68 lines
1.9 KiB
Python
68 lines
1.9 KiB
Python
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import socket
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import struct
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import zlib
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import io
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from time import time
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import config
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class CRAPClient:
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def __init__(self, ip='127.0.0.1', port=1337):
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self.ip, self.port = ip, port
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self.sock = socket.Socket(socket.AF_INET, socket.SOCK_DGRAM)
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self.close = self.sock.close
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def sendframe(self, frame):
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self.sock.sendto(frame, (self.ip, self.port))
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def _timestamped_recv(sock):
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while True:
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try:
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data, addr = sock.recvfrom(config.frame_size*3+4)
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except io.BlockingIOError as e:
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raise StopIteration()
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else:
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yield time(), data, addr
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class CRAPServer:
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def __init__(self, ip='', port=1337, blocking=False, log=print):
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self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
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self.sock.setblocking(blocking)
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self.sock.bind((ip, port))
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self.current_client = None
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self.last_timestamp = 0
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self.begin_timestamp = 0
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self.log = log
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def close(self):
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self.sock.close()
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def __iter__(self):
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for timestamp, data, (addr, sport) in _timestamped_recv(self.sock):
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if data is None:
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yield None
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if timestamp - self.last_timestamp > config.udp_timeout\
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or timestamp - self.begin_timestamp > config.udp_switch_interval:
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self.current_client = addr
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self.begin_timestamp = timestamp
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self.log('\x1B[91mAccepting UDP data from\x1B[0m', addr)
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if addr == self.current_client:
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if len(data) == config.frame_size*3+4:
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(crc1,), crc2 = struct.unpack('!I', data[-4:]), zlib.crc32(data, 0),
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data = data[:-4] # crop CRC
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if crc1 and crc1 != crc2: # crc1 zero-check for backward-compatibility
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self.log('Error receiving UDP frame: Invalid frame CRC checksum: Expected {}, got {}'.format(crc2, crc1))
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continue
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elif len(data) != config.frame_size*3:
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self.log('Error receiving UDP frame: Invalid frame size: {}'.format(len(data)))
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self.last_timestamp = timestamp
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yield data
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