使用jnetpcap库提取数据包详细信息

Question

如何使用jnetpcap库从脱机pcap文件中提取协议字段,源ip和目标ip？

Answer 1

对于TCP/IP堆栈:我们可以根据tcp头的端口号获取协议

对应于不同协议的端口号在以下链接中给出:http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml

在jnetpap库中获取协议(http://jnetpcap.com):

PcapPacket packet = //get from somewhere
Tcp tcp = new Tcp();
Ip4 ip = new IP4();
byte[] sIP = new byte[4];
byte[] dIP = new byte[4];
String sourceIP = "";
String destIP = "";

if(packet.hasHeader(ip) && packet.hasHeader(tcp)){
   sIP = packet.getHeader(ip).source();
   sourceIP = org.jnetpcap.packet.format.FormatUtils.ip(sIP);
   dIP = packet.getHeader(ip).destination();
   destIP = org.jnetpcap.packet.format.FormatUtils.ip(dIP);

   System.out.println("*" + sourceIP + "*" + destIP);
   System.out.println("Source IP" + sourceIP);
   System.out.println("Destination IP" + destIP);

   if(tcp.source() == 80){
      System.out.println("HTTP protocol");
   } else if(tcp.source == 23) {
      System.out.println("Telnet protocol");
   }
}