nagios/plugins/check_rdns

   1 #!/bin/sh
   2
   3 # Copyright (c) 2013 Stefan Huber <shuber@sthu.org>
   4 #
   5 # Permission is hereby granted, free of charge, to any person
   6 # obtaining a copy of this software and associated documentation
   7 # files (the "Software"), to deal in the Software without
   8 # restriction, including without limitation the rights to use,
   9 # copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 # copies of the Software, and to permit persons to whom the
  11 # Software is furnished to do so, subject to the following
  12 # conditions:
  13 #
  14 # The above copyright notice and this permission notice shall be
  15 # included in all copies or substantial portions of the Software.
  16 #
  17 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18 # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  19 # OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  20 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  21 # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  22 # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  24 # OTHER DEALINGS IN THE SOFTWARE.
  25
  26 . $(dirname $0)/utils.sh
  27
  28
  29 PROGNAME=$(basename $0)
  30 REVISION="0.1"
  31
  32 usage() {
  33
  34     cat <<EOF
  35 check_rdns v$REVISION
  36 Copyright (c) 2013 Stefan Huber <shuber@sthu.org>
  37
  38 Usage: $PROGNAME -H ip-address [OPTIONS]
  39
  40 Arguments:
  41     -H, --address IP-address    The ip-addres on which reverse-DNS is performed.
  42
  43 Options:
  44     -h, --help                  Print this text.
  45     -a, --expect=HOST           The expected result.
  46     -s, --server=HOST           The DNS server to contact.
  47     -t, --timeout=SEC           Seconds before lookup times out. (Default: 10)
  48     -w, --warning=MSEC          Return warning if lookup time exceeds value.
  49     -c, --critical=MSEC         Return critical if lookup time exceeds value.
  50     -V, --version               Print version info.
  51 EOF
  52 }
  53
  54
  55 TEMP=`getopt -o "H:a:c:hs:t:w:V" --long "help,address:,expect:,critical:,server:,timeout:,warning:,version" -n "$PROGNAME" -- "$@"`
  56 eval set - "$TEMP"
  57
  58 ADDRESS=
  59 EXPECT=
  60 SERVER=
  61 TIMEOUT=10
  62 WARNING=
  63 CRITICAL=
  64
  65 while true; do
  66     case "$1" in
  67         -h | --help )
  68             usage
  69             exit $STATE_OK ;;
  70         -V | --version )
  71             echo "$PROGNAME v$REVISION"
  72             exit $STATE_OK ;;
  73         -H | --address )
  74             ADDRESS="$2"; shift 2 ;;
  75         -a | --expect )
  76             EXPECT="$2"; shift 2 ;;
  77         -s | --server )
  78             SERVER="$2"; shift 2 ;;
  79         -t | --timeout )
  80             TIMEOUT="$2"; shift 2 ;;
  81         -w | --warning )
  82             WARNING="$2"; shift 2 ;;
  83         -c | --critical )
  84             CRITICAL="$2"; shift 2 ;;
  85         -- )
  86             shift
  87             break ;;
  88         * )
  89             break ;;
  90     esac
  91 done
  92
  93 if [ -z "$ADDRESS" ]; then
  94     echo "Error: No address given."
  95     usage
  96     exit $STATE_CRITICAL
  97 fi
  98
  99 DIGOPTS="+time=$TIMEOUT +noquestion +noauthority -t PTR"
 100 [ -z "$SERVER" ] || DIGOPTS="@$SERVER $DIGOPTS"
 101
 102 RESULT=$(dig $DIGOPTS -x "$ADDRESS"):
 103 DIGSTATUS=$?
 104
 105 if [ $DIGSTATUS != "0" ]; then
 106     echo "DNS failed: dig exit code $DIGSTATUS |"
 107     exit $STATE_CRITICAL
 108 fi
 109
 110 # Get the actual result
 111 HOST=$(echo "$RESULT" | grep -m 1 -o "[[:space:]]IN[[:space:]]*PTR[[:space:]].*\.$" | awk '{ print $3 }' )
 112 if [ -z "$HOST" ]; then
 113     echo "DNS failed: reverse DNS gave no answer. |"
 114     exit $STATE_CRITICAL
 115 fi
 116
 117
 118 # Get the query time in msec
 119 QUERYTIME=$(echo "$RESULT" | grep -m 1 "Query time:" | cut -d ":" -f 2 | awk '{ print $1 }')
 120
 121
 122 MATCHED=
 123 if [ -n "$EXPECT" ]; then
 124     if [ "$EXPECT" != "$HOST" ]; then
 125         echo "DNS critical - query result \"$HOST\" != \"$EXPECT\", query time: $QUERYTIME msec |"
 126         exit $STATE_CRITICAL
 127     else
 128         MATCHED=" (match ok)"
 129     fi
 130 fi
 131
 132 if [ -n "$CRITICAL" ] && [ "$QUERYTIME" -gt "$CRITICAL" ]; then
 133     echo "DNS critical - query time $QUERYTIME msec too large ($CRITICAL msec), query result: \"$HOST\"$MATCHED |"
 134     exit $STATE_CRITICAL
 135 fi
 136
 137 if [ -n "$WARNING" ] && [ "$QUERYTIME" -gt "$WARNING" ]; then
 138     echo "DNS warning - query time $QUERYTIME msec too large ($WARNING msec), query result: \"$HOST\"$MATCHED |"
 139     exit $STATE_WARNING
 140 fi
 141
 142 echo "DNS OK - query time $QUERYTIME msec, query result: \"$HOST\"$MATCHED |"
 143 exit $STATE_OK
 144