s4:samr Use ldb_context * rather than void *

[Samba/gbeck.git] / source3 / 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;

static bool regdb_key_exists(const char *key);
static bool regdb_key_is_base_key(const char *key);

/* 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,
        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,
        KEY_WINLOGON_GPEXT_PATH,
        "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 WERROR init_registry_key_internal(const char *add_path)
{
        WERROR werr;
        TALLOC_CTX *frame = talloc_stackframe();
        char *path = NULL;
        char *base = NULL;
        char *remaining = NULL;
        char *keyname;
        char *subkeyname;
        struct 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) {
                werr = WERR_NOMEM;
                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) {
                                werr = WERR_NOMEM;
                                goto fail;
                        }
                }
                base = talloc_asprintf_append(base, "%s", keyname);
                if (!base) {
                        werr = WERR_NOMEM;
                        goto fail;
                }

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

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

                        if (!next_token_talloc(frame, &p2,
                                                &subkeyname, "\\"))
                        {
                                subkeyname = talloc_strdup(frame,p2);
                                if (!subkeyname) {
                                        werr = WERR_NOMEM;
                                        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 */

                werr = regsubkey_ctr_init(frame, &subkeys);
                if (!W_ERROR_IS_OK(werr)) {
                        DEBUG(0,("talloc() failure!\n"));
                        goto fail;
                }

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

        werr = WERR_OK;

fail:
        TALLOC_FREE(frame);
        return werr;
}

/**
 * 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)
{
        WERROR werr;

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

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

        werr = init_registry_key_internal(add_path);
        if (!W_ERROR_IS_OK(werr)) {
                goto fail;
        }

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

        return WERR_OK;

fail:
        if (regdb->transaction_cancel(regdb) != 0) {
                smb_panic("init_registry_key: transaction_cancel failed\n");
        }

        return werr;
}

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

WERROR init_registry_data(void)
{
        WERROR werr;
        TALLOC_CTX *frame = talloc_stackframe();
        REGVAL_CTR *values;
        int i;
        UNISTR2 data;

        /*
         * 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(builtin_registry_paths[i])) {
                        goto do_init;
                }
        }

        for (i=0; builtin_registry_values[i].path != NULL; i++) {
                values = TALLOC_ZERO_P(frame, REGVAL_CTR);
                if (values == NULL) {
                        werr = WERR_NOMEM;
                        goto done;
                }

                regdb_fetch_values(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.
         */

        if (regdb->transaction_start(regdb) != 0) {
                DEBUG(0, ("init_registry_data: tdb_transaction_start "
                          "failed\n"));
                werr = WERR_REG_IO_FAILURE;
                goto done;
        }

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

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

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

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

                values = TALLOC_ZERO_P(frame, REGVAL_CTR);
                if (values == NULL) {
                        werr = WERR_NOMEM;
                        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);
        }

        if (regdb->transaction_commit(regdb) != 0) {
                DEBUG(0, ("init_registry_data: Could not commit "
                          "transaction\n"));
                werr = WERR_REG_IO_FAILURE;
        } else {
                werr = WERR_OK;
        }

        goto done;

fail:
        if (regdb->transaction_cancel(regdb) != 0) {
                smb_panic("init_registry_data: tdb_transaction_cancel "
                          "failed\n");
        }

done:
        TALLOC_FREE(frame);
        return werr;
}

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

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

        vers_id = dbwrap_fetch_int32(regdb, vstring);

        if ( vers_id != REGVER_V1 ) {
                NTSTATUS status;
                /* any upgrade code here if needed */
                DEBUG(10, ("regdb_init: got %s = %d != %d\n", vstring,
                           vers_id, REGVER_V1));
                status = dbwrap_trans_store_int32(regdb, vstring, REGVER_V1);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(1, ("regdb_init: error storing %s = %d: %s\n",
                                  vstring, REGVER_V1, nt_errstr(status)));
                        return ntstatus_to_werror(status);
                } else {
                        DEBUG(10, ("regdb_init: stored %s = %d\n",
                                  vstring, REGVER_V1));
                }
        }

        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)\n", regdb_refcount));
                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: 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;
}

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(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(regdb, 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(const char *keyname)
{
        return regdb_delete_key_with_prefix(keyname, REG_VALUE_PREFIX);
}

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

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

static WERROR regdb_delete_key_lists(const char *keyname)
{
        WERROR werr;

        werr = regdb_delete_values(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(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(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 bool regdb_store_keys_internal(const char *key, struct 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++) {
                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));
                                ret = false;
                                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"));
                                ret = false;
                                goto done;
                        }
                }
                len += thistime;
        }

