includes/context/RequestContext.php

   1 <?php
   2 /**
   3  * Container for request-dependant objects and site configuration
   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  * @since 1.18
  21  *
  22  * @author Alexandre Emsenhuber
  23  * @author Daniel Friesen
  24  * @file
  25  */
  26
  27 /**
  28  * Group all the pieces relevant to the context of a request into one instance
  29  */
  30 class RequestContext implements IContextSource {
  31         /**
  32          * @var WebRequest
  33          */
  34         private $request;
  35
  36         /**
  37          * @var Title
  38          */
  39         private $title;
  40
  41         /**
  42          * @var WikiPage
  43          */
  44         private $wikipage;
  45
  46         /**
  47          * @var OutputPage
  48          */
  49         private $output;
  50
  51         /**
  52          * @var User
  53          */
  54         private $user;
  55
  56         /**
  57          * @var Language
  58          */
  59         private $lang;
  60
  61         /**
  62          * @var Skin
  63          */
  64         private $skin;
  65
  66         /**
  67          * @var Config
  68          */
  69         private $config;
  70
  71         /**
  72          * @var RequestContext
  73          */
  74         private static $instance = null;
  75
  76         /**
  77          * Set the Config object
  78          *
  79          * @param Config $c
  80          */
  81         public function setConfig( Config $c ) {
  82                 $this->config = $c;
  83         }
  84
  85         /**
  86          * Get the Config object
  87          *
  88          * @return Config
  89          */
  90         public function getConfig() {
  91                 if ( $this->config === null ) {
  92                         // @todo In the future, we could move this to WebStart.php so
  93                         // the Config object is ready for when initialization happens
  94                         $this->config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
  95                 }
  96
  97                 return $this->config;
  98         }
  99
 100         /**
 101          * Set the WebRequest object
 102          *
 103          * @param WebRequest $r
 104          */
 105         public function setRequest( WebRequest $r ) {
 106                 $this->request = $r;
 107         }
 108
 109         /**
 110          * Get the WebRequest object
 111          *
 112          * @return WebRequest
 113          */
 114         public function getRequest() {
 115                 if ( $this->request === null ) {
 116                         global $wgRequest; # fallback to $wg till we can improve this
 117                         $this->request = $wgRequest;
 118                 }
 119
 120                 return $this->request;
 121         }
 122
 123         /**
 124          * Set the Title object
 125          *
 126          * @param Title $title
 127          */
 128         public function setTitle( Title $title ) {
 129                 $this->title = $title;
 130                 // Erase the WikiPage so a new one with the new title gets created.
 131                 $this->wikipage = null;
 132         }
 133
 134         /**
 135          * Get the Title object
 136          *
 137          * @return Title|null
 138          */
 139         public function getTitle() {
 140                 if ( $this->title === null ) {
 141                         global $wgTitle; # fallback to $wg till we can improve this
 142                         $this->title = $wgTitle;
 143                         wfDebugLog( 'GlobalTitleFail', __METHOD__ . ' called by ' . wfGetAllCallers( 5 ) . ' with no title set.' );
 144                 }
 145
 146                 return $this->title;
 147         }
 148
 149         /**
 150          * Check, if a Title object is set
 151          *
 152          * @since 1.25
 153          * @return bool
 154          */
 155         public function hasTitle() {
 156                 return $this->title !== null;
 157         }
 158
 159         /**
 160          * Check whether a WikiPage object can be get with getWikiPage().
 161          * Callers should expect that an exception is thrown from getWikiPage()
 162          * if this method returns false.
 163          *
 164          * @since 1.19
 165          * @return bool
 166          */
 167         public function canUseWikiPage() {
 168                 if ( $this->wikipage ) {
 169                         // If there's a WikiPage object set, we can for sure get it
 170                         return true;
 171                 }
 172                 // Only pages with legitimate titles can have WikiPages.
 173                 // That usually means pages in non-virtual namespaces.
 174                 $title = $this->getTitle();
 175                 return $title ? $title->canExist() : false;
 176         }
 177
 178         /**
 179          * Set the WikiPage object
 180          *
 181          * @since 1.19
 182          * @param WikiPage $p
 183          */
 184         public function setWikiPage( WikiPage $p ) {
 185                 $pageTitle = $p->getTitle();
 186                 if ( !$this->hasTitle() || !$pageTitle->equals( $this->getTitle() ) ) {
 187                         $this->setTitle( $pageTitle );
 188                 }
 189                 // Defer this to the end since setTitle sets it to null.
 190                 $this->wikipage = $p;
 191         }
 192
 193         /**
 194          * Get the WikiPage object.
 195          * May throw an exception if there's no Title object set or the Title object
 196          * belongs to a special namespace that doesn't have WikiPage, so use first
 197          * canUseWikiPage() to check whether this method can be called safely.
