实现端口转发功能，经测试，ssh、http可以正常使用

prot_codec.py

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+
+import os
+import sys
+import json
+
+
+
+
+# 数据包编解码
+
+
+
+
+
+
+
+# 计算整个数据流的CRC
+def _crc16(data:bytearray):
+  lenth=len(data)
+  if(lenth>0):
+    crc=0xffff
+    for i in range(lenth):
+      crc=(crc^data[i])&0xffff
+      for j in range(8):
+        if(crc&1)!=0:
+          crc=((crc>>1)^0xa001)&0xffff
+        else:
+          crc=(crc>>1)&0xffff
+    return bytearray([crc&0xff,(crc>>8)&0xff])
+  return bytearray([0,0])
+
+
+# 0xff帧起始，0xfe帧结尾
+# 0xf0转义标识
+# 0xf1命令数据分割
+# 0xf2数据校验分割
+
+# 字节数据大于等于0xf0 之后要转义
+def _tran(data:bytearray):
+  ret=bytearray()
+  for item in data:
+    if(item>=0xf0):
+      ret.append(0xf0)
+      ret.append(item-0xf0)
+    else:
+      ret.append(item)
+  return ret
+
+# 去转义
+def _untran(data:bytearray):
+  ret=bytearray()
+  i=0
+  length=len(data)
+  while i<length:
+    if(data[i]>=0xf0):
+      ret.append(data[i]+data[i+1])
+      i+=1
+    else:
+      ret.append(data[i])
+    i+=1
+  return ret
+
+
+# 以命令和数据编码
+def encode(cmd:bytearray,data:bytearray):
+  crc=_crc16(cmd+data)
+  ret=bytearray()
+  ret.append(0xff)
+  ret+=_tran(cmd)
+  ret.append(0xf1)
+  ret+=_tran(data)
+  ret.append(0xf2)
+  ret+=_tran(crc)
+  ret.append(0xfe)
+  return ret
+
+
+# 解码为命令和数据
+def decode(data:bytearray):
+  # print('prot_decode:',data.hex(' '))
+  while len(data)>0:
+    if(data[0]!=0xff):
+      data=data[1:]
+    else:
+      break
+  if(len(data)==0):
+    return (None,None)
+  if(data[0]==0xff and data[-1]==0xfe):
+    data=data[1:-1]
+    cmd_index=data.find(0xf1)
+    data_index=data.find(0xf2)
+    cmd=_untran(data[:cmd_index])
+    da=_untran(data[cmd_index+1:data_index])
+    crc=_untran(data[data_index+1:])
+    if(crc==_crc16(cmd+da)):
+      return (cmd,da)
+  return (None,None)
+
+
+
+
+
+
+
+
+if __name__ == "__main__":
+  data=encode(json.dumps({'device':'client','option':'data'}).encode('utf-8'),bytearray([0xff,0xfd,0xff,0xde,0xde]))
+  print(data.hex(' '))
+  print(decode(data))
+  print(b'\xff'.hex(' '))
+
+
+
+