隨著車聯網快速發展，車聯網的安全議題也越來越受關注，而車聯網設備也成為車聯網安全中的一大議題。為了保證可靠且安全的車聯網環境，車聯網的安全測試成為發展中必要的一環。目前，在車聯網測試中主要有兩種，分為實體測試環境及車聯網模擬器測試。然而，建立一個有效且經濟實惠是有相當的挑戰性。建立一個實體測試環境費用相當昂貴，而車聯網模擬器測試雖然在建置上相對實體測試環境便宜很多，但模擬器的測試結果往往有不夠真實的問題，總結來說兩種測試環境都有其成本或真實性的問題。

為了去解決實體測試環境及模擬器測試的問題，我們提出一個整合實體測試與模擬器測試的系統，此系統提供將模擬器封包送至實體車聯網設備做實體傳輸，透過系統的實體傳輸，我們可以解決模擬器測試真實性的問題。最後我們會將封包再傳回模擬器當中，觀察接收封包後，車輛在模擬器中的行為。在實作系統方面，我們實作OMNeT++介面，使模擬器的network stack與Linux network namespace連接，並使用Raw Socket傳送模擬器封包至實體車聯網設備。最後將送至實體車聯網設備的封包送回模擬器之中，透過以上的流程，我們完成一個相對便宜且真實的測試系統。

With the rapid development of the Vehicle-to-everything network (V2X), the issue of V2X security is gaining more and more attention. The security of V2X devices has become a big issue for the V2X. To ensure reliable security in the V2X, security testing of vehicle devices has become an essential part of vehicle network development. There are mainly two types of vehicle network testing environments, physical testing environment and vehicle network simulator testing. However, building an effective and cheap testing environment is challenging. In a physical testing environment, it is expensive to build a real environment. In vehicle network simulator testing, although it is cheap compared with the physical testing environment, the realisticity is the problem. Both approaches have their cost and realisticity issues.

To improve the limitations of the physical testing environment and vehicle network simulator testing, we propose a system that combines physical transmission and simulator. This system allows packets sent from the vehicle network simulator to the physical vehicle devices. With the system, we can solve the issue of insufficient realisticity for the vehicle network simulator testing by transmission through physical wireless transmission. For the physical testing environment, by sending the physical packets back to the simulator, we can simulate the behavior of vehicles receiving the packets in the simulator without the need for actual vehicles. For the system implementation, we implement the OMNeTT++ interface to connect the simulator network stack with the Linux network namespace and raw sockets for sending packets to the physical device. By configuring the Linux netfilter, we manage the packet transmission direction. Sending from the simulator to the physical vehicle devices and sending back to the simulator from physical vehicle devices. With the above step, we provide a relatively cheap and realistic test system.

[1] C. Sommer, R. German, and F. Dressler, “Bidirectionally Coupled Network and Road
Traffic Simulation for Improved IVC Analysis,” IEEE Transactions on Mobile Com-
puting (TMC), vol. 10, pp. 3–15, January 2011.
[2] D. Krajzewicz, J. Erdmann, M. Behrisch, and L. Bieker, “Recent development and ap-
plications of sumo-simulation of urban mobility,” International journal on advances
in systems and measurements, vol. 5, no. 3&4, 2012.
[3] A. Varga and R. Hornig, “An overview of the omnet++ simulation environment,” in
1st International ICST Conference on Simulation Tools and Techniques for Commu-
nications, Networks and Systems, 2010