org.p2pvpn.tuntap.TunTap.java Source code

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Here is the source code for org.p2pvpn.tuntap.TunTap.java

Source

/*
Copyright 2008, 2009 Wolfgang Ginolas
    
This file is part of P2PVPN.
    
P2PVPN is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
Foobar is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.
    
You should have received a copy of the GNU Lesser General Public License
along with Foobar.  If not, see <http://www.gnu.org/licenses/>.
*/

package org.p2pvpn.tuntap;

import com.google.common.io.Resources;

import java.io.File;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * An apstract claas for an virtual network adapter. A different implementation
 * for every operating system is needed.
 * @author Wolfgang Ginolas
 */
public abstract class TunTap {

    private byte[] ip = null;

    /**
     * Load a libary (*.so or *.dll).
     * @param libs the libary names
     * @throws java.io.IOException
     */
    static void loadLib(String... libs) throws Throwable {
        Throwable e = null;

        for (String lib : libs) {
            try {
                String path = Resources.getResource(lib).getPath();
                System.out.println(path);
                System.load(Resources.getResource(lib).getPath());
                break;
            } catch (Throwable eio) {
                e = eio;
            }
        }
        if (e != null)
            throw e;
    }

    /*static void loadLibFromRecsource(String lib, String suffix) throws IOException {
       File tmp = File.createTempFile("lib", suffix);
       tmp.deleteOnExit();
       InputStream in = TunTap.class.getClassLoader().getResourceAsStream(lib);
       OutputStream out = new FileOutputStream(tmp);
        
       byte[] buffer = new byte[1024*8];
       int len;
        
       while (0<(len = in.read(buffer))) {
     out.write(buffer, 0, len);
       }
       in.close();
       out.close();
        
       System.load(tmp.getCanonicalPath());
    }*/

    /**
     * Return a TunTap object for the currently used operating system.
     * @return the TunTap object
     * @throws java.lang.Exception
     */
    static public TunTap createTunTap() throws Exception {
        String osName = System.getProperty("os.name");

        if (osName.startsWith("Windows")) {
            return new TunTapWindows();
        } else if (osName.equals("Linux")) {
            return new TunTapLinux();
        } else {
            throw new Exception("The operating system " + osName + " is not supported!");
        }
    }

    /**
     * @return the name of the virtuel network device
     */
    abstract public String getDev();

    /**
     * Close the device.
     */
    abstract public void close();

    /**
     * Send a packet to the virtual network adapter.
     * @param b the packet
     * @param len the length of the packet
     */
    abstract public void write(byte[] b, int len);

    /**
     * Read a packet from the virtual network adapter.
     * @param b the packet
     * @return length if the packet
     */
    abstract public int read(byte[] b);

    /**
     * Set the IP address of the virtual network adapter.
     * @param ip the IP
     * @param subnetmask the subnet mask
     */
    public void setIP(String ip, String subnetmask) {
        try {
            this.ip = InetAddress.getByName(ip).getAddress();
        } catch (UnknownHostException ex) {
        }
    }

    /**
     * Return the last set IP address.
     * @return the ip address
     */
    public byte[] getIPBytes() {
        return ip;
    }

}