#!/bin/sh
#
# Copyright (C) 2017 openwrt-ssr
# Copyright (C) 2017 yushi studio <ywb94@qq.com>
#
# This is free software, licensed under the GNU General Public License v3.
# See /LICENSE for more information.
#

# Detect firewall version and set appropriate tools
detect_firewall() {
	if command -v nft >/dev/null 2>&1 && \
		[ -n "$(uci get firewall.@defaults[0].syn_flood 2>/dev/null)" ] && \
		! grep -q "fw3" /etc/init.d/firewall 2>/dev/null; then
			USE_NFT=1  
			NFT="nft"
			FWI=$(uci get firewall.shadowsocksr.path 2>/dev/null)  # firewall include file
	else
		USE_NFT=0
		IPT="iptables -t nat"                                 # alias of iptables
		FWI=$(uci get firewall.shadowsocksr.path 2>/dev/null) # firewall include file
	fi
}

# Initialize firewall detection
detect_firewall

TAG="_SS_SPEC_RULE_"                                  # comment tag

usage() {
	cat <<-EOF
		Usage: ssr-rules [options]

		Valid options are:

		    -s <server_ip>          ip address of shadowsocksr remote server
		    -l <local_port>         port number of shadowsocksr local server
		    -S <server_ip>          ip address of shadowsocksr remote UDP server
		    -L <local_port>         port number of shadowsocksr local UDP server
		    -i <ip_list_file>       a file content is bypassed ip list
		    -a <lan_ips>            lan ip of access control, need a prefix to
		                            define access control mode
		    -b <wan_ips>            wan ip of will be bypassed
		    -w <wan_ips>            wan ip of will be forwarded
		    -B <bp_lan_ips>         lan ip of will be bypassed proxy
		    -p <fp_lan_ips>         lan ip of will be global proxy
		    -G <gm_lan_ips>         lan ip of will be game mode proxy
		    -D <proxy_ports>        proxy ports
		    -F                      shunt mode
		    -N                      shunt server IP
		    -M                      shunt proxy mode
		    -m <Interface>          Interface name
		    -I <ip_list_file>       a file content is bypassed shunt ip list
		    -e <extra_options>      extra options for iptables
		    -o                      apply the rules to the OUTPUT chain
		    -O                      apply the global rules to the OUTPUT chain
		    -u                      enable udprelay mode, TPROXY is required
		    -U                      enable udprelay mode, using different IP
		                            and ports for TCP and UDP
		    -f                      flush the rules
		    -g                      gfwlist mode
		    -r                      router mode
		    -c                      oversea mode
		    -z                      all mode
		    -h                      show this help message and exit
	EOF
	exit $1
}

loger() {
	# 1.alert 2.crit 3.err 4.warn 5.notice 6.info 7.debug
	logger -st ssr-rules[$$] -p$1 $2
}

flush_r() {
	if [ "$USE_NFT" = "1" ]; then
		flush_nftables
	else
		flush_iptables_legacy
	fi
	return 0
}

flush_nftables() {
	# 删除 inet ss_spec 表
	if $NFT list table inet ss_spec >/dev/null 2>&1; then
		# 删除所有链
		local CHAINS=$($NFT list table inet ss_spec | awk '/chain [a-zA-Z0-9_-]+/ {print $2}' | sort -u)
		for chain in $CHAINS; do
			$NFT flush chain inet ss_spec $chain 2>/dev/null
			$NFT delete chain inet ss_spec $chain 2>/dev/null
		done

		# 删除所有集合（set）
		local SETS=$($NFT list table inet ss_spec | awk '/set [a-zA-Z0-9_-]+/ {print $2}' | sort -u)
		for setname in $SETS; do
			$NFT flush set inet ss_spec $setname 2>/dev/null
			$NFT delete set inet ss_spec $setname 2>/dev/null
		done

		# 删除整个表
		$NFT delete table inet ss_spec 2>/dev/null
	fi

	# 删除 ip ss_spec_mangle 表（如果存在）
	if $NFT list table ip ss_spec_mangle >/dev/null 2>&1; then
		# 删除所有链
		local CHAINS=$($NFT list table ip ss_spec_mangle | awk '/chain [a-zA-Z0-9_-]+/ {print $2}' | sort -u)
		for chain in $CHAINS; do
			$NFT flush chain ip ss_spec_mangle $chain 2>/dev/null
			$NFT delete chain ip ss_spec_mangle $chain 2>/dev/null
		done

		# 删除所有集合（set）
		local SETS=$($NFT list table ip ss_spec_mangle | awk '/set [a-zA-Z0-9_-]+/ {print $2}' | sort -u)
		for setname in $SETS; do
			$NFT flush set ip ss_spec_mangle $setname 2>/dev/null
			$NFT delete set ip ss_spec_mangle $setname 2>/dev/null
		done

		# 删除整个表
		$NFT delete table ip ss_spec_mangle 2>/dev/null
	fi

	# 删除策略路由标记规则
	ip rule del fwmark 0x01/0x01 table 100 2>/dev/null
	ip route del local 0.0.0.0/0 dev lo table 100 2>/dev/null

	# 可选：强制删除所有 ss_spec 相关的集合（即使表被误删）
	for setname in ss_spec_lan_ac ss_spec_wan_ac ssr_gen_router fplan bplan gmlan oversea whitelist blacklist netflix gfwlist china music; do
		$NFT delete set inet ss_spec $setname 2>/dev/null
		$NFT delete set ip ss_spec_mangle $setname 2>/dev/null
	done

