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          * Set the Config object
  73          *
  74          * @param Config $c
  75          */
  76         public function setConfig( Config $c ) {
  77                 $this->config = $c;
  78         }
  79
  80         /**
  81          * Get the Config object
  82          *
  83          * @return Config
  84          */
  85         public function getConfig() {
  86                 if ( $this->config === null ) {
  87                         // @todo In the future, we could move this to WebStart.php so
  88                         // the Config object is ready for when initialization happens
  89                         $this->config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
  90                 }
  91
  92                 return $this->config;
  93         }
  94
  95         /**
  96          * Set the WebRequest object
  97          *
  98          * @param WebRequest $r
  99          */
 100         public function setRequest( WebRequest $r ) {
 101                 $this->request = $r;
 102         }
 103
 104         /**
 105          * Get the WebRequest object
 106          *
 107          * @return WebRequest
 108          */
 109         public function getRequest() {
 110                 if ( $this->request === null ) {
 111                         global $wgRequest; # fallback to $wg till we can improve this
 112                         $this->request = $wgRequest;
 113                 }
 114
 115                 return $this->request;
 116         }
 117
 118         /**
 119          * Set the Title object
 120          *
 121          * @param Title $t
 122          * @throws MWException
 123          */
 124         public function setTitle( $t ) {
 125                 if ( $t !== null && !$t instanceof Title ) {
 126                         throw new MWException( __METHOD__ . " expects an instance of Title" );
 127                 }
 128                 $this->title = $t;
 129                 // Erase the WikiPage so a new one with the new title gets created.
 130                 $this->wikipage = null;
 131         }
 132
 133         /**
 134          * Get the Title object
 135          *
 136          * @return Title|null
 137          */
 138         public function getTitle() {
 139                 if ( $this->title === null ) {
 140                         global $wgTitle; # fallback to $wg till we can improve this
 141                         $this->title = $wgTitle;
 142                 }
 143
 144                 return $this->title;
 145         }
 146
 147         /**
 148          * Check whether a WikiPage object can be get with getWikiPage().
 149          * Callers should expect that an exception is thrown from getWikiPage()
 150          * if this method returns false.
 151          *
 152          * @since 1.19
 153          * @return bool
 154          */
 155         public function canUseWikiPage() {
 156                 if ( $this->wikipage !== null ) {
 157                         # If there's a WikiPage object set, we can for sure get it
 158                         return true;
 159                 }
 160                 $title = $this->getTitle();
 161                 if ( $title === null ) {
 162                         # No Title, no WikiPage
 163                         return false;
 164                 } else {
 165                         # Only namespaces whose pages are stored in the database can have WikiPage
 166                         return $title->canExist();
 167                 }
 168         }
 169
 170         /**
 171          * Set the WikiPage object
 172          *
 173          * @since 1.19
 174          * @param WikiPage $p
 175          */
 176         public function setWikiPage( WikiPage $p ) {
 177                 $contextTitle = $this->getTitle();
 178                 $pageTitle = $p->getTitle();
 179                 if ( !$contextTitle || !$pageTitle->equals( $contextTitle ) ) {
 180                         $this->setTitle( $pageTitle );
 181                 }
 182                 // Defer this to the end since setTitle sets it to null.
 183                 $this->wikipage = $p;
 184         }
 185
 186         /**
 187          * Get the WikiPage object.
 188          * May throw an exception if there's no Title object set or the Title object
 189          * belongs to a special namespace that doesn't have WikiPage, so use first
 190          * canUseWikiPage() to check whether this method can be called safely.
