#!/bin/sh
iface=$1

lock=/var/run/dhclient.$iface.lock
lockfile-create --use-pid $lock

run_dhclient() {
  local suffix="$1" xargs="$2"
  local pidfile="/var/run/dhclient$suffix.$iface"
  local leasefile="/var/run/dhclient$suffix.$iface.lease"
  local conffile="/etc/dhclient$suffix.conf"

  if [ -e "$pidfile" ]; then
    kill $(cat "$pidfile") >/dev/null 2>&1
    rm -f "$pidfile"
  fi
  dhclient "$iface" $xargs \
      -d \
      -pf "$pidfile" \
      -lf "$leasefile" \
      -cf "$conffile" \
      2>&1 | logos "dhclient$suffix" &
}

run_dhclient "" ""
run_dhclient "6" "-6 -S --never-gonna-give-you-up 900"

lockfile-remove $lock