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Diffstat (limited to 'www/wiki/includes/exception/MWExceptionRenderer.php')
| -rw-r--r-- | www/wiki/includes/exception/MWExceptionRenderer.php | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/www/wiki/includes/exception/MWExceptionRenderer.php b/www/wiki/includes/exception/MWExceptionRenderer.php new file mode 100644 index 00000000..5d750365 --- /dev/null +++ b/www/wiki/includes/exception/MWExceptionRenderer.php @@ -0,0 +1,338 @@ +<?php +/** + * 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 2 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * http://www.gnu.org/copyleft/gpl.html + * + * @file + */ + +use Wikimedia\Rdbms\DBConnectionError; +use Wikimedia\Rdbms\DBError; +use Wikimedia\Rdbms\DBReadOnlyError; +use Wikimedia\Rdbms\DBExpectedError; + +/** + * Class to expose exceptions to the client (API bots, users, admins using CLI scripts) + * @since 1.28 + */ +class MWExceptionRenderer { + const AS_RAW = 1; // show as text + const AS_PRETTY = 2; // show as HTML + + /** + * @param Exception|Throwable $e Original exception + * @param int $mode MWExceptionExposer::AS_* constant + * @param Exception|Throwable|null $eNew New exception from attempting to show the first + */ + public static function output( $e, $mode, $eNew = null ) { + global $wgMimeType; + + if ( defined( 'MW_API' ) ) { + // Unhandled API exception, we can't be sure that format printer is alive + self::header( 'MediaWiki-API-Error: internal_api_error_' . get_class( $e ) ); + wfHttpError( 500, 'Internal Server Error', self::getText( $e ) ); + } elseif ( self::isCommandLine() ) { + self::printError( self::getText( $e ) ); + } elseif ( $mode === self::AS_PRETTY ) { + self::statusHeader( 500 ); + self::header( "Content-Type: $wgMimeType; charset=utf-8" ); + if ( $e instanceof DBConnectionError ) { + self::reportOutageHTML( $e ); + } else { + self::reportHTML( $e ); + } + } else { + self::statusHeader( 500 ); + self::header( "Content-Type: $wgMimeType; charset=utf-8" ); + if ( $eNew ) { + $message = "MediaWiki internal error.\n\n"; + if ( self::showBackTrace( $e ) ) { + $message .= 'Original exception: ' . + MWExceptionHandler::getLogMessage( $e ) . + "\nBacktrace:\n" . MWExceptionHandler::getRedactedTraceAsString( $e ) . + "\n\nException caught inside exception handler: " . + MWExceptionHandler::getLogMessage( $eNew ) . + "\nBacktrace:\n" . MWExceptionHandler::getRedactedTraceAsString( $eNew ); + } else { + $message .= 'Original exception: ' . + MWExceptionHandler::getPublicLogMessage( $e ); + $message .= "\n\nException caught inside exception handler.\n\n" . + self::getShowBacktraceError( $e ); + } + $message .= "\n"; + } else { + if ( self::showBackTrace( $e ) ) { + $message = MWExceptionHandler::getLogMessage( $e ) . + "\nBacktrace:\n" . + MWExceptionHandler::getRedactedTraceAsString( $e ) . "\n"; + } else { + $message = MWExceptionHandler::getPublicLogMessage( $e ); + } + } + echo nl2br( htmlspecialchars( $message ) ) . "\n"; + } + } + + /** + * @param Exception|Throwable $e + * @return bool Should the exception use $wgOut to output the error? + */ + private static function useOutputPage( $e ) { + // Can the extension use the Message class/wfMessage to get i18n-ed messages? + foreach ( $e->getTrace() as $frame ) { + if ( isset( $frame['class'] ) && $frame['class'] === LocalisationCache::class ) { + return false; + } + } + + // Don't even bother with OutputPage if there's no Title context set, + // (e.g. we're in RL code on load.php) - the Skin system (and probably + // most of MediaWiki) won't work. + + return ( + !empty( $GLOBALS['wgFullyInitialised'] ) && + !empty( $GLOBALS['wgOut'] ) && + RequestContext::getMain()->getTitle() && + !defined( 'MEDIAWIKI_INSTALL' ) + ); + } + + /** + * Output the exception report using HTML + * + * @param Exception|Throwable $e + */ + private static function reportHTML( $e ) { + global $wgOut, $wgSitename; + + if ( self::useOutputPage( $e ) ) { + if ( $e instanceof MWException ) { + $wgOut->prepareErrorPage( $e->getPageTitle() ); + } elseif ( $e instanceof DBReadOnlyError ) { + $wgOut->prepareErrorPage( self::msg( 'readonly', 'Database is locked' ) ); + } elseif ( $e instanceof DBExpectedError ) { + $wgOut->prepareErrorPage( self::msg( 'databaseerror', 'Database error' ) ); + } else { + $wgOut->prepareErrorPage( self::msg( 'internalerror', 'Internal error' ) ); + } + + // Show any custom GUI message before the details + if ( $e instanceof MessageSpecifier ) { + $wgOut->addHTML( Html::element( 'p', [], Message::newFromSpecifier( $e )->text() ) ); + } + $wgOut->addHTML( self::getHTML( $e ) ); + + $wgOut->output(); + } else { + self::header( 'Content-Type: text/html; charset=utf-8' ); + $pageTitle = self::msg( 'internalerror', 'Internal error' ); + echo "<!DOCTYPE html>\n" . + '<html><head>' . + // Mimick OutputPage::setPageTitle behaviour + '<title>' . + htmlspecialchars( self::msg( 'pagetitle', "$1 - $wgSitename", $pageTitle ) ) . + '</title>' . + '<style>body { font-family: sans-serif; margin: 0; padding: 0.5em 