#!/bin/bash

myUsername="Guest"

ST_OK=0
ST_WR=1
ST_CR=2
ST_UK=3

if [ -z "$1" ]; then
	echo "check_smbsize written by Charles Shortridge (cshortridge at gmail.com)" 
	echo "Usage: check_smbsize -H Host -S Share [-U username] [-P password] [-W Warning] [-C Critical]"
	echo "	-H <IP or Hostname>"
	echo "	Specify the SMB Host to connect to"
	echo "	-S <Sharename>"
	echo "	Specify the SMB Share"
	echo "Optional:"
	echo "	-U"
	echo "	The Username to use"
	echo "	-P"
	echo "	The Password to use"
	echo "	-W <warning %>"
	echo "	The available % free to signal a warning"
	echo "	-C <critical %>"
	echo "	The available % free to signal a critical"
	echo ""	
	exit
fi

while test -n "$1"; do
	case "$1" in
	-H)
	myHost=$2
	shift
	;;
	-S)
	myShare=$2
	shift
	;;
	-U)
	myUsername=$2
	shift
	;;
	-P)
	myPassword=$2
	shift
	;;
	-W)
	myWarn=$2
	shift
	;;
	-C)
	myCrit=$2
	shift
	;;
	*)
	echo "Error: Unknown argument $1"
	exit
	;;
	esac
shift	
done

if [ -z "$myHost" ]; then
	echo "Hostname is required"
	exit
fi

if [ -z "$myShare" ]; then
	echo "Share is required"
	exit
fi

if [ -z "$myPassword" ]; then
	myUsername="$myUsername -N"
fi

blocksline=$(smbclient -U $myUsername -c du //$myHost/$myShare $myPassword | grep blocks) 
numblocks=$(echo $blocksline | cut -d' ' -f1)
blocksize=$(echo $blocksline | cut -d' ' -f5 | tr -d .)
freeblocks=$(echo $blocksline | cut -d' ' -f6)
if [ -z $numblocks ]; then
	echo "Error: Check Username/Password"
	exit
fi

totalM=$(echo $numblocks*$blocksize/1024/1024|bc)
freeM=$(echo $freeblocks*$blocksize/1024/1024|bc)
freeper=$(echo "scale=2;$freeM/$totalM*100"|bc)

if [ -n "$myCrit" ]; then
	dowarn=$(echo "$myCrit >= $freeper"|bc)
	if [ $dowarn -eq "1" ]; then
		echo "Critical: Total: ${totalM}MB - Free: ${freeM}MB ($freeper%) (Critical Threshold: ${myCrit}%)"
		exit $ST_CR
	fi
fi

if [ -n "$myWarn" ]; then
	dowarn=$(echo "$myWarn >= $freeper"|bc)
	if [ $dowarn -eq "1" ]; then
		echo "Warning: Total: ${totalM}MB - Free: ${freeM}MB ($freeper%) (Warning Threshold: ${myWarn}%)"
		exit $ST_WR
	fi
fi

echo "OK: Total: ${totalM}MB - Free: ${freeM}MB ($freeper%)"
exit $ST_OK