Packet Sniffer in C#

hi, i also download it.but can't find myclasses....plz help me???

#define NULL 0

#define TCPDUMP_MAGIC 0xa1b2c3d4        /* Tcpdump Magic Number (Preamble)  */

#define PCAP_VERSION_MAJOR    2     /* Tcpdump Version Major (Preamble) */

#define PCAP_VERSION_MINOR    4     /* Tcpdump Version Minor (Preamble) */

#define DLT_NULL  0                           /* Data Link Type Null  */

#define DLT_EN10MB 1    /* Data Link Type for Ethernet II 100 MB and above */

#define DLT_EN3MB 2     /* Data Link Type for 3 Mb Experimental Ethernet */

// Ethernet Header

#define ETHER_ADDR_LEN 6

#include <stdio.h>

#include <iostream>

#include <fstream>

using namespace std;

FILE *input;

typedef struct packet_header

{

      unsigned int magic;                       /* Tcpdump Magic Number */

      unsigned short version_major;       /* Tcpdump Version Major */

      unsigned short version_minor;     /* Tcpdump Version Minor */

      unsigned int thiszone;                  /* GMT to Local Correction */

      unsigned int sigfigs;                   /* Accuracy of timestamps */

      unsigned int snaplen;         /* Max Length of Portion of Saved Packet */

      unsigned int linktype;                  /* Data Link Type */

} hdr;

typedef struct packet_timestamp

{

      unsigned int tv_sec;                   /* Timestamp in Seconds */

      unsigned int tv_usec;                   /* Timestamp in Micro Seconds */

      /* Total Length of Packet Portion (Ethernet Length until the End of Each Packet) */

      unsigned int caplen;

      unsigned int len;                 /* Length of the Packet (Off Wire) */

} tt;

typedef struct ether_header

{     unsigned char edst[ETHER_ADDR_LEN]; /* Ethernet Destination Address */

      unsigned char esrc[ETHER_ADDR_LEN];  /* Ethernet Source Address */

      unsigned short etype;                  /* Ethernet Protocol Type */

} eth;

int main(int argc, char *argv[])

{

      unsigned int remain_len = 0;

      unsigned char temp=0, hlen, version, tlen;

      int i, count=0;

      struct packet_header hdr;     /* Initialize Packet Header Structure */

      struct packet_timestamp tt;   /* Initialize Timestamp Structure */

      struct ether_header eth;      /* Initialize Ethernet Structure */

    unsigned char buff, array[1500];

      input = fopen("abc", "rb");         /* Open Input File */

      if(fopen == NULL)

            cout << "Cannot open saved windump file" << endl;

      else

      {

      /* Read & Display Packet Header Information */

            fread((char *) &hdr, sizeof(hdr), 1, input);               

            cout << "\n********** ********** PACKET HEADER ********** ***********" << endl;

            cout << "Preamble " << endl;

            cout << "Packet Header Length : " << sizeof(hdr) << endl;

            cout << " Magic Number : " << hdr.magic << endl;

            cout << "Version Major : " << hdr.version_major << endl;

            cout << "Version Minor : " << hdr.version_minor << endl;

            cout << "GMT to Local Correction : " << hdr.thiszone << endl;

            cout << "Jacked Packet with Length of : " << hdr.snaplen << endl;

            cout << "Accuracy to Timestamp   :  " << hdr.sigfigs  << endl;

            cout << "Data Link Type (Ethernet Type II = 1)  : " << hdr.linktype << endl;

            /* Use While Loop to Set the Packet Boundary */

            while(fread((char *) &tt, sizeof(tt), 1, input)) 

            /* Read & Display Timestamp Information */

            {

                  ++count;

                  cout << "********** ********** TIMESTAMP & ETHERNET FRAME ********** ***********" << endl;

                  cout << " Packet Number: " << count << endl;  /* Display Packet Number */

                  cout << " The Packets  are Captured in : " << tt.tv_sec << " Seconds" << endl;

                  cout << "The Packets  are Captured in : " << tt.tv_usec << " Micro-seconds" << endl;

                  /* Use caplen to Find the Remaining Data Segment */

                  cout << "The Actual Packet Length: " << tt.caplen << "Bytes" << endl; 

                  cout << "Packet Length (Off Wire): " << tt.len <<  "Bytes" << endl;

                  fread((char *) &eth, sizeof(eth), 1, input); /* Read & display ethernet header information */

                  cout << "Ethernet Header Length  : " << sizeof(eth) << " bytes" << endl;

                  // You may want to remove the  MAC Address output in your code

                  printf("MAC Destination Address     : [hex] %x :%x :%x :%x :%x :%x \n\t\t\t  [dec] %d :%d :%d :%d :%d :%d\n",

                        eth.edst[0], eth.edst[1],

                        eth.edst[2], eth.edst[3], eth.edst[4], eth.edst[5], eth.edst[0], eth.edst[1],

                        eth.edst[2], eth.edst[3], eth.edst[4], eth.edst[5], eth.edst[6]);

                  printf("MAC Source Address    : [hex] %x :%x :%x :%x :%x :%x \n\t\t\t  [dec] %d :%d :%d :%d :%d :%d\n",

                        eth.esrc[0], eth.esrc[1], eth.esrc[2],

                        eth.esrc[3], eth.esrc[4], eth.esrc[5], eth.esrc[0], eth.esrc[1],

                        eth.esrc[2], eth.esrc[3], eth.esrc[4], eth.esrc[5]);

                  printf("\n\n C Cout\n\n");

                  cout << "MAC Address " << eth.esrc[0] << " " << eth.esrc[1] << endl;

                  for (i=0;i<tt.caplen -14;i++)

                   { fread((char *) &buff, sizeof(buff), 1 , input);

                            printf(" %x", buff); // you may remove the printf line if neccessary

                            array[i] = buff;

             }

/*complete the code here

         Use the software  wireshark and capture a few packets from the live network and save the filename as abc.txt

and modify the program to display only TCP/IP packets, even modify further for the code to capture this packets from a live network. That it!!!!!

 */

             printf("\n ");

            } // end while

      } // end main else

      fclose(input); // Close input file

      return (0);

}