Android log and modify all HTTP requests

I am wondering what way I can log (sniff) all HTTP requests that are outgoin开发者_运维知识库g and incoming in whole Android and is it possible to modify them during that process or block ?

What libraries should I use ?

You're going to need a rooted phone at least, which basically rules out distributing what you make on the market unfortunately..

With that in mind, take a look at libpcap and iptables :)