#!/bin/sh
#
# Bacula interface to virtual autoloader using disk storage
#
#  Written by Kern Sibbald
#
#   Bacula(R) - The Network Backup Solution
#
#   Copyright (C) 2000-2022 Kern Sibbald
#
#   The original author of Bacula is Kern Sibbald, with contributions
#   from many others, a complete list can be found in the file AUTHORS.
#
#   You may use this file and others of this release according to the
#   license defined in the LICENSE file, which includes the Affero General
#   Public License, v3.0 ("AGPLv3") and some additional permissions and
#   terms pursuant to its AGPLv3 Section 7.
#
#   This notice must be preserved when any source code is 
#   conveyed and/or propagated.
#
#   Bacula(R) is a registered trademark of Kern Sibbald.
#  If you set in your Device resource
#
#  Changer Command = "path-to-this-script/disk-changer %c %o %S %a %d"
#    you will have the following input to this script:
#
#  So Bacula will always call with all the following arguments, even though
#    in come cases, not all are used. Note, the Volume name is not always
#    included.
#
#  disk-changer "changer-device" "command" "slot" "archive-device" "drive-index" "volume"
#		    $1		    $2	     $3        $4		$5	   $6
#
# By default the autochanger has 10 Volumes and 1 Drive.
#
# Note: For this script to work, you *must" specify
#    Device Type = File 
# in each of the Devices associated with your AutoChanger resource.
#
# changer-device is the name of a file that overrides the default
#   volumes and drives.  It may have:
#	 maxslot=n   where n is one based (default 10)
#	 maxdrive=m  where m is zero based (default 1 -- i.e. 2 drives)
#  
#   This code can also simulate barcodes. You simply put
#   a list of the slots and barcodes in the "base" directory/barcodes.
#   See below for the base directory definition.  Example of a 
#   barcodes file:
#      /var/bacula/barcodes
#      1:Vol001
#      2:Vol002
#      ...
# 
# archive-device is the name of the base directory where you want the
#  Volumes stored appended with /drive0 for the first drive; /drive1
#  for the second drive, ... For example, you might use
#  /var/bacula/drive0  Note: you must not have a trailing slash, and
#  the string (e.g. /drive0) must be unique, and it must not match
#  any other part of the directory name. These restrictions could be
#  easily removed by any clever script jockey.
#
#  Full example: disk-changer /var/bacula/conf load 1 /var/bacula/drive0 0 TestVol001
#
# The Volumes will be created with names slot1, slot2, slot3, ... maxslot in the
#  base directory. In the above example the base directory is /var/bacula.
#  However, as with tapes, their Bacula Volume names will be stored inside the
#  Volume label. In addition to the Volumes (e.g. /var/bacula/slot1, 
#  /var/bacula/slot3, ...) this script will create a /var/bacula/loadedn
#  file to keep track of what Slot is loaded. You should not change this file.
#
# Modified 8 June 2010 to accept Volume names from the calling program as arg 6.
#  In this case, rather than storing the data in slotn, it is stored in the
#  Volume name.  Note: for this to work, Volume names may not include spaces.
#

wd=/var/lib/bacula

#
# log whats done
#
# to turn on logging, uncomment the following line
#touch $wd/disk-changer.log
#
dbgfile="$wd/disk-changer.log"
debug() {
    if test -f $dbgfile; then
	echo "`date +\"%Y%m%d-%H:%M:%S\"` $*" >> $dbgfile
    fi
}


#
# Create a temporary file
#
make_temp_file() {
  TMPFILE=`mktemp -t mtx.XXXXXXXXXX`
  if test x${TMPFILE} = x; then
     TMPFILE="$wd/disk-changer.$$"
     if test -f ${TMPFILE}; then
	echo "Temp file security problem on: ${TMPFILE}"
	exit 1
     fi
  fi
}

# check parameter count on commandline
#
check_parm_count() {
    pCount=$1
    pCountNeed=$2
    if test $pCount -lt $pCountNeed; then
	echo "usage: disk-changer ctl-device command [slot archive-device drive-index]"
	echo "	Insufficient number of arguments arguments given."
	if test $pCount -lt 2; then
	    echo "  Mimimum usage is first two arguments ..."
	else
	    echo "  Command expected $pCountNeed arguments"
	fi
	exit 1
    fi
}