 191          *
 192          * @since 1.19
 193          * @throws MWException
 194          * @return WikiPage
 195          */
 196         public function getWikiPage() {
 197                 if ( $this->wikipage === null ) {
 198                         $title = $this->getTitle();
 199                         if ( $title === null ) {
 200                                 throw new MWException( __METHOD__ . ' called without Title object set' );
 201                         }
 202                         $this->wikipage = WikiPage::factory( $title );
 203                 }
 204
 205                 return $this->wikipage;
 206         }
 207
 208         /**
 209          * @param OutputPage $o
 210          */
 211         public function setOutput( OutputPage $o ) {
 212                 $this->output = $o;
 213         }
 214
 215         /**
 216          * Get the OutputPage object
 217          *
 218          * @return OutputPage
 219          */
 220         public function getOutput() {
 221                 if ( $this->output === null ) {
 222                         $this->output = new OutputPage( $this );
 223                 }
 224
 225                 return $this->output;
 226         }
 227
 228         /**
 229          * Set the User object
 230          *
 231          * @param User $u
 232          */
 233         public function setUser( User $u ) {
 234                 $this->user = $u;
 235         }
 236
 237         /**
 238          * Get the User object
 239          *
 240          * @return User
 241          */
 242         public function getUser() {
 243                 if ( $this->user === null ) {
 244                         $this->user = User::newFromSession( $this->getRequest() );
 245                 }
 246
 247                 return $this->user;
 248         }
 249
 250         /**
 251          * Accepts a language code and ensures it's sane. Outputs a cleaned up language
 252          * code and replaces with $wgLanguageCode if not sane.
 253          * @param string $code Language code
 254          * @return string
 255          */
 256         public static function sanitizeLangCode( $code ) {
 257                 global $wgLanguageCode;
 258
 259                 // BCP 47 - letter case MUST NOT carry meaning
 260                 $code = strtolower( $code );
 261
 262                 # Validate $code
 263                 if ( empty( $code ) || !Language::isValidCode( $code ) || ( $code === 'qqq' ) ) {
 264                         wfDebug( "Invalid user language code\n" );
 265                         $code = $wgLanguageCode;
 266                 }
 267
 268                 return $code;
 269         }
 270
 271         /**
 272          * Set the Language object
 273          *
 274          * @param Language|string $l Language instance or language code
 275          * @throws MWException
 276          * @since 1.19
 277          */
 278         public function setLanguage( $l ) {
 279                 if ( $l instanceof Language ) {
 280                         $this->lang = $l;
 281                 } elseif ( is_string( $l ) ) {
 282                         $l = self::sanitizeLangCode( $l );
 283                         $obj = Language::factory( $l );
 284                         $this->lang = $obj;
 285                 } else {
 286                         throw new MWException( __METHOD__ . " was passed an invalid type of data." );
 287                 }
 288         }
 289
 290         /**
 291          * Get the Language object.
 292          * Initialization of user or request objects can depend on this.
 293          *
 294          * @return Language
 295          * @since 1.19
 296          */
 297         public function getLanguage() {
 298                 if ( isset( $this->recursion ) ) {
 299                         trigger_error( "Recursion detected in " . __METHOD__, E_USER_WARNING );
 300                         $e = new Exception;
 301                         wfDebugLog( 'recursion-guard', "Recursion detected:\n" . $e->getTraceAsString() );
 302
 303                         global $wgLanguageCode;
 304                         $code = ( $wgLanguageCode ) ? $wgLanguageCode : 'en';
 305                         $this->lang = Language::factory( $code );
 306                 } elseif ( $this->lang === null ) {
 307                         $this->recursion = true;
 308
 309                         global $wgLanguageCode, $wgContLang;
 310
 311                         $request = $this->getRequest();
 312                         $user = $this->getUser();
 313
 314                         $code = $request->getVal( 'uselang', $user->getOption( 'language' ) );
 315                         $code = self::sanitizeLangCode( $code );
 316
 317                         wfRunHooks( 'UserGetLanguageObject', array( $user, &$code, $this ) );
 318
 319                         if ( $code === $wgLanguageCode ) {
 320                                 $this->lang = $wgContLang;
 321                         } else {
