Send Queue

WinPcap Send Queue Transmit

Download source from SVN: Send Queue Transmit on Win32 platform Example

package org.jnetpcap.examples;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.jnetpcap.Pcap;
import org.jnetpcap.PcapIf;
import org.jnetpcap.PcapPktHdr;
import org.jnetpcap.winpcap.WinPcap;
import org.jnetpcap.winpcap.WinPcapSendQueue;

public class WinPcapSendQueueTransmitExample {
  public static void main(String[] args) {
    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;
    }
    PcapIf device = alldevs.get(0); // We know we have atleast 1 device

    /***************************************************************************
     * Second we open a network interface
     **************************************************************************/
    int snaplen = 64 * 1024; // Capture all packets, no trucation
    int flags = Pcap.MODE_PROMISCUOUS; // capture all packets
    int timeout = 10 * 1000; // 10 seconds in millis
    WinPcap pcap = WinPcap.openLive(device.getName(), snaplen, flags, timeout, errbuf);

    /***************************************************************************
     * Third we create our crude packet queue we will transmit out 
     * This creates a small queue full of broadcast packets
     **************************************************************************/
    WinPcapSendQueue queue = WinPcap.sendQueueAlloc(512);
    PcapPktHdr hdr = new PcapPktHdr(128, 128);
    byte[] pkt = new byte[128];
		
    Arrays.fill(pkt, (byte) 255); // Broadcast
    queue.queue(hdr, pkt); // Packet #1
    queue.queue(hdr, pkt); // Packet #2

    Arrays.fill(pkt, (byte) 0x11); // Junk packet
    queue.queue(hdr, pkt); // Packet #3

    /***************************************************************************
     * Fourth We send our packet off using open device
     **************************************************************************/
    r = pcap.sendQueueTransmit(queue, WinPcap.TRANSMIT_SYNCH_ASAP);
    if (r != queue.getLen()) {
      System.err.println(pcap.getErr());
      return;
    }
    /***************************************************************************
     * Lastly we close
     **************************************************************************/
    pcap.close();
  }
}