class.ilErrorHandling.php

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<?php

declare(strict_types=1);

use Whoops\Run;
use Whoops\RunInterface;
use Whoops\Handler\PrettyPageHandler;
use Whoops\Handler\CallbackHandler;
use Whoops\Exception\Inspector;
use Whoops\Handler\HandlerInterface;

class ilErrorHandling
{
    private const SENSTIVE_PARAMETER_NAMES = [
        'password',
        'passwd',
        'passwd_retype',
        'current_password',
        'usr_password',
        'usr_password_retype',
        'new_password',
        'new_password_retype',
    ];

    protected ?RunInterface $whoops;

    protected string $message;
    protected bool $DEBUG_ENV;

    public int $FATAL = 1;

    public int $WARNING = 2;

    public int $MESSAGE = 3;

    protected static bool $whoops_handlers_registered = false;

    public function __construct()
    {
        $this->DEBUG_ENV = true;
        $this->FATAL = 1;
        $this->WARNING = 2;
        $this->MESSAGE = 3;

        $this->initWhoopsHandlers();

        // somehow we need to get rid of the whoops error handler
        restore_error_handler();
        set_error_handler([$this, 'handlePreWhoops']);
    }

    protected function initWhoopsHandlers(): void
    {
        if (self::$whoops_handlers_registered) {
            // Only register whoops error handlers once.
            return;
        }
        $ilRuntime = $this->getIlRuntime();
        $this->whoops = $this->getWhoops();
        $this->whoops->pushHandler(new ilDelegatingHandler($this, self::SENSTIVE_PARAMETER_NAMES));
        if ($ilRuntime->shouldLogErrors()) {
            $this->whoops->pushHandler($this->loggingHandler());
        }
        $this->whoops->register();
        self::$whoops_handlers_registered = true;
    }

    public function getHandler(): HandlerInterface
    {
        if (ilContext::getType() === ilContext::CONTEXT_SOAP &&
            strcasecmp($_SERVER['REQUEST_METHOD'] ?? '', 'post') === 0) {
            return new ilSoapExceptionHandler();
        }

        // TODO: There might be more specific execution contexts (WebDAV, REST, etc.) that need specific error handling.

        if ($this->isDevmodeActive()) {
            return $this->devmodeHandler();
        }

        return $this->defaultHandler();
    }

    public function raiseError(
        string $message,
        ?int $code
    ): void {
        $backtrace = debug_backtrace();
        if (isset($backtrace[0], $backtrace[0]['object'])) {
            unset($backtrace[0]['object']);
        }

        // see bug 18499 (some calls to raiseError do not pass a code, which leads to security issues, if these calls
        // are done due to permission checks)
        $this->errorHandler($message, $code ?? $this->WARNING, $backtrace);
    }

    private function errorHandler(string $message, int $code, array $backtrace): void
    {
        global $log;

        $session_failure = ilSession::get('failure');
        if ($session_failure && strpos($message, 'Cannot find this block') !== 0) {
            $m = 'Fatal Error: Called raise error two times.<br>' .
                'First error: ' . $session_failure . '<br>' .
                'Last Error:' . $message;
            $log->write($m);
            ilSession::clear('failure');
            die($m);
        }

        if (strpos($message, 'Cannot find this block') === 0) {
            if (defined('DEVMODE') && DEVMODE) {
                echo '<b>DEVMODE</b><br><br>';
                echo '<b>Template Block not found.</b><br>';
                echo 'You used a template block in your code that is not available.<br>';
                echo 'Native Messge: <b>' . $message . '</b><br>';
                echo 'Backtrace:<br>';
                foreach ($backtrace as $b) {
                    if ($b['function'] === 'setCurrentBlock' &&
                        basename($b['file']) !== 'class.ilTemplate.php') {
                        echo '<b>';
                    }
                    echo 'File: ' . $b['file'] . ', ';
                    echo 'Line: ' . $b['line'] . ', ';
                    echo $b['function'] . '()<br>';
                    if ($b['function'] === 'setCurrentBlock' &&
                        basename($b['file']) !== 'class.ilTemplate.php') {
                        echo '</b>';
                    }
                }
                exit;
            }
            return;
        }

