#!/usr/bin/env ruby
#
# $Id: tcp2udp 9 2008-03-02 04:44:32Z warchild $
#
#
# Spew TCP packets back at the source but in UDP form.  Gross.
# Pointless.
require 'rubygems'
require 'pcaprub'
require 'racket'
if (ARGV.size < 1)
  puts "Usage: $0 <iface> [filter]"
  exit
end
begin
  p = Pcap::open_live(ARGV[0], 1500, true, 1000)
  unless (ARGV[1].nil?)
    p.setfilter(ARGV[1])
  end
rescue Exception => e
  puts "Pcap: Cannot open device #{ARGV[0]}: #{e}"
  exit
end
p.each do |pkt|
  if (p.datalink == Pcap::DLT_EN10MB) 
    eth = Ethernet.new(pkt)
    case eth.ethertype
      when 0x0800:
        orig_ipv4 = IPv4.new(eth.payload)
        if (orig_ipv4.protocol