45 lines
No EOL
1.8 KiB
Python
45 lines
No EOL
1.8 KiB
Python
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import socket, zlib
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HOST = "127.0.0.1" # Standard loopback interface address (localhost)
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PORT = 2000 # Port to listen on (non-privileged ports are > 1023)
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def calculate_crc(data):
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# Calculate the CRC32 checksum of the data
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crc = zlib.crc32(data)
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# Convert the CRC32 value to a 4-byte big-endian byte array
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crc_bytes = crc.to_bytes(4, byteorder='big')
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return crc_bytes
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with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
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s.bind((HOST, PORT))
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s.listen()
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while True:
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try:
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conn, addr = s.accept()
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with conn:
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print(f"Connected by {addr}")
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while True:
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data = conn.recv(1024)
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if not data:
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break
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print(f'RECV: {data.hex()} [{len(data)}]')
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if data[0x11] == 0x01:
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pckt = bytearray([0x01])
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pckt.extend([0x00, 0x00, 0x00, 0x00]) # src
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pckt.extend([0x00, 0x00, 0x00, 0xFF]) # dest
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pckt.extend([0x00, 0x00, 0x00, 0x00]) # packet_id
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pckt.extend(data[0x09:0x0D]) # reply_to
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pckt.extend([0x01]) # command
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pckt.extend([0x00, 0x04]) # data_length
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pckt.extend([0x00, 0x00, 0x00, 0xFF])
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# Calculate CRC for the received data
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crc = calculate_crc(pckt)
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# Append the CRC value to the data
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data_with_crc = pckt + crc
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# Send the modified data (with CRC) back to the client
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conn.sendall(data_with_crc)
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print(f'SEND: {data_with_crc.hex()} [{len(data_with_crc)}]')
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except:
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s.close() |