regdb: use db_open_trans()

[Samba/gbeck.git] / source / registry / reg_backend_db.c

/* 
 *  Unix SMB/CIFS implementation.
 *  Virtual Windows Registry Layer
 *  Copyright (C) Gerald Carter                     2002-2005
 *
 *  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"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_REGISTRY

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

/* 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_SHARES,
        KEY_EVENTLOG,
        KEY_SMBCONF,
        KEY_PERFLIB,
        KEY_PERFLIB_009,
        "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 } }
};

/**
 * Initialize a key in the registry:
 * create each component key of the specified path.
 */
static bool init_registry_key_internal(const char *add_path)
{
        bool ret = false;
        TALLOC_CTX *frame = talloc_stackframe();
        char *path = NULL;
        char *base = NULL;
        char *remaining = NULL;
        char *keyname;
        char *subkeyname;
        REGSUBKEY_CTR *subkeys;
        const char *p, *p2;

        DEBUG(6, ("init_registry_key: Adding [%s]\n", add_path));

        path = talloc_strdup(frame, add_path);
        base = talloc_strdup(frame, "");
        if (!path || !base) {
                goto fail;
        }
        p = path;

        while (next_token_talloc(frame, &p, &keyname, "\\")) {

                /* build up the registry path from the components */

                if (*base) {
                        base = talloc_asprintf(frame, "%s\\", base);
                        if (!base) {
                                goto fail;
                        }
                }
                base = talloc_asprintf_append(base, "%s", keyname);
                if (!base) {
                        goto fail;
                }

                /* get the immediate subkeyname (if we have one ) */

                subkeyname = talloc_strdup(frame, "");
                if (!subkeyname) {
                        goto fail;
                }
                if (*p) {
                        remaining = talloc_strdup(frame, p);
                        if (!remaining) {
                                goto fail;
                        }
                        p2 = remaining;

                        if (!next_token_talloc(frame, &p2,
                                                &subkeyname, "\\"))
                        {
                                subkeyname = talloc_strdup(frame,p2);
                                if (!subkeyname) {
                                        goto fail;
                                }
                        }
                }

                DEBUG(10,("init_registry_key: Storing key [%s] with "
                          "subkey [%s]\n", base,
                          *subkeyname ? subkeyname : "NULL"));

                /* we don't really care if the lookup succeeds or not
                 * since we are about to update the record.
                 * We just want any subkeys already present */

                if (!(subkeys = TALLOC_ZERO_P(frame, REGSUBKEY_CTR))) {
                        DEBUG(0,("talloc() failure!\n"));
                        goto fail;
                }

                regdb_fetch_keys(base, subkeys);
                if (*subkeyname) {
                        regsubkey_ctr_addkey( subkeys, subkeyname);
                }
                if (!regdb_store_keys( base, subkeys)) {
                        goto fail;
                }
        }

        ret = true;
fail:
        TALLOC_FREE(frame);
        return ret;
}

/**
 * Initialize a key in the registry:
 * create each component key of the specified path,
 * wrapped in one db transaction.
 */
bool init_registry_key(const char *add_path)
{
        if (regdb->transaction_start(regdb) != 0) {
                DEBUG(0, ("init_registry_key: transaction_start failed\n"));
                return false;
        }

        if (!init_registry_key_internal(add_path)) {
                goto fail;
        }

        if (regdb->transaction_commit(regdb) == -1) {
                DEBUG(0, ("init_registry_key: Could not commit transaction\n"));
                return false;
        }

        return true;

fail:
        if (regdb->transaction_cancel(regdb) == -1) {
                smb_panic("init_registry_key: transaction_cancel failed\n");
        }

        return false;
}

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

bool init_registry_data(void)
{
        TALLOC_CTX *frame = NULL;
        REGVAL_CTR *values;
        int i;
        UNISTR2 data;