 198          *
 199          * @since 1.19
 200          * @throws MWException
 201          * @return WikiPage
 202          */
 203         public function getWikiPage() {
 204                 if ( $this->wikipage === null ) {
 205                         $title = $this->getTitle();
 206                         if ( $title === null ) {
 207                                 throw new MWException( __METHOD__ . ' called without Title object set' );
 208                         }
 209                         $this->wikipage = WikiPage::factory( $title );
 210                 }
 211
 212                 return $this->wikipage;
 213         }
 214
 215         /**
 216          * @param OutputPage $o
 217          */
 218         public function setOutput( OutputPage $o ) {
 219                 $this->output = $o;
 220         }
 221
 222         /**
 223          * Get the OutputPage object
 224          *
 225          * @return OutputPage
 226          */
 227         public function getOutput() {
 228                 if ( $this->output === null ) {
 229                         $this->output = new OutputPage( $this );
 230                 }
 231
 232                 return $this->output;
 233         }
 234
 235         /**
 236          * Set the User object
 237          *
 238          * @param User $u
 239          */
 240         public function setUser( User $u ) {
 241                 $this->user = $u;
 242         }
 243
 244         /**
 245          * Get the User object
 246          *
 247          * @return User
 248          */
 249         public function getUser() {
 250                 if ( $this->user === null ) {
 251                         $this->user = User::newFromSession( $this->getRequest() );
 252                 }
 253
 254                 return $this->user;
 255         }
 256
 257         /**
 258          * Accepts a language code and ensures it's sane. Outputs a cleaned up language
 259          * code and replaces with $wgLanguageCode if not sane.
 260          * @param string $code Language code
 261          * @return string
 262          */
 263         public static function sanitizeLangCode( $code ) {
 264                 global $wgLanguageCode;
 265
 266                 // BCP 47 - letter case MUST NOT carry meaning
 267                 $code = strtolower( $code );
 268
 269                 # Validate $code
 270                 if ( !$code || !Language::isValidCode( $code ) || $code === 'qqq' ) {
 271                         wfDebug( "Invalid user language code\n" );
 272                         $code = $wgLanguageCode;
 273                 }
 274
 275                 return $code;
 276         }
 277
 278         /**
 279          * Set the Language object
 280          *
 281          * @param Language|string $l Language instance or language code
 282          * @throws MWException
 283          * @since 1.19
 284          */
 285         public function setLanguage( $l ) {
 286                 if ( $l instanceof Language ) {
 287                         $this->lang = $l;
 288                 } elseif ( is_string( $l ) ) {
 289                         $l = self::sanitizeLangCode( $l );
 290                         $obj = Language::factory( $l );
 291                         $this->lang = $obj;
 292                 } else {
 293                         throw new MWException( __METHOD__ . " was passed an invalid type of data." );
 294                 }
 295         }
 296
 297         /**
 298          * Get the Language object.
 299          * Initialization of user or request objects can depend on this.
 300          * @return Language
 301          * @throws Exception
 302          * @since 1.19
 303          */
 304         public function getLanguage() {
 305                 if ( isset( $this->recursion ) ) {
 306                         trigger_error( "Recursion detected in " . __METHOD__, E_USER_WARNING );
 307                         $e = new Exception;
 308                         wfDebugLog( 'recursion-guard', "Recursion detected:\n" . $e->getTraceAsString() );
 309
 310                         $code = $this->getConfig()->get( 'LanguageCode' ) ?: 'en';
 311                         $this->lang = Language::factory( $code );
 312                 } elseif ( $this->lang === null ) {
 313                         $this->recursion = true;
 314
 315                         global $wgContLang;
 316
 317                         try {
 318                                 $request = $this->getRequest();
 319                                 $user = $this->getUser();
 320
 321                                 $code = $request->getVal( 'uselang', 'user' );
 322                                 if ( $code === 'user' ) {
 323                                         $code = $user->getOption( 'language' );
 324                                 }
 325                                 $code = self::sanitizeLangCode( $code );
 326
 327                                 Hooks::run( 'UserGetLanguageObject', array( $user, &$code, $this ) );
 328
 329                                 if ( $code === $this->getConfig()->get( 'LanguageCode' ) ) {
 330                                         $this->lang = $wgContLang;
 331                                 } else {
 332                                         $obj = Language::factory( $code );
 333                                         $this->lang = $obj;
 334                                 }
 335
 336                                 unset( $this->recursion );
 337                         }
 338                         catch ( Exception $ex ) {
 339                                 unset( $this->recursion );
 340                                 throw $ex;
 341                         }
 342                 }
 343
 344                 return $this->lang;
 345         }
 346
 347         /**
 348          * Set the Skin object
 349          *
 350          * @param Skin $s
 351          */
 352         public function setSkin( Skin $s ) {
 353                 $this->skin = clone $s;
 354                 $this->skin->setContext( $this );
 355         }
 356
 357         /**
 358          * Get the Skin object
 359          *
 360          * @return Skin
 361          */
 362         public function getSkin() {
 363                 if ( $this->skin === null ) {
 364
 365                         $skin = null;
 366                         Hooks::run( 'RequestContextCreateSkin', array( $this, &$skin ) );
 367                         $factory = SkinFactory::getDefaultInstance();
 368
 369                         // If the hook worked try to set a skin from it
 370                         if ( $skin instanceof Skin ) {
 371                                 $this->skin = $skin;
 372                         } elseif ( is_string( $skin ) ) {
 373                                 // Normalize the key, just in case the hook did something weird.
