JpcapSender.java

package jpcap;

import jpcap.packet.Packet;

/**
 * This class is used to send a packet.
 */
public class JpcapSender extends JpcapInstance
{
	private native String nativeOpenDevice(String device);

	private native void nativeSendPacket(Packet packet);

	private native void nativeCloseDevice();

	private native void nativeOpenRawSocket();

	private native void nativeSendPacketViaRawSocket(Packet packet);

	private native void nativeCloseRawSocket();

	private static final int RAW_SOCKET_ID = 99999;

	private JpcapSender() throws java.io.IOException
	{
		if(reserveID() < 0)
		{
			throw new java.io.IOException("Unable to open a device: " + MAX_NUMBER_OF_INSTANCE + " devices are already opened.");
		}
	}

	JpcapSender(int ID)
	{
		this.ID = ID;
	}

	/**
	 * Initializes a network interface for sending a packet, and returns an
	 * instance of this class.
	 *
	 * @param device Interface for sending a packet
	 * @return intstance of this class (JpcapSender)
	 * @throws IOException Raised when initialization of the interface failed
	 */
	public static JpcapSender openDevice(NetworkInterface device) throws java.io.IOException
	{
		JpcapSender sender = new JpcapSender();
		String ret = sender.nativeOpenDevice(device.name);

		if(ret == null)
		{
			return sender;
		}
		else
		{
			throw new java.io.IOException(ret);
		}
	}

	/**
	 * Open a raw IP socket to send a packet.<BR>
	 * When sending a packet via a raw socket, the datalink header of the packet is ignored
	 * (= automatically generated by OS).<P>
	 * Note: the implementation and behavior of a raw socket may vary in different OS.
	 * Also, you can only open one raw socket at a time.
	 *
	 * @return intstance of this class (JpcapSender)
	 * @throws IOException Raised when initialization of the interface failed
	 */
	@Deprecated
	public static JpcapSender openRawSocket() throws java.io.IOException
	{
		JpcapSender sender = new JpcapSender();
		sender.nativeOpenRawSocket();
		sender.ID = RAW_SOCKET_ID;

		return sender;
	}

	/**
	 * Closes the interface.
	 */
	public void close()
	{
		if(ID == RAW_SOCKET_ID)
		{
			nativeCloseRawSocket();
		}
		else
		{
			nativeCloseDevice();
		}
		unreserveID();
	}

	/**
	 * Sends a packet.
	 * <p/>
	 * If this JpcapSender instance was created by openDevice(), you need to set
	 * the Datalink layer's header (e.g., Ethernet header) of the packet. <P>
	 * <p/>
	 * If this JpcapSender instance was created by openRawSocket(), you can only
	 * send IP packets, but you may not need to set the Datalink layer's header
	 * of the IP packets you want to send.<BR>
	 * Note: the implementation and behavior of a raw socket may vary in different OS.
	 * For example, in Windows 2000/XP, you need to manually set the datalink/IP headers
	 * of a packet.
	 *
	 * @param packet Packet to be sent
	 */
	public void sendPacket(Packet packet)
	{
		if(ID == RAW_SOCKET_ID)
		{
			nativeSendPacketViaRawSocket(packet);
		}
		else
		{
			nativeSendPacket(packet);
		}
	}
}