(OpenWrt) /etc/config/shadowsocks && /etc/init.d/ss-tunnel

shadowsocks

config port_forward 'world'
	option local_port '5300'
	option destination '8.8.4.4:53'
	option mtu '1492'
	list server 'nil'

config port_forward 'china'
	option protocol 'udp'
	option local_port '5353'
	option destination '223.5.5.5:53'
	option mtu '1492'
	list server 'nil'

ss-tunnel

#!/bin/sh /etc/rc.common
# Copyright (C) 2023 EasyPi Software Foundation

# start after and stop before shadowsocks
START=91
STOP=14
PIDCOUNT=0

USE_PROCD=1
PROG=/usr/bin/ss-tunnel
NAME=ss-tunnel
SERVER=hk

validate_section_port_forward()
{
	uci_validate_section shadowsocks port_forward "${1}" \
		'protocol:or("tcp", "udp", "both"):both' \
		'local_port:port' \
		'destination:string' \
		'mtu:uinteger'
}

port_forward_instance()
{
	local local_port destination mtu

	validate_section_port_forward "${1}" || {
		echo "validation failed"
		return 1
	}

	PIDCOUNT="$(( ${PIDCOUNT} + 1))"

	procd_open_instance
	procd_set_param command "${PROG}" -c /var/etc/shadowsocks.${SERVER}.json --no-delay
	[ -n "${local_port}" ] && procd_append_param command -l "${local_port}"
	[ -n "${destination}" ] && procd_append_param command -L "${destination}"
	[ -n "${mtu}" ] && procd_append_param command --mtu "${mtu}"
	case "${protocol}" in
		"both") procd_append_param command -u;;
		"udp") procd_append_param command -U;;
		"tcp") ;;
	esac
	procd_set_param pidfile /var/run/${NAME}-${PIDCOUNT}.pid
	procd_set_param respawn
	procd_close_instance
}

start_service()
{
	config_load "shadowsocks"
	config_foreach port_forward_instance port_forward
}