dlz_odbc_driver.c

来自「非常好的dns解析软件」· C语言 代码 · 共 1,569 行 · 第 1/3 页

	}

	return result;
}

/*%
 * If the client is allowed to perform a zone transfer, the next order of
 * business is to get all the nodes in the zone, so bind can respond to the
 * query.
 */

static isc_result_t
odbc_allnodes(const char *zone, void *driverarg, void *dbdata,
	      dns_sdlzallnodes_t *allnodes)
{

	isc_result_t result;
	dbinstance_t *dbi = NULL;
	SQLHSTMT  *stmnt;
	SQLSMALLINT fields;
	char *data;
	char *type;
	char *ttl_s;
	int ttl;
	char *host;
	char *endp;

	UNUSED(driverarg);

	/* run the query and get the result set from the database. */
	result = odbc_get_resultset(zone, NULL, NULL, ALLNODES, dbdata, &dbi);

	/* if we get "not implemented", send it along */
	if (result == ISC_R_NOTIMPLEMENTED)
		return result;

	/* if we didn't get a result set, log an err msg. */
	if (result != ISC_R_SUCCESS) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Odbc driver unable to return "
			      "result set for all nodes query");
		return (ISC_R_FAILURE);
	}

	stmnt = ((odbc_db_t *) (dbi->dbconn))->stmnt;

	/* get number of columns */
	if (!sqlOK(SQLNumResultCols(stmnt, &fields))) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Odbc driver unable to process result set");
		result = ISC_R_FAILURE;
		goto allnodes_cleanup;
	}

	if (fields < 4) {	/* gotta have at least 4 columns */
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Odbc driver too few fields returned by "
			      "all nodes query");
		result = ISC_R_FAILURE;
		goto allnodes_cleanup;
	}

	/* get things ready for processing */
	result = ISC_R_FAILURE;

	while (sqlOK(SQLFetch(stmnt))) {

		/* set to null for next pass through */
		data = host = type = ttl_s = NULL;

		/*
		 * attempt to get DNS ttl, type, host, data then tell
		 * Bind about them
		 */
		if ((result = odbc_getField(stmnt, 1,
					    &ttl_s)) == ISC_R_SUCCESS &&
		    (result = odbc_getField(stmnt, 2,
					    &type)) == ISC_R_SUCCESS &&
		    (result = odbc_getField(stmnt, 3,
					    &host)) == ISC_R_SUCCESS &&
		    (result = odbc_getManyFields(stmnt, 4, fields,
						 &data)) == ISC_R_SUCCESS) {
			/* convert ttl string to int */
			ttl = strtol(ttl_s, &endp, 10);
			/* failure converting ttl. */
			if (*endp != '\0' || ttl < 0) {
				isc_log_write(dns_lctx,
					      DNS_LOGCATEGORY_DATABASE,
					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
					      "Odbc driver ttl must be "
					      "a postive number");
				result = ISC_R_FAILURE;
			} else {
				/* successful converting TTL, tell Bind  */
				result = dns_sdlz_putnamedrr(allnodes, host,
							     type, ttl, data);
			}
		} /* closes big if () */

		/* clean up mem */
		if (ttl_s != NULL)
			isc_mem_free(ns_g_mctx, ttl_s);
		if (type != NULL)
			isc_mem_free(ns_g_mctx, type);
		if (host != NULL)
			isc_mem_free(ns_g_mctx, host);
		if (data != NULL)
			isc_mem_free(ns_g_mctx, data);

		/* if we weren't successful, log err msg */
		if (result != ISC_R_SUCCESS) {
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
				      "dns_sdlz_putnamedrr returned error. "
				      "Error code was: %s",
				      isc_result_totext(result));
			result = ISC_R_FAILURE;
			goto allnodes_cleanup;
		}
	} /* closes while loop */

 allnodes_cleanup:

	/* close cursor */
	SQLCloseCursor(((odbc_db_t *) (dbi->dbconn))->stmnt);

#ifdef ISC_PLATFORM_USETHREADS

	/* free lock on dbi so someone else can use it. */
	isc_mutex_unlock(&dbi->instance_lock);

#endif

	return result;
}

/*%
 * if the lookup function does not return SOA or NS records for the zone,
 * use this function to get that information for Bind.
 */

static isc_result_t
odbc_authority(const char *zone, void *driverarg, void *dbdata,
	       dns_sdlzlookup_t *lookup)
{
	isc_result_t result;
	dbinstance_t *dbi = NULL;

	UNUSED(driverarg);

	/* run the query and get the result set from the database. */
	result = odbc_get_resultset(zone, NULL, NULL, AUTHORITY, dbdata, &dbi);
	/* if we get "not implemented", send it along */
	if (result == ISC_R_NOTIMPLEMENTED)
		return result;
	/* if we didn't get a result set, log an err msg. */
	if (result != ISC_R_SUCCESS) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Odbc driver unable to return "
			      "result set for authority query");
		return (ISC_R_FAILURE);
	}
	/* lookup and authority result sets are processed in the same manner */
	/* odbc_process_rs does the job for both functions. */
	return odbc_process_rs(lookup, dbi);
}

