Subversion Repositories vnag

<?php

/*

 * VNag - Nagios Framework for PHP

 * Developed by Daniel Marschall, ViaThinkSoft <www.viathinksoft.com>

 * Licensed under the terms of the Apache 2.0 license

 *

 * Revision 2023-10-13

 */

// QUE: should we allow usernames to have wildcards, regexes or comma separated?

declare(ticks=1);

class LastCheck extends VNag {

        private $argUser = null;

        private $argRegex = null;

        private $argWtmpFiles = null;

        private $argEmptyOk = null;

        private $argIpInfoToken = null;

        private $cache = null;

        private $cacheFile = null;

        private $cacheDirty = false;

        public function __construct() {

                parent::__construct();

                if ($this->is_http_mode()) {

                        // Don't allow the standard arguments via $_REQUEST

                        $this->registerExpectedStandardArguments('');

                } else {

                        $this->registerExpectedStandardArguments('Vhtv');

                }

                $this->addExpectedArgument($this->argUser = new VNagArgument('u', 'user', VNagArgument::VALUE_REQUIRED, 'user', 'The Linux username. If the argument is missing, all users will be checked.', null));

                $this->addExpectedArgument($this->argRegex = new VNagArgument('R', 'regex', VNagArgument::VALUE_REQUIRED, 'regex', 'The regular expression (in PHP: preg_match) which is applied on IP, Hostname, Country, AS number or ISP name. If the regular expression matches, the login will be accepted, otherweise an alert will be triggered. Example: /DE/ismU or /Telekom/ismU', null));

                $this->addExpectedArgument($this->argWtmpFiles = new VNagArgument('f', 'wtmpfile', VNagArgument::VALUE_REQUIRED, 'wtmpfile', 'Filemask of the wtmp file (important if you use logrotate), e.g. \'/var/log/wtmp*\'', '/var/log/wtmp*'));

                $this->addExpectedArgument($this->argEmptyOk = new VNagArgument('e', 'emptyok', VNagArgument::VALUE_FORBIDDEN, null, 'Treat an empty result (e.g. empty wtmp file after rotation) as success; otherwise treat it as status "Unknown"', null));

                $this->addExpectedArgument($this->argIpInfoToken = new VNagArgument(null, 'ipInfoToken', VNagArgument::VALUE_REQUIRED, 'token', 'If you have a token for ipinfo.io, please enter it here. Without token, you can query the service approx 1,000 times per day (which should be enough)', null));

                $this->getHelpManager()->setPluginName('vnag_last');

                $this->getHelpManager()->setVersion('2023-10-13');

                $this->getHelpManager()->setShortDescription('This plugin checks the logs of the tool "LAST" an warns when users have logged in with an unexpected IP/Country/ISP.');

                $this->getHelpManager()->setCopyright('Copyright (C) 2011-$CURYEAR$ Daniel Marschall, ViaThinkSoft.');

                $this->getHelpManager()->setSyntax('$SCRIPTNAME$ [-v] [-e] [-u username] [-R regex] [--ipInfoToken token]');

                $this->getHelpManager()->setFootNotes('If you encounter bugs, please contact ViaThinkSoft at www.viathinksoft.com');

                $this->cacheFile = $this->get_cache_dir().'/'.hash('sha256','LastCheck:last_ip_cache');

                if (!file_exists($this->cacheFile)) @touch($this->cacheFile);

                $this->cache = $this->cacheFile ? json_decode(file_get_contents($this->cacheFile),true) : array();

        }

        public function __destruct() {

                if ($this->cacheFile && $this->cacheDirty) {

                        @file_put_contents($this->cacheFile, json_encode($this->cache));

                }

        }

        private function getCountryAndOrg($ip) {

                if (isset($this->cache[$ip])) return $this->cache[$ip];

                $url = 'https://ipinfo.io/'.urlencode($ip).'/json';

                $token = $this->argIpInfoToken->getValue();

                if ($token) $url .= '?token='.urlencode($token);

                // fwrite(STDERR, "Note: Will query $url\n");

                $cont = $this->url_get_contents($url);

                if ($cont === false) return array();

                if (($data = @json_decode($cont, true)) === false) return array();

                if (isset($data['error'])) return array();

                if (isset($data['bogon']) && ($data['bogon'])) {

                        // Things like 127.0.0.1 do not belong to anyone

                        $res = array();

                } else {

                        $res = array();

