includes/context/RequestContext.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @since 1.18
  19  *
  20  * @author Alexandre Emsenhuber
  21  * @author Daniel Friesen
  22  * @file
  23  */
  24
  25 /**
  26  * Group all the pieces relevant to the context of a request into one instance
  27  */
  28 class RequestContext implements IContextSource {
  29         /**
  30          * @var WebRequest
  31          */
  32         private $request;
  33
  34         /**
  35          * @var Title
  36          */
  37         private $title;
  38
  39         /**
  40          * @var WikiPage
  41          */
  42         private $wikipage;
  43
  44         /**
  45          * @var OutputPage
  46          */
  47         private $output;
  48
  49         /**
  50          * @var User
  51          */
  52         private $user;
  53
  54         /**
  55          * @var Language
  56          */
  57         private $lang;
  58
  59         /**
  60          * @var Skin
  61          */
  62         private $skin;
  63
  64         /**
  65          * @var Config
  66          */
  67         private $config;
  68
  69         /**
  70          * @var RequestContext
  71          */
  72         private static $instance = null;
  73
  74         /**
  75          * Set the Config object
  76          *
  77          * @param Config $c
  78          */
  79         public function setConfig( Config $c ) {
  80                 $this->config = $c;
  81         }
  82
  83         /**
  84          * Get the Config object
  85          *
  86          * @return Config
  87          */
  88         public function getConfig() {
  89                 if ( $this->config === null ) {
  90                         // @todo In the future, we could move this to WebStart.php so
  91                         // the Config object is ready for when initialization happens
  92                         $this->config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
  93                 }
  94
  95                 return $this->config;
  96         }
  97
  98         /**
  99          * Set the WebRequest object
 100          *
 101          * @param WebRequest $r
 102          */
 103         public function setRequest( WebRequest $r ) {
 104                 $this->request = $r;
 105         }
 106
 107         /**
 108          * Get the WebRequest object
 109          *
 110          * @return WebRequest
 111          */
 112         public function getRequest() {
 113                 if ( $this->request === null ) {
 114                         global $wgRequest; # fallback to $wg till we can improve this
 115                         $this->request = $wgRequest;
 116                 }
 117
 118                 return $this->request;
 119         }
 120
 121         /**
 122          * Set the Title object
 123          *
 124          * @param Title $title
 125          */
 126         public function setTitle( Title $title ) {
 127                 $this->title = $title;
 128                 // Erase the WikiPage so a new one with the new title gets created.
 129                 $this->wikipage = null;
 130         }
 131
 132         /**
 133          * Get the Title object
 134          *
 135          * @return Title|null
 136          */
 137         public function getTitle() {
 138                 if ( $this->title === null ) {
 139                         global $wgTitle; # fallback to $wg till we can improve this
 140                         $this->title = $wgTitle;
 141                         wfDebugLog( 'GlobalTitleFail', __METHOD__ . ' called by ' . wfGetAllCallers( 5 ) . ' with no title set.' );
 142                 }
 143
 144                 return $this->title;
 145         }
 146
 147         /**
 148          * Check, if a Title object is set
 149          *
 150          * @since 1.25
 151          * @return bool
 152          */
 153         public function hasTitle() {
 154                 return $this->title !== null;
 155         }
 156
 157         /**
 158          * Check whether a WikiPage object can be get with getWikiPage().
 159          * Callers should expect that an exception is thrown from getWikiPage()
 160          * if this method returns false.
 161          *
 162          * @since 1.19
 163          * @return bool
 164          */
 165         public function canUseWikiPage() {
 166                 if ( $this->wikipage ) {
 167                         // If there's a WikiPage object set, we can for sure get it
 168                         return true;
 169                 }
 170                 // Only pages with legitimate titles can have WikiPages.
 171                 // That usually means pages in non-virtual namespaces.
 172                 $title = $this->getTitle();
 173                 return $title ? $title->canExist() : false;
 174         }
 175
 176         /**
 177          * Set the WikiPage object
 178          *
 179          * @since 1.19
 180          * @param WikiPage $p
 181          */
 182         public function setWikiPage( WikiPage $p ) {
 183                 $pageTitle = $p->getTitle();
 184                 if ( !$this->hasTitle() || !$pageTitle->equals( $this->getTitle() ) ) {
 185                         $this->setTitle( $pageTitle );
 186                 }
 187                 // Defer this to the end since setTitle sets it to null.
 188                 $this->wikipage = $p;
 189         }
 190
 191         /**
 192          * Get the WikiPage object.
 193          * May throw an exception if there's no Title object set or the Title object
 194          * belongs to a special namespace that doesn't have WikiPage, so use first
 195          * canUseWikiPage() to check whether this method can be called safely.
