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