        /* 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;
        }

        /*
         * Delete a sorted subkey cache for regdb_key_exists, will be
         * recreated automatically
         */
        keyname = talloc_asprintf(ctx, "%s/%s", REG_SORTED_SUBKEYS_PREFIX,
                                  keyname);
        if (keyname != NULL) {
                dbwrap_delete_bystring(regdb, keyname);
        }

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, struct regsubkey_ctr *ctr)
{
        int num_subkeys, old_num_subkeys, i;
        char *path = NULL;
        struct regsubkey_ctr *subkeys = NULL, *old_subkeys = NULL;
        char *oldkeyname = NULL;
        TALLOC_CTX *ctx = talloc_stackframe();
        WERROR werr;

        if (!regdb_key_is_base_key(key) && !regdb_key_exists(key)) {
                goto fail;
        }

        /*
         * 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"));
                return false;
        }

        regdb_fetch_keys(key, old_subkeys);

        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
                         */
                        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
         */

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

        regdb_fetch_keys(key, old_subkeys);

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

                        continue;
                }

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

                werr = regdb_delete_key_lists(path);
                W_ERROR_NOT_OK_GOTO(werr, cancel);

                TALLOC_FREE(path);
        }

        TALLOC_FREE(old_subkeys);

        /* (2) 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;
        }

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

        num_subkeys = regsubkey_ctr_numkeys(ctr);

        if (num_subkeys == 0) {
                werr = regsubkey_ctr_init(ctx, &subkeys);
                if (!W_ERROR_IS_OK(werr)) {
                        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;
                }
                werr = regsubkey_ctr_init(ctx, &subkeys);
                if (!W_ERROR_IS_OK(werr)) {
                        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) != 0) {
                DEBUG(0, ("regdb_store_keys: Could not commit transaction\n"));
                goto fail;
        }

        TALLOC_FREE(ctx);
        return true;

cancel:
        if (regdb->transaction_cancel(regdb) != 0) {
                smb_panic("regdb_store_keys: transaction_cancel failed\n");
        }

fail:
        TALLOC_FREE(ctx);

        return false;
}

static WERROR regdb_create_subkey(const char *key, const char *subkey)
{
        WERROR werr;
        struct regsubkey_ctr *subkeys;
        TALLOC_CTX *mem_ctx = talloc_stackframe();

        if (!regdb_key_is_base_key(key) && !regdb_key_exists(key)) {
                werr = WERR_NOT_FOUND;
                goto done;
        }

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

        if (regdb_fetch_keys(key, subkeys) < 0) {
                werr = WERR_REG_IO_FAILURE;
                goto done;
        }

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

        talloc_free(subkeys);

        werr = regdb_transaction_start();
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regsubkey_ctr_init(mem_ctx, &subkeys);
        W_ERROR_NOT_OK_GOTO(werr, cancel);

        if (regdb_fetch_keys(key, subkeys) < 0) {
                werr = WERR_REG_IO_FAILURE;
                goto cancel;
        }

        werr = regsubkey_ctr_addkey(subkeys, subkey);
        W_ERROR_NOT_OK_GOTO(werr, cancel);

        if (!regdb_store_keys_internal(key, subkeys)) {
                DEBUG(0, (__location__ " failed to store new subkey list for "
                         "parent key %s\n", key));
                werr = WERR_REG_IO_FAILURE;
                goto cancel;
        }

        werr = regdb_transaction_commit();
        if (!W_ERROR_IS_OK(werr)) {
                DEBUG(0, (__location__ " failed to commit transaction: %s\n",
                         win_errstr(werr)));
        }

        goto done;

cancel:
        werr = regdb_transaction_cancel();
        if (!W_ERROR_IS_OK(werr)) {
                DEBUG(0, (__location__ " failed to cancel transaction: %s\n",
                         win_errstr(werr)));
        }

done:
        talloc_free(mem_ctx);
        return werr;
}

static WERROR regdb_delete_subkey(const char *key, const char *subkey)
{
        WERROR werr, werr2;
        struct regsubkey_ctr *subkeys;
        char *path;
        TALLOC_CTX *mem_ctx = talloc_stackframe();

        if (!regdb_key_is_base_key(key) && !regdb_key_exists(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(path)) {
                werr = WERR_OK;
                goto done;
        }

        werr = regdb_transaction_start();
        W_ERROR_NOT_OK_GOTO_DONE(werr);

        werr = regdb_delete_key_lists(path);
        W_ERROR_NOT_OK_GOTO(werr, cancel);

        werr = regsubkey_ctr_init(mem_ctx, &subkeys);
        W_ERROR_NOT_OK_GOTO(werr, cancel);

        if (regdb_fetch_keys(key, subkeys) < 0) {
                werr = WERR_REG_IO_FAILURE;
                goto cancel;
        }

