#!/bin/bash
#
# Copyright Security Onion Solutions LLC and/or licensed to Security Onion Solutions LLC under one
# or more contributor license agreements. Licensed under the Elastic License 2.0 as shown at 
# https://securityonion.net/license; you may not use this file except in compliance with the
# Elastic License 2.0.

. /usr/sbin/so-common

RECENT_LOG_LINES=200
EXCLUDE_STARTUP_ERRORS=N
EXCLUDE_FALSE_POSITIVE_ERRORS=N
EXCLUDE_KNOWN_ERRORS=N

while [[ $# -gt 0 ]]; do
    case $1 in
        --exclude-connection-errors)
            EXCLUDE_STARTUP_ERRORS=Y
            ;;
        --exclude-false-positives)
            EXCLUDE_FALSE_POSITIVE_ERRORS=Y
            ;;
        --exclude-known-errors)
            EXCLUDE_KNOWN_ERRORS=Y
            ;;
        --unknown)
            EXCLUDE_STARTUP_ERRORS=Y
            EXCLUDE_FALSE_POSITIVE_ERRORS=Y
            EXCLUDE_KNOWN_ERRORS=Y
            ;;
        --recent-log-lines)
            shift
            RECENT_LOG_LINES=$1
            ;;
        *)
            echo "Usage: $0 [options]"
            echo ""
            echo "where options are:"
            echo "  --recent-log-lines N            looks at the most recent N log lines per file or container; defaults to 200"
            echo "  --exclude-connection-errors     exclude errors caused by a recent server or container restart"
            echo "  --exclude-false-positives       exclude logs that are known false positives"
            echo "  --exclude-known-errors          exclude errors that are known and non-critical issues"
            echo "  --unknown                       exclude everything mentioned above; only show unknown errors"
            echo ""
            echo "A non-zero return value indicates errors were found"
            exit 1
            ;;
    esac
    shift
done

echo "Security Onion Log Check - $(date)"
echo "-------------------------------------------"
echo ""
echo "- RECENT_LOG_LINES:                $RECENT_LOG_LINES"
echo "- EXCLUDE_STARTUP_ERRORS:          $EXCLUDE_STARTUP_ERRORS"
echo "- EXCLUDE_FALSE_POSITIVE_ERRORS:   $EXCLUDE_FALSE_POSITIVE_ERRORS"
echo "- EXCLUDE_KNOWN_ERRORS:            $EXCLUDE_KNOWN_ERRORS"
echo ""

function status() {
    header "$1"
}

function exclude_container() {
    name=$1

    exclude_id=$(docker ps | grep "$name" | awk '{print $1}')
    if [[ -n "$exclude_id" ]]; then
        CONTAINER_IDS=$(echo $CONTAINER_IDS | sed -e "s/$exclude_id//g")
        return $?
    fi
    return $?
}

function exclude_log() {
    name=$1

    cat /tmp/log_check_files | grep -v $name > /tmp/log_check_files.new
    mv /tmp/log_check_files.new /tmp/log_check_files
}

function check_for_errors() {
    if cat /tmp/log_check | grep -i error | grep -vEi "$EXCLUDED_ERRORS"; then
        RESULT=1
    fi
}

EXCLUDED_ERRORS="__LOG_CHECK_PLACEHOLDER_EXCLUSION__"

