xtables-monitor
Write firewall rules using templates!
You want to have a firewall on your laptop? You want to have an IPv4/6 server with a single ruleset? You don't want to grow old writing firewall rules and adapting them? Use the power of templates to solve all these problems!
Using xtables-monitor, you can write a single set of rules for both IPv4 and IPv6 and you can effortlessly have your firewall adapt to your environment by referencing current network settings from your ruleset.
Installation
Run setup.py install. It should automatically check for (Python) dependencies and will install the package.
Copy the examples to or create your own templates in /etc/xtables-monitor.
Dependencies
How to write rules
Check the examples directory. xtables-monitor is based on Jinja2 and uses its template mechanism. A more detailed documentation will follow.
How to apply rules
Use the -a command line switch.
How to react to IP address changes
For the moment, you have to install hooks in /etc/network/if-*.d manually or call the execuable yourself. In a future version, xtables-monitor may be able to react to IP address changes automatically.
Example
$ xtm -i 4 examples/lan.xtm*raw
:PREROUTING ACCEPT [1248:1225640]
:OUTPUT ACCEPT [1204:175650]
COMMIT
*nat
:PREROUTING ACCEPT [83:20726]
:POSTROUTING ACCEPT [142:14494]
:OUTPUT ACCEPT [142:14494]
COMMIT
*mangle
:PREROUTING ACCEPT [1248:1225640]
:INPUT ACCEPT [1246:1225576]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [1204:175650]
:POSTROUTING ACCEPT [1211:176396]
COMMIT
*filter
:INPUT DROP [844:1171925]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [788:111247]
[0:0] -A INPUT -i wlan0 -s 192.168.0.2/255.255.255.0 -m comment --comment "XTM:allow-local-wlan0-1" -j ACCEPT
[0:0] -A INPUT -m comment --comment "XTM:reject" -j REJECT
COMMIT