dlz_bdb_driver.c

来自「非常好的dns解析软件」· C语言 代码 · 共 798 行 · 第 1/2 页

	bdb_instance_t *db = (bdb_instance_t *) dbdata;
	DBC *zone_cursor = NULL;
	DBT key, data;

	UNUSED(driverarg);

	memset(&key, 0, sizeof(DBT));
	memset(&data, 0, sizeof(DBT));
	data.flags = DB_DBT_MALLOC;

	key.data = strdup(name);

	if (key.data == NULL)
		return (ISC_R_NOMEMORY);

	key.size = strlen(key.data);

	/* get a cursor to loop through zone data */
	if (db->zone->cursor(db->zone, NULL, &zone_cursor, 0) != 0) {
		result = ISC_R_NOTFOUND;
		goto findzone_cleanup;
	}

	switch(zone_cursor->c_get(zone_cursor, &key, &data, DB_SET)) {
	case DB_NOTFOUND:
	case DB_SECONDARY_BAD:
		result = ISC_R_NOTFOUND;
		break;
	case 0:
		result = ISC_R_SUCCESS;
		break;
	default:
		result = ISC_R_FAILURE;
	}

 findzone_cleanup:

	/* free any memory duplicate string in the key field */
	if (key.data != NULL)
		free(key.data);

	/* free any memory allocated to the data field. */
	if (data.data != NULL)
		free(data.data);

	/* get rid of zone_cursor */
	if (zone_cursor != NULL)
		zone_cursor->c_close(zone_cursor);

	return result;
}

static isc_result_t
bdb_lookup(const char *zone, const char *name, void *driverarg,
	   void *dbdata, dns_sdlzlookup_t *lookup)
{

	isc_result_t result = ISC_R_NOTFOUND;
	bdb_instance_t *db = (bdb_instance_t *) dbdata;
	DBC *zone_cursor = NULL;
	DBC *host_cursor = NULL;
	DBC *join_cursor = NULL;
	DBT key, data;
	DBC *cur_arr[3];
	int bdbres;
	parsed_data_t pd;
	char *tmp_zone, *tmp_host = NULL;
	char *tmp = NULL;

	UNUSED(driverarg);

	memset(&key, 0, sizeof(DBT));
	memset(&data, 0, sizeof(DBT));

	/* set zone key */
	key.data = tmp_zone = strdup(zone);
	if (key.data == NULL) {
		result = ISC_R_NOMEMORY;
		goto lookup_cleanup;
	}
	key.size = strlen(key.data);

	/* get a cursor to loop through zone data */
	if (db->zone->cursor(db->zone, NULL, &zone_cursor, 0) != 0) {
		result = ISC_R_FAILURE;
		goto lookup_cleanup;
	}

	/* initialize zone_cursor with zone_key */
	if (zone_cursor->c_get(zone_cursor, &key, &data, DB_SET) != 0) {
		result = ISC_R_NOTFOUND;
		goto lookup_cleanup;
	}

	/* set host key */
	key.data = tmp_host = strdup(name);
	if (key.data == NULL) {
		result = ISC_R_NOMEMORY;
		goto lookup_cleanup;
	}
	key.size = strlen(key.data);

	/* get a cursor to loop through host data */
	if (db->host->cursor(db->host, NULL, &host_cursor, 0) != 0) {
		result = ISC_R_FAILURE;
		goto lookup_cleanup;
	}

	/* initialize host_cursor with host_key */
	if (host_cursor->c_get(host_cursor, &key, &data, DB_SET) != 0) {
		result = ISC_R_NOTFOUND;
		goto lookup_cleanup;
	}

	cur_arr[0] = zone_cursor;
	cur_arr[1] = host_cursor;
	cur_arr[2] = NULL;

	db->data->join(db->data, cur_arr, &join_cursor, 0);

	while ((bdbres = join_cursor->c_get(join_cursor, &key,
					    &data, 0)) == 0) {

		tmp = realloc(tmp, data.size + 1);
		if (tmp == NULL)
			goto lookup_cleanup;

		strncpy(tmp, data.data, data.size);
		tmp[data.size] = '\0';

		if (bdb_parse_data(tmp, &pd) != ISC_R_SUCCESS)
			goto lookup_cleanup;

		result = dns_sdlz_putrr(lookup, pd.type, pd.ttl, pd.data);

		if (result != ISC_R_SUCCESS)
			goto lookup_cleanup;
	} /* end while loop */

 lookup_cleanup:

	if (tmp != NULL)
		free(tmp);
	if (tmp_zone != NULL)
		free(tmp_zone);
	if (tmp_host != NULL)
		free(tmp_host);

	/* get rid of the joined cusor */
	if (join_cursor != NULL)
		join_cursor->c_close(join_cursor);

	/* get rid of zone_cursor */
	if (zone_cursor != NULL)
		zone_cursor->c_close(zone_cursor);

	/* get rid of host_cursor */
	if (host_cursor != NULL)
		host_cursor->c_close(host_cursor);

	return result;

	return ISC_R_NOTFOUND;
}


/*% Initializes, sets flags and then opens Berkeley databases. */

static isc_result_t
bdb_opendb(DB_ENV *db_env, DBTYPE db_type, DB **db, const char *db_name,
	   char *db_file, int flags) {

	int result;

	/* Initialize the database. */
	if ((result = db_create(db, db_env, 0)) != 0) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "BDB could not initialize %s database. "
			      "BDB error: %s",
			      db_name, db_strerror(result));
		return ISC_R_FAILURE;
	}

	/* set database flags. */
	if ((result = (*db)->set_flags(*db, flags)) != 0) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "BDB could not set flags for %s database. "
			      "BDB error: %s",
			      db_name, db_strerror(result));
		return ISC_R_FAILURE;
	}