if [[ $EXCLUDE_STARTUP_ERRORS == 'Y' ]]; then
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|database is locked"           # server not yet ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|econnreset"                   # server not yet ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|unreachable"                  # server not yet ready (logstash waiting on elastic)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|shutdown process"             # server not yet ready (logstash waiting on elastic)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|contain valid certificates"   # server not yet ready (logstash waiting on elastic)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|failedaction"                 # server not yet ready (logstash waiting on elastic)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|block in start_workers"       # server not yet ready (logstash waiting on elastic)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|block in buffer_initialize"   # server not yet ready (logstash waiting on elastic)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|no route to host"             # server not yet ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|not running"                  # server not yet ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|unavailable"                  # server not yet ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|request.py"                   # server not yet ready (python stack output)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|httperror"                    # server not yet ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|servfail"                     # server not yet ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|connect"                      # server not yet ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|missing shards"               # server not yet ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|failed to send metrics"       # server not yet ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|broken pipe"                  # server not yet ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|status: 502"                  # server not yet ready (nginx waiting on upstream)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|timeout exceeded"             # server not yet ready (telegraf waiting on elasticsearch)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|influxsize kbytes"            # server not yet ready (telegraf waiting on influx)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|expected field at"            # server not yet ready (telegraf waiting on health data)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|connection timed out"         # server not yet ready (telegraf plugin unable to connect)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|command timed out"            # server not yet ready (telegraf plugin waiting for script to finish)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|cached the public key"        # server not yet ready (salt minion waiting on key acceptance)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|no ingest nodes"              # server not yet ready (logstash waiting on elastic)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|failed to poll"               # server not yet ready (sensoroni waiting on soc)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|minions returned with non"    # server not yet ready (salt waiting on minions)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|so_long_term"                 # server not yet ready (influxdb not yet setup)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|search_phase_execution_exception" # server not yet ready (elastalert running searches before ES is ready)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|timeout retrieving docker"    # Telegraf unable to reach Docker engine, rare
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|timeout retrieving container" # Telegraf unable to reach Docker engine, rare
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|error while communicating"    # Elasticsearch MS -> HN "sensor" temporarily unavailable
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|tls handshake error"          # Docker registry container when new node comes onlines
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|Unable to get license information" # Logstash trying to contact ES before it's ready
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|process already finished"     # Telegraf script finished just as the auto kill timeout kicked in
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|No shard available"           # Typical error when making a query before ES has finished loading all indices
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|responded with status-code 503" # telegraf getting 503 from ES during startup
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|process_cluster_event_timeout_exception" # logstash waiting for elasticsearch to start
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|not configured for GeoIP"     # SO does not bundle the maxminddb with Zeek
fi

if [[ $EXCLUDE_FALSE_POSITIVE_ERRORS == 'Y' ]]; then
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|elastalert_status_error"      # false positive
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|elastalert_error"             # false positive
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|error: '0'"                   # false positive
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|errors_index"                 # false positive
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|noerror"                      # false positive
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|outofmemoryerror"             # false positive (elastic command line)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|adding component template"    # false positive (elastic security)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|adding index template"        # false positive (elastic security)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|fs_errors"                    # false positive (suricata stats)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|error-template"               # false positive (elastic templates)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|deprecated"                   # false positive (playbook)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|windows"                      # false positive (playbook)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|could cause errors"           # false positive (playbook)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|_error.yml"                   # false positive (playbook)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|id.orig_h"                    # false positive (zeek test data)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|emerging-all.rules"           # false positive (error in rulename)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|invalid query input"          # false positive (Invalid user input in hunt query)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|example"                      # false positive (example test data)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|status 200"                   # false positive (request successful, contained error string in content)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|app_layer.error"              # false positive (suricata 7) in stats.log e.g. app_layer.error.imap.parser | Total | 0
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|is not an ip string literal"  # false positive (Open Canary logging out blank IP addresses)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|syncing rule"                 # false positive (rule sync log line includes rule name which can contain 'error') 
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|request_unauthorized"         # false positive (login failures to Hydra result in an 'error' log) 
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|adding index lifecycle policy" # false positive (elasticsearch policy names contain 'error') 
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|adding ingest pipeline"       # false positive (elasticsearch ingest pipeline names contain 'error') 
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|updating index template"      # false positive (elasticsearch index or template names contain 'error') 
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|updating component template"  # false positive (elasticsearch index or template names contain 'error') 
fi

