#!/bin/bash
#
# copyleft Whit Blauvelt 17 Sept. 2012
#
# This script sends 5 TCP SYN pings to a host and compares critical and
# warning tresholds against average round trip time (ms). It also reports
# critical on 100% packet loss. The user (e.g. "nagios") must have sudoers
# permission to run hping3. The port should be that used by some service on
# the host.
#
###########################################################################
VERSION="check_hping v0.01"

# edit to match location on system; hping2 should also work
HPING="/usr/sbin/hping3"

usage()
{
cat << EOF

usage: $0 [host] [warning max rtt] [critical max rtt] [port]

This script sends 5 TCP SYN pings to a host and compares critical and
warning tresholds against average round trip time (ms). It also reports
critical on 100% packet loss. The user (e.g. "nagios") must have sudoers
permission to run hping3. The port should be that used by some service on
the host.

EOF
}

RET="0"

if [ ! -n "$1" ]
then
	echo "- Missing [host]"
	RET="1"
fi   

if [ ! -n "$2" ]
then
	echo "- Missing [warning max rtt]"
	RET="1"
fi   

if [ ! -n "$3" ]
then
	echo "- Missing [critical max rtt]"
	RET="1"
fi   

if [ ! -n "$4" ]
then
	echo "- Missing [port]"
	RET="1"
fi   

if [ $RET == "1" ]
then
	usage
	exit 3
fi


PRE=`sudo ${HPING} -q -n -p $4 -c 5 -S $1 2>&1`
AVG=`echo $PRE | awk -F/ '{ print $4 }' | awk 'BEGIN{RS=FS="";OFS=""} $1=$1' | awk -F "." '{ print $1 }'`
PKT=`echo $PRE | awk -F, '{ print $3 }' | awk -F " " '{ print $1 }'`

if [ ! -n "$AVG" ]
then
	if [ $PKT == "100%" ]
	then
		echo "CRITICAL: packet loss $PKT"
	else
		echo "CRITICAL: Error pinging"
	fi
	exit 2
elif [ $AVG -le "$2" ]
then
	SC="OK"
	EX=0
elif [ $AVG -le "$3" ]
then
	SC="WARNING"
	EX=1
else
	SC="CRITICAL"
	EX=2
fi

echo "$SC: Average response time $AVG ms; packet loss $PKT"
exit $EX