#!/bin/bash set -e $NFT add table t $NFT add chain t output {type nat hook output priority 0 \; } $NFT add chain t c1 $NFT add rule t c1 masquerade # kernel should return EOPNOTSUPP $NFT add rule t output jump c1 2>/dev/null || exit 0 echo "E: accepted masquerade in output hook" >&2 exit 1