        /*
         * 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.
         */

        if (regdb->transaction_start(regdb) != 0) {
                DEBUG(0, ("init_registry_data: tdb_transaction_start "
                          "failed\n"));
                return false;
        }

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

        for (i=0; builtin_registry_paths[i] != NULL; i++) {
                if (!init_registry_key_internal(builtin_registry_paths[i])) {
                        goto fail;
                }
        }

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

        frame = talloc_stackframe();

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

                values = TALLOC_ZERO_P(frame, REGVAL_CTR);
                if (values == NULL) {
                        goto fail;
                }

                regdb_fetch_values(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))
                {
                        switch(builtin_registry_values[i].type) {
                        case REG_DWORD:
                                regval_ctr_addvalue(values,
                                        builtin_registry_values[i].valuename,
                                        REG_DWORD,
                                        (char*)&builtin_registry_values[i].data.dw_value,
                                        sizeof(uint32));
                                break;

                        case REG_SZ:
                                init_unistr2(&data,
                                        builtin_registry_values[i].data.string,
                                        UNI_STR_TERMINATE);
                                regval_ctr_addvalue(values,
                                        builtin_registry_values[i].valuename,
                                        REG_SZ,
                                        (char*)data.buffer,
                                        data.uni_str_len*sizeof(uint16));
                                break;

                        default:
                                DEBUG(0, ("init_registry_data: invalid value "
                                          "type in builtin_registry_values "
                                          "[%d]\n",
                                          builtin_registry_values[i].type));
                        }
                        regdb_store_values(builtin_registry_values[i].path,
                                           values);
                }
                TALLOC_FREE(values);
        }

        TALLOC_FREE(frame);

        if (regdb->transaction_commit(regdb) == -1) {
                DEBUG(0, ("init_registry_data: Could not commit "
                          "transaction\n"));
                return false;
        }

        return true;

 fail:

        TALLOC_FREE(frame);

        if (regdb->transaction_cancel(regdb) == -1) {
                smb_panic("init_registry_data: tdb_transaction_cancel "
                          "failed\n");
        }

        return false;
}

/***********************************************************************
 Open the registry database
 ***********************************************************************/
 
bool regdb_init(void)
{
        const char *vstring = "INFO/version";
        uint32 vers_id;

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

        regdb = db_open_trans(NULL, state_path("registry.tdb"), 0,
                              REG_TDB_FLAGS, O_RDWR, 0600);
        if (!regdb) {
                regdb = db_open_trans(NULL, state_path("registry.tdb"), 0,
                                      REG_TDB_FLAGS, O_RDWR|O_CREAT, 0600);
                if (!regdb) {
                        DEBUG(0,("regdb_init: Failed to open registry %s (%s)\n",
                                state_path("registry.tdb"), strerror(errno) ));
                        return false;
                }
                
                DEBUG(10,("regdb_init: Successfully created registry tdb\n"));
        }

        regdb_refcount = 1;

        vers_id = dbwrap_fetch_int32(regdb, vstring);

        if ( vers_id != REGVER_V1 ) {
                /* any upgrade code here if needed */
                DEBUG(10, ("regdb_init: got %s = %d != %d\n", vstring,
                           vers_id, REGVER_V1));
                if (dbwrap_trans_store_int32(regdb, vstring, REGVER_V1) != 0) {
                        DEBUG(0, ("regdb_init: error storing %s = %d\n",
                                  vstring, REGVER_V1));
                        return false;
                } else {
                        DEBUG(10, ("regdb_init: stored %s = %d\n",
                                  vstring, REGVER_V1));
                }
        }

        return true;
}

/***********************************************************************
 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)\n", regdb_refcount));
                regdb_refcount++;
                return WERR_OK;
        }
        
        become_root();

        regdb = db_open_trans(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: 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)\n", regdb_refcount));

        if ( regdb_refcount > 0 )
                return 0;

        SMB_ASSERT( regdb_refcount >= 0 );

