虚拟网络转发设备在Linux内核中的设计与实现

Design and Implementation of Virtual Network Transmitting Device in Linux Kernel

目前工业现场总线的工作站通常需要将采集到的实时数据流快速地转发到处理控制系统,以实现对工业设备的实时监控.基于这一应用的需要,把Linux 2.4.6内核在微型化的基础上移植到PC104现场总线工作站,并针对该内核设计实现了虚拟的网络数据转发设备,通过这一虚拟设备可以基本代替实际的转发卡,实现将数据转发到处理控制系统的功能,以节约硬件成本.分析了Linux网络接口对数据流的处理过程,讨论了虚拟网络数据转发设备的设计原理,并给出部分的转发处理函数的实现代码.

At present, the workstation of industrial field bus requires transmit acquired real-time data stream quickly to processing control system so as to realize real-time monitoring over industrial equipment. Based on this requirement, the size of Linux Kernel 2.4.6, is made smaller and is transplanted to PC104 field-bus workstation, and a virtual data transmit device is designed and implemented based on the changed kernel, which can practically replace actual transmitting cards to realize the function of transmitting data to processing control system. Thus, the cost of devices can be saved. This paper analyzes the process of network data flow managed by Linux network interfaces in detail, discusses the design principles of virtual network data transmitting devices, and provides parts of the key implementation codes of transmission processing functions.