s3:registry: fix regdb_key_exists: the record has to contain at least the 4-byte...

[Samba.git] / source3 / registry / reg_backend_db.c

/* 
 *  Unix SMB/CIFS implementation.
 *  Virtual Windows Registry Layer
 *  Copyright (C) Gerald Carter                     2002-2005
 *  Copyright (C) Michael Adam                      2007-2011
 *  Copyright (C) Gregor Beck                       2011
 *
 *  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/>.
 */

/* Implementation of internal registry database functions. */

#include "includes.h"
#include "system/filesys.h"
#include "registry.h"
#include "reg_db.h"
#include "reg_util_internal.h"
#include "reg_backend_db.h"
#include "reg_objects.h"
#include "nt_printing.h"
#include "util_tdb.h"
#include "dbwrap/dbwrap.h"
#include "dbwrap/dbwrap_open.h"
#include "../libcli/security/secdesc.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_REGISTRY

static struct db_context *regdb = NULL;
static int regdb_refcount;

static bool regdb_key_exists(struct db_context *db, const char *key);
static WERROR regdb_fetch_keys_internal(struct db_context *db, const char *key,
                                        struct regsubkey_ctr *ctr);
static bool regdb_store_keys_internal(struct db_context *db, const char *key,
                                      struct regsubkey_ctr *ctr);
static int regdb_fetch_values_internal(struct db_context *db, const char* key,
                                       struct regval_ctr *values);
static bool regdb_store_values_internal(struct db_context *db, const char *key,
                                        struct regval_ctr *values);
static WERROR regdb_store_subkey_list(struct db_context *db, const char *parent,
                                      const char *key);

static WERROR regdb_create_basekey(struct db_context *db, const char *key);
static WERROR regdb_create_subkey_internal(struct db_context *db,
                                           const char *key,
                                           const char *subkey);

/* List the deepest path into the registry.  All part components will be created.*/

/* If you want to have a part of the path controlled by the tdb and part by
   a virtual registry db (e.g. printing), then you have to list the deepest path.
   For example,"HKLM/SOFTWARE/Microsoft/Windows NT/CurrentVersion/Print" 
   allows the reg_db backend to handle everything up to 
   "HKLM/SOFTWARE/Microsoft/Windows NT/CurrentVersion" and then we'll hook 
   the reg_printing backend onto the last component of the path (see 
   KEY_PRINTING_2K in include/rpc_reg.h)   --jerry */

static const char *builtin_registry_paths[] = {
        KEY_PRINTING_2K,
        KEY_PRINTING_PORTS,
        KEY_PRINTING,
        KEY_PRINTING "\\Forms",
        KEY_PRINTING "\\Printers",
        KEY_PRINTING "\\Environments\\Windows NT x86\\Print Processors\\winprint",
        KEY_SHARES,
        KEY_EVENTLOG,
        KEY_SMBCONF,
        KEY_PERFLIB,
        KEY_PERFLIB_009,
        KEY_GROUP_POLICY,
        KEY_SAMBA_GROUP_POLICY,
        KEY_GP_MACHINE_POLICY,
        KEY_GP_MACHINE_WIN_POLICY,
        KEY_HKCU,
        KEY_GP_USER_POLICY,
        KEY_GP_USER_WIN_POLICY,
        "HKLM\\Software\\Microsoft\\Windows NT\\CurrentVersion\\Winlogon\\GPExtensions",
        "HKLM\\SYSTEM\\CurrentControlSet\\Control\\Print\\Monitors",
        KEY_PROD_OPTIONS,
        "HKLM\\SYSTEM\\CurrentControlSet\\Control\\Terminal Server\\DefaultUserConfiguration",
        KEY_TCPIP_PARAMS,
        KEY_NETLOGON_PARAMS,
        KEY_HKU,
        KEY_HKCR,
        KEY_HKPD,
        KEY_HKPT,
         NULL };

struct builtin_regkey_value {
        const char *path;
        const char *valuename;
        uint32 type;
        union {
                const char *string;
                uint32 dw_value;
        } data;
};

static struct builtin_regkey_value builtin_registry_values[] = {
        { KEY_PRINTING_PORTS,
                SAMBA_PRINTER_PORT_NAME, REG_SZ, { "" } },
        { KEY_PRINTING_2K,
                "DefaultSpoolDirectory", REG_SZ, { "C:\\Windows\\System32\\Spool\\Printers" } },
        { KEY_EVENTLOG,
                "DisplayName", REG_SZ, { "Event Log" } },
        { KEY_EVENTLOG,
                "ErrorControl", REG_DWORD, { (char*)0x00000001 } },
        { NULL, NULL, 0, { NULL } }
};

static WERROR create_key_recursive(struct db_context *db,
                                   char *path,
                                   const char *subkey)
{
        WERROR werr;
        char *p;

        if (subkey == NULL) {
                return WERR_INVALID_PARAM;
        }

        if (path == NULL) {
                return regdb_create_basekey(db, subkey);
        }

        p = strrchr_m(path, '\\');

        if (p == NULL) {
                werr = create_key_recursive(db, NULL, path);
        } else {
                *p = '\0';
                werr = create_key_recursive(db, path, p+1);
                *p = '\\';
        }

        if (!W_ERROR_IS_OK(werr)) {
                goto done;
        }

        werr = regdb_create_subkey_internal(db, path, subkey);

done:
        return werr;
}

/**
 * Initialize a key in the registry:
 * create each component key of the specified path.
 */
static WERROR init_registry_key_internal(struct db_context *db,
                                         const char *add_path)
{
        char *subkey, *key;
        WERROR werr;
        TALLOC_CTX *frame = talloc_stackframe();

        if (add_path == NULL) {
                werr = WERR_INVALID_PARAM;
                goto done;
        }

        key = talloc_strdup(frame, add_path);

        subkey = strrchr_m(key, '\\');
        if (subkey == NULL) {
                subkey = key;
                key = NULL;
        } else {
                *subkey = '\0';
                subkey++;
        }

        werr = create_key_recursive(db, key, subkey);

done:
        talloc_free(frame);
        return werr;
}

struct init_registry_key_context {
        const char *add_path;
};

static NTSTATUS init_registry_key_action(struct db_context *db,
                                         void *private_data)
{
        struct init_registry_key_context *init_ctx =
                (struct init_registry_key_context *)private_data;

        return werror_to_ntstatus(init_registry_key_internal(
                                        db, init_ctx->add_path));
}

/**
 * Initialize a key in the registry:
 * create each component key of the specified path,
 * wrapped in one db transaction.
 */
WERROR init_registry_key(const char *add_path)
{
        struct init_registry_key_context init_ctx;

        if (regdb_key_exists(regdb, add_path)) {
                return WERR_OK;
        }

        init_ctx.add_path = add_path;

        return ntstatus_to_werror(dbwrap_trans_do(regdb,
                                                  init_registry_key_action,
                                                  &init_ctx));
}

