dlz_postgres_driver.c

来自「非常好的dns解析软件」· C语言 代码 · 共 1,343 行 · 第 1/3 页

		dbi->client = NULL;
	}

	/* temporary logging message */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
	DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
		      "%d did client", dlz_thread_num);

	/*
	 * what type of query are we going to run?
	 * this time we build the actual query to run.
	 */
	switch(query) {
	case ALLNODES:
		querystring = build_querystring(ns_g_mctx, dbi->allnodes_q);
		break;
	case ALLOWXFR:
		querystring = build_querystring(ns_g_mctx, dbi->allowxfr_q);
		break;
	case AUTHORITY:
		querystring = build_querystring(ns_g_mctx, dbi->authority_q);
		break;
	case FINDZONE:
		querystring = build_querystring(ns_g_mctx, dbi->findzone_q);
		break;
	case LOOKUP:
		querystring = build_querystring(ns_g_mctx, dbi->lookup_q);
		break;
	default:
		/*
		 * this should never happen.  If it does, the code is
		 * screwed up!
		 */
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "Incorrect query flag passed to "
				 "postgres_get_resultset");
		result = ISC_R_UNEXPECTED;
		goto cleanup;
	}

	/* temporary logging message */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
		      "%d built query", dlz_thread_num);

	/* if the querystring is null, Bummer, outta RAM.  UPGRADE TIME!!!   */
	if (querystring  == NULL) {
		result = ISC_R_NOMEMORY;
		goto cleanup;
	}

	/* temporary logging message */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
		      "%d query is '%s'", dlz_thread_num, querystring);

	/*
	 * output the full query string during debug so we can see
	 * what lame error the query has.
	 */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(1),
		      "\nQuery String: %s\n", querystring);

	/* attempt query up to 3 times. */
	for (j=0; j < 3; j++) {
		/* temporary logging message */
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "%d executing query for %d time",
			      dlz_thread_num, j);
		/* try to get result set */
		*rs = PQexec((PGconn *)dbi->dbconn, querystring );
		result = ISC_R_SUCCESS;
		/*
		 * if result set is null, reset DB connection, max 3
		 * attempts.
		 */
		for (i=0; *rs == NULL && i < 3; i++) {
			/* temporary logging message */
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
				      "%d resetting connection",
				      dlz_thread_num);
			result = ISC_R_FAILURE;
			PQreset((PGconn *) dbi->dbconn);
			/* connection ok, break inner loop */
			if (PQstatus((PGconn *) dbi->dbconn) == CONNECTION_OK)
				break;
		}
		/* result set ok, break outter loop */
		if (PQresultStatus(*rs) == PGRES_TUPLES_OK) {
			/* temporary logging message */
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
				      "%d rs ok", dlz_thread_num);
			break;
		} else {
			/* we got a result set object, but it's not right. */
			/* temporary logging message */
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
				      "%d clearing rs", dlz_thread_num);
			PQclear(*rs);	/* get rid of it */
			/* in case this was the last attempt */
			result = ISC_R_FAILURE;
		}
	}

 cleanup:
	/* it's always good to cleanup after yourself */

	/* temporary logging message */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
		      "%d cleaning up", dlz_thread_num);

	/* if we couldn't even allocate DBI, just return NULL */
	if (dbi == NULL)
		return ISC_R_FAILURE;

	/* free dbi->zone string */
	if (dbi->zone != NULL)
		isc_mem_free(ns_g_mctx, dbi->zone);

	/* free dbi->record string */
	if (dbi->record != NULL)
		isc_mem_free(ns_g_mctx, dbi->record);

	/* free dbi->client string */
	if (dbi->client != NULL)
		isc_mem_free(ns_g_mctx, dbi->client);

#ifdef ISC_PLATFORM_USETHREADS

	/* temporary logging message */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
		      "%d unlocking mutex", dlz_thread_num);

	/* release the lock so another thread can use this dbi */
	isc_mutex_unlock(&dbi->instance_lock);

#endif /* ISC_PLATFORM_USETHREADS */

	/* release query string */
	if (querystring  != NULL)
		isc_mem_free(ns_g_mctx, querystring );

	/* temporary logging message */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
		      "%d returning", dlz_thread_num);

