* Allow to configure firewall rules from the GUI (WIP)
New features:
- Configure and list system firewall rules from the GUI (nftables).
- Configure chains' policies.
- Add simple rules to allow incoming ports.
- Add simple rules to exclude apps (ports) from being intercepted.
This feature is only available for nftables. iptables is still supported,
you can add rules to the configuration file and they'll be loaded, but
you can't configure them from the GUI.
More information: #592
Added option to let the users define iptables rules.
The system rules are added in the file /etc/opensnitchd/system-fw.json
with this format:
```
{
"SystemRules": [
{
"Rule": {
"Description": "Allow pptp VPN",
"Table": "mangle",
"Chain": "OUTPUT",
"Parameters": "-p gre",
"Target": "ACCEPT",
"TargetParameters": ""
}
}
]
}
```
On the mangle table, OUTPUT chain, these rules are added before
the NFQUEUE interception rule, so any rule you add there bypasses the
interception. Useful to allow traffic you don't want to intercept.
This feature solves in some way the issue some users have connecting to
VPNs when the Default Action configured in the daemon is Deny.
For example:
- OpenVPN when keepalive is configured and ICMP is used.
- PPTP because the GRE routing protocol is blocked.
- probably others like IPSEC.
(regarding WireGuard, as far as I can tell it works just fine, see #61).
closes#47