 322                                 $obj = Language::factory( $code );
 323                                 $this->lang = $obj;
 324                         }
 325
 326                         unset( $this->recursion );
 327                 }
 328
 329                 return $this->lang;
 330         }
 331
 332         /**
 333          * Set the Skin object
 334          *
 335          * @param Skin $s
 336          */
 337         public function setSkin( Skin $s ) {
 338                 $this->skin = clone $s;
 339                 $this->skin->setContext( $this );
 340         }
 341
 342         /**
 343          * Get the Skin object
 344          *
 345          * @return Skin
 346          */
 347         public function getSkin() {
 348                 if ( $this->skin === null ) {
 349                         wfProfileIn( __METHOD__ . '-createskin' );
 350
 351                         $skin = null;
 352                         wfRunHooks( 'RequestContextCreateSkin', array( $this, &$skin ) );
 353
 354                         // If the hook worked try to set a skin from it
 355                         if ( $skin instanceof Skin ) {
 356                                 $this->skin = $skin;
 357                         } elseif ( is_string( $skin ) ) {
 358                                 $this->skin = Skin::newFromKey( $skin );
 359                         }
 360
 361                         // If this is still null (the hook didn't run or didn't work)
 362                         // then go through the normal processing to load a skin
 363                         if ( $this->skin === null ) {
 364                                 global $wgHiddenPrefs;
 365                                 if ( !in_array( 'skin', $wgHiddenPrefs ) ) {
 366                                         # get the user skin
 367                                         $userSkin = $this->getUser()->getOption( 'skin' );
 368                                         $userSkin = $this->getRequest()->getVal( 'useskin', $userSkin );
 369                                 } else {
 370                                         # if we're not allowing users to override, then use the default
 371                                         global $wgDefaultSkin;
 372                                         $userSkin = $wgDefaultSkin;
 373                                 }
 374
 375                                 $this->skin = Skin::newFromKey( $userSkin );
 376                         }
 377
 378                         // After all that set a context on whatever skin got created
 379                         $this->skin->setContext( $this );
 380                         wfProfileOut( __METHOD__ . '-createskin' );
 381                 }
 382
 383                 return $this->skin;
 384         }
 385
 386         /** Helpful methods **/
 387
 388         /**
 389          * Get a Message object with context set
 390          * Parameters are the same as wfMessage()
 391          *
 392          * @return Message
 393          */
 394         public function msg() {
 395                 $args = func_get_args();
 396
 397                 return call_user_func_array( 'wfMessage', $args )->setContext( $this );
 398         }
 399
 400         /** Static methods **/
 401
 402         /**
 403          * Get the RequestContext object associated with the main request
 404          *
 405          * @return RequestContext
 406          */
 407         public static function getMain() {
 408                 static $instance = null;
 409                 if ( $instance === null ) {
 410                         $instance = new self;
 411                 }
 412
 413                 return $instance;
 414         }
 415
 416         /**
 417          * Export the resolved user IP, HTTP headers, user ID, and session ID.
 418          * The result will be reasonably sized to allow for serialization.
 419          *
 420          * @return array
 421          * @since 1.21
 422          */
 423         public function exportSession() {
 424                 return array(
 425                         'ip' => $this->getRequest()->getIP(),
 426                         'headers' => $this->getRequest()->getAllHeaders(),
 427                         'sessionId' => session_id(),
 428                         'userId' => $this->getUser()->getId()
 429                 );
 430         }
 431
 432         /**
 433          * Import the resolved user IP, HTTP headers, user ID, and session ID.
 434          * This sets the current session and sets $wgUser and $wgRequest.
 435          * Once the return value falls out of scope, the old context is restored.
 436          * This function can only be called within CLI mode scripts.
 437          *
 438          * This will setup the session from the given ID. This is useful when
 439          * background scripts inherit context when acting on behalf of a user.
 440          *
 441          * @note suhosin.session.encrypt may interfere with this method.