/*% if zone is supported, lookup up a (or multiple) record(s) in it */

static isc_result_t
odbc_lookup(const char *zone, const char *name, void *driverarg,
	    void *dbdata, dns_sdlzlookup_t *lookup)
{
	isc_result_t result;
	dbinstance_t *dbi = NULL;

	UNUSED(driverarg);

	/* run the query and get the result set from the database. */
	result = odbc_get_resultset(zone, name, NULL, LOOKUP, dbdata, &dbi);
	/* if we didn't get a result set, log an err msg. */
	if (result != ISC_R_SUCCESS) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Odbc driver unable to return "
			      "result set for lookup query");
		return (ISC_R_FAILURE);
	}
	/* lookup and authority result sets are processed in the same manner */
	/* odbc_process_rs does the job for both functions. */
	return odbc_process_rs(lookup, dbi);
}

/*%
 * create an instance of the driver.  Remember, only 1 copy of the driver's
 * code is ever loaded, the driver has to remember which context it's
 * operating in.  This is done via use of the dbdata argument which is
 * passed into all query functions.
 */
static isc_result_t
odbc_create(const char *dlzname, unsigned int argc, char *argv[],
	    void *driverarg, void **dbdata)
{
	isc_result_t result;
	odbc_instance_t *odbc_inst = NULL;
	dbinstance_t *db = NULL;
	SQLRETURN sqlRes;

#ifdef ISC_PLATFORM_USETHREADS
	/* if multi-threaded, we need a few extra variables. */
	int dbcount;
	int i;
	char *endp;

#endif /* ISC_PLATFORM_USETHREADS */

	UNUSED(dlzname);
	UNUSED(driverarg);

#ifdef ISC_PLATFORM_USETHREADS
	/* if debugging, let user know we are multithreaded. */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(1),
		      "Odbc driver running multithreaded");
#else /* ISC_PLATFORM_USETHREADS */
	/* if debugging, let user know we are single threaded. */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(1),
		      "Odbc driver running single threaded");
#endif /* ISC_PLATFORM_USETHREADS */

	/* verify we have at least 5 arg's passed to the driver */
	if (argc < 5) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Odbc driver requires at least "
			      "4 command line args.");
		return (ISC_R_FAILURE);
	}

	/* no more than 8 arg's should be passed to the driver */
	if (argc > 8) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Odbc driver cannot accept more than "
			      "7 command line args.");
		return (ISC_R_FAILURE);
	}

	/* multithreaded build can have multiple DB connections */
#ifdef ISC_PLATFORM_USETHREADS

	/* check how many db connections we should create */
	dbcount = strtol(argv[1], &endp, 10);
	if (*endp != '\0' || dbcount < 0) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Odbc driver database connection count "
			      "must be positive.");
		return (ISC_R_FAILURE);
	}

#endif /* ISC_PLATFORM_USETHREADS */

	/* allocate memory for odbc instance */
	odbc_inst = isc_mem_get(ns_g_mctx, sizeof(odbc_instance_t));
	if (odbc_inst == NULL)
		return (ISC_R_NOMEMORY);
	memset(odbc_inst, 0, sizeof(odbc_instance_t));

	/* parse connection string and get paramters. */

	/* get odbc database dsn - required */
	odbc_inst->dsn = (SQLCHAR *) getParameterValue(argv[2],
						       "dsn=");
	if (odbc_inst->dsn == NULL) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "odbc driver requires a dns parameter.");
		result = ISC_R_FAILURE;
		goto cleanup;
	}
	/* get odbc database username */
	/* if no username was passed, set odbc_inst.user = NULL; */
	odbc_inst->user = (SQLCHAR *) getParameterValue(argv[2],
							"user=");

	/* get odbc database password */
	/* if no password was passed, set odbc_inst.pass = NULL; */
	odbc_inst->pass = (SQLCHAR *) getParameterValue(argv[2], "pass=");

	/* create odbc environment & set environment to ODBC V3 */
	if (odbc_inst->sql_env == NULL) {
		/* create environment handle */
		sqlRes = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE,
					&(odbc_inst->sql_env));
		if (!sqlOK(sqlRes)) {
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_INFO,
				      "Odbc driver unable to allocate memory");
			result = ISC_R_NOMEMORY;
			goto cleanup;
		}
		/*set ODBC version = 3 */
		sqlRes = SQLSetEnvAttr(odbc_inst->sql_env,
				       SQL_ATTR_ODBC_VERSION,
				       (void *) SQL_OV_ODBC3, 0);
		if (!sqlOK(sqlRes)) {
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_INFO,
				      "Unable to configure ODBC environment");
			result = ISC_R_NOMEMORY;
			goto cleanup;
		}
	}