if [[ $EXCLUDE_KNOWN_ERRORS == 'Y' ]]; then
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|eof"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|raise"                        # redis/python generic stack line, rely on other lines for actual error
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|fail\\(error\\)"              # redis/python generic stack line, rely on other lines for actual error
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|urlerror"                     # idstools connection timeout
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|timeouterror"                 # idstools connection timeout
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|_ml"                          # Elastic ML errors 
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|context canceled"             # elastic agent during shutdown
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|geoip databases update"       # airgap can't update GeoIP DB
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|filenotfounderror"            # bug in 2.4.10 filecheck salt state caused duplicate cronjobs
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|salt-minion-check"            # bug in early 2.4 place Jinja script in non-jinja salt dir causing cron output errors
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|monitoring.metrics"           # known issue with elastic agent casting the field incorrectly if an integer value shows up before a float
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|repodownload.conf"            # known issue with reposync on pre-2.4.20 
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|missing versions record"      # stenographer corrupt index
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|soc.field."                   # known ingest type collisions issue with earlier versions of SO
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|error parsing signature"      # Malformed Suricata rule, from upstream provider
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|sticky buffer has no matches" # Non-critical Suricata error
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|Unable to determine destination index stats"  # Elastic transform temporary error
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|cannot join on an empty table" # InfluxDB flux query, import nodes
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|exhausting result iterator"   # InfluxDB flux query mismatched table results (temporary data issue)
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|failed to finish run"         # InfluxDB rare error, self-recoverable
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|Unable to gather disk name"   # InfluxDB known error, can't read disks because the container doesn't have them mounted
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|iteration"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|communication packets"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|use of closed"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|bookkeeper"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|noindices"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|failed to start transient scope"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|so-user.lock exists"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|systemd-run"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|retcode: 1"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|telemetry-task"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|redisqueue"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|fleet_detail_query"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|num errors=0"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|provisioning/alerting"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|provisioning/notifiers"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|provisoning/plugins"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|active-responses.log"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|scanentropy"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|integration policy"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|blob unknown"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|token required"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|zeekcaptureloss"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|unable to create detection"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|error installing new prebuilt rules"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|parent.error"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|req.LocalMeta.host.ip"        # known issue in GH
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|sendmail"                     # zeek
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|stats.log"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|Unknown column"               # Elastalert errors from running EQL queries
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|parsing_exception"            # Elastalert EQL parsing issue. Temp.
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|context deadline exceeded"
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|Error running query:"         # Specific issues with detection rules
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|detect-parse"                 # Suricata encountering a malformed rule
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|integrity check failed"       # Detections: Exclude false positive due to automated testing
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|syncErrors"                   # Detections: Not an actual error
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|Initialized license manager"  # SOC log: before fields.status was changed to fields.licenseStatus
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|from NIC checksum offloading" # zeek reporter.log
    EXCLUDED_ERRORS="$EXCLUDED_ERRORS|marked for removal"           # docker container getting recycled
fi

RESULT=0

# Check Security Onion container stdout/stderr logs
CONTAINER_IDS=$(docker ps -q)
exclude_container so-kibana   # kibana error logs are too verbose with large varieties of errors most of which are temporary
exclude_container so-idstools # ignore due to known issues and noisy logging
exclude_container so-playbook # Playbook is removed as of 2.4.70, disregard output in stopped containers
exclude_container so-mysql    # MySQL is removed as of 2.4.70, disregard output in stopped containers
exclude_container so-soctopus # Soctopus is removed as of 2.4.70, disregard output in stopped containers

for container_id in $CONTAINER_IDS; do
    container_name=$(docker ps --format json | jq ". | select(.ID==\"$container_id\")|.Names")
    status "Checking container $container_name"
    docker logs -n $RECENT_LOG_LINES $container_id > /tmp/log_check 2>&1
    check_for_errors
done

# Check Security Onion related log files
find /opt/so/log/ /nsm -name \*.log > /tmp/log_check_files
if [[ -f /var/log/cron ]]; then
    echo "/var/log/cron" >> /tmp/log_check_files
fi
exclude_log "kibana.log"   # kibana error logs are too verbose with large varieties of errors most of which are temporary
exclude_log "spool"        # disregard zeek analyze logs as this is data specific
exclude_log "import"       # disregard imported test data the contains error strings
exclude_log "update.log"   # ignore playbook updates due to several known issues
exclude_log "cron-cluster-delete.log" # ignore since Curator has been removed
exclude_log "cron-close.log" # ignore since Curator has been removed
exclude_log "curator.log"  # ignore since Curator has been removed
exclude_log "playbook.log" # Playbook is removed as of 2.4.70, logs may still be on disk
exclude_log "mysqld.log"   # MySQL is removed as of 2.4.70, logs may still be on disk
exclude_log "soctopus.log" # Soctopus is removed as of 2.4.70, logs may still be on disk
exclude_log "agentstatus.log" # ignore this log since it tracks agents in error state
exclude_log "detections_runtime-status_yara.log" # temporarily ignore this log until Detections is more stable
exclude_log "/nsm/kafka/data/" # ignore Kafka data directory from log check.

# Include Zeek reporter.log to detect errors after running known good pcap(s) through sensor
echo "/nsm/zeek/spool/logger/reporter.log" >> /tmp/log_check_files

for log_file in $(cat /tmp/log_check_files); do
    status "Checking log file $log_file"
    tail -n $RECENT_LOG_LINES $log_file > /tmp/log_check
    check_for_errors
done

# Cleanup temp files
rm -f /tmp/log_check_files
rm -f /tmp/log_check

if [[ $RESULT -eq 0 ]]; then
    echo -e "\nResult: No errors found"
else
    echo -e "\nResult: One or more errors found"
fi

exit $RESULT