 442          *
 443          * @param array $params Result of RequestContext::exportSession()
 444          * @return ScopedCallback
 445          * @throws MWException
 446          * @since 1.21
 447          */
 448         public static function importScopedSession( array $params ) {
 449                 if ( PHP_SAPI !== 'cli' ) {
 450                         // Don't send random private cookies or turn $wgRequest into FauxRequest
 451                         throw new MWException( "Sessions can only be imported in cli mode." );
 452                 } elseif ( !strlen( $params['sessionId'] ) ) {
 453                         throw new MWException( "No session ID was specified." );
 454                 }
 455
 456                 if ( $params['userId'] ) { // logged-in user
 457                         $user = User::newFromId( $params['userId'] );
 458                         if ( !$user ) {
 459                                 throw new MWException( "No user with ID '{$params['userId']}'." );
 460                         }
 461                 } elseif ( !IP::isValid( $params['ip'] ) ) {
 462                         throw new MWException( "Could not load user '{$params['ip']}'." );
 463                 } else { // anon user
 464                         $user = User::newFromName( $params['ip'], false );
 465                 }
 466
 467                 $importSessionFunction = function ( User $user, array $params ) {
 468                         global $wgRequest, $wgUser;
 469
 470                         $context = RequestContext::getMain();
 471                         // Commit and close any current session
 472                         session_write_close(); // persist
 473                         session_id( '' ); // detach
 474                         $_SESSION = array(); // clear in-memory array
 475                         // Remove any user IP or agent information
 476                         $context->setRequest( new FauxRequest() );
 477                         $wgRequest = $context->getRequest(); // b/c
 478                         // Now that all private information is detached from the user, it should
 479                         // be safe to load the new user. If errors occur or an exception is thrown
 480                         // and caught (leaving the main context in a mixed state), there is no risk
 481                         // of the User object being attached to the wrong IP, headers, or session.
 482                         $context->setUser( $user );
 483                         $wgUser = $context->getUser(); // b/c
 484                         if ( strlen( $params['sessionId'] ) ) { // don't make a new random ID
 485                                 wfSetupSession( $params['sessionId'] ); // sets $_SESSION
 486                         }
 487                         $request = new FauxRequest( array(), false, $_SESSION );
 488                         $request->setIP( $params['ip'] );
 489                         foreach ( $params['headers'] as $name => $value ) {
 490                                 $request->setHeader( $name, $value );
 491                         }
 492                         // Set the current context to use the new WebRequest
 493                         $context->setRequest( $request );
 494                         $wgRequest = $context->getRequest(); // b/c
 495                 };
 496
 497                 // Stash the old session and load in the new one
 498                 $oUser = self::getMain()->getUser();
 499                 $oParams = self::getMain()->exportSession();
 500                 $importSessionFunction( $user, $params );
 501
 502                 // Set callback to save and close the new session and reload the old one
 503                 return new ScopedCallback( function () use ( $importSessionFunction, $oUser, $oParams ) {
 504                         $importSessionFunction( $oUser, $oParams );
 505                 } );
 506         }
 507
 508         /**
 509          * Create a new extraneous context. The context is filled with information
 510          * external to the current session.
 511          * - Title is specified by argument
 512          * - Request is a FauxRequest, or a FauxRequest can be specified by argument
 513          * - User is an anonymous user, for separation IPv4 localhost is used
 514          * - Language will be based on the anonymous user and request, may be content
 515          *   language or a uselang param in the fauxrequest data may change the lang
 516          * - Skin will be based on the anonymous user, should be the wiki's default skin
 517          *
 518          * @param Title $title Title to use for the extraneous request
 519          * @param WebRequest|array $request A WebRequest or data to use for a FauxRequest
 520          * @return RequestContext
 521          */
 522         public static function newExtraneousContext( Title $title, $request = array() ) {
 523                 $context = new self;
 524                 $context->setTitle( $title );
 525                 if ( $request instanceof WebRequest ) {
 526                         $context->setRequest( $request );
 527                 } else {
 528                         $context->setRequest( new FauxRequest( $request ) );
 529                 }
 530                 $context->user = User::newFromName( '127.0.0.1', false );
 531
 532                 return $context;
 533         }
 534 }