R4S OpenWRT 防火墙自定义规则默认值

不小心编辑错了规则导致无法上网，留个作为备忘。

iptables -t nat -A PREROUTING -p udp --dport 53 -j REDIRECT --to-ports 53
iptables -t nat -A PREROUTING -p tcp --dport 53 -j REDIRECT --to-ports 53
[ -n "$(command -v ip6tables)" ] && ip6tables -t nat -A PREROUTING -p udp --dport 53 -j REDIRECT --to-ports 53
[ -n "$(command -v ip6tables)" ] && ip6tables -t nat -A PREROUTING -p tcp --dport 53 -j REDIRECT --to-ports 53