	# 重置防火墙 include 文件
	[ -n "$FWI" ] && echo '#!/bin/sh' >"$FWI"

	return 0
}

flush_iptables_legacy() {
	flush_iptables() {
		local ipt="iptables -t $1"
		local DAT=$(iptables-save -t $1)
		eval $(echo "$DAT" | grep "$TAG" | sed -e 's/^-A/$ipt -D/' -e 's/$/;/')
		for chain in $(echo "$DAT" | awk '/^:SS_SPEC/{print $1}'); do
			$ipt -F ${chain:1} 2>/dev/null && $ipt -X ${chain:1}
		done
	}
	flush_iptables nat
	flush_iptables mangle
	ip rule del fwmark 0x01/0x01 table 100 2>/dev/null
	ip route del local 0.0.0.0/0 dev lo table 100 2>/dev/null
	ipset -X ss_spec_lan_ac 2>/dev/null
	ipset -X ss_spec_wan_ac 2>/dev/null
	ipset -X ssr_gen_router 2>/dev/null
	ipset -X fplan 2>/dev/null
	ipset -X bplan 2>/dev/null
	ipset -X gmlan 2>/dev/null
	ipset -X oversea 2>/dev/null
	ipset -X whitelist 2>/dev/null
	ipset -X blacklist 2>/dev/null
	ipset -X netflix 2>/dev/null
	[ -n "$FWI" ] && echo '#!/bin/sh' >$FWI
	return 0
}

ipset_r() {
	if [ "$USE_NFT" = "1" ]; then
		ipset_nft
	else
		ipset_iptables
	fi
	return $?
}

ipset_nft() {
	# Create nftables table and sets
	if ! $NFT list table inet ss_spec >/dev/null 2>&1; then
		$NFT add table inet ss_spec 2>/dev/null
	fi

	# Create necessary collections
	for setname in ss_spec_wan_ac china gmlan fplan bplan whitelist blacklist netflix; do
		if ! $NFT list set inet ss_spec $setname >/dev/null 2>&1; then
        	$NFT add set inet ss_spec $setname '{ type ipv4_addr; flags interval; auto-merge; }' 2>/dev/null
		else
        	$NFT flush set inet ss_spec $setname 2>/dev/null
		fi
    done

	# 批量导入中国IP列表
	if [ -f "${china_ip:=/etc/ssrplus/china_ssr.txt}" ]; then
		$NFT add element inet ss_spec china { $(tr '\n' ',' < "${china_ip}" | sed 's/,$//') } 2>/dev/null
	fi

    # Add IP addresses to sets
    for ip in $LAN_GM_IP; do 
		[ -n "$ip" ] && $NFT add element inet ss_spec gmlan "{ $ip }" 2>/dev/null
    done
    for ip in $LAN_FP_IP; do 
 		[ -n "$ip" ] && $NFT add element inet ss_spec fplan "{ $ip }" 2>/dev/null
    done
    for ip in $LAN_BP_IP; do 
		[ -n "$ip" ] && $NFT add element inet ss_spec bplan "{ $ip }" 2>/dev/null
    done
    for ip in $WAN_BP_IP; do 
		[ -n "$ip" ] && $NFT add element inet ss_spec whitelist "{ $ip }" 2>/dev/null
    done
    for ip in $WAN_FW_IP; do 
		[ -n "$ip" ] && $NFT add element inet ss_spec blacklist "{ $ip }" 2>/dev/null
    done

    # Create main chain for WAN access control
    if ! $NFT list chain inet ss_spec ss_spec_wan_ac >/dev/null 2>&1; then
		$NFT add chain inet ss_spec ss_spec_wan_ac 2>/dev/null
    fi
    $NFT flush chain inet ss_spec ss_spec_wan_ac 2>/dev/null

	# Create forward chain with better error handling
	if ! $NFT list chain inet ss_spec ss_spec_wan_fw >/dev/null 2>&1; then
		$NFT add chain inet ss_spec ss_spec_wan_fw 2>/dev/null || {
		loger 3 "Failed to create forward chain"
		return 1
		}
	fi
	# Clear existing rules
	$NFT flush chain inet ss_spec ss_spec_wan_fw 2>/dev/null
    
    # Add basic rules
    $NFT add rule inet ss_spec ss_spec_wan_ac tcp dport 53 ip daddr 127.0.0.0/8 return
    $NFT add rule inet ss_spec ss_spec_wan_ac tcp dport != 53 ip daddr "$server" return

    # Add special IP ranges to WAN AC set
    for ip in $(gen_spec_iplist); do
		[ -n "$ip" ] && $NFT add element inet ss_spec ss_spec_wan_ac "{ $ip }" 2>/dev/null
    done

    # Set up mode-specific rules
    case "$RUNMODE" in
    router)
		$NFT add rule inet ss_spec ss_spec_wan_ac ip daddr @ss_spec_wan_ac return
		$NFT add rule inet ss_spec ss_spec_wan_ac ip daddr @china return 2>/dev/null
		if $NFT list chain inet ss_spec ss_spec_wan_fw >/dev/null 2>&1; then
			$NFT add rule inet ss_spec ss_spec_wan_ac ip saddr @gmlan ip daddr != @china jump ss_spec_wan_fw
			$NFT add rule inet ss_spec ss_spec_wan_ac jump ss_spec_wan_fw
		fi
		;;
    gfw)
		if ! $NFT list set inet ss_spec gfwlist >/dev/null 2>&1; then
			$NFT add set inet ss_spec gfwlist '{ type ipv4_addr; flags interval; auto-merge; }' 2>/dev/null
		fi
		$NFT add rule inet ss_spec ss_spec_wan_ac ip daddr @china return 2>/dev/null
		$NFT add rule inet ss_spec ss_spec_wan_ac ip daddr @gfwlist jump ss_spec_wan_fw 2>/dev/null
		if $NFT list chain inet ss_spec ss_spec_wan_fw >/dev/null 2>&1; then
			$NFT add rule inet ss_spec ss_spec_wan_ac ip saddr @gmlan ip daddr != @china jump ss_spec_wan_fw
		fi
		;;
    oversea)
		if ! $NFT list set inet ss_spec oversea >/dev/null 2>&1; then
			$NFT add set inet ss_spec oversea '{ type ipv4_addr; flags interval; auto-merge; }' 2>/dev/null
		fi
		if $NFT list chain inet ss_spec ss_spec_wan_fw >/dev/null 2>&1; then
			$NFT insert rule inet ss_spec ss_spec_wan_ac ip daddr @oversea jump SS_SPEC_WAN_FW 2>/dev/null
			$NFT add rule inet ss_spec ss_spec_wan_ac ip saddr @gmlan jump ss_spec_wan_fw 2>/dev/null
			$NFT add rule inet ss_spec ss_spec_wan_ac ip daddr @china jump ss_spec_wan_fw 2>/dev/null
		fi
		;;
    all)
		if $NFT list chain inet ss_spec ss_spec_wan_fw >/dev/null 2>&1; then
			$NFT add rule inet ss_spec ss_spec_wan_ac jump ss_spec_wan_fw
		fi
		;;
    esac