	/* return result */
	return result;
}

/*%
 * The processing of result sets for lookup and authority are
 * exactly the same.  So that functionality has been moved
 * into this function to minimize code.
 */

static isc_result_t
postgres_process_rs(dns_sdlzlookup_t *lookup, PGresult *rs)
{
	isc_result_t result;
	unsigned int i;
	unsigned int rows;
	unsigned int fields;
	unsigned int j;
	unsigned int len;
	char *tmpString;
	char *endp;
	int ttl;

	rows = PQntuples(rs);	/* how many rows in result set */
	fields = PQnfields(rs);	/* how many columns in result set */
	for (i=0; i < rows; i++) {
		switch(fields) {
		case 1:
			/*
			 * one column in rs, it's the data field.  use
			 * default type of A record, and default TTL
			 * of 86400
			 */
			result = dns_sdlz_putrr(lookup, "a", 86400,
						PQgetvalue(rs, i, 0));
			break;
		case 2:
			/* two columns, data field, and data type.
			 * use default TTL of 86400.
			 */
			result = dns_sdlz_putrr(lookup, PQgetvalue(rs, i, 0),
						86400, PQgetvalue(rs, i, 1));
			break;
		case 3:
			/* three columns, all data no defaults.
			 * convert text to int, make sure it worked
			 * right.
			 */
			ttl = strtol(PQgetvalue(rs, i, 0), &endp, 10);
			if (*endp != '\0' || ttl < 0) {
				isc_log_write(dns_lctx,
					      DNS_LOGCATEGORY_DATABASE,
					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
					      "Postgres driver ttl must be "
					      "a positive number");
			}
			result = dns_sdlz_putrr(lookup, PQgetvalue(rs, i, 1),
						ttl, PQgetvalue(rs, i, 2));
			break;
		default:
		  	/*
			 * more than 3 fields, concatenate the last
			 * ones together.  figure out how long to make
			 * string
			 */
			for (j=2, len=0; j < fields; j++) {
				len += strlen(PQgetvalue(rs, i, j)) + 1;
			}
			/*
			 * allocate string memory, allow for NULL to
			 * term string
			 */
			tmpString = isc_mem_allocate(ns_g_mctx, len + 1);
			if (tmpString == NULL) {
				/* major bummer, need more ram */
				isc_log_write(dns_lctx,
					      DNS_LOGCATEGORY_DATABASE,
					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
					      "Postgres driver unable to "
					      "allocate memory for "
					      "temporary string");
				PQclear(rs);
				return (ISC_R_FAILURE);	/* Yeah, I'd say! */
			}
			/* copy field to tmpString */
			strcpy(tmpString, PQgetvalue(rs, i, 2));
			/*
			 * concat the rest of fields together, space
			 * between each one.
			 */
			for (j=3; j < fields; j++) {
				strcat(tmpString, " ");
				strcat(tmpString, PQgetvalue(rs, i, j));
			}
			/* convert text to int, make sure it worked right */
			ttl = strtol(PQgetvalue(rs, i, 0), &endp, 10);
			if (*endp != '\0' || ttl < 0) {
				isc_log_write(dns_lctx,
					      DNS_LOGCATEGORY_DATABASE,
					      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
					      "Postgres driver ttl must be "
					      "a postive number");
			}
			/* ok, now tell Bind about it. */
			result = dns_sdlz_putrr(lookup, PQgetvalue(rs, i, 1),
						ttl, tmpString);
			/* done, get rid of this thing. */
			isc_mem_free(ns_g_mctx, tmpString);
		}
		/* I sure hope we were successful */
		if (result != ISC_R_SUCCESS) {
			/* nope, get rid of the Result set, and log a msg */
			PQclear(rs);
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
				      "dns_sdlz_putrr returned error. "
				      "Error code was: %s",
				      isc_result_totext(result));
			return (ISC_R_FAILURE);
		}
	}

	/* free result set memory */
	PQclear(rs);

	/* if we did return results, we are successful */
	if (rows > 0)
		return (ISC_R_SUCCESS);

