens == NULL)
		return NULL;

	/* "tolower()" and "toupper()" should also work properly on 0x00 */
	tokens[0][0] = tolower(tokens[0][0]);
	for (i = 1; i < str_list_length((const char **)tokens); i++)
		tokens[i][0] = toupper(tokens[i][0]);

	ret = talloc_strdup(mem_ctx, tokens[0]);
	for (i = 1; i < str_list_length((const char **)tokens); i++)
		ret = talloc_asprintf_append_buffer(ret, "%s", tokens[i]);

	talloc_free(tokens);

	return ret;
}

/*
  return domain functional level
  returns DS_DOMAIN_FUNCTION_*
 */
int dsdb_functional_level(struct ldb_context *ldb)
{
	int *domainFunctionality =
		talloc_get_type(ldb_get_opaque(ldb, "domainFunctionality"), int);
	if (!domainFunctionality) {
		DEBUG(0,(__location__ ": WARNING: domainFunctionality not setup\n"));
		return DS_DOMAIN_FUNCTION_2000;
	}
	return *domainFunctionality;
}

/*
  return a GUID from a extended DN structure
 */
NTSTATUS dsdb_get_extended_dn_guid(struct ldb_dn *dn, struct GUID *guid)
{
	const struct ldb_val *v;

	v = ldb_dn_get_extended_component(dn, "GUID");
	if (v == NULL) {
		return NT_STATUS_OBJECT_NAME_NOT_FOUND;
	}

	return GUID_from_ndr_blob(v, guid);
}

/*
  return a uint64_t from a extended DN structure
 */
NTSTATUS dsdb_get_extended_dn_uint64(struct ldb_dn *dn, uint64_t *val, const char *component_name)
{
	const struct ldb_val *v;
	char *s;

	v = ldb_dn_get_extended_component(dn, component_name);
	if (v == NULL) {
		return NT_STATUS_OBJECT_NAME_NOT_FOUND;
	}
	s = talloc_strndup(dn, (const char *)v->data, v->length);
	NT_STATUS_HAVE_NO_MEMORY(s);

	*val = strtoull(s, NULL, 0);

	talloc_free(s);
	return NT_STATUS_OK;
}

/*
  return a NTTIME from a extended DN structure
 */
NTSTATUS dsdb_get_extended_dn_nttime(struct ldb_dn *dn, NTTIME *nttime, const char *component_name)
{
	return dsdb_get_extended_dn_uint64(dn, nttime, component_name);
}

/*
  return a uint32_t from a extended DN structure
 */
NTSTATUS dsdb_get_extended_dn_uint32(struct ldb_dn *dn, uint32_t *val, const char *component_name)
{
	const struct ldb_val *v;
	char *s;

	v = ldb_dn_get_extended_component(dn, component_name);
	if (v == NULL) {
		return NT_STATUS_OBJECT_NAME_NOT_FOUND;
	}

	s = talloc_strndup(dn, (const char *)v->data, v->length);
	NT_STATUS_HAVE_NO_MEMORY(s);

	*val = strtoul(s, NULL, 0);

	talloc_free(s);
	return NT_STATUS_OK;
}

/*
  return true if a ldb_val containing a DN in storage form is deleted
 */
bool dsdb_dn_is_deleted_val(struct ldb_val *val)
{
	/* this relies on the sort order and exact format of
	   linearized extended DNs */
	if (val->length >= 12 &&
	    strncmp((const char *)val->data, "<DELETED=1>;", 12) == 0) {
		return true;
	}
	return false;
}

/*
  return a DN for a wellknown GUID
 */
int dsdb_wellknown_dn(struct ldb_context *samdb, TALLOC_CTX *mem_ctx,
		      struct ldb_dn *nc_root, const char *wk_guid,
		      struct ldb_dn **wkguid_dn)
{
	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
	const char *attrs[] = { NULL };
	int ret;
	struct ldb_dn *dn;
	struct ldb_result *res;

