I have an Android host, that has some TCP/IP services installed. These services are intended for use from a number of LAN clients. These services are not safe for facing unfriendly access. The Android host and the clients often travel to different networks, some of which networks are under my influence, some of which networks are not under my influence. As a consequence, the addresses of the Android host and the clients may change. I yet am not prepared to deploy authentication in the application protocols, for various reasons.
Here is the question. I want to have an Android app, can edit firewall rules, to allow access to the services from friendly addresses, and deny access from unfriendly addresses.
I want this firewall app conveniently operate with the phone touchscreen. I want to avoid too much keyboard typing. I for example want to avoid typing excessive iptables(8) boilerplates every time when traveling. Ok is to have saved templates and only modify necessary information.
I want it to keep track of states so transitioning from and to states not let cruft firewall rules pile up.
I think optional feature is to gather information of known clients from mDNS or netbios or MAC addresses. On top of that, alerting whenever such information changes is helpful. I can verify and cherrypick if such information is legit, not can blindly adopt into firewall rules. So this functionality may be implemented in a separate app. Although be off topic, any idea on this separate app?