        if ($log instanceof ilLogger) {
            $log->write($message);
        }
        if ($code === $this->FATAL) {
            trigger_error(stripslashes($message), E_USER_ERROR);
            exit();
        }

        if ($code === $this->WARNING) {
            if (!$this->DEBUG_ENV) {
                $message = 'Under Construction';
            }

            ilSession::set('failure', $message);

            if (!defined('ILIAS_MODULE')) {
                ilUtil::redirect('error.php');
            } else {
                ilUtil::redirect('../error.php');
            }
        }
        $updir = '';
        if ($code === $this->MESSAGE) {
            ilSession::set('failure', $message);
            // save post vars to session in case of error
            $_SESSION['error_post_vars'] = $_POST;

            if (empty($_SESSION['referer'])) {
                $dirname = dirname($_SERVER['PHP_SELF']);
                $ilurl = parse_url(ilUtil::_getHttpPath());

                $subdir = '';
                if (is_array($ilurl) && array_key_exists('path', $ilurl) && $ilurl['path'] !== '') {
                    $subdir = substr(strstr($dirname, (string) $ilurl['path']), strlen((string) $ilurl['path']));
                    $updir = '';
                }
                if ($subdir) {
                    $num_subdirs = substr_count($subdir, '/');

                    for ($i = 1; $i <= $num_subdirs; $i++) {
                        $updir .= '../';
                    }
                }
                ilUtil::redirect($updir . 'index.php');
            }
            ilUtil::redirect($_SESSION['referer']);
        }
    }

    public function getMessage(): string
    {
        return $this->message;
    }

    public function setMessage(string $a_message): void
    {
        $this->message = $a_message;
    }

    public function appendMessage(string $a_message): void
    {
        if ($this->getMessage()) {
            $this->message .= '<br /> ';
        }
        $this->message .= $a_message;
    }

    protected function getIlRuntime(): ilRuntime
    {
        return ilRuntime::getInstance();
    }

    protected function getWhoops(): RunInterface
    {
        return new Run();
    }

    protected function isDevmodeActive(): bool
    {
        return defined('DEVMODE') && (int) DEVMODE === 1;
    }

    protected function defaultHandler(): HandlerInterface
    {
        return new CallbackHandler(function ($exception, Inspector $inspector, Run $run) {
            global $DIC;

            $session_id = substr(session_id(), 0, 5);
            $random = new ilRandom();
            $err_num = $random->int(1, 9999);
            $file_name = $session_id . '_' . $err_num;

            $logger = ilLoggingErrorSettings::getInstance();
            if (!empty($logger->folder())) {
                $lwriter = new ilLoggingErrorFileStorage($inspector, $logger->folder(), $file_name);
                $lwriter = $lwriter->withExclusionList(self::SENSTIVE_PARAMETER_NAMES);
                $lwriter->write();
            }

            //Use $lng if defined or fallback to english
            if ($DIC->isDependencyAvailable('language')) {
                $DIC->language()->loadLanguageModule('logging');
                $message = sprintf($DIC->language()->txt('log_error_message'), $file_name);

                if ($logger->mail()) {
                    $message .= ' ' . sprintf(
                        $DIC->language()->txt('log_error_message_send_mail'),
                        $logger->mail(),
                        $file_name,
                        $logger->mail()
                    );
                }
            } else {
                $message = 'Sorry, an error occured. A logfile has been created which can be identified via the code "' . $file_name . '"';

                if ($logger->mail()) {
                    $message .= ' ' . 'Please send a mail to <a href="mailto:' . $logger->mail() . '?subject=code: ' . $file_name . '">' . $logger->mail() . '</a>';
                }
            }
            if ($DIC->isDependencyAvailable('ui') && isset($DIC['tpl']) && $DIC->isDependencyAvailable('ctrl')) {
                $DIC->ui()->mainTemplate()->setOnScreenMessage('failure', $message, true);
                $DIC->ctrl()->redirectToURL('error.php');
            } else {
                ilSession::set('failure', $message);
                header('Location: error.php');
                exit;
            }
        });
    }

    protected function devmodeHandler(): HandlerInterface
    {
        global $ilLog;

