includes/db/DatabaseError.php

   1 <?php
   2 /**
   3  * This file contains database error classes.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Database
  22  */
  23
  24 /**
  25  * Database error base class
  26  * @ingroup Database
  27  */
  28 class DBError extends MWException {
  29         /** @var DatabaseBase */
  30         public $db;
  31
  32         /**
  33          * Construct a database error
  34          * @param DatabaseBase $db Object which threw the error
  35          * @param string $error A simple error message to be used for debugging
  36          */
  37         function __construct( DatabaseBase $db = null, $error ) {
  38                 $this->db = $db;
  39                 parent::__construct( $error );
  40         }
  41 }
  42
  43 /**
  44  * Base class for the more common types of database errors. These are known to occur
  45  * frequently, so we try to give friendly error messages for them.
  46  *
  47  * @ingroup Database
  48  * @since 1.23
  49  */
  50 class DBExpectedError extends DBError {
  51         /**
  52          * @return string
  53          */
  54         function getText() {
  55                 global $wgShowDBErrorBacktrace;
  56
  57                 $s = $this->getTextContent() . "\n";
  58
  59                 if ( $wgShowDBErrorBacktrace ) {
  60                         $s .= "Backtrace:\n" . $this->getTraceAsString() . "\n";
  61                 }
  62
  63                 return $s;
  64         }
  65
  66         /**
  67          * @return string
  68          */
  69         function getHTML() {
  70                 global $wgShowDBErrorBacktrace;
  71
  72                 $s = $this->getHTMLContent();
  73
  74                 if ( $wgShowDBErrorBacktrace ) {
  75                         $s .= '<p>Backtrace:</p><pre>' . htmlspecialchars( $this->getTraceAsString() ) . '</pre>';
  76                 }
  77
  78                 return $s;
  79         }
  80
  81         /**
  82          * @return string
  83          */
  84         protected function getTextContent() {
  85                 return $this->getMessage();
  86         }
  87
  88         /**
  89          * @return string
  90          */
  91         protected function getHTMLContent() {
  92                 return '<p>' . nl2br( htmlspecialchars( $this->getTextContent() ) ) . '</p>';
  93         }
  94 }
  95
  96 /**
  97  * @ingroup Database
  98  */
  99 class DBConnectionError extends DBExpectedError {
 100         /** @var string Error text */
 101         public $error;
 102
 103         /**
 104          * @param DatabaseBase $db Object throwing the error
 105          * @param string $error Error text
 106          */
 107         function __construct( DatabaseBase $db = null, $error = 'unknown error' ) {
 108                 $msg = 'DB connection error';
 109
 110                 if ( trim( $error ) != '' ) {
 111                         $msg .= ": $error";
 112                 } elseif ( $db ) {
 113                         $error = $this->db->getServer();
 114                 }
 115
 116                 parent::__construct( $db, $msg );
 117                 $this->error = $error;
 118         }
 119
 120         /**
 121          * @return bool
 122          */
 123         function useOutputPage() {
 124                 // Not likely to work
 125                 return false;
 126         }
 127
 128         /**
 129          * @param string $key
 130          * @param string $fallback Unescaped alternative error text in case the
 131          *   message cache cannot be used. Can contain parameters as in regular
 132          *   messages, that should be passed as additional parameters.
 133          * @return string Unprocessed plain error text with parameters replaced
 134          */
 135         function msg( $key, $fallback /*[, params...] */ ) {
 136                 $args = array_slice( func_get_args(), 2 );
 137
 138                 if ( $this->useMessageCache() ) {
 139                         $msg = wfMessage( $key )->useDatabase( false );
 140                 } else {
 141                         $msg = new RawMessage( $fallback );
 142                 }
 143
 144                 return $msg->params( $args )->text();
 145         }
 146
 147         /**
 148          * @return bool
 149          */
 150         function isLoggable() {
 151                 // Don't send to the exception log, already in dberror log
 152                 return false;
 153         }
 154
 155         /**
 156          * @return string Safe HTML
 157          */
 158         function getHTML() {
 159                 global $wgShowDBErrorBacktrace, $wgShowHostnames, $wgShowSQLErrors;
 160
 161                 $sorry = htmlspecialchars( $this->msg(
 162                         'dberr-problems',
 163                         'Sorry! This site is experiencing technical difficulties.'
 164                 ) );
 165                 $again = htmlspecialchars( $this->msg(
 166                         'dberr-again',
 167                         'Try waiting a few minutes and reloading.'
