import _winreg as reg
import win32file


# path to network adapter registery class
adapter_key = r'SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}'


def get_device_guid():

    with reg.OpenKey(reg.HKEY_LOCAL_MACHINE, adapter_key) as adapters:
        try:
      # enum each key under this register folder, 10000 should be big enough
      # since we don't know how many keys it has
            for i in range(10000):
                key_name = reg.EnumKey(adapters, i)

        # open the regedit machine code
                with reg.OpenKey(adapters, key_name) as adapter:
                    try:

            # get device id of tap-win32 Virtual Network Driver
                        component_id = reg.QueryValueEx(adapter, 'ComponentId')[0]
                        if component_id == 'tap0801':
                            return reg.QueryValueEx(adapter, 'NetCfgInstanceId')[0]
                    except WindowsError:
                            pass
        except WindowsError:
                pass


# return bitwise-formated tap control code in DWORD (int32)
def CTL_CODE(device_type, function, method, access):
    return (device_type << 16) | (access << 14) | (function << 2) | method

def TAP_CONTROL_CODE(request, method):
    return CTL_CODE(34, request, method, 0)


# tap driver config params
TAP_IOCTL_CONFIG_POINT_TO_POINT = TAP_CONTROL_CODE(5, 0)
TAP_IOCTL_SET_MEDIA_STATUS = TAP_CONTROL_CODE(6, 0)
TAP_IOCTL_CONFIG_TUN = TAP_CONTROL_CODE(10, 0)

# Run tap driver in p2p mode
TAP_P2P_MODE = False

if __name__ == '__main__':
    guid = get_device_guid()

  # create tap config file in user mode device dir
    handle = win32file.CreateFile(r'\\.\Global\%s.tap' % guid,
                                                                win32file.GENERIC_READ | win32file.GENERIC_WRITE,
                                                                win32file.FILE_SHARE_READ | win32file.FILE_SHARE_WRITE,
                                                                None, win32file.OPEN_EXISTING,
                                                                win32file.FILE_ATTRIBUTE_SYSTEM, # | win32file.FILE_FLAG_OVERLAPPED,
                                                                None)
  # print target file handle
    print(handle.handle)

    if TAP_P2P_MODE:
        win32file.DeviceIoControl(handle, TAP_IOCTL_CONFIG_POINT_TO_POINT,
                                                            '\xc0\xa8\x11\x01\xc0\xa8\x11\x10', None)
    else:
        win32file.DeviceIoControl(handle, TAP_IOCTL_SET_MEDIA_STATUS, '\x01\x00\x00\x00', None)
        win32file.DeviceIoControl(handle, TAP_IOCTL_CONFIG_TUN,
                                                            '\x0a\x03\x00\x01\x0a\x03\x00\x00\xff\xff\xff\x00', None)
    while True:
        l, p = win32file.ReadFile(handle, 2000)
        q = p[:12] + p[16:20] + p[12:16] + p[20:]
        win32file.WriteFile(handle, q)
        print(p, q)
    win32file.CloseHandle(handle)