http.rb

#!/usr/bin/env ruby

begin
  require 'pcaplet'
rescue LoadError
  require 'rubygems'
  require 'pcaplet'
end

p = Pcaplet.new(ARGV.join(' '))

HTTP_REQUEST  = Pcap::Filter.new('tcp and dst port 80', p.capture)
HTTP_RESPONSE = Pcap::Filter.new('tcp and src port 80', p.capture)

p.each_packet do |pkt|
  if pkt.tcp? then
    data = pkt.tcp_data
    case pkt
    when HTTP_REQUEST
      if data and data =~ /^GET\s+(\S+)/
        path = $1
        host = pkt.dst.to_s
        if data =~ /^Host:\s+(\S+)/
          host = $1
        end
        host << ":#{pkt.dst_port}" if pkt.dport != 80
        puts "#{pkt.src}:#{pkt.sport} > GET http://#{host}#{path}"
      end
    when HTTP_RESPONSE
      if data and data =~ /^(HTTP\/.*)$/
        status = $1
        puts "#{pkt.dst}:#{pkt.dport} < #{status}"
      end
    end
  end
end