    # Access control rules
    $NFT add rule inet ss_spec ss_spec_wan_ac ip saddr @fplan jump ss_spec_wan_fw
    $NFT add rule inet ss_spec ss_spec_wan_ac ip saddr @bplan return
    $NFT add rule inet ss_spec ss_spec_wan_ac ip daddr @blacklist jump ss_spec_wan_fw  
    $NFT add rule inet ss_spec ss_spec_wan_ac ip daddr @whitelist return

    # Music unlocking support
    if $NFT list set inet ss_spec music >/dev/null 2>&1; then
		$NFT insert rule inet ss_spec ss_spec_wan_ac ip daddr @music return 2>/dev/null
	fi

    # Shunt/Netflix rules
    if [ "$SHUNT_PORT" != "0" ] && [ -f "$SHUNT_LIST" ]; then
		for ip in $(cat "$SHUNT_LIST" 2>/dev/null); do 
			[ -n "$ip" ] && $NFT add element inet ss_spec netflix "{ $ip }" 2>/dev/null
		done
		PORTS=$(echo "$PROXY_PORTS" | sed 's/-m multiport --dports //')
		case "$SHUNT_PORT" in
		1)
			$NFT insert rule inet ss_spec ss_spec_wan_ac tcp dport { $PORTS } ip daddr @netflix redirect to :"$local_port"
        	;;
		*)
			$NFT insert rule inet ss_spec ss_spec_wan_ac tcp dport { $PORTS } ip daddr @netflix redirect to :"$SHUNT_PORT"
			if [ "$SHUNT_PROXY" = "1" ]; then
				$NFT insert rule inet ss_spec ss_spec_wan_ac tcp dport { $PORTS } ip daddr "$SHUNT_IP" redirect to :"$local_port"
			else
				[ -n "$SHUNT_IP" ] && $NFT add element inet ss_spec whitelist "{ $SHUNT_IP }" 2>/dev/null
			fi
			;;
		esac
    fi
    return $?
}

ipset_iptables() {
	[ -f "$IGNORE_LIST" ] && /usr/share/shadowsocksr/chinaipset.sh "$IGNORE_LIST"
	$IPT -N SS_SPEC_WAN_AC 2>/dev/null
	$IPT -I SS_SPEC_WAN_AC -p tcp --dport 53 -d 127.0.0.0/8 -j RETURN
	$IPT -I SS_SPEC_WAN_AC -p tcp ! --dport 53 -d "$server" -j RETURN
	ipset -N gmlan hash:net 2>/dev/null
	for ip in $LAN_GM_IP; do ipset -! add gmlan "$ip"; done
	case "$RUNMODE" in
	router)
		ipset -! -R <<-EOF || return 1
			create ss_spec_wan_ac hash:net
			$(gen_spec_iplist | sed -e "s/^/add ss_spec_wan_ac /")
		EOF
		$IPT -A SS_SPEC_WAN_AC -m set --match-set ss_spec_wan_ac dst -j RETURN
		$IPT -A SS_SPEC_WAN_AC -m set --match-set china dst -j RETURN
		$IPT -A SS_SPEC_WAN_AC -m set --match-set gmlan src -m set ! --match-set china dst -j SS_SPEC_WAN_FW
		$IPT -A SS_SPEC_WAN_AC -j SS_SPEC_WAN_FW
		;;
	gfw)
		ipset -N gfwlist hash:net 2>/dev/null
		$IPT -A SS_SPEC_WAN_AC -m set --match-set china dst -j RETURN
		$IPT -A SS_SPEC_WAN_AC -m set --match-set gfwlist dst -j SS_SPEC_WAN_FW
		$IPT -A SS_SPEC_WAN_AC -m set --match-set gmlan src -m set ! --match-set china dst -j SS_SPEC_WAN_FW
		;;
	oversea)
		ipset -N oversea hash:net 2>/dev/null
		$IPT -I SS_SPEC_WAN_AC -m set --match-set oversea dst -j SS_SPEC_WAN_FW
		$IPT -A SS_SPEC_WAN_AC -m set --match-set gmlan src -j SS_SPEC_WAN_FW
		$IPT -A SS_SPEC_WAN_AC -m set --match-set china dst -j SS_SPEC_WAN_FW
		;;
	all)
		$IPT -A SS_SPEC_WAN_AC -j SS_SPEC_WAN_FW
		;;
	esac
	ipset -N fplan hash:net 2>/dev/null
	for ip in $LAN_FP_IP; do ipset -! add fplan "$ip"; done
		$IPT -I SS_SPEC_WAN_AC -m set --match-set fplan src -j SS_SPEC_WAN_FW
	ipset -N bplan hash:net 2>/dev/null
	for ip in $LAN_BP_IP; do ipset -! add bplan "$ip"; done
		$IPT -I SS_SPEC_WAN_AC -m set --match-set bplan src -j RETURN
	ipset -N whitelist hash:net 2>/dev/null
	ipset -N blacklist hash:net 2>/dev/null
	$IPT -I SS_SPEC_WAN_AC -m set --match-set blacklist dst -j SS_SPEC_WAN_FW
	$IPT -I SS_SPEC_WAN_AC -m set --match-set whitelist dst -j RETURN
	if [ $(ipset list music -name -quiet | grep music) ]; then
		$IPT -I SS_SPEC_WAN_AC -m set --match-set music dst -j RETURN 2>/dev/null
	fi
	for ip in $WAN_BP_IP; do ipset -! add whitelist "$ip"; done
	for ip in $WAN_FW_IP; do ipset -! add blacklist "$ip"; done
	if [ "$SHUNT_PORT" != "0" ]; then
		ipset -N netflix hash:net 2>/dev/null
		for ip in $(cat "${SHUNT_LIST:=/dev/null}" 2>/dev/null); do ipset -! add netflix "$ip"; done
		case "$SHUNT_PORT" in
		0) ;;
		1)
			$IPT -I SS_SPEC_WAN_AC -p tcp -m set --match-set netflix dst -j REDIRECT --to-ports "$local_port"
			;;
		*)
			$IPT -I SS_SPEC_WAN_AC -p tcp -m set --match-set netflix dst -j REDIRECT --to-ports "$SHUNT_PORT"
			if [ "$SHUNT_PROXY" = "1" ]; then
				$IPT -I SS_SPEC_WAN_AC -p tcp -d "$SHUNT_IP" -j REDIRECT --to-ports "$local_port"
			else
				ipset -! add whitelist "$SHUNT_IP"
			fi
			;;
		esac
	fi
	return $?
}

