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          * @return string
  44          */
  45         function getText() {
  46                 global $wgShowDBErrorBacktrace;
  47
  48                 $s = $this->getTextContent() . "\n";
  49
  50                 if ( $wgShowDBErrorBacktrace ) {
  51                         $s .= "Backtrace:\n" . $this->getTraceAsString() . "\n";
  52                 }
  53
  54                 return $s;
  55         }
  56
  57         /**
  58          * @return string
  59          */
  60         function getHTML() {
  61                 global $wgShowDBErrorBacktrace;
  62
  63                 $s = $this->getHTMLContent();
  64
  65                 if ( $wgShowDBErrorBacktrace ) {
  66                         $s .= '<p>Backtrace:</p><pre>' . htmlspecialchars( $this->getTraceAsString() ) . '</pre>';
  67                 }
  68
  69                 return $s;
  70         }
  71
  72         /**
  73          * @return string
  74          */
  75         protected function getTextContent() {
  76                 return $this->getMessage();
  77         }
  78
  79         /**
  80          * @return string
  81          */
  82         protected function getHTMLContent() {
  83                 return '<p>' . nl2br( htmlspecialchars( $this->getMessage() ) ) . '</p>';
  84         }
  85 }
  86
  87 /**
  88  * @ingroup Database
  89  */
  90 class DBConnectionError extends DBError {
  91         /** @var string Error text */
  92         public $error;
  93
  94         /**
  95          * @param DatabaseBase $db Object throwing the error
  96          * @param string $error Error text
  97          */
  98         function __construct( DatabaseBase $db = null, $error = 'unknown error' ) {
  99                 $msg = 'DB connection error';
 100
 101                 if ( trim( $error ) != '' ) {
 102                         $msg .= ": $error";
 103                 } elseif ( $db ) {
 104                         $error = $this->db->getServer();
 105                 }
 106
 107                 parent::__construct( $db, $msg );
 108                 $this->error = $error;
 109         }
 110
 111         /**
 112          * @return bool
 113          */
 114         function useOutputPage() {
 115                 // Not likely to work
 116                 return false;
 117         }
 118
 119         /**
 120          * @param string $key
 121          * @param string $fallback Unescaped alternative error text in case the
 122          *   message cache cannot be used. Can contain parameters as in regular
 123          *   messages, that should be passed as additional parameters.
 124          * @return string Unprocessed plain error text with parameters replaced
 125          */
 126         function msg( $key, $fallback /*[, params...] */ ) {
 127                 global $wgLang;
 128
 129                 $args = array_slice( func_get_args(), 2 );
 130
 131                 if ( $this->useMessageCache() ) {
 132                         $message = $wgLang->getMessage( $key );
 133                 } else {
 134                         $message = $fallback;
 135                 }
 136
 137                 return wfMsgReplaceArgs( $message, $args );
 138         }
 139
 140         /**
 141          * @return boolean
 142          */
 143         function isLoggable() {
 144                 // Don't send to the exception log, already in dberror log
 145                 return false;
 146         }
 147
 148         /**
 149          * @return string Safe HTML
 150          */
 151         function getHTML() {
 152                 global $wgShowDBErrorBacktrace, $wgShowHostnames, $wgShowSQLErrors;
 153
 154                 $sorry = htmlspecialchars( $this->msg(
 155                         'dberr-problems',
 156                         'Sorry! This site is experiencing technical difficulties.'
 157                 ) );
 158                 $again = htmlspecialchars( $this->msg(
 159                         'dberr-again',
 160                         'Try waiting a few minutes and reloading.'
 161                 ) );
 162
 163                 if ( $wgShowHostnames || $wgShowSQLErrors ) {
 164                         $info = str_replace(
 165                                 '$1', Html::element( 'span', array( 'dir' => 'ltr' ), $this->error ),
 166                                 htmlspecialchars( $this->msg( 'dberr-info', '(Cannot contact the database server: $1)' ) )
 167                         );
 168                 } else {
 169                         $info = htmlspecialchars( $this->msg(
 170                                 'dberr-info-hidden',
 171                                 '(Cannot contact the database server)'
 172                         ) );
 173                 }
 174
 175                 # No database access
 176                 MessageCache::singleton()->disable();
 177
 178                 $html = "<h1>$sorry</h1><p>$again</p><p><small>$info</small></p>";
 179
 180                 if ( $wgShowDBErrorBacktrace ) {
 181                         $html .= '<p>Backtrace:</p><pre>' . htmlspecialchars( $this->getTraceAsString() ) . '</pre>';
 182                 }
 183
 184                 $html .= '<hr />';
 185                 $html .= $this->searchForm();
 186
 187                 return $html;
 188         }
 189
 190         protected function getTextContent() {
 191                 global $wgShowHostnames, $wgShowSQLErrors;
 192
 193                 if ( $wgShowHostnames || $wgShowSQLErrors ) {
 194                         return $this->getMessage();
 195                 } else {
 196                         return 'DB connection error';
 197                 }
 198         }
 199
 200         /**
 201          * Output the exception report using HTML.