 374                                 $normalized = Skin::normalizeKey( $skin );
 375                                 $this->skin = $factory->makeSkin( $normalized );
 376                         }
 377
 378                         // If this is still null (the hook didn't run or didn't work)
 379                         // then go through the normal processing to load a skin
 380                         if ( $this->skin === null ) {
 381                                 if ( !in_array( 'skin', $this->getConfig()->get( 'HiddenPrefs' ) ) ) {
 382                                         # get the user skin
 383                                         $userSkin = $this->getUser()->getOption( 'skin' );
 384                                         $userSkin = $this->getRequest()->getVal( 'useskin', $userSkin );
 385                                 } else {
 386                                         # if we're not allowing users to override, then use the default
 387                                         $userSkin = $this->getConfig()->get( 'DefaultSkin' );
 388                                 }
 389
 390                                 // Normalize the key in case the user is passing gibberish
 391                                 // or has old preferences (bug 69566).
 392                                 $normalized = Skin::normalizeKey( $userSkin );
 393
 394                                 // Skin::normalizeKey will also validate it, so
 395                                 // this won't throw an exception
 396                                 $this->skin = $factory->makeSkin( $normalized );
 397                         }
 398
 399                         // After all that set a context on whatever skin got created
 400                         $this->skin->setContext( $this );
 401                 }
 402
 403                 return $this->skin;
 404         }
 405
 406         /** Helpful methods **/
 407
 408         /**
 409          * Get a Message object with context set
 410          * Parameters are the same as wfMessage()
 411          *
 412          * @return Message
 413          */
 414         public function msg() {
 415                 $args = func_get_args();
 416
 417                 return call_user_func_array( 'wfMessage', $args )->setContext( $this );
 418         }
 419
 420         /** Static methods **/
 421
 422         /**
 423          * Get the RequestContext object associated with the main request
 424          *
 425          * @return RequestContext
 426          */
 427         public static function getMain() {
 428                 if ( self::$instance === null ) {
 429                         self::$instance = new self;
 430                 }
 431
 432                 return self::$instance;
 433         }
 434
 435         /**
 436          * Get the RequestContext object associated with the main request
 437          * and gives a warning to the log, to find places, where a context maybe is missing.
 438          *
 439          * @param string $func
 440          * @return RequestContext
 441          * @since 1.24
 442          */
 443         public static function getMainAndWarn( $func = __METHOD__ ) {
 444                 wfDebug( $func . ' called without context. ' .
 445                         "Using RequestContext::getMain() for sanity\n" );
 446
 447                 return self::getMain();
 448         }
 449
 450         /**
 451          * Resets singleton returned by getMain(). Should be called only from unit tests.
 452          */
 453         public static function resetMain() {
 454                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 455                         throw new MWException( __METHOD__ . '() should be called only from unit tests!' );
 456                 }
 457                 self::$instance = null;
 458         }
 459
 460         /**
 461          * Export the resolved user IP, HTTP headers, user ID, and session ID.
 462          * The result will be reasonably sized to allow for serialization.
 463          *
 464          * @return array
 465          * @since 1.21
 466          */
 467         public function exportSession() {
 468                 return array(
 469                         'ip' => $this->getRequest()->getIP(),
 470                         'headers' => $this->getRequest()->getAllHeaders(),
 471                         'sessionId' => session_id(),
 472                         'userId' => $this->getUser()->getId()
 473                 );
 474         }
 475
 476         /**
 477          * Import an client IP address, HTTP headers, user ID, and session ID
 478          *
 479          * This sets the current session and sets $wgUser and $wgRequest.
 480          * Once the return value falls out of scope, the old context is restored.
 481          * This method should only be called in contexts (CLI or HTTP job runners)
 482          * where there is no session ID or end user receiving the response. This
 483          * is partly enforced, and is done so to avoid leaking cookies if certain
 484          * error conditions arise.
