Right at the moment I am taking a closer look to the polipo proxy software. I already managed to setup an easy socks5 proxy with basic user authentication.
All it needs to be finished is to change the listening interface from eth0 to ppp0. Sadly polipo documentation doesn't provide any detail about this task.
The operating system is Debian 8 running in Hyper-V.
Can this configuration somehow be accomplished, either through calling parameters or configuration file or even iptables?