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#include <pcap.h>
#include <Tchar.h>
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h>
using namespace std;
//Ethernet Header
typedef struct ether_header {
unsigned char ether_dhost[6]; // destination
unsigned char ether_shost[6]; // source
unsigned short ether_type;
}ETHHEADER,*PETHHEADER;
//IPv4 Header
typedef struct ip_header {
unsigned char ver_ihl; // version
unsigned char tos; // type of service
unsigned short tlen; // total lenght
unsigned short identification;
unsigned short flags_fo; // Flags
unsigned char ttl; // time to live
unsigned char proto; // protocol
unsigned char crc; // checksum
u_char ip_src[4]; // source IP
u_char ip_dst[4]; // destination IP
}IPHEADER,*PIPHEADER;
// TCP Header
typedef struct tcp_header {
WORD sourceport; // source port
WORD destport; // destination port
DWORD seqno; // sequenz number
DWORD ackno; // acknowledge number
BYTE hlen; // Header length
BYTE flag; // flags
WORD window; // window
WORD chksum; // checksum
WORD urgptr; // urgend pointer
}TCPHEADER,*PTCPHEADER;
int _tmain(int argc, _TCHAR* argv[])
{
pcap_if_t * allAdapters;
pcap_if_t * adapter;
pcap_t * adapterHandle;
struct pcap_pkthdr * packetHeader;
const u_char * packetData;
char errorBuffer[ PCAP_ERRBUF_SIZE ];
unsigned int netmask = 0xffffff; // netmask to recieve from all IPs
char packet_filter[] = "tcp port 5055"; // Filter set to Port 5055 for SCIP
struct bpf_program fcode;
//--------------------------------------------------------------------------
// retrieve the adapters from the computer
// you can choose which adapter you want to use
// also Filter for Port 5055 (can be changed above) is set here, to keep traffic as low as possible
if( pcap_findalldevs_ex( PCAP_SRC_IF_STRING, NULL,
&allAdapters, errorBuffer ) == -1 )
{
fprintf( stderr, "Error in pcap_findalldevs_ex function: %s\n", errorBuffer );
return -1;
}
// if there are no adapters, print an error
if( allAdapters == NULL )
{
printf( "\nNo adapters found! Make sure WinPcap is installed.\n" );
return 0;
}
// print the list of adapters along with basic information about an adapter
int crtAdapter = 0;
for( adapter = allAdapters; adapter != NULL; adapter = adapter->next)
{
printf( "\n%d.%s ", ++crtAdapter, adapter->name );
printf( "-- %s\n", adapter->description );
}
printf( "\n" );
int adapterNumber;
printf( "Enter the adapter number between 1 and %d:", crtAdapter );
scanf_s( "%d", &adapterNumber );
if( adapterNumber < 1 || adapterNumber > crtAdapter )
{
printf( "\nAdapter number out of range.\n" );
// Free the adapter list
pcap_freealldevs( allAdapters );
return -1;
}
// parse the list until we reach the desired adapter
adapter = allAdapters;
for( crtAdapter = 0; crtAdapter < adapterNumber - 1; crtAdapter++ )
adapter = adapter->next;
// open the adapter with promiscous mode enabled
adapterHandle = pcap_open( adapter->name, // name of the adapter
65536, // portion of the packet to capture
// 65536 guarantees that the whole
// packet will be captured
PCAP_OPENFLAG_PROMISCUOUS, // promiscuous mode
1000, // read timeout - 1 millisecond
NULL, // authentication on the remote machine
errorBuffer // error buffer
);
if( adapterHandle == NULL )
{
fprintf( stderr, "\nUnable to open the adapter\n", adapter->name );
// compile the filter
if (pcap_compile(adapterHandle, &fcode, packet_filter, 1, netmask) > 0)
{
cout<<endl<<"Unable to compile the packet filter. Check Syntax!"<<endl;
pcap_freealldevs(allAdapters);
return -1;
}
// setting the filter
if (pcap_setfilter(adapterHandle, &fcode) > 0)
{
cout<<endl<<"Error setting filter!"<<endl;
pcap_freealldevs(allAdapters);
return -1;
}
// Free the adapter list
pcap_freealldevs( allAdapters );
return -1;
}
printf( "\nCapture session started on adapter %s...\n", adapter->name );
// free the adapter list
pcap_freealldevs( allAdapters );
//--------------------------------------------------------------------------
// this is the most important part of the application
// here we start receiving packet traffic
// then save information inside the packet into array
int retValue;
while( ( retValue = pcap_next_ex( adapterHandle,
&packetHeader,
&packetData ) ) >= 0 )
{
// timeout elapsed if we reach this point
if( retValue == 0 )
continue;
// Just for testing we print only the length of the packet here
//printf( "length of packet: %d\n", packetHeader );
// saving data to array
}
// if we get here, there was an error reading the packets
if( retValue == -1 )
{
printf( "Error reading the packets: %s\n", pcap_geterr( adapterHandle ) );
return -1;
}
system( "PAUSE" );
return 0;
}
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