#!/bin/bash
#============================================================================
# xen-dhcpd
#
# Version = 1.0.2
# Date = 2007-09-14
#
# Maintainer(s) = Ron Terry - ron (at) pronetworkconsulting (dot) com
#
# Contributers  = Mike Friesenegger - mfriesenegger (at) novell (dot) com
#
# The latest version can be found at:
#
#    http://pronetworkconsulting.com/linux/scripts/network-multinet.html
#
# Description:
#
# This script configures and enables the DHCP server for the networks on 
#  which it has been defined to run in the Xen network condifuration script 
#  config file.
#
#============================================================================

####  Read config files and set variables  ##################################

# Source the configuration File

. /etc/sysconfig/xend

DHCPD_CONF_FILE="/etc/dhcpd.conf"
CONF_FILE_PATH="/etc/xen/conf"
SYSCONFIG_FILE="/etc/sysconfig/dhcpd"

####  Script Functions  #####################################################

do_we_start_dhcpd() {
  if ! echo $LOCAL_BRIDGE_LIST|grep -q "dhcp-on" || ! echo $NETWORK_LIST|grep -q "dhcp-on"
  then
    echo " The DHCP daemon is not configured on any network"
    echo ""
    echo " Not starting dhcpd for Xen"
    echo "============================================================"
    exit 1
  fi
}

cleanup_old_dhcp_config_files() {
  # A bit of housekeeping, cleaning up old configuration files
#echo "cleaning up /etc/xen/conf/"
#read
  rm -rf /etc/xen/conf/*
#echo "cleaning up /etc/dhcpd-xen*"
#read
  rm -rf /etc/dhcpd-xen*
#echo "cleaning up /etc/sysconfig/network/ifcfg-veth-id*"
#read
  rm -rf /etc/sysconfig/network/ifcfg-veth-id*
}

create_xen_dhcp_config_files() {

  # backup original dhcpd sysconfig file
#echo "backup original dhcpd sysconfig file"
#read
  cp "$SYSCONFIG_FILE" "$CONF_FILE_PATH"/dhcpd.xensave
  cp "$DHCPD_CONF_FILE" "$CONF_FILE_PATH/dhcpd.conf.xensave" 

  for IFACE in $LOCAL_BRIDGE_LIST
  do
    # If DHCPON is set to dhcp-off, skip creating config files for vethX
    #---------------------------------------------------------------------
    local DHCPON=`echo $IFACE|cut -d "," -f 5`
    test "$DHCPON" = "dhcp-off" && continue

    # Set local function variables
    #---------------------------------------------------------------------
    local DEV=`echo $IFACE|cut -d "," -f 1`
    local MAC=`echo $IFACE|cut -d "," -f 2`
    local IPCIDR=`echo $IFACE|cut -d "," -f 3`
    local IPADDR=`echo $IPCIDR|cut -d "/" -f 1`
    local RANGE="`echo $IPADDR|cut -d "." -f 1,2,3`.`echo $XEN_DHCP_RANGE|cut -d "-" -f 1` - `echo $IPADDR|cut -d "." -f 1,2,3`.`echo $XEN_DHCP_RANGE|cut -d "-" -f 2`"
    local SUBNET=`ipcalc -n -b $IPCIDR|grep "Network:"|cut -d ":" -f 2|cut -d "/" -f 1`
    local NETMASK=`ipcalc -n -b $IPCIDR|grep "Netmask:"|cut -d ":" -f 2|cut -d "=" -f 1`
    local BRIDGE_NUM=${DEV##${DEV%%[0-9]*}}
    local BR_NAME=$BRIDGE_NAME$BRIDGE_NUM
    
    case $XEN_DHCP_DNS_SERVERS in
      gateway)
        # Use Dom0 as the DNS server
        local DNS=$IPADDR
      ;;
      *)
        # Specify DNS server(s)
        if test `echo $XEN_DHCP_DNS_SERVERS|grep -c ","`
        then
          local DNS=`echo $XEN_DHCP_DNS_SERVERS|sed "s/,/, /"`
        else
          local DNS=`echo $XEN_DHCP_DNS_SERVERS`
        fi
      ;;
    esac
    
    # echo out what we are doing
    #---------------------------------------------------------------------
    echo "------------------------------------------------------------"
    echo " Configuring dhcpd for bridge:  $BR_NAME"
    echo "    on Interface: $DEV"
    echo "    -------------------"
    echo "    Subnet:       $SUBNET"
    echo "    Netmask:      $NETMASK"
    echo "    Range:        $RANGE"
    echo "    DNS Servers:  $DNS"
    echo "    Gateway:      $IPADDR"
    echo "------------------------------------------------------------"
    
    # Create network ifcfg-veth config file
    # THIS IS NOT NECESSARY UNLESS YOU WANT TO SEE THE NIC IN YAST TOOLS
    #---------------------------------------------------------------------
    echo "NAME='XEN Virtual Ethernet - $DEV'" > /etc/sysconfig/network/ifcfg-veth-id-$MAC

    # Create the dhcpd-xen.vethX.conf file
    #---------------------------------------------------------------------
    echo "ddns-update-style none;" > /etc/dhcpd-xen.$DEV.conf
    echo "subnet $SUBNET netmask $NETMASK {" >> /etc/dhcpd-xen.$DEV.conf
    echo "  range `echo $RANGE | tr -d -`;" >> /etc/dhcpd-xen.$DEV.conf
    echo "  default-lease-time 14400;" >> /etc/dhcpd-xen.$DEV.conf
    echo "  max-lease-time 14400;" >> /etc/dhcpd-xen.$DEV.conf
    echo "  option domain-name-servers $DNS;" >> /etc/dhcpd-xen.$DEV.conf
    echo "  option routers $IPADDR;" >> /etc/dhcpd-xen.$DEV.conf
    echo "}" >> /etc/dhcpd-xen.$DEV.conf