 202          *
 203          * @return void
 204          */
 205         public function reportHTML() {
 206                 global $wgUseFileCache;
 207
 208                 // Check whether we can serve a file-cached copy of the page with the error underneath
 209                 if ( $wgUseFileCache ) {
 210                         try {
 211                                 $cache = $this->fileCachedPage();
 212                                 // Cached version on file system?
 213                                 if ( $cache !== null ) {
 214                                         // Hack: extend the body for error messages
 215                                         $cache = str_replace( array( '</html>', '</body>' ), '', $cache );
 216                                         // Add cache notice...
 217                                         $cache .= '<div style="border:1px solid #ffd0d0;padding:1em;">' .
 218                                                 htmlspecialchars( $this->msg( 'dberr-cachederror',
 219                                                         'This is a cached copy of the requested page, and may not be up to date.' ) ) .
 220                                                 '</div>';
 221
 222                                         // Output cached page with notices on bottom and re-close body
 223                                         echo "{$cache}<hr />{$this->getHTML()}</body></html>";
 224
 225                                         return;
 226                                 }
 227                         } catch ( MWException $e ) {
 228                                 // Do nothing, just use the default page
 229                         }
 230                 }
 231
 232                 // We can't, cough and die in the usual fashion
 233                 parent::reportHTML();
 234         }
 235
 236         /**
 237          * @return string
 238          */
 239         function searchForm() {
 240                 global $wgSitename, $wgCanonicalServer, $wgRequest;
 241
 242                 $usegoogle = htmlspecialchars( $this->msg(
 243                         'dberr-usegoogle',
 244                         'You can try searching via Google in the meantime.'
 245                 ) );
 246                 $outofdate = htmlspecialchars( $this->msg(
 247                         'dberr-outofdate',
 248                         'Note that their indexes of our content may be out of date.'
 249                 ) );
 250                 $googlesearch = htmlspecialchars( $this->msg( 'searchbutton', 'Search' ) );
 251
 252                 $search = htmlspecialchars( $wgRequest->getVal( 'search' ) );
 253
 254                 $server = htmlspecialchars( $wgCanonicalServer );
 255                 $sitename = htmlspecialchars( $wgSitename );
 256
 257                 $trygoogle = <<<EOT
 258 <div style="margin: 1.5em">$usegoogle<br />
 259 <small>$outofdate</small>
 260 </div>
 261 <form method="get" action="//www.google.com/search" id="googlesearch">
 262         <input type="hidden" name="domains" value="$server" />
 263         <input type="hidden" name="num" value="50" />
 264         <input type="hidden" name="ie" value="UTF-8" />
 265         <input type="hidden" name="oe" value="UTF-8" />
 266
 267         <input type="text" name="q" size="31" maxlength="255" value="$search" />
 268         <input type="submit" name="btnG" value="$googlesearch" />
 269         <p>
 270                 <label><input type="radio" name="sitesearch" value="$server" checked="checked" />$sitename</label>
 271                 <label><input type="radio" name="sitesearch" value="" />WWW</label>
 272         </p>
 273 </form>
 274 EOT;
 275
 276                 return $trygoogle;
 277         }
 278
 279         /**
 280          * @return string
 281          */
 282         private function fileCachedPage() {
 283                 $context = RequestContext::getMain();
 284
 285                 if ( $context->getOutput()->isDisabled() ) {
 286                         // Done already?
 287                         return '';
 288                 }
 289
 290                 if ( $context->getTitle() ) {
 291                         // Use the main context's title if we managed to set it
 292                         $t = $context->getTitle()->getPrefixedDBkey();
 293                 } else {
 294                         // Fallback to the raw title URL param. We can't use the Title
 295                         // class is it may hit the interwiki table and give a DB error.
 296                         // We may get a cache miss due to not sanitizing the title though.
 297                         $t = str_replace( ' ', '_', $context->getRequest()->getVal( 'title' ) );
 298                         if ( $t == '' ) { // fallback to main page
 299                                 $t = Title::newFromText(
 300                                         $this->msg( 'mainpage', 'Main Page' ) )->getPrefixedDBkey();
 301                         }
 302                 }
 303
 304                 $cache = HTMLFileCache::newFromTitle( $t, 'view' );
 305                 if ( $cache->isCached() ) {
 306                         return $cache->fetchText();
 307                 } else {
 308                         return '';
 309                 }
 310         }
 311 }
 312
 313 /**
 314  * @ingroup Database
 315  */
 316 class DBQueryError extends DBError {
 317         public $error, $errno, $sql, $fname;
 318
 319         /**
 320          * @param DatabaseBase $db
 321          * @param string $error
 322          * @param int|string $errno
 323          * @param string $sql
 324          * @param string $fname
 325          */
 326         function __construct( DatabaseBase $db, $error, $errno, $sql, $fname ) {
 327                 $message = "A database error has occurred. Did you forget to run " .
