#!/bin/sh
#
# Copyright (C) 2015 Rudolf Cejka
# License: BSD 2-Clause; see file LICENSE-FOSS
#
# Bacula interface to tape libraries and autoloaders for FreeBSD
# (by Rudolf Cejka <cejkar@fit.vutbr.cz>, v1.2, 2012/11/14)
#
#
# If you set in your Device resource
#   Changer Command = "path-to-this-script/chio-changer %c %o %S %a %d"
# you will have the following input to this script:
#   chio-changer "changer-device" "command" "slot" "tape-device" "drive-index"
#                       $1           $2       $3         $4            $5
# for example (on a FreeBSD system):
#   chio-changer /dev/ch0 load 1 /dev/nsa0 0
#
# If you change the script, take care to return either the chio exit
# code or a 0. If the script exits with a non-zero exit code, Bacula
# will assume the request failed.
#

PROGNAME=`basename $0`

# Uncomment the following line, if you want to log debug output.
#DEBUG=/var/run/bacula/${PROGNAME}.log

# Uncomment the following line, if you need to eject a tape before moving
# it from the drive.
#OFFLINE=yes

# Uncomment one or more of the following lines, if you need to wait for
# some time (in seconds) after unloading, loading or transferring a tape.
#OFFLINE_SLEEP=10
#LOAD_SLEEP=10
#MOVE_SLEEP=10

# Uncomment the following line, if you do not have a changer with volume
# reader.
#FAKE_BARCODES=/usr/local/etc/bacula-barcodes

usage()
{
  cat <<EOF
Usage: ${PROGNAME} <changer-device> <cmd> [slot] [tape-device] [drive-index]

Commands (<cmd>):
  unload          Unload a tape into the slot from where it was loaded
  load <slot>     Load a tape from the slot <slot> (1-based)
  transfer <slot> <slotdst> Transfer a tape from the slot <slot> to
                  the slot <slotdst> (1-based)
  list            List full storage slots
  listall         List all storage slots and drives with source information
  loaded          Give slot from where the tape was loaded (0 = empty drive)
  slots           Give number of available slots

Example:
  ${PROGNAME} /dev/ch0 load 1        Load a tape from the slot 1

EOF
  exit 1
}

# Default settings
CHANGER=/dev/ch0
TAPE=/dev/nsa0
DRIVE=0

CHIO=/bin/chio
MT=/usr/bin/mt

if [ -n "${DEBUG}" ]; then
  MSG=$0
  for PAR; do MSG="${MSG} \"${PAR}\""; done
  echo `date +"%Y/%m/%d %H:%M:%S"` ${MSG} >> ${DEBUG}
fi

if [ -n "$1" ]; then
  CHANGER=$1;
fi
COMMAND=$2
SLOT=$3
SLOTDST=$4
if [ -n "$4" ]; then
  TAPE=$4
fi
if [ -n "$5" ]; then
  DRIVE=$5
fi

