#!/bin/bash
# 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.

# 'ip' just looks too weird.  /sbin/ip looks less weird.
ip=/sbin/ip

# 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
  fi
fi

###
### SD part
###

wanif=eth1
lanif=eth2

sd_setup() {
  # get cached state
  if [ -f /tmp/sd-state4 ]; then
    . /tmp/sd-state4
  else
    state=BOOTING
    if [ x$new_port_range_min = x ] || [ x$new_port_range_max = x ]; then
      echo state=NORANGE > /tmp/sd-state4
    else
      echo state=RUNNING > /tmp/sd-state4
      echo old_ip_address=$new_ip_address >> /tmp/sd-state4
      echo old_port_range_min=$new_port_range_min >> /tmp/sd-state4
      echo old_port_range_max=$new_port_range_max >> /tmp/sd-state4
      /etc/sdb4/scripts/setup4 $wanif $lanif $new_ip_address \
        $new_port_range_min $new_port_range_max
    fi
    return
  fi
  if [ x$state != xRUNNING ]; then
    exit_with_hooks 0
  fi
  if [ x$old_ip_address != x$new_ip_address ] || \
     [ x$old_port_range_min != x$new_port_range_min ] || \
     [ x$old_port_range_max != x$new_port_range_max ]; then
    echo state=CHANGED > /tmp/sd-state4
  fi
  return
}

###
### DHCPv4 Handlers
###

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="netmask $new_subnet_mask"
fi
if [ x$old_subnet_mask != x ]; then
  old_subnet_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
  # 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.
    ifconfig $interface:0- inet 0
  fi
  ifconfig $interface 0 up

  # 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
  current_hostname=`hostname`
  if [ x$current_hostname = x ] || \
     [ x$current_hostname = "x(none)" ] || \
     [ x$current_hostname = xlocalhost ] || \
     [ x$current_hostname = x$old_host_name ]; then
    if [ x$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
    # Possible new alias. Remove old alias.
    ifconfig $interface:0- inet 0
  fi
  if [ x$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.
    ifconfig $interface inet 0 down

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

    ifconfig $interface inet $new_ip_address $new_subnet_arg \
					$new_broadcast_arg $mtu_arg
    # Add a network route to the computed network address.
    for router in $new_routers; do
      if [ "x$new_subnet_mask" = "x255.255.255.255" ] ; then
	route add -host $router dev $interface
      fi
      route add default gw $router $metric_arg dev $interface
    done
  else
    # we haven't changed the address, have we changed other options           
    # that we wish to update?
    if [ x$new_routers != x ] && [ x$new_routers != x$old_routers ] ; then
      # if we've changed routers delete the old and add the new.
      for router in $old_routers; do
        route del default gw $router
      done
      for router in $new_routers; do
        if [ "x$new_subnet_mask" = "x255.255.255.255" ] ; then
	  route add -host $router dev $interface
	fi
	route add default gw $router $metric_arg dev $interface
      done
    fi
  fi
  if [ x$new_ip_address != x$alias_ip_address ] && [ x$alias_ip_address != x ];
   then
    ifconfig $interface:0- inet 0
    ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
    route add -host $alias_ip_address $interface:0
  fi
  sd_setup
  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
    # Turn off alias interface.
    ifconfig $interface:0- inet 0
  fi
  if [ x$old_ip_address != x ]; then
    # Shut down interface, which will delete routes and clear arp cache.
    ifconfig $interface inet 0 down
  fi
  if [ x$alias_ip_address != x ]; then
    ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
    route add -host $alias_ip_address $interface:0
  fi
  echo state=STOPPED > /tmp/sd-state4
  exit_with_hooks 0
fi

if [ x$reason = xTIMEOUT ]; then
  if [ x$alias_ip_address != x ]; then
    ifconfig $interface:0- inet 0
  fi
  ifconfig $interface inet $new_ip_address $new_subnet_arg \
					$new_broadcast_arg $mtu_arg
  set $new_routers
  if ping -q -c 1 $1; then
    if [ x$new_ip_address != x$alias_ip_address ] && \
			[ x$alias_ip_address != x ]; then
      ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
      route add -host $alias_ip_address dev $interface:0
    fi
    for router in $new_routers; do
      if [ "x$new_subnet_mask" = "x255.255.255.255" ] ; then
	route add -host $router dev $interface
      fi
      route add default gw $router $metric_arg dev $interface
    done
    exit_with_hooks 0
  fi
  ifconfig $interface inet 0 down
  exit_with_hooks 1
fi

exit_with_hooks 0