is it possible to develop a packet sniffer in android?

I am a computer science student, and need to do a final project in the communication field. I have experience with java but not with development to the android. My prof suggested I should develop a packet sniffer for the android os. I开发者_如何学C know there are some packet sniffing programs, but I saw they require a root access. Does that mean it can't be done via the regular SDK? Does the wifi api (or any other api) allows you to get packets that are not aimed to your phone? can you please tell me how it can be done? (or refer me to something helpul)

Thanks!