 196          *
 197          * @since 1.19
 198          * @throws MWException
 199          * @return WikiPage
 200          */
 201         public function getWikiPage() {
 202                 if ( $this->wikipage === null ) {
 203                         $title = $this->getTitle();
 204                         if ( $title === null ) {
 205                                 throw new MWException( __METHOD__ . ' called without Title object set' );
 206                         }
 207                         $this->wikipage = WikiPage::factory( $title );
 208                 }
 209
 210                 return $this->wikipage;
 211         }
 212
 213         /**
 214          * @param OutputPage $o
 215          */
 216         public function setOutput( OutputPage $o ) {
 217                 $this->output = $o;
 218         }
 219
 220         /**
 221          * Get the OutputPage object
 222          *
 223          * @return OutputPage
 224          */
 225         public function getOutput() {
 226                 if ( $this->output === null ) {
 227                         $this->output = new OutputPage( $this );
 228                 }
 229
 230                 return $this->output;
 231         }
 232
 233         /**
 234          * Set the User object
 235          *
 236          * @param User $u
 237          */
 238         public function setUser( User $u ) {
 239                 $this->user = $u;
 240         }
 241
 242         /**
 243          * Get the User object
 244          *
 245          * @return User
 246          */
 247         public function getUser() {
 248                 if ( $this->user === null ) {
 249                         $this->user = User::newFromSession( $this->getRequest() );
 250                 }
 251
 252                 return $this->user;
 253         }
 254
 255         /**
 256          * Accepts a language code and ensures it's sane. Outputs a cleaned up language
 257          * code and replaces with $wgLanguageCode if not sane.
 258          * @param string $code Language code
 259          * @return string
 260          */
 261         public static function sanitizeLangCode( $code ) {
 262                 global $wgLanguageCode;
 263
 264                 // BCP 47 - letter case MUST NOT carry meaning
 265                 $code = strtolower( $code );
 266
 267                 # Validate $code
 268                 if ( !$code || !Language::isValidCode( $code ) || $code === 'qqq' ) {
 269                         wfDebug( "Invalid user language code\n" );
 270                         $code = $wgLanguageCode;
 271                 }
 272
 273                 return $code;
 274         }
 275
 276         /**
 277          * Set the Language object
 278          *
 279          * @param Language|string $l Language instance or language code
 280          * @throws MWException
 281          * @since 1.19
 282          */
 283         public function setLanguage( $l ) {
 284                 if ( $l instanceof Language ) {
 285                         $this->lang = $l;
 286                 } elseif ( is_string( $l ) ) {
 287                         $l = self::sanitizeLangCode( $l );
 288                         $obj = Language::factory( $l );
 289                         $this->lang = $obj;
 290                 } else {
 291                         throw new MWException( __METHOD__ . " was passed an invalid type of data." );
 292                 }
 293         }
 294
 295         /**
 296          * Get the Language object.
 297          * Initialization of user or request objects can depend on this.
 298          * @return Language
 299          * @throws Exception
 300          * @since 1.19
 301          */
 302         public function getLanguage() {
 303                 if ( isset( $this->recursion ) ) {
 304                         trigger_error( "Recursion detected in " . __METHOD__, E_USER_WARNING );
 305                         $e = new Exception;
 306                         wfDebugLog( 'recursion-guard', "Recursion detected:\n" . $e->getTraceAsString() );
 307
 308                         $code = $this->getConfig()->get( 'LanguageCode' ) ?: 'en';
 309                         $this->lang = Language::factory( $code );
 310                 } elseif ( $this->lang === null ) {
 311                         $this->recursion = true;
 312
 313                         global $wgContLang;
 314
 315                         try {
 316                                 $request = $this->getRequest();
 317                                 $user = $this->getUser();
 318
 319                                 $code = $request->getVal( 'uselang', 'user' );
 320                                 if ( $code === 'user' ) {
 321                                         $code = $user->getOption( 'language' );
 322                                 }
 323                                 $code = self::sanitizeLangCode( $code );
 324
 325                                 Hooks::run( 'UserGetLanguageObject', array( $user, &$code, $this ) );
 326
 327                                 if ( $code === $this->getConfig()->get( 'LanguageCode' ) ) {
 328                                         $this->lang = $wgContLang;
 329                                 } else {
 330                                         $obj = Language::factory( $code );
 331                                         $this->lang = $obj;
 332                                 }
 333
 334                                 unset( $this->recursion );
 335                         }
 336                         catch ( Exception $ex ) {
 337                                 unset( $this->recursion );
 338                                 throw $ex;
 339                         }
 340                 }
 341
 342                 return $this->lang;
 343         }
 344
 345         /**
 346          * Set the Skin object
 347          *
 348          * @param Skin $s
 349          */
 350         public function setSkin( Skin $s ) {
 351                 $this->skin = clone $s;
 352                 $this->skin->setContext( $this );
 353         }
 354
 355         /**
 356          * Get the Skin object
 357          *
 358          * @return Skin
 359          */
 360         public function getSkin() {
 361                 if ( $this->skin === null ) {
 362
 363                         $skin = null;
 364                         Hooks::run( 'RequestContextCreateSkin', array( $this, &$skin ) );
 365                         $factory = SkinFactory::getDefaultInstance();
 366
 367                         // If the hook worked try to set a skin from it
 368                         if ( $skin instanceof Skin ) {
 369                                 $this->skin = $skin;
 370                         } elseif ( is_string( $skin ) ) {
 371                                 // Normalize the key, just in case the hook did something weird.
