#!/bin/sh
# AUTHOR -|
# 	 Matt Wells - phanoko@gmail.com
# NAME -|
#	 check_VciscoSNMP
# SYNOPSIS -|
# 	 nagios check for cisco
# DESCRIPTION -|
#	 Since Cisco lacks continuity when setting up their OID strings I wrote this check.  
# 	 This check is written only for SNMP v3 but could be modified easily.
#	 We didn't want to add hundreds of checks for every possible OID as it would simply clutter our Nagios XI setup.  
# 	 This would cause multiple issues going forward with maintaining the server.
#
# 	 For this reason I outsourced some of the check data to flat files; as they are easier to maintain and give us 
#	 the benefit of an “out of sight, out of mind” setup.
#
#	 The check expects a directory called mibcisco, one directory level below the libexec directory.  
#	 Within this directory it reads in control files. These files are your IP address or hostname, depending on how 
#	 you setup your devices in Nagios.
#
#	 With in the file it expects to find two environment variables called
#        AUTHP = Auth password
#	 PRIVP = Priv password
#	 COMMUNITY = Community/username
#
#	 These are the first three lines of the file.  It's important that the line count is correct as it's a control 
#	 in the service checks themselves.
#
#	 Starting on line 5 the configurations start and use pipes as a separator.
#	 DESCRIPTION|OID|EXPECTED-VALUE
#	 See below for a complete example of the file
#		--------------------------
#		AUTHP='123abc'
#		PRIVP='abc123'
#		COMMUNITY='public'
#		##############
#		#|GigabitEthernet3/5: Trunk to switch.example.com:fa0/24|IF-MIB::ifOperStatus.2|up(1)
#		-------------------------
#	 When entering your description, MIB and code please remember to use a #| to start the line. If not Nagios will attempt
#	 execute the line while reading it in.
#	 Once you've put in your control files add the check into Nagios.  The script expects to have $ARG1$.
#	 This first argument is the line number of the check you want to perform. 
#	 So in the example file above our service would be created and called something generic like 
#	 “Cisco SNMP Check 1” and have $ARG1$ = 1
#
#        This would pull the 5th line of the file above and check that OID against it's expected value. 
#        The description will always be returned in the results.
#        If you were checking 4 switches with 7 service checks like below.
#        “Cisco SNMP Check 1” and have $ARG1$ = 1
#        “Cisco SNMP Check 2” and have $ARG1$ = 2
#        “Cisco SNMP Check 3” and have $ARG1$ = 3
#        “Cisco SNMP Check 4” and have $ARG1$ = 4
#        “Cisco SNMP Check 5” and have $ARG1$ = 5
#        “Cisco SNMP Check 6” and have $ARG1$ = 6
#        “Cisco SNMP Check 7” and have $ARG1$ = 7
#        Later if you added another switch with 10 checks you would simply extend these checks associating them as 
#        needed with devices.
#        Keeping it generic like this creates a cleaner configuration within Nagios and in our deployment an easier way 
#        to manage systems.
# REVISIONS -|
#        1.0
#        1.1 - Left out argument to capture line number and had to make a change to the flat file system.  
#            - While reading it in some lines were giving an error and Nagios was dropping out.
#        1.2 - gggrrr.. Couldn't leave this alone.  I made the count add 4 so Check 1 would have an $ARG1$ = 1
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin

STATE_OK=0
STATE_CRITICAL=2
#
MIBMAPS="/usr/local/nagios/mibscisco/"
NDIR="/usr/local/nagios/libexec/"
DEVICE="${MIBMAPS}$2"
COUNT=$(($3+4))
. ${DEVICE}
DESCRIPTION="`awk -F\| 'NR=='${COUNT}'{print $2}' ${DEVICE}`"
MIBB="`awk -F\| 'NR=='${COUNT}'{print $3}' ${DEVICE}`"
CODE="`awk -F\| 'NR=='${COUNT}'{print $4}' ${DEVICE}`"

#SNMP Check itself, This could of course be modified for SNMPv2.
SNMPCHECK=`${NDIR}check_snmp -H $2 -o ${MIBB} -C ${COMMUNITY} -P 3 --seclevel=authPriv --secname=nagios --authproto=SHA --authpasswd=${AUTHP} --privpasswd=${PRIVP}| awk '{print $4}'`

# Return Code Logic
if [ "${CODE}" == "${SNMPCHECK}" ]; then
        echo "${DESCRIPTION}"
        exit ${STATE_OK}
else
        echo "${DESCRIPTION}"
        exit ${STATE_CRITICAL}
fi