includes/context/RequestContext.php

   1 <?php
   2 /**
   3  * Request-dependant objects containers.
   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 $t
 127          */
 128         public function setTitle( Title $t ) {
 129                 $this->title = $t;
 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                 }
 144
 145                 return $this->title;
 146         }
 147
 148         /**
 149          * Check whether a WikiPage object can be get with getWikiPage().
 150          * Callers should expect that an exception is thrown from getWikiPage()
 151          * if this method returns false.
 152          *
 153          * @since 1.19
 154          * @return bool
 155          */
 156         public function canUseWikiPage() {
 157                 if ( $this->wikipage ) {
 158                         // If there's a WikiPage object set, we can for sure get it
 159                         return true;
 160                 }
 161                 // Only pages with legitimate titles can have WikiPages.
 162                 // That usually means pages in non-virtual namespaces.
 163                 $title = $this->getTitle();
 164                 return $title ? $title->canExist() : false;
 165         }
 166
 167         /**
 168          * Set the WikiPage object
 169          *
 170          * @since 1.19
 171          * @param WikiPage $p
 172          */
 173         public function setWikiPage( WikiPage $p ) {
 174                 $contextTitle = $this->getTitle();
 175                 $pageTitle = $p->getTitle();
 176                 if ( !$contextTitle || !$pageTitle->equals( $contextTitle ) ) {
 177                         $this->setTitle( $pageTitle );
 178                 }
 179                 // Defer this to the end since setTitle sets it to null.
 180                 $this->wikipage = $p;
 181         }
 182
 183         /**
 184          * Get the WikiPage object.
 185          * May throw an exception if there's no Title object set or the Title object
 186          * belongs to a special namespace that doesn't have WikiPage, so use first
 187          * canUseWikiPage() to check whether this method can be called safely.
 188          *
 189          * @since 1.19
 190          * @throws MWException
 191          * @return WikiPage
 192          */
 193         public function getWikiPage() {
 194                 if ( $this->wikipage === null ) {
 195                         $title = $this->getTitle();
 196                         if ( $title === null ) {
 197                                 throw new MWException( __METHOD__ . ' called without Title object set' );
 198                         }
 199                         $this->wikipage = WikiPage::factory( $title );
 200                 }
 201
 202                 return $this->wikipage;
 203         }
 204
 205         /**
 206          * @param OutputPage $o
 207          */
 208         public function setOutput( OutputPage $o ) {
 209                 $this->output = $o;
 210         }
 211
 212         /**
 213          * Get the OutputPage object
 214          *
 215          * @return OutputPage
 216          */
 217         public function getOutput() {
 218                 if ( $this->output === null ) {
 219                         $this->output = new OutputPage( $this );
 220                 }
 221
 222                 return $this->output;
 223         }
 224
 225         /**
 226          * Set the User object
 227          *
 228          * @param User $u
 229          */
 230         public function setUser( User $u ) {
 231                 $this->user = $u;
 232         }
 233
 234         /**
 235          * Get the User object
 236          *
 237          * @return User
 238          */
 239         public function getUser() {
 240                 if ( $this->user === null ) {
 241                         $this->user = User::newFromSession( $this->getRequest() );
 242                 }
 243
 244                 return $this->user;
 245         }
 246
 247         /**
 248          * Accepts a language code and ensures it's sane. Outputs a cleaned up language
 249          * code and replaces with $wgLanguageCode if not sane.
 250          * @param string $code Language code
 251          * @return string
 252          */
 253         public static function sanitizeLangCode( $code ) {
 254                 global $wgLanguageCode;
 255
 256                 // BCP 47 - letter case MUST NOT carry meaning
 257                 $code = strtolower( $code );
 258
 259                 # Validate $code
 260                 if ( !$code || !Language::isValidCode( $code ) || $code === 'qqq' ) {
 261                         wfDebug( "Invalid user language code\n" );
 262                         $code = $wgLanguageCode;
 263                 }
 264
 265                 return $code;
 266         }
 267
 268         /**
 269          * Set the Language object
 270          *
 271          * @param Language|string $l Language instance or language code
 272          * @throws MWException
 273          * @since 1.19
 274          */
 275         public function setLanguage( $l ) {
 276                 if ( $l instanceof Language ) {
 277                         $this->lang = $l;
 278                 } elseif ( is_string( $l ) ) {
 279                         $l = self::sanitizeLangCode( $l );
 280                         $obj = Language::factory( $l );
 281                         $this->lang = $obj;
 282                 } else {
 283                         throw new MWException( __METHOD__ . " was passed an invalid type of data." );
 284                 }
 285         }
 286
 287         /**
 288          * Get the Language object.
 289          * Initialization of user or request objects can depend on this.