/***********************************************************************
 Open the registry data in the tdb
 ***********************************************************************/

static void regdb_ctr_add_value(struct regval_ctr *ctr,
                                struct builtin_regkey_value *value)
{
        switch(value->type) {
        case REG_DWORD:
                regval_ctr_addvalue(ctr, value->valuename, REG_DWORD,
                                    (uint8_t *)&value->data.dw_value,
                                    sizeof(uint32));
                break;

        case REG_SZ:
                regval_ctr_addvalue_sz(ctr, value->valuename,
                                       value->data.string);
                break;

        default:
                DEBUG(0, ("regdb_ctr_add_value: invalid value type in "
                          "registry values [%d]\n", value->type));
        }
}

static NTSTATUS init_registry_data_action(struct db_context *db,
                                          void *private_data)
{
        NTSTATUS status;
        TALLOC_CTX *frame = talloc_stackframe();
        struct regval_ctr *values;
        int i;

        /* loop over all of the predefined paths and add each component */

        for (i=0; builtin_registry_paths[i] != NULL; i++) {
                if (regdb_key_exists(db, builtin_registry_paths[i])) {
                        continue;
                }
                status = werror_to_ntstatus(init_registry_key_internal(db,
                                                  builtin_registry_paths[i]));
                if (!NT_STATUS_IS_OK(status)) {
                        goto done;
                }
        }

        /* loop over all of the predefined values and add each component */

        for (i=0; builtin_registry_values[i].path != NULL; i++) {
                WERROR werr;

                werr = regval_ctr_init(frame, &values);
                if (!W_ERROR_IS_OK(werr)) {
                        status = werror_to_ntstatus(werr);
                        goto done;
                }

                regdb_fetch_values_internal(db,
                                            builtin_registry_values[i].path,
                                            values);

                /* preserve existing values across restarts. Only add new ones */

                if (!regval_ctr_key_exists(values,
                                        builtin_registry_values[i].valuename))
                {
                        regdb_ctr_add_value(values,
                                            &builtin_registry_values[i]);
                        regdb_store_values_internal(db,
                                        builtin_registry_values[i].path,
                                        values);
                }
                TALLOC_FREE(values);
        }

        status = NT_STATUS_OK;

done:

        TALLOC_FREE(frame);
        return status;
}

WERROR init_registry_data(void)
{
        WERROR werr;
        TALLOC_CTX *frame = talloc_stackframe();
        struct regval_ctr *values;
        int i;

        /*
         * First, check for the existence of the needed keys and values.
         * If all do already exist, we can save the writes.
         */
        for (i=0; builtin_registry_paths[i] != NULL; i++) {
                if (!regdb_key_exists(regdb, builtin_registry_paths[i])) {
                        goto do_init;
                }
        }

        for (i=0; builtin_registry_values[i].path != NULL; i++) {
                werr = regval_ctr_init(frame, &values);
                W_ERROR_NOT_OK_GOTO_DONE(werr);

                regdb_fetch_values_internal(regdb,
                                            builtin_registry_values[i].path,
                                            values);
                if (!regval_ctr_key_exists(values,
                                        builtin_registry_values[i].valuename))
                {
                        TALLOC_FREE(values);
                        goto do_init;
                }

                TALLOC_FREE(values);
        }

        werr = WERR_OK;
        goto done;

do_init:

        /*
         * There are potentially quite a few store operations which are all
         * indiviually wrapped in tdb transactions. Wrapping them in a single
         * transaction gives just a single transaction_commit() to actually do
         * its fsync()s. See tdb/common/transaction.c for info about nested
         * transaction behaviour.
         */

        werr = ntstatus_to_werror(dbwrap_trans_do(regdb,
                                                  init_registry_data_action,
                                                  NULL));

done:
        TALLOC_FREE(frame);
        return werr;
}

static int regdb_normalize_keynames_fn(struct db_record *rec,
                                       void *private_data)
{
        TALLOC_CTX *mem_ctx = talloc_tos();
        const char *keyname;
        NTSTATUS status;

        if (rec->key.dptr == NULL || rec->key.dsize == 0) {
                return 0;
        }

        keyname = strchr((const char *) rec->key.dptr, '/');
        if (keyname) {
                struct db_record new_rec;

                keyname = talloc_string_sub(mem_ctx,
                                            (const char *) rec->key.dptr,
                                            "/",
                                            "\\");

                DEBUG(2, ("regdb_normalize_keynames_fn: Convert %s to %s\n",
                          (const char *) rec->key.dptr,
                          keyname));

                new_rec.value = rec->value;
                new_rec.key = string_term_tdb_data(keyname);
                new_rec.private_data = rec->private_data;

                /* Delete the original record and store the normalized key */
                status = rec->delete_rec(rec);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(0,("regdb_normalize_keynames_fn: "
                                 "tdb_delete for [%s] failed!\n",
                                 rec->key.dptr));
                        return 1;
                }

                status = rec->store(&new_rec, new_rec.value, TDB_REPLACE);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(0,("regdb_normalize_keynames_fn: "
                                 "failed to store new record for [%s]!\n",
                                 keyname));
                        return 1;
                }
        }

        return 0;
}

static WERROR regdb_store_regdb_version(struct db_context *db, uint32_t version)
{
        NTSTATUS status;
        const char *version_keyname = "INFO/version";

        if (db == NULL) {
                return WERR_CAN_NOT_COMPLETE;
        }

        status = dbwrap_trans_store_int32(db, version_keyname, version);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(1, ("regdb_store_regdb_version: error storing %s = %d: %s\n",
                          version_keyname, version, nt_errstr(status)));
                return ntstatus_to_werror(status);
        } else {
                DEBUG(10, ("regdb_store_regdb_version: stored %s = %d\n",
                          version_keyname, version));
                return WERR_OK;
        }
}

static WERROR regdb_upgrade_v1_to_v2(struct db_context *db)
{
        TALLOC_CTX *mem_ctx;
        int rc;
        WERROR werr;

        mem_ctx = talloc_stackframe();

        rc = regdb->traverse(db, regdb_normalize_keynames_fn, mem_ctx);

        talloc_free(mem_ctx);

        if (rc < 0) {
                return WERR_REG_IO_FAILURE;
        }

        werr = regdb_store_regdb_version(db, REGVER_V2);
        return werr;
}

static int regdb_upgrade_v2_to_v3_fn(struct db_record *rec, void *private_data)
{
        const char *keyname;
        fstring subkeyname;
        NTSTATUS status;
        WERROR werr;
        uint8_t *buf;
        uint32_t buflen, len;
        uint32_t num_items;
        uint32_t i;

        if (rec->key.dptr == NULL || rec->key.dsize == 0) {
                return 0;
        }

        keyname = (const char *)rec->key.dptr;

        if (strncmp(keyname, REG_SORTED_SUBKEYS_PREFIX,
                    strlen(REG_SORTED_SUBKEYS_PREFIX)) == 0)
        {
                /* Delete the deprecated sorted subkeys cache. */

