vpnclient_ynh/conf/scripts/route-down.d/40-vpnclient-unset-ipv6

#!/bin/bash

is_ip6addr_set() {
  local ip6_addr=${1}
  ip address show dev "${gateway_interface}" 2> /dev/null | grep -q "${ip6_addr}/"
}

ip6_addr=$(yunohost app setting "vpnclient" "ip6_addr")
# cf https://openvpn.net/community-resources/reference-manual-for-openvpn-2-4/#environmental-variables for where 'dev' comes from
gateway_interface=${dev}

if [[ -n "${ip6_addr}" ]] && [[ "${ip6_addr}" != none ]] && is_ip6addr_set "${ip6_addr}"; then
  ip address delete "${ip6_addr}/64" dev "${gateway_interface}"
fi