NFTables

apt install nftables
echo 1 > /proc/sys/net/ipv4/ip_forward

nft list ruleset
nft add table nat
nft add chain ip nat prerouting { type nat hook prerouting priority 100 \; }
nft add chain ip nat postrouting { type nat hook postrouting priority 100 \; }
nft add rule nat postrouting masquerade

#portforwarding
nft add rule nat prerouting iif lan1 tcp dport 443 dnat 192.168.0.10:443 # ip needs to be routed to other interface then in-interface (here lan1)

einfache Befehle

nft flush ruleset #alles löschen
nft -f flowoffload.nft #importieren
nft show ruleset #alles anzeigen

einfache struktur

table ip filter {
        chain input {
                type filter hook input priority 0; policy accept;
        }

        chain output {
                type filter hook output priority 0; policy accept;
        }

        chain forward {
                type filter hook forward priority 0; policy accept;
        }
}
table ip nat {
        chain post {
                type nat hook postrouting priority 0; policy accept;
                oifname "wan" masquerade
        }

        chain pre {
                type nat hook prerouting priority 0; policy accept;
        }
}

links

hwnat

https://github.com/frank-w/BPI-R2-4.14/commits/5.12-hnat

ipv6 mangle crasht noch

für hwnat wird eine neuere version der nftables benötigt als in debian buster angeboten wird

https://github.com/frank-w/nftables-bpi

kompiliert: https://drive.google.com/drive/folders/1hajKvqQa96WRrAy52fQX90i59I1s0h-i?usp=sharing

basic IPv4 Ruleset:

flush ruleset
table ip filter {
        flowtable f {
                hook ingress priority filter + 1
                devices = { lan3, lan0, wan }
                flags offload;
        }
        chain input {
                type filter hook input priority filter; policy accept;
        }

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

        chain forward {
                type filter hook forward priority filter; policy accept;
                ip protocol { tcp, udp } flow add @f
        }
}
table ip nat {
        chain post {
                type nat hook postrouting priority filter; policy accept;
                oifname "wan" masquerade
        }

        chain pre {
                type nat hook prerouting priority filter; policy accept;
        }
}

basic v6 Ruleset (crash!):

flush ruleset
table ip6 filter {
        flowtable f {
                hook ingress priority 1
                devices = { lan3, lan0, wan }
                flags offload;
        }
        chain input {
                type filter hook input priority 0; policy accept;
        }

        chain output {
                type filter hook output priority 0; policy accept;
        }

        chain forward {
                type filter hook forward priority 0; policy accept;
                ip6 nexthdr { tcp, udp } flow add @f
        }
}
table ip6 nat {
        chain post {
                type nat hook postrouting priority 0; policy accept;
                oifname "wan" masquerade
        }

        chain pre {
                type nat hook prerouting priority 0; policy accept;
        }
}

testen:

nft -f nft-nat-flowoffload.nft
#vom client traffic generieren
cat /sys/kernel/debug/mtk_ppe/entries

IPV6-Setup

#!/bin/bash
#on main-router:
#ip -6 route add fd00:a2::/64 via fd00:a::12
#ip -6 route add 2001:470:xxxx:a2::/64 via 2001:470:xxxx::12

ip -6 addr add fd00:a::12/64 dev wan                             
ip -6 addr add fd00:a2::12/64 dev lan3

ip -6 addr add 2001:470:xxxx::12/64 dev wan                             
ip -6 addr add 2001:470:xxxx:a2::12/64 dev lan3

sysctl -w net.ipv6.conf.all.forwarding=1