Module: EventMachine::WebSocket::Framing05
Constant Summary collapse
- MAXIMUM_FRAME_LENGTH =
Set the max frame lenth to very high value (10MB) until there is a limit specified in the spec to protect against malicious attacks
10 * 1024 * 1024
Instance Method Summary collapse
- #initialize_framing ⇒ Object
- #process_data(newdata) ⇒ Object
- #send_frame(frame_type, application_data) ⇒ Object
- #send_text_frame(data) ⇒ Object
Instance Method Details
#initialize_framing ⇒ Object
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# File 'lib/em-websocket/framing05.rb', line 11 def initialize_framing @data = MaskedString.new @application_data_buffer = '' # Used for MORE frames end |
#process_data(newdata) ⇒ Object
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# File 'lib/em-websocket/framing05.rb', line 16 def process_data(newdata) error = false while !error && @data.size > 5 # mask plus first byte present pointer = 0 @data.read_mask pointer += 4 fin = (@data.getbyte(pointer) & 0b10000000) == 0b10000000 # Ignoring rsv1-3 for now opcode = @data.getbyte(pointer) & 0b00001111 pointer += 1 # Ignoring rsv4 length = @data.getbyte(pointer) & 0b01111111 pointer += 1 payload_length = case length when 127 # Length defined by 8 bytes # Check buffer size if @data.getbyte(pointer+8-1) == nil debug [:buffer_incomplete, @data] error = true next end # Only using the last 4 bytes for now, till I work out how to # unpack 8 bytes. I'm sure 4GB frames will do for now :) l = @data.getbytes(pointer+4, 4).unpack('N').first pointer += 8 l when 126 # Length defined by 2 bytes # Check buffer size if @data.getbyte(pointer+2-1) == nil debug [:buffer_incomplete, @data] error = true next end l = @data.getbytes(pointer, 2).unpack('n').first pointer += 2 l else length end # Addition to the spec to protect against malicious requests if payload_length > MAXIMUM_FRAME_LENGTH raise DataError, "Frame length too long (#{payload_length} bytes)" end # Check buffer size if @data.getbyte(pointer+payload_length-1) == nil debug [:buffer_incomplete, @data] error = true next end # Read application data application_data = @data.getbytes(pointer, payload_length) pointer += payload_length # Throw away data up to pointer @data.unset_mask @data.slice!(0...pointer) frame_type = opcode_to_type(opcode) if frame_type == :continuation && !@frame_type raise WebSocketError, 'Continuation frame not expected' end if !fin debug [:moreframe, frame_type, application_data] @application_data_buffer << application_data @frame_type = frame_type else # Message is complete if frame_type == :continuation @application_data_buffer << application_data (@frame_type, '', @application_data_buffer) @application_data_buffer = '' @frame_type = nil else (frame_type, '', application_data) end end end # end while end |
#send_frame(frame_type, application_data) ⇒ Object
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# File 'lib/em-websocket/framing05.rb', line 107 def send_frame(frame_type, application_data) debug [:sending_frame, frame_type, application_data] if @state == :closing && data_frame?(frame_type) raise WebSocketError, "Cannot send data frame since connection is closing" end frame = '' opcode = type_to_opcode(frame_type) byte1 = opcode | 0b10000000 # fin bit set, rsv1-3 are 0 frame << byte1 length = application_data.size if length <= 125 byte2 = length # since rsv4 is 0 frame << byte2 elsif length < 65536 # write 2 byte length frame << 126 frame << [length].pack('n') else # write 8 byte length frame << 127 frame << [length >> 32, length & 0xFFFFFFFF].pack("NN") end frame << application_data @connection.send_data(frame) end |
#send_text_frame(data) ⇒ Object
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# File 'lib/em-websocket/framing05.rb', line 137 def send_text_frame(data) send_frame(:text, data) end |