#!/bin/shmake_resolv_conf() {  if [ x"$new_domain_name_servers" != x ]; then    cat /dev/null > /etc/resolv.conf.dhclient    if [ "x$new_domain_search" != x ]; then      echo search $new_domain_search >> /etc/resolv.conf.dhclient    elif [ "x$new_domain_name" != x ]; then      # Note that the DHCP 'Domain Name Option' is really just a domain      # name, and that this practice of using the domain name option as      # a search path is both nonstandard and deprecated.      echo search $new_domain_name >> /etc/resolv.conf.dhclient    fi    for nameserver in $new_domain_name_servers; do      echo nameserver $nameserver >> /etc/resolv.conf.dhclient    done    mv /etc/resolv.conf.dhclient /etc/resolv.conf  elif [ "x${new_dhcp6_name_servers}" != x ] ; then    cat /dev/null > /etc/resolv.conf.dhclient6    chmod 644 /etc/resolv.conf.dhclient6    if [ "x${new_dhcp6_domain_search}" != x ] ; then      echo search ${new_dhcp6_domain_search} >> /etc/resolv.conf.dhclient6    fi    for nameserver in ${new_dhcp6_name_servers} ; do      echo nameserver ${nameserver} >> /etc/resolv.conf.dhclient6    done    mv /etc/resolv.conf.dhclient6 /etc/resolv.conf  fi}# Must be used on exit.   Invokes the local dhcp client exit hooks, if any.exit_with_hooks() {  exit_status=$1  if [ -f /etc/dhclient-exit-hooks ]; then    . /etc/dhclient-exit-hooks  fi# probably should do something with exit status of the local script  exit $exit_status}# Invoke the local dhcp client enter hooks, if they exist.if [ -f /etc/dhclient-enter-hooks ]; then  exit_status=0  . /etc/dhclient-enter-hooks  # allow the local script to abort processing of this state  # local script must set exit_status variable to nonzero.  if [ $exit_status -ne 0 ]; then    exit $exit_status  fifiif [ x$new_network_number != x ]; then   echo New Network Number: $new_network_numberfiif [ x$new_broadcast_address != x ]; then echo New Broadcast Address: $new_broadcast_address  new_broadcast_arg="broadcast $new_broadcast_address"fiif [ x$old_broadcast_address != x ]; then  old_broadcast_arg="broadcast $old_broadcast_address"fiif [ x$new_subnet_mask != x ]; then  new_netmask_arg="netmask $new_subnet_mask"fiif [ x$old_subnet_mask != x ]; then  old_netmask_arg="netmask $old_subnet_mask"fiif [ x$alias_subnet_mask != x ]; then  alias_subnet_arg="netmask $alias_subnet_mask"fiif [ x$reason = xMEDIUM ]; then  eval "ifconfig $interface $medium"  eval "ifconfig $interface inet -alias 0.0.0.0 $medium" >/dev/null 2>&1  sleep 1  exit_with_hooks 0fi###### DHCPv4 Handlers###if [ x$reason = xPREINIT ]; then  if [ x$alias_ip_address != x ]; then    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1  fi  ifconfig $interface inet 0.0.0.0 netmask 0.0.0.0 \		broadcast 255.255.255.255 up  exit_with_hooks 0fiif [ x$reason = xARPCHECK ] || [ x$reason = xARPSEND ]; then  exit_with_hooks 0;fi  if [ x$reason = xBOUND ] || [ x$reason = xRENEW ] || \   [ x$reason = xREBIND ] || [ x$reason = xREBOOT ]; then  current_hostname=`hostname`  if [ x$current_hostname = x ] || \     [ x$current_hostname = x$old_host_name ]; then    if [ x$current_hostname = x ] || \       [ x$new_host_name != x$old_host_name ]; then      hostname $new_host_name    fi  fi      if [ x$old_ip_address != x ] && [ x$alias_ip_address != x ] && \		[ x$alias_ip_address != x$old_ip_address ]; then    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1  fi  if [ x$old_ip_address != x ] && [ x$old_ip_address != x$new_ip_address ]   then    eval "ifconfig $interface inet -alias $old_ip_address $medium"    route delete $old_ip_address 127.1 >/dev/null 2>&1    for router in $old_routers; do      route delete default $router >/dev/null 2>&1    done    if [ "$old_static_routes" != "" ]; then      set $old_static_routes      while [ $# -gt 1 ]; do	route delete $1 $2	shift; shift      done    fi    arp -n -a | sed -n -e 's/^.*(\(.*\)) at .