        TALLOC_FREE(regdb);
        return 0;
}

/***********************************************************************
 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);
}

/***********************************************************************
 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 bool regdb_store_keys_internal(const char *key, REGSUBKEY_CTR *ctr)
{
        TDB_DATA dbuf;
        uint8 *buffer = NULL;
        int i = 0;
        uint32 len, buflen;
        bool ret = true;
        uint32 num_subkeys = regsubkey_ctr_numkeys(ctr);
        char *keyname = NULL;
        TALLOC_CTX *ctx = talloc_stackframe();
        NTSTATUS status;

        if (!key) {
                return false;
        }

        keyname = talloc_strdup(ctx, key);
        if (!keyname) {
                return false;
        }
        keyname = normalize_reg_path(ctx, keyname);

        /* allocate some initial memory */

        buffer = (uint8 *)SMB_MALLOC(1024);
        if (buffer == NULL) {
                return false;
        }
        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++) {
                len += tdb_pack(buffer+len, buflen-len, "f",
                                regsubkey_ctr_specific_key(ctr, i));
                if (len > buflen) {
                        /* allocate some extra space */
                        buffer = (uint8 *)SMB_REALLOC(buffer, len*2);
                        if(buffer == NULL) {
                                DEBUG(0, ("regdb_store_keys: Failed to realloc "
                                          "memory of size [%d]\n", len*2));
                                ret = false;
                                goto done;
                        }
                        buflen = len*2;
                        len = tdb_pack(buffer+len, buflen-len, "f",
                                       regsubkey_ctr_specific_key(ctr, i));
                }
        }

        /* finally write out the data */

        dbuf.dptr = buffer;
        dbuf.dsize = len;
        status = dbwrap_store_bystring(regdb, keyname, dbuf, TDB_REPLACE);
        if (!NT_STATUS_IS_OK(status)) {
                ret = false;
                goto done;
        }

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

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

bool regdb_store_keys(const char *key, REGSUBKEY_CTR *ctr)
{
        int num_subkeys, i;
        char *path = NULL;
        REGSUBKEY_CTR *subkeys = NULL, *old_subkeys = NULL;
        char *oldkeyname = NULL;
        TALLOC_CTX *ctx = talloc_stackframe();
        NTSTATUS status;

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

        if (!(old_subkeys = TALLOC_ZERO_P(ctx, REGSUBKEY_CTR))) {
                DEBUG(0,("regdb_store_keys: talloc() failure!\n"));
                return false;
        }

        regdb_fetch_keys(key, old_subkeys);

        if ((ctr->num_subkeys && old_subkeys->num_subkeys) &&
            (ctr->num_subkeys == old_subkeys->num_subkeys)) {

                for (i = 0; i<ctr->num_subkeys; i++) {
                        if (strcmp(ctr->subkeys[i],
                                   old_subkeys->subkeys[i]) != 0) {
                                break;
                        }
                }
                if (i == ctr->num_subkeys) {
                        /*
                         * Nothing changed, no point to even start a tdb
                         * transaction
                         */
                        TALLOC_FREE(old_subkeys);
                        return true;
                }
        }

        TALLOC_FREE(old_subkeys);

        if (regdb->transaction_start(regdb) != 0) {
                DEBUG(0, ("regdb_store_keys: transaction_start failed\n"));
                goto fail;
        }

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

        if (!(old_subkeys = TALLOC_ZERO_P(ctx, REGSUBKEY_CTR))) {
                DEBUG(0,("regdb_store_keys: talloc() failure!\n"));
                goto cancel;
        }

        regdb_fetch_keys(key, old_subkeys);

        /* store the subkey list for the parent */

        if (!regdb_store_keys_internal(key, ctr) ) {
                DEBUG(0,("regdb_store_keys: Failed to store new subkey list "
                         "for parent [%s]\n", key));
                goto cancel;
        }

        /* now delete removed keys */

        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(ctr, oldkeyname)) {
                        /*
                         * It's still around, don't delete
                         */

