C functions to compare incoming MAC Address in Linux network

Under a special configuration, each computer will be equipped with 4(four units) of WLAN cards in it. The WLAN card is meant for a communication with another computer(s). So, if we have 3 sets of such computers, you can imagine that there will be 12 WLAN cards busy "talking" to each other to communicate. The important rule is that the cards that are located inside the same computer **shall not talk** to each other. I would need a function in Linux /net/mac80211 that is doing this job. In conjunction with this, the function shall be communicating with an application through cfg80211 and nl80211 interface. The user-space application shall get the passed encountered-MAC-Address from the kernel and compare with the other residing cards to see if a match occur. The application will return with TRUE or FALSE denoting a match occured and no match found respectively. In short, i would need : 1) A function in /net/mac80211 to pass the HW Address up 2) cfg80211 and nl80211 function for the interface to the application 3) An application that read&store/get&compare WLAN HW Address and send the result back to the kernel. Additional : 1) All in C funtion based on Linux 2.6.x and above 2) Cross-compilable to PowerPC with e300c3 cross-compiler extension