	/* empty result set, no data found */
	return (ISC_R_NOTFOUND);
}

/*
 * SDLZ interface methods
 */

/*% determine if the zone is supported by (in) the database */

static isc_result_t
postgres_findzone(void *driverarg, void *dbdata, const char *name)
{
	isc_result_t result;
	PGresult *rs = NULL;
	unsigned int rows;
	UNUSED(driverarg);

	/* run the query and get the result set from the database. */
	result = postgres_get_resultset(name, NULL, NULL,
					FINDZONE, dbdata, &rs);
	/* if we didn't get a result set, log an err msg. */
	if (result != ISC_R_SUCCESS) {
		if (rs != NULL)
			PQclear(rs);
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Postgres driver unable to return "
			      "result set for findzone query");
		return (ISC_R_FAILURE);
	}
	/* count how many rows in result set */
	rows = PQntuples(rs);
	/* get rid of result set, we are done with it. */
	PQclear(rs);

	/* if we returned any rows, zone is supported. */
	if (rows > 0)
		return (ISC_R_SUCCESS);

	/* no rows returned, zone is not supported. */
	return (ISC_R_NOTFOUND);
}

/*% Determine if the client is allowed to perform a zone transfer */
static isc_result_t
postgres_allowzonexfr(void *driverarg, void *dbdata, const char *name,
		      const char *client)
{
	isc_result_t result;
	PGresult *rs = NULL;
	unsigned int rows;
	UNUSED(driverarg);

	/* first check if the zone is supported by the database. */
	result = postgres_findzone(driverarg, dbdata, name);
	if (result != ISC_R_SUCCESS)
		return (ISC_R_NOTFOUND);

	/*
	 * if we get to this point we know the zone is supported by
	 * the database the only questions now are is the zone
	 * transfer is allowed for this client and did the config file
	 * have an allow zone xfr query.
	 *
	 * Run our query, and get a result set from the database.
	 */
	result = postgres_get_resultset(name, NULL, client,
					ALLOWXFR, dbdata, &rs);
	/* 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) {
		if (rs != NULL)
			PQclear(rs);
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Postgres driver unable to return "
			      "result set for allow xfr query");
		return (ISC_R_FAILURE);
	}
	/* count how many rows in result set */
	rows = PQntuples(rs);
	/* get rid of result set, we are done with it. */
	PQclear(rs);

	/* if we returned any rows, zone xfr is allowed. */
	if (rows > 0)
		return (ISC_R_SUCCESS);

	/* no rows returned, zone xfr not allowed */
	return (ISC_R_NOPERM);
}

/*%
 * 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
postgres_allnodes(const char *zone, void *driverarg, void *dbdata,
		  dns_sdlzallnodes_t *allnodes)
{
	isc_result_t result;
	PGresult *rs = NULL;
	unsigned int i;
	unsigned int rows;
	unsigned int fields;
	unsigned int j;
	unsigned int len;
	char *tmpString;
	char *endp;
	int ttl;

	UNUSED(driverarg);

	/* run the query and get the result set from the database. */
	result = postgres_get_resultset(zone, NULL, NULL,
					ALLNODES, dbdata, &rs);
	/* 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) {
		if (rs != NULL)
			PQclear(rs);
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Postgres driver unable to return "
			      "result set for all nodes query");
		return (ISC_R_FAILURE);
	}

	rows = PQntuples(rs);	/* how many rows in result set */
	fields = PQnfields(rs);	/* how many columns in result set */
	for (i=0; i < rows; i++) {
		if (fields < 4) {	/* gotta have at least 4 columns */
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
				      "Postgres driver too few fields "
				      "returned by all nodes query");
		}
		/* convert text to int, make sure it worked right  */
		ttl = strtol(PQgetvalue(rs, i, 0), &endp, 10);
		if (*endp != '\0' || ttl < 0) {
			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
				      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
				      "Postgres driver ttl must be "
				      "a postive number");
		}
		if (fields == 4) {
			/* tell Bind about it. */
			result = dns_sdlz_putnamedrr(allnodes,
						     PQgetvalue(rs, i, 2),
						     PQgetvalue(rs, i, 1),
						     ttl,
						     PQgetvalue(rs, i, 3));
		} else {
			/*
			 * more than 4 fields, concatonat the last
			 * ones together.  figure out how long to make
			 * string
			 */
			for (j=3, len=0; j < fields; j++) {