 372                                 $normalized = Skin::normalizeKey( $skin );
 373                                 $this->skin = $factory->makeSkin( $normalized );
 374                         }
 375
 376                         // If this is still null (the hook didn't run or didn't work)
 377                         // then go through the normal processing to load a skin
 378                         if ( $this->skin === null ) {
 379                                 if ( !in_array( 'skin', $this->getConfig()->get( 'HiddenPrefs' ) ) ) {
 380                                         # get the user skin
 381                                         $userSkin = $this->getUser()->getOption( 'skin' );
 382                                         $userSkin = $this->getRequest()->getVal( 'useskin', $userSkin );
 383                                 } else {
 384                                         # if we're not allowing users to override, then use the default
 385                                         $userSkin = $this->getConfig()->get( 'DefaultSkin' );
 386                                 }
 387
 388                                 // Normalize the key in case the user is passing gibberish
 389                                 // or has old preferences (bug 69566).
 390                                 $normalized = Skin::normalizeKey( $userSkin );
 391
 392                                 // Skin::normalizeKey will also validate it, so
 393                                 // this won't throw an exception
 394                                 $this->skin = $factory->makeSkin( $normalized );
 395                         }
 396
 397                         // After all that set a context on whatever skin got created
 398                         $this->skin->setContext( $this );
 399                 }
 400
 401                 return $this->skin;
 402         }
 403
 404         /** Helpful methods **/
 405
 406         /**
 407          * Get a Message object with context set
 408          * Parameters are the same as wfMessage()
 409          *
 410          * @return Message
 411          */
 412         public function msg() {
 413                 $args = func_get_args();
 414
 415                 return call_user_func_array( 'wfMessage', $args )->setContext( $this );
 416         }
 417
 418         /** Static methods **/
 419
 420         /**
 421          * Get the RequestContext object associated with the main request
 422          *
 423          * @return RequestContext
 424          */
 425         public static function getMain() {
 426                 if ( self::$instance === null ) {
 427                         self::$instance = new self;
 428                 }
 429
 430                 return self::$instance;
 431         }
 432
 433         /**
 434          * Get the RequestContext object associated with the main request
 435          * and gives a warning to the log, to find places, where a context maybe is missing.
 436          *
 437          * @param string $func
 438          * @return RequestContext
 439          * @since 1.24
 440          */
 441         public static function getMainAndWarn( $func = __METHOD__ ) {
 442                 wfDebug( $func . ' called without context. ' .
 443                         "Using RequestContext::getMain() for sanity\n" );
 444
 445                 return self::getMain();
 446         }
 447
 448         /**
 449          * Resets singleton returned by getMain(). Should be called only from unit tests.
 450          */
 451         public static function resetMain() {
 452                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 453                         throw new MWException( __METHOD__ . '() should be called only from unit tests!' );
 454                 }
 455                 self::$instance = null;
 456         }
 457
 458         /**
 459          * Export the resolved user IP, HTTP headers, user ID, and session ID.
 460          * The result will be reasonably sized to allow for serialization.
 461          *
 462          * @return array
 463          * @since 1.21
 464          */
 465         public function exportSession() {
 466                 return array(
 467                         'ip' => $this->getRequest()->getIP(),
 468                         'headers' => $this->getRequest()->getAllHeaders(),
 469                         'sessionId' => session_id(),
 470                         'userId' => $this->getUser()->getId()
 471                 );
 472         }
 473
 474         /**
 475          * Import an client IP address, HTTP headers, user ID, and session ID
 476          *
 477          * This sets the current session and sets $wgUser and $wgRequest.
 478          * Once the return value falls out of scope, the old context is restored.
 479          * This method should only be called in contexts (CLI or HTTP job runners)
 480          * where there is no session ID or end user receiving the response. This
 481          * is partly enforced, and is done so to avoid leaking cookies if certain
 482          * error conditions arise.
