78 lines
2.7 KiB
Python
78 lines
2.7 KiB
Python
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import struct
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class VdesMessageUnpack:
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"""VDES消息解包工具类"""
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def __init__(self):
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self.message_frames = []
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self.current_message = b''
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self.is_receiving = False
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self.is_unpacked = False #是否解析到结束帧
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self.MMSI: int
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def unpack_tcp_packet(self, packet_data):
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"""解包TCP协议报文"""
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# 检查帧头
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if packet_data[:4] != b'####':
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raise ValueError("无效的报文帧头")
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# 解析报文类型和长度
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packet_type = struct.unpack('>I', packet_data[4:8])[0]
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packet_length = struct.unpack('>I', packet_data[8:12])[0]
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packet_content = packet_data[12:]
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# 处理不同类型的帧
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if packet_type == 10: # 消息帧
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# print(f"消息帧内容: {packet_content.hex()}")
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frame_type, message = self._process_message_frame(packet_content)
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else:
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print(f"忽略未知报文类型: {packet_type}")
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return None, None
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return frame_type, message
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def _process_message_frame(self, content):
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"""处理消息帧内容"""
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# 解析帧类型(1字节)
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frame_type = struct.unpack('>B', content[:1])[0]
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# print(f"帧类型: {frame_type}")
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if frame_type == 0: # 起始帧
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self.is_receiving = True
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self.current_message = b''
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# 解析目标MMSI和优先级
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target_mmsi = struct.unpack('>I', content[1:5])[0]
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priority = struct.unpack('>B', content[5:6])[0]
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self.MMSI = target_mmsi
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# print(f"开始接收消息，目标MMSI: {target_mmsi}, 优先级: {priority}")
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elif frame_type == 1: # 中间帧
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if self.is_receiving:
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self.current_message = content[1:]
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# print(f"接收中间帧，{self.current_message}")
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elif frame_type == 2: # 结束帧
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if self.is_receiving:
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self.current_message = b''
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# self.message_frames.append(self.current_message)
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self.is_receiving = False
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# print(f"消息接收完成，总长度: {len(self.current_message)}字节")
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else:
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print(f"忽略未知帧类型: {frame_type}")
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return frame_type, self.current_message
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def get_unpack_statu(self):
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"""获取解包状态"""
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return self.is_receiving
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def get_message_frames(self):
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"""获取解包后的消息帧列表"""
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return self.message_frames
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def get_mmsi(self):
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"""获取解包后的消息帧列表"""
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return self.MMSI
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