92 lines
3.6 KiB
Python
92 lines
3.6 KiB
Python
import base64
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import hashlib
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import json
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import logging
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logger = logging.getLogger(__name__)
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class WebSocketConnection(object):
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def __init__(self, handler, messageHandler):
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self.handler = handler
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self.messageHandler = messageHandler
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my_headers = self.handler.headers.items()
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my_header_keys = list(map(lambda x:x[0],my_headers))
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h_key_exists = lambda x:my_header_keys.count(x)
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h_value = lambda x:my_headers[my_header_keys.index(x)][1]
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if (not h_key_exists("Upgrade")) or not (h_value("Upgrade")=="websocket") or (not h_key_exists("Sec-WebSocket-Key")):
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raise WebSocketException
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ws_key = h_value("Sec-WebSocket-Key")
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shakey = hashlib.sha1()
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shakey.update("{ws_key}258EAFA5-E914-47DA-95CA-C5AB0DC85B11".format(ws_key = ws_key).encode())
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ws_key_toreturn = base64.b64encode(shakey.digest())
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self.handler.wfile.write("HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: {0}\r\nCQ-CQ-de: HA5KFU\r\n\r\n".format(ws_key_toreturn.decode()).encode())
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def get_header(self, size, opcode):
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ws_first_byte = 0b10000000 | (opcode & 0x0F)
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if (size > 125):
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return bytes([ws_first_byte, 126, (size>>8) & 0xff, size & 0xff])
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else:
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# 256 bytes binary message in a single unmasked frame
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return bytes([ws_first_byte, size])
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def send(self, data):
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# convenience
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if (type(data) == dict):
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# allow_nan = False disallows NaN and Infinty to be encoded. Browser JSON will not parse them anyway.
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data = json.dumps(data, allow_nan = False)
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# string-type messages are sent as text frames
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if (type(data) == str):
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header = self.get_header(len(data), 1)
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self.handler.wfile.write(header + data.encode('utf-8'))
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self.handler.wfile.flush()
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# anything else as binary
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else:
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header = self.get_header(len(data), 2)
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self.handler.wfile.write(header + data)
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self.handler.wfile.flush()
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def read_loop(self):
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open = True
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while (open):
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header = self.handler.rfile.read(2)
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opcode = header[0] & 0x0F
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length = header[1] & 0x7F
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mask = (header[1] & 0x80) >> 7
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if (length == 126):
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header = self.handler.rfile.read(2)
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length = (header[0] << 8) + header[1]
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if (mask):
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masking_key = self.handler.rfile.read(4)
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data = self.handler.rfile.read(length)
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if (mask):
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data = bytes([b ^ masking_key[index % 4] for (index, b) in enumerate(data)])
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if (opcode == 1):
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message = data.decode('utf-8')
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self.messageHandler.handleTextMessage(self, message)
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elif (opcode == 2):
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self.messageHandler.handleBinaryMessage(self, data)
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elif (opcode == 8):
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open = False
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self.messageHandler.handleClose(self)
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else:
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logger.warning("unsupported opcode: {0}".format(opcode))
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def close(self):
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try:
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header = self.get_header(0, 8)
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self.handler.wfile.write(header)
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self.handler.wfile.flush()
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except ValueError:
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logger.exception("while writing close frame:")
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try:
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self.handler.finish()
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self.handler.connection.close()
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except Exception:
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logger.exception("while closing connection:")
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class WebSocketException(Exception):
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pass
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