test_socket.py 文件源码

def testSingleCmsgTruncInData(self):
        # Test truncation of a control message inside its associated
        # data.  The message may be returned with its data truncated,
        # or not returned at all.
        self.serv_sock.setsockopt(socket.IPPROTO_IPV6,
                                  socket.IPV6_RECVHOPLIMIT, 1)
        self.misc_event.set()
        msg, ancdata, flags, addr = self.doRecvmsg(
            self.serv_sock, len(MSG), socket.CMSG_LEN(SIZEOF_INT) - 1)

        self.assertEqual(msg, MSG)
        self.checkRecvmsgAddress(addr, self.cli_addr)
        self.checkFlags(flags, eor=True, checkset=socket.MSG_CTRUNC)

        self.assertLessEqual(len(ancdata), 1)
        if ancdata:
            cmsg_level, cmsg_type, cmsg_data = ancdata[0]
            self.assertEqual(cmsg_level, socket.IPPROTO_IPV6)
            self.assertEqual(cmsg_type, socket.IPV6_HOPLIMIT)
            self.assertLess(len(cmsg_data), SIZEOF_INT)