2em; }</style>' . + "</head><body>\n"; + + echo self::getHTML( $e ); + + echo "</body></html>\n"; + } + } + + /** + * If $wgShowExceptionDetails is true, return a HTML message with a + * backtrace to the error, otherwise show a message to ask to set it to true + * to show that information. + * + * @param Exception|Throwable $e + * @return string Html to output + */ + public static function getHTML( $e ) { + if ( self::showBackTrace( $e ) ) { + $html = "<div class=\"errorbox mw-content-ltr\"><p>" . + nl2br( htmlspecialchars( MWExceptionHandler::getLogMessage( $e ) ) ) . + '</p><p>Backtrace:</p><p>' . + nl2br( htmlspecialchars( MWExceptionHandler::getRedactedTraceAsString( $e ) ) ) . + "</p></div>\n"; + } else { + $logId = WebRequest::getRequestId(); + $html = "<div class=\"errorbox mw-content-ltr\">" . + htmlspecialchars( + '[' . $logId . '] ' . + gmdate( 'Y-m-d H:i:s' ) . ": " . + self::msg( "internalerror-fatal-exception", + "Fatal exception of type $1", + get_class( $e ), + $logId, + MWExceptionHandler::getURL() + ) ) . "</div>\n" . + "<!-- " . wordwrap( self::getShowBacktraceError( $e ), 50 ) . " -->"; + } + + return $html; + } + + /** + * Get a message from i18n + * + * @param string $key Message name + * @param string $fallback Default message if the message cache can't be + * called by the exception + * The function also has other parameters that are arguments for the message + * @return string Message with arguments replaced + */ + private static function msg( $key, $fallback /*[, params...] */ ) { + $args = array_slice( func_get_args(), 2 ); + try { + return wfMessage( $key, $args )->text(); + } catch ( Exception $e ) { + return wfMsgReplaceArgs( $fallback, $args ); + } + } + + /** + * @param Exception|Throwable $e + * @return string + */ + private static function getText( $e ) { + if ( self::showBackTrace( $e ) ) { + return MWExceptionHandler::getLogMessage( $e ) . + "\nBacktrace:\n" . + MWExceptionHandler::getRedactedTraceAsString( $e ) . "\n"; + } else { + return self::getShowBacktraceError( $e ) . "\n"; + } + } + + /** + * @param Exception|Throwable $e + * @return bool + */ + private static function showBackTrace( $e ) { + global $wgShowExceptionDetails, $wgShowDBErrorBacktrace; + + return ( + $wgShowExceptionDetails && + ( !( $e instanceof DBError ) || $wgShowDBErrorBacktrace ) + ); + } + + /** + * @param Exception|Throwable $e + * @return string + */ + private static function getShowBacktraceError( $e ) { + global $wgShowExceptionDetails, $wgShowDBErrorBacktrace; + $vars = []; + if ( !$wgShowExceptionDetails ) { + $vars[] = '$wgShowExceptionDetails = true;'; + } + if ( $e instanceof DBError && !$wgShowDBErrorBacktrace ) { + $vars[] = '$wgShowDBErrorBacktrace = true;'; + } + $vars = implode( ' and ', $vars ); + return "Set $vars at the bottom of LocalSettings.php to show detailed debugging information."; + } + + /** + * @return bool + */ + private static function isCommandLine() { + return !empty( $GLOBALS['wgCommandLineMode'] ); + } + + /** + * @param string $header + */ + private static function header( $header ) { + if ( !headers_sent() ) { + header( $header ); + } + } + + /** + * @param int $code + */ + private static function statusHeader( $code ) { + if ( !headers_sent() ) { + HttpStatus::header( $code ); + } + } + + /** + * Print a message, if possible to STDERR. + * Use this in command line mode only (see isCommandLine) + * + * @param string $message Failure text + */ + private static function printError( $message ) { + // NOTE: STDERR may not be available, especially if php-cgi is used from the + // command line (bug #15602). Try to produce meaningful output anyway. Using + // echo may corrupt output to STDOUT though. + if ( defined( 'STDERR' ) ) { + fwrite( STDERR, $message ); + } else { + echo $message; + } + } + + /** + * @param Exception|Throwable $e + */ + private static function reportOutageHTML( $e ) { + global $wgShowDBErrorBacktrace, $wgShowHostnames, $wgShowSQLErrors, $wgSitename; + + $sorry = htmlspecialchars( self::msg( + 'dberr-problems', + 'Sorry! This site is experiencing technical difficulties.' + ) ); + $again = htmlspecialchars( self::msg( + 'dberr-again', + 'Try waiting a few minutes and reloading.' + ) ); + + if ( $wgShowHostnames || $wgShowSQLErrors ) { + $info = str_replace( + '$1', + Html::element( 'span', [ 'dir' => 'ltr' ], $e->getMessage() ), + htmlspecialchars( self::msg( 'dberr-info', '($1)' ) ) + ); + } else { + $info = htmlspecialchars( self::msg( + 'dberr-info-hidden', + '(Cannot access the database)' + ) ); + } + + MessageCache::singleton()->disable(); // no DB access + $html = "<!DOCTYPE html>\n" . + '<html><head>' . + '<title>' . + htmlspecialchars( $wgSitename ) . + '</title>' . + '<style>body { font-family: sans-serif; margin: 0; padding: 0.5em 2em; }</style>' . + "</head><body><h1>$sorry</h1><p>$again</p><p><small>$info</small></p>"; + + if ( $wgShowDBErrorBacktrace ) { + $html .= '<p>Backtrace:</p><pre>' . + htmlspecialchars( $e->getTraceAsString() ) . '</pre>'; + } + + $html .= '</body></html>'; + echo $html; + } +} |