proxy.rb

# Based on https://gist.github.com/74107 by # Copyright (C) 2009 Torsten Becker <[email protected]>
#
# Rewrited by gazay

require 'socket'
require 'uri'

class Proxy

  attr_accessor :socket

  def run(port)
    begin
      socket = TCPServer.new port
      puts "listening on localhost:#{port}"

      loop do
        s = socket.accept
        Thread.new s, &method(:handle_request)
      end
    ensure
      if @socket
        @socket.close
        puts 'Socked closed..'
      end
      puts 'Quitting.'
    end
  end

  def handle_request(client)
    destination = client.readline
    verb, url, version, uri = parse_request destination
    server = TCPSocket.new(uri.host, (uri.port.nil? ? 80 : uri.port))

    puts "#{verb} - #{url}"

    send_request server, client, destination
    send_response client, server

    client.close
    server.close
  end

  def parse_request(destination)
    verb    = destination[/^\w+/]
    url     = destination[/^\w+\s+(\S+)/, 1]
    version = destination[/HTTP\/(1\.\d)\s*$/, 1]
    uri     = URI::parse url
    [verb, url, version, uri]
  end

  def send_request(server, request, destination)
    server.write destination

    content_size = 0

    request.lines.each do |line|
      if line =~ /^Content-Length:\s+(\d+)\s*$/
        content_size = $1.to_i
      end

      # Strip proxy headers
      if line =~ /^proxy/i
        next
      elsif line.strip.empty?
        server.write("Connection: close\r\n\r\n")

        if content_size >= 0
          server.write(request.read(content_size))
        end

        break
      else
        server.write(line)
      end
    end
  end

  def send_response(client, response)
    buff = ""
    loop do
      response.read(4048, buff)
      client.write(buff)
      break if buff.size < 4048
    end
  end

end

# Get parameters and start the server
if ARGV.empty?
  port = 8080
elsif ARGV.size == 1
  port = ARGV[0].to_i
elsif ARGV.size == 2 and ARGV[0] == '-p'
  port = ARGV[1].to_i
else
  puts 'Usage: proxy.rb [port] or proxy.rb -p [port]'
  exit 1
end

Proxy.new.run port