	/* open the database. */
	if ((result = (*db)->open(*db, NULL, db_file, db_name, db_type,
				  DB_RDONLY | bdb_threads, 0)) != 0) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "BDB could not open %s database in %s. "
			      "BDB error: %s",
			      db_name, db_file, db_strerror(result));
		return ISC_R_FAILURE;
	}

	return ISC_R_SUCCESS;
}

static isc_result_t
bdb_create(const char *dlzname, unsigned int argc, char *argv[],
	   void *driverarg, void **dbdata)
{
	isc_result_t result;
	int bdbres;
	bdb_instance_t *db = NULL;

	UNUSED(dlzname);
	UNUSED(driverarg);

	/* verify we have 3 arg's passed to the driver */
	if (argc != 3) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Berkeley DB driver requires at least "
			      "2 command line args.");
		return (ISC_R_FAILURE);
	}

	/* allocate and zero memory for driver structure */
	db = isc_mem_get(ns_g_mctx, sizeof(bdb_instance_t));
	if (db == NULL) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Could not allocate memory for "
			      "database instance object.");
		return (ISC_R_NOMEMORY);
	}
	memset(db, 0, sizeof(bdb_instance_t));

	/* attach to the memory context */
	isc_mem_attach(ns_g_mctx, &db->mctx);

	/* create BDB environment
	 * Basically BDB allocates and assigns memory to db->dbenv
	 */
	bdbres = db_env_create(&db->dbenv, 0);
	if (bdbres != 0) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "BDB environment could not be created. "
			      "BDB error: %s",
			      db_strerror(bdbres));
		result = ISC_R_FAILURE;
		goto init_cleanup;
	}

	/* open BDB environment */
	bdbres = db->dbenv->open(db->dbenv, argv[1],
				 DB_INIT_CDB | DB_INIT_MPOOL |
				 bdb_threads | DB_CREATE,
				 0);
	if (bdbres != 0) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "BDB environment at '%s' could not be opened. "
			      "BDB error: %s",
			      argv[1], db_strerror(bdbres));
		result = ISC_R_FAILURE;
		goto init_cleanup;
	}

	/* open dlz_data database. */
	result = bdb_opendb(db->dbenv, DB_UNKNOWN, &db->data,
			    dlz_data, argv[2], 0);
	if (result != ISC_R_SUCCESS)
		goto init_cleanup;

	/* open dlz_host database. */
	result = bdb_opendb(db->dbenv, DB_UNKNOWN, &db->host,
			    dlz_host, argv[2],
			    DB_DUP | DB_DUPSORT);
	if (result != ISC_R_SUCCESS)
		goto init_cleanup;

	/* open dlz_zone database. */
	result = bdb_opendb(db->dbenv, DB_UNKNOWN, &db->zone,
			    dlz_zone, argv[2],
			    DB_DUP | DB_DUPSORT);
	if (result != ISC_R_SUCCESS)
		goto init_cleanup;

	/* open dlz_client database. */
	result = bdb_opendb(db->dbenv, DB_UNKNOWN, &db->client,
			    dlz_client, argv[2], DB_DUP | DB_DUPSORT);
	if (result != ISC_R_SUCCESS)
		goto init_cleanup;

	/* associate the host secondary database with the primary database */
	bdbres = db->data->associate(db->data, NULL, db->host, NULL, 0);
	if (bdbres != 0) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "BDB could not associate %s database with %s. "
			      "BDB error: %s",
			      dlz_host, dlz_data, db_strerror(bdbres));
		result = ISC_R_FAILURE;
		goto init_cleanup;
	}

	/* associate the zone secondary database with the primary database */
	bdbres = db->data->associate(db->data, NULL, db->zone, NULL, 0);
	if (bdbres != 0) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "BDB could not associate %s database with %s. "
			      "BDB error: %s",
			      dlz_zone, dlz_data, db_strerror(bdbres));
		result = ISC_R_FAILURE;
		goto init_cleanup;
	}

	*dbdata = db;

	return(ISC_R_SUCCESS);

 init_cleanup:

	bdb_cleanup(db);
	return result;
}

static void
bdb_destroy(void *driverarg, void *dbdata)
{
	UNUSED(driverarg);

	bdb_cleanup((bdb_instance_t *) dbdata);
}

/* bdb_authority not needed as authority data is returned by lookup */
static dns_sdlzmethods_t dlz_bdb_methods = {
	bdb_create,
	bdb_destroy,
	bdb_findzone,
	bdb_lookup,
	NULL,
	bdb_allnodes,
	bdb_allowzonexfr
};

/*%
 * Wrapper around dns_sdlzregister().
 */
isc_result_t
dlz_bdb_init(void) {
	isc_result_t result;

	/*
	 * Write debugging message to log
	 */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
		      "Registering DLZ bdb driver.");

	result = dns_sdlzregister("bdb", &dlz_bdb_methods, NULL,
				  DNS_SDLZFLAG_RELATIVEOWNER |
				  DNS_SDLZFLAG_RELATIVERDATA |
				  DNS_SDLZFLAG_THREADSAFE,
				  ns_g_mctx, &dlz_bdb);
	if (result != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "dns_sdlzregister() failed: %s",
				 isc_result_totext(result));
		result = ISC_R_UNEXPECTED;
	}


	return result;
}

/*%
 * Wrapper around dns_sdlzunregister().
 */
void
dlz_bdb_clear(void) {

	/*
	 * Write debugging message to log
	 */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
		      "Unregistering DLZ bdb driver.");

	if (dlz_bdb != NULL)
		dns_sdlzunregister(&dlz_bdb);
}

#endif