	/* construct the magic WKGUID DN */
	dn = ldb_dn_new_fmt(tmp_ctx, samdb, "<WKGUID=%s,%s>",
			    wk_guid, ldb_dn_get_linearized(nc_root));
	if (!wkguid_dn) {
		talloc_free(tmp_ctx);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = dsdb_search_dn_with_deleted(samdb, tmp_ctx, &res, dn, attrs);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}

	(*wkguid_dn) = talloc_steal(mem_ctx, res->msgs[0]->dn);
	talloc_free(tmp_ctx);
	return LDB_SUCCESS;
}


static int dsdb_dn_compare_ptrs(struct ldb_dn **dn1, struct ldb_dn **dn2)
{
	return ldb_dn_compare(*dn1, *dn2);
}

/*
  find a NC root given a DN within the NC
 */
int dsdb_find_nc_root(struct ldb_context *samdb, TALLOC_CTX *mem_ctx, struct ldb_dn *dn,
		      struct ldb_dn **nc_root)
{
	const char *root_attrs[] = { "namingContexts", NULL };
	TALLOC_CTX *tmp_ctx;
	int ret;
	struct ldb_message_element *el;
	struct ldb_result *root_res;
	int i;
	struct ldb_dn **nc_dns;

	tmp_ctx = talloc_new(samdb);
	if (tmp_ctx == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ldb_search(samdb, tmp_ctx, &root_res,
			 ldb_dn_new(tmp_ctx, samdb, ""), LDB_SCOPE_BASE, root_attrs, NULL);
	if (ret) {
		DEBUG(1,("Searching for namingContexts in rootDSE failed: %s\n", ldb_errstring(samdb)));
		talloc_free(tmp_ctx);
		return ret;
       }

       el = ldb_msg_find_element(root_res->msgs[0], "namingContexts");
       if (!el) {
               DEBUG(1,("Finding namingContexts element in root_res failed: %s\n",
			ldb_errstring(samdb)));
	       talloc_free(tmp_ctx);
	       return LDB_ERR_NO_SUCH_ATTRIBUTE;
       }

       nc_dns = talloc_array(tmp_ctx, struct ldb_dn *, el->num_values);
       if (!nc_dns) {
	       talloc_free(tmp_ctx);
	       return LDB_ERR_OPERATIONS_ERROR;
       }

       for (i=0; i<el->num_values; i++) {
	       nc_dns[i] = ldb_dn_from_ldb_val(nc_dns, samdb, &el->values[i]);
	       if (nc_dns[i] == NULL) {
		       talloc_free(tmp_ctx);
		       return LDB_ERR_OPERATIONS_ERROR;
	       }
       }

       qsort(nc_dns, el->num_values, sizeof(nc_dns[0]), (comparison_fn_t)dsdb_dn_compare_ptrs);

       for (i=0; i<el->num_values; i++) {
               if (ldb_dn_compare_base(nc_dns[i], dn) == 0) {
		       (*nc_root) = talloc_steal(mem_ctx, nc_dns[i]);
                       talloc_free(tmp_ctx);
                       return LDB_SUCCESS;
               }
       }

       talloc_free(tmp_ctx);
       return LDB_ERR_NO_SUCH_OBJECT;
}


/*
  find the deleted objects DN for any object, by looking for the NC
  root, then looking up the wellknown GUID
 */
int dsdb_get_deleted_objects_dn(struct ldb_context *ldb,
				TALLOC_CTX *mem_ctx, struct ldb_dn *obj_dn,
				struct ldb_dn **do_dn)
{
	struct ldb_dn *nc_root;
	int ret;

	ret = dsdb_find_nc_root(ldb, mem_ctx, obj_dn, &nc_root);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	ret = dsdb_wellknown_dn(ldb, mem_ctx, nc_root, DS_GUID_DELETED_OBJECTS_CONTAINER, do_dn);
	talloc_free(nc_root);
	return ret;
}