openvpn-updown.sh

#!/bin/sh
# date: 2019-08-02
# license: GPLv3 https://www.gnu.org/licenses/gpl-3.0.txt
# author: nanpuyue <nanpuyue@gmail.com> https://blog.nanpuyue.com

MARK=404
TABLE=404
SETNAME="surfing telegram"
VERBOSE=0

iptables(){
    case $* in
        *-A*|*-I*)
            if command iptables $(echo $@|sed -r 's/(-A)|(-I)/-C/') 2>/dev/null; then
                return 0
            else
                [ "$VERBOSE" = 1 ] && echo iptables "$@"
                command iptables $@
            fi
        ;;
        *-D*)
            if command iptables $(echo $@|sed -r 's/-D/-C/') 2>/dev/null; then
                [ "$VERBOSE" = 1 ] && echo iptables "$@"
                command iptables $@
            else
                return 0
            fi
       ;;
       *)
           [ "$VERBOSE" = 1 ] && echo iptables "$@"
           command iptables $@
       ;;
    esac
}

up() {
    for setname in $SETNAME; do
        for chain in PREROUTING OUTPUT; do
            iptables -t mangle -I $chain -m set --match-set $setname dst -j MARK --set-mark $MARK
        done
    done

    ip route add default via $route_vpn_gateway dev $dev table $TABLE
    ip rule add fwmark $MARK table $TABLE
} 

down() {
    for setname in $SETNAME; do
        for chain in PREROUTING OUTPUT; do
            iptables -t mangle -D $chain -m set --match-set $setname dst -j MARK --set-mark $MARK
        done
    done

    ip route del default via $route_vpn_gateway dev $dev table $TABLE
    ip rule del fwmark $MARK table $TABLE
}

case $script_type in
    up)
        up
    ;;
    down)
        down
    ;;
esac