#!/bin/bash

# check_snmp_disksize
# Description : Check the disk size of Windows server and Unix server
# Version : 1.9
# Author : Yoann LAMY
# Licence : GPLv2

# Commands
CMD_BASENAME="/usr/bin/basename"
CMD_SNMPGET="/usr/bin/snmpget"
CMD_SNMPWALK="/usr/bin/snmpwalk"
CMD_BC="/usr/bin/bc"
CMD_AWK="/usr/bin/awk"
CMD_GREP="/usr/bin/grep"
CMD_EXPR="/usr/bin/expr"

# Script name
SCRIPTNAME=`$CMD_BASENAME $0`

# Version
VERSION="1.9"

# Plugin return codes
STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3

# 'hrStorageDescr', HOST-RESOURCES-MIB
OID_DESC=".1.3.6.1.2.1.25.2.3.1.3"

# 'hrStorageAllocationUnits', HOST-RESOURCES-MIB
OID_UNIT=".1.3.6.1.2.1.25.2.3.1.4"

# 'hrStorageSize', HOST-RESOURCES-MIB
OID_TOTAL=".1.3.6.1.2.1.25.2.3.1.5"

# 'hrStorageUsed', HOST-RESOURCES-MIB
OID_USED=".1.3.6.1.2.1.25.2.3.1.6"

# Default variables
DESCRIPTION="Unknown"
STATE=$STATE_UNKNOWN
CODE=0
DISK_LABEL=""

# Default options
COMMUNITY="public"
HOSTNAME="127.0.0.1"
DISK=""
WARNING=0
CRITICAL=0

# Option processing
print_usage() {
  echo "Usage: ./check_snmp_disksize -H 127.0.0.1 -C public -d C: -w 80 -c 90"
  echo "  $SCRIPTNAME -H ADDRESS"
  echo "  $SCRIPTNAME -C STRING"
  echo "  $SCRIPTNAME -d STRING"
  echo "  $SCRIPTNAME -w INTEGER"
  echo "  $SCRIPTNAME -c INTEGER"
  echo "  $SCRIPTNAME -h"
  echo "  $SCRIPTNAME -V"
}

print_version() {
  echo $SCRIPTNAME version $VERSION
  echo ""
  echo "This nagios plugins comes with ABSOLUTELY NO WARRANTY."
  echo "You may redistribute copies of the plugins under the terms of the GNU General Public License v2."
}

print_help() {
  print_version
  echo ""
  print_usage
  echo ""
  echo "Check the disk size of Windows server and Unix server"
  echo ""
  echo "-H ADDRESS"
  echo "   Name or IP address of host (default: 127.0.0.1)"
  echo "-C STRING"
  echo "   Community name for the host's SNMP agent (default: public)"
  echo "-d STRING"
  echo "   Drive letter (C:) or mount point (/home)"
  echo "-w INTEGER"
  echo "   Warning level for size in percent (default: 0)"
  echo "-c INTEGER"
  echo "   Critical level for size in percent (default: 0)"
  echo "-h"
  echo "   Print this help screen"
  echo "-V"
  echo "   Print version and license information"
  echo ""
  echo ""
  echo "This plugin uses the 'snmpget' command and the 'snmpwalk' command included with the NET-SNMP package."
  echo "This plugin support performance data output."
  echo "If the percentage of the warning and critical levels are set 0, then the script returns a OK state."
}

while getopts H:C:d:w:c:hV OPT
do
  case $OPT in
    H) HOSTNAME="$OPTARG" ;;
    C) COMMUNITY="$OPTARG" ;;
    d) DISK="$OPTARG" ;;
    w) WARNING=$OPTARG ;;
    c) CRITICAL=$OPTARG ;;
    h)
      print_help
      exit $STATE_UNKNOWN
      ;;
    V)
      print_version
      exit $STATE_UNKNOWN
      ;;
   esac
done

