path: root/third_party/websockify/other/websocket.rb

# Python WebSocket library with support for "wss://" encryption.
# Copyright 2011 Joel Martin
# Licensed under LGPL version 3 (see docs/LICENSE.LGPL-3)
# 
# Supports following protocol versions:
#     - http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-75
#     - http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-76
#     - http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-10

require 'gserver'
require 'stringio'
require 'digest/md5'
require 'digest/sha1'
require 'base64'

class EClose < Exception
end

class WebSocketServer < GServer
  @@Buffer_size = 65536

  #
  # WebSocket constants
  #
  @@Server_handshake_hixie = "HTTP/1.1 101 Web Socket Protocol Handshake\r
Upgrade: WebSocket\r
Connection: Upgrade\r
%sWebSocket-Origin: %s\r
%sWebSocket-Location: %s://%s%s\r
"

  @@Server_handshake_hybi = "HTTP/1.1 101 Switching Protocols\r
Upgrade: websocket\r
Connection: Upgrade\r
Sec-WebSocket-Accept: %s\r
"
  @@GUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"


  def initialize(opts)
    vmsg "in WebSocketServer.initialize"
    port = opts['listen_port']
    host = opts['listen_host'] || GServer::DEFAULT_HOST

    super(port, host)
   
    @@client_id = 0  # Track client number total on class

    @verbose = opts['verbose']
    @opts = opts
  end
  
  def serve(io)
    @@client_id += 1

    # Initialize per thread state
    t = Thread.current
    t[:my_client_id] = @@client_id
    t[:send_parts] = []
    t[:recv_part] = nil
    t[:base64] = nil

    puts "in serve, client: #{t[:client].inspect}"

    begin
      t[:client] = do_handshake(io)
      new_client(t[:client])
    rescue EClose => e
      msg "Client closed: #{e.message}"
      return
    rescue Exception => e
      msg "Uncaught exception: #{e.message}"
      msg "Trace: #{e.backtrace}"
      return
    end

    msg "Client disconnected"
  end

  #
  # WebSocketServer logging/output functions
  #
  def traffic(token)
    if @verbose then print token; STDOUT.flush; end
  end

  def msg(msg)
    puts "% 3d: %s" % [Thread.current[:my_client_id], msg]
  end

  def vmsg(msg)
    if @verbose then msg(msg) end
  end

  #
  # WebSocketServer general support routines
  #
  def gen_md5(h)
    key1 = h['sec-websocket-key1']
    key2 = h['sec-websocket-key2']
    key3 = h['key3']
    spaces1 = key1.count(" ")
    spaces2 = key2.count(" ")
    num1 = key1.scan(/[0-9]/).join('').to_i / spaces1
    num2 = key2.scan(/[0-9]/).join('').to_i / spaces2

    return Digest::MD5.digest([num1, num2, key3].pack('NNa8'))
  end

  def unmask(buf, hlen, length)
    pstart = hlen + 4
    mask = buf[hlen...hlen+4]
    data = buf[pstart...pstart+length]
    #data = data.bytes.zip(mask.bytes.cycle(length)).map { |d,m| d^m }
    for i in (0...data.length) do
      data[i] ^= mask[i%4]
    end
    return data
  end

  def encode_hybi(buf, opcode, base64=false)
    if base64
      buf = Base64.encode64(buf).gsub(/\n/, '')
    end

    b1 = 0x80 | (opcode & 0x0f) # FIN + opcode
    payload_len = buf.length
    if payload_len <= 125
      header = [b1, payload_len].pack('CC')
    elsif payload_len > 125 && payload_len < 65536
      header = [b1, 126, payload_len].pack('CCn')
    elsif payload_len >= 65536
      header = [b1, 127, payload_len >> 32,
                         payload_len & 0xffffffff].pack('CCNN')
    end

    return [header + buf, header.length, 0]
  end

  def decode_hybi(buf, base64=false)
    f = {'fin'          => 0,
         'opcode'       => 0,
         'hlen'         => 2,
         'length'       => 0,
         'payload'      => nil,
         'left'         => 0,
         'close_code'   => nil,
         'close_reason' => nil}

    blen = buf.length
    f['left'] = blen

    if blen < f['hlen'] then return f end # incomplete frame

    b1, b2 = buf.unpack('CC')
    f['opcode'] = b1 & 0x0f
    f['fin']    = (b1 & 0x80) >> 7
    has_mask    = (b2 & 0x80) >> 7

    f['length'] = b2 & 0x7f

    if f['length'] == 126
      f['hlen'] = 4
      if blen < f['hlen'] then return f end # incomplete frame
      f['length'] = buf.unpack('xxn')[0]
    elsif f['length'] == 127
      f['hlen'] = 10
      if blen < f['hlen'] then return f end # incomplete frame
      top, bottom = buf.unpack('xxNN')
      f['length'] = (top << 32) & bottom
    end

    full_len = f['hlen'] + has_mask * 4 + f['length']

    if blen < full_len then return f end # incomplete frame

    # number of bytes that are part of the next frame(s)
    f['left'] = blen - full_len

    if has_mask > 0
      f['payload'] = unmask(buf, f['hlen'], f['length'])
    else
      f['payload'] = buf[f['hlen']...full_len]
    end

    if base64 and [1, 2].include?(f['opcode'])
      f['payload'] = Base64.decode64(f['payload'])
    end

    # close frame
    if f['opcode'] == 0x08
      if f['length'] >= 2
        f['close_code'] = f['payload'].unpack('n')
      end
      if f['length'] > 3
        f['close_reason'] = f['payload'][2...f['payload'].length]
      end
    end

    return f
  end

  def encode_hixie(buf)
    return ["\x00" + Base64.encode64(buf).gsub(/\n/, '') + "\xff", 1, 1]
  end

  def decode_hixie(buf)
    last = buf.index("\377")
    return {'payload' => Base64.decode64(buf[1...last]),
            'hlen' => 1,
            'length' => last - 1,
            'left' => buf.length - (last + 1)}
  end

  def send_frames(bufs)
    t = Thread.current
    if bufs.length > 0
      encbuf = ""
      bufs.each do |buf|
        if t[:version].start_with?("hybi")
          if t[:base64]
            encbuf, lenhead, lentail = encode_hybi(
              buf, opcode=1