#ifdef ISC_PLATFORM_USETHREADS

	/* allocate memory for database connection list */
	odbc_inst->db = isc_mem_get(ns_g_mctx, sizeof(db_list_t));
	if (odbc_inst->db == NULL) {
		result = ISC_R_NOMEMORY;
		goto cleanup;
	}


	/* initialize DB connection list */
	ISC_LIST_INIT(*odbc_inst->db);

	/* create the appropriate number of database instances (DBI) */
	/* append each new DBI to the end of the list */
	for (i=0; i < dbcount; i++) {

#endif /* ISC_PLATFORM_USETHREADS */

		/* how many queries were passed in from config file? */
		switch(argc) {
		case 5:
			result = build_sqldbinstance(ns_g_mctx, NULL, NULL,
						     NULL, argv[3], argv[4],
						     NULL, &db);
			break;
		case 6:
			result = build_sqldbinstance(ns_g_mctx, NULL, NULL,
						     argv[5], argv[3], argv[4],
						     NULL, &db);
			break;
		case 7:
			result = build_sqldbinstance(ns_g_mctx, argv[6], NULL,
						     argv[5], argv[3], argv[4],
						     NULL, &db);
			break;
		case 8:
			result = build_sqldbinstance(ns_g_mctx, argv[6],
						     argv[7], argv[5], argv[3],
						     argv[4], NULL, &db);
			break;
		default:
			/* not really needed, should shut up compiler. */
			result = ISC_R_FAILURE;
		}

		/* unsuccessful?, log err msg and cleanup. */
		if (result != ISC_R_SUCCESS) {
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
				      "Odbc driver could not create "
				      "database instance object.");
			goto cleanup;
		}

#ifdef ISC_PLATFORM_USETHREADS

		/* when multithreaded, build a list of DBI's */
		ISC_LINK_INIT(db, link);
		ISC_LIST_APPEND(*odbc_inst->db, db, link);

#endif

		result = odbc_connect(odbc_inst, (odbc_db_t **) &(db->dbconn));

		if (result != ISC_R_SUCCESS) {

#ifdef ISC_PLATFORM_USETHREADS

			/*
			 * if multi threaded, let user know which
			 * connection failed.  user could be
			 * attempting to create 10 db connections and
			 * for some reason the db backend only allows
			 * 9.
			 */
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
				      "Odbc driver failed to create database "
				      "connection number %u after 3 attempts",
				      i+1);
#else
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
				      "Odbc driver failed to create database "
				      "connection after 3 attempts");
#endif
			goto cleanup;
		}

#ifdef ISC_PLATFORM_USETHREADS

		/* set DB = null for next loop through. */
		db = NULL;

	}	/* end for loop */

#else
	/* tell odbc_inst about the db connection we just created. */
	odbc_inst->db = db;

#endif

	/* set dbdata to the odbc_instance we created. */
	*dbdata = odbc_inst;

	/* hey, we got through all of that ok, return success. */
	return(ISC_R_SUCCESS);

 cleanup:

	destroy_odbc_instance(odbc_inst);

	return result;
}

/*%
 * destroy an instance of the driver.  Remember, only 1 copy of the driver's
 * code is ever loaded, the driver has to remember which context it's
 * operating in.  This is done via use of the dbdata argument.
 * so we really only need to clean it up since we are not using driverarg.
 */

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

	destroy_odbc_instance((odbc_instance_t *) dbdata);
}


/* pointers to all our runtime methods. */
/* this is used during driver registration */
/* i.e. in dlz_odbc_init below. */
static dns_sdlzmethods_t dlz_odbc_methods = {
	odbc_create,
	odbc_destroy,
	odbc_findzone,
	odbc_lookup,
	odbc_authority,
	odbc_allnodes,
	odbc_allowzonexfr
};

/*%
 * Wrapper around dns_sdlzregister().
 */
isc_result_t
dlz_odbc_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 odbc driver.");

	/*
	 * Driver is always threadsafe.  When multithreaded all
	 * functions use multithreaded code.  When not multithreaded,
	 * all functions can only be entered once, but only 1 thread
	 * of operation is available in Bind.  So everything is still
	 * threadsafe.
	 */
	result = dns_sdlzregister("odbc", &dlz_odbc_methods, NULL,
				  DNS_SDLZFLAG_RELATIVEOWNER |
				  DNS_SDLZFLAG_RELATIVERDATA |
				  DNS_SDLZFLAG_THREADSAFE,
				  ns_g_mctx, &dlz_odbc);
	/* if we can't register the driver, there are big problems. */
	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_odbc_clear(void) {

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

	/* unregister the driver. */
	if (dlz_odbc != NULL)
		dns_sdlzunregister(&dlz_odbc);
}

#endif