Class: WebSocket

Inherits:
Object
  • Object
show all
Defined in:
lib/web_socket.rb

Defined Under Namespace

Classes: Error

Constant Summary collapse

WEB_SOCKET_GUID =
"258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
OPCODE_CONTINUATION =
0x00
OPCODE_TEXT =
0x01
OPCODE_BINARY =
0x02
OPCODE_CLOSE =
0x08
OPCODE_PING =
0x09
OPCODE_PONG =
0x0a

Class Attribute Summary collapse

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(arg, params = {}) ⇒ WebSocket

Returns a new instance of WebSocket.



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# File 'lib/web_socket.rb', line 37

def initialize(arg, params = {})
  if params[:server] # server

    @server = params[:server]
    @socket = arg
    line = gets().chomp()
    if !(line =~ /\AGET (\S+) HTTP\/1.1\z/n)
      raise(WebSocket::Error, "invalid request: #{line}")
    end
    @path = $1
    read_header()
    if @header["sec-websocket-version"]
      @web_socket_version = @header["sec-websocket-version"]
      @key3 = nil
    elsif @header["sec-websocket-key1"] && @header["sec-websocket-key2"]
      @web_socket_version = "hixie-76"
      @key3 = read(8)
    else
      @web_socket_version = "hixie-75"
      @key3 = nil
    end
    if !@server.accepted_origin?(self.origin)
      raise(WebSocket::Error,
        ("Unaccepted origin: %s (server.accepted_domains = %p)\n\n" +
          "To accept this origin, write e.g. \n" +
          "  WebSocketServer.new(..., :accepted_domains => [%p]), or\n" +
          "  WebSocketServer.new(..., :accepted_domains => [\"*\"])\n") %
        [self.origin, @server.accepted_domains, @server.origin_to_domain(self.origin)])
    end
    @handshaked = false

  else # client
    
    @web_socket_version = "hixie-76"
    uri = arg.is_a?(String) ? URI.parse(arg) : arg

    if uri.scheme == "ws"
      default_port = 80
    elsif uri.scheme = "wss"
      default_port = 443
    else
      raise(WebSocket::Error, "unsupported scheme: #{uri.scheme}")
    end

    @path = (uri.path.empty? ? "/" : uri.path) + (uri.query ? "?" + uri.query : "")
    host = uri.host + (uri.port == default_port ? "" : ":#{uri.port}")
    origin = params[:origin] || "http://#{uri.host}"
    key1 = generate_key()
    key2 = generate_key()
    key3 = generate_key3()

    socket = TCPSocket.new(uri.host, uri.port || default_port)

    if uri.scheme == "ws"
      @socket = socket
    else
      @socket = ssl_handshake(socket)
    end

    write(
      "GET #{@path} HTTP/1.1\r\n" +
      "Upgrade: WebSocket\r\n" +
      "Connection: Upgrade\r\n" +
      "Host: #{host}\r\n" +
      "Origin: #{origin}\r\n" +
      "Sec-WebSocket-Key1: #{key1}\r\n" +
      "Sec-WebSocket-Key2: #{key2}\r\n" +
      "\r\n" +
      "#{key3}")
    flush()

    line = gets().chomp()
    raise(WebSocket::Error, "bad response: #{line}") if !(line =~ /\AHTTP\/1.1 101 /n)
    read_header()
    if (@header["sec-websocket-origin"] || "").downcase() != origin.downcase()
      raise(WebSocket::Error,
        "origin doesn't match: '#{@header["sec-websocket-origin"]}' != '#{origin}'")
    end
    reply_digest = read(16)
    expected_digest = hixie_76_security_digest(key1, key2, key3)
    if reply_digest != expected_digest
      raise(WebSocket::Error,
        "security digest doesn't match: %p != %p" % [reply_digest, expected_digest])
    end
    @handshaked = true

  end
  @received = []
  @buffer = ""
  @closing_started = false
end

Class Attribute Details

.debugObject

Returns the value of attribute debug.



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# File 'lib/web_socket.rb', line 21

def debug
  @debug
end

Instance Attribute Details

#headerObject (readonly)

Returns the value of attribute header.



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# File 'lib/web_socket.rb', line 129

def header
  @header
end

#pathObject (readonly)

Returns the value of attribute path.



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# File 'lib/web_socket.rb', line 129

def path
  @path
end

#serverObject (readonly)

Returns the value of attribute server.



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# File 'lib/web_socket.rb', line 129

def server
  @server
end

Instance Method Details

#close(code = 1005, reason = "", origin = :self) ⇒ Object

Does closing handshake.