                DEBUG(10, ("regdb_upgrade_v2_to_v3: deleting [%s]\n", keyname));

                status = rec->delete_rec(rec);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(0, ("regdb_upgrade_v2_to_v3: tdb_delete for [%s] "
                                  "failed!\n", keyname));
                        return 1;
                }

                return 0;
        }

        if (strncmp(keyname, REG_VALUE_PREFIX, strlen(REG_VALUE_PREFIX)) == 0) {
                DEBUG(10, ("regdb_upgrade_v2_to_v3: skipping [%s]\n", keyname));
                return 0;
        }

        if (strncmp(keyname, REG_SECDESC_PREFIX,
                    strlen(REG_SECDESC_PREFIX)) == 0)
        {
                DEBUG(10, ("regdb_upgrade_v2_to_v3: skipping [%s]\n", keyname));
                return 0;
        }

        /*
         * Found a regular subkey list record.
         * Walk the list and create the list record for those
         * subkeys that don't already have one.
         */
        DEBUG(10, ("regdb_upgrade_v2_to_v3: scanning subkey list of [%s]\n",
                   keyname));

        buf = rec->value.dptr;
        buflen = rec->value.dsize;

        len = tdb_unpack(buf, buflen, "d", &num_items);
        if (len == (uint32_t)-1) {
                /* invalid or empty - skip */
                return 0;
        }

        for (i=0; i<num_items; i++) {
                len += tdb_unpack(buf+len, buflen-len, "f", subkeyname);
                DEBUG(10, ("regdb_upgrade_v2_to_v3: "
                           "writing subkey list for [%s\\%s]\n",
                           keyname, subkeyname));
                werr = regdb_store_subkey_list(regdb, keyname, subkeyname);
                if (!W_ERROR_IS_OK(werr)) {
                        return 1;
                }
        }

        return 0;
}

static WERROR regdb_upgrade_v2_to_v3(struct db_context *db)
{
        int rc;
        WERROR werr;
        TALLOC_CTX *frame = talloc_stackframe();

        rc = regdb->traverse(db, regdb_upgrade_v2_to_v3_fn, frame);
        if (rc < 0) {
                werr = WERR_REG_IO_FAILURE;
                goto done;
        }

        werr = regdb_store_regdb_version(db, REGVER_V3);

done:
        talloc_free(frame);
        return werr;
}

/***********************************************************************
 Open the registry database
 ***********************************************************************/

WERROR regdb_init(void)
{
        const char *vstring = "INFO/version";
        uint32 vers_id, expected_version;
        WERROR werr;

        if (regdb) {
                DEBUG(10, ("regdb_init: incrementing refcount (%d->%d)\n",
                           regdb_refcount, regdb_refcount+1));
                regdb_refcount++;
                return WERR_OK;
        }

        regdb = db_open(NULL, state_path("registry.tdb"), 0,
                              REG_TDB_FLAGS, O_RDWR, 0600);
        if (!regdb) {
                regdb = db_open(NULL, state_path("registry.tdb"), 0,
                                      REG_TDB_FLAGS, O_RDWR|O_CREAT, 0600);
                if (!regdb) {
                        werr = ntstatus_to_werror(map_nt_error_from_unix(errno));
                        DEBUG(1,("regdb_init: Failed to open registry %s (%s)\n",
                                state_path("registry.tdb"), strerror(errno) ));
                        return werr;
                }

                DEBUG(10,("regdb_init: Successfully created registry tdb\n"));
        }

        regdb_refcount = 1;
        DEBUG(10, ("regdb_init: registry db openend. refcount reset (%d)\n",
                   regdb_refcount));

        expected_version = REGVER_V3;

        vers_id = dbwrap_fetch_int32(regdb, vstring);
        if (vers_id == -1) {
                DEBUG(10, ("regdb_init: registry version uninitialized "
                           "(got %d), initializing to version %d\n",
                           vers_id, expected_version));

                werr = regdb_store_regdb_version(regdb, expected_version);
                return werr;
        }

        if (vers_id > expected_version || vers_id == 0) {
                DEBUG(1, ("regdb_init: unknown registry version %d "
                          "(code version = %d), refusing initialization\n",
                          vers_id, expected_version));
                return WERR_CAN_NOT_COMPLETE;
        }

        if (regdb->transaction_start(regdb) != 0) {
                return WERR_REG_IO_FAILURE;
        }

        if (vers_id == REGVER_V1) {
                DEBUG(10, ("regdb_init: upgrading registry fromversion %d "
                           "to %d\n", REGVER_V1, REGVER_V2));

                werr = regdb_upgrade_v1_to_v2(regdb);
                if (!W_ERROR_IS_OK(werr)) {
                        regdb->transaction_cancel(regdb);
                        return werr;
                }

                vers_id = REGVER_V2;
        }

        if (vers_id == REGVER_V2) {
                DEBUG(10, ("regdb_init: upgrading registry from version %d "
                           "to %d\n", REGVER_V2, REGVER_V3));

                werr = regdb_upgrade_v2_to_v3(regdb);
                if (!W_ERROR_IS_OK(werr)) {
                        regdb->transaction_cancel(regdb);
                        return werr;
                }

                vers_id = REGVER_V3;
        }

        /* future upgrade code should go here */

        if (regdb->transaction_commit(regdb) != 0) {
                return WERR_REG_IO_FAILURE;
        }

        return WERR_OK;
}

/***********************************************************************
 Open the registry.  Must already have been initialized by regdb_init()
 ***********************************************************************/

WERROR regdb_open( void )
{
        WERROR result = WERR_OK;

        if ( regdb ) {
                DEBUG(10, ("regdb_open: incrementing refcount (%d->%d)\n",
                           regdb_refcount, regdb_refcount+1));
                regdb_refcount++;
                return WERR_OK;
        }

        become_root();

        regdb = db_open(NULL, state_path("registry.tdb"), 0,
                              REG_TDB_FLAGS, O_RDWR, 0600);
        if ( !regdb ) {
                result = ntstatus_to_werror( map_nt_error_from_unix( errno ) );
                DEBUG(0,("regdb_open: Failed to open %s! (%s)\n",
                        state_path("registry.tdb"), strerror(errno) ));
        }

        unbecome_root();

        regdb_refcount = 1;
        DEBUG(10, ("regdb_open: registry db opened. refcount reset (%d)\n",
                   regdb_refcount));

        return result;
}

/***********************************************************************
 ***********************************************************************/

int regdb_close( void )
{
        if (regdb_refcount == 0) {
                return 0;
        }

        regdb_refcount--;