                        if (isset($data['hostname'])) $res[] = $data['hostname'];

                        if (isset($data['country'])) $res[] = $data['country'];

                        list($as, $orgName) = explode(' ', $data['org'], 2);

                        $res[] = $as;

                        $res[] = $orgName;

                }

                $this->cache[$ip] = $res;

                $this->cacheDirty = true;

                return $res;

        }

        private function getLastLoginIPs($username) {

                $cont = '';

                $files = glob($this->argWtmpFiles->getValue());

                foreach ($files as $file) {

                        if (trim($username) == '') {

                                $cont .= shell_exec('last -f '.escapeshellarg($file).' -F -w '); // all users

                        } else {

                                $cont .= shell_exec('last -f '.escapeshellarg($file).' -F -w '.escapeshellarg($username));

                        }

                }

                preg_match_all('@^(\S+)\s+(\S+)\s+(\S+)\s+(.+)$@ismU', $cont, $m, PREG_SET_ORDER);

                foreach ($m as $key => &$a) {

                        if (($a[2] === 'system') && ($a[3] === 'boot')) {

                                // reboot   system boot  4.9.0-8-amd64    Fri Oct 12 02:10   still running

                                // reboot   system boot  6.1.0-11-amd64   Fri Sep  8 13:10:27 2023 - Sat Sep  9 17:40:50 2023 (1+04:30)

                                unset($m[$key]);

                        //} else if ($a[2] === 'begins') {

                        } else if (substr($a[1],0,4) === 'wtmp') {

                                // wtmp.1 begins Fri Oct 12 02:10:43 2018   (English)

                                // wtmp beginnt Wed Aug 16 11:43:03 2023    (German)

                                unset($m[$key]);

                        } else {

                                array_shift($a);

                        }

                }

                return $m;

        }

        protected function cbRun() {

                if (!`which which`) {

                        throw new VNagException("Program 'which' is not installed on your system");

                }

                if (!`which last`) {

                        throw new VNagException("Program 'last' (usually included in package smartmontools) is not installed on your system");

                }

                $username = $this->argUser->available() ? $this->argUser->getValue() : '';

                $regex = $this->argRegex->available() ? $this->argRegex->getValue() : null;

                if (($username != '') && function_exists('posix_getpwnam') && !posix_getpwnam($username)) {

                        $this->setStatus(VNag::STATUS_WARNING);

                        $this->addVerboseMessage("WARNING: Currently, there is no Linux user with name '$username'.", VNag::VERBOSITY_SUMMARY);

                }

                $count_total = 0;

                $count_ok = 0;

                $count_warning = 0;

                foreach ($this->getLastLoginIPs($username) as list($username, $pts, $ip, $times)) {

                        // IP ":pts/0:S.0" means that there is a screen session

                        if (strpos($ip,':pts/') === 0) continue;

                        $count_total++;

                        $fields = $this->getCountryAndOrg($ip);

                        $fields[] = $ip;

                        if (is_null($regex)) {

                                // No regex. Just show the logins for information (status stays VNag::STATUS_UNKNOWN)

                                $this->addVerboseMessage("INFO: ".implode(' ',$fields)." @ $username, $pts $times", VNag::VERBOSITY_ADDITIONAL_INFORMATION);

                        } else {

                                $match = false;

                                foreach ($fields as $f) {

                                        if (preg_match($regex, $f, $dummy)) {

                                                $match = true;

                                                break;

                                        }

                                }

                                if ($match) {

                                        $count_ok++;

                                        $this->addVerboseMessage("OK: ".implode(' ',$fields)." @ $username $pts $times", VNag::VERBOSITY_ADDITIONAL_INFORMATION);

                                        $this->setStatus(VNag::STATUS_OK);

                                } else {

                                        $count_warning++;

                                        $this->addVerboseMessage("WARNING: ".implode(' ',$fields)." @ $username $pts $times", VNag::VERBOSITY_SUMMARY);

                                        $this->setStatus(VNag::STATUS_WARNING);

                                }

                        }

                }

                if (is_null($regex)) {

                        $this->setHeadline("Checked $count_total logins (No checks done because argument 'Regex' is missing)");

                } else {

                        if (($count_total == 0) && ($this->argEmptyOk->count() > 0)) {

                                $this->setStatus(VNag::STATUS_OK);

                        }

                        $this->setHeadline("Checked $count_total logins ($count_ok OK, $count_warning Warning)");

                }

        }

}