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# encoding: BINARY
module EventMachine
module WebSocket
module Framing76
def initialize_framing
@data = ''
end
def process_data
debug [:message, @data]
# This algorithm comes straight from the spec
# http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-76#section-5.3
error = false
while !error
return if @data.size == 0
pointer = 0
frame_type = @data.getbyte(pointer)
pointer += 1
if (frame_type & 0x80) == 0x80
# If the high-order bit of the /frame type/ byte is set
length = 0
loop do
return false if !@data.getbyte(pointer)
b = @data.getbyte(pointer)
pointer += 1
b_v = b & 0x7F
length = length * 128 + b_v
break unless (b & 0x80) == 0x80
end
if length > @connection.max_frame_size
raise WSMessageTooBigError, "Frame length too long (#{length} bytes)"
end
if @data.getbyte(pointer+length-1) == nil
debug [:buffer_incomplete, @data]
# Incomplete data - leave @data to accumulate
error = true
else
# Straight from spec - I'm sure this isn't crazy...
# 6. Read /length/ bytes.
# 7. Discard the read bytes.
@data = @data[(pointer+length)..-1]
# If the /frame type/ is 0xFF and the /length/ was 0, then close
if length == 0
@connection.send_data("\xff\x00")
@state = :closing
@connection.close_connection_after_writing
else
error = true
end
end
else
# If the high-order bit of the /frame type/ byte is _not_ set
if @data.getbyte(0) != 0x00
# Close the connection since this buffer can never match
raise WSProtocolError, "Invalid frame received"
end
# Addition to the spec to protect against malicious requests
if @data.size > @connection.max_frame_size
raise WSMessageTooBigError, "Frame length too long (#{@data.size} bytes)"
end
msg = @data.slice!(/\A\x00[^\xff]*\xff/)
if msg
msg.gsub!(/\A\x00|\xff\z/, '')
if @state == :closing
debug [:ignored_message, msg]
else
msg.force_encoding('UTF-8') if msg.respond_to?(:force_encoding)
@connection.trigger_on_message(msg)
end
else
error = true
end
end
end
false
end
# frames need to start with 0x00-0x7f byte and end with
# an 0xFF byte. Per spec, we can also set the first
# byte to a value betweent 0x80 and 0xFF, followed by
# a leading length indicator
def send_text_frame(data)
debug [:sending_text_frame, data]
ary = ["\x00", data, "\xff"]
ary.collect{ |s| s.force_encoding('UTF-8') if s.respond_to?(:force_encoding) }
@connection.send_data(ary.join)
end
end
end
end
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