        DEBUG(10, ("regdb_close: decrementing refcount (%d->%d)\n",
                   regdb_refcount+1, regdb_refcount));

        if ( regdb_refcount > 0 )
                return 0;

        SMB_ASSERT( regdb_refcount >= 0 );

        TALLOC_FREE(regdb);
        return 0;
}

WERROR regdb_transaction_start(void)
{
        return (regdb->transaction_start(regdb) == 0) ?
                WERR_OK : WERR_REG_IO_FAILURE;
}

WERROR regdb_transaction_commit(void)
{
        return (regdb->transaction_commit(regdb) == 0) ?
                WERR_OK : WERR_REG_IO_FAILURE;
}

WERROR regdb_transaction_cancel(void)
{
        return (regdb->transaction_cancel(regdb) == 0) ?
                WERR_OK : WERR_REG_IO_FAILURE;
}

/***********************************************************************
 return the tdb sequence number of the registry tdb.
 this is an indicator for the content of the registry
 having changed. it will change upon regdb_init, too, though.
 ***********************************************************************/
int regdb_get_seqnum(void)
{
        return regdb->get_seqnum(regdb);
}


static WERROR regdb_delete_key_with_prefix(struct db_context *db,
                                           const char *keyname,
                                           const char *prefix)
{
        char *path;
        WERROR werr = WERR_NOMEM;
        TALLOC_CTX *mem_ctx = talloc_stackframe();

        if (keyname == NULL) {
                werr = WERR_INVALID_PARAM;
                goto done;
        }

        if (prefix == NULL) {
                path = discard_const_p(char, keyname);
        } else {
                path = talloc_asprintf(mem_ctx, "%s\\%s", prefix, keyname);
                if (path == NULL) {
                        goto done;
                }
        }

        path = normalize_reg_path(mem_ctx, path);
        if (path == NULL) {
                goto done;
        }

        werr = ntstatus_to_werror(dbwrap_delete_bystring(db, path));

        /* treat "not found" as ok */
        if (W_ERROR_EQUAL(werr, WERR_NOT_FOUND)) {
                werr = WERR_OK;
        }

done:
        talloc_free(mem_ctx);
        return werr;
}


static WERROR regdb_delete_values(struct db_context *db, const char *keyname)
{
        return regdb_delete_key_with_prefix(db, keyname, REG_VALUE_PREFIX);
}

static WERROR regdb_delete_secdesc(struct db_context *db, const char *keyname)
{
        return regdb_delete_key_with_prefix(db, keyname, REG_SECDESC_PREFIX);
}

static WERROR regdb_delete_subkeylist(struct db_context *db, const char *keyname)
{
        return regdb_delete_key_with_prefix(db, keyname, NULL);
}


static WERROR regdb_delete_key_lists(struct db_context *db, const char *keyname)
{
        WERROR werr;

        werr = regdb_delete_values(db, keyname);
        if (!W_ERROR_IS_OK(werr)) {
                DEBUG(1, (__location__ " Deleting %s\\%s failed: %s\n",
                          REG_VALUE_PREFIX, keyname, win_errstr(werr)));
                goto done;
        }

        werr = regdb_delete_secdesc(db, keyname);
        if (!W_ERROR_IS_OK(werr)) {
                DEBUG(1, (__location__ " Deleting %s\\%s failed: %s\n",
                          REG_SECDESC_PREFIX, keyname, win_errstr(werr)));
                goto done;
        }

        werr = regdb_delete_subkeylist(db, keyname);
        if (!W_ERROR_IS_OK(werr)) {
                DEBUG(1, (__location__ " Deleting %s failed: %s\n",
                          keyname, win_errstr(werr)));
                goto done;
        }

done:
        return werr;
}

/***********************************************************************
 Add subkey strings to the registry tdb under a defined key
 fmt is the same format as tdb_pack except this function only supports
 fstrings
 ***********************************************************************/

static WERROR regdb_store_keys_internal2(struct db_context *db,
                                         const char *key,
                                         struct regsubkey_ctr *ctr)
{
        TDB_DATA dbuf;
        uint8 *buffer = NULL;
        int i = 0;
        uint32 len, buflen;
        uint32 num_subkeys = regsubkey_ctr_numkeys(ctr);
        char *keyname = NULL;
        TALLOC_CTX *ctx = talloc_stackframe();
        WERROR werr;

        if (!key) {
                werr = WERR_INVALID_PARAM;
                goto done;
        }

        keyname = talloc_strdup(ctx, key);
        if (!keyname) {
                werr = WERR_NOMEM;
                goto done;
        }

        keyname = normalize_reg_path(ctx, keyname);
        if (!keyname) {
                werr = WERR_NOMEM;
                goto done;
        }

        /* allocate some initial memory */

        buffer = (uint8 *)SMB_MALLOC(1024);
        if (buffer == NULL) {
                werr = WERR_NOMEM;
                goto done;
        }
        buflen = 1024;
        len = 0;

        /* store the number of subkeys */

        len += tdb_pack(buffer+len, buflen-len, "d", num_subkeys);

        /* pack all the strings */

        for (i=0; i<num_subkeys; i++) {
                size_t thistime;

                thistime = tdb_pack(buffer+len, buflen-len, "f",
                                    regsubkey_ctr_specific_key(ctr, i));
                if (len+thistime > buflen) {
                        size_t thistime2;
                        /*
                         * tdb_pack hasn't done anything because of the short
                         * buffer, allocate extra space.
                         */
                        buffer = SMB_REALLOC_ARRAY(buffer, uint8_t,
                                                   (len+thistime)*2);
                        if(buffer == NULL) {
                                DEBUG(0, ("regdb_store_keys: Failed to realloc "
                                          "memory of size [%u]\n",
                                          (unsigned int)(len+thistime)*2));
                                werr = WERR_NOMEM;
                                goto done;
                        }
                        buflen = (len+thistime)*2;
                        thistime2 = tdb_pack(
                                buffer+len, buflen-len, "f",
                                regsubkey_ctr_specific_key(ctr, i));
                        if (thistime2 != thistime) {
                                DEBUG(0, ("tdb_pack failed\n"));
                                werr = WERR_CAN_NOT_COMPLETE;
                                goto done;
                        }
                }
                len += thistime;
        }

        /* finally write out the data */

        dbuf.dptr = buffer;
        dbuf.dsize = len;
        werr = ntstatus_to_werror(dbwrap_store_bystring(db, keyname, dbuf,
                                                        TDB_REPLACE));

done:
        TALLOC_FREE(ctx);
        SAFE_FREE(buffer);
        return werr;
}