 328                         "maintenance/update.php after upgrading?  See: " .
 329                         "https://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script\n" .
 330                         "Query: $sql\n" .
 331                         "Function: $fname\n" .
 332                         "Error: $errno $error\n";
 333                 parent::__construct( $db, $message );
 334
 335                 $this->error = $error;
 336                 $this->errno = $errno;
 337                 $this->sql = $sql;
 338                 $this->fname = $fname;
 339         }
 340
 341         /**
 342          * @return bool
 343          */
 344         function isLoggable() {
 345                 // Don't send to the exception log, already in dberror log
 346                 return false;
 347         }
 348
 349         /**
 350          * @return string
 351          */
 352         function getPageTitle() {
 353                 return $this->msg( 'databaseerror', 'Database error' );
 354         }
 355
 356         /**
 357          * @return string
 358          */
 359         protected function getHTMLContent() {
 360                 $key = 'databaseerror-text';
 361                 $s = Html::element( 'p', array(), $this->msg( $key, $this->getFallbackMessage( $key ) ) );
 362
 363                 $details = $this->getTechnicalDetails();
 364                 if ( $details ) {
 365                         $s .= '<ul>';
 366                         foreach ( $details as $key => $detail ) {
 367                                 $s .= str_replace(
 368                                         '$1', call_user_func_array( 'Html::element', $detail ),
 369                                         Html::element( 'li', array(),
 370                                                 $this->msg( $key, $this->getFallbackMessage( $key ) )
 371                                         )
 372                                 );
 373                         }
 374                         $s .= '</ul>';
 375                 }
 376
 377                 return $s;
 378         }
 379
 380         /**
 381          * @return string
 382          */
 383         protected function getTextContent() {
 384                 $key = 'databaseerror-textcl';
 385                 $s = $this->msg( $key, $this->getFallbackMessage( $key ) ) . "\n";
 386
 387                 foreach ( $this->getTechnicalDetails() as $key => $detail ) {
 388                         $s .= $this->msg( $key, $this->getFallbackMessage( $key ), $detail[2] ) . "\n";
 389                 }
 390
 391                 return $s;
 392         }
 393
 394         /**
 395          * Make a list of technical details that can be shown to the user. This information can
 396          * aid in debugging yet may be useful to an attacker trying to exploit a security weakness
 397          * in the software or server configuration.
 398          *
 399          * Thus no such details are shown by default, though if $wgShowHostnames is true, only the
 400          * full SQL query is hidden; in fact, the error message often does contain a hostname, and
 401          * sites using this option probably don't care much about "security by obscurity". Of course,
 402          * if $wgShowSQLErrors is true, the SQL query *is* shown.
 403          *
 404          * @return array Keys are message keys; values are arrays of arguments for Html::element().
 405          *   Array will be empty if users are not allowed to see any of these details at all.
 406          */
 407         protected function getTechnicalDetails() {
 408                 global $wgShowHostnames, $wgShowSQLErrors;
 409
 410                 $attribs = array( 'dir' => 'ltr' );
 411                 $details = array();
 412
 413                 if ( $wgShowSQLErrors ) {
 414                         $details['databaseerror-query'] = array(
 415                                 'div', array( 'class' => 'mw-code' ) + $attribs, $this->sql );
 416                 }
 417
 418                 if ( $wgShowHostnames || $wgShowSQLErrors ) {
 419                         $errorMessage = $this->errno . ' ' . $this->error;
 420                         $details['databaseerror-function'] = array( 'code', $attribs, $this->fname );
 421                         $details['databaseerror-error'] = array( 'samp', $attribs, $errorMessage );
 422                 }
 423
 424                 return $details;
 425         }
 426
 427         /**
 428          * @param string $key Message key
 429          * @return string English message text
 430          */
 431         private function getFallbackMessage( $key ) {
 432                 $messages = array(
 433                         'databaseerror-text' => 'A database query error has occurred.
 434 This may indicate a bug in the software.',
 435                         'databaseerror-textcl' => 'A database query error has occurred.',
 436                         'databaseerror-query' => 'Query: $1',
 437                         'databaseerror-function' => 'Function: $1',
 438                         'databaseerror-error' => 'Error: $1',
 439                 );
 440
 441                 return $messages[$key];
 442         }
 443 }
 444
 445 /**
 446  * @ingroup Database
 447  */
 448 class DBUnexpectedError extends DBError {
 449 }