Distinct^® ONC RPC/XDR Toolkit for Java^TM - Version 3.0

Product Overview

The Distinct ONC RPC/XDR Toolkit for Java enables you to write standard ONC RPC clients and servers in pure Java^TM. This CD contains a trial copy of version 3.0 of the Distinct ONC RPC/XDR Toolkit for Java. To use this trial version copy the setup.class file, from the Distinct directory on this CD, onto your local system. It may be installed on any operating system that is running the Java Virtual Machine. Please note that this trial version requires a Windowing system such as Open Windows or Microsoft Windows to be present. The actual version can work with or without a windowing system. Product documentation will be installed on your system in a DOC subdirectory; the documentation is in HTML format. If you are not familiar with the Distinct ONC RPC/XDR Toolkit please read through this overview before proceeding. Please note that Distinct ONC RPC/XDR for Java requires JDK version 1.1 or higher.

The Distinct ONC RPC/XDR Toolkit for Java consists of the following components.

The Distinct ONC RPC/XDR for Java package contains the RPC runtime library. It complies with RFC 1831 (RPC: Remote Procedure Call Protocol Specification Version 2) and RFC 1832 (XDR: External Data Representation Standard). The API consists of classes that allow you to write pure Java clients, for standard RPC servers, that can be embedded in applets and be run by a standard Web browser. It also allows you to develop ONC RPC stand-alone servers. The package allows connections over TCP, UDP or encapsulated over HTTP.

An rpcbind application in Java that implements the rpcbind protocol version 3 and 4. It complies with RFC 1833 (RPC: Binding Protocols for ONC RPC Version 2). A portmapper application in Java that implements portmap interface version 2 is included for backward compatibility.

The Jrpcgen compiler translates standard RPC/XDR interface definition files into the Java source files that implement the client and server side stubs as well as the XDR conversions for the described interface. This means that Jrpcgen implements a Java language mapping for the standard ".x" IDL files. The Jrpcgen additionally supports multiple arguments in function declarations. It is also able to handle multiple program declarations in one .x file.

The RPCInfo utility displays a list of all the services registered with the portmapper on a system. This utility can be used to query the portmapper on the local host (by specifying "localhost" or no host name at all on the command line) or on a remote host (by specifying the name of the host as a command line argument). Source code for the RPCInfo utility is included for reference.

The RPCGw CGI scripts or servlets allow you to execute arbitrary RPCs on the Internet where firewalls usually block protocols, such as RPC, which do not use fixed ports. With RPCGw you can also call RPC servers (from a Java applet) that are not located on the same host as the web server. In order to preserve the integrity and the privacy of your network, RPCGw uses a sophisticated access control list that allows you to specify exactly which procedure of which RPC program and version can be executed on which host via which protocol.

A source code sample for a demo application is included. The demo application consists of an XDR file which describes an interface of a very simple counter server, the server implementation, and a demo applet (along with an HTML page) that invokes the server when the user clicks on it. An additional utility queries the portmapper on the server (which may be the local host) to check if the counter server is currently running. Also included is a demo application which illustrates how to make broadcast RPCs to locate a server.

Version 3 includes support for Secure RPC using AUTH_DES authentication. Support is included for both JCE and Cryptix IJCE. You must install one of these on your system. Be sure to add this to your CLASSPATH and that the cryptography provider is registered in your "/lib/security/java.security" file.

Installation

To install the Distinct ONC RPC/XDR Toolkit for Java on any platform that already has a virtual java machine installed, just copy the setup.class file that is in this subdirectory to you local drive. Then run the setup.class file "java setup" to install the toolkit. Before you can use the toolkit you must add the parent directory of the "distinct" directory (which in turn contains the "rpc" directory) to the CLASSPATH of the Java compiler.

CLICK HERE for automatic installation.

If you are using the Distinct RPC for Java classes to develop an applet which will reside on the server, you should install the Distinct RPC for Java classes below the directory which contains the applet on the server.

All of the online documentation is in HTML format and will be installed in the DOC subfolder. The starting point for the documentation is START.htm. This document contains links to all other parts of the online documentation which includes a programming guide, a class hierarchy, a class reference and an index.

Browser Security

By default all Java-enabled browsers do not allow network connections to hosts other than the one an applet was loaded from. In order to connect your applet to arbitrary RPC servers (or to run an RPC server inside a browser), additional steps are required to work around this restriction.

Either install the RPC application in your local browsers CLASSPATH (similar to a "Helper Application"). This approach is not recommended.

Or use one of the certification/capabilities methods to load your applets as trusted code into a less restricted security domain.

Both methods are currently browser specific. Please check your browser manual for further information or take a look at the security features of Netscape Communicator, HotJava^TM, Microsoft Internet Explorer 4.0. Especially look for the terms "applet security", "signed code" (JAR files, CAB files), and "certificates".

Firewalls

Most RPC applications are designed for Intranets, and although RPC can be made to run over the Internet, the original specifications were not really designed for this. On the Internet connections over arbitrary ports (like those established by the RPC protocol) are often blocked by firewalls. Please ask your firewall administrator for the details of your network security.

Distinct ONC RPC/XDR for Java allows you to build servers and clients with well known (fixed) server ports. Depending on the configuration of your firewall this might already help to access certain servers from the Internet. Distinct ONC RPC/XDR for Java also comes with a powerful mechanism that wraps RPC requests completely with standard HTTP transactions. The server side CGI script (RPCGw) together with an RPC protocol client (ClientHTTP) allow transparent tunneling of the RPC protocol using HTTP. This mechanism allows the execution of arbitrary RPCs on the Internet where firewalls are blocking all protocols, such as RPC, that do not use fixed ports. It also allows you to call RPC servers, from a Java applet, that are not located on the same host as the web server but are elsewhere in your LAN. With this feature you can easily separate the web server from other application or database servers.

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