/*
 * @(#)Inet6AddressImpl.java	1.7 04/01/13 
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package java.net;
import java.io.IOException;

/*
 * Package private implementation of InetAddressImpl for dual
 * IPv4/IPv6 stack.
 * <p>
 * If InetAddress.preferIPv6Address is true then anyLocalAddress(),
 * loopbackAddress(), and localHost() will return IPv6 addresses, 
 * otherwise IPv4 addresses.
 *
 * @since 1.4
 */

class Inet6AddressImpl implements InetAddressImpl {
    public native String getLocalHostName() throws UnknownHostException;
    public native byte[][]
        lookupAllHostAddr(String hostname) throws UnknownHostException;
    public native String getHostByAddr(byte[] addr) throws UnknownHostException;
    private native boolean isReachable0(byte[] addr, int scope, int timeout, byte[] inf, int ttl, int if_scope) throws IOException;

    public boolean isReachable(InetAddress addr, int timeout, NetworkInterface netif, int ttl) throws IOException {
	byte[] ifaddr = null;
	int scope = -1;
	int netif_scope = -1;
	if (netif != null) {
	    /*
	     * Let's make sure we bind to an address of the proper family.
	     * Which means same family as addr because at this point it could
	     * be either an IPv6 address or an IPv4 address (case of a dual
	     * stack system).
	     */
	    java.util.Enumeration it = netif.getInetAddresses();
	    InetAddress inetaddr = null;
	    while (it.hasMoreElements()) {
		inetaddr = (InetAddress) it.nextElement();
		if (inetaddr.getClass().isInstance(addr)) {
		    ifaddr = inetaddr.getAddress();
		    if (inetaddr instanceof Inet6Address) {
			netif_scope = ((Inet6Address) inetaddr).getScopeId();
		    }
		    break;
		}
	    }
	    if (ifaddr == null) {
		// Interface doesn't support the address family of 
		// the destination
		return false;
	    }
	}
	if (addr instanceof Inet6Address)
	    scope = ((Inet6Address) addr).getScopeId();
	return isReachable0(addr.getAddress(), scope, timeout, ifaddr, ttl, netif_scope);
    }

    public synchronized InetAddress anyLocalAddress() {
        if (anyLocalAddress == null) {
            if (InetAddress.preferIPv6Address) {
                anyLocalAddress = new Inet6Address();
                anyLocalAddress.hostName = "::";
            } else {
                anyLocalAddress = (new Inet4AddressImpl()).anyLocalAddress();
            }
        }
        return anyLocalAddress;
    }

    public synchronized InetAddress loopbackAddress() {
        if (loopbackAddress == null) {
             if (InetAddress.preferIPv6Address) {
                 byte[] loopback = 
			{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
                 loopbackAddress = new Inet6Address("localhost", loopback);
             } else {
                loopbackAddress = (new Inet4AddressImpl()).loopbackAddress();
             }
        }
        return loopbackAddress;
    }

    private InetAddress      anyLocalAddress;
    private InetAddress      loopbackAddress;
}