Add a default firewall rule to allow netbird traffic to be handled
by the access control managers.
Userspace manager behavior:
- When running on Windows, a default rule is add on Windows firewall
- For Linux, we are using one of the Kernel managers to add a single rule
- This PR doesn't handle macOS
Kernel manager behavior:
- For NFtables, if there is a filter table, an INPUT rule is added
- Iptables follows the previous flow if running on kernel mode. If running
on userspace mode, it adds a single rule for INPUT and OUTPUT chains
A new checkerFW package has been introduced to consolidate checks across
route and access control managers.
It supports a new environment variable to skip nftables and allow iptables tests
* Optimize rules with All groups
* Use IP sets in ACLs (nftables implementation)
* Fix squash rule when we receive optimized rules list from management
Works only with userspace implementation:
1. Configure host to solve DNS requests via a fake DSN server address in the Netbird network.
2. Add to firewall catch rule for these DNS requests.
3. Resolve these DNS requests and respond by writing directly to wireguard device.
* Extend protocol and firewall manager to handle old management
* Send correct empty firewall rules list when delete peer
* Add extra tests for firewall manager and uspfilter
* Work with inconsistent state
* Review note
* Update comment
