版权声明：原创作品，允许转载，转载时请务必以超链接形式标明文章原始出版、作者信息和本声明。否则将追究法律责任。 http://blog.csdn.net/topmvp - topmvp Networked computers are ubiquitous, and are subject to attack, misuse, and abuse. One method to counterac