Name: md23716 Date: 10/05/2001

On Solaris 8, a Java process can bind to the same port number as a running IPv6 service. There are no socket exceptions - any IPv4 connections get directed to the Java process, rather than the IPv6 service.

On Solaris 7, the same Java program receives a BindException - "Address already in use". ( This is because Solaris 7 services use IPv4, there is no support for IPv6. )

The problem is occurring on 1.3.1_01 HotSpot JDK, but is fixed in 1.4 under bug 4417734.

To recreate the problem, compile the following testcase and run (as root):

java InUseSocket 23 1000000

Then try to telnet in from a Solaris 7 machine.

-------------------TESTCASE----------------------------------------

import java.net.*;
import java.io.*;

public class InUseSocket
{
    private int port;
    private int timeout;

    public InUseSocket(int _port, int _timeout)
    {
        this.port = _port;
        this.timeout = _timeout;
    }

    public static void main(String[] args)
    {
        if (args.length < 1)
        {
            System.out.println("Usage: InUseSocket <port number> (<timeout>)");
            System.exit(1);
        }

        int _port = 1;

        try
        {
            _port = Integer.parseInt(args[0]);
        }
        catch(Exception e)
        {
            System.out.println("Error invalid port number: " + e);
            System.exit(1);
        }

        int _timeout = 1000;

        if (args.length == 2)
        {
            try
            {
                _timeout = Integer.parseInt(args[1]);
            }
            catch(Exception e)
            {
                System.out.println("Error invalid timeout number: " + e);
                System.exit(1);
            }
        }

        InUseSocket sock = new InUseSocket(_port, _timeout);

        sock.run();
    }

    private void run()
    {
        ServerSocket serverSock = null;

        try
        {
            serverSock = new ServerSocket(port);
            serverSock.setSoTimeout(timeout);
        }
        catch(Exception e)
        {
            System.out.println("Error creating socket: " + e);
            System.exit(1);
        }

        try
        {
            serverSock.accept();
        }
        catch(InterruptedIOException e)
        {
            System.out.println("Finished properly.");
        }
        catch(Exception e)
        {
            System.out.println("Error accepting on socket: " + e);
            System.exit(1);
        }
    }
}



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