#!/usr/bin/env bash



  #
  # Copyright (C) 2010 Cloud.com, Inc.  All rights reserved.
  # 
  # This software is licensed under the GNU General Public License v3 or later.
  # 
  # It is free software: you can redistribute it and/or modify
  # it under the terms of the GNU General Public License as published by
  # the Free Software Foundation, either version 3 of the License, or any later version.
  # This program is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  # GNU General Public License for more details.
  # 
  # You should have received a copy of the GNU General Public License
  # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  #
 

# edithosts.sh -- edit the dhcphosts file on the routing domain
# $1 : the mac address
# $2 : the associated ip address
# $3 : the hostname

grep "redundant_router=1" /var/cache/cloud/cmdline > /dev/null
no_redundant=$?

wait_for_dnsmasq () {
  local _pid=$(pidof dnsmasq)
  for i in 0 1 2 3 4 5 6 7 8 9 10
  do
    sleep 1
    _pid=$(pidof dnsmasq)
    [ "$_pid" != "" ] && break;
  done
  [ "$_pid" != "" ] && return 0;
  logger -t cloud "edithosts: timed out waiting for dnsmasq to start"
  return 1
}

logger -t cloud "edithosts: update $1 $2 $3 to hosts"

[ ! -f /etc/dhcphosts.txt ] && touch /etc/dhcphosts.txt
[ ! -f /var/lib/misc/dnsmasq.leases ] && touch /var/lib/misc/dnsmasq.leases

#delete any previous entries from the dhcp hosts file
sed -i  /$1/d /etc/dhcphosts.txt 
sed -i  /$2,/d /etc/dhcphosts.txt 
sed -i  /$3,/d /etc/dhcphosts.txt 

#put in the new entry
echo "$1,$2,$3,infinite" >>/etc/dhcphosts.txt

#delete leases to supplied mac and ip addresses
sed -i  /$1/d /var/lib/misc/dnsmasq.leases 
sed -i  /"$2 "/d /var/lib/misc/dnsmasq.leases 
sed -i  /"$3 "/d /var/lib/misc/dnsmasq.leases 

#put in the new entry
echo "0 $1 $2 $3 *" >> /var/lib/misc/dnsmasq.leases

#edit hosts file as well
sed -i  /"$2 "/d /etc/hosts
sed -i  /"$3"/d /etc/hosts
echo "$2 $3" >> /etc/hosts

locked=0
if [ $no_redundant -eq 0 ]
then
#for redundant router, grap the lock to prevent racy with keepalived process
LOCK=/tmp/rrouter.lock

# Wait the lock
for i in `seq 1 5`
do
    if [ ! -e $LOCK ]
    then
        touch $LOCK
        locked=1
        break
    fi
    sleep 1
    logger -t cloud "edithosts: sleep 1 second wait for the redundant router lock"
done

if [ $locked -eq 0 ]
then
    logger -t cloud "edithosts: fail to get the redundant router lock"
    logger -t cloud "edithosts: keepalived should able to handle the dnsmasq restart"
    exit
fi
fi

# make dnsmasq re-read files
pid=$(pidof dnsmasq)
if [ "$pid" != "" ]
then
  service dnsmasq restart
else
  if [ $no_redundant -eq 1 ]
  then
      wait_for_dnsmasq
  else
      logger -t cloud "edithosts: skip wait dnsmasq due to redundant virtual router"
  fi
fi

ret=$?
if [ $locked -eq 1 ]
then
	rm $LOCK
fi

exit $ret