        werr = regsubkey_ctr_delkey(subkeys, subkey);
        W_ERROR_NOT_OK_GOTO(werr, cancel);

        if (!regdb_store_keys_internal(key, subkeys)) {
                DEBUG(0, (__location__ " failed to store new subkey_list for "
                         "parent key %s\n", key));
                werr = WERR_REG_IO_FAILURE;
                goto cancel;
        }

        werr = regdb_transaction_commit();
        if (!W_ERROR_IS_OK(werr)) {
                DEBUG(0, (__location__ " failed to commit transaction: %s\n",
                         win_errstr(werr)));
        }

        goto done;

cancel:
        werr2 = regdb_transaction_cancel();
        if (!W_ERROR_IS_OK(werr2)) {
                DEBUG(0, (__location__ " failed to cancel transaction: %s\n",
                         win_errstr(werr2)));
        }

done:
        talloc_free(mem_ctx);
        return werr;
}

static TDB_DATA regdb_fetch_key_internal(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(regdb, mem_ctx, path);

        TALLOC_FREE(path);
        return data;
}


/**
 * check whether a given key name represents a base key,
 * i.e one without a subkey separator ('/' or '\').
 */
static bool regdb_key_is_base_key(const char *key)
{
        TALLOC_CTX *mem_ctx = talloc_stackframe();
        bool ret = false;
        char *path;

        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;
        }

        ret = (strrchr(path, '/') == NULL);

done:
        TALLOC_FREE(mem_ctx);
        return ret;
}

/*
 * regdb_key_exists() is a very frequent operation. It can be quite
 * time-consuming to fully fetch the parent's subkey list, talloc_strdup all
 * subkeys and then compare the keyname linearly to all the parent's subkeys.
 *
 * The following code tries to make this operation as efficient as possible:
 * Per registry key we create a list of subkeys that is very efficient to
 * search for existence of a subkey. Its format is:
 *
 * 4 bytes num_subkeys
 * 4*num_subkey bytes offset into the string array
 * then follows a sorted list of subkeys in uppercase
 *
 * This record is created by create_sorted_subkeys() on demand if it does not
 * exist. scan_parent_subkeys() uses regdb->parse_record to search the sorted
 * list, the parsing code and the binary search can be found in
 * parent_subkey_scanner. The code uses parse_record() to avoid a memcpy of
 * the potentially large subkey record.
 *
 * The sorted subkey record is deleted in regdb_store_keys_internal and
 * recreated on demand.
 */

static int cmp_keynames(const void *p1, const void *p2)
{
        return StrCaseCmp(*((char **)p1), *((char **)p2));
}

static bool create_sorted_subkeys(const char *key, const char *sorted_keyname)
{
        char **sorted_subkeys;
        struct regsubkey_ctr *ctr;
        bool result = false;
        NTSTATUS status;
        char *buf;
        char *p;
        int i, res;
        size_t len;
        int num_subkeys;
        WERROR werr;

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

        werr = regsubkey_ctr_init(talloc_tos(), &ctr);
        if (!W_ERROR_IS_OK(werr)) {
                goto fail;
        }

        res = regdb_fetch_keys(key, ctr);
        if (res == -1) {
                goto fail;
        }

        num_subkeys = regsubkey_ctr_numkeys(ctr);
        sorted_subkeys = talloc_array(ctr, char *, num_subkeys);
        if (sorted_subkeys == NULL) {
                goto fail;
        }

        len = 4 + 4*num_subkeys;

        for (i = 0; i < num_subkeys; i++) {
                sorted_subkeys[i] = talloc_strdup_upper(sorted_subkeys,
                                        regsubkey_ctr_specific_key(ctr, i));
                if (sorted_subkeys[i] == NULL) {
                        goto fail;
                }
                len += strlen(sorted_subkeys[i])+1;
        }

        qsort(sorted_subkeys, num_subkeys, sizeof(char *), cmp_keynames);

        buf = talloc_array(ctr, char, len);
        if (buf == NULL) {
                goto fail;
        }
        p = buf + 4 + 4*num_subkeys;

        SIVAL(buf, 0, num_subkeys);

        for (i=0; i < num_subkeys; i++) {
                ptrdiff_t offset = p - buf;
                SIVAL(buf, 4 + 4*i, offset);
                strlcpy(p, sorted_subkeys[i], len-offset);
                p += strlen(sorted_subkeys[i]) + 1;
        }

        status = dbwrap_store_bystring(
                regdb, sorted_keyname, make_tdb_data((uint8_t *)buf, len),
                TDB_REPLACE);
        if (!NT_STATUS_IS_OK(status)) {
                /*
                 * Don't use a "goto fail;" here, this would commit the broken
                 * transaction. See below for an explanation.
                 */
                if (regdb->transaction_cancel(regdb) == -1) {
                        DEBUG(0, ("create_sorted_subkeys: transaction_cancel "
                                  "failed\n"));
                }
                TALLOC_FREE(ctr);
                return false;
        }

        result = true;
 fail:
        /*
         * We only get here via the "goto fail" when we did not write anything
         * yet. Using transaction_commit even in a failure case is necessary
         * because this (disposable) call might be nested in other
         * transactions. Doing a cancel here would destroy the possibility of
         * a transaction_commit for transactions that we might be wrapped in.
         */
        if (regdb->transaction_commit(regdb) == -1) {
                DEBUG(0, ("create_sorted_subkeys: transaction_start "
                          "failed\n"));
                goto fail;
        }

