#!/bin/bash
#
# pcapsipdump file rotation
# By Nathan Thomas
# 12/05/2014
#

### VARS ###
# Location of the pcapsipdump config file
CONF_FILE='/etc/default/pcapsipdump';

# Keep the spool folder clean - Delete all folders (except those in the ignored directories array)
# yes - Keep the spool folder free from any directories not in the ignore list
# no - Don't worry about any other random folders in the spool directory
# NOTE: Beware that any folders with names similar to YYYYMMDD format and are integers may possibly
# get deleted from the spool folder if an exception is not placed specifically in the ignore whitelist
PURGE_ALL='no';

# An array of any subdirectories in the spool folder we want to keep no matter what
# If PURGE_ALL='yes' then any subdirectories you want to keep in the spool folder need to be added to this whitelist
# If PURGE_ALL='no' then any subdirectories not in date format will be ignored and you can
# still use this variable to specify any specific folders in date format that you do wish to keep
IGNORE_DIRS=('tools' 'somedir' 'someotherdir');

### CODE ###
# If file doesn't exist quit
if [ ! -e "${CONF_FILE}" ] ; then
	 echo "The pcapsipdump config file does not exist at '${CONF_FILE}', aborting...";
        exit 1;
fi

# Simple var check
case "${PURGE_ALL}" in
	"yes"|"no")
	;;
	*)
	echo "The PURGE_ALL variable can only be 'yes' or 'no'.";
	exit 1;
	;;
esac

# Get retention period and spool directory variables
RETENTION=$(cat "${CONF_FILE}" | grep "RETENTION=" | awk -F '=' '{ print $2 }');
SPOOLDIR=$(cat "${CONF_FILE}" | grep "SPOOLDIR=" | awk -F '=' '{ print $2 }');
# If retention period isn't numeric quit
if [ ! "${RETENTION}" -eq "${RETENTION}" ] > /dev/null 2>&1; then
	echo "The retention period in the config file was not numeric, aborting..."; 
	exit 1;
fi
# If spool directory doesn't exist quit
if [ ! -d "${SPOOLDIR}" ] > /dev/null 2>&1; then
	echo "The pcapsipdump spool directory does not exist at '${SPOOLDIR}', aborting...";
	exit 1;
fi

# Get subdirectory string
SUBDIRS=$(basename -a $(ls -d "${SPOOLDIR}"/*)) > /dev/null 2>&1;
# Set internal field seperator to split on carriage return
IFS=$'\n';
# Create array of subdirectory names
SUBDIRS=($(echo "${SUBDIRS}" | sed ':a;N;$!ba;s/\r\n/ /g')) > /dev/null 2>&1;

# Loop through subdirectory names
for DIRS in "${SUBDIRS[@]}" ; do
	i=0
	# Loop through the ignored directories array and test for matches
	for ITEMS in "${IGNORE_DIRS[@]}" ; do
		# if string doesn't match increase counter
		if [ ! "${DIRS}" == "${ITEMS}" ] ; then
			((i++));
			# if counter reaches total number of elements
			if [ "${i}" -eq "${#IGNORE_DIRS[@]}" ] ; then
	                        # Push into new array
        	                NEWSUBDIRS=("${NEWSUBDIRS[@]}" "${DIRS}");
                	        i=0;  # reset counter
			fi
		else
			# strings match, do nothing (bitchslap)
			break;
		fi
	done
done

# Convert YYYYMMDD to Unix Time
# params: $1=date
function YMD2U () {
	local VAR="${1}";
	if [ "${VAR}" -eq "${VAR}" ] > /dev/null 2>&1; then  # if is numeric
		# check var length
		if [ ! "${#VAR}" -eq 8 ] ; then  # Not a full 8 digits
			return 1;  # Date not in YYYYMMDD format...probably a subdirectory
		fi
		# Additional crude/laughable date checks
		local YEAR="${VAR:0:4}";
		local MONTH="${VAR:4:2}";
		local DAY="${VAR:6:2}";
		if [ "${YEAR}" -lt 0000 -o "${YEAR}" -gt 3000 ] ; then
			return 1;  # Invalid year
		fi
		if [ "${MONTH}" -lt 1 -o  "${MONTH}" -gt 12 ] ; then
	                return 1;  # Invalid month
                fi
		if [ "${DAY}" -lt 1 -o  "${DAY}" -gt 31 ] ; then
	                return 1;  # Invalid day
                fi
		# lastly check validity with date command
		local RETVAR="$(date -d ${VAR} +%s)";
		echo "${RETVAR}" | grep -q "invalid date";
		if [ ! "$?" -eq 0 ] ; then
			echo "${RETVAR}";
			return 0;
		else
			return 1;  # Date command returned invalid
		fi
	else
		return 1;  # Wasn't numeric
	fi
}

# Convert Unix Time to YYYYMMDD
# params: $1=date
function U2YMD () {
	local VAR="${1}";
        if [ "${VAR}" -eq "${VAR}" ] > /dev/null 2>&1; then  # if is numeric
		# check validity with date command
		local RETVAR="$(date +"%Y%m%d" -d @${VAR})";
		echo "${RETVAR}" | grep -q "invalid date";
                if [ ! "$?" -eq 0 ] ; then
			echo "${RETVAR}";
	                return 0;
                else
                        return 1;  # Date command returned invalid
		fi
	else
		return 1;
        fi
}

# Convert retention period to seconds
RETSEC=$((${RETENTION}*86400));

for DIR in "${NEWSUBDIRS[@]}" ; do
	# Make sure the function runs ok
	YMD2U "${DIR}" > /dev/null 2>&1;
	RETVAL="$?";
	if [ "${RETVAL}" -eq 0 ] ; then
		# if utime of dir <= (current utime - retention period)
		if [ $(YMD2U "${DIR}") -le $(($(date +%s)-${RETSEC})) ] ; then
			rm -rf ${SPOOLDIR}/${DIR} > /dev/null 2>&1;
		fi
        else
		# Function returned 1 and this folder is not numeric or in YYYYMMDD format
		if [ "${PURGE_ALL}" == "yes" ] ; then
			rm -rf ${SPOOLDIR}/${DIR} > /dev/null 2>&1;
		fi
	fi
done