java抓包后对pcap文件解析示例

这是自己写的简单的解析pcap文件，方便读取pcap文件，大家参考使用吧

inputstream is = dataparser.class.getclassloader().getresourceasstream("baidu_cdr.pcap");

pcap pcap = pcapparser.unpack(is);
is.close();
byte[] t = pcap.getdata().get(0).getcontent();
byte[] data = arrays.copyofrange(t, 42, t.length);

pcapparser.java

package com.hylanda.pcap;

import java.io.ioexception;
import java.io.inputstream;
import java.util.arraylist;
import java.util.list;

/**
 * @author zhouqisheng
 *
 */
public class pcapparser {

 public static pcap unpack(inputstream is) throws ioexception {
  pcap pcap = null;
  byte[] buffer_4 = new byte[4];
  byte[] buffer_2 = new byte[2];
  pcap = new pcap();

  pcapheader header = new pcapheader();
  int m = is.read(buffer_4);
  if(m != 4){
   return null;
  }
  reversebytearray(buffer_4);
  header.setmagic(bytearraytoint(buffer_4, 0));
  m = is.read(buffer_2);
  reversebytearray(buffer_2);
  header.setmagor_version(bytearraytoshort(buffer_2, 0));
  m = is.read(buffer_2);
  reversebytearray(buffer_2);
  header.setminor_version(bytearraytoshort(buffer_2, 0));
  m = is.read(buffer_4);
  reversebytearray(buffer_4);
  header.settimezone(bytearraytoint(buffer_4, 0));
  m = is.read(buffer_4);
  reversebytearray(buffer_4);
  header.setsigflags(bytearraytoint(buffer_4, 0));
  m = is.read(buffer_4);
  reversebytearray(buffer_4);
  header.setsnaplen(bytearraytoint(buffer_4, 0));
  m = is.read(buffer_4);
  reversebytearray(buffer_4);
  header.setlinktype(bytearraytoint(buffer_4, 0));

  pcap.setheader(header);

  list<pcapdata> datalist = new arraylist<pcapdata>();
  while (m > 0) {
   pcapdata data = new pcapdata();
   m = is.read(buffer_4);
   if (m < 0) {
    break;
   }
   reversebytearray(buffer_4);
   data.settime_s(bytearraytoint(buffer_4, 0));
   m = is.read(buffer_4);
   reversebytearray(buffer_4);
   data.settime_ms(bytearraytoint(buffer_4, 0));
   m = is.read(buffer_4);
   reversebytearray(buffer_4);
   data.setplength(bytearraytoint(buffer_4, 0));
   m = is.read(buffer_4);
   reversebytearray(buffer_4);
   data.setlength(bytearraytoint(buffer_4, 0));
   byte[] content = new byte[data.getplength()];
   m = is.read(content);
   data.setcontent(content);

   datalist.add(data);
  }

  pcap.setdata(datalist);
  return pcap;
 }

 private static int bytearraytoint(byte[] b, int offset) {
  int value = 0;
  for (int i = 0; i < 4; i++) {
   int shift = (4 - 1 - i) * 8;
   value += (b[i + offset] & 0x000000ff) << shift;
  }
  return value;
 }

 private static short bytearraytoshort(byte[] b, int offset) {
  short value = 0;
  for (int i = 0; i < 2; i++) {
   int shift = (2 - 1 - i) * 8;
   value += (b[i + offset] & 0x000000ff) << shift;
  }
  return value;
 }

 /**
  * 反转数组
  * @param arr
  */
 private static void reversebytearray(byte[] arr){
  byte temp;
  int n = arr.length;
  for(int i=0; i<n/2; i++){
   temp = arr[i];
   arr[i] = arr[n-1-i];
   arr[n-1-i] = temp;
  }
 }

}

pcap.java

/**
 *
 */
package com.hylanda.pcap;

import java.util.list;

