#!/bin/sh

make_resolv_conf() {
  if [ "x$new_domain_name" != x ] && [ x"$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
      # If the nameserver has a link-local address
      # add a <zone_id> (interface name) to it.
      case $nameserver in
	fe80:*) zone_id="%$interface";;
	FE80:*) zone_id="%$interface";;
	*)      zone_id="";;
      esac
      echo nameserver ${nameserver}$zone_id >> /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
}

# This function was largely borrowed from dhclient-script that
# ships with Centos, authored by Jiri Popelka and David Cantrell
# of Redhat. Thanks guys.
add_ipv6_addr_with_DAD() {
    ifconfig ${interface} inet6 ${new_ip6_address}/${new_ip6_prefixlen} alias

    if [ ${dad_wait_time} -le 0 ]
    then
        # if we're not waiting for DAD, assume we're good
        return 0
    fi

    # Repeatedly test whether newly added address passed
    # duplicate address detection (DAD)
    for i in $(seq 1 ${dad_wait_time}); do
        sleep 1 # give the DAD some time

        addr=$(ifconfig ${interface} \
            | grep "${new_ip6_address} prefixlen ${new_ip6_prefixlen}")

        # tentative flag == DAD is still not complete
        tentative=$(echo "${addr}" | grep tentative)
        # dadfailed flag == address is already in use somewhere else
        dadfailed=$(echo "${addr}" | grep duplicated)

        if [ -n "${dadfailed}" ] ; then
            # dad failed, remove the address
            ifconfig ${interface} inet6 ${new_ip6_address}/${new_ip6_prefixlen} -alias
            exit_with_hooks 3
        fi

        if [ -z "${tentative}" ] ; then
            if [ -n "${addr}" ]; then
                # DAD is over
                return 0
            else
                # address was auto-removed (or not added at all)
                exit_with_hooks 3
            fi
        fi
    done

    return 0
}

# 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
  fi
fi

if [ x$new_network_number != x ]; then
   echo New Network Number: $new_network_number
fi

if [ x$new_broadcast_address != x ]; then
 echo New Broadcast Address: $new_broadcast_address
  new_broadcast_arg="broadcast $new_broadcast_address"
fi
if [ x$old_broadcast_address != x ]; then
  old_broadcast_arg="broadcast $old_broadcast_address"
fi
if [ x$new_subnet_mask != x ]; then
  new_netmask_arg="netmask $new_subnet_mask"
fi
if [ x$old_subnet_mask != x ]; then
  old_netmask_arg="netmask $old_subnet_mask"
fi
if [ x$alias_subnet_mask != x ]; then
  alias_subnet_arg="netmask $alias_subnet_mask"
fi
 if [ x$new_interface_mtu != x ]; then
   mtu_arg="mtu $new_interface_mtu"
 fi
if [ x$IF_METRIC != x ]; then
  metric_arg="metric $IF_METRIC"
fi

if [ 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 0
fi

###
### 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 0
fi

if [ 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 $mtu_arg $metric_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 $2
	shift; shift
      done
    fi
  else                                                                        
    # we haven't changed the address, have we changed other options           
    # that we wish to update?
    if [ x$new_routers != x ] && [ x$new_routers != x$old_routers ] ; then
      # if we've changed routers delete the old and add the new.
      $LOGGER "New Routers: $new_routers"
      for router in $old_routers; do
        route delete default $router >/dev/null 2>&1
      done
      for router in $new_routers; do
        route add default $router >/dev/null 2>&1
      done
    fi
  fi
  if [ x$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 0
fi

if [ 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 0
fi

if [ 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 $mtu_arg $metric_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 1
fi

###
### DHCPv6 Handlers
###

if [ ${reason} = PREINIT6 ] ; then
  # Ensure interface is up.
  ifconfig ${interface} up

  # XXX: Remove any stale addresses from aborted clients.

  # We need to give the kernel some time to active interface
  interface_up_wait_time=5
  for i in $(seq 0 ${interface_up_wait_time})
  do
      ifconfig ${interface} | grep inactive >/dev/null 2>&1
      if [ $? -ne 0 ]; then
          break;
      fi
      sleep 1
  done

  # Wait for duplicate address detection for this interface if the
  # --dad-wait-time parameter has been specified and is greater than
  # zero.
  if [ ${dad_wait_time} -gt 0 ]; then
      # Check if any IPv6 address on this interface is marked as
      # tentative.
      ifconfig ${interface} | grep inet6 | grep tentative \
          >/dev/null 2>&1
      if [ $? -eq 0 ]; then
          # Wait for duplicate address detection to complete or for
          # the timeout specified as --dad-wait-time.
          for i in $(seq 0 $dad_wait_time)
          do
              # We're going to poll for the tentative flag every second.
              sleep 1
              ifconfig ${interface} | grep inet6 | grep tentative \
                  >/dev/null 2>&1
              if [ $? -ne 0 ]; then
                  break;
              fi
          done
      fi
  fi

  exit_with_hooks 0
fi

if [ x${old_ip6_prefix} != x ] || [ x${new_ip6_prefix} != x ] ; then
    echo Prefix ${reason} old=${old_ip6_prefix} new=${new_ip6_prefix}

    exit_with_hooks 0
fi

if [ ${reason} = BOUND6 ] ; then
  if [ x${new_ip6_address} = x ] || [ x${new_ip6_prefixlen} = x ] ; then
    exit_with_hooks 2;
  fi

  # Add address to interface, check for DAD if dad_wait_time > 0
  add_ipv6_addr_with_DAD

  # Check for nameserver options.
  make_resolv_conf

  exit_with_hooks 0
fi

if [ ${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 0
fi

if [ ${reason} = DEPREF6 ] ; then
  if [ x${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 0
fi

if [ ${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 -alias ${old_ip6_address}/${old_ip6_prefixlen}

  exit_with_hooks 0
fi

exit_with_hooks 0