Research And Implementation Of WinPcap-based Software Testing System

In the process of designing and developing software and hardware products, the development cycle of hardware design and development is time-consuming, while efficiency is significantly achieved in software design. Confined by hardware's long cycle, the advantage of time-efficient software design can't be accomplished due to the combination of the two processes, the debugging is postponed. And the increasing of simulations and codes used by device bring about the incompetence of precise positioning and debugging. The emergence of simulation device can solve these problems.The thesis analyses the advantage and disadvantage of multiple packet capture techniques and then chooses the WinPcap for our research. The relative contents of WinPcap, the philosophy of its kernel, BPF filtering, the algorithm of data packet filtering, the increasing of data packet capture rate and the removing of irrelevant data packet is illustrated.In order to test the device and the simulation device simultaneously thus achieve the hybrid networking between device and simulation device, a WinPcap-based synchronization testing system is proposed. This system utilizes the WinPcap's packet capture technique to capture the data packets which transmit from PC to device through network. The problem of data packets retransmitting at the TCP layer is solved by using the relationship between TCP's serial number to filter the retransmitted. Finally, the filtered data packets are used for input to communicate with simulation device, analog device and PC. The feedback information from simulation device is saved in log which can be easily checked to get running status of device so as to debugging and solve the malfunction.The practical results show that the WinPcap-based synchronization testing system is functionally well and stable, and also has good expandability and practical value.