Class: RfcWebSocket::WebSocket

Inherits:
Object
  • Object
show all
Defined in:
lib/rfc-ws-client.rb

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

Instance Method Summary collapse

Constructor Details

#initialize(uri, protocol = "") ⇒ WebSocket

Returns a new instance of WebSocket.



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# File 'lib/rfc-ws-client.rb', line 29

def initialize(uri, protocol = "")
  uri = URI.parse(uri) unless uri.is_a?(URI)
  @protocol = protocol

  if uri.scheme == "ws"
    default_port = 80
  elsif uri.scheme = "wss"
    default_port = 443
  else
    raise WebSocketError.new("unsupported scheme: #{uri.scheme}")
  end
  host = uri.host + ((!uri.port || uri.port == default_port) ? "" : ":#{uri.port}")
  path = (uri.path.empty? ? "/" : uri.path) + (uri.query ? "?" + uri.query : "")

  @socket = TCPSocket.new(uri.host, uri.port || default_port)
  if uri.scheme == "wss"
    @socket = OpenSSL::SSL::SSLSocket.new(@socket)
    @socket.sync_close = true
    @socket.connect
  end

  request_key = SecureRandom::base64(16)
  write(handshake(host, path, request_key))
  flush()

  status_line = @socket.gets.chomp
  raise WebSocketError.new("bad response: #{status_line}") unless status_line.start_with?("HTTP/1.1 101")

  header = {}
  while line = @socket.gets
    line.chomp!
    break if line.empty?
    if !(line =~ /\A(\S+): (.*)\z/n)
      raise WebSocketError.new("invalid response: #{line}")
    end
    header[$1.downcase] = $2
  end
  raise WebSocketError.new("upgrade missing") unless header["upgrade"]
  raise WebSocketError.new("connection missing") unless header["connection"]
  accept = header["sec-websocket-accept"]
  raise WebSocketError.new("sec-websocket-accept missing") unless accept
  expected_accept = Digest::SHA1.base64digest(request_key + WEB_SOCKET_GUID)
  raise WebSocketError.new("sec-websocket-accept is invalid, actual: #{accept}, expected: #{expected_accept}") unless accept == expected_accept
rescue WebSocketError
  raise
rescue => e
  raise WebSocketError(e.to_s)
end

Instance Method Details

#close(code = 1000, msg = nil) ⇒ Object 



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# File 'lib/rfc-ws-client.rb', line 176

def close(code = 1000, msg = nil)
  write(encode [code ? code : 1000, msg].pack("nA*"), OPCODE_CLOSE)
  @socket.close
rescue WebSocketError
  raise
rescue => e
  raise WebSocketError(e.to_s)
end

#receive ⇒ Object 



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# File 'lib/rfc-ws-client.rb', line 86

def receive
  buffer = ""
  fragmented = nil
  # Loop until something returns
  while true
    b1, b2 = read(2).unpack("CC")
    # first byte
    fin = (b1 & 0x80) != 0
    raise WebSocketError.new("reserved bits must be 0") if (b1 & 0b01110000) != 0
    opcode = b1 & 0x0f
    # second byte
    mask = (b2 & 0x80) != 0
    # we're a client
    raise WebSocketError.new("server->client must not be masked!") if mask
    length = b2 & 0x7f
    if opcode > 7
      raise WebSocketError.new("control frame cannot be fragmented") unless fin
      raise WebSocketError.new("control frame is too large: #{length}") if length > 125
      raise WebSocketError.new("unexpected reserved opcode: #{opcode}") if opcode > 0xA
      raise WebSocketError.new("close frame with payload length 1") if length == 1 and opcode == OPCODE_CLOSE
    elsif opcode != OPCODE_CONTINUATION && opcode != OPCODE_TEXT && opcode != OPCODE_BINARY
      raise WebSocketError.new("unexpected reserved opcode: #{opcode}")
    end
    # extended payload length
    if length == 126
      length = read(2).unpack("n")[0]
    elsif length == 127
      high, low = *read(8).unpack("NN")
      length = high * (2 ** 32) + low
    end
    # payload
    payload = read(length)
    case opcode
    when OPCODE_CONTINUATION
      raise WebSocketError.new("no frame to continue") unless fragmented
      if fragmented == :binary
        buffer << payload
      else
        buffer << payload.force_encoding("UTF-8")
      end
      if fin
        raise WebSocketError.new("invalid utf8", 1007) if fragmented == :text and !valid_utf8?(buffer)
        return buffer, fragmented == :binary
      else
        next
      end
    when OPCODE_TEXT
      raise WebSocketError.new("unexpected opcode in continuation mode") if fragmented
      if !fin
        fragmented = :text
        buffer << payload.force_encoding("UTF-8")
        next
      else
        raise WebSocketError.new("invalid utf8", 1007) unless valid_utf8?(payload)
        return payload, false
      end
    when OPCODE_BINARY
      raise WebSocketError.new("unexpected opcode in continuation mode") if fragmented
      if !fin
        fragmented = :binary
        buffer << payload
      else
        return payload, true
      end
    when OPCODE_CLOSE
      code, explain = payload.unpack("nA*")
      if explain && !valid_utf8?(explain)
        close(1007)
      else
        close(response_close_code(code))
      end
      return nil, nil
    when OPCODE_PING
      write(encode(payload, OPCODE_PONG))
      next
    when OPCODE_PONG
      next
    else
      raise WebSocketError.new("received unknown opcode: #{opcode}")
    end
  end
rescue EOFError
  return nil, nil
rescue WebSocketError => e
  close(e.code)
  raise e
rescue => e
  raise WebSocketError(e.to_s)
end

#send_message(message, opts = {binary: false}) ⇒ Object 



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# File 'lib/rfc-ws-client.rb', line 78

def send_message(message, opts = {binary: false})
  write(encode(message, opts[:binary] ? OPCODE_BINARY : OPCODE_TEXT))
rescue WebSocketError
  raise
rescue => e
  raise WebSocketError(e.to_s)
end