#!/bin/bash

# Delete Zeek Logs based on defined CRIT_DISK_USAGE value

# Copyright 2014,2015,2016,2017,2018, 2019 Security Onion Solutions, LLC

#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

SENSOR_DIR='/nsm'
CRIT_DISK_USAGE=90
CUR_USAGE=$(df -P $SENSOR_DIR | tail -1 | awk '{print $5}' | tr -d %)
LOG="/opt/so/log/sensor_clean.log"
TODAY=$(date -u "+%Y-%m-%d")

clean() {
	## find the oldest Zeek logs directory
	OLDEST_DIR=$(ls /nsm/zeek/logs/ | grep -v "current" | grep -v "stats" | grep -v "packetloss" | grep -v "zeek_clean" | sort | head -n 1)
	if [ -z "$OLDEST_DIR" -o "$OLDEST_DIR" == ".." -o "$OLDEST_DIR" == "." ]; then
		echo "$(date) - No old Zeek logs available to clean up in /nsm/zeek/logs/" >>$LOG
		#exit 0
	else
		echo "$(date) - Removing directory: /nsm/zeek/logs/$OLDEST_DIR" >>$LOG
		rm -rf /nsm/zeek/logs/"$OLDEST_DIR"
	fi

	## Remarking for now, as we are moving extracted files to /nsm/strelka/processed
	## find oldest files in extracted directory and exclude today
	#OLDEST_EXTRACT=$(find /nsm/zeek/extracted/complete -type f -printf '%T+ %p\n' 2>/dev/null | sort | grep -v $TODAY | head -n 1)
	#if [ -z "$OLDEST_EXTRACT" -o "$OLDEST_EXTRACT" == ".." -o "$OLDEST_EXTRACT" == "." ]
	#then
	#        echo "$(date) - No old extracted files available to clean up in /nsm/zeek/extracted/complete" >> $LOG
	#else
	#        OLDEST_EXTRACT_DATE=`echo $OLDEST_EXTRACT | awk '{print $1}' | cut -d+ -f1`
	#        OLDEST_EXTRACT_FILE=`echo $OLDEST_EXTRACT | awk '{print $2}'`
	#        echo "$(date) - Removing extracted files for $OLDEST_EXTRACT_DATE" >> $LOG
	#        find /nsm/zeek/extracted/complete -type f -printf '%T+ %p\n' | grep $OLDEST_EXTRACT_DATE | awk '{print $2}' |while read FILE
	#        do
	#                echo "$(date) - Removing extracted file: $FILE" >> $LOG
	#                rm -f "$FILE"
	#        done
	#fi

	## Clean up Zeek extracted files processed by Strelka
	STRELKA_FILES='/nsm/strelka/processed'
	OLDEST_STRELKA=$(find $STRELKA_FILES -type f -printf '%T+ %p\n' | sort -n | head -n 1)
	if [ -z "$OLDEST_STRELKA" -o "$OLDEST_STRELKA" == ".." -o "$OLDEST_STRELKA" == "." ]; then
		echo "$(date) - No old files available to clean up in $STRELKA_FILES" >>$LOG
	else
		OLDEST_STRELKA_DATE=$(echo $OLDEST_STRELKA | awk '{print $1}' | cut -d+ -f1)
		OLDEST_STRELKA_FILE=$(echo $OLDEST_STRELKA | awk '{print $2}')
		echo "$(date) - Removing extracted files for $OLDEST_STRELKA_DATE" >>$LOG
		find $STRELKA_FILES -type f -printf '%T+ %p\n' | grep $OLDEST_STRELKA_DATE | awk '{print $2}' | while read FILE; do
			echo "$(date) - Removing file: $FILE" >>$LOG
			rm -f "$FILE"
		done
	fi

	## Clean up Suricata log files
	SURICATA_LOGS='/nsm/suricata'
	OLDEST_SURICATA=$(find $SURICATA_LOGS -type f -printf '%T+ %p\n' | sort -n | head -n 1)
	if [[ -z "$OLDEST_SURICATA" ]] || [[ "$OLDEST_SURICATA" == ".." ]] || [[ "$OLDEST_SURICATA" == "." ]]; then
		echo "$(date) - No old files available to clean up in $SURICATA_LOGS" >>$LOG
	else
		OLDEST_SURICATA_DATE=$(echo $OLDEST_SURICATA | awk '{print $1}' | cut -d+ -f1)
		OLDEST_SURICATA_FILE=$(echo $OLDEST_SURICATA | awk '{print $2}')
		echo "$(date) - Removing logs for $OLDEST_SURICATA_DATE" >>$LOG
		find $SURICATA_LOGS -type f -printf '%T+ %p\n' | grep $OLDEST_SURICATA_DATE | awk '{print $2}' | while read FILE; do
			echo "$(date) - Removing file: $FILE" >>$LOG
			rm -f "$FILE"
		done
	fi

	# Clean Wazuh archives
	# Slightly different code since we have 2 files to remove (.json and .log)
	WAZUH_ARCHIVE='/nsm/wazuh/logs/archives'
	OLDEST_WAZUH=$(find $WAZUH_ARCHIVE -type f ! -name "archives.json" -printf "%T+\t%p\n" | sort -n | awk '{print $1}' | head -n 1)
	# Make sure we don't delete the current files
	find $WAZUH_ARCHIVE -type f ! -name "archives.json" -printf "%T+\t%p\n" | sort -n | awk '{print $2}' | head -n 1 >/tmp/files$$
	if [[ $(wc -l </tmp/files$$) -ge 1 ]]; then
		echo "$(date) - Removing logs for $OLDEST_WAZUH" >>$LOG
		while read -r line; do
			echo "$(date) - Removing file: $line" >>$LOG
			rm "$line"
		done </tmp/files$$
	else
		echo "$(date) - No old files available to clean up in $WAZUH_ARCHIVE" >>$LOG
	fi
	rm /tmp/files$$

	## Clean up extracted pcaps from Steno
	PCAPS='/nsm/pcapout'
	OLDEST_PCAP=$(find $PCAPS -type f -printf '%T+ %p\n' | sort -n | head -n 1)
	if [ -z "$OLDEST_PCAP" -o "$OLDEST_PCAP" == ".." -o "$OLDEST_PCAP" == "." ]; then
		echo "$(date) - No old files available to clean up in $PCAPS" >>$LOG
	else
		OLDEST_PCAP_DATE=$(echo $OLDEST_PCAP | awk '{print $1}' | cut -d+ -f1)
		OLDEST_PCAP_FILE=$(echo $OLDEST_PCAP | awk '{print $2}')
		echo "$(date) - Removing extracted files for $OLDEST_PCAP_DATE" >>$LOG
		find $PCAPS -type f -printf '%T+ %p\n' | grep $OLDEST_PCAP_DATE | awk '{print $2}' | while read FILE; do
			echo "$(date) - Removing file: $FILE" >>$LOG
			rm -f "$FILE"
		done
	fi
}

# Check to see if we are already running
IS_RUNNING=$(ps aux | pgrep -f "so-sensor-clean" | wc -l)
[ "$IS_RUNNING" -gt 3 ] && echo "$(date) - $IS_RUNNING sensor clean script processes running...exiting." >>$LOG && exit 0

if [ "$CUR_USAGE" -gt "$CRIT_DISK_USAGE" ]; then
	while [ "$CUR_USAGE" -gt "$CRIT_DISK_USAGE" ]; do
		clean
		CUR_USAGE=$(df -P $SENSOR_DIR | tail -1 | awk '{print $5}' | tr -d %)
	done
fi