 168                 ) );
 169
 170                 if ( $wgShowHostnames || $wgShowSQLErrors ) {
 171                         $info = str_replace(
 172                                 '$1', Html::element( 'span', array( 'dir' => 'ltr' ), $this->error ),
 173                                 htmlspecialchars( $this->msg( 'dberr-info', '(Cannot contact the database server: $1)' ) )
 174                         );
 175                 } else {
 176                         $info = htmlspecialchars( $this->msg(
 177                                 'dberr-info-hidden',
 178                                 '(Cannot contact the database server)'
 179                         ) );
 180                 }
 181
 182                 # No database access
 183                 MessageCache::singleton()->disable();
 184
 185                 $html = "<h1>$sorry</h1><p>$again</p><p><small>$info</small></p>";
 186
 187                 if ( $wgShowDBErrorBacktrace ) {
 188                         $html .= '<p>Backtrace:</p><pre>' . htmlspecialchars( $this->getTraceAsString() ) . '</pre>';
 189                 }
 190
 191                 $html .= '<hr />';
 192                 $html .= $this->searchForm();
 193
 194                 return $html;
 195         }
 196
 197         protected function getTextContent() {
 198                 global $wgShowHostnames, $wgShowSQLErrors;
 199
 200                 if ( $wgShowHostnames || $wgShowSQLErrors ) {
 201                         return $this->getMessage();
 202                 } else {
 203                         return 'DB connection error';
 204                 }
 205         }
 206
 207         /**
 208          * Output the exception report using HTML.
 209          *
 210          * @return void
 211          */
 212         public function reportHTML() {
 213                 global $wgUseFileCache;
 214
 215                 // Check whether we can serve a file-cached copy of the page with the error underneath
 216                 if ( $wgUseFileCache ) {
 217                         try {
 218                                 $cache = $this->fileCachedPage();
 219                                 // Cached version on file system?
 220                                 if ( $cache !== null ) {
 221                                         // Hack: extend the body for error messages
 222                                         $cache = str_replace( array( '</html>', '</body>' ), '', $cache );
 223                                         // Add cache notice...
 224                                         $cache .= '<div style="border:1px solid #ffd0d0;padding:1em;">' .
 225                                                 htmlspecialchars( $this->msg( 'dberr-cachederror',
 226                                                         'This is a cached copy of the requested page, and may not be up to date.' ) ) .
 227                                                 '</div>';
 228
 229                                         // Output cached page with notices on bottom and re-close body
 230                                         echo "{$cache}<hr />{$this->getHTML()}</body></html>";
 231
 232                                         return;
 233                                 }
 234                         } catch ( MWException $e ) {
 235                                 // Do nothing, just use the default page
 236                         }
 237                 }
 238
 239                 // We can't, cough and die in the usual fashion
 240                 parent::reportHTML();
 241         }
 242
 243         /**
 244          * @return string
 245          */
 246         function searchForm() {
 247                 global $wgSitename, $wgCanonicalServer, $wgRequest;
 248
 249                 $usegoogle = htmlspecialchars( $this->msg(
 250                         'dberr-usegoogle',
 251                         'You can try searching via Google in the meantime.'
 252                 ) );
 253                 $outofdate = htmlspecialchars( $this->msg(
 254                         'dberr-outofdate',
 255                         'Note that their indexes of our content may be out of date.'
 256                 ) );
 257                 $googlesearch = htmlspecialchars( $this->msg( 'searchbutton', 'Search' ) );
 258
 259                 $search = htmlspecialchars( $wgRequest->getVal( 'search' ) );
 260
 261                 $server = htmlspecialchars( $wgCanonicalServer );
 262                 $sitename = htmlspecialchars( $wgSitename );
 263
 264                 $trygoogle = <<<EOT
 265 <div style="margin: 1.5em">$usegoogle<br />
 266 <small>$outofdate</small>
 267 </div>
 268 <form method="get" action="//www.google.com/search" id="googlesearch">
 269         <input type="hidden" name="domains" value="$server" />
 270         <input type="hidden" name="num" value="50" />
 271         <input type="hidden" name="ie" value="UTF-8" />
 272         <input type="hidden" name="oe" value="UTF-8" />
 273
 274         <input type="text" name="q" size="31" maxlength="255" value="$search" />
 275         <input type="submit" name="btnG" value="$googlesearch" />
 276         <p>
 277                 <label><input type="radio" name="sitesearch" value="$server" checked="checked" />$sitename</label>
 278                 <label><input type="radio" name="sitesearch" value="" />WWW</label>
 279         </p>
 280 </form>
 281 EOT;
 282
 283                 return $trygoogle;
 284         }
 285
 286         /**
 287          * @return string
 288          */
 289         private function fileCachedPage() {
 290                 $context = RequestContext::getMain();
 291
 292                 if ( $context->getOutput()->isDisabled() ) {
 293                         // Done already?
 294                         return '';
 295                 }
 296
 297                 if ( $context->getTitle() ) {
 298                         // Use the main context's title if we managed to set it
 299                         $t = $context->getTitle()->getPrefixedDBkey();
 300                 } else {
 301                         // Fallback to the raw title URL param. We can't use the Title
 302                         // class is it may hit the interwiki table and give a DB error.
 303                         // We may get a cache miss due to not sanitizing the title though.