        TALLOC_FREE(ctr);
        return result;
}

struct scan_subkey_state {
        char *name;
        bool scanned;
        bool found;
};

static int parent_subkey_scanner(TDB_DATA key, TDB_DATA data,
                                 void *private_data)
{
        struct scan_subkey_state *state =
                (struct scan_subkey_state *)private_data;
        uint32_t num_subkeys;
        uint32_t l, u;

        if (data.dsize < sizeof(uint32_t)) {
                return -1;
        }

        state->scanned = true;
        state->found = false;

        tdb_unpack(data.dptr, data.dsize, "d", &num_subkeys);

        l = 0;
        u = num_subkeys;

        while (l < u) {
                uint32_t idx = (l+u)/2;
                char *s = (char *)data.dptr + IVAL(data.dptr, 4 + 4*idx);
                int comparison = strcmp(state->name, s);

                if (comparison < 0) {
                        u = idx;
                } else if (comparison > 0) {
                        l = idx + 1;
                } else {
                        state->found = true;
                        return 0;
                }
        }
        return 0;
}

static bool scan_parent_subkeys(const char *parent, const char *name)
{
        char *path = NULL;
        char *key = NULL;
        struct scan_subkey_state state = { 0, };
        bool result = false;
        int res;

        state.name = NULL;

        path = normalize_reg_path(talloc_tos(), parent);
        if (path == NULL) {
                goto fail;
        }

        key = talloc_asprintf(talloc_tos(), "%s/%s",
                              REG_SORTED_SUBKEYS_PREFIX, path);
        if (key == NULL) {
                goto fail;
        }

        state.name = talloc_strdup_upper(talloc_tos(), name);
        if (state.name == NULL) {
                goto fail;
        }
        state.scanned = false;

        res = regdb->parse_record(regdb, string_term_tdb_data(key),
                                  parent_subkey_scanner, &state);

        if (state.scanned) {
                result = state.found;
        } else {
                if (!create_sorted_subkeys(path, key)) {
                        goto fail;
                }
                res = regdb->parse_record(regdb, string_term_tdb_data(key),
                                          parent_subkey_scanner, &state);
                if ((res == 0) && (state.scanned)) {
                        result = state.found;
                }
        }

 fail:
        TALLOC_FREE(path);
        TALLOC_FREE(state.name);
        return result;
}

/**
 * Check for the existence of a key.
 *
 * Existence of a key is authoritatively defined by its
 * existence in the list of subkeys of its parent key.
 * The exeption of this are keys without a parent key,
 * i.e. the "base" keys (HKLM, HKCU, ...).
 */
static bool regdb_key_exists(const char *key)
{
        TALLOC_CTX *mem_ctx = talloc_stackframe();
        TDB_DATA value;
        bool ret = false;
        char *path, *p;

        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;
        }

        p = strrchr(path, '/');
        if (p == NULL) {
                /* this is a base key */
                value = regdb_fetch_key_internal(mem_ctx, path);
                ret = (value.dptr != NULL);
        } else {
                *p = '\0';
                ret = scan_parent_subkeys(path, p+1);
        }

done:
        TALLOC_FREE(mem_ctx);
        return ret;
}


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

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

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

        werr = regsubkey_ctr_set_seqnum(ctr, regdb_get_seqnum());
        if (!W_ERROR_IS_OK(werr)) {
                goto done;
        }

        value = regdb_fetch_key_internal(frame, key);

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

        buf = value.dptr;
        buflen = value.dsize;
        len = tdb_unpack( buf, buflen, "d", &num_items);

        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)));
                        goto done;
                }
        }

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

        ret = num_items;
done:
        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));

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

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

        values->seqnum = regdb_get_seqnum();

        value = regdb_fetch_key_internal(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;
}

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;
        NTSTATUS status;
        bool result = false;

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

        if (!regdb_key_exists(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(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;
        }

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

        result = NT_STATUS_IS_OK(status);

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));

        if (!regdb_key_exists(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;
        }
        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;

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

        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 */
                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(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,
        .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
};