fw_rule() {
	if [ "$USE_NFT" = "1" ]; then
		fw_rule_nft
	else
		fw_rule_iptables
	fi
	return $?
}

fw_rule_nft() {
	# Exclude special local addresses
	if $NFT list chain inet ss_spec ss_spec_wan_fw >/dev/null 2>&1; then
		for net in 0.0.0.0/8 10.0.0.0/8 127.0.0.0/8 169.254.0.0/16 172.16.0.0/12 192.168.0.0/16 224.0.0.0/4 240.0.0.0/4; do
			$NFT add rule inet ss_spec ss_spec_wan_fw ip daddr $net return 2>/dev/null
		done
	fi

	# redirect/translation: when PROXY_PORTS present, redirect those tcp ports to local_port
	if [ -n "$PROXY_PORTS" ]; then
		PORTS=$(echo "$PROXY_PORTS" | sed 's/-m multiport --dports //')
		RULE="tcp dport { $PORTS } redirect to :$local_port"
	else
		# default: redirect everything except ssh(22)
		RULE="tcp dport != 22 redirect to :$local_port"
	fi
	if ! $NFT list chain inet ss_spec ss_spec_wan_fw 2>/dev/null | grep -q "$RULE"; then
		if ! $NFT add rule inet ss_spec ss_spec_wan_fw $RULE 2>/dev/null; then
			loger 3 "Can't redirect, please check nftables."
			return 1
		fi
	fi

	return $?
}

fw_rule_iptables() {
	$IPT -N SS_SPEC_WAN_FW
	$IPT -A SS_SPEC_WAN_FW -d 0.0.0.0/8 -j RETURN
	$IPT -A SS_SPEC_WAN_FW -d 10.0.0.0/8 -j RETURN
	$IPT -A SS_SPEC_WAN_FW -d 127.0.0.0/8 -j RETURN
	$IPT -A SS_SPEC_WAN_FW -d 169.254.0.0/16 -j RETURN
	$IPT -A SS_SPEC_WAN_FW -d 172.16.0.0/12 -j RETURN
	$IPT -A SS_SPEC_WAN_FW -d 192.168.0.0/16 -j RETURN
	$IPT -A SS_SPEC_WAN_FW -d 224.0.0.0/4 -j RETURN
	$IPT -A SS_SPEC_WAN_FW -d 240.0.0.0/4 -j RETURN
	$IPT -A SS_SPEC_WAN_FW -p tcp $PROXY_PORTS -j REDIRECT --to-ports "$local_port" 2>/dev/null || {
		loger 3 "Can't redirect, please check the iptables."
		exit 1
	}
	return $?
}

ac_rule() {
	if [ "$USE_NFT" = "1" ]; then
		ac_rule_nft
	else
		ac_rule_iptables
	fi
	return $?
}

ac_rule_nft() {
	local MATCH_SET=""

	if [ -n "$LAN_AC_IP" ]; then
		# Create LAN access control set if needed
		if ! $NFT list set inet ss_spec ss_spec_lan_ac >/dev/null 2>&1; then
			$NFT add set inet ss_spec ss_spec_lan_ac '{ type ipv4_addr; flags interval; }' 2>/dev/null
		else
			$NFT flush set inet ss_spec ss_spec_lan_ac 2>/dev/null
		fi

		for ip in ${LAN_AC_IP#?}; do
			[ -n "$ip" ] && $NFT add element inet ss_spec ss_spec_lan_ac "{ $ip }" 2>/dev/null
		done

		case "${LAN_AC_IP%${LAN_AC_IP#?}}" in
		w | W)
			MATCH_SET="ip saddr @ss_spec_lan_ac"
			;;
		b | B)
			MATCH_SET="ip saddr != @ss_spec_lan_ac"
			;;
		*)
			loger 3 "Bad argument \`-a $LAN_AC_IP\`."
			return 2
			;;
		esac
	fi

	# 创建ss_spec_prerouting链
	if ! $NFT list chain inet ss_spec ss_spec_prerouting >/dev/null 2>&1; then
		$NFT add chain inet ss_spec ss_spec_prerouting '{ type nat hook prerouting priority -150; policy accept; }'
	fi
	$NFT flush chain inet ss_spec ss_spec_prerouting 2>/dev/null

	# 创建ss_spec_output链
	if ! $NFT list chain inet ss_spec ss_spec_output >/dev/null 2>&1; then
		$NFT add chain inet ss_spec ss_spec_output '{ type nat hook output priority -100; policy accept; }'
	fi
	$NFT flush chain inet ss_spec ss_spec_output 2>/dev/null

