Linux内核移动性支持机制与实现

Mechanism of Mobility Support in Linux Kernel and Its Implementation

随着信息技术的高速发展及移动终端的普及,用户期望网络能够在任何时间、任何地点,以任何方式提供信息服务。为了更好地支持移动性,业界提出移动IP、身份位置分离机制、SIP等多种方案。然而,它们都不能同时支持主机移动性和服务移动性。文中提出的移动性支持机制是在Linux内核中,利用一体化网络中的连接标识管理服务,在协议栈中同时支持终端和服务的移动性。首先,提出了两种内核中快速捕获IP地址更新的机制;然后,修改Linux内核中的套接字,实现IP地址改变但连接保持的目标,从而实现移动性;最后通过比较两种机制在实现移动性上的时延,选择了内核通知链机制作为移动性支持机制。

With the rapid development of communication technology and the widespread of portable terminal devices,the users require that the Internet can provide access service at any time,in any location,and by all means. In order to support mobility,the community has proposed a few schemes such as M obile IP,SIP and Identifier/Locator separation. However,none of them can support host mobility and service mobility at the same time. It has proposed a solution to support both host mobility and service mobility in this paper,which is realized by using the CID（ Connection IDentifier） in the universal network to manage connections. Firstly,come up with tw o mechanisms to realize quick access to updated IP addresses in Linux kernel. Secondly,modify the API socket created by the system when a connection is established betw een a client and a server,so that the connection keeps unchanged,regardless of the change of IP addresses. At last,after comparing and analyzing,choose the latter as the support proposal in mobility.