define icmp_protos = { ipv6-icmp, icmp, igmp }

table inet filter {
  limit lim_reject {
    rate over 1000/second burst 1000 packets
  }

  limit lim_icmp_local {
    rate over 50 mbytes/second burst 50 mbytes
  }
  limit lim_icmp_dsl {
    rate over 1400 kbytes/second burst 1400 kbytes
  }


  chain forward {
    type filter hook forward priority filter
    policy drop


    ct state invalid log prefix "drop invalid forward: " counter drop


    iifname lo counter accept

    oifname != dsl meta l4proto $icmp_protos limit name lim_icmp_local counter drop
    oifname dsl meta l4proto $icmp_protos limit name lim_icmp_dsl counter drop
    meta l4proto $icmp_protos counter accept

    iifname eno1 oifname dsl counter accept
    iifname dsl oifname eno1 ct state {established, related} counter accept



    limit name lim_reject log prefix "drop forward: " counter drop
    log prefix "reject forward: " counter
    meta l4proto tcp ct state new counter reject with tcp reset
    ct state new counter reject


    counter
  }

  chain input {
    type filter hook input priority filter
    policy drop


    ct state invalid log prefix "drop invalid input: " counter drop
    

    iifname lo counter accept
    iif != lo ip daddr 127.0.0.1/8 counter reject
    iif != lo ip6 daddr ::1/128 counter reject

    iifname dsl meta l4proto $icmp_protos limit name lim_icmp_dsl counter drop
    iifname != dsl meta l4proto $icmp_protos limit name lim_icmp_local counter drop
    meta l4proto $icmp_protos counter accept

    ct state {established, related} counter accept

    tcp dport 22 counter accept
    meta protocol ip udp dport 51820 counter accept
    udp dport 60000-61000 counter accept

    iifname dsl meta protocol ip6 udp dport 546 udp sport 547 counter accept


    limit name lim_reject log prefix "drop input: " counter drop
    log prefix "reject input: " counter
    meta l4proto tcp ct state new counter reject with tcp reset
    ct state new counter reject


    counter
  }

  chain output {
    type filter hook output priority filter
    policy accept


    oifname lo counter accept

    oifname != dsl meta l4proto $icmp_protos limit name lim_icmp_local counter drop
    oifname dsl meta l4proto $icmp_protos limit name lim_icmp_dsl counter drop
    meta l4proto $icmp_protos counter accept


    counter
  }
}

table ip nat {
  chain postrouting {
    type nat hook postrouting priority srcnat
    policy accept


    oifname dsl counter masquerade


    counter
  }
}

table inet mangle {
  chain postrouting {
    type filter hook postrouting priority mangle
    policy accept


    oifname dsl meta l4proto tcp tcp flags & (syn|rst) == syn counter tcp option maxseg size set rt mtu


    counter
  }
}