    # edit the dhcpd sysconfig file for xen
    #---------------------------------------------------------------------
#echo "editing DHCPD_INTERFACE in $SYSCONFIG_FILE"
#read
    sed -i "s/^DHCPD_INTERFACE=\"\([^\"]*\)\"/DHCPD_INTERFACE=\"\1 veth-id-$MAC\"/" $SYSCONFIG_FILE
#echo "editing DHCPD_CONF_INCLUDE_FILES in $SYSCONFIG_FILE"
#read
    sed -i "s/^DHCPD_CONF_INCLUDE_FILES=\"\([^\"]*\)\"/DHCPD_CONF_INCLUDE_FILES=\"\1\/etc\/dhcpd-xen.$DEV.conf\"/" $SYSCONFIG_FILE

    # edit the dhcpd.conf file to include additional dhcpd configs for xen
    #---------------------------------------------------------------------
    echo "include \"/etc/dhcpd-xen.$DEV.conf\";" >> $DHCPD_CONF_FILE

  done
}

restore_original_dhcp_config_files() {
  # Restore the original dhcpd.conf file
  #---------------------------------------------------------------------
#echo "restoring original dhcpd.conf"
#read
  mv $CONF_FILE_PATH/dhcpd.xensave $SYSCONFIG_FILE > /dev/null 2>&1
  mv $CONF_FILE_PATH/dhcpd.conf.xensave $DHCPD_CONF_FILE > /dev/null 2>&1
  # FIXME:  should I be doing this in the for loop below using sed?

  for IFACE in $LOCAL_BRIDGE_LIST
  do
    # If DHCPON is set to dhcp-off, skip creating config files for vethX
    #---------------------------------------------------------------------
    local DHCPON=`echo $IFACE|cut -d "," -f 5`
    test "$DHCPON" = "dhcp-off" && continue

    # Set local function variables
    #---------------------------------------------------------------------
    local DEV=`echo $IFACE|cut -d "," -f 1`
    local MAC=`echo $IFACE|cut -d "," -f 2`
    local IPCIDR=`echo $IFACE|cut -d "," -f 3`
    local IPADDR=`echo $IPCIDR|cut -d "/" -f 1`
    local RANGE="`echo $IPADDR|cut -d "." -f 1,2,3`.`echo $XEN_DHCP_RANGE|cut -d "-" -f 1` `echo $IPADDR|cut -d "." -f 1,2,3`.`echo $XEN_DHCP_RANGE|cut -d "-" -f 2`"
    local SUBNET=`ipcalc -n -b $IPCIDR|grep "Network:"|cut -d ":" -f 2|cut -d "/" -f 1`
    local NETMASK=`ipcalc -n -b $IPCIDR|grep "Netmask:"|cut -d ":" -f 2|cut -d "=" -f 1`
    
    # echo out what we are doing
    #---------------------------------------------------------------------
    echo " Removing dhcpd configuration for bridge:  $BR_NAME"
    echo "------------------------------------------------------------"
    
    # Delete network ifcfg-veth config file
    #---------------------------------------------------------------------
#echo "deleteing ifcfg-veth-$MAC"
#read
    rm -rf /etc/sysconfig/network/ifcfg-veth-id-$MAC
    
    # Delete the dhcpd-xen.vethX.conf file
    #---------------------------------------------------------------------
#echo "deleteing dhcpd-xen.$DEV.conf"
#read
    rm -rf /etc/dhcpd-xen.$DEV.conf
    
    # Restore the original dhcpd.conf file
    #---------------------------------------------------------------------
    # FIXME:  should I be doing this with sed here instead?
  done
}

####  Start, Stop, Status Functions  ########################################

start_xen_dhcpd() {
  do_we_start_dhcpd
  #cleanup_old_dhcp_config_files
  create_xen_dhcp_config_files
  echo ""
  echo " Starting the DHCP Daemon on configured networks"
  /etc/init.d/dhcpd restart
}

stop_xen_dhcpd() {
  #/etc/init.d/dhcpd stop
  restore_original_dhcp_config_files
  if grep -Rl "Short-Description:.*DHCP Server" /etc/init.d/rc`runlevel|cut -d " " -f 2`.d|grep -q "S"
  then
    /etc/init.d/dhcpd restart
  fi
}

xen_dhcpd_status () {
  /etc/init.d/dhcpd status
}

####  Main Code Body  #######################################################

# Check to see if dhcpd and ipcalc are installed
if [ -e /usr/sbin/dhcpd ] && [ -e /etc/init.d/dhcpd ] && [ -e $SYSCONFIG_FILE ] && [ -e /usr/bin/ipcalc ] 
then
  echo ""
  echo "============================================================"
  
  case $1 in
    start)
      start_xen_dhcpd
      exit 0
    ;;
    stop)
      stop_xen_dhcpd
      exit 0
    ;;
    restart)
      stop_xen_dhcpd
      start_xen_dhcpd
      exit 0
    ;;
    status)
      /etc/init.d/dhcpd status
      exit 0
    ;;
  esac
  
  echo "============================================================"
  
else
  echo ""
  echo "============================================================"
  if [ ! -e /usr/sbin/dhcpd ] && [ ! -e /etc/init.d/dhcpd ] && [ ! -e $SYSCONFIG_FILE ]
  then
    echo ""
    echo " The DHCP Daemon is not installed or is missing needed files."
  fi
  if [ ! -e /usr/bin/ipcalc ]
  then
    echo ""
    echo " The ipcalc package is not installed."
  fi
  echo "" 
  echo " Skipping starting dhcpd for Xen"
  echo "============================================================"
  exit 1
fi