#!/usr/bin/env bash
#
# Parses DHCP options from openvpn to update resolv.conf
# To use set as 'up' and 'down' script in your openvpn *.conf:
# up /etc/openvpn/update-resolv-conf
# down /etc/openvpn/update-resolv-conf
#
# Example envs set from openvpn:
# foreign_option_1='dhcp-option DNS 193.43.27.132'
# foreign_option_2='dhcp-option DNS 193.43.27.133'
# foreign_option_3='dhcp-option DOMAIN be.bnc.ch'
# foreign_option_4='dhcp-option DOMAIN-SEARCH bnc.local'

case $script_type in

up)
    for optionname in ${!foreign_option_*} ; do
        option="${!optionname}"
        echo $option
        part1=$(echo "$option" | cut -d " " -f 1)
        if [ "$part1" == "dhcp-option" ] ; then
            part2=$(echo "$option" | cut -d " " -f 2)
            part3=$(echo "$option" | cut -d " " -f 3)
            if [ "$part2" == "DNS" ] ; then
                IF_DNS_NAMESERVERS="$IF_DNS_NAMESERVERS $part3"
            fi
            if [[ "$part2" == "DOMAIN" || "$part2" == "DOMAIN-SEARCH" ]] ; then
                IF_DNS_SEARCH="$IF_DNS_SEARCH $part3"
            fi
        fi
    done
    if [ -n "$IF_DNS_SEARCH" ]; then
        nmcli connection modify "${dev}" ipv4.dns-search "$IF_DNS_SEARCH"
    fi
    if [ -n "$IF_DNS_NAMESERVERS" ]; then
        nmcli connection modify "${dev}" ipv4.dns "$IF_DNS_NAMESERVERS"
    fi
    nmcli connection up "${dev}" # Force NM to reevaluate the properties
    ;;
esac

# Workaround / jm@epiclabs.io
# force exit with no errors. Due to an apparent conflict with the Network Manager
# $RESOLVCONF sometimes exits with error code 6 even though it has performed the
# action correctly and OpenVPN shuts down.
exit 0