/**
 * Utility function to store a new empty list of
 * subkeys of given key specified as parent and subkey name
 * (thereby creating the key).
 * If the parent keyname is NULL, then the "subkey" is
 * interpreted as a base key.
 * If the subkey list does already exist, it is not modified.
 *
 * Must be called from within a transaction.
 */
static WERROR regdb_store_subkey_list(struct db_context *db, const char *parent,
                                      const char *key)
{
        WERROR werr;
        char *path = NULL;
        struct regsubkey_ctr *subkeys = NULL;
        TALLOC_CTX *frame = talloc_stackframe();

        if (parent == NULL) {
                path = talloc_strdup(frame, key);
        } else {
                path = talloc_asprintf(frame, "%s\\%s", parent, key);
        }
        if (!path) {
                werr = WERR_NOMEM;
                goto done;
        }

        werr = regsubkey_ctr_init(frame, &subkeys);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regdb_fetch_keys_internal(db, path, subkeys);
        if (W_ERROR_IS_OK(werr)) {
                /* subkey list exists already - don't modify */
                goto done;
        }

        werr = regsubkey_ctr_reinit(subkeys);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        /* create a record with 0 subkeys */
        werr = regdb_store_keys_internal2(db, path, subkeys);
        if (!W_ERROR_IS_OK(werr)) {
                DEBUG(0, ("regdb_store_keys: Failed to store new record for "
                          "key [%s]: %s\n", path, win_errstr(werr)));
                goto done;
        }

done:
        talloc_free(frame);
        return werr;
}

/***********************************************************************
 Store the new subkey record and create any child key records that
 do not currently exist
 ***********************************************************************/

struct regdb_store_keys_context {
        const char *key;
        struct regsubkey_ctr *ctr;
};

static NTSTATUS regdb_store_keys_action(struct db_context *db,
                                        void *private_data)
{
        struct regdb_store_keys_context *store_ctx;
        WERROR werr;
        int num_subkeys, i;
        char *path = NULL;
        struct regsubkey_ctr *old_subkeys = NULL;
        char *oldkeyname = NULL;
        TALLOC_CTX *mem_ctx = talloc_stackframe();

        store_ctx = (struct regdb_store_keys_context *)private_data;

        /*
         * Re-fetch the old keys inside the transaction
         */

        werr = regsubkey_ctr_init(mem_ctx, &old_subkeys);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regdb_fetch_keys_internal(db, store_ctx->key, old_subkeys);
        if (!W_ERROR_IS_OK(werr) &&
            !W_ERROR_EQUAL(werr, WERR_NOT_FOUND))
        {
                goto done;
        }

        /*
         * Make the store operation as safe as possible without transactions:
         *
         * (1) For each subkey removed from ctr compared with old_subkeys:
         *
         *     (a) First delete the value db entry.
         *
         *     (b) Next delete the secdesc db record.
         *
         *     (c) Then delete the subkey list entry.
         *
         * (2) Now write the list of subkeys of the parent key,
         *     deleting removed entries and adding new ones.
         *
         * (3) Finally create the subkey list entries for the added keys.
         *
         * This way if we crash half-way in between deleting the subkeys
         * and storing the parent's list of subkeys, no old data can pop up
         * out of the blue when re-adding keys later on.
         */

        /* (1) delete removed keys' lists (values/secdesc/subkeys) */

        num_subkeys = regsubkey_ctr_numkeys(old_subkeys);
        for (i=0; i<num_subkeys; i++) {
                oldkeyname = regsubkey_ctr_specific_key(old_subkeys, i);

                if (regsubkey_ctr_key_exists(store_ctx->ctr, oldkeyname)) {
                        /*
                         * It's still around, don't delete
                         */
                        continue;
                }

                path = talloc_asprintf(mem_ctx, "%s\\%s", store_ctx->key,
                                       oldkeyname);
                if (!path) {
                        werr = WERR_NOMEM;
                        goto done;
                }

                werr = regdb_delete_key_lists(db, path);
                W_ERROR_NOT_OK_GOTO_DONE(werr);

                TALLOC_FREE(path);
        }

        TALLOC_FREE(old_subkeys);

        /* (2) store the subkey list for the parent */

        werr = regdb_store_keys_internal2(db, store_ctx->key, store_ctx->ctr);
        if (!W_ERROR_IS_OK(werr)) {
                DEBUG(0,("regdb_store_keys: Failed to store new subkey list "
                         "for parent [%s]: %s\n", store_ctx->key,
                         win_errstr(werr)));
                goto done;
        }

        /* (3) now create records for any subkeys that don't already exist */

        num_subkeys = regsubkey_ctr_numkeys(store_ctx->ctr);

        for (i=0; i<num_subkeys; i++) {
                const char *subkey;

                subkey = regsubkey_ctr_specific_key(store_ctx->ctr, i);

                werr = regdb_store_subkey_list(db, store_ctx->key, subkey);
                W_ERROR_NOT_OK_GOTO_DONE(werr);
        }

        werr = WERR_OK;

done:
        talloc_free(mem_ctx);
        return werror_to_ntstatus(werr);
}

static bool regdb_store_keys_internal(struct db_context *db, const char *key,
                                      struct regsubkey_ctr *ctr)
{
        int num_subkeys, old_num_subkeys, i;
        struct regsubkey_ctr *old_subkeys = NULL;
        TALLOC_CTX *ctx = talloc_stackframe();
        WERROR werr;
        bool ret = false;
        struct regdb_store_keys_context store_ctx;

        if (!regdb_key_exists(db, key)) {
                goto done;
        }

        /*
         * fetch a list of the old subkeys so we can determine if anything has
         * changed
         */

        werr = regsubkey_ctr_init(ctx, &old_subkeys);
        if (!W_ERROR_IS_OK(werr)) {
                DEBUG(0,("regdb_store_keys: talloc() failure!\n"));
                goto done;
        }

        werr = regdb_fetch_keys_internal(db, key, old_subkeys);
        if (!W_ERROR_IS_OK(werr) &&
            !W_ERROR_EQUAL(werr, WERR_NOT_FOUND))
        {
                goto done;
        }

        num_subkeys = regsubkey_ctr_numkeys(ctr);
        old_num_subkeys = regsubkey_ctr_numkeys(old_subkeys);
        if ((num_subkeys && old_num_subkeys) &&
            (num_subkeys == old_num_subkeys)) {

                for (i = 0; i < num_subkeys; i++) {
                        if (strcmp(regsubkey_ctr_specific_key(ctr, i),
                                   regsubkey_ctr_specific_key(old_subkeys, i))
                            != 0)
                        {
                                break;
                        }
                }
                if (i == num_subkeys) {
                        /*
                         * Nothing changed, no point to even start a tdb
                         * transaction
                         */

