Hi there,
well, i have homework of packet sniffing software
i'm not suppose to write the code,but i need to make a report of an existing code and explain it in details.
I found the following code somewhere(the code should be of a packet sniffer) ,but i couldn't run it.I tried over and over and get no result
I used microsoft c++ 2008 to run it in windows platform.
Can anybody tell me why i couldn't run the code?
// File.cpp
#include "header.h"
#include <iostream>
using namespace std;
/* open raw socket, set promiscuous mode */
void init_net() {
WSADATA w;
SOCKADDR_IN sa;
DWORD bytes;
char hostname[HOSTNAME_LEN];
struct hostent *h;
unsigned int opt = 1;
if (WSAStartup(MAKEWORD(2,2), &w) != 0)
die("WSAStartup failed\n");
if ((s0k = socket(AF_INET, SOCK_RAW, IPPROTO_IP)) == INVALID_SOCKET)
die("unable to open raw socket\n");
// use default interface
if ((gethostname(hostname, HOSTNAME_LEN)) == SOCKET_ERROR)
die("unable to gethostname\n");
if ((h = gethostbyname(hostname)) == NULL)
die("unable to gethostbyname\n");
sa.sin_family = AF_INET;
sa.sin_port = htons(6000);
memcpy(&sa.sin_addr.S_un.S_addr, h->h_addr_list[0], h->h_length);
if ((bind(s0k, (SOCKADDR *)&sa, sizeof(sa))) == SOCKET_ERROR)
die("unable to bind() socket\n");
if (promiscuous) /* -d on the command line to disable promiscuous mode */
if ((WSAIoctl(s0k, SIO_RCVALL, &opt, sizeof(opt), NULL, 0, &bytes, NULL, NULL)) == SOCKET_ERROR)
die("failed to set promiscuous mode\n");
}
void main() {
char pak[PAKSIZE];
DWORD bytes;
init_net();
WriteData( "Program has started: " );
WriteData( "\r\n\r\n" );
while(1)
{
memset(pak, 0, sizeof(pak));
if ((bytes = recv(s0k, pak, sizeof(pak), 0)) == SOCKET_ERROR)
{
die("socket error on recv\n");
}else{
process_pak(pak, bytes);
}
}
}
void WriteData( const char* buffer )
{
FILE * pFile;
pFile = fopen( "./File1.txt", "a" );
printf( buffer );
fprintf( pFile, buffer );
fclose( pFile );
}
/* parse pak, print out requested fields */
void process_pak(char *pak, int len) {
struct iphdr *ip;
struct tcphdr *tcp;
char *data;
unsigned char proto; /* to avoid repeated dereferencing */
int i, j, k, end, datasize;
ip = (struct iphdr *) pak;
proto = ip->proto;
printf("Prototype: %i\n", (unsigned char)proto);
if(proto == IPPROTO_TCP)
{
tcp = (struct tcphdr *) (pak + (ip->ihl * 4));
data = pak + (ip->ihl * 4) + (tcp->tcphl * 4);
datasize = ntohs(ip->totlen) - (ip->ihl*4) - (tcp->tcphl*4);
/* ==================================== */
/* START CONTROLE FUNCTIE */
/* ==================================== */
i = 0;
// If the packet size is smaller than the required size, just trow it away!
// if( datasize < minSize )
// {
// return;
// }
char temp[50];
sprintf(temp, "New Package: %x %x %x %x", data[0], data[1], data[2], data[3]);
WriteData( temp );
WriteData("\r\n");
printf("DataSize: %i\r\n", datasize);
// Print all data to the file.
for(j=0; j<datasize; j++)
{
char temp [10];
sprintf(temp, "%4i", data[j]);
WriteData( temp );
i = (i+1);
if(i==4){ WriteData(" "); }
if(i==8) { WriteData(" "); }
if(i==12){ WriteData(" "); }
if(i==16) {
WriteData(" -> ");
i=0;
for(k=(j-15); k<(j+1); k++)
{
char temp [10];
sprintf(temp, "%1c", data[k]);
if(data[k] < 32)
{
sprintf(temp, "%1c", '.');
}
WriteData( temp );
i = (i+1);
if(i==8) { WriteData(" "); }
}
WriteData("\r\n"); i=0;
}
}
if(i > 0)
WriteData("\r\n");
WriteData("\r\n");
}else{
// No TCP protocol: return and don't waist any time!
return;
} }
void bind_to_interface(int choice) {
SOCKET sd;
sd = WSASocket(AF_INET, SOCK_DGRAM, 0, 0, 0, 0);
if (sd == SOCKET_ERROR)
printf("error on WSASocket\n");
INTERFACE_INFO InterfaceList[20];
unsigned long nBytesReturned;
if (WSAIoctl(sd, SIO_GET_INTERFACE_LIST, 0, 0, &InterfaceList, sizeof(InterfaceList), &nBytesReturned, 0, 0) == SOCKET_ERROR) {
printf("error fetching interface list\n");
}
int nNumInterfaces = nBytesReturned / sizeof(INTERFACE_INFO);
if (choice > nNumInterfaces) {
die("invalid interface selection\n");
}
if (choice) {
// bind to the specified interface and return
SOCKADDR_IN *pAddress;
pAddress = (SOCKADDR_IN *) & (InterfaceList[choice-1].iiAddress);
printf("using interface: %s\n", inet_ntoa(pAddress->sin_addr));
if ((bind(s0k, (SOCKADDR *)&(InterfaceList[choice-1].iiAddress), sizeof(SOCKADDR_IN))) == SOCKET_ERROR)
die("unable to bind() socket\n");
return;
} }
void die(char *s) {
WSACleanup();
WriteData( "%s" );
exit(-1);
}// header.h
#pragma com
ment(lib, "ws2_32.lib")
#include <winsock2.h>
#include <stdio.h>
#include <string.h>
#include <windows.h>
#include <ws2tcpip.h>
#include <time.h>
/* packet header structures */
#pragma pack(push, 1)
struct iphdr {
unsigned char ihl:4;
unsigned char ver:4;
unsigned char tos;
unsigned short totlen;
unsigned short id;
unsigned short frag_and_flags;
unsigned char ttl;
unsigned char proto;
unsigned short checksum;
unsigned int src;
unsigned int dst;
};
struct tcphdr {
unsigned short sport;
unsigned short dport;
unsigned int seq;
unsigned int acknum;
unsigned char unused:4;
unsigned char tcphl:4;
unsigned char Flags;
unsigned short Windows;
unsigned short cksum;
unsigned short UrgPointer;
};
#pragma pack(pop)
#define HOSTNAME_LEN 1024
#define SIO_RCVALL _WSAIOW(IOC_VENDOR,1)
#define PAKSIZE 65536
void init_opt(int, char **);
void init_net(void);
void die(char *);
void process_pak(char *, int);
void bind_to_interface(int);
void WriteData( const char* );
/* G L O B A L S */
SOCKET s0k;
short promiscuous=1;I don't say i understand the code perfectly,but i need to make sure i can run it before start studying it.
thanks in advance