 485          *
 486          * This will setup the session from the given ID. This is useful when
 487          * background scripts inherit context when acting on behalf of a user.
 488          *
 489          * @note suhosin.session.encrypt may interfere with this method.
 490          *
 491          * @param array $params Result of RequestContext::exportSession()
 492          * @return ScopedCallback
 493          * @throws MWException
 494          * @since 1.21
 495          */
 496         public static function importScopedSession( array $params ) {
 497                 if ( session_id() != '' && strlen( $params['sessionId'] ) ) {
 498                         // Sanity check to avoid sending random cookies for the wrong users.
 499                         // This method should only called by CLI scripts or by HTTP job runners.
 500                         throw new MWException( "Sessions can only be imported when none is active." );
 501                 } elseif ( !IP::isValid( $params['ip'] ) ) {
 502                         throw new MWException( "Invalid client IP address '{$params['ip']}'." );
 503                 }
 504
 505                 if ( $params['userId'] ) { // logged-in user
 506                         $user = User::newFromId( $params['userId'] );
 507                         $user->load();
 508                         if ( !$user->getId() ) {
 509                                 throw new MWException( "No user with ID '{$params['userId']}'." );
 510                         }
 511                 } else { // anon user
 512                         $user = User::newFromName( $params['ip'], false );
 513                 }
 514
 515                 $importSessionFunc = function ( User $user, array $params ) {
 516                         global $wgRequest, $wgUser;
 517
 518                         $context = RequestContext::getMain();
 519                         // Commit and close any current session
 520                         session_write_close(); // persist
 521                         session_id( '' ); // detach
 522                         $_SESSION = array(); // clear in-memory array
 523                         // Remove any user IP or agent information
 524                         $context->setRequest( new FauxRequest() );
 525                         $wgRequest = $context->getRequest(); // b/c
 526                         // Now that all private information is detached from the user, it should
 527                         // be safe to load the new user. If errors occur or an exception is thrown
 528                         // and caught (leaving the main context in a mixed state), there is no risk
 529                         // of the User object being attached to the wrong IP, headers, or session.
 530                         $context->setUser( $user );
 531                         $wgUser = $context->getUser(); // b/c
 532                         if ( strlen( $params['sessionId'] ) ) { // don't make a new random ID
 533                                 wfSetupSession( $params['sessionId'] ); // sets $_SESSION
 534                         }
 535                         $request = new FauxRequest( array(), false, $_SESSION );
 536                         $request->setIP( $params['ip'] );
 537                         foreach ( $params['headers'] as $name => $value ) {
 538                                 $request->setHeader( $name, $value );
 539                         }
 540                         // Set the current context to use the new WebRequest
 541                         $context->setRequest( $request );
 542                         $wgRequest = $context->getRequest(); // b/c
 543                 };
 544
 545                 // Stash the old session and load in the new one
 546                 $oUser = self::getMain()->getUser();
 547                 $oParams = self::getMain()->exportSession();
 548                 $oRequest = self::getMain()->getRequest();
 549                 $importSessionFunc( $user, $params );
 550
 551                 // Set callback to save and close the new session and reload the old one
 552                 return new ScopedCallback(
 553                         function () use ( $importSessionFunc, $oUser, $oParams, $oRequest ) {
 554                                 global $wgRequest;
 555                                 $importSessionFunc( $oUser, $oParams );
 556                                 // Restore the exact previous Request object (instead of leaving FauxRequest)
 557                                 RequestContext::getMain()->setRequest( $oRequest );
 558                                 $wgRequest = RequestContext::getMain()->getRequest(); // b/c
 559                         }
 560                 );
 561         }
 562
 563         /**
 564          * Create a new extraneous context. The context is filled with information
 565          * external to the current session.
 566          * - Title is specified by argument
 567          * - Request is a FauxRequest, or a FauxRequest can be specified by argument
 568          * - User is an anonymous user, for separation IPv4 localhost is used
 569          * - Language will be based on the anonymous user and request, may be content
 570          *   language or a uselang param in the fauxrequest data may change the lang
 571          * - Skin will be based on the anonymous user, should be the wiki's default skin
 572          *
 573          * @param Title $title Title to use for the extraneous request
 574          * @param WebRequest|array $request A WebRequest or data to use for a FauxRequest
 575          * @return RequestContext
 576          */
 577         public static function newExtraneousContext( Title $title, $request = array() ) {
 578                 $context = new self;
 579                 $context->setTitle( $title );
 580                 if ( $request instanceof WebRequest ) {
 581                         $context->setRequest( $request );
 582                 } else {
 583                         $context->setRequest( new FauxRequest( $request ) );
 584                 }
 585                 $context->user = User::newFromName( '127.0.0.1', false );
 586
 587                 return $context;
 588         }
 589 }