在Windows 7上捕获数据包

recvfrom

#include <Winsock2.h>
#include <Mstcpip.h>
#include <iostream>
#include <string>
using namespace std;
#pragma comment(lib,\"Ws2_32.lib\")

struct SIP4HEADER
{
    u_char  ver_ihl;    // Version (4 bits) + Internet header length (4 bits)
    u_char  tos;        // Type of service 
    u_short tlen;       // Total length 
    u_short ident;      // Identification
    u_short flags_fo;   // Flags (3 bits) + Fragment offset (13 bits)
    u_char  ttl;        // Time to live
    u_char  proto;      // Protocol
    u_short crc;        // Header checksum
    u_long  saddr;      // Source address
    u_long  daddr;      // Destination address
    u_int   op_pad;     // Option + Padding
};    

// Error handling parts is removed for clarity    
void main()
{
    WSAData wsa={0};
    WSAStartup(MAKEWORD(2,2),&wsa);

    string strIPAddress;
    cout << \"Enter a local IP address to monitor: \";
    cin >> strIPAddress;
    SOCKET ListenSocket = socket(AF_INET, SOCK_RAW, IPPROTO_IP);
    sockaddr_in sa_in;
    sa_in.sin_family = AF_INET;
    sa_in.sin_addr.s_addr = inet_addr( strIPAddress.c_str() ); //My local IP address
    sa_in.sin_port = htons(0);      


    bind(ListenSocket,(SOCKADDR *) &sa_in, sizeof(sa_in));

    int rcv=RCVALL_IPLEVEL;
    DWORD b=0;
    WSAIoctl(ListenSocket,SIO_RCVALL,&rcv,sizeof(rcv),0,0,&b,0,0);

    char buf[2000];
    SIP4HEADER* ih = (SIP4HEADER*)buf;
    DWORD ReceivedKBytes = 0;
    DWORD t = 0;
    while( recvfrom(ListenSocket,buf,_countof(buf),0,NULL,NULL)!=-1 )
    {
        if(sa_in.sin_addr.s_addr == ih->daddr)
            t += ntohs(ih->tlen) ; 
        // update each 20KB
        if(t > 20*1024) 
        {
            t=0;
            ReceivedKBytes += 20;
            cout << \"Received KBs: \" << ReceivedKBytes << endl;
        }
    }
}

IPPROTO_IP

bind

bind

recvfrom

IPPROTO_IP

IPPROTO_TCP