#
# Strip off the final name in order to get the Directory ($dir)
#  that we are dealing with.
#
get_dir() {
   bn=`basename $device`
   dir=`echo "$device" | sed -e s%/$bn%%g`
   if [ ! -d $dir ]; then
      echo "ERROR: Autochanger directory \"$dir\" does not exist."
      echo "	   You must create it."
      exit 1
   fi
}

#
# Get the Volume name from the call line, or directly from
#  the volslotn information.
#
get_vol() {
   havevol=0
   debug "vol=$volume"
   if test "x$volume" != x && test "x$volume" != "x*NONE*" ; then
      debug "touching $dir/$volume"
      touch $dir/$volume
      echo "$volume" >$dir/volslot${slot}
      havevol=1
   elif [ -f $dir/volslot${slot} ]; then
      volume=`cat $dir/volslot${slot}`
      havevol=1
   fi
}


# Setup arguments
ctl=$1
cmd="$2"
slot=$3
device=$4
drive=$5
volume=$6

# set defaults
maxdrive=1
maxslot=10

# Pull in conf file
if [ -f $ctl ]; then 
   . $ctl
fi


# Check for special cases where only 2 arguments are needed, 
#  all others are a minimum of 5
#
case $2 in
    list|listall)
	check_parm_count $# 2
	;;
    slots)
	check_parm_count $# 2
	;;
    transfer)
	check_parm_count $# 4
	if [ $slot -gt $maxslot ]; then
	   echo "Slot ($slot) out of range (1-$maxslot)"
	   debug "Error: Slot ($slot) out of range (1-$maxslot)"
	   exit 1
	fi
	;;
    *)
	check_parm_count $# 5
	if [ $drive -gt $maxdrive ]; then
	   echo "Drive ($drive) out of range (0-$maxdrive)"
	   debug "Error: Drive ($drive) out of range (0-$maxdrive)"
	   exit 1
	fi
	if [ $slot -gt $maxslot ]; then
	   echo "Slot ($slot) out of range (1-$maxslot)"
	   debug "Error: Slot ($slot) out of range (1-$maxslot)"
	   exit 1
	fi
	;;
esac


debug "Parms: $ctl $cmd $slot $device $drive $volume $havevol"

case $cmd in 
   unload)
      debug "Doing disk -f $ctl unload $slot $device $drive $volume"
      get_dir
      if [ -f $dir/loaded${drive} ]; then
	 ld=`cat $dir/loaded${drive}`
      else 
	 echo "Storage Element $slot is Already Full"
	 debug "Unload error: $dir/loaded${drive} is already unloaded"
	 exit 1
      fi
      if [ $slot -eq $ld ]; then
	 echo "0" >$dir/loaded${drive}
	 unlink $device 2>/dev/null >/dev/null
	 unlink ${device}.add 2>/dev/null >/dev/null
	 rm -f ${device} ${device}.add
      else
	 echo "Storage Element $slot is Already Full"
	 debug "Unload error: $dir/loaded${drive} slot=$ld is already unloaded"
	 exit 1
      fi
      ;;

   load)
      debug "Doing disk $ctl load $slot $device $drive $volume"
      get_dir
      i=0
      # Check if slot already in a drive
      while [ $i -le $maxdrive ]; do
	 if [ -f $dir/loaded${i} ]; then
	    ld=`cat $dir/loaded${i}`
	 else	 
	    ld=0
	 fi
	 if [ $ld -eq $slot ]; then
	    echo "Drive ${i} Full (Storage element ${ld} loaded)"
	    debug "Load error: Cannot load Slot=${ld} in drive=$drive. Already in drive=${i}"
	    exit 1
	 fi
	 i=`expr $i + 1`
      done
      # Check if we have a Volume name
      get_vol
      if [ $havevol -eq 0 ]; then
	 # check if slot exists
	 if [ ! -f $dir/slot${slot} ] ; then
	    echo "source Element Address $slot is Empty"
	    debug "Load error: source Element Address $slot is Empty"
	    exit 1
	 fi
      fi
      if [ -f $dir/loaded${drive} ]; then
	 ld=`cat $dir/loaded${drive}`
      else
	 ld=0
      fi
      if [ $ld -ne 0 ]; then
	 echo "Drive ${drive} Full (Storage element ${ld} loaded)"
	 echo "Load error: Drive ${drive} Full (Storage element ${ld} loaded)"
	 exit 1
      fi
      echo "0" >$dir/loaded${drive}
      unlink $device 2>/dev/null >/dev/null
      unlink ${device}.add 2>/dev/null >/dev/null
      rm -f ${device} ${device}.add
      if [ $havevol -ne 0 ]; then
	 ln -s $dir/$volume $device
	 ln -s $dir/${volume}.add ${device}.add
	 rtn=$?
      else
	 ln -s $dir/slot${slot} $device
	 ln -s $dir/slot${slot}.add ${device}.add
	 rtn=$?
      fi
      if [ $rtn -eq 0 ]; then
	 echo $slot >$dir/loaded${drive}
      fi
      exit $rtn
      ;;

