1 /*

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

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

     4  */

     5 

     6 #include <PacketParser.h>

     7 #include <iomanip>

     8 

     9 PacketParser::PacketParser (int tm)

    10 :PacketReader (tm)

    11 {

    12     protocol = IPPROTO_IP;

    13     port = 0;

    14 }

    15 

    16 PacketParser::PacketParser (std::string filename)

    17 :  PacketReader (filename)

    18 {

    19     protocol = IPPROTO_IP;

    20     port = 0;

    21 }

    22 

    23 PacketParser::~PacketParser ()

    24 {

    25 }

    26 

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

    28 {

    29     proto = getprotobynumber (i);

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

    31 }

    32 

    33 std::string PacketParser::getPacket ()

    34 {

    35     if (port != 0)

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

    37             return "";

    38 

    39     return str;

    40 }

    41 

    42 void PacketParser::setPort (unsigned short p)

    43 {

    44     port = p;

    45 }

    46 

    47 void PacketParser::setProtocol (int proto)

    48 {

    49     protocol = proto;

    50 }

    51 

    52 std::string PacketParser::read ()

    53 {

    54     std::ostringstream s;

    55     struct iphdr *iph;

    56     struct tcphdr *tcph;

    57     struct udphdr *udph;

    58 

    59     struct in_addr src;

    60     struct in_addr dst;

    61 

    62     int size = 0;

    63 

    64     uint i;

    65 

    66     str = PacketReader::read ();

    67 

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

    69 

    70     switch (iph->protocol) {

    71     case IPPROTO_TCP:

    72         size = sizeof (tcphdr);

    73         break;

    74     case IPPROTO_UDP:

    75         size = sizeof (udphdr);

    76         break;

    77     case IPPROTO_ICMP:

    78         size = sizeof (icmphdr);

    79         break;

    80     case IPPROTO_IP:

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

    82         break;

    83     default:

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

    85     }

    86 

    87     src.s_addr = (iph->saddr);

    88     dst.s_addr = (iph->daddr);

    89 

    90     dhost = inet_ntoa (dst);

    91     shost = inet_ntoa (src);

    92 

    93     s.str () = "";

    94 

    95     if (protocol != iph->protocol) {

    96         switch (protocol) {

    97         case IPPROTO_IP:

    98             /*

    99              * filter the content later

   100              */

   101             break;

   102 

   103         case IPPROTO_RAW:

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

   105                 if (!isgraph (str[i]))

   106                     s << ".";

   107                 else

   108                     s << str[i];

   109             }

   110             return s.str ();

   111             break;

   112         default:

   113             /*

   114              * discard packet

   115              */

   116             return s.str ();

   117         }

   118     }

   119 

   120     switch (iph->protocol) {

   121     case IPPROTO_IP:

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

   123         break;

   124 

   125     case IPPROTO_ICMP:

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

   127 

   128         break;

   129 

   130     case IPPROTO_TCP:

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

   132 

   133         sport = ntohs (tcph->source);

   134         dport = ntohs (tcph->dest);

   135 

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

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

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

   139 

   140         if (tcph->urg)

   141             s << (" urg ");

   142         if (tcph->ack) {

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

   144         }

   145         if (tcph->psh)

   146             s << (" psh ");

   147         if (tcph->rst)

   148             s << (" rst ");

   149         if (tcph->syn) {

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

   151         }

   152         if (tcph->fin)

   153             s << (" fin ");

   154 

   155         break;

   156 

   157     case IPPROTO_UDP:

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

   159 

   160         sport = ntohs (udph->source);

   161         dport = ntohs (udph->dest);

   162 

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

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

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

   166 

   167         break;

   168 

   169     default:

   170         s << getProtocol (iph->protocol);

   171         break;

   172     }

   173 

   174     if (port != 0)

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

   176             s.str ("");

   177 

   178     return (s.str ());

   179 }