 290          *
 291          * @return Language
 292          * @since 1.19
 293          */
 294         public function getLanguage() {
 295                 if ( isset( $this->recursion ) ) {
 296                         trigger_error( "Recursion detected in " . __METHOD__, E_USER_WARNING );
 297                         $e = new Exception;
 298                         wfDebugLog( 'recursion-guard', "Recursion detected:\n" . $e->getTraceAsString() );
 299
 300                         global $wgLanguageCode;
 301                         $code = ( $wgLanguageCode ) ? $wgLanguageCode : 'en';
 302                         $this->lang = Language::factory( $code );
 303                 } elseif ( $this->lang === null ) {
 304                         $this->recursion = true;
 305
 306                         global $wgLanguageCode, $wgContLang;
 307
 308                         try {
 309                                 $request = $this->getRequest();
 310                                 $user = $this->getUser();
 311
 312                                 $code = $request->getVal( 'uselang', $user->getOption( 'language' ) );
 313                                 $code = self::sanitizeLangCode( $code );
 314
 315                                 wfRunHooks( 'UserGetLanguageObject', array( $user, &$code, $this ) );
 316
 317                                 if ( $code === $wgLanguageCode ) {
 318                                         $this->lang = $wgContLang;
 319                                 } else {
 320                                         $obj = Language::factory( $code );
 321                                         $this->lang = $obj;
 322                                 }
 323
 324                                 unset( $this->recursion );
 325                         }
 326                         catch ( Exception $ex ) {
 327                                 unset( $this->recursion );
 328                                 throw $ex;
 329                         }
 330                 }
 331
 332                 return $this->lang;
 333         }
 334
 335         /**
 336          * Set the Skin object
 337          *
 338          * @param Skin $s
 339          */
 340         public function setSkin( Skin $s ) {
 341                 $this->skin = clone $s;
 342                 $this->skin->setContext( $this );
 343         }
 344
 345         /**
 346          * Get the Skin object
 347          *
 348          * @return Skin
 349          */
 350         public function getSkin() {
 351                 if ( $this->skin === null ) {
 352                         wfProfileIn( __METHOD__ . '-createskin' );
 353
 354                         $skin = null;
 355                         wfRunHooks( 'RequestContextCreateSkin', array( $this, &$skin ) );
 356
 357                         // If the hook worked try to set a skin from it
 358                         if ( $skin instanceof Skin ) {
 359                                 $this->skin = $skin;
 360                         } elseif ( is_string( $skin ) ) {
 361                                 $this->skin = Skin::newFromKey( $skin );
 362                         }
 363
 364                         // If this is still null (the hook didn't run or didn't work)
 365                         // then go through the normal processing to load a skin
 366                         if ( $this->skin === null ) {
 367                                 global $wgHiddenPrefs;
 368                                 if ( !in_array( 'skin', $wgHiddenPrefs ) ) {
 369                                         # get the user skin
 370                                         $userSkin = $this->getUser()->getOption( 'skin' );
 371                                         $userSkin = $this->getRequest()->getVal( 'useskin', $userSkin );
 372                                 } else {
 373                                         # if we're not allowing users to override, then use the default
 374                                         global $wgDefaultSkin;
 375                                         $userSkin = $wgDefaultSkin;
 376                                 }
 377
 378                                 $this->skin = Skin::newFromKey( $userSkin );
 379                         }
 380
 381                         // After all that set a context on whatever skin got created
 382                         $this->skin->setContext( $this );
 383                         wfProfileOut( __METHOD__ . '-createskin' );
 384                 }
 385
 386                 return $this->skin;
 387         }
 388
 389         /** Helpful methods **/
 390
 391         /**
 392          * Get a Message object with context set
 393          * Parameters are the same as wfMessage()
 394          *
 395          * @return Message
 396          */
 397         public function msg() {
 398                 $args = func_get_args();
 399
 400                 return call_user_func_array( 'wfMessage', $args )->setContext( $this );
 401         }
 402
 403         /** Static methods **/
 404
 405         /**
 406          * Get the RequestContext object associated with the main request
 407          *
 408          * @return RequestContext
 409          */
 410         public static function getMain() {
 411                 if ( self::$instance === null ) {
 412                         self::$instance = new self;
 413                 }
 414
 415                 return self::$instance;
 416         }
 417
 418         /**
 419          * Resets singleton returned by getMain(). Should be called only from unit tests.
 420          */
 421         public static function resetMain() {
 422                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 423                         throw new MWException( __METHOD__ . '() should be called only from unit tests!' );
 424                 }
 425                 self::$instance = null;
 426         }
 427
 428         /**
 429          * Export the resolved user IP, HTTP headers, user ID, and session ID.
 430          * The result will be reasonably sized to allow for serialization.
 431          *
 432          * @return array
 433          * @since 1.21
 434          */
 435         public function exportSession() {
 436                 return array(
 437                         'ip' => $this->getRequest()->getIP(),
 438                         'headers' => $this->getRequest()->getAllHeaders(),
 439                         'sessionId' => session_id(),
 440                         'userId' => $this->getUser()->getId()
 441                 );
 442         }
 443
 444         /**
 445          * Import the resolved user IP, HTTP headers, user ID, and session ID.
