#!/bin/sh /etc/rc.common
PKG_VERSION=

START=94
USE_PROCD=1

readonly TID="200" FW_MARK="0x010000" IPSET="vpnbypass"

output() {
	[ -n "$2" ] && [ ! $(($verbosity & $2)) -gt 0 ] && return 0;
	[ -t 1 ] && echo -e -n "$1"
	[ $(echo -e -n "$1" | wc -l) -gt 0 ] && logger -t "${PKG_NAME:-service} [$$]" "$(echo -e -n ${logmsg}${1})" && logmsg='' || logmsg=${logmsg}${1}
}

vpnbypass_enabled() {
	config_load vpnbypass
	config_get_bool enabled 'config' 'enabled' 0
	config_get verbosity    'config' 'verbosity' '2'
	PKG_NAME="${PKG_NAME:-vpnbypass}"
	[ -n "$PKG_VERSION" ] && p_name="$PKG_NAME $PKG_VERSION" || p_name="$PKG_NAME"
	[ -t 1 ] || p_name='service'
	source /lib/functions/network.sh
	[ "$enabled" -ne "0" ] && return 0
	output "$p_name is not enabled in the config file!\n"
	output "To enable, run 'uci set $PKG_NAME.config.enabled=1; uci commit $PKG_NAME'\n"
	return 1
}

iptables_reset(){ [ -z "$PKG_NAME" ] && return 1; iptables-save | grep -Fv -- "$PKG_NAME" | iptables-restore; lsmod | grep -q ip6table_nat && ip6tables-save | grep -Fv -- "$PKG_NAME" | ip6tables-restore; }

boot() { ubus -t 30 wait_for network.interface.wan && { rc_procd start_service; rc_procd service_triggers; } || output "ERROR: $p_name failed to settle network interface!\n"; }

start_service() {
	local ll c=1
  config_load vpnbypass
  vpnbypass_enabled || return 1
  config_get lports   'config' 'localport'
  config_get rports   'config' 'remoteport'
  config_get routes   'config' 'remotesubnet'
  config_get ranges   'config' 'localsubnet'
  config_get domains  'config' 'domain'

	procd_open_instance
	procd_set_param stdout 1
	procd_set_param stderr 1
	procd_close_instance

	while : ; do network_get_ipaddr wanip wan; network_get_gateway gwip wan; [ $c -ge 15 ] && break || let "c+=1"; [ -n "$wanip" -a -n "$gwip" ] && break || output "$p_name waiting for wan gateway...\n"; sleep 2; network_flush_cache; done
	[ -z "$wanip" -o -z "$gwip" ] && output "ERROR: $p_name could not get wan interface IP: $wanip or gateway: $gwip!\n" && exit 0

	for ll in ${routes}; do ip route del $ll; ip route add $ll via $gwip; done
	ip rule del fwmark "$FW_MARK" table "$TID" >/dev/null 2>&1; iptables_reset; ipset -q flush "$IPSET"; ipset -q destroy "$IPSET";
	ip route flush table "$TID"; ip route flush cache;
	ip route add default via "$gwip" table "$TID"; ip route flush cache;
	{ modprobe xt_set; modprobe ip_set; modprobe ip_set_hash_ip; } >/dev/null 2>&1
	ipset -q -exist create "$IPSET" hash:ip; ipset -q flush "$IPSET"
	for ll in ${lports}; do iptables -t mangle -A PREROUTING -p tcp -m multiport --sport "${ll//-/:}" -j MARK --set-mark "$FW_MARK/$FW_MARK" -m comment --comment "$PKG_NAME"; done
	for ll in ${rports}; do iptables -t mangle -A PREROUTING -p tcp -m multiport --dport "${ll//-/:}" -j MARK --set-mark "$FW_MARK/$FW_MARK" -m comment --comment "$PKG_NAME"; done
	for ll in ${ranges}; do iptables -t mangle -I PREROUTING -s "$ll" -j MARK --set-mark "$FW_MARK/$FW_MARK" -m comment --comment "$PKG_NAME"; done
	iptables -t mangle -A PREROUTING -m set --match-set "$IPSET" dst -j MARK --set-mark "$FW_MARK/$FW_MARK" -m comment --comment "$PKG_NAME"
	ip rule add fwmark "$FW_MARK" table "$TID"
	output "$p_name started with TID: $TID; FW_MARK: $FW_MARK\n"
}

stop_service() {
	local ll
  vpnbypass_enabled || return 1
  config_get routes   'config' 'remotesubnet'

	for ll in ${routes}; do ip route del "$ll"; done
	ip rule del fwmark "$FW_MARK" table "$TID" >/dev/null 2>&1; iptables_reset; ipset -q flush "$IPSET"; ipset -q destroy "$IPSET";
	ip route flush table "$TID"; ip route flush cache;
	output "$p_name stopped\n"
}

reload_service() { start_service; }

service_triggers() {
		procd_add_reload_trigger 'vpnbypass'
		procd_open_trigger
		procd_add_config_trigger "config.change" "vpnbypass" /etc/init.d/vpnbypass reload
		procd_add_interface_trigger "interface.*" "wan" /etc/init.d/vpnbypass reload
		procd_close_trigger
}