 483          *
 484          * This will setup the session from the given ID. This is useful when
 485          * background scripts inherit context when acting on behalf of a user.
 486          *
 487          * @note suhosin.session.encrypt may interfere with this method.
 488          *
 489          * @param array $params Result of RequestContext::exportSession()
 490          * @return ScopedCallback
 491          * @throws MWException
 492          * @since 1.21
 493          */
 494         public static function importScopedSession( array $params ) {
 495                 if ( session_id() != '' && strlen( $params['sessionId'] ) ) {
 496                         // Sanity check to avoid sending random cookies for the wrong users.
 497                         // This method should only called by CLI scripts or by HTTP job runners.
 498                         throw new MWException( "Sessions can only be imported when none is active." );
 499                 } elseif ( !IP::isValid( $params['ip'] ) ) {
 500                         throw new MWException( "Invalid client IP address '{$params['ip']}'." );
 501                 }
 502
 503                 if ( $params['userId'] ) { // logged-in user
 504                         $user = User::newFromId( $params['userId'] );
 505                         $user->load();
 506                         if ( !$user->getId() ) {
 507                                 throw new MWException( "No user with ID '{$params['userId']}'." );
 508                         }
 509                 } else { // anon user
 510                         $user = User::newFromName( $params['ip'], false );
 511                 }
 512
 513                 $importSessionFunc = function ( User $user, array $params ) {
 514                         global $wgRequest, $wgUser;
 515
 516                         $context = RequestContext::getMain();
 517                         // Commit and close any current session
 518                         session_write_close(); // persist
 519                         session_id( '' ); // detach
 520                         $_SESSION = array(); // clear in-memory array
 521                         // Remove any user IP or agent information
 522                         $context->setRequest( new FauxRequest() );
 523                         $wgRequest = $context->getRequest(); // b/c
 524                         // Now that all private information is detached from the user, it should
 525                         // be safe to load the new user. If errors occur or an exception is thrown
 526                         // and caught (leaving the main context in a mixed state), there is no risk
 527                         // of the User object being attached to the wrong IP, headers, or session.
 528                         $context->setUser( $user );
 529                         $wgUser = $context->getUser(); // b/c
 530                         if ( strlen( $params['sessionId'] ) ) { // don't make a new random ID
 531                                 wfSetupSession( $params['sessionId'] ); // sets $_SESSION
 532                         }
 533                         $request = new FauxRequest( array(), false, $_SESSION );
 534                         $request->setIP( $params['ip'] );
 535                         foreach ( $params['headers'] as $name => $value ) {
 536                                 $request->setHeader( $name, $value );
 537                         }
 538                         // Set the current context to use the new WebRequest
 539                         $context->setRequest( $request );
 540                         $wgRequest = $context->getRequest(); // b/c
 541                 };
 542
 543                 // Stash the old session and load in the new one
 544                 $oUser = self::getMain()->getUser();
 545                 $oParams = self::getMain()->exportSession();
 546                 $oRequest = self::getMain()->getRequest();
 547                 $importSessionFunc( $user, $params );
 548
 549                 // Set callback to save and close the new session and reload the old one
 550                 return new ScopedCallback(
 551                         function () use ( $importSessionFunc, $oUser, $oParams, $oRequest ) {
 552                                 global $wgRequest;
 553                                 $importSessionFunc( $oUser, $oParams );
 554                                 // Restore the exact previous Request object (instead of leaving FauxRequest)
 555                                 RequestContext::getMain()->setRequest( $oRequest );
 556                                 $wgRequest = RequestContext::getMain()->getRequest(); // b/c
 557                         }
 558                 );
 559         }
 560
 561         /**
 562          * Create a new extraneous context. The context is filled with information
 563          * external to the current session.
 564          * - Title is specified by argument
 565          * - Request is a FauxRequest, or a FauxRequest can be specified by argument
 566          * - User is an anonymous user, for separation IPv4 localhost is used
 567          * - Language will be based on the anonymous user and request, may be content
 568          *   language or a uselang param in the fauxrequest data may change the lang
 569          * - Skin will be based on the anonymous user, should be the wiki's default skin
 570          *
 571          * @param Title $title Title to use for the extraneous request
 572          * @param WebRequest|array $request A WebRequest or data to use for a FauxRequest
 573          * @return RequestContext
 574          */
 575         public static function newExtraneousContext( Title $title, $request = array() ) {
 576                 $context = new self;
 577                 $context->setTitle( $title );
 578                 if ( $request instanceof WebRequest ) {
 579                         $context->setRequest( $request );
 580                 } else {
 581                         $context->setRequest( new FauxRequest( $request ) );
 582                 }
 583                 $context->user = User::newFromName( '127.0.0.1', false );
 584
 585                 return $context;
 586         }
 587 }