 446          * This sets the current session and sets $wgUser and $wgRequest.
 447          * Once the return value falls out of scope, the old context is restored.
 448          * This function can only be called within CLI mode scripts.
 449          *
 450          * This will setup the session from the given ID. This is useful when
 451          * background scripts inherit context when acting on behalf of a user.
 452          *
 453          * @note suhosin.session.encrypt may interfere with this method.
 454          *
 455          * @param array $params Result of RequestContext::exportSession()
 456          * @return ScopedCallback
 457          * @throws MWException
 458          * @since 1.21
 459          */
 460         public static function importScopedSession( array $params ) {
 461                 if ( PHP_SAPI !== 'cli' ) {
 462                         // Don't send random private cookies or turn $wgRequest into FauxRequest
 463                         throw new MWException( "Sessions can only be imported in cli mode." );
 464                 } elseif ( !strlen( $params['sessionId'] ) ) {
 465                         throw new MWException( "No session ID was specified." );
 466                 }
 467
 468                 if ( $params['userId'] ) { // logged-in user
 469                         $user = User::newFromId( $params['userId'] );
 470                         $user->load();
 471                         if ( !$user->getId() ) {
 472                                 throw new MWException( "No user with ID '{$params['userId']}'." );
 473                         }
 474                 } elseif ( !IP::isValid( $params['ip'] ) ) {
 475                         throw new MWException( "Could not load user '{$params['ip']}'." );
 476                 } else { // anon user
 477                         $user = User::newFromName( $params['ip'], false );
 478                 }
 479
 480                 $importSessionFunction = function ( User $user, array $params ) {
 481                         global $wgRequest, $wgUser;
 482
 483                         $context = RequestContext::getMain();
 484                         // Commit and close any current session
 485                         session_write_close(); // persist
 486                         session_id( '' ); // detach
 487                         $_SESSION = array(); // clear in-memory array
 488                         // Remove any user IP or agent information
 489                         $context->setRequest( new FauxRequest() );
 490                         $wgRequest = $context->getRequest(); // b/c
 491                         // Now that all private information is detached from the user, it should
 492                         // be safe to load the new user. If errors occur or an exception is thrown
 493                         // and caught (leaving the main context in a mixed state), there is no risk
 494                         // of the User object being attached to the wrong IP, headers, or session.
 495                         $context->setUser( $user );
 496                         $wgUser = $context->getUser(); // b/c
 497                         if ( strlen( $params['sessionId'] ) ) { // don't make a new random ID
 498                                 wfSetupSession( $params['sessionId'] ); // sets $_SESSION
 499                         }
 500                         $request = new FauxRequest( array(), false, $_SESSION );
 501                         $request->setIP( $params['ip'] );
 502                         foreach ( $params['headers'] as $name => $value ) {
 503                                 $request->setHeader( $name, $value );
 504                         }
 505                         // Set the current context to use the new WebRequest
 506                         $context->setRequest( $request );
 507                         $wgRequest = $context->getRequest(); // b/c
 508                 };
 509
 510                 // Stash the old session and load in the new one
 511                 $oUser = self::getMain()->getUser();
 512                 $oParams = self::getMain()->exportSession();
 513                 $importSessionFunction( $user, $params );
 514
 515                 // Set callback to save and close the new session and reload the old one
 516                 return new ScopedCallback( function () use ( $importSessionFunction, $oUser, $oParams ) {
 517                         $importSessionFunction( $oUser, $oParams );
 518                 } );
 519         }
 520
 521         /**
 522          * Create a new extraneous context. The context is filled with information
 523          * external to the current session.
 524          * - Title is specified by argument
 525          * - Request is a FauxRequest, or a FauxRequest can be specified by argument
 526          * - User is an anonymous user, for separation IPv4 localhost is used
 527          * - Language will be based on the anonymous user and request, may be content
 528          *   language or a uselang param in the fauxrequest data may change the lang
 529          * - Skin will be based on the anonymous user, should be the wiki's default skin
 530          *
 531          * @param Title $title Title to use for the extraneous request
 532          * @param WebRequest|array $request A WebRequest or data to use for a FauxRequest
 533          * @return RequestContext
 534          */
 535         public static function newExtraneousContext( Title $title, $request = array() ) {
 536                 $context = new self;
 537                 $context->setTitle( $title );
 538                 if ( $request instanceof WebRequest ) {
 539                         $context->setRequest( $request );
 540                 } else {
 541                         $context->setRequest( new FauxRequest( $request ) );
 542                 }
 543                 $context->user = User::newFromName( '127.0.0.1', false );
 544
 545                 return $context;
 546         }
 547 }