108 lines
2.9 KiB
Ruby
108 lines
2.9 KiB
Ruby
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require 'socket' # Provides TCPServer and TCPSocket classes
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require 'digest/sha1'
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class WebSocketServer
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def initialize(host="localhost",port=2345)
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@server=TCPServer.new(host,port)
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end
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def accept()
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# Wait for a connection
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@socket = @server.accept
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# Read the HTTP request. We know it's finished when we see a line with nothing but \r\n
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http_request = ""
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while (line = @socket.gets) && (line != "\r\n")
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http_request += line
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end
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# Grab the security key from the headers. If one isn't present, close the connection.
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if matches = http_request.match(/^Sec-WebSocket-Key: (\S+)/)
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websocket_key = matches[1]
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puts "Websocket handshake detected with key: #{websocket_key}"
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else
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puts "Aborting non-websocket connection"
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socket.close
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return
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end
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response_key = Digest::SHA1.base64digest([websocket_key, "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"].join)
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puts "Responding to handshake with key: #{response_key}"
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@socket.write <<-eos
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HTTP/1.1 101 Switching Protocols
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Upgrade: websocket
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Connection: Upgrade
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Sec-WebSocket-Accept: #{response_key}
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eos
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puts "Handshake completed."
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end
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def recv()
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first_byte = @socket.getbyte
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fin = first_byte & 0b10000000
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opcode = first_byte & 0b00001111
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fin = fin >> 7
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fin = (fin ? true : false)
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puts "Got frame. FIN:#{fin}. Opcode:#{opcode}"
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raise "We don't support continuations" unless fin
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unless opcode == 1 or opcode == 8
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puts "We only support text data and close frame"
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send("",3)
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end
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if opcode == 1
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second_byte = @socket.getbyte
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is_masked = second_byte & 0b10000000
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payload_size = second_byte & 0b01111111
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raise "All incoming frames should be masked according to the websocket spec" unless is_masked
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raise "We only support payloads < 126 bytes in length" unless payload_size < 126
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puts "Payload size: #{payload_size} bytes"
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mask = 4.times.map {@socket.getbyte}
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puts "Got mask: #{mask.inspect}"
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data = payload_size.times.map {@socket.getbyte}
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puts "Got masked data: #{data.inspect}"
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unmasked_data = data.each_with_index.map { |byte, i| byte ^ mask[i % 4] }
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puts "Unmasked the data: #{unmasked_data.inspect}"
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string=unmasked_data.pack('C*').force_encoding('utf-8')
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puts "Converted to a string: #{string}"
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return string
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elsif opcode == 8
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send("",0)
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return false
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end
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end
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def send(message,closetype=false)
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if closetype
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puts "Sending close frame"
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output=[0x88,2,3,0xe8+closetype]
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@socket.write output.pack("C*")
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@socket.close
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else
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puts "Sending #{message}"
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output = [0x81, message.size, message]
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@socket.write output.pack("CCA#{message.size}")
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end
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end
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end
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serv=WebSocketServer.new
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serv.accept
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while true
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message=serv.recv
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break if message==false
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puts message
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serv.send("Got #{message}")
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end
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