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#include <iostream>
#include <fstream>
#include <iomanip>
#include <cctype>
#include <vector>
using namespace std;
struct s_header {
unsigned char verCode;
unsigned char serviceType;
unsigned short totLength;
unsigned char reserved;
unsigned char flags;
unsigned short hopCount;
unsigned char srcAddr0;
unsigned char srcAddr1;
unsigned char srcAddr2;
unsigned char srcAddr3;
unsigned char destAddr0;
unsigned char destAddr1;
unsigned char destAddr2;
unsigned char destAddr3;
} header;
char * codes[] = {
"OK",
"Possible data corruption"
};
char * services[] = {
"Normal",
"Low Priority",
"High Priority",
"Medium Priority",
"So-so Priority",
"Needed Yesterday",
"Nevermind"
};
char * flags[] = {
"Grumpy",
"Sneezy",
"Bashful",
"Doc",
"Dopey",
"Tipsy",
"Surly",
"Snow White"
};
int main(int argc, char * argv)
{
const char* const file_name = "PACKETS.txt";
int x;
char ch;
ifstream file(file_name, ios::in | ios::binary); // open for input in binary mode
if (!file.is_open())
{
std::cerr << "failed to open file\n";
return 1;
}
do
{
s_header header; //create object of s_header struct
const auto hdr_size = sizeof(header); //get size of header file
if (file.read(reinterpret_cast<char*>(std::addressof(header)), hdr_size) &&
file.gcount() == hdr_size)
{
// print out contents of header in a readable form, not needed here...
const auto idata_size = header.totLength - 16;
vector<char> buffer(idata_size);
if (file.read(buffer.data(), buffer.size()) && file.gcount() == idata_size)
{
// display data from header
cout << "Version:" << setw(9) << (header.verCode >> 4) << endl;
cout << "Code:" << setw(12) << (header.verCode & 0x0F) << " - " << codes[(header.verCode & 0x0f)] << endl;
cout << "Total Length:" << setw(5) << header.totLength << endl;
cout << "Service Type:" << setw(4) << (int)header.serviceType << " - " << services[header.serviceType] << endl;
//display flags using a mask and loop
x = header.flags;
for (int i = 0; i < 8; i++)
{
cout << " " << flags[i] << ":\t" << (x & 1) << endl;
x = x >> 1;
}
cout << "Hop Count:" << setw(8) << header.hopCount << endl;
cout << "Source Address:" << setw(4) << (int)header.srcAddr0 << "." << (int)header.srcAddr1 << "." << (int)header.srcAddr2
<< "." << (int)header.srcAddr3 << endl;
cout << "Dest Address:" << setw(4) << (int)header.destAddr0 << "." << (int)header.destAddr1 << "." << (int)header.destAddr2
<< "." << (int)header.destAddr3 << endl;
cout << "Data:" << endl;
for (int i = 0; i < idata_size; i++)
{
cout << (char)buffer[i];
}
}
else
{
cerr << "failed to read data\n";
return 1;
}
}
else
{
std::cerr << "failed to read header\n";
return 1;
}
cout << ("Read in next packet? Y/N ");
ch = getchar();
cout << "\n" << endl;
} while (ch == 'Y' || ch == 'y');
//cout << endl;
system("pause");
}
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