#!/usr/bin/python
#
# Copyright (c) 2007 OLPC
# Author: Ricardo Carrano <carrano at laptop.org>
# Version 0.1.2
#
# this program is free software; you can redistribute it and/or modify
# it under the terms of the gnu general public license as published by
# the free software foundation; either version 2 of the license, or
# (at your option) any later version.
#
# this program is distributed in the hope that it will be useful,
# but without any warranty; without even the implied warranty of
# merchantability or fitness for a particular purpose.  see the
# gnu general public license for more details.
#
# you should have received a copy of the gnu general public license
# along with this program; if not, write to the free software
# foundation, inc., 51 franklin st, fifth floor, boston, ma  02110-1301  usa


import sys
import commands
import math
from optparse import OptionParser

arguments = OptionParser()
arguments.add_option("-f","--pcap-file",
                     dest="pcapfile",
                     help="Capture dump")
arguments.add_option("-t","--text-file",
                     dest="textfile",
                     help="Capture already converted/filtered")
arguments.add_option("-i","--interval",
                     dest="interval",
                     help="Consolidation interval in seconds")
arguments.add_option("-w","--filter",
                     dest="filter",
                     help="Wireshark filter")
arguments.add_option("-o","--output-format",
                     dest="output",
                     help="Output Format [csv, lines] ")
arguments.add_option("--no-fcs",
                     action="store_false",
                     dest="crc",
                     default=True,
                     help="don't check if frames have bad crc")
(options, args) = arguments.parse_args()

if not (options.pcapfile or options.textfile) :
   print "input file is mandatory"
   sys.exit(0)
filter_exp = ''
filter = ''
if options.crc == True:
   filter += 'wlan.fcs_good == 1'
   if options.filter:
      filter += ' and '+options.filter
else:
   filter += options.filter
if options.crc or options.filter:
   filter_exp = '-R "'+filter+'"'
if options.pcapfile:
   pcapfile = options.pcapfile
   inputfile = pcapfile
if options.textfile:
   textfile = options.textfile
   inputfile = textfile
else:
   textfile = pcapfile+'.tmp3'
   filter_cmd='tshark -r %s %s -T fields -e frame.time_relative -e radiotap.datarate -e frame.len > %s' % (pcapfile, filter_exp, textfile)
   s, o = commands.getstatusoutput(filter_cmd)
if options.interval:
   interval = float(options.interval)
else:
   interval = 1
timeslot = 0
lastslot = 0
airtime = [0]


fd = open(textfile, 'r')

cck_datarates = ('2', '4', '11', '22')
ofdm_datarates = ('12', '18', '24', '36', '48', '72', '96', '108')

for line in fd:
   time, rate, size = line.split('\t')
   size = size.strip('\n')
   if rate in cck_datarates:
      airsize = 192 + float(size) * 16 / float (rate)
   elif rate in ofdm_datarates:
      airsize = 26 + float(size) * 16 / float (rate)
   else:
      airsize = 0
   timeslot = int(math.floor(float(time) / interval))
   if timeslot > lastslot:
      for slot in range(lastslot, timeslot): 
         airtime.append(0)
   airtime[timeslot] += airsize / (interval * 1000000)
   lastslot = timeslot

if options.output == "csv":
   for i in airtime:
      print str(i)+',',
else:
   for i in range(0, len(airtime)):
      print "[%s - %s): %.2f%%" % (i*interval, (i+1)*interval, airtime[i] * 100)