gw=$(ip route | sed -rn 's/^default via .* dev (\S+).*/\1/p' | head -n1)
-cat >/etc/systemd/system/vpnnat.service <<EOF
-[Unit]
-Description=Turns on nat iptables setting
-
-[Install]
-WantedBy=$vpn_service.service
-
+d=/etc/systemd/system/$vpn_service.service.d
+mkdir -p $d
+f=$d/nat.conf
+cat >$f <<EOF
[Service]
-Type=oneshot
-RemainAfterExit=yes
-ExecStart=/sbin/iptables -t nat -A POSTROUTING -s $ip4.0/24 -o $gw -j MASQUERADE
-ExecStop=/sbin/iptables -t nat -D POSTROUTING -s $ip4.0/24 -o $gw -j MASQUERADE
+ExecStartPre=/sbin/iptables -t nat -A POSTROUTING -s $ip4.0/24 -o $gw -j MASQUERADE
+ExecStopPost=/sbin/iptables -t nat -D POSTROUTING -s $ip4.0/24 -o $gw -j MASQUERADE
EOF
-
-
if [[ $ip6net ]]; then
- cat >>/etc/systemd/system/vpnnat.service <<EOF
-ExecStart=/sbin/ip6tables -t nat -A POSTROUTING -s $ip6net -o $gw -j MASQUERADE
-ExecStop=/sbin/ip6tables -t nat -D POSTROUTING -s $ip6net -o $gw -j MASQUERADE
+ cat >>$f <<EOF
+ExecStartPre=/sbin/ip6tables -t nat -A POSTROUTING -s $ip6net -o $gw -j MASQUERADE
+ExecStopPost=/sbin/ip6tables -t nat -D POSTROUTING -s $ip6net -o $gw -j MASQUERADE
EOF
-systemctl daemon-reload # needed if the file was already there
-# note, no need to start it, the vpn_service does that.
-systemctl enable vpnnat
+ systemctl daemon-reload # needed if the file was already there
-if $start; then
- systemctl enable $vpn_service
- systemctl restart $vpn_service
+ if $start; then
+ systemctl enable $vpn_service
+ systemctl restart $vpn_service
+ fi
fi