CAN总线速度转换器

┌──(kali㉿z3r0)-[/media/sf_shared_kali/ncl doc/scanningrecon]
└─$ tshark -r canid589.pcap -t fields -e data.data > data_speed.txt

def format_hex_value(hex_value):
    # Tshark exported specific packets to column data.data unformatted.
    return ' '.join(hex_value[i:i+2] for i in range(0, len(hex_value), 2))

def calculate_speed_from_hex_value(hex_value):
    # 5 byte check 
    if len(hex_value) < 10:
        raise ValueError("Hex value must have at least 10 characters for 5 bytes")

    # Extract the relevant bytes from payload (the last two bytes)
    high_byte = int(hex_value[-4:-2], 16)  
    low_byte = int(hex_value[-2:], 16)

    speed = (high_byte << 8) + low_byte  
    # Example: 00 00 00 04 e1 - (04 << 8) + e1 = 1024 + 225 = 1249

    # Convert speed from centi-KPH to KPH then to MPH
    speed_kph = speed / 100.0  # Assuming the value is in centi-KPH
    speed_mph = speed_kph * 0.621371  # Convert KPH to MPH

    return speed_mph

def main():
    speeds = []

    with open('data_speed.txt', 'r') as file:
        for line in file:
            hex_value = line.strip() 

            if hex_value:  

                formatted_hex_value = format_hex_value(hex_value)
                print(f"Formatted Hex Value: {formatted_hex_value}")  

                try:
                    # Calculate speed and store it in the speeds list
                    speed_mph = calculate_speed_from_hex_value(hex_value)
                    speeds.append(speed_mph)
                    print(f"Calculated Speed: {speed_mph:.2f} MPH")
                except ValueError as e:
                    print(f"Error processing value '{hex_value}': {e}")


    speeds.sort() 
    #Sort lowest to highest

    print("\nFinal Sorted Speeds (MPH):")
    for speed in speeds:
        print(f"{speed:.2f} MPH")

if __name__ == "__main__":
    main()