adds NetFlow functionality to track and log network traffic information between peers, with features including:
- Flow logging for TCP, UDP, and ICMP traffic
- Integration with connection tracking system
- Resource ID tracking in NetFlow events
- DNS and exit node collection configuration
- Flow API and Redis cache in management
- Memory-based flow storage implementation
- Kernel conntrack counters and userspace counters
- TCP state machine improvements for more accurate tracking
- Migration from net.IP to netip.Addr in the userspace firewall
Some systems don't play nice with a test chain
So we dropped the idea, and instead we check for the filter table
With this check, we might face a case where iptables is selected once and on the
next netbird up/down it will go back to using nftables