	# Build a rule in the prerouting hook chain that jumps to business chain with conditions
	if [ -n "$PROXY_PORTS" ]; then
		EXT_ARGS=$(echo "$PROXY_PORTS" | sed 's/-m multiport --dports //')
	fi

	if [ -z "$Interface" ]; then
		# generic prerouting jump already exists (see ipset_nft), but if we have MATCH_SET_CONDITION we add a more specific rule
		if [ -n "$MATCH_SET" ]; then
			# add a more specific rule at the top of ss_spec_prerouting
			$NFT insert rule inet ss_spec ss_spec_prerouting meta l4proto tcp th dport { $EXT_ARGS } $MATCH_SET jump ss_spec_wan_ac comment "\"$TAG\"" 2>/dev/null
		else
			$NFT insert rule inet ss_spec ss_spec_prerouting meta l4proto tcp th dport { $EXT_ARGS } jump ss_spec_wan_ac comment "\"$TAG\"" 2>/dev/null
		fi
	else
		# For each Interface, find its actual ifname and add an iifname-limited prerouting rule
		for name in $Interface; do
			local IFNAME=$(uci -P /var/state get network."$name".ifname 2>/dev/null)
			[ -z "$IFNAME" ] && IFNAME=$(uci -P /var/state get network."$name".device 2>/dev/null)
			if [ -n "$IFNAME" ]; then
				if [ -n "$MATCH_SET" ]; then
					$NFT insert rule inet ss_spec ss_spec_prerouting meta iifname "$IFNAME" meta l4proto tcp th dport { $EXT_ARGS } $MATCH_SET jump ss_spec_wan_ac comment "\"$TAG\"" 2>/dev/null
				else
					$NFT insert rule inet ss_spec ss_spec_prerouting meta iifname "$IFNAME" meta l4proto tcp th dport { $EXT_ARGS } jump ss_spec_wan_ac comment "\"$TAG\"" 2>/dev/null
				fi
			fi
		done
	fi

	case "$OUTPUT" in
	1)
		# create output hook chain & route output traffic into router chain
		$NFT insert rule inet ss_spec ss_spec_output meta l4proto tcp th dport { $EXT_ARGS } jump ss_spec_wan_ac comment "\"$TAG\"" 2>/dev/null
		;;
	2)
		# router mode output chain: create ssr_gen_router set & router chain
		$NFT add set inet ss_spec ssr_gen_router '{ type ipv4_addr; flags interval; }' 2>/dev/null
		for ip in $(gen_spec_iplist); do
			[ -n "$ip" ] && $NFT add element inet ss_spec ssr_gen_router "{ $ip }" 2>/dev/null
		done
		$NFT add chain inet ss_spec ss_spec_router 2>/dev/null
		$NFT add rule inet ss_spec ss_spec_router ip daddr @ssr_gen_router return 2>/dev/null
		$NFT add rule inet ss_spec ss_spec_router jump ss_spec_wan_fw 2>/dev/null
		$NFT add rule inet ss_spec ss_spec_output meta l4proto tcp th dport { $EXT_ARGS } jump ss_spec_router comment "\"$TAG\"" 2>/dev/null
		;;
	esac
	return 0
}

ac_rule_iptables() {
	if [ -n "$LAN_AC_IP" ]; then
		case "${LAN_AC_IP%${LAN_AC_IP#?}}" in
		w | W)
			MATCH_SET="-m set --match-set ss_spec_lan_ac src"
			;;
		b | B)
			MATCH_SET="-m set ! --match-set ss_spec_lan_ac src"
			;;
		*)
			loger 3 "Bad argument \`-a $LAN_AC_IP\`."
			return 2
			;;
		esac
	fi
	ipset -! -R <<-EOF || return 1
		create ss_spec_lan_ac hash:net
		$(for ip in ${LAN_AC_IP#?}; do echo "add ss_spec_lan_ac $ip"; done)
	EOF
	if [ -z "$Interface" ]; then
		$IPT -I PREROUTING 1 -p tcp $EXT_ARGS $MATCH_SET -m comment --comment "$TAG" -j SS_SPEC_WAN_AC
	else
		for name in $Interface; do
			local IFNAME=$(uci -P /var/state get network."$name".ifname 2>/dev/null)
			[ -z "$IFNAME" ] && IFNAME=$(uci -P /var/state get network."$name".device 2>/dev/null)
			[ -n "$IFNAME" ] && $IPT -I PREROUTING 1 ${IFNAME:+-i $IFNAME} -p tcp $EXT_ARGS $MATCH_SET -m comment --comment "$TAG" -j SS_SPEC_WAN_AC
		done
	fi

	case "$OUTPUT" in
	1)
		$IPT -I OUTPUT 1 -p tcp $EXT_ARGS -m comment --comment "$TAG" -j SS_SPEC_WAN_AC
		;;
	2)
		ipset -! -R <<-EOF || return 1
			create ssr_gen_router hash:net
			$(gen_spec_iplist | sed -e "s/^/add ssr_gen_router /")
		EOF
		$IPT -N SS_SPEC_ROUTER && \
		$IPT -A SS_SPEC_ROUTER -m set --match-set ssr_gen_router dst -j RETURN && \
		$IPT -A SS_SPEC_ROUTER -j SS_SPEC_WAN_FW
		$IPT -I OUTPUT 1 -p tcp -m comment --comment "$TAG" -j SS_SPEC_ROUTER
		;;
	esac
	return $?
}

tp_rule() {
	[ -n "$TPROXY" ] || return 0
	if [ "$USE_NFT" = "1" ]; then
		tp_rule_nft
	else
		tp_rule_iptables
	fi
	return $?
}

tp_rule_nft() {
	# set up routing table for tproxy
	ip rule add fwmark 0x01/0x01 table 100 2>/dev/null
	ip route add local 0.0.0.0/0 dev lo table 100 2>/dev/null

	# create mangle table and tproxy chain
	if ! $NFT list table ip ss_spec_mangle >/dev/null 2>&1; then
		$NFT add table ip ss_spec_mangle 2>/dev/null
	fi

	local MATCH_SET=""
	local EXT_ARGS=""

	if [ -n "$PROXY_PORTS" ]; then
		EXT_ARGS=$(echo "$PROXY_PORTS" | sed 's/-m multiport --dports //')
	fi

	if [ -n "$LAN_AC_IP" ]; then
		# Create LAN access control set if needed
		if ! $NFT list set ip ss_spec_mangle ss_spec_lan_ac >/dev/null 2>&1; then
			$NFT add set ip ss_spec_mangle ss_spec_lan_ac '{ type ipv4_addr; flags interval; auto-merge; }' 2>/dev/null
		else
			$NFT flush set ip ss_spec_mangle ss_spec_lan_ac 2>/dev/null
		fi

		for ip in ${LAN_AC_IP#?}; do
			[ -n "$ip" ] && $NFT add element ip ss_spec_mangle ss_spec_lan_ac "{ $ip }" 2>/dev/null
		done

		case "${LAN_AC_IP%${LAN_AC_IP#?}}" in
		w | W)
			MATCH_SET="ip saddr @ss_spec_lan_ac"
			;;
		b | B)
			MATCH_SET="ip saddr != @ss_spec_lan_ac"
			;;
		*)
			loger 3 "Bad argument \`-a $LAN_AC_IP\`."
			return 2
			;;
		esac
	fi