case ${COMMAND} in
unload)
  if [ "${OFFLINE}" = yes ]; then
    ${MT} -f ${TAPE} offline
    if [ $? = 0 -a -n "${OFFLINE_SLEEP}" ]; then
      sleep ${OFFLINE_SLEEP}
    fi
  fi
  if [ -z "${SLOT}" ]; then
    ${CHIO} -f ${CHANGER} return drive ${DRIVE}
  else
    ${CHIO} -f ${CHANGER} move drive ${DRIVE} slot $((${SLOT} - 1))
  fi
  if [ $? -ne 0 ]; then
    # In case of an error, try to unload the cartridge to the first free slot
    FREE=`${CHIO} -f ${CHANGER} status slot | \
      sed -ne '/FULL/d;s/^slot *\([0-9]*\):.*/\1/p' | \
      awk 'BEGIN { n = 0 } { n = $1 + 1; exit } END { print n }'`
    if [ ${FREE} -gt 0 ]; then
      ${CHIO} -f ${CHANGER} move drive ${DRIVE} slot $((${FREE} - 1))
    else
      exit 1
    fi
  fi
  ;;
load)
  if [ -z "${SLOT}" ]; then
    usage
  fi
  ${CHIO} -f ${CHANGER} move slot $((${SLOT} - 1)) drive ${DRIVE}
  if [ $? -ne 0 ]; then
    exit 1
  fi
  if [ -n "${LOAD_SLEEP}" ]; then
    sleep ${LOAD_SLEEP}
  fi
  ;;
transfer)
  if [ -z "${SLOT}" -o -z "${SLOTDST}" ]; then
    usage
  fi
  ${CHIO} -f ${CHANGER} move slot $((${SLOT} - 1)) slot $((${SLOTDST} - 1))
  if [ $? -ne 0 ]; then
    exit 1
  fi
  if [ -n "${MOVE_SLEEP}" ]; then
    sleep ${MOVE_SLEEP}
  fi
  ;;
list)
  if [ -z "${FAKE_BARCODES}" ]; then
    ${CHIO} -f ${CHANGER} status -v slot | \
      sed -ne 's/^slot *\([0-9]*\):.*FULL.*voltag.*<\([^:]*\):.*/\1:\2/p' | \
      awk -F: '{ print $1 + 1 ":" $2 }'
  else
    if [ -f "${FAKE_BARCODES}" ]; then
      grep -v -e "^#" -e "^$" < ${FAKE_BARCODES}
    else
      echo "${PROGNAME}: Barcode file ${FAKE_BARCODES} is missing"
      exit 1
    fi
  fi
  ;;
listall)
  if [ -z "${FAKE_BARCODES}" ]; then
    ${CHIO} -f ${CHANGER} status -vS | \
      sed -ne '
      s/^slot *\([0-9]*\):.*ENAB.*FULL.*voltag.*<\([^:]*\):.*/I:\1:F:\2/p;t
      s/^slot *\([0-9]*\):.*FULL.*voltag.*<\([^:]*\):.*/S:\1:F:\2/p;t
      s/^drive *\([0-9]*\):.*FULL.*voltag.*<\([^:]*\):.*source.*<[^0-9]*\([0-9]*\)>.*/D:\1:F:\3:\2/p;t
      s/^slot *\([0-9]*\):.*ENAB.*voltag.*<\([^:]*\):.*/I:\1:E/p;t
      s/^slot *\([0-9]*\):.*voltag.*<\([^:]*\):.*/S:\1:E/p;t
      s/^drive *\([0-9]*\):.*voltag.*<\([^:]*\):.*/D:\1:E/p' | \
      awk -F: '{ for (n = 1; n <= NF; n++) printf "%s%s",
      (n == ($1 == "D" ? 4 : 2)) ? ($n == "" ? 0 : $n + 1) : $n,
      (n == NF) ? "\n" : ":" }'
  else
    if [ -f "${FAKE_BARCODES}" ]; then
      grep -v -e "^#" -e "^$" < ${FAKE_BARCODES} | \
        awk -F: '{ print "S:" $1 (match($2, "^ *$") ? ":E" : ":F:" $2) }'
    else
      echo "${PROGNAME}: Barcode file ${FAKE_BARCODES} is missing"
      exit 1
    fi
  fi
  ;;
loaded)
  # If a tape is loaded, but the source slot is unknown (for example,
  # after library reboot), try to report the first free slot
  FREE=`${CHIO} -f ${CHANGER} status slot | \
    sed -ne '/FULL/d;s/^slot *\([0-9]*\):.*/\1/p' | \
    awk 'BEGIN { n = 0 } { n = $1 + 1; exit } END { print n }'`
  ${CHIO} -f ${CHANGER} status -S drive | \
    sed -ne 's/^drive *'${DRIVE}':.*FULL.*source.*<[^0-9]*\([0-9]*\)>.*/\1/p' \
    | awk 'BEGIN { n = 0 } { n = ($1 == "") ? '${FREE}' : $1 + 1 } \
    END { print n }'
  ;;
slots)
  ${CHIO} -f ${CHANGER} status | grep -c "^slot "
  ;;
*)
  usage
  ;;
esac
