我從這裏有這個代碼 https://javatutorial.net/capture-network-packages-java 但它不會返回src或目標ips。我可以看到通過JNetPcap捕獲包沒有IP返回
System.out.println("packet.getHeader(ip)");
System.out.println(packet.getHeader(ip));
IP中的IP:******* IP4 - 「IP版本4」 - 偏移量= 14(0xE)長度= 20協議套件= NETWORK
葉:
葉:版本= 4
葉:爲hLen = 5 [5 * 4 = 20個字節,沒有IP選項]
葉:區分服務爲0x0 =(0)
Ip:0000 00 .. = [0]代碼點:未設置
Ip:.... ..0。 = [0] ECN位:未設置
葉:.... ... 0 = [0] ECE位:未設置
葉:長度= 137
葉:ID = 0xC22C (49708)
葉:標誌= 0×2(2)
葉:0 .. = [0]保留
葉:0.1。 = [1] DF:不片段:設置
葉:..0 = [0] MF:多個片段:未設置
葉:偏移量= 0
葉:TTL = 62 [生存時間]
葉:式= 6下一個[:傳輸控制]
葉:校驗= 0xF22E(61998)[正確]
葉:源= 10.222.82.222
葉:目的地= 10.222.82.224
葉:
我在做什麼錯?
`import java.util.ArrayList;
import java.util.List;
import org.jnetpcap.Pcap;
import org.jnetpcap.PcapIf;
import org.jnetpcap.packet.PcapPacket;
import org.jnetpcap.packet.PcapPacketHandler;
import org.jnetpcap.protocol.network.Ip4;
public class PackageCapture {
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
int r = Pcap.findAllDevs(alldevs, errbuf);
if (r != Pcap.OK || alldevs.isEmpty()) {
System.err.printf("Can't read list of devices, error is %s",
errbuf.toString());
return;
}
System.out.println("Network devices found:");
int i = 0;
for (PcapIf device : alldevs) {
String description = (device.getDescription() != null) ? device
.getDescription() : "No description available";
System.out.printf("#%d: %s [%s]\n", i++, device.getName(),
description);
}
PcapIf device = alldevs.get(0); // Get first device in list
System.out.printf("\nChoosing '%s' on your behalf:\n",
(device.getDescription() != null) ? device.getDescription()
: device.getName());
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
Pcap pcap = Pcap.openLive(device.getName(), snaplen, flags, timeout, errbuf);
if (pcap == null) {
System.err.printf("Error while opening device for capture: "
+ errbuf.toString());
return;
}
PcapPacketHandler<String> jpacketHandler = new PcapPacketHandler<String>() {
public void nextPacket(PcapPacket packet, String user) {
byte[] data = packet.getByteArray(0, packet.size()); // the package data
byte[] sIP = new byte[4];
byte[] dIP = new byte[4];
Ip4 ip = new Ip4();
if (packet.hasHeader(ip) == false) {
return; // Not IP packet
}
ip.source(sIP);
ip.destination(dIP);
/* Use jNetPcap format utilities */
String sourceIP =
org.jnetpcap.packet.format.FormatUtils.ip(sIP);
String destinationIP =
org.jnetpcap.packet.format.FormatUtils.ip(dIP);
System.out.println("srcIP=" + sourceIP +
" dstIP=" + destinationIP +
" caplen=" + packet.getCaptureHeader().caplen());
}
};
// capture first 10 packages
pcap.loop(10, jpacketHandler, "jNetPcap");
pcap.close();
}
}`