	# Create necessary collections
	for setname in ss_spec_wan_ac china gmlan fplan bplan whitelist; do
		if ! $NFT list set ip ss_spec_mangle $setname >/dev/null 2>&1; then
			$NFT add set ip ss_spec_mangle $setname '{ type ipv4_addr; flags interval; auto-merge; }'
		else
			$NFT flush set ip ss_spec_mangle $setname 2>/dev/null
		fi
	done

	# 批量导入中国IP列表
	if [ -f "${china_ip:=/etc/ssrplus/china_ssr.txt}" ]; then
		$NFT add element ip ss_spec_mangle china { $(tr '\n' ',' < "${china_ip}" | sed 's/,$//') } 2>/dev/null
	fi

	# use priority mangle for compatibility with other rules
	if ! $NFT list chain ip ss_spec_mangle ss_spec_tproxy >/dev/null 2>&1; then
		$NFT add chain ip ss_spec_mangle ss_spec_tproxy 2>/dev/null
	else
		$NFT flush chain ip ss_spec_mangle ss_spec_tproxy 2>/dev/null
	fi

	# basic return rules in tproxy chain
	$NFT add rule ip ss_spec_mangle ss_spec_tproxy udp dport 53 return 2>/dev/null

	if $NFT list chain ip ss_spec_mangle ss_spec_tproxy >/dev/null 2>&1; then
		for net in 0.0.0.0/8 10.0.0.0/8 127.0.0.0/8 169.254.0.0/16 172.16.0.0/12 192.168.0.0/16 224.0.0.0/4 240.0.0.0/4; do
			$NFT add rule ip ss_spec_mangle ss_spec_tproxy ip daddr $net return 2>/dev/null
		done
	fi

	# avoid redirecting to udp server address
	if [ -n "$server" ]; then
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy udp dport != 53 ip daddr "$server" return 2>/dev/null
	fi

	# if server != SERVER add SERVER to whitelist set (so tproxy won't touch it)
	if [ -n "$server" ]; then
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy ip daddr "$server" return 2>/dev/null
	fi
	if [ -n "$SERVER" ] && [ "$server" != "$SERVER" ]; then
		$NFT add element ip ss_spec_mangle whitelist "{ $SERVER }" 2>/dev/null
	fi

	# access control and tproxy rules
	$NFT add rule ip ss_spec_mangle ss_spec_tproxy meta l4proto udp ip saddr @bplan return 2>/dev/null

	if [ -n "$EXT_ARGS" ]; then
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy udp dport { $EXT_ARGS } ip saddr @fplan tproxy to :"$LOCAL_PORT" meta mark set 0x01
	else
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy meta l4proto udp ip saddr @fplan tproxy to :"$LOCAL_PORT" meta mark set 0x01 2>/dev/null
	fi

	# Handle different run modes for nftables
	case "$RUNMODE" in
	router)
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy meta l4proto udp ip daddr @ss_spec_wan_ac return 2>/dev/null
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy meta l4proto udp ip daddr @china return 2>/dev/null
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy udp dport 80 drop 2>/dev/null
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy meta l4proto udp ip saddr @gmlan ip daddr != @china tproxy to :"$LOCAL_PORT" meta mark set 0x01 2>/dev/null
		if [ -n "$EXT_ARGS" ]; then
			$NFT add rule ip ss_spec_mangle ss_spec_tproxy udp dport { $EXT_ARGS } ip daddr != @ss_spec_wan_ac tproxy to :"$LOCAL_PORT" meta mark set 0x01 2>/dev/null
		else
			$NFT add rule ip ss_spec_mangle ss_spec_tproxy meta l4proto udp ip daddr != @ss_spec_wan_ac tproxy to :"$LOCAL_PORT" meta mark set 0x01 2>/dev/null
		fi
		;;
	gfw)
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy meta l4proto udp ip daddr @china return 2>/dev/null
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy udp dport 80 drop 2>/dev/null
		if [ -n "$EXT_ARGS" ]; then
			$NFT add rule ip ss_spec_mangle ss_spec_tproxy udp dport { $EXT_ARGS } ip daddr @gfwlist tproxy to :"$LOCAL_PORT" meta mark set 0x01 2>/dev/null
		fi
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy meta l4proto udp ip saddr @gmlan ip daddr != @china tproxy to :"$LOCAL_PORT" meta mark set 0x01 2>/dev/null
		;;
	oversea)
		if ! $NFT list set ip ss_spec_mangle oversea >/dev/null 2>&1; then
			$NFT add set ip ss_spec_mangle oversea '{ type ipv4_addr; flags interval; auto-merge; }' 2>/dev/null
		fi
		if ! $NFT list set ip ss_spec_mangle china >/dev/null 2>&1; then
			$NFT add set ip ss_spec_mangle china '{ type ipv4_addr; flags interval; auto-merge; }' 2>/dev/null
		fi
		if [ -n "$EXT_ARGS" ]; then
			$NFT add rule ip ss_spec_mangle ss_spec_tproxy udp dport { $EXT_ARGS } ip saddr @oversea tproxy to :"$LOCAL_PORT" meta mark set 0x01 2>/dev/null
			$NFT add rule ip ss_spec_mangle ss_spec_tproxy udp dport { $EXT_ARGS } ip daddr @china tproxy to :"$LOCAL_PORT" meta mark set 0x01 2>/dev/null
		fi
		$NFT add rule ip ss_spec_mangle ss_spec_tproxy meta l4proto udp ip saddr @gmlan tproxy to :"$LOCAL_PORT" meta mark set 0x01 2>/dev/null
		;;
	all)
		if [ -n "$EXT_ARGS" ]; then
			$NFT add rule ip ss_spec_mangle ss_spec_tproxy udp dport { $EXT_ARGS } tproxy to :"$LOCAL_PORT" meta mark set 0x01 2>/dev/null
		else
			$NFT add rule ip ss_spec_mangle ss_spec_tproxy udp tproxy to :"$LOCAL_PORT" meta mark set 0x01 2>/dev/null
		fi
		;;
	esac