# Plugin processing
if [  ${DISK: 0:1} != "/" ]; then
  if [  ${DISK: -1} != ":" ]; then
    DISK="${DISK}:"
  fi
fi

size_convert() {
  if [ $VALUE -ge 1099511627776 ]; then
    VALUE=`echo "scale=2 ; ( ( ( $VALUE / 1024 ) / 1024 ) / 1024 ) / 1024" | $CMD_BC`
    VALUE="$VALUE TB"
  elif [ $VALUE -ge 1073741824 ]; then
    VALUE=`echo "scale=2 ; ( ( $VALUE / 1024 ) / 1024 ) / 1024" | $CMD_BC`
    VALUE="$VALUE GB"
  elif [ $VALUE -ge 1048576 ]; then
    VALUE=`echo "scale=2 ; ( $VALUE / 1024 ) / 1024" | $CMD_BC`
    VALUE="$VALUE MB"
  else
    VALUE=`echo "scale=2 ; $VALUE / 1024" | $CMD_BC`
    VALUE="$VALUE Bytes"
  fi
}

size_fix() {
  if [  ${VALUE: 0:1} = "-" ]; then
    VALUE=`$CMD_EXPR 4294967294 - \( 0 - $VALUE \)`
  fi
}

DISK_DESC=`$CMD_SNMPWALK -t 2 -r 2 -v 1 -c $COMMUNITY $HOSTNAME "$OID_DESC" | $CMD_GREP -w "$DISK"`

if [ -n "$DISK_DESC" ]; then
  DISK_ID=`echo $DISK_DESC | $CMD_AWK '{print $1}' | $CMD_AWK -F "." '{print $NF}'`
  if [  ${DISK: 0:1} != "/" ]; then
    DISK_LABEL=`echo $DISK_DESC | $CMD_AWK '{ print $5 }' | $CMD_AWK -F ':' '{ print $2 }'`
  fi

  DISK_UNIT=`$CMD_SNMPGET -t 2 -r 2 -v 1 -c $COMMUNITY -OvqU $HOSTNAME "${OID_UNIT}.${DISK_ID}"`
  DISK_TOTAL=`$CMD_SNMPGET -t 2 -r 2 -v 1 -c $COMMUNITY -OvqU $HOSTNAME "${OID_TOTAL}.${DISK_ID}"`
  DISK_USED=`$CMD_SNMPGET -t 2 -r 2 -v 1 -c $COMMUNITY -OvqU $HOSTNAME "${OID_USED}.${DISK_ID}"`

  if [ $DISK_TOTAL != 0 ]; then
    VALUE=$DISK_TOTAL
    size_fix
    DISK_TOTAL=$VALUE

    VALUE=$DISK_USED
    size_fix
    DISK_USED=$VALUE

    DISK_TOTAL=`$CMD_EXPR $DISK_TOTAL \* \( $DISK_UNIT \)`
    DISK_USED=`$CMD_EXPR $DISK_USED \* \( $DISK_UNIT \)`
    PERFDATA_WARNING=0
    PERFDATA_CRITICAL=0

    if [ $WARNING != 0 ] || [ $CRITICAL != 0 ]; then
      DISK_USED_POURCENT=`$CMD_EXPR \( $DISK_USED \* 100 \) / $DISK_TOTAL`
      PERFDATA_WARNING=`$CMD_EXPR \( $DISK_TOTAL \* $WARNING \) / 100`
      PERFDATA_CRITICAL=`$CMD_EXPR \( $DISK_TOTAL \* $CRITICAL \) / 100`

      if [ $DISK_USED_POURCENT -gt $CRITICAL ] && [ $CRITICAL != 0 ]; then
        STATE=$STATE_CRITICAL
      elif [ $DISK_USED_POURCENT -gt $WARNING ] && [ $WARNING != 0 ]; then
        STATE=$STATE_WARNING
      else
        STATE=$STATE_OK
      fi
    else
      STATE=$STATE_OK
    fi

    VALUE=$DISK_TOTAL
    size_convert
    DISK_TOTAL_FORMAT=$VALUE

    VALUE=$DISK_USED
    size_convert
    DISK_USED_FORMAT=$VALUE

    DESCRIPTION="Disk/partition usage '$DISK' $DISK_LABEL : $DISK_USED_FORMAT used for a total of $DISK_TOTAL_FORMAT (${DISK_USED_POURCENT}%) | total=${DISK_TOTAL}B;$PERFDATA_WARNING;$PERFDATA_CRITICAL;0 used=${DISK_USED}B;0;0;0"
  fi
fi

echo $DESCRIPTION
exit $STATE