Design And Implementation Of Instant Messenger Message Monitor System On High-speed Network

The Instant Messenger brings people a lot of convenience. It also imperils the nation and society's security, since the IMs make the spreading of reaction and eroticism information easier. Therefore, designing of instant messenger message monitor system is important to our national network and information security. The main work and results of this paper are followed:(1) Based on the IMPP model, the communication process of Instant Messenger is analyzed and the textual formats of IMs are given by the analysis of the captured raw packet.(2) The processing and blocking method on Windows platform is analyzed, especially the NDIS network driver technology. The packet capturing, detecting, analyzing and blocking module is designed and implemented in Windows XP kernel.(3) By analyzing the characteristic of packet arriving and the processing, four considerations in packet capture system design are proposed, and an implementation of a ring buffer based on the four considerations is given.(4) The string match algorithms are studied, and BM algorithm is implemented in the monitor system..Finally, we integrate all theories and technologies, and complete the Instant Messenger message system on high speed network, with good performance.