IntField_Test.py 文件源码

def test_intfield_with_variable_bit_lenth(self):
        """
        This test verifies that setting an integer value of variable size is correctly exported to the to_bytes 
        function.  This also tests the ability to set a value for the packet upon instantiation.  
        """
        class int_packet_with_varied_sized_int_fields(models.Packet):
            int_field = models.IntField()
            int_field_signed = models.IntField(signed=True)
            int_field_4_bits = models.IntField(bit_len=4)
            int_field_12_bits = models.IntField(bit_len=12)

        pkt = int_packet_with_varied_sized_int_fields(
            int_field = 0xbeef,
            int_field_signed = 0xdead,
            int_field_4_bits = 0xa,
            int_field_12_bits = 0xbc
        )

        class c_pkt_struct(ctypes.Structure):
            _fields_ = (
                ('int_field', ctypes.c_uint16),
                ('int_field_signed', ctypes.c_int16),
                ('int_field_4_bits', ctypes.c_uint16, 4),
                ('int_field_12_bits', ctypes.c_uint16, 12),
            )

        c_pkt = c_pkt_struct()
        c_pkt.int_field = 0xbeef
        c_pkt.int_field_signed = 0xdead
        c_pkt.int_field_4_bits = 0xa
        c_pkt.int_field_12_bits = 0xbc

        b_str = ctypes.string_at(ctypes.addressof(c_pkt), ctypes.sizeof(c_pkt))

        self.assertEquals(b_str, pkt.to_bytes())