Symbian OS-based Smart Phones Firewall Design And Implementation

Along with the increasing popularity of smartphones, they are more widely being used in many fields. At the same time, threats to wireless devices are increasing dramatically. Also, it is known that Symbian OS powers the world's most popular smartphones, so the research of safety protection against smartphones based on Symbian OS platform has the universal meaning. Based on this background, the author proposed the subject about development of firewall on Symbian smartphones.The subject was somewhat forward-looking because when the author addressed this subject, the domestic and overseas researches in this field were both limited in the range of calls firewall, short message firewall and anti-virus firewall, etc. Otherwise, research on smartphones firewall that can be used to control access to internet had not been launched yet untill then.In the thesis, the author decieded using Client/Server mechanism of Symbian OS to design the system's architecture through complete understanding of the features of Symbian OS itself and the key technologies used to develop application under Symbian OS environment.The work the author has done is following:1. Make a careful and detailed plan and design, according to the normal feature of firewall and the constraints and restrictions of smart devices. Real-time monitoring, protocol analyzing and rule matching are the core components and can also work well without user's operation, so they are designed as the server that runs in the background of OS. The management modules, such as rule management, system setting, log management, etc, need to interoperate with user, so they are designed as the client of the system.2. Determine the content of communications between client and server after functional requirements analyzing, design the communication mechanism, and protocol under the architecture of client/server and implement the communication between the real-time monitoring and system management that will be in two different processes.3. Optimize structures of rule file, log file and system setting file, do not use the descriptor that can occupy much more space in file, and store the value of boolean field as a bit value.4. Design every module in detail and complete the implementation of the system.This thesis is also a partial summary of the firewall project, and can give some useful instruction and reference to the developers who want to touch the Symbian application.