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shinken

shinken 1.2.4 on ubuntu desktop 12.10 iv

3 Apr 2013

copied from shinken-monitoring.org

motivation

shinken can be used to monitor dhcp servers easiliy but i wasn’t able to find a script which monitors that nobody accidently enabled another dhcp server which probably will create a lot of trouble.

check_dhcp_server_count script

#! /bin/bash
#
# js@lastlog.de
# 28/03/2013
#
#  This Nagios dhcp server test plugin checks that there are only known
#  active dhcp servers.
#
# dhcping -s 255.255.255.255 -r -v
# Got answer from: 62.8.254.69
# received from 62.8.254.69, expected from 255.255.255.255
# Got answer from: 62.8.254.91
# received from 62.8.254.91, expected from 255.255.255.255
# no answer
#
# chmod u+s /usr/sbin/dhcping
# chmod 0755 check_dhcp_server_count
# chown shinken:shinken check_dhcp_server_count

PROGNAME=`basename $0`
PROGPATH=`echo $0 | sed -e 's,[\\/][^\\/][^\\/]*$,,'`
REVISION="0.0.1"

. $PROGPATH/utils.sh

print_usage() {
  echo "Usage:"
  echo "  $PROGNAME --help"
  echo "  $PROGNAME --test"
  echo "  $PROGNAME --version"
}

print_help() {
  print_revision $PROGNAME $REVISION
  echo ""
  print_usage
  echo ""
  echo "Nagios dhcp server test plugin - prevent multiple dhcp servers"
  echo ""
  echo "--test"
  echo "   Perform the test"
  echo "--help"
  echo "   Print this help screen"
  echo "--version"
  echo "   Print version and license information"
  echo ""
  support
}

# Information options
case "$1" in
--help)
                print_help
    exit $STATE_OK
    ;;
-h)
                print_help
    exit $STATE_OK
    ;;
--version)
                print_revision $PROGNAME $REVISION
    exit $STATE_OK
    ;;
-V)
                print_revision $PROGNAME $REVISION
    exit $STATE_OK
    ;;
--test)
    
    n=$(dhcping -s 255.255.255.255 -r -v 2>&1  | grep received | wc -l)
    case "$n" in
      1)
          echo "STATE_OK - exactly one dhcp server found - $(date)"
          exit $STATE_OK
      ;;
      0)
          echo "STATE_CRITICAL - no dhcp server found - $(date)"
          exit $STATE_CRITICAL
      ;;
      *)
          echo "STATE_CRITICAL - several dhcp servers found! - $(date)"
          exit $STATE_CRITICAL
      ;;
    esac
    ;;
*)
    print_usage
    exit $STATE_UNKNOWN
esac

etc/services/services.cfg

define service{
       use                      generic-service
       service_description      DHCPD_count
       host_name                myserver.example.com
       check_command            check_dhcp_server_count
}

commands.cfg

define command {
    command_name    check_dhcp_server_count
    command_line    $PLUGINSDIR$/check_dhcp_server_count --test
}

security

i don’t like setuid [1] for /usr/sbin/dhcping and /usr/local/shinken/libexec/check_dhcp but i don’t see any other way to implement it.

define command {
    command_name    check_my_dhcp
    command_line    $PLUGINSDIR$/check_dhcp -i eth12 -m 010203040506 -r 192.168.1.1 -s 192.168.1.76 
}

check_dhcp [2] needs also be set: chmod u+s check_dhcp

chmod u+s /usr/local/shinken/libexec/check_dhcp
ls -la /usr/local/shinken/libexec/check_dhcp
-r-sr-xr-x  1 root    root    141246 2013-02-27 10:53 check_dhcp*

and

chmod u+s /usr/sbin/dhcping
ls -la /usr/sbin/dhcping
-rwsr-xr-x 1 root root 15256 2008-11-25 12:25 dhcping*

summary

the script is doing its job well so far. i would like to change some tiny things like being able to:

links