#!/usr/sbin/nft -f flush ruleset define public_if = eth0 define trusted_if = eth1 define voip_if = eth2.10 define guest_if = eth2.20 define home_if = { $trusted_if, $voip_if, $guest_if } define home_ipv6_if = { $trusted_if, $voip_if, $guest_if } define masq_ip = { 192.168.1.0/24, 192.168.2.0/24, 192.168.3.0/24, 192.168.4.0/24 } define masq_if = $public_if define host1_ip = 192.168.1.10 define host2_ip = 192.168.2.20 define host3_ip = 192.168.3.30 define host4_ip = 192.168.4.40 define proxy_port = 8443 define private_ip = { 192.168.0.0/16, 172.16.0.0/12, 10.0.0.0/8 } define private_ip6 = { fe80::/64, fd00::/8 } define bogons_ip = { 0.0.0.0/8, 10.0.0.0/8, 100.64.0.0/10, 127.0.0.0/8, 169.254.0.0/16, 172.16.0.0/12, 192.0.0.0/24, 192.0.2.0/24, 192.168.0.0/16, 198.18.0.0/15, 198.51.100.0/24, 203.0.113.0/24, 224.0.0.0/3 } define bogons_ip6 = { ::/3, 2001:0002::/48, 2001:0003::/32, 2001:10::/28, 2001:20::/28, 2001::/32, 2001:db8::/32, 2002::/16, 3000::/4, 4000::/2, 8000::/1 } define sip_whitelist_ip6 = { 2001:db8::1/128, 2001:db8::2/128 } define smtps_whitelist_ip = 10.0.0.1 define protocol_whitelist = { tcp, udp, icmp, ipv6-icmp } table inet filter { map if_input { type ifname : verdict; elements = { $public_if : jump public_input, $trusted_if : jump home_input, $voip_if : jump home_input, $guest_if : jump home_input } } map if_forward { type ifname : verdict; elements = { $public_if : jump public_forward, $trusted_if : jump trusted_forward, $voip_if : jump voip_forward, $guest_if : jump guest_forward } } map if_output { type ifname : verdict; elements = { $public_if : jump public_output, $trusted_if : jump home_output, $voip_if : jump home_output, $guest_if : jump home_output } } set ipv4_blacklist { type ipv4_addr; flags interval; auto-merge; } set ipv6_blacklist { type ipv6_addr; flags interval; auto-merge; } set limit_src_ip { type ipv4_addr; flags dynamic, timeout; size 1024; } set limit_src_ip6 { type ipv6_addr; flags dynamic, timeout; size 1024; } chain PREROUTING_RAW { type filter hook prerouting priority raw; meta l4proto != $protocol_whitelist counter drop tcp flags syn jump { tcp option maxseg size 1-500 counter drop tcp sport 0 counter drop } rt type 0 counter drop } chain PREROUTING_MANGLE { type filter hook prerouting priority mangle; ct state vmap { invalid : jump ct_invalid_pre, untracked : jump ct_untracked_pre, new : jump ct_new_pre, related : jump rpfilter } } chain ct_invalid_pre { counter drop } chain ct_untracked_pre { icmpv6 type { nd-router-solicit, nd-router-advert, nd-neighbor-solicit, nd-neighbor-advert, mld-listener-query, mld2-listener-report } return counter drop } chain ct_new_pre { jump rpfilter tcp flags & (fin|syn|rst|ack) != syn counter drop iifname $public_if meta nfproto vmap { ipv4 : jump blacklist_input_ipv4, ipv6 : jump blacklist_input_ipv6 } } chain rpfilter { ip saddr 0.0.0.0 ip daddr 255.255.255.255 udp sport bootpc udp dport bootps return ip6 saddr ::/128 ip6 daddr . icmpv6 type { ff02::1:ff00:0/104 . nd-neighbor-solicit, ff02::16 . mld2-listener-report } return fib saddr . iif oif eq 0 counter drop } chain blacklist_input_ipv4{ ip saddr $bogons_ip counter drop ip saddr @ipv4_blacklist counter drop } chain blacklist_input_ipv6{ icmpv6 type { nd-router-solicit, nd-router-advert, nd-neighbor-solicit, nd-neighbor-advert } ip6 saddr fe80::/64 return udp sport dhcpv6-server ip6 saddr fe80::/64 return ip6 saddr $bogons_ip6 counter drop ip6 saddr @ipv6_blacklist counter drop } chain INPUT { type filter hook input priority filter; policy drop; iif lo accept ct state established,related accept iifname vmap @if_input log prefix "NFT REJECT IN " flags ether flags ip options limit rate 5/second burst 10 packets reject } chain public_input { icmpv6 type { nd-router-solicit, nd-router-advert, nd-neighbor-solicit, nd-neighbor-advert } ip6 saddr fe80::/64 ip6 hoplimit 255 accept udp sport dhcpv6-server udp dport dhcpv6-client ip6 saddr fe80::/64 accept fib daddr type { broadcast, multicast, anycast } counter drop counter drop } chain home_input { icmpv6 type { nd-router-solicit, nd-router-advert, nd-neighbor-solicit, nd-neighbor-advert } ip6 hoplimit 255 accept icmpv6 type { mld-listener-query, mld2-listener-report } ip6 hoplimit 1 accept udp sport bootpc udp dport bootps accept udp sport dhcpv6-client udp dport dhcpv6-server iifname $home_ipv6_if accept fib daddr type { broadcast, multicast, anycast } counter drop icmp type echo-request accept