jist.runtime
Class ProxyPoint

java.lang.Object
  jist.runtime.ProxyPoint

public class ProxyPoint
extends java.lang.Object

Firewall and NAT-busting functionality for JiST (and any RMI client). Basic idea is to avoid any incoming connections. All parties make outgoing connections to the central ProxyPoint, and the ProxyPoint connects people up and marshalls information back and forth. None of this is very efficient, but it works well enough to hooks up scores of clients to scores of servers all over the world! In other words, it's one big hack that does the job.

Since:

JIST1.0

Version:

$Id: ProxyPoint.java,v 1.11 2004/04/06 16:07:43 barr Exp $

Author:

Rimon Barr <barr+jist@cs.cornell.edu>

Nested Class Summary

static class	ProxyPoint.ProxyAcceptSocket A Socket on the server-side that operates via the ProxyPoint proxy.
static class	ProxyPoint.ProxyClientSocket A Socket on the client-side that operates via the ProxyPoint proxy.
static class	ProxyPoint.ProxyServerSocket A ServerSocket that operates via the ProxyPoint proxy.
static class	ProxyPoint.ProxySocketFactory An RMI socket factory that returns proxied sockets.
static class	ProxyPoint.StreamPump A Runnable object that pumps from an InputStream to an OutputStream.

Field Summary

static byte	COMMAND_CONNECT proxy server command constant.
static byte	COMMAND_CONNECTED proxy server command constant.
static byte	COMMAND_INVALID proxy server command constant.
static byte	COMMAND_LISTEN proxy server command constant.
static byte	COMMAND_NOOP proxy server command constant.
static boolean	DEBUG whether to show some output.
private java.util.Hashtable	listen listen sockets: SocketAddress -- Socket.
static int	PROXY_PORT default proxy server port.
private java.net.ServerSocket	ss proxy server listen socket.

Constructor Summary

ProxyPoint(int port)
Create a new ProxyPoint server object.

Method Summary

void	accept() Block for and process a single incoming connection.
private int	getUnusedPort(java.net.InetAddress addr) Return an unused proxied port number for given address.
static void	main(java.lang.String[] args) Entry point to start a proxy point server.
static void	pumpSocket(java.net.Socket s1, java.net.Socket s2) Pump data between two sockets in both directions, and close both if one fails.
static java.net.InetAddress	readInetAddress(java.io.ObjectInputStream is) Read and parse IP address from input stream.
static void	setRmiProxy(java.net.InetAddress host, int port) Set global RMI proxy factory to proxy sockets to given proxy server.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

PROXY_PORT

public static final int PROXY_PORT

default proxy server port.

See Also:

Constant Field Values

COMMAND_INVALID

public static final byte COMMAND_INVALID

proxy server command constant.

See Also:

Constant Field Values

COMMAND_NOOP

public static final byte COMMAND_NOOP

proxy server command constant.

See Also:

Constant Field Values

COMMAND_LISTEN

public static final byte COMMAND_LISTEN

proxy server command constant.

See Also:

Constant Field Values

COMMAND_CONNECT

public static final byte COMMAND_CONNECT

proxy server command constant.

See Also:

Constant Field Values

COMMAND_CONNECTED

public static final byte COMMAND_CONNECTED

proxy server command constant.

See Also:

Constant Field Values

DEBUG

public static final boolean DEBUG

whether to show some output.

See Also:

Constant Field Values

ss

private java.net.ServerSocket ss

proxy server listen socket.

listen

private java.util.Hashtable listen

listen sockets: SocketAddress -- Socket.

Constructor Detail

ProxyPoint

public ProxyPoint(int port)
           throws java.io.IOException

Create a new ProxyPoint server object.

Parameters:

port - port for incoming connections

Throws:

java.io.IOException - when i/o fails

Method Detail

setRmiProxy

public static void setRmiProxy(java.net.InetAddress host,
                               int port)
                        throws java.io.IOException

Set global RMI proxy factory to proxy sockets to given proxy server. This methods tests the server first with a quick "ping" connection, and then sets the socket factory.

Parameters:

host - proxy server host

port - proxy server port

Throws:

java.io.IOException - when i/o fails

pumpSocket

public static void pumpSocket(java.net.Socket s1,
                              java.net.Socket s2)
                       throws java.io.IOException

Pump data between two sockets in both directions, and close both if one fails. This method is not particularly efficient... it creates three threads to deal with the work, rather than performing selects, and non-blocking i/o.

Parameters:

s1 - first socket to pump

s2 - second socket to pump

Throws:

java.io.IOException - when i/o fails (before pumping begins)

readInetAddress

public static java.net.InetAddress readInetAddress(java.io.ObjectInputStream is)
                                            throws java.io.IOException

Read and parse IP address from input stream.

Parameters:

is - input stream to read

Returns:

IP address read

Throws:

java.io.IOException - when i/o fails

getUnusedPort

private int getUnusedPort(java.net.InetAddress addr)

Return an unused proxied port number for given address.

Parameters:

addr - machine requesting unused port

Returns:

unused proxied port at given address

accept

public void accept()

Block for and process a single incoming connection.

main

public static void main(java.lang.String[] args)

Entry point to start a proxy point server.

Parameters:

args - command-line parameters