        switch (ERROR_HANDLER) {
            case 'TESTING':
                return (new ilTestingHandler())->withExclusionList(self::SENSTIVE_PARAMETER_NAMES);

            case 'PLAIN_TEXT':
                return (new ilPlainTextHandler())->withExclusionList(self::SENSTIVE_PARAMETER_NAMES);

            case 'PRETTY_PAGE':
                // fallthrough
            default:
                if ((!defined('ERROR_HANDLER') || ERROR_HANDLER !== 'PRETTY_PAGE') && $ilLog) {
                    $ilLog->write(
                        "Unknown or undefined error handler '" . ERROR_HANDLER . "'. " .
                        'Falling back to PrettyPageHandler.'
                    );
                }

                $prettyPageHandler = new PrettyPageHandler();

                $this->addEditorSupport($prettyPageHandler);

                foreach (self::SENSTIVE_PARAMETER_NAMES as $param) {
                    $prettyPageHandler->blacklist('_POST', $param);
                }

                return $prettyPageHandler;
        }
    }

    protected function addEditorSupport(PrettyPageHandler $handler): void
    {
        $editorUrl = defined('ERROR_EDITOR_URL') ? ERROR_EDITOR_URL : '';
        if (!is_string($editorUrl) || $editorUrl === '') {
            return;
        }

        $pathTranslationConfig = defined('ERROR_EDITOR_PATH_TRANSLATIONS') ? ERROR_EDITOR_PATH_TRANSLATIONS : '';

        $pathTranslations = $this->parseEditorPathTranslation($pathTranslationConfig);

        $handler->setEditor(function ($file, $line) use ($editorUrl, $pathTranslations) {
            $this->applyEditorPathTranslations($file, $pathTranslations);

            return str_ireplace(
                ['[FILE]', '[LINE]'],
                [$file, $line],
                $editorUrl
            );
        });
    }

    protected function applyEditorPathTranslations(string &$file, array $pathTranslations): void
    {
        foreach ($pathTranslations as $from => $to) {
            $file = preg_replace('@' . $from . '@', $to, $file);
        }
    }

    protected function parseEditorPathTranslation(string $pathTranslationConfig): array
    {
        $pathTranslations = [];

        $mappings = explode('|', $pathTranslationConfig);
        foreach ($mappings as $mapping) {
            $parts = explode(',', $mapping);
            if (count($parts) === 2) {
                $pathTranslations[trim($parts[0])] = trim($parts[1]);
            }
        }

        return $pathTranslations;
    }

    protected function loggingHandler(): HandlerInterface
    {
        return new CallbackHandler(function ($exception, Inspector $inspector, Run $run) {
            global $ilLog;

            if (is_object($ilLog)) {
                $message = $exception->getMessage() . ' in ' . $exception->getFile() . ':' . $exception->getLine();
                $message .= $exception->getTraceAsString();

                $previous = $exception->getPrevious();
                while ($previous) {
                    $message .= "\n\nCaused by\n" . sprintf(
                        '%s: %s in file %s on line %d',
                        get_class($previous),
                        $previous->getMessage(),
                        $previous->getFile(),
                        $previous->getLine()
                    );
                    $previous = $previous->getPrevious();
                }

                $ilLog->error($exception->getCode() . ' ' . $message);
            }

            // Send to system logger
            error_log($exception->getMessage());
        });
    }

    public function handlePreWhoops(int $level, string $message, string $file, int $line): bool
    {
        global $ilLog;

        if ($level & error_reporting()) {
            if (!$this->isDevmodeActive()) {
                // log E_USER_NOTICE, E_STRICT, E_DEPRECATED, E_USER_DEPRECATED only
                if ($level >= E_USER_NOTICE) {
                    if ($ilLog) {
                        $severity = Whoops\Util\Misc::translateErrorCode($level);
                        $ilLog->write("\n\n" . $severity . ' - ' . $message . "\n" . $file . ' - line ' . $line . "\n");
                    }
                    return true;
                }
            }

            if ($this->whoops instanceof RunInterface) {
                return $this->whoops->handleError($level, $message, $file, $line);
            }
        }

        return true;
    }
}