pcap4j+winpcap我应该手动运行rpcapd.exe吗

Question

嗨，我已经手动下载了pcap4j和winpcap以及所有jar(jna，pcap4j-core-1.8.2，slf4j-api-1.7.25，slf4j-simple-1.7.25(依赖项。添加到项目中，所有编译都很好。但是：当我开始嗅探数据包时。getHeader((和数据包。getPayload((返回null！如果我手动运行rpcapd.exe，那么它可以工作。。。为什么？

package sniffer;
import java.io.IOException;
import org.pcap4j.core.BpfProgram.BpfCompileMode;
import org.pcap4j.core.NotOpenException;
import org.pcap4j.core.PacketListener;
import org.pcap4j.core.PcapHandle;
import org.pcap4j.core.PcapNativeException;
import org.pcap4j.core.PcapNetworkInterface;
import org.pcap4j.core.PcapNetworkInterface.PromiscuousMode;
import org.pcap4j.packet.Packet;
import org.pcap4j.util.NifSelector;
public class App {
static PcapNetworkInterface getNetworkDevice() {
PcapNetworkInterface device = null;
try {
device = new NifSelector().selectNetworkInterface();
} catch (IOException e) {
e.printStackTrace();
}
return device;
}
public static void main(String[] args) throws PcapNativeException, NotOpenException {
// The code we had before
PcapNetworkInterface device = getNetworkDevice();
System.out.println("You chose: " + device);
// New code below here
if (device == null) {
System.out.println("No device chosen.");
System.exit(1);
}
// Open the device and get a handle
int snapshotLength = 65536; // in bytes   
int readTimeout = 50; // in milliseconds                   
final PcapHandle handle;
handle = device.openLive(snapshotLength, PromiscuousMode.PROMISCUOUS, readTimeout);
String filter = "tcp port 80";
handle.setFilter(filter, BpfCompileMode.OPTIMIZE);
// Create a listener that defines what to do with the received packets
PacketListener listener = new PacketListener() {
@Override
public void gotPacket(Packet packet) {
// Override the default gotPacket() function and process packet
System.out.println(handle.getTimestamp());
System.out.println(packet);
System.out.println(packet.getHeader());///////////////<<<<<<<<<<<------------
}
};
// Tell the handle to loop using the listener we created
try {
int maxPackets = 50;
handle.loop(maxPackets, listener);
} catch (InterruptedException e) {
e.printStackTrace();
}
// Cleanup when complete
handle.close();
}
}

Answer 1

您需要在类路径中添加一个数据包工厂(例如pcap4j packetfactory static.jar(，或者pcap4j为所有数据包创建UnknownPacket实例，其中getPayload((和getHeader((返回null。