#!/bin/sh
# dhclient-script for Linux. Dan Halbert, March, 1997.
# Updated for Linux 2.[12] by Brian J. Murrell, January 1999.
# No guarantees about this. I'm a novice at the details of Linux
# networking.

# Notes:

# 0. This script is based on the netbsd script supplied with dhcp-970306.

# 1. ifconfig down apparently deletes all relevant routes and flushes
# the arp cache, so this doesn't need to be done explicitly.

# 2. The alias address handling here has not been tested AT ALL.
# I'm just going by the doc of modern Linux ip aliasing, which uses
# notations like eth0:0, eth0:1, for each alias.

# 3. I have to calculate the network address, and calculate the broadcast
# address if it is not supplied. This might be much more easily done
# by the dhclient C code, and passed on.

# 4. TIMEOUT not tested. ping has a flag I don't know, and I'm suspicious
# of the $1 in its args.

# Must be used on exit.   Invokes the local dhcp client exit hooks, if any.
exit_with_hooks() {
  exit_status=$1
  if [ -x /etc/dhclient-exit-hooks ]; then
    . /etc/dhclient-exit-hooks
  fi
# probably should do something with exit status of the local script
  exit $exit_status
}

########### Modified by Oliver Dawid 05.04.2001
########### for fli4l - see # fli4l - Comments
########### $Id$

########### fli4l
########### Don't create a /etc/resolv.conf - never!
########### 

make_resolv_conf() {
#  echo search $new_domain_name >/etc/resolv.conf
#  for nameserver in $new_domain_name_servers; do
#    echo nameserver $nameserver >>/etc/resolv.conf
#  done
    echo "skipping generation of /etc/resolv.conf"
}

# 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

########### fli4l
########### because the original uname -r does not work
########### properly, get it from /etc/kernel-major

eval release=`cat /etc/kernel-major`
relminor=`echo $release | cut -d "." -f2`
relmajor=`echo $release | cut -d "." -f1`

if [ x$new_broadcast_address != x ]; then
  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_subnet_arg=`netcalc netmaskbits $new_subnet_mask`
fi
if [ x$old_subnet_mask != x ]; then
  old_subnet_arg=`netcalc netmaskbits $new_subnet_mask`
fi
if [ x$alias_subnet_mask != x ]; then
  alias_subnet_arg=`netcalc netmaskbits $alias_subnet_mask`
fi

if [ x$reason = xMEDIUM ]; then
  # Linux doesn't do mediums (ok, ok, media).
  exit_with_hooks 0
fi

if [ x$reason = xPREINIT ]; then
  if [ x$alias_ip_address != x ]; then
    # Bring down alias interface. Its routes will disappear too.
    ip link set $interface down
  fi
  if [ $relmajor -lt 2 ] || ( [ $relmajor -eq 2 ] && [ $relminor -eq 0 ] )
   then
    ip link set $interface up
    ip addr add 0.0.0.0/32 broadcast 255.255.255.255 label $interface dev $interface
    # Add route to make broadcast work. Do not omit netmask.
    ip route add default dev $interface
  else
    ip link set $interface up
  fi

  # We need to give the kernel some time to get the interface up.
  sleep 1

  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

  if [ x$old_ip_address != x ] && [ x$old_ip_address != x$new_ip_address ]; then
    # IP address changed. Bringing down the interface will delete all routes,
    # and clear the ARP cache.
    ip link set $interface down

  fi
  if [ x$old_ip_address = x ] || [ x$old_ip_address != x$new_ip_address ] || \
     [ x$reason = xBOUND ] || [ x$reason = xREBOOT ]; then

    ip link set $interface up
    ip addr add $new_ip_address/$new_subnet_arg $new_broadcast_arg label $interface dev $interface
    # Add a network route to the computed network address.
    if [ $relmajor -lt 2 ] || \
    ( [ $relmajor -eq 2 ] && [ $relminor -eq 0 ] ); then
      ip route add via $new_network_number/$new_subnet_arg dev $interface
    fi
    if [ -f /var/run/$interface.gw ]; then
      echo $new_routers > /var/run/$interface.gw
      for router in $new_routers; do
        ip route add default via $router
      done
    fi
  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$old_ip_address != x ]; then
    # Shut down interface, which will delete routes and clear arp cache.
    ip link set $interface down
  fi
  exit_with_hooks 0
fi

if [ x$reason = xTIMEOUT ]; then
  set $new_routers
    if [ $relmajor -lt 2 ] || \
    ( [ $relmajor -eq 2 ] && [ $relminor -eq 0 ] ); then
      ip route add $new_network_number dev $interface
    fi
    for router in $new_routers; do
      ip route add default via $router
    done
    make_resolv_conf
    exit_with_hooks 0
  ip link set $interface down
  exit_with_hooks 1
fi

exit_with_hooks 0