/**
 * @author zhouqisheng
 *
 */
public class pcap {
 private pcapheader header;
    private list<pcapdata> data;
 public pcapheader getheader() {
  return header;
 }
 public void setheader(pcapheader header) {
  this.header = header;
 }
 public list<pcapdata> getdata() {
  return data;
 }
 public void setdata(list<pcapdata> data) {
  this.data = data;
 }
    @override
    public string tostring(){
     stringbuilder s = new stringbuilder();
     s.append("header{\n");
     s.append(header.tostring());
     s.append("}\n");
     s.append("data part count=").append(data.size());

     return s.tostring();
    }
}

pcapdata.java

package com.hylanda.pcap;

/**
 * @author zhouqisheng
 *  数据包头
 */
public class pcapdata {
 private int time_s;//时间戳（秒）
 private int time_ms;//时间戳（微妙）
 private int plength;//抓包长度
 private int length;//实际长度
 private byte[] content;//数据
 public int gettime_s() {
  return time_s;
 }
 public void settime_s(int time_s) {
  this.time_s = time_s;
 }
 public int gettime_ms() {
  return time_ms;
 }
 public void settime_ms(int time_ms) {
  this.time_ms = time_ms;
 }
 public int getplength() {
  return plength;
 }
 public void setplength(int plength) {
  this.plength = plength;
 }
 public int getlength() {
  return length;
 }
 public void setlength(int length) {
  this.length = length;
 }
 public byte[] getcontent() {
  return content;
 }
 public void setcontent(byte[] content) {
  this.content = content;
 }

 @override
 public string tostring(){
  stringbuilder s = new stringbuilder();
  s.append("time_s=").append(this.time_s);
  s.append("\ntime_ms=").append(this.time_ms);
  s.append("\nplength=").append(this.plength);
  s.append("\nlength=").append(this.length);
  return null;
 }
}

pcapheader.java

package com.hylanda.pcap;

/**
 * @author zhouqisheng
 * pcap文件头
 */
public class pcapheader {
 private int magic;//文件识别头,为0xa1b2c3d4
 private short magor_version;//主要版本
    private short minor_version;//次要版本
    private int timezone;//当地标准时间
    private int sigflags;//时间戳的精度
    private int snaplen;//最大的存储长度
    /**
     * 0            bsd loopback devices, except for later openbsd
  1            ethernet, and linux loopback devices
  6            802.5 token ring
  7            arcnet
  8            slip
  9            ppp
  10           fddi
  100         llc/snap-encapsulated atm
  101         “raw ip”, with no link
  102         bsd/os slip
  103         bsd/os ppp
  104         cisco hdlc
  105         802.11
  108         later openbsd loopback devices (with the af_value in network byte order)
  113         special linux “cooked” capture
  114         localtalk
     */
    private int linktype;//链路类型
 public int getmagic() {
  return magic;
 }
 public void setmagic(int magic) {
  this.magic = magic;
 }
 public short getmagor_version() {
  return magor_version;
 }
 public void setmagor_version(short magor_version) {
  this.magor_version = magor_version;
 }
 public short getminor_version() {
  return minor_version;
 }
 public void setminor_version(short minor_version) {
  this.minor_version = minor_version;
 }
 public int gettimezone() {
  return timezone;
 }
 public void settimezone(int timezone) {
  this.timezone = timezone;
 }
 public int getsigflags() {
  return sigflags;
 }
 public void setsigflags(int sigflags) {
  this.sigflags = sigflags;
 }
 public int getsnaplen() {
  return snaplen;
 }
 public void setsnaplen(int snaplen) {
  this.snaplen = snaplen;
 }
 public int getlinktype() {
  return linktype;
 }
 public void setlinktype(int linktype) {
  this.linktype = linktype;
 }

 @override
    public string tostring(){
  stringbuilder s = new stringbuilder();
  s.append("magic=").append("0x" + integer.tohexstring(this.magic));
  s.append("\nmagor_version=").append(this.magor_version);
  s.append("\nminor_version=").append(this.minor_version);
  s.append("\ntimezone=").append(this.timezone);
  s.append("\nsigflags=").append(this.sigflags);
  s.append("\nsnaplen=").append(this.snaplen);
  s.append("\nlinktype=").append(this.linktype);
     return s.tostring();
    }
}