chromeos-base/chromeos-initramfs/files/udhcpc.script

#!/bin/sh -e

# udhcpc script from busybox example
# http://git.busybox.net/busybox/tree/examples/udhcp/simple.script

# This script is needed for busybox udhcpc to work. In initramfs, udhcpc and
# this script are used to obtain IP address from DHCP server.

RESOLV_CONF="/etc/resolv.conf"

[ -n "$1" ] || { echo "Error: should be called from udhcpc"; exit 1; }

NETMASK=""
[ -n "$subnet" ] && NETMASK="netmask $subnet"
BROADCAST="broadcast +"
[ -n "$broadcast" ] && BROADCAST="broadcast $broadcast"

case "$1" in

  deconfig)
    echo "Setting IP address 0.0.0.0 on $interface"
    ifconfig $interface 0.0.0.0
    ;;

  renew|bound)
    echo "Setting IP address $ip on $interface"
    ifconfig $interface $ip $NETMASK $BROADCAST

    if [ -n "$router" ]; then
      echo "Deleting routers"
      while route del default gw 0.0.0.0 dev $interface ; do
        :
      done

      metric=0
      for i in $router; do
        echo "Adding router $i"
        route add default gw $i dev $interface metric $((metric))
        : $((metric += 1))
      done
    fi

    echo "Recreating $RESOLV_CONF"
    printf "" > $RESOLV_CONF-$$
    [ -n "$domain" ] && echo "search $domain" >> $RESOLV_CONF-$$
    for i in $dns; do
      echo " Adding DNS server $i"
      echo "nameserver $i" >> $RESOLV_CONF-$$
    done
    mv $RESOLV_CONF-$$ $RESOLV_CONF
    ;;

esac

exit 0