#!/usr/bin/env python
# encoding: utf-8
"""
Capture.py

Created by Cody Brocious on 2007-04-07.
Copyright (c) 2006 Cody Brocious All rights reserved.
"""

import sys, struct, pcapy, impacket, impacket.ImpactDecoder

PORT = 2900

class Packet:
    def __init__(self, src, dest, packet):
        self.src = src
        self.dest = dest
        self.packet = packet
        
        self.decode(packet)
    
    def decode(self, packet):
        header, data = packet[0:16], packet[16:]
        
        plen = struct.unpack('<L', header[4:8])[0]
        
        if len(packet) == plen + 0x16:
            print 'OMG!'
        
        return
        
        if self.src[1] == 9008:
            print 'S->C',
        else:
            print 'C->S',
        
        print '%08X - ' % len(data) + ''.join(['%02X ' % ord(c) for c in header[:8]]) + ' ' + ''.join(['%02X ' % ord(c) for c in header[8:]])
    
    def __str__(self):
        ret = '%r -> %r\n' % (self.src, self.dest)
        
        for i in range(0, len(self.packet), 16):
            ret += '%08X  ' % i
            
            for j in range(16):
                if j == 8:
                    ret += ' '
                
                if i+j >= len(self.packet):
                    ret += '   '
                else:
                    ret += '%02X ' % ord(self.packet[i+j])
            
            ret += ' |  '
            
            for j in range(16):
                if j == 8:
                    ret += ' '
                
                if i+j >= len(self.packet):
                    ret += ' '
                else:
                    c = self.packet[i+j]
                    
                    if c.lower() in 'abcdefghijklmnopqrstuvwxyz0123456789`~!@#$%^&*()_+=-[]{}\\|<>?,./':
                        ret += c
                    else:
                        ret += '.'
            
            ret += '\n'
        
        ret += '%08X\n' % len(self.packet)
        
        return ret

class Capture:
    def __init__(self, args):
        # self.reader = pcapy.open_offline(args[0])
        self.reader = pcapy.open_live(args[0], 65536, True, 100)
        self.decoder = impacket.ImpactDecoder.EthDecoder()
        
        while True:
            try:
                header, data = self.reader.next()
            except:
                continue
            eth = self.decoder.decode(data)
            ip = eth.child()
            if ip.__class__ != impacket.ImpactPacket.IP:
                continue
            
            sip = ip.get_ip_src()
            dip = ip.get_ip_dst()
            
            child = ip.child()
            
            if child.__class__ == impacket.ImpactPacket.UDP:
                self.handleUDP(sip, dip, child)
    
    def handleUDP(self, sip, dip, child):
        sport = child.get_uh_sport()
        dport = child.get_uh_dport()
        packet = child.get_data_as_string()
        
        if sport != PORT and dport != PORT:
            return
        
        packet = Packet((sip, sport), (dip, dport), packet)
        print packet
    
if __name__=='__main__':
    Capture(sys.argv[1:])