#!/usr/sbin/nft -f

flush ruleset

table inet filter {
    set cluster {
        type ipv4_addr; flags interval; auto-merge
        elements = {
{{ nodes | map('device_address') | flatten | selectattr('family.value', '==', 4) | map(attribute='address') | join(',\n') | indent(12, first=True) }}
        }
    }
    set cluster/6 {
        type ipv6_addr; flags interval; auto-merge
        elements = {
{{ nodes | map('device_address') | flatten | selectattr('family.value', '==', 6) | map(attribute='address') | join(',\n') | indent(12, first=True) }}
        }
    }

    # Just a temporary filter until we get our shit together policy-wise.
    set allowed {
        type ipv4_addr; flags interval
        elements = { 10.32.0.0/14, 193.2.76.176/24, 192.168.251.0/24, 88.200.23.0/24 }
    }
    set allowed/6 {
        type ipv6_addr; flags interval
        elements = { 2001:1470:fffd:3432::/64, 2001:1470:fffd:a000::/64 }
    }

    chain input {
        type filter hook input priority filter; policy drop

        ct state vmap { invalid : drop, established : accept, related : accept }
        iif lo accept

        ip protocol icmp icmp type {
            echo-request, echo-reply, destination-unreachable,
            parameter-problem, time-exceeded,
        } accept comment "accept some ICMPv4"

        ip6 nexthdr icmpv6 icmpv6 type {
            echo-request, echo-reply, destination-unreachable,
            packet-too-big, parameter-problem, time-exceeded,
        } accept comment "accept some ICMPv6"

        # BGP / BFD sessions
        iif lan0 ip6 saddr fe80::/64 accept
        iif lan1 ip6 saddr fe80::/64 accept

        iif mgmt accept comment "management access"

        ip saddr @cluster accept comment "accept connections from other nodes"
        ip6 saddr @cluster/6 accept comment "accept connections from other nodes"

        ip saddr @allowed accept
        ip6 saddr @allowed/6 accept
    }

    chain forward {
        type filter hook forward priority filter; policy accept
    }

    chain output {
        type filter hook output priority filter; policy accept
    }
}