s4:dsdb Add extensive tests for the behaviour of dsdb_dn

[Samba/cd1.git] / source4 / dsdb / common / util.c

/* 
   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"

/*
  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,
                       TALLOC_CTX *mem_ctx,
                       struct ldb_dn *basedn,
                       const char *format, ...) _PRINTF_ATTRIBUTE(4,5)
{
        va_list ap;
        struct ldb_message **res;
        const char * const attrs[] = { NULL };
        int ret;

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

        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;
        enum ndr_err_code ndr_err;
        struct GUID guid;
        TALLOC_CTX *mem_ctx;

        ZERO_STRUCT(guid);

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

        mem_ctx = talloc_named_const(NULL, 0, "samdb_result_guid");
        if (!mem_ctx) return guid;
        ndr_err = ndr_pull_struct_blob(v, mem_ctx, NULL, &guid,
                                       (ndr_pull_flags_fn_t)ndr_pull_GUID);
        talloc_free(mem_ctx);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                return guid;
        }

        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(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(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(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(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);
}

/*
  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_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 delete the old one
                 * and set what we have of the hashes */
                CHECK_RET(samdb_msg_add_delete(ctx, mem_ctx, mod, "clearTextPassword"));

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

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

        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);
                return NT_STATUS_NO_MEMORY;
        }

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

        nt_status = samdb_set_password(ldb, mem_ctx,
                                       user_dn, NULL,
                                       msg, new_password,
                                       lmNewHash, ntNewHash,
                                       user_change, /* This is a password set, not change */
                                       reject_reason, _dominfo);
        if (!NT_STATUS_IS_OK(nt_status)) {
                ldb_transaction_cancel(ldb);
                return nt_status;
        }

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

        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(msg->dn),
                         ldb_errstring(ldb)));
                return NT_STATUS_TRANSACTION_ABORTED;
        }
        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;
}

/*
  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;
}