                        continue;
                }

                path = talloc_asprintf(ctx, "%s/%s", key, oldkeyname);
                if (!path) {
                        goto cancel;
                }
                path = normalize_reg_path(ctx, path);
                if (!path) {
                        goto cancel;
                }
                status = dbwrap_delete_bystring(regdb, path);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(1, ("Deleting %s failed\n", path));
                        goto cancel;
                }

                TALLOC_FREE(path);
                path = talloc_asprintf(ctx, "%s/%s/%s",
                                REG_VALUE_PREFIX,
                                key,
                                oldkeyname );
                if (!path) {
                        goto cancel;
                }
                path = normalize_reg_path(ctx, path);
                if (!path) {
                        goto cancel;
                }

                /*
                 * Ignore errors here, we might have no values around
                 */
                dbwrap_delete_bystring(regdb, path);
                TALLOC_FREE(path);
        }

        TALLOC_FREE(old_subkeys);

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

        num_subkeys = regsubkey_ctr_numkeys(ctr);

        if (num_subkeys == 0) {
                if (!(subkeys = TALLOC_ZERO_P(ctx, REGSUBKEY_CTR)) ) {
                        DEBUG(0,("regdb_store_keys: talloc() failure!\n"));
                        goto cancel;
                }

                if (!regdb_store_keys_internal(key, subkeys)) {
                        DEBUG(0,("regdb_store_keys: Failed to store "
                                 "new record for key [%s]\n", key));
                        goto cancel;
                }
                TALLOC_FREE(subkeys);

        }

        for (i=0; i<num_subkeys; i++) {
                path = talloc_asprintf(ctx, "%s/%s",
                                        key,
                                        regsubkey_ctr_specific_key(ctr, i));
                if (!path) {
                        goto cancel;
                }
                if (!(subkeys = TALLOC_ZERO_P(ctx, REGSUBKEY_CTR)) ) {
                        DEBUG(0,("regdb_store_keys: talloc() failure!\n"));
                        goto cancel;
                }

                if (regdb_fetch_keys( path, subkeys ) == -1) {
                        /* create a record with 0 subkeys */
                        if (!regdb_store_keys_internal(path, subkeys)) {
                                DEBUG(0,("regdb_store_keys: Failed to store "
                                         "new record for key [%s]\n", path));
                                goto cancel;
                        }
                }

                TALLOC_FREE(subkeys);
                TALLOC_FREE(path);
        }

        if (regdb->transaction_commit(regdb) == -1) {
                DEBUG(0, ("regdb_store_keys: Could not commit transaction\n"));
                goto fail;
        }

        TALLOC_FREE(ctx);
        return true;

cancel:
        if (regdb->transaction_cancel(regdb) == -1) {
                smb_panic("regdb_store_keys: transaction_cancel failed\n");
        }

fail:
        TALLOC_FREE(ctx);

        return false;
}


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

int regdb_fetch_keys(const char *key, REGSUBKEY_CTR *ctr)
{
        char *path = NULL;
        uint32 num_items;
        uint8 *buf;
        uint32 buflen, len;
        int i;
        fstring subkeyname;
        int ret = -1;
        TALLOC_CTX *frame = talloc_stackframe();
        TDB_DATA value;

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

        path = talloc_strdup(frame, key);
        if (!path) {
                goto fail;
        }

        /* convert to key format */
        path = talloc_string_sub(frame, path, "\\", "/");
        if (!path) {
                goto fail;
        }
        strupper_m(path);

        ret = regdb->fetch(regdb, frame, string_term_tdb_data(path), &value);
        if (ret != 0) {
                ret = 0;
                goto fail;
        }

        ctr->seqnum = regdb_get_seqnum();

        buf = value.dptr;
        buflen = value.dsize;

        if ( !buf ) {
                DEBUG(5,("regdb_fetch_keys: tdb lookup failed to locate key [%s]\n", key));
                goto fail;
        }

        len = tdb_unpack( buf, buflen, "d", &num_items);

        for (i=0; i<num_items; i++) {
                len += tdb_unpack(buf+len, buflen-len, "f", subkeyname);
                regsubkey_ctr_addkey(ctr, subkeyname);
        }