 304                         $t = str_replace( ' ', '_', $context->getRequest()->getVal( 'title' ) );
 305                         if ( $t == '' ) { // fallback to main page
 306                                 $t = Title::newFromText(
 307                                         $this->msg( 'mainpage', 'Main Page' ) )->getPrefixedDBkey();
 308                         }
 309                 }
 310
 311                 $cache = new HTMLFileCache( $t, 'view' );
 312                 if ( $cache->isCached() ) {
 313                         return $cache->fetchText();
 314                 } else {
 315                         return '';
 316                 }
 317         }
 318 }
 319
 320 /**
 321  * @ingroup Database
 322  */
 323 class DBQueryError extends DBExpectedError {
 324         public $error, $errno, $sql, $fname;
 325
 326         /**
 327          * @param DatabaseBase $db
 328          * @param string $error
 329          * @param int|string $errno
 330          * @param string $sql
 331          * @param string $fname
 332          */
 333         function __construct( DatabaseBase $db, $error, $errno, $sql, $fname ) {
 334                 $message = "A database error has occurred. Did you forget to run " .
 335                         "maintenance/update.php after upgrading?  See: " .
 336                         "https://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script\n" .
 337                         "Query: $sql\n" .
 338                         "Function: $fname\n" .
 339                         "Error: $errno $error\n";
 340                 parent::__construct( $db, $message );
 341
 342                 $this->error = $error;
 343                 $this->errno = $errno;
 344                 $this->sql = $sql;
 345                 $this->fname = $fname;
 346         }
 347
 348         /**
 349          * @return string
 350          */
 351         function getPageTitle() {
 352                 return $this->msg( 'databaseerror', 'Database error' );
 353         }
 354
 355         /**
 356          * @return string
 357          */
 358         protected function getHTMLContent() {
 359                 $key = 'databaseerror-text';
 360                 $s = Html::element( 'p', array(), $this->msg( $key, $this->getFallbackMessage( $key ) ) );
 361
 362                 $details = $this->getTechnicalDetails();
 363                 if ( $details ) {
 364                         $s .= '<ul>';
 365                         foreach ( $details as $key => $detail ) {
 366                                 $s .= str_replace(
 367                                         '$1', call_user_func_array( 'Html::element', $detail ),
 368                                         Html::element( 'li', array(),
 369                                                 $this->msg( $key, $this->getFallbackMessage( $key ) )
 370                                         )
 371                                 );
 372                         }
 373                         $s .= '</ul>';
 374                 }
 375
 376                 return $s;
 377         }
 378
 379         /**
 380          * @return string
 381          */
 382         protected function getTextContent() {
 383                 $key = 'databaseerror-textcl';
 384                 $s = $this->msg( $key, $this->getFallbackMessage( $key ) ) . "\n";
 385
 386                 foreach ( $this->getTechnicalDetails() as $key => $detail ) {
 387                         $s .= $this->msg( $key, $this->getFallbackMessage( $key ), $detail[2] ) . "\n";
 388                 }
 389
 390                 return $s;
 391         }
 392
 393         /**
 394          * Make a list of technical details that can be shown to the user. This information can
 395          * aid in debugging yet may be useful to an attacker trying to exploit a security weakness
 396          * in the software or server configuration.
 397          *
 398          * Thus no such details are shown by default, though if $wgShowHostnames is true, only the
 399          * full SQL query is hidden; in fact, the error message often does contain a hostname, and
 400          * sites using this option probably don't care much about "security by obscurity". Of course,
 401          * if $wgShowSQLErrors is true, the SQL query *is* shown.
 402          *
 403          * @return array Keys are message keys; values are arrays of arguments for Html::element().
 404          *   Array will be empty if users are not allowed to see any of these details at all.
 405          */
 406         protected function getTechnicalDetails() {
 407                 global $wgShowHostnames, $wgShowSQLErrors;
 408
 409                 $attribs = array( 'dir' => 'ltr' );
 410                 $details = array();
 411
 412                 if ( $wgShowSQLErrors ) {
 413                         $details['databaseerror-query'] = array(
 414                                 'div', array( 'class' => 'mw-code' ) + $attribs, $this->sql );
 415                 }
 416
 417                 if ( $wgShowHostnames || $wgShowSQLErrors ) {
 418                         $errorMessage = $this->errno . ' ' . $this->error;
 419                         $details['databaseerror-function'] = array( 'code', $attribs, $this->fname );
 420                         $details['databaseerror-error'] = array( 'samp', $attribs, $errorMessage );
 421                 }
 422
 423                 return $details;
 424         }
 425
 426         /**
 427          * @param string $key Message key
 428          * @return string English message text
 429          */
 430         private function getFallbackMessage( $key ) {
 431                 $messages = array(
 432                         'databaseerror-text' => 'A database query error has occurred.
 433 This may indicate a bug in the software.',
 434                         'databaseerror-textcl' => 'A database query error has occurred.',
 435                         'databaseerror-query' => 'Query: $1',
 436                         'databaseerror-function' => 'Function: $1',
 437                         'databaseerror-error' => 'Error: $1',
 438                 );
 439
 440                 return $messages[$key];
 441         }
 442 }
 443
 444 /**
 445  * @ingroup Database
 446  */
 447 class DBUnexpectedError extends DBError {
 448 }