                        ret = true;
                        goto done;
                }
        }

        TALLOC_FREE(old_subkeys);

        store_ctx.key = key;
        store_ctx.ctr = ctr;

        werr = ntstatus_to_werror(dbwrap_trans_do(db,
                                                  regdb_store_keys_action,
                                                  &store_ctx));

        ret = W_ERROR_IS_OK(werr);

done:
        TALLOC_FREE(ctx);

        return ret;
}

bool regdb_store_keys(const char *key, struct regsubkey_ctr *ctr)
{
        return regdb_store_keys_internal(regdb, key, ctr);
}

/**
 * create a subkey of a given key
 */

struct regdb_create_subkey_context {
        const char *key;
        const char *subkey;
};

static NTSTATUS regdb_create_subkey_action(struct db_context *db,
                                           void *private_data)
{
        WERROR werr;
        struct regdb_create_subkey_context *create_ctx;
        struct regsubkey_ctr *subkeys;
        TALLOC_CTX *mem_ctx = talloc_stackframe();

        create_ctx = (struct regdb_create_subkey_context *)private_data;

        werr = regsubkey_ctr_init(mem_ctx, &subkeys);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regdb_fetch_keys_internal(db, create_ctx->key, subkeys);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regsubkey_ctr_addkey(subkeys, create_ctx->subkey);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regdb_store_keys_internal2(db, create_ctx->key, subkeys);
        if (!W_ERROR_IS_OK(werr)) {
                DEBUG(0, (__location__ " failed to store new subkey list for "
                         "parent key %s: %s\n", create_ctx->key,
                         win_errstr(werr)));
        }

        werr = regdb_store_subkey_list(db, create_ctx->key, create_ctx->subkey);

done:
        talloc_free(mem_ctx);
        return werror_to_ntstatus(werr);
}

static WERROR regdb_create_subkey_internal(struct db_context *db,
                                           const char *key,
                                           const char *subkey)
{
        WERROR werr;
        struct regsubkey_ctr *subkeys;
        TALLOC_CTX *mem_ctx = talloc_stackframe();
        struct regdb_create_subkey_context create_ctx;

        if (!regdb_key_exists(db, key)) {
                werr = WERR_NOT_FOUND;
                goto done;
        }

        werr = regsubkey_ctr_init(mem_ctx, &subkeys);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regdb_fetch_keys_internal(db, key, subkeys);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        if (regsubkey_ctr_key_exists(subkeys, subkey)) {
                werr = WERR_OK;
                goto done;
        }

        talloc_free(subkeys);

        create_ctx.key = key;
        create_ctx.subkey = subkey;

        werr = ntstatus_to_werror(dbwrap_trans_do(db,
                                                  regdb_create_subkey_action,
                                                  &create_ctx));

done:
        talloc_free(mem_ctx);
        return werr;
}

static WERROR regdb_create_subkey(const char *key, const char *subkey)
{
        return regdb_create_subkey_internal(regdb, key, subkey);
}

/**
 * create a base key
 */

struct regdb_create_basekey_context {
        const char *key;
};

static NTSTATUS regdb_create_basekey_action(struct db_context *db,
                                            void *private_data)
{
        WERROR werr;
        struct regdb_create_basekey_context *create_ctx;

        create_ctx = (struct regdb_create_basekey_context *)private_data;

        werr = regdb_store_subkey_list(db, NULL, create_ctx->key);

        return werror_to_ntstatus(werr);
}

static WERROR regdb_create_basekey(struct db_context *db, const char *key)
{
        WERROR werr;
        struct regdb_create_subkey_context create_ctx;

        create_ctx.key = key;

        werr = ntstatus_to_werror(dbwrap_trans_do(db,
                                                  regdb_create_basekey_action,
                                                  &create_ctx));

        return werr;
}

/**
 * create a subkey of a given key
 */

struct regdb_delete_subkey_context {
        const char *key;
        const char *subkey;
        const char *path;
        bool lazy;
};

static NTSTATUS regdb_delete_subkey_action(struct db_context *db,
                                           void *private_data)
{
        WERROR werr;
        struct regdb_delete_subkey_context *delete_ctx;
        struct regsubkey_ctr *subkeys;
        TALLOC_CTX *mem_ctx = talloc_stackframe();

        delete_ctx = (struct regdb_delete_subkey_context *)private_data;

        werr = regdb_delete_key_lists(db, delete_ctx->path);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        if (delete_ctx->lazy) {
                goto done;
        }

        werr = regsubkey_ctr_init(mem_ctx, &subkeys);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regdb_fetch_keys_internal(db, delete_ctx->key, subkeys);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regsubkey_ctr_delkey(subkeys, delete_ctx->subkey);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regdb_store_keys_internal2(db, delete_ctx->key, subkeys);
        if (!W_ERROR_IS_OK(werr)) {
                DEBUG(0, (__location__ " failed to store new subkey_list for "
                         "parent key %s: %s\n", delete_ctx->key,
                         win_errstr(werr)));
        }

done:
        talloc_free(mem_ctx);
        return werror_to_ntstatus(werr);
}

static WERROR regdb_delete_subkey(const char *key, const char *subkey, bool lazy)
{
        WERROR werr;
        char *path;
        struct regdb_delete_subkey_context delete_ctx;
        TALLOC_CTX *mem_ctx = talloc_stackframe();

        if (!regdb_key_exists(regdb, key)) {
                werr = WERR_NOT_FOUND;
                goto done;
        }

        path = talloc_asprintf(mem_ctx, "%s\\%s", key, subkey);
        if (path == NULL) {
                werr = WERR_NOMEM;
                goto done;
        }

        if (!regdb_key_exists(regdb, path)) {
                werr = WERR_OK;
                goto done;
        }

        delete_ctx.key = key;
        delete_ctx.subkey = subkey;
        delete_ctx.path = path;
        delete_ctx.lazy = lazy;

        werr = ntstatus_to_werror(dbwrap_trans_do(regdb,
                                                  regdb_delete_subkey_action,
                                                  &delete_ctx));

done:
        talloc_free(mem_ctx);
        return werr;
}

static TDB_DATA regdb_fetch_key_internal(struct db_context *db,
                                         TALLOC_CTX *mem_ctx, const char *key)
{
        char *path = NULL;
        TDB_DATA data;

        path = normalize_reg_path(mem_ctx, key);
        if (!path) {
                return make_tdb_data(NULL, 0);
        }

        data = dbwrap_fetch_bystring(db, mem_ctx, path);

