November 2008

Version 1.2 RC1 is released and I have not heard of any issues from the initial testers. It does usually take a few days before I get any feedback.

There were a few things that did not make it in RC1 but need to be included in the general 1.2 release. Mainly the existing protocol headers need to be fixed up and completed.

I'm keeping track of these omissions and bugs here:
https://sourceforge.net/tracker2/?func=browse&group_id=164277&atid=83108...

Main thing that was left out, because of time pressure, was protocol sub headers. That is things like Ip options which are optional headers. I'm working on adding them in. Very small changes to the formatter package basically added another public format method that takes 2 JHeaders as argument, 1st the parent and second the sub-header. And Text and Xml subclasses just needed to implement 2 new abstract methods, beforeSubHeader and afterSubHeader. All they do is properly setup the indent levels and print out nice summary of the sub header i.e. ("ip4: ******* ip4 optional header (timestamp)"). Xml formatter was even simpler. All they do is call on existing header formatting methods at increased indent level.

Also I'm completing the protocol header implementations. Like I said, Ip and the Tcp protocols don't have their options defined in RC1. Also ICMP definition is incomplete, so I need to just add in all the ICMP cases and that will be it for RC2.

So RC2 is definitely coming after I get these last few tidbits in. Of course any bugs that come up will be fixed very quickly as well.

I'd appreciate any feedback about any bugs or API issues (anything clumsy for example.)

Q: I get this exception when I try to access any methods from org.jnetpcap.winpcap package.

A: The exception is telling you that on this particular platform the winpcap extension is not available and can not be used.

WinPcap native library is a windows implementation of libpcap library. It supports all of the libpcap functions and adds several new capabilities but only on windows platforms. jNetPcap API provides WinPcap extention only on windows platform.

In order to avoid having this error thrown, the user must check if WinPcap extension is supported on this particular platform at runtime. To check for support use WinPcap.isSupported():boolean method which will return a boolean true if it is supported, otherwise false. This method never throws an exception and needs to be used before your code relies on any features within that winpcap package.

Get interface's hardware address (MAC address)

This example gets a list of interfaces then iterates through the list. For each interface it acquires MAC address, formats it and prints it out. The example skips any interfaces that do not have a MAC address assigned such as loop interfaces non datalink interfaces.

Source code: GetInterfaceHardwareAddress.java

package org.jnetpcap.examples;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.jnetpcap.Pcap;
import org.jnetpcap.PcapIf;

public class GetInterfaceHardwareAddress {

  public static void main(String[] args) throws IOException {

    List<PcapIf> alldevs = new ArrayList<PcapIf>(); // Will be filled with NICs
    StringBuilder errbuf = new StringBuilder(); // For any error msgs

    /***************************************************************************
     * First get a list of devices on this system
     **************************************************************************/
    int r = Pcap.findAllDevs(alldevs, errbuf);
    if (r == Pcap.NOT_OK || alldevs.isEmpty()) {
      System.err.printf("Can't read list of devices, error is %s", errbuf
        .toString());
      return;
    }

    /***************************************************************************
     * Second iterate through all the interface and get the HW addresses
     **************************************************************************/
    for (final PcapIf i : alldevs) {
      final byte[] mac = i.getHardwareAddress();
      if (mac == null) {
        continue; // Interface doesn't have a hardware address
      }
      System.out.printf("%s=%s\n", i.getName(), asString(mac));
    }
  }

  private static String asString(final byte[] mac) {

Here is a large jUnit test case that shows off numerous capabilities of jNetPcap:

package org.jnetpcap;

import java.io.File;
import java.io.IOException;
import java.net.SocketException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

import junit.framework.TestCase;
import junit.textui.TestRunner;

import org.jnetpcap.nio.JBuffer;
import org.jnetpcap.nio.JMemory;
import org.jnetpcap.nio.JNumber;
import org.jnetpcap.nio.JNumber.Type;

/**
 * @author Mark Bednarczyk
 * @author Sly Technologies, Inc.
 */
@SuppressWarnings("deprecation")
public class TestPcapJNI
    extends TestCase {

	// private final static String device =
	// "\\Device\\NPF_{BC81C4FC-242F-4F1C-9DAD-EA9523CC992D}";

	private final static String win =
	    "\\Device\\NPF_{BC81C4FC-242F-4F1C-9DAD-EA9523CC992D}";

	private final static String linux = "any";

	private final static boolean isWindows =
	    "Windows XP".equals(System.getProperty("os.name"));

	private final static String device = (isWindows) ? win : linux;

	private final static String fname = "tests/test-l2tp.pcap";

	private static final int OK = 0;

	private static final int snaplen = 64 * 1024;

	private static final int promisc = 1;

	private static final int oneSecond = 1000;

	/**
	 * Will generate HTTP traffic to a website. Use start() to start in a test
	 * method, and always put stop() in tearDown. Safe to call stop even when
	 * never started.
	 */
	private static final HttpTrafficGenerator gen = new HttpTrafficGenerator();

	private static File tmpFile;

	static {
		try {
			tmpFile = File.createTempFile("temp-", "-TestPcapJNI");
		} catch (IOException e) {
			tmpFile = null;
			System.err.println("Unable to initialize a temporary file");
		}

	}

	private StringBuilder errbuf = new StringBuilder();

	private final PcapHandler<?> doNothingHandler = new PcapHandler