icmpv6 type echo-request accept tcp dport ssh iifname $trusted_if accept meta l4proto { tcp, udp } th dport domain jump { ip6 saddr != $private_ip6 counter reject accept } udp dport ntp accept tcp dport $proxy_port accept } chain FORWARD_MANGLE { type filter hook forward priority mangle; oifname $public_if jump { ct state new meta nfproto vmap { ipv4 : jump blacklist_output_ipv4, ipv6 : jump blacklist_output_ipv6 } tcp flags & (syn|rst) == syn tcp option maxseg size set rt mtu } } chain blacklist_output_ipv4 { ip daddr $bogons_ip goto log_blacklist ip daddr @ipv4_blacklist goto log_blacklist } chain blacklist_output_ipv6 { icmpv6 type . ip6 daddr { nd-router-solicit . ff02::2/128, nd-neighbor-solicit . ff02::1:ff00:0/104, nd-neighbor-advert . fe80::/64, nd-neighbor-advert . ff02::1/128, nd-neighbor-advert . ff02::1:ff00:0/104, mld2-listener-report . ff02::16/128 } return udp dport dhcpv6-server ip6 daddr ff02::1:2 return ip6 daddr $bogons_ip6 goto log_blacklist ip6 daddr @ipv6_blacklist goto log_blacklist } chain log_blacklist { log prefix "NFT BLACKLIST " flags ether flags ip options limit rate 5/minute burst 10 packets drop counter drop } chain FORWARD { type filter hook forward priority filter; policy drop; ct state established,related accept fib daddr type { broadcast, multicast, anycast } counter drop iifname vmap @if_forward log prefix "NFT REJECT FWD " flags ether flags ip options limit rate 5/second burst 10 packets reject } chain public_forward { udp dport { sip, 7078-7097 } oifname $voip_if jump { ip6 saddr $sip_whitelist_ip6 accept meta nfproto ipv6 log prefix "NFT DROP SIP " flags ether flags ip options limit rate 5/second burst 10 packets drop } counter drop } chain trusted_forward { oifname $public_if accept icmp type echo-request accept icmpv6 type echo-request accept ip daddr { $host3_ip, $host4_ip } tcp dport vmap { ssh : accept, https : accept, http : drop } ip daddr $host2_ip jump { tcp dport { http, https, printer, ipp, 9100 } accept udp dport snmp accept } } chain voip_forward { icmpv6 type { destination-unreachable, packet-too-big, time-exceeded, parameter-problem, echo-request } oifname $public_if accept ip6 daddr $sip_whitelist_ip6 jump { udp dport { 3478, sip } accept udp sport { 7078-7097 } accept tcp dport sip-tls accept } tcp dport submissions ip daddr $smtps_whitelist_ip accept tcp dport http oifname $public_if counter reject } chain guest_forward { oifname $public_if accept } chain OUTPUT { type filter hook output priority filter; policy drop; oif lo accept ct state vmap { established : accept, related : accept, invalid : jump ct_invalid_out, untracked : jump ct_untracked_out } oifname vmap @if_output log prefix "NFT REJECT OUT " flags ether flags ip options limit rate 5/second burst 10 packets reject } chain ct_invalid_out { counter drop } chain ct_untracked_out { icmpv6 type { nd-router-solicit, nd-router-advert, nd-neighbor-solicit, nd-neighbor-advert, mld-listener-query, mld2-listener-report } return counter drop } chain public_output { ct state new meta nfproto vmap { ipv4 : jump blacklist_output_ipv4, ipv6 : jump blacklist_output_ipv6 } icmp type { destination-unreachable, time-exceeded, parameter-problem, echo-request } accept icmpv6 type { destination-unreachable, packet-too-big, time-exceeded, parameter-problem, echo-request } accept icmpv6 type { nd-router-solicit, nd-router-advert, nd-neighbor-solicit, nd-neighbor-advert } ip6 hoplimit 255 accept icmpv6 type { mld-listener-query, mld2-listener-report } ip6 hoplimit 1 accept udp dport dhcpv6-server ip6 saddr fe80::/64 ip6 daddr ff02::1:2 accept udp dport { domain, ntp } accept tcp dport { https, submissions, domain-s } accept } chain home_output { icmp type { destination-unreachable, time-exceeded, parameter-problem, echo-request } accept icmpv6 type { destination-unreachable, packet-too-big, time-exceeded, parameter-problem, echo-request } accept icmpv6 type { nd-router-solicit, nd-router-advert, nd-neighbor-solicit, nd-neighbor-advert } ip6 hoplimit 255 accept icmpv6 type { mld-listener-query, mld2-listener-report } ip6 hoplimit 1 accept udp sport dhcpv6-server udp dport dhcpv6-client ip6 saddr fe80::/64 oifname $home_ipv6_if accept udp sport bootps udp dport bootpc ip saddr $private_ip accept tcp dport ssh ip daddr $host1_ip accept } chain POSTROUTING_SRCNAT { type nat hook postrouting priority srcnat; meta nfproto ipv4 ip saddr $masq_ip oifname $masq_if masquerade } }