	# 创建 prerouting 链（hook prerouting）
	if ! $NFT list chain ip ss_spec_mangle prerouting >/dev/null 2>&1; then
		$NFT add chain ip ss_spec_mangle prerouting '{ type filter hook prerouting priority mangle; policy accept; }'
	fi

	# 添加规则到 prerouting 链
	if [ -z "$Interface" ]; then
		# 全局规则
		if [ -n "$MATCH_SET" ]; then
			$NFT add rule ip ss_spec_mangle prerouting udp dport { $EXT_ARGS } $MATCH_SET jump ss_spec_tproxy comment "\"$TAG\"" 2>/dev/null
		else
			$NFT add rule ip ss_spec_mangle prerouting udp dport { $EXT_ARGS } jump ss_spec_tproxy comment "\"$TAG\"" 2>/dev/null
		fi
	else
		# 指定接口
		for name in $Interface; do
			IFNAME=$(uci -P /var/state get network."$name".ifname 2>/dev/null)
			[ -z "$IFNAME" ] && IFNAME=$(uci -P /var/state get network."$name".device 2>/dev/null)
			if [ -n "$IFNAME" ]; then
				if [ -n "$MATCH_SET" ]; then
					$NFT add rule ip ss_spec_mangle prerouting meta iifname "$IFNAME" udp dport { $EXT_ARGS } $MATCH_SET jump ss_spec_tproxy comment "\"$TAG\"" 2>/dev/null
				else
					$NFT add rule ip ss_spec_mangle prerouting meta iifname "$IFNAME" udp dport { $EXT_ARGS } jump ss_spec_tproxy comment "\"$TAG\"" 2>/dev/null
				fi
			fi
		done
	fi

	return $?
}

tp_rule_iptables() {
	ip rule add fwmark 0x01/0x01 table 100
	ip route add local 0.0.0.0/0 dev lo table 100
	local ipt="iptables -t mangle"
	$ipt -N SS_SPEC_TPROXY
	$ipt -A SS_SPEC_TPROXY -p udp --dport 53 -j RETURN
	$ipt -A SS_SPEC_TPROXY -p udp -d 0.0.0.0/8 -j RETURN
	$ipt -A SS_SPEC_TPROXY -p udp -d 10.0.0.0/8 -j RETURN
	$ipt -A SS_SPEC_TPROXY -p udp -d 127.0.0.0/8 -j RETURN
	$ipt -A SS_SPEC_TPROXY -p udp -d 169.254.0.0/16 -j RETURN
	$ipt -A SS_SPEC_TPROXY -p udp -d 172.16.0.0/12 -j RETURN
	$ipt -A SS_SPEC_TPROXY -p udp -d 192.168.0.0/16 -j RETURN
	$ipt -A SS_SPEC_TPROXY -p udp -d 224.0.0.0/4 -j RETURN
	$ipt -A SS_SPEC_TPROXY -p udp -d 240.0.0.0/4 -j RETURN
	$ipt -A SS_SPEC_TPROXY -p udp ! --dport 53 -d "$SERVER" -j RETURN
	[ "$server" != "$SERVER" ] && ipset -! add whitelist "$SERVER"
	$ipt -A SS_SPEC_TPROXY -p udp -m set --match-set bplan src -j RETURN
	$ipt -A SS_SPEC_TPROXY -p udp $PROXY_PORTS -m set --match-set fplan src -j TPROXY --on-port "$LOCAL_PORT" --tproxy-mark 0x01/0x01
	case "$RUNMODE" in
	router)
		$ipt -A SS_SPEC_TPROXY -p udp -m set --match-set ss_spec_wan_ac dst -j RETURN
		$ipt -A SS_SPEC_TPROXY -p udp -m set --match-set china dst -j RETURN
		$ipt -A SS_SPEC_TPROXY -p udp --dport 80 -j DROP
		$ipt -A SS_SPEC_TPROXY -p udp -m set --match-set gmlan src -m set ! --match-set china dst -j TPROXY --on-port "$LOCAL_PORT" --tproxy-mark 0x01/0x01
		$ipt -A SS_SPEC_TPROXY -p udp $PROXY_PORTS -m set ! --match-set ss_spec_wan_ac dst -j TPROXY --on-port "$LOCAL_PORT" --tproxy-mark 0x01/0x01
		;;
	gfw)
		$ipt -A SS_SPEC_TPROXY -p udp -m set --match-set china dst -j RETURN
		$ipt -A SS_SPEC_TPROXY -p udp --dport 80 -j DROP
		$ipt -A SS_SPEC_TPROXY -p udp $PROXY_PORTS -m set --match-set gfwlist dst -j TPROXY --on-port "$LOCAL_PORT" --tproxy-mark 0x01/0x01
		$ipt -A SS_SPEC_TPROXY -p udp -m set --match-set gmlan src -m set ! --match-set china dst -j TPROXY --on-port "$LOCAL_PORT" --tproxy-mark 0x01/0x01
		;;
	oversea)
		$ipt -A SS_SPEC_TPROXY -p udp $PROXY_PORTS -m set --match-set oversea src -m dst -j TPROXY --on-port "$LOCAL_PORT" --tproxy-mark 0x01/0x01
		$ipt -A SS_SPEC_TPROXY -p udp -m set --match-set gmlan src -m set -j TPROXY --on-port "$LOCAL_PORT" --tproxy-mark 0x01/0x01
		$ipt -A SS_SPEC_TPROXY -p udp $PROXY_PORTS -m set --match-set china dst -j TPROXY --on-port "$LOCAL_PORT" --tproxy-mark 0x01/0x01
		;;
	all)
		$ipt -A SS_SPEC_TPROXY -p udp $PROXY_PORTS -j TPROXY --on-port "$LOCAL_PORT" --tproxy-mark 0x01/0x01
		;;
	esac
	if [ -z "$Interface" ]; then
		$ipt -I PREROUTING 1 -p udp $EXT_ARGS $MATCH_SET -m comment --comment "$TAG" -j SS_SPEC_TPROXY
	else
		for name in $Interface; do
			local IFNAME=$(uci -P /var/state get network."$name".ifname 2>/dev/null)
			[ -z "$IFNAME" ] && IFNAME=$(uci -P /var/state get network."$name".device 2>/dev/null)
			[ -n "$IFNAME" ] && $ipt -I PREROUTING 1 ${IFNAME:+-i $IFNAME} -p udp $EXT_ARGS $MATCH_SET -m comment --comment "$TAG" -j SS_SPEC_TPROXY
		done
	fi
	return $?
}

