Research And Implementation For In-vehicle ECU Communicating Mechanism Based On IPv6

With the development of automobile industry, the extension for innovation of mechanical structure has drawn to its end already. Neverthless, the people's real need to other advanced function of vehicle is surely endless. Atempting to make its way farword torwards the intelligence and humanization, computer science and electrical engeering would definetly make great contribution to entire automobile industry.By the combination of the vehicle and computer network, it will make it possible for the automible to become more diversify and net-connected in the near future.In the project, an ARM 9 embedded broad servers as hardware platform on which has been integrated CAN module. for encapsulation and resolution of the CAN data frame. Whenever the IPv6 data package arrived at the CAN bus driver, the control command will be resolved and capsulated into CAN data frame to approach specific ECU for actuator's movement,such as on and off in lamps,up and down in vehicle window. The standard serial port, ethernet interface and USB interface have been integrated into the gateway. The serial port is used to connect the GPS receiver. Ethernet is used to connect with navigation center the front of vehicle and USB interface is to provide the prower source for the GPS receiver. The serial port is responsible for transferring the $GPRMC data received from satellite through antenna to gateway. Not wanting to ruin the whole software structure, we adopt multithread technology to collaborate with Linux kernel module programming The thread reads the $GPRMC and puts them into file. Kernel module hooks the IPv6 form the Netfilter frame,then read the $GPRMC data from the file,finally put the them into data field in the IPv6 packet.When the IPv6 returns to the kernel protocol stack,it will be forwarded to the navigation centre,which avoid the kernel panic.We insert UDP header between the IPv4 header and IPv6 header for the UDP port mapping.All the tunnel modules are implemented in the Linux kernel with the characteristic of dynamic load. The tunnel modules are quite independent on any hardware and call the function reserved in network driver interface layer to modify the sk_buff sock buffer for package capulation and resolution. The tunnel has been put into two classes, one is located in gateway being responsible for requsting the connection from the proxy server, and the other is located proxy server that is used to capsulate and resolve the tunnel packet as well as forward the IPv6 packet to the right gateway. IPv6 neighbor discovery (ND) severs as a repalacement for the ARP and RARP in IPv4 protocol. ND locates the right next hip and exact Mac address of destination node by sending IPv6 solicitation message. The destination node will give a reponse by returning back ND advertisement tell his local link address and Mac address.After all these are done,a usual commnucaiton process establishes,then common IPv6 packet could be sent. In the sake of ND, we devise three link lists in the tunnel module:the first one is used to store the IPv4-IPv6 binding information;second one is used to store the virtual subnet IP information including the IPv6 address,IPv4 address,Mac address and UDP port number; the third one is to store the all the ICMPv6 information. When the desitination node sends back the ND advertisement to the tunnel proxy sever, the tunnel moduel looks for the third link list and fills all ICMPv6 information conversely to traverse the wireless IPv4 network.Integrating IPv6 technology and helping in-vehicle communication get used to the next generation is a kind of innovation in the project, which will not only fill the gap in th e industry, but also establish a solid foundation for the popularity and application of next generation in-vehicle communication platform.