   list) 
      debug "Doing disk -f $ctl -- to list volumes"
      get_dir 
      if [ -f $dir/barcodes ]; then
	 cat $dir/barcodes
      else
	 i=1
	 while [ $i -le $maxslot ]; do
	    slot=$i
	    volume=
	    get_vol
	    if [ $havevol -eq 0 ]; then
	       echo "$i:"
	    else
	       echo "$i:$volume"
	    fi
	    i=`expr $i + 1`
	 done
      fi
      exit 0
      ;;

   listall) 
      # ***FIXME*** must add new Volume stuff
      make_temp_file
      debug "Doing disk -f $ctl -- to list volumes"
      get_dir 
      if [ ! -f $dir/barcodes ]; then
	  exit 0
      fi

      # we print drive content seen by autochanger
      # and we also remove loaded media from the barcode list
      i=0
      while [ $i -le $maxdrive ]; do
	 if [ -f $dir/loaded${i} ]; then
	     ld=`cat $dir/loaded${i}`
	     v=`awk -F: "/^$ld:/"' { print $2 }' $dir/barcodes`
	     echo "D:$i:F:$ld:$v"
	     echo "^$ld:" >> $TMPFILE
	 fi
	 i=`expr $i + 1`
      done

      # Empty slots are not in barcodes file
      # When we detect a gap, we print missing rows as empty
      # At the end, we fill the gap between the last entry and maxslot
      grep -v -f $TMPFILE $dir/barcodes | sort -n | \
      perl -ne 'BEGIN { $cur=1 } 
       if (/(\d+):(.+)?/) {
	 if ($cur == $1) { 
	   print "S:$1:F:$2\n" 
	 } else { 
	   while ($cur < $1) {
	      print "S:$cur:E\n";
	      $cur++;
	   }
	 }
	 $cur++;
       } 
       END { while ($cur < '"$maxslot"') { print "S:$cur:E\n"; $cur++; } } '

      rm -f $TMPFILE
      exit 0
      ;;
   transfer)
      #  ***FIXME*** must add new Volume stuff
      get_dir
      make_temp_file
      slotdest=$device
      if [ -f $dir/slot{$slotdest} ]; then
	 echo "destination Element Address $slot is Full"
	 exit 1
      fi
      if [ ! -f $dir/slot${slot} ] ; then
	 echo "source Element Address $slot is Empty"
	 exit 1
      fi

      echo "Transfering $slot to $slotdest"
      mv $dir/slot${slot} $dir/slot{$slotdest}
      mv $dir/slot${slot}.add $dir/slot{$slotdest}.add

      if [ -f $dir/barcodes ]; then
	 sed "s/^$slot:/$slotdest:/" >	$TMPFILE
	 sort -n $TMPFILE > $dir/barcodes
      fi
      exit 0
      ;;
   loaded)
      debug "Doing disk -f $ctl $drive -- to find what is loaded"
      get_dir
      if [ -f $dir/loaded${drive} ]; then
	 a=`cat $dir/loaded${drive}`
      else
	 a="0"
      fi
      debug "Loaded: drive=$drive is $a"
      echo $a
      exit
      ;;

   slots)
      debug "Doing disk -f $ctl -- to get count of slots"
      echo $maxslot
      ;;
esac