*$/arp -n -d \1/p' |sh  fi  if [ x$old_ip_address = x ] || [ x$old_ip_address != x$new_ip_address ] || \     [ x$reason = xBOUND ] || [ x$reason = xREBOOT ]; then    eval "ifconfig $interface inet $new_ip_address $new_netmask_arg \					$new_broadcast_arg $medium"    route add $new_ip_address 127.1 >/dev/null 2>&1    for router in $new_routers; do      route add default $router >/dev/null 2>&1    done    if [ "$new_static_routes" != "" ]; then      set $new_static_routes      while [ $# -gt 1 ]; do	route add $1 $2	shift; shift      done    fi  fi  if [ x$new_ip_address != x$alias_ip_address ] && [ x$alias_ip_address != x ];   then    ifconfig $interface inet alias $alias_ip_address $alias_subnet_arg    route add $alias_ip_address 127.0.0.1  fi  make_resolv_conf  exit_with_hooks 0fiif [ x$reason = xEXPIRE ] || [ x$reason = xFAIL ] || [ x$reason = xRELEASE ] \   || [ x$reason = xSTOP ]; then  if [ x$alias_ip_address != x ]; then    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1  fi  if [ x$old_ip_address != x ]; then    eval "ifconfig $interface inet -alias $old_ip_address $medium"    route delete $old_ip_address 127.1 >/dev/null 2>&1    for router in $old_routers; do      route delete default $router >/dev/null 2>&1    done    if [ "$old_static_routes" != "" ]; then      set $old_static_routes      while [ $# -gt 1 ]; do	route delete $1 $2	shift; shift      done    fi    arp -n -a | sed -n -e 's/^.*(\(.*\)) at .*$/arp -n -d \1/p' \						|sh >/dev/null 2>&1  fi  if [ x$alias_ip_address != x ]; then    ifconfig $interface inet alias $alias_ip_address $alias_subnet_arg    route add $alias_ip_address 127.0.0.1  fi  exit_with_hooks 0fiif [ x$reason = xTIMEOUT ]; then  if [ x$alias_ip_address != x ]; then    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1  fi  eval "ifconfig $interface inet $new_ip_address $new_netmask_arg \					$new_broadcast_arg $medium"  sleep 1  if [ "$new_routers" != "" ]; then    set $new_routers    if ping -q -c 1 -w 1 $1; then      if [ x$new_ip_address != x$alias_ip_address ] && \			[ x$alias_ip_address != x ]; then	ifconfig $interface inet alias $alias_ip_address $alias_subnet_arg	route add $alias_ip_address 127.0.0.1      fi      route add $new_ip_address 127.1 >/dev/null 2>&1      for router in $new_routers; do	route add default $router >/dev/null 2>&1      done      set $new_static_routes      while [ $# -gt 1 ]; do	route add $0 $1	shift; shift      done      make_resolv_conf      exit_with_hooks 0    fi  fi  eval "ifconfig $interface inet -alias $new_ip_address $medium"  for router in $old_routers; do    route delete default $router >/dev/null 2>&1  done  if [ "$old_static_routes" != "" ]; then    set $old_static_routes    while [ $# -gt 1 ]; do      route delete $1 $2      shift; shift    done  fi  arp -n -a | sed -n -e 's/^.*(\(.*\)) at .*$/arp -n -d \1/p' \							|sh >/dev/null 2>&1  exit_with_hooks 1fi###### DHCPv6 Handlers###if [ ${reason} = PREINIT6 ] ; then  # Ensure interface is up.  ifconfig ${interface} up  # XXX: Remove any stale addresses from aborted clients.  exit_with_hooks 0fiif [ ${reason} = BOUND6 ] ; then  if [ x${new_ip6_address} = x ] || [ x${new_ip6_prefixlen} = x ] ; then    exit_with_hooks 2;  fi  ifconfig ${interface} inet6 add ${new_ip6_address}/${new_ip6_prefixlen}  # Check for nameserver options.  make_resolv_conf  exit_with_hooks 0fiif [ ${reason} = RENEW6 ] || [ ${reason} = REBIND6 ] ; then  # Make sure nothing has moved around on us.  # Nameservers/domains/etc.  if [ "x${new_dhcp6_name_servers}" != "x${old_dhcp6_name_servers}" ] ||     [ "x${new_dhcp6_domain_search}" != "x${old_dhcp6_domain_search}" ] ; then    make_resolv_conf  fi  exit_with_hooks 0fiif [ ${reason} = DEPREF6 ] ; then  if [ x${new_ip6_prefixlen} = x ] ; then    exit_with_hooks 2;  fi  # XXX:  # There doesn't appear to be a way to update an addr to indicate  # preference.  exit_with_hooks 0fiif [ ${reason} = EXPIRE6 -o ${reason} = RELEASE6 -o ${reason} = STOP6 ] ; then  if [ x${old_ip6_address} = x ] || [ x${old_ip6_prefixlen} = x ] ; then    exit_with_hooks 2;  fi  ifconfig ${interface} inet6 delete ${old_ip6_address}/${old_ip6_prefixlen}  exit_with_hooks 0fiexit_with_hooks 0