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

        ret = num_items;
 fail:
        TALLOC_FREE(frame);
        return ret;
}

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

static int regdb_unpack_values(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);

                /* add the new value. Paranoid protective code -- make sure data_p is valid */

                if (*valuename && size && data_p) {
                        regval_ctr_addvalue(values, valuename, type,
                                        (const char *)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(REGVAL_CTR *values, uint8 *buf, int buflen)
{
        int             len = 0;
        int             i;
        REGISTRY_VALUE  *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.
 ***********************************************************************/

int regdb_fetch_values( const char* key, REGVAL_CTR *values )
{
        char *keystr = NULL;
        TALLOC_CTX *ctx = talloc_stackframe();
        int ret = 0;
        TDB_DATA value;

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

        keystr = talloc_asprintf(ctx, "%s/%s", REG_VALUE_PREFIX, key);
        if (!keystr) {
                return 0;
        }
        keystr = normalize_reg_path(ctx, keystr);
        if (!keystr) {
                goto done;
        }

        ret = regdb->fetch(regdb, ctx, string_term_tdb_data(keystr), &value);
        if (ret != 0) {
                ret = 0;
                goto done;
        }

        values->seqnum = regdb_get_seqnum();

        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;
}

bool regdb_store_values( const char *key, REGVAL_CTR *values )
{
        TDB_DATA old_data, data;
        char *keystr = NULL;
        TALLOC_CTX *ctx = talloc_stackframe();
        int len, ret;
        bool result = false;

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

        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(regdb, 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;
        }

        ret = dbwrap_trans_store(regdb, string_term_tdb_data(keystr), data,
                                 TDB_REPLACE);
        result = (ret != -1);

done:
        TALLOC_FREE(ctx);
        return result;
}

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));

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

        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;
        int tdb_ret;

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

        if (secdesc == NULL) {
                /* assuming a delete */
                tdb_ret = dbwrap_trans_delete(regdb,
                                              string_term_tdb_data(tdbkey));
                if (tdb_ret == -1) {
                        err = ntstatus_to_werror(map_nt_error_from_unix(errno));
                } else {
                        err = WERR_OK;
                }
                goto done;
        }

        err = ntstatus_to_werror(marshall_sec_desc(mem_ctx, secdesc,
                                                   &tdbdata.dptr,
                                                   &tdbdata.dsize));
        if (!W_ERROR_IS_OK(err)) {
                goto done;
        }

        tdb_ret = dbwrap_trans_store(regdb, string_term_tdb_data(tdbkey),
                                     tdbdata, 0);
        if (tdb_ret == -1) {
                err = ntstatus_to_werror(map_nt_error_from_unix(errno));
                goto done;
        }

 done:
        TALLOC_FREE(mem_ctx);
        return err;
}

bool regdb_subkeys_need_update(REGSUBKEY_CTR *subkeys)
{
        return (regdb_get_seqnum() != subkeys->seqnum);
}

bool regdb_values_need_update(REGVAL_CTR *values)
{
        return (regdb_get_seqnum() != values->seqnum);
}

/* 
 * Table of function pointers for default access
 */
 
REGISTRY_OPS regdb_ops = {
        .fetch_subkeys = regdb_fetch_keys,
        .fetch_values = regdb_fetch_values,
        .store_subkeys = regdb_store_keys,
        .store_values = regdb_store_values,
        .get_secdesc = regdb_get_secdesc,
        .set_secdesc = regdb_set_secdesc,
        .subkeys_need_update = regdb_subkeys_need_update,
        .values_need_update = regdb_values_need_update
};