/*

 *  $Id: PacketParser.cpp 54 2008-01-10 00:24:52Z mbroeker $

 * $URL: http://localhost/svn/cpp/qMonitor/trunk/PacketParser.cpp $

 */

#include <PacketParser.h>

#include <iomanip>

PacketParser::PacketParser (int tm)

:PacketReader (tm)

{

    protocol = IPPROTO_IP;

    port = 0;

}

PacketParser::PacketParser (std::string filename)

:  PacketReader (filename)

{

    protocol = IPPROTO_IP;

    port = 0;

}

PacketParser::~PacketParser ()

{

}

std::string PacketParser::getProtocol (int i)

{

    proto = getprotobynumber (i);

    return ((proto != NULL) ? proto->p_name : "unknown");

}

std::string PacketParser::getPacket ()

{

    if (port != 0)

        if ((sport != port) && (dport != port))

            return "";

    return str;

}

void PacketParser::setPort (unsigned short p)

{

    port = p;

}

void PacketParser::setProtocol (int proto)

{

    protocol = proto;

}

std::string PacketParser::read ()

{

    std::ostringstream s;

    struct iphdr *iph;

    struct tcphdr *tcph;

    struct udphdr *udph;

    struct in_addr src;

    struct in_addr dst;

    int size = 0;

    uint i;

    str = PacketReader::read ();

    iph = (struct iphdr *)(str.c_str () + sizeof (struct ethhdr));

    switch (iph->protocol) {

    case IPPROTO_TCP:

        size = sizeof (tcphdr);

        break;

    case IPPROTO_UDP:

        size = sizeof (udphdr);

        break;

    case IPPROTO_ICMP:

        size = sizeof (icmphdr);

        break;

    case IPPROTO_IP:

        size += (sizeof (ethhdr) + sizeof (iphdr));

        break;

    default:

        size += (sizeof (ethhdr) + sizeof (iphdr));

    }

    src.s_addr = (iph->saddr);

    dst.s_addr = (iph->daddr);

    dhost = inet_ntoa (dst);

    shost = inet_ntoa (src);

    s.str () = "";

    if (protocol != iph->protocol) {

        switch (protocol) {

        case IPPROTO_IP:

            /*

             * filter the content later

             */

            break;

        case IPPROTO_RAW:

            for (i = size; i < str.length (); i++) {

                if (!isgraph (str[i]))

                    s << ".";

                else

                    s << str[i];

            }

            return s.str ();

            break;

        default:

            /*

             * discard packet

             */

            return s.str ();

        }

    }

    switch (iph->protocol) {

    case IPPROTO_IP:

        s << getProtocol (iph->protocol) << " " << std::setw (15) << shost << " ==> " << std::setw (15) << dhost;

        break;

    case IPPROTO_ICMP:

        s << getProtocol (iph->protocol) << " " << std::setw (15) << shost << " ==> " << std::setw (15) << dhost;

        break;

    case IPPROTO_TCP:

        tcph = (struct tcphdr *)(str.c_str () + sizeof (struct ethhdr) + sizeof (struct iphdr));

        sport = ntohs (tcph->source);

        dport = ntohs (tcph->dest);

        s << getProtocol (iph->protocol) << " "

            << std::setw (15) << shost << ":" << std::setw (5) << sport

            << " ==> " << std::setw (15) << dhost << ":" << std::setw (5) << dport;

        if (tcph->urg)

            s << (" urg ");

        if (tcph->ack) {

            s << (" ack ") << ntohl (tcph->ack_seq);

        }

        if (tcph->psh)

            s << (" psh ");

        if (tcph->rst)

            s << (" rst ");

        if (tcph->syn) {

            s << (" syn ") << ntohl (tcph->seq);

        }

        if (tcph->fin)

            s << (" fin ");

        break;

    case IPPROTO_UDP:

        udph = (struct udphdr *)(str.c_str () + sizeof (struct ethhdr) + sizeof (struct iphdr));

        sport = ntohs (udph->source);

        dport = ntohs (udph->dest);

        s << getProtocol (iph->protocol) << " "

            << std::setw (15) << shost << ":" << std::setw (5) << sport

            << " ==> " << std::setw (15) << dhost << ":" << std::setw (5) << dport;

        break;

    default:

        s << getProtocol (iph->protocol);

        break;

    }

    if (port != 0)

        if ((sport != port) && (dport != port))

            s.str ("");

    return (s.str ());

}