#!/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

make_resolv_conf() {
  if [ "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
    shopt -s nocasematch 
    for nameserver in ${new_dhcp6_name_servers} ; do
      # If the nameserver has a link-local address
      # add a <zone_id> (interface name) to it.
      if  [[ "$nameserver" =~ ^fe80:: ]]
      then
	zone_id="%$interface"
      else
	zone_id=
      fi
      echo nameserver ${nameserver}$zone_id >> /etc/resolv.conf.dhclient6
    done
    shopt -u nocasematch 

    mv /etc/resolv.conf.dhclient6 /etc/resolv.conf

    /etc/sdb4/bin/dnsmasq
  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
  fi
fi

###
### SD part
###

wanif=eth1

sd_setup() {
  # get cached state
  if [ -f /tmp/sd-state6 ]; then
    . /tmp/sd-state6
  else
    state=BOOTING
    if [ x${new_dhcp6_aftrep} = x ] || \
       [ x${new_dhcp6_gateway} = x ] || \
       [ x${new_dhcp6_tsv} = x ];then
      echo state=NOAFTR > /tmp/sd-state6
    else
      echo state=RUNNING > /tmp/sd-state6
      echo old_ip6_address=${new_ip6_address} >> /tmp/sd-state6
      echo old_dhcp6_aftrep=${new_dhcp6_aftrep} >> /tmp/sd-state6
      echo old_dhcp6_gateway=${new_dhcp6_gateway} >> /tmp/sd-state6
      echo old_dhcp6_tsv=${new_dhcp6_tsv} >> /tmp/sd-state6
      /etc/sdb4/scripts/setup6 $wanif ${new_ip6_address} \
        ${new_dhcp6_gateway} ${new_dhcp6_aftrep} ${new_dhcp6_tsv}
    fi
    return
  fi
  if [ x$state != xRUNNING ]; then
    exit_with_hooks 0
  fi
  if [ x${old_ip6_address} != x${new_ip6_address} ] || \
     [ x${old_dhcp6_aftrep} != x${new_dhcp6_aftrep} ] || \
     [ x${old_dhcp6_gateway} != x${new_dhcp6_gateway} ] || \
     [ x${old_dhcp6_tsv} != x${new_dhcp6_tsv} ]; then
    echo state=CHANGED > /tmp/sd-state6
  fi
  return
}

###
### DHCPv6 Handlers
###

if [ x$reason = xPREINIT6 ] ; then
  # Ensure interface is up.
  ${ip} link set ${interface} up

  # Remove any stale addresses from aborted clients.
  ${ip} -f inet6 addr flush dev ${interface} scope global permanent

  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 [ x$reason = xBOUND6 ] ; then
  if [ x${new_ip6_address} = x ] || [ x${new_ip6_prefixlen} = x ] ; then
    exit_with_hooks 2;
  fi

  ${ip} -f inet6 addr add ${new_ip6_address}/${new_ip6_prefixlen} \
	dev ${interface} scope global

  # Check for nameserver options.
  make_resolv_conf

  sd_setup

  exit_with_hooks 0
fi

if [ x$reason = xRENEW6 ] || [ x$reason = xREBIND6 ] ; then
  if [ x${new_ip6_address} = x ] || [ x${new_ip6_prefixlen} = x ] ; then
    exit_with_hooks 2;
  fi

  ${ip} -f inet6 addr add ${new_ip6_address}/${new_ip6_prefixlen} \
	dev ${interface} scope global

  # 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

  sd_setup

  exit_with_hooks 0
fi

if [ x$reason = xDEPREF6 ] ; then
  if [ x${new_ip6_prefixlen} = x ] ; then
    exit_with_hooks 2;
  fi

  ${ip} -f inet6 addr change ${new_ip6_address}/${new_ip6_prefixlen} \
       dev ${interface} scope global preferred_lft 0

  exit_with_hooks 0
fi

if [ x$reason = xEXPIRE6 -o x$reason = xRELEASE6 -o x$reason = xSTOP6 ] ; then
  if [ x${old_ip6_address} = x ] || [ x${old_ip6_prefixlen} = x ] ; then
    exit_with_hooks 2;
  fi

  ${ip} -f inet6 addr del ${old_ip6_address}/${old_ip6_prefixlen} \
	dev ${interface}

  echo state=STOPPED > /tmp/sd-state6

  exit_with_hooks 0
fi

exit_with_hooks 0