#!/bin/sh # Release IP and shutdown udhcpc. # NOTE: Save our resolv.conf to avoid ending up with an empty one, in case the DHCP client wipes it on release (#6424). cp -a "/etc/resolv.conf" "/tmp/resolv.ko" old_hash="$(md5sum "/etc/resolv.conf" | cut -f1 -d' ')" if [ -x "/sbin/dhcpcd" ]; then dhcpcd -d -k "${INTERFACE}" killall -q -TERM udhcpc default.script else killall -q -TERM udhcpc default.script dhcpcd ifconfig "${INTERFACE}" 0.0.0.0 fi # NOTE: dhcpcd -k waits for the signalled process to die, but busybox's killall doesn't have a -w, --wait flag, # so we have to wait for udhcpc to die ourselves... # NOTE: But if all is well, there *isn't* any udhcpc process or script left to begin with... kill_timeout=0 while pkill -0 udhcpc; do # Stop waiting after 5s if [ ${kill_timeout} -ge 20 ]; then break fi usleep 250000 kill_timeout=$((kill_timeout + 1)) done new_hash="$(md5sum "/etc/resolv.conf" | cut -f1 -d' ')" # Restore our network-specific resolv.conf if the DHCP client wiped it when releasing the lease... if [ "${new_hash}" != "${old_hash}" ]; then mv -f "/tmp/resolv.ko" "/etc/resolv.conf" else rm -f "/tmp/resolv.ko" fi