ipv4route.java

来自「纯java操作系统jnode,安装简单和操作简单的个人使用的Java操作系统」· Java 代码 · 共 216 行

/*
 * $Id: IPv4Route.java,v 1.1 2003/11/25 11:52:24 epr Exp $
 */
package org.jnode.net.ipv4;

import org.jnode.driver.ApiNotFoundException;
import org.jnode.driver.Device;
import org.jnode.driver.net.NetDeviceAPI;

/**
 * @author epr
 */
public class IPv4Route implements IPv4Constants {

	private final IPv4Address destination;
	private final IPv4Address subnetmask;
	private final IPv4Address gateway;
	private final Device device;
	private int flags;
	private final NetDeviceAPI deviceAPI;
	private int useCount;
	
	/**
	 * Create a new instance
	 * @param destination
	 * @param device
	 * @throws IllegalArgumentException If the device is not a network device.
	 */
	public IPv4Route(IPv4Address destination, Device device) 
	throws IllegalArgumentException {
		this(destination, null, null, device);
	}
	
	/**
	 * Create a new instance
	 * @param destination
	 * @param device
	 * @throws IllegalArgumentException If the device is not a network device.
	 */
	public IPv4Route(IPv4Address destination, IPv4Address subnetmask, Device device) 
	throws IllegalArgumentException {
		this(destination, subnetmask, null, device);
	}
	
	/**
	 * Create a new instance
	 * @param destination
	 * @param gateway
	 * @param device
	 * @throws IllegalArgumentException If the device is not a network device.
	 */
	public IPv4Route(IPv4Address destination, IPv4Address subnetmask, IPv4Address gateway, Device device) 
	throws IllegalArgumentException {
		this.destination = destination;
		if (subnetmask == null) {
			this.subnetmask = destination.getDefaultSubnetmask();
		} else {
			this.subnetmask = subnetmask;
		}
		this.gateway = gateway;
		this.device = device;
		this.flags = RTF_UP;
		if (gateway != null) {
			this.flags |= RTF_GATEWAY;
		}
		try {
			this.deviceAPI = (NetDeviceAPI)device.getAPI(NetDeviceAPI.class);
		} catch (ApiNotFoundException ex) {
			throw new IllegalArgumentException("Device " + device.getId() + " is not a network device");
		}
	}
	
	/**
	 * Is this route up?
	 * @return True if this route is up, false otherwise
	 */
	public boolean isUp() {
		return ((flags & RTF_UP) != 0);
	}

	/**
	 * Is the destination address a host address?
	 * @return True if the destination is a host address, false otherwise
	 * @see #isNetwork()
	 */
	public boolean isHost() {
		return destination.isHost();
	}

	/**
	 * Is the destination address a network address?
	 * @return True if the destination is a network address, false otherwise
	 * @see #isHost()
	 */
	public boolean isNetwork() {
		return destination.isNetwork();
	}
	
	/**
	 * Is this an indirect route?
	 */
	public boolean isGateway() {
		return ((flags & RTF_GATEWAY) != 0);
	}

	/**
	 * Set the gateway flag
	 * @param on
	 * @throws IllegalArgumentException If on is true and no gateway address is set.
	 */
	public void setGateway(boolean on) 
	throws IllegalArgumentException {
		if (on) {
			if (gateway == null) {
				throw new IllegalArgumentException("Cannot set gateway without a gateway address");
			} else {
				flags |= RTF_GATEWAY;
			}
		} else {
			flags &= ~RTF_GATEWAY;
		}
	}

	/**
	 * Set the up flag
	 * @param on
	 */
	public void setUp(boolean on) { 
		if (on) {
			flags |= RTF_UP;
		} else {
			flags &= ~RTF_UP;
		}
	}
	
	/**
	 * Gets the destination address of this route
	 */
	public IPv4Address getDestination() {
		return destination;
	}

	/**
	 * Gets the device of this route
	 */
	public Device getDevice() {
		return device;
	}

	/**
	 * Gets the NetDeviceAPI of the device of this route
	 */
	public NetDeviceAPI getDeviceAPI() {
		return deviceAPI;
	}

	/**
	 * Gets the netmask of the destination address
	 */
	public IPv4Address getSubnetmask() {
		return subnetmask;
	}

	/**
	 * Gets the gateway address. 
	 * @return The gateway address, or null is <code>isGateway</code> 
	 *   returns false
	 */
	public IPv4Address getGateway() {
		return gateway;
	}
	
	/**
	 * Convert to a String representation
	 * @see java.lang.Object#toString()
	 */
	public String toString() {
		final StringBuffer b = new StringBuffer();
		b.append(destination);
		b.append(" - ");
		b.append(subnetmask);
		b.append(" - ");
		b.append(gateway);
		b.append(" - ");
		if (isUp()) {
			b.append('U');
		}
		if (isGateway()) {
			b.append('G');
		}
		if (isHost()) {
			b.append('H');
		}
		b.append(" - ");
		b.append(useCount);
		b.append(" - ");
		b.append(device.getId());		
		return b.toString();
	}

	/**
	 * Gets the number of times this route has been used
	 */
	public int getUseCount() {
		return useCount;
	}

	/**
	 * Increment the number of times this route has been used
	 */
	public void incUseCount() {
		useCount++;
	}

}