Сниффер

#define MAX_PACKET_SIZE 0x10000

static char buffer[MAX_PACKET_SIZE];

int main()
{
    WSADATA wsadata;
    SOCKET s;
    char name[128];
    HOSTENT* hostent;
    sockaddr_in addr;
    unsigned long flag = 1;
    int code, iplen, tcplen, datalen;
    IPHeader* ip;
    TCPHeader* tcp;
    ofstream logf;

    logf.open("log.txt");
    WSAStartup(MAKEWORD(2, 0), &wsadata);
    s = socket(AF_INET, SOCK_RAW, IPPROTO_IP);
    gethostname(name, sizeof(name));
    hostent = gethostbyname(name);
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = ((struct in_addr *)hostent->h_addr_list[0])->s_addr;
    bind(s, (sockaddr *)&addr, sizeof(addr));
    ioctlsocket(s, SIO_RCVALL, &flag);
    while (1) {
        code = recv(s, buffer, sizeof(buffer), 0);
        if (code == SOCKET_ERROR) break;
        if (code > 0) {
            ip = (IPHeader *)buffer;
            iplen = 4 * (ip->verlen & 0x0f);
            tcp = (TCPHeader * &buffer[iplen];
            tcplen = (4 * tcp->hdrle);
            logf << "\n\nData\n";
            logf.write(&buffer[iplen+tcplen], code-iplen-tcplen);
            logf.flush();
        }
    }
    logf.close();
    closesocket(s);
    WSACleanup();
    return 0;
}

Data:
 n
”Bу¦ђ`Pд Y#  +OK Hello there.

Data:
 n
”B¦ђrPд <k  +OK Password required.

Data:
 n
”B¦ђ~Pд ф  +OK logged in.

Data:
 n
”B-¦ђ„Pд ВС  +OK 2 13480510

Data:
 n
”B=¦ђЉPд Ќх  +OK POP3 clients that break here, they violate STD53.