        TALLOC_FREE(path);
        return data;
}


/**
 * Check for the existence of a key.
 *
 * Existence of a key is authoritatively defined by
 * the existence of the record that contains the list
 * of its subkeys.
 *
 * Return false, if the record does not match the correct
 * structure of an initial 4-byte counter and then a
 * list of the corresponding number of zero-terminated
 * strings.
 */
static bool regdb_key_exists(struct db_context *db, const char *key)
{
        TALLOC_CTX *mem_ctx = talloc_stackframe();
        TDB_DATA value;
        bool ret = false;
        char *path;
        uint32_t buflen;
        const char *buf;
        uint32_t num_items, i;
        int32_t len;

        if (key == NULL) {
                goto done;
        }

        path = normalize_reg_path(mem_ctx, key);
        if (path == NULL) {
                DEBUG(0, ("out of memory! (talloc failed)\n"));
                goto done;
        }

        if (*path == '\0') {
                goto done;
        }

        value = regdb_fetch_key_internal(db, mem_ctx, path);
        if (value.dptr == NULL) {
                goto done;
        }

        if (value.dsize == 0) {
                DEBUG(10, ("regdb_key_exists: subkeylist-record for key "
                          "[%s] is empty: Could be a deleted record in a "
                          "clustered (ctdb) environment?\n",
                          path));
                goto done;
        }

        len = tdb_unpack(value.dptr, value.dsize, "d", &num_items);
        if (len == (int32_t)-1) {
                DEBUG(1, ("regdb_key_exists: ERROR: subkeylist-record for key "
                          "[%s] is invalid: Could not parse initial 4-byte "
                          "counter. record data length is %u.\n",
                          path, (unsigned int)value.dsize));
                goto done;
        }

        /*
         * Note: the tdb_unpack check above implies that len <= value.dsize
         */
        buflen = value.dsize - len;
        buf = (const char *)value.dptr + len;

        len = 0;

        for (i = 0; i < num_items; i++) {
                if (buflen == 0) {
                        break;
                }
                len = strnlen(buf, buflen) + 1;
                if (buflen < len) {
                        DEBUG(1, ("regdb_key_exists: ERROR: subkeylist-record "
                                  "for key [%s] is corrupt: %u items expected, "
                                  "item number %u is not zero terminated.\n",
                                  path, num_items, i+1));
                        goto done;
                }

                buf += len;
                buflen -= len;
        }

        if (buflen > 0) {
                DEBUG(1, ("regdb_key_exists: ERROR: subkeylist-record for key "
                          "[%s] is corrupt: %u items expected and found, but "
                          "the record contains additional %u bytes\n",
                          path, num_items, buflen));
                goto done;
        }

        if (i < num_items) {
                DEBUG(1, ("regdb_key_exists: ERROR: subkeylist-record for key "
                          "[%s] is corrupt: %u items expected, but only %u "
                          "items found.\n",
                          path, num_items, i+1));
                goto done;
        }

        ret = true;

done:
        TALLOC_FREE(mem_ctx);
        return ret;
}


/***********************************************************************
 Retrieve an array of strings containing subkeys.  Memory should be
 released by the caller.
 ***********************************************************************/

static WERROR regdb_fetch_keys_internal(struct db_context *db, const char *key,
                                        struct regsubkey_ctr *ctr)
{
        WERROR werr;
        uint32_t num_items;
        uint8 *buf;
        uint32 buflen, len;
        int i;
        fstring subkeyname;
        TALLOC_CTX *frame = talloc_stackframe();
        TDB_DATA value;

        DEBUG(11,("regdb_fetch_keys: Enter key => [%s]\n", key ? key : "NULL"));

        if (!regdb_key_exists(db, key)) {
                DEBUG(10, ("key [%s] not found\n", key));
                werr = WERR_NOT_FOUND;
                goto done;
        }

        werr = regsubkey_ctr_reinit(ctr);
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regsubkey_ctr_set_seqnum(ctr, db->get_seqnum(db));
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        value = regdb_fetch_key_internal(db, frame, key);

        if (value.dsize == 0 || value.dptr == NULL) {
                DEBUG(10, ("regdb_fetch_keys: no subkeys found for key [%s]\n",
                           key));
                goto done;
        }

        buf = value.dptr;
        buflen = value.dsize;
        len = tdb_unpack( buf, buflen, "d", &num_items);
        if (len == (uint32_t)-1) {
                werr = WERR_NOT_FOUND;
                goto done;
        }

        for (i=0; i<num_items; i++) {
                len += tdb_unpack(buf+len, buflen-len, "f", subkeyname);
                werr = regsubkey_ctr_addkey(ctr, subkeyname);
                if (!W_ERROR_IS_OK(werr)) {
                        DEBUG(5, ("regdb_fetch_keys: regsubkey_ctr_addkey "
                                  "failed: %s\n", win_errstr(werr)));
                        num_items = 0;
                        goto done;
                }
        }

        DEBUG(11,("regdb_fetch_keys: Exit [%d] items\n", num_items));

done:
        TALLOC_FREE(frame);
        return werr;
}

int regdb_fetch_keys(const char *key, struct regsubkey_ctr *ctr)
{
        WERROR werr;

        werr = regdb_fetch_keys_internal(regdb, key, ctr);
        if (!W_ERROR_IS_OK(werr)) {
                return -1;
        }

        return regsubkey_ctr_numkeys(ctr);
}

/****************************************************************************
 Unpack a list of registry values frem the TDB
 ***************************************************************************/

static int regdb_unpack_values(struct regval_ctr *values, uint8 *buf, int buflen)
{
        int             len = 0;
        uint32          type;
        fstring valuename;
        uint32          size;
        uint8           *data_p;
        uint32          num_values = 0;
        int             i;

        /* loop and unpack the rest of the registry values */

        len += tdb_unpack(buf+len, buflen-len, "d", &num_values);

        for ( i=0; i<num_values; i++ ) {
                /* unpack the next regval */

                type = REG_NONE;
                size = 0;
                data_p = NULL;
                valuename[0] = '\0';
                len += tdb_unpack(buf+len, buflen-len, "fdB",
                                  valuename,
                                  &type,
                                  &size,
                                  &data_p);

                regval_ctr_addvalue(values, valuename, type,
                                (uint8_t *)data_p, size);
                SAFE_FREE(data_p); /* 'B' option to tdb_unpack does a malloc() */

                DEBUG(8,("specific: [%s], len: %d\n", valuename, size));
        }

        return len;
}

/****************************************************************************
 Pack all values in all printer keys
 ***************************************************************************/

static int regdb_pack_values(struct regval_ctr *values, uint8 *buf, int buflen)
{
        int             len = 0;
        int             i;
        struct regval_blob      *val;
        int             num_values;

        if ( !values )
                return 0;

        num_values = regval_ctr_numvals( values );

        /* pack the number of values first */

        len += tdb_pack( buf+len, buflen-len, "d", num_values );

        /* loop over all values */

        for ( i=0; i<num_values; i++ ) {
                val = regval_ctr_specific_value( values, i );
                len += tdb_pack(buf+len, buflen-len, "fdB",
                                regval_name(val),
                                regval_type(val),
                                regval_size(val),
                                regval_data_p(val) );
        }

        return len;
}

/***********************************************************************
 Retrieve an array of strings containing subkeys.  Memory should be
 released by the caller.
 ***********************************************************************/

static int regdb_fetch_values_internal(struct db_context *db, const char* key,
                                       struct regval_ctr *values)
{
        char *keystr = NULL;
        TALLOC_CTX *ctx = talloc_stackframe();
        int ret = 0;
        TDB_DATA value;
        WERROR werr;

