无法使用JPCAP打开设备

Question

我在使用JPCAP库打开网络设备时遇到麻烦。我已经在System32和Syswow64中安装了WinPCAP并具有JPCAP.DLL。尝试打开设备时，以下教程代码崩溃。碰撞日志：

PacketCapture: loading native library jpcap.. ok
net.sourceforge.jpcap.capture.CaptureDeviceOpenException: Error opening adapter: The system cannot find the device specified. (20)
    at net.sourceforge.jpcap.capture.PacketCapture.open(Native Method)
    at net.sourceforge.jpcap.capture.PacketCapture.open(PacketCapture.java:57)
    at networksnifferdesktop.NetworkSnifferDesktop.<init>(NetworkSnifferDesktop.java:26)
    at networksnifferdesktop.NetworkSnifferDesktop.main(NetworkSnifferDesktop.java:40)
Java Result: 1

在调试中，我可以看到m_device设置为：

"DeviceNPF_{EC5226CF-3F55-4148-B40E-1FC3F8BB3398}   Realtek PCIe GBE Family Controller"

在以下代码中：

package networksnifferdesktop;
import net.sourceforge.jpcap.capture.*;
import net.sourceforge.jpcap.net.*;
public class NetworkSnifferDesktop
{
    private static final int INFINITE = -1;
    private static final int PACKET_COUNT = 10;
    // BPF filter for capturing any packet
    private static final String FILTER = "";
    private PacketCapture m_pcap;
    private String m_device;
    public NetworkSnifferDesktop() throws Exception
    {
        // Step 1:  Instantiate Capturing Engine
        m_pcap = new PacketCapture();
        // Step 2:  Check for devices
        m_device = m_pcap.findDevice();
        // Step 3:  Open Device for Capturing (requires root)
        m_pcap.open(m_device, true);
        // Step 4:  Add a BPF Filter (see tcpdump documentation)
        m_pcap.setFilter(FILTER, true);
        // Step 5:  Register a Listener for Raw Packets
        m_pcap.addRawPacketListener(new RawPacketHandler());
        // Step 6:  Capture Data (max. PACKET_COUNT packets)
        m_pcap.capture(PACKET_COUNT);
    }
    public static void main(String[] args)
    {
        try
        {
            NetworkSnifferDesktop example = new NetworkSnifferDesktop();
        }
        catch (Exception e)
        {
            e.printStackTrace();
            System.exit(1);
        }
    }
}
class RawPacketHandler implements RawPacketListener
{
    private static int m_counter = 0;
    public void rawPacketArrived(RawPacket data)
    {
        m_counter++;
        System.out.println("Received packet (" + m_counter + ")");
    }
}

Answer 1

"DeviceNPF_{EC5226CF-3F55-4148-B40E-1FC3F8BB3398} Realtek PCIe GBE Family Controller"，如果您的字符串含义为一个字符串，其第一个字符是" device"中的" d"，其最后一个字符是"控制器"中的" r"，IS 不是有效的winpcap设备名称字符串。

"DeviceNPF_{EC5226CF-3F55-4148-B40E-1FC3F8BB3398}"将是有效的设备名称字符串。

通过查看JPCAP源，findDevice方法似乎不是返回有效的设备名称字符串。它被记录为返回"描述网络设备的字符串"；它返回的是一个包含设备名称字符串，newline，两个空白和设备供应商描述字符串的字符串。据报道这是JPCAP错误。

我建议您扫描字符串，寻找第一个白色空间字符（"白空间"包含空白和新线），然后用作设备名称，可以传递到打开的例程，但所有内容都无法包括那个白色空间的角色。（如果您找不到白色空间字符，请使用整个字符串。）