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# File 'lib/web_socket.rb', line 266

def close(code = 1005, reason = "", origin = :self)
  if !@closing_started
    case @web_socket_version
      when "hixie-75", "hixie-76"
        write("\xff\x00")
      else
        if code == 1005
          payload = ""
        else
          payload = [code].pack("n") + force_encoding(reason.dup(), "ASCII-8BIT")
        end
        send_frame(OPCODE_CLOSE, payload, false)
    end
  end
  @socket.close() if origin == :peer
  @closing_started = true
end

#close_socketObject



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# File 'lib/web_socket.rb', line 284

def close_socket()
  @socket.close()
end

#handshake(status = nil, header = {}) ⇒ Object



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# File 'lib/web_socket.rb', line 131

def handshake(status = nil, header = {})
  if @handshaked
    raise(WebSocket::Error, "handshake has already been done")
  end
  status ||= "101 Switching Protocols"
  def_header = {}
  case @web_socket_version
    when "hixie-75"
      def_header["WebSocket-Origin"] = self.origin
      def_header["WebSocket-Location"] = self.location
      extra_bytes = ""
    when "hixie-76"
      def_header["Sec-WebSocket-Origin"] = self.origin
      def_header["Sec-WebSocket-Location"] = self.location
      extra_bytes = hixie_76_security_digest(
        @header["Sec-WebSocket-Key1"], @header["Sec-WebSocket-Key2"], @key3)
    else
      def_header["Sec-WebSocket-Accept"] = security_digest(@header["sec-websocket-key"])
      extra_bytes = ""
  end
  header = def_header.merge(header)
  header_str = header.map(){ |k, v| "#{k}: #{v}\r\n" }.join("")
  # Note that Upgrade and Connection must appear in this order.
  write(
    "HTTP/1.1 #{status}\r\n" +
    "Upgrade: websocket\r\n" +
    "Connection: Upgrade\r\n" +
    "#{header_str}\r\n#{extra_bytes}")
  flush()
  @handshaked = true
end

#hostObject



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# File 'lib/web_socket.rb', line 243

def host
  return @header["host"]
end

#locationObject



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# File 'lib/web_socket.rb', line 261

def location
  return "ws://#{self.host}#{@path}"
end

#originObject



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# File 'lib/web_socket.rb', line 247

def origin
  case @web_socket_version
    when "7", "8"
      name = "sec-websocket-origin"
    else
      name = "origin"
  end
  if @header[name]
    return @header[name]
  else
    raise(WebSocket::Error, "%s header is missing" % name)
  end
end

#receiveObject



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# File 'lib/web_socket.rb', line 177

def receive()
  if !@handshaked
    raise(WebSocket::Error, "call WebSocket\#handshake first")
  end
  case @web_socket_version
    
    when "hixie-75", "hixie-76"
      packet = gets("\xff")
      return nil if !packet
      if packet =~ /\A\x00(.*)\xff\z/nm
        return force_encoding($1, "UTF-8")
      elsif packet == "\xff" && read(1) == "\x00" # closing
        close(1005, "", :peer)
        return nil
      else
        raise(WebSocket::Error, "input must be either '\\x00...\\xff' or '\\xff\\x00'")
      end
    
    else
      begin
        bytes = read(2).unpack("C*")
        fin = (bytes[0] & 0x80) != 0
        opcode = bytes[0] & 0x0f
        mask = (bytes[1] & 0x80) != 0
        plength = bytes[1] & 0x7f
        if plength == 126
          bytes = read(2)
          plength = bytes.unpack("n")[0]
        elsif plength == 127
          bytes = read(8)
          (high, low) = bytes.unpack("NN")
          plength = high * (2 ** 32) + low
        end
        if @server && !mask
          # Masking is required.
          @socket.close()
          raise(WebSocket::Error, "received unmasked data")
        end
        mask_key = mask ? read(4).unpack("C*") : nil
        payload = read(plength)
        payload = apply_mask(payload, mask_key) if mask
        case opcode
          when OPCODE_TEXT
            return force_encoding(payload, "UTF-8")
          when OPCODE_BINARY
            raise(WebSocket::Error, "received binary data, which is not supported")
          when OPCODE_CLOSE
            close(1005, "", :peer)
            return nil
          when OPCODE_PING
            raise(WebSocket::Error, "received ping, which is not supported")
          when OPCODE_PONG
          else
            raise(WebSocket::Error, "received unknown opcode: %d" % opcode)
        end
      rescue EOFError
        return nil
      end
    
  end
end

#send(data) ⇒ Object



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# File 'lib/web_socket.rb', line 163

def send(data)
  if !@handshaked
    raise(WebSocket::Error, "call WebSocket\#handshake first")
  end
  case @web_socket_version
    when "hixie-75", "hixie-76"
      data = force_encoding(data.dup(), "ASCII-8BIT")
      write("\x00#{data}\xff")
      flush()
    else
      send_frame(OPCODE_TEXT, data, !@server)
  end
end

#tcp_socketObject



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# File 'lib/web_socket.rb', line 239

def tcp_socket
  return @socket
end