get_wan_ip() {
	cat <<-EOF | grep -E "^([0-9]{1,3}\.){3}[0-9]{1,3}"
		$server
		$SERVER
		$WAN_BP_IP
	EOF
}

gen_spec_iplist() {
	cat <<-EOF
		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
		192.88.99.0/24
		192.168.0.0/16
		198.18.0.0/15
		198.51.100.0/24
		203.0.113.0/24
		224.0.0.0/4
		240.0.0.0/4
		255.255.255.255
		$(get_wan_ip)
	EOF
}

gen_include() {
	[ -n "$FWI" ] || return 0
	if [ "$USE_NFT" = "1" ]; then
		gen_include_nft
	else
		gen_include_iptables
	fi
	return $?
}

gen_include_nft() {
	# Generate nftables include file for firewall4
	[ -n "$FWI" ] && echo '#!/bin/sh' >"$FWI"
	cat <<-'EOF' >>"$FWI"
		# Clear existing ss_spec tables
		nft delete table inet ss_spec 2>/dev/null
		nft delete table ip ss_spec 2>/dev/null
		nft delete table ip ss_spec_mangle 2>/dev/null

		# Restore shadowsocks nftables rules
		nft list ruleset | awk '/^table (inet|ip) ss_spec/{flag=1} /^table / && !/^table (inet|ip) ss_spec/{flag=0} flag'
	EOF
	chmod +x "$FWI"
}

gen_include_iptables() {
	extract_rules() {
		echo "*$1"
		iptables-save -t $1 | grep SS_SPEC_ | sed -e "s/^-A \(OUTPUT\|PREROUTING\)/-I \1 1/"
		echo 'COMMIT'
	}
	cat <<-EOF >>$FWI
		iptables-save -c | grep -v "SS_SPEC" | iptables-restore -c
		iptables-restore -n <<-EOT
		$(extract_rules nat)
		$(extract_rules mangle)
		EOT
	EOF
}

while getopts ":m:s:l:S:L:i:e:a:B:b:w:p:G:D:F:N:M:I:oOuUfgrczh" arg; do
	case "$arg" in
	m)
		Interface=$OPTARG
		;;
	s)
		server=$OPTARG
		;;
	l)
		local_port=$OPTARG
		;;
	S)
		SERVER=$OPTARG
		;;
	L)
		LOCAL_PORT=$OPTARG
		;;
	i)
		IGNORE_LIST=$OPTARG
		;;
	e)
		EXT_ARGS=$OPTARG
		;;
	a)
		LAN_AC_IP=$OPTARG
		;;
	B)
		LAN_BP_IP=$OPTARG
		;;
	b)
		WAN_BP_IP=$(for ip in $OPTARG; do echo "$ip"; done)
		;;
	w)
		WAN_FW_IP=$OPTARG
		;;
	p)
		LAN_FP_IP=$OPTARG
		;;
	G)
		LAN_GM_IP=$OPTARG
		;;
	D)
		PROXY_PORTS=$OPTARG
		;;
	F)
		SHUNT_PORT=$OPTARG
		;;
	N)
		SHUNT_IP=$OPTARG
		;;
	M)
		SHUNT_PROXY=$OPTARG
		;;
	I)
		SHUNT_LIST=$OPTARG
		;;
	o)
		OUTPUT=1
		;;
	O)
		OUTPUT=2
		;;
	u)
		TPROXY=1
		;;
	U)
		TPROXY=2
		;;
	g)
		RUNMODE=gfw
		;;
	r)
		RUNMODE=router
		;;
	c)
		RUNMODE=oversea
		;;
	z)
		RUNMODE=all
		;;
	f)
		flush_r
		exit 0
		;;
	h) usage 0 ;;
	esac
done

if [ -z "$server" ] || [ -z "$local_port" ]; then
	usage 2
fi

if ! echo "$local_port" | grep -qE '^[0-9]+$'; then
	loger 3 "Invalid local port: $local_port"
	exit 1
fi

case "$TPROXY" in
1)
	SERVER=$server
	LOCAL_PORT=$local_port
	;;
2)
	: ${SERVER:?"You must assign an ip for the udp relay server."}
	: ${LOCAL_PORT:?"You must assign a port for the udp relay server."}
	;;
esac

# First check whether nftables is working properly
if [ "$USE_NFT" = "1" ]; then
	if ! $NFT list tables 2>/dev/null; then
		loger 3 "nftables is not working properly, check if nftables is installed and running"
		exit 1
	fi
fi

if [ "$USE_NFT" = "1" ]; then
	# NFTables
	if flush_r && ipset_r && fw_rule && ac_rule && tp_rule && gen_include; then
		loger 5 "NFTables rules applied successfully"
		exit 0
	else
		loger 3 "NFTables setup failed!"
		exit 1
	fi
else
	# iptables
	if flush_r && fw_rule && ipset_r && ac_rule && tp_rule && gen_include; then
		loger 5 "iptables rules applied successfully"
		exit 0
	else
		loger 3 "iptables setup failed!"
		exit 1
	fi
fi