        DEBUG(10,("regdb_fetch_values: Looking for value of key [%s] \n", key));

        if (!regdb_key_exists(db, key)) {
                goto done;
        }

        keystr = talloc_asprintf(ctx, "%s\\%s", REG_VALUE_PREFIX, key);
        if (!keystr) {
                goto done;
        }

        werr = regval_ctr_set_seqnum(values, db->get_seqnum(db));
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        value = regdb_fetch_key_internal(db, ctx, keystr);

        if (!value.dptr) {
                /* all keys have zero values by default */
                goto done;
        }

        regdb_unpack_values(values, value.dptr, value.dsize);
        ret = regval_ctr_numvals(values);

done:
        TALLOC_FREE(ctx);
        return ret;
}

int regdb_fetch_values(const char* key, struct regval_ctr *values)
{
        return regdb_fetch_values_internal(regdb, key, values);
}

static bool regdb_store_values_internal(struct db_context *db, const char *key,
                                        struct regval_ctr *values)
{
        TDB_DATA old_data, data;
        char *keystr = NULL;
        TALLOC_CTX *ctx = talloc_stackframe();
        int len;
        NTSTATUS status;
        bool result = false;

        DEBUG(10,("regdb_store_values: Looking for value of key [%s] \n", key));

        if (!regdb_key_exists(db, key)) {
                goto done;
        }

        ZERO_STRUCT(data);

        len = regdb_pack_values(values, data.dptr, data.dsize);
        if (len <= 0) {
                DEBUG(0,("regdb_store_values: unable to pack values. len <= 0\n"));
                goto done;
        }

        data.dptr = talloc_array(ctx, uint8, len);
        data.dsize = len;

        len = regdb_pack_values(values, data.dptr, data.dsize);

        SMB_ASSERT( len == data.dsize );

        keystr = talloc_asprintf(ctx, "%s\\%s", REG_VALUE_PREFIX, key );
        if (!keystr) {
                goto done;
        }
        keystr = normalize_reg_path(ctx, keystr);
        if (!keystr) {
                goto done;
        }

        old_data = dbwrap_fetch_bystring(db, ctx, keystr);

        if ((old_data.dptr != NULL)
            && (old_data.dsize == data.dsize)
            && (memcmp(old_data.dptr, data.dptr, data.dsize) == 0))
        {
                result = true;
                goto done;
        }

        status = dbwrap_trans_store_bystring(db, keystr, data, TDB_REPLACE);

        result = NT_STATUS_IS_OK(status);

done:
        TALLOC_FREE(ctx);
        return result;
}

bool regdb_store_values(const char *key, struct regval_ctr *values)
{
        return regdb_store_values_internal(regdb, key, values);
}

static WERROR regdb_get_secdesc(TALLOC_CTX *mem_ctx, const char *key,
                                struct security_descriptor **psecdesc)
{
        char *tdbkey;
        TDB_DATA data;
        NTSTATUS status;
        TALLOC_CTX *tmp_ctx = talloc_stackframe();
        WERROR err = WERR_OK;

        DEBUG(10, ("regdb_get_secdesc: Getting secdesc of key [%s]\n", key));

        if (!regdb_key_exists(regdb, key)) {
                err = WERR_BADFILE;
                goto done;
        }

        tdbkey = talloc_asprintf(tmp_ctx, "%s\\%s", REG_SECDESC_PREFIX, key);
        if (tdbkey == NULL) {
                err = WERR_NOMEM;
                goto done;
        }

        tdbkey = normalize_reg_path(tmp_ctx, tdbkey);
        if (tdbkey == NULL) {
                err = WERR_NOMEM;
                goto done;
        }

        data = dbwrap_fetch_bystring(regdb, tmp_ctx, tdbkey);
        if (data.dptr == NULL) {
                err = WERR_BADFILE;
                goto done;
        }

        status = unmarshall_sec_desc(mem_ctx, (uint8 *)data.dptr, data.dsize,
                                     psecdesc);

        if (NT_STATUS_EQUAL(status, NT_STATUS_NO_MEMORY)) {
                err = WERR_NOMEM;
        } else if (!NT_STATUS_IS_OK(status)) {
                err = WERR_REG_CORRUPT;
        }

done:
        TALLOC_FREE(tmp_ctx);
        return err;
}

static WERROR regdb_set_secdesc(const char *key,
                                struct security_descriptor *secdesc)
{
        TALLOC_CTX *mem_ctx = talloc_stackframe();
        char *tdbkey;
        WERROR err = WERR_NOMEM;
        TDB_DATA tdbdata;

        if (!regdb_key_exists(regdb, key)) {
                err = WERR_BADFILE;
                goto done;
        }

        tdbkey = talloc_asprintf(mem_ctx, "%s\\%s", REG_SECDESC_PREFIX, key);
        if (tdbkey == NULL) {
                goto done;
        }

        tdbkey = normalize_reg_path(mem_ctx, tdbkey);
        if (tdbkey == NULL) {
                err = WERR_NOMEM;
                goto done;
        }

        if (secdesc == NULL) {
                /* assuming a delete */
                err = ntstatus_to_werror(dbwrap_trans_delete_bystring(regdb,
                                                                      tdbkey));
                goto done;
        }

        err = ntstatus_to_werror(marshall_sec_desc(mem_ctx, secdesc,
                                                   &tdbdata.dptr,
                                                   &tdbdata.dsize));
        W_ERROR_NOT_OK_GOTO_DONE(err);

        err = ntstatus_to_werror(dbwrap_trans_store_bystring(regdb, tdbkey,
                                                             tdbdata, 0));

 done:
        TALLOC_FREE(mem_ctx);
        return err;
}

bool regdb_subkeys_need_update(struct regsubkey_ctr *subkeys)
{
        return (regdb_get_seqnum() != regsubkey_ctr_get_seqnum(subkeys));
}

bool regdb_values_need_update(struct regval_ctr *values)
{
        return (regdb_get_seqnum() != regval_ctr_get_seqnum(values));
}

/*
 * Table of function pointers for default access
 */

struct registry_ops regdb_ops = {
        .fetch_subkeys = regdb_fetch_keys,
        .fetch_values = regdb_fetch_values,
        .store_subkeys = regdb_store_keys,
        .store_values = regdb_store_values,
        .create_subkey = regdb_create_subkey,
        .delete_subkey = regdb_delete_subkey,
        .get_secdesc = regdb_get_secdesc,
        .set_secdesc = regdb_set_secdesc,
        .subkeys_need_update = regdb_subkeys_need_update,
        .values_need_update = regdb_values_need_update
};