原始套接字实现Ping命令

原始套接字实现Ping命令：

http://blog.youkuaiyun.com/kzm2008/article/details/5372834

http://blog.youkuaiyun.com/l_yangliu/article/details/7086256

http://www.cnblogs.com/pengdonglin137/archive/2013/03/18/2966683.html

http://www.cnblogs.com/lidabo/archive/2012/07/11/2586932.html

http://blog.chinaunix.net/uid-28455968-id-4138873.html

http://blog.chinaunix.net/uid-21757287-id-194935.html

http://blog.youkuaiyun.com/hansel/article/details/4045867

http://blog.youkuaiyun.com/chary8088/article/details/2486377