ProMix: Linux Promiscuous Wireless Packet Analysis

Wireless packet capture is possible due to the nature of the transmission medium involved in wireless networks. All traffic is distributed within the same frequency band and often times the same channel within the same network. If not, channel hopping is accomplished easily enough as there are a limited number of channels available. As all the packets traveling in both directions between their source and destination are broadcast, any host with wireless capability can intercept and possibly decode any packet it chooses. Network interface cards (NIC) have several modes of operation including their usual mode intuitively dubbed "normal" as well as the potentially devious mode of "promiscuous". Wireless cards have an additional "monitor" mode allowing the host employing them to act much like a scanner. Linux provides a unique and conducive environment to both packet capture and software development given its open source nature. This packet analyzer takes advantage of both the Linux environment and its open source software. jNetPcap is a library for capturing and sending network packets. Using this library, we developed an application to capture packets from a network interface.