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          * Set the WebRequest object
  68          *
  69          * @param WebRequest $r
  70          */
  71         public function setRequest( WebRequest $r ) {
  72                 $this->request = $r;
  73         }
  74
  75         /**
  76          * Get the WebRequest object
  77          *
  78          * @return WebRequest
  79          */
  80         public function getRequest() {
  81                 if ( $this->request === null ) {
  82                         global $wgRequest; # fallback to $wg till we can improve this
  83                         $this->request = $wgRequest;
  84                 }
  85                 return $this->request;
  86         }
  87
  88         /**
  89          * Set the Title object
  90          *
  91          * @param Title $t
  92          */
  93         public function setTitle( $t ) {
  94                 if ( $t !== null && !$t instanceof Title ) {
  95                         throw new MWException( __METHOD__ . " expects an instance of Title" );
  96                 }
  97                 $this->title = $t;
  98                 // Erase the WikiPage so a new one with the new title gets created.
  99                 $this->wikipage = null;
 100         }
 101
 102         /**
 103          * Get the Title object
 104          *
 105          * @return Title
 106          */
 107         public function getTitle() {
 108                 if ( $this->title === null ) {
 109                         global $wgTitle; # fallback to $wg till we can improve this
 110                         $this->title = $wgTitle;
 111                 }
 112                 return $this->title;
 113         }
 114
 115         /**
 116          * Check whether a WikiPage object can be get with getWikiPage().
 117          * Callers should expect that an exception is thrown from getWikiPage()
 118          * if this method returns false.
 119          *
 120          * @since 1.19
 121          * @return bool
 122          */
 123         public function canUseWikiPage() {
 124                 if ( $this->wikipage !== null ) {
 125                         # If there's a WikiPage object set, we can for sure get it
 126                         return true;
 127                 }
 128                 $title = $this->getTitle();
 129                 if ( $title === null ) {
 130                         # No Title, no WikiPage
 131                         return false;
 132                 } else {
 133                         # Only namespaces whose pages are stored in the database can have WikiPage
 134                         return $title->canExist();
 135                 }
 136         }
 137
 138         /**
 139          * Set the WikiPage object
 140          *
 141          * @since 1.19
 142          * @param WikiPage $p
 143          */
 144         public function setWikiPage( WikiPage $p ) {
 145                 $contextTitle = $this->getTitle();
 146                 $pageTitle = $p->getTitle();
 147                 if ( !$contextTitle || !$pageTitle->equals( $contextTitle ) ) {
 148                         $this->setTitle( $pageTitle );
 149                 }
 150                 // Defer this to the end since setTitle sets it to null.
 151                 $this->wikipage = $p;
 152         }
 153
 154         /**
 155          * Get the WikiPage object.
 156          * May throw an exception if there's no Title object set or the Title object
 157          * belongs to a special namespace that doesn't have WikiPage, so use first
 158          * canUseWikiPage() to check whether this method can be called safely.
 159          *
 160          * @since 1.19
 161          * @throws MWException
 162          * @return WikiPage
 163          */
 164         public function getWikiPage() {
 165                 if ( $this->wikipage === null ) {
 166                         $title = $this->getTitle();
 167                         if ( $title === null ) {
 168                                 throw new MWException( __METHOD__ . ' called without Title object set' );
 169                         }
 170                         $this->wikipage = WikiPage::factory( $title );
 171                 }
 172                 return $this->wikipage;
 173         }
 174
 175         /**
 176          * @param $o OutputPage
 177          */
 178         public function setOutput( OutputPage $o ) {
 179                 $this->output = $o;
 180         }
 181
 182         /**
 183          * Get the OutputPage object
 184          *
 185          * @return OutputPage
 186          */
 187         public function getOutput() {
 188                 if ( $this->output === null ) {
 189                         $this->output = new OutputPage( $this );
 190                 }
 191                 return $this->output;
 192         }
 193
 194         /**
 195          * Set the User object
 196          *
 197          * @param User $u
 198          */
 199         public function setUser( User $u ) {
 200                 $this->user = $u;
 201         }
 202
 203         /**
 204          * Get the User object
 205          *
 206          * @return User
 207          */
 208         public function getUser() {
 209                 if ( $this->user === null ) {
 210                         $this->user = User::newFromSession( $this->getRequest() );
 211                 }
 212                 return $this->user;
 213         }
 214
 215         /**
 216          * Accepts a language code and ensures it's sane. Outputs a cleaned up language
 217          * code and replaces with $wgLanguageCode if not sane.
 218          * @param string $code Language code
 219          * @return string
 220          */
 221         public static function sanitizeLangCode( $code ) {
 222                 global $wgLanguageCode;
 223
 224                 // BCP 47 - letter case MUST NOT carry meaning
 225                 $code = strtolower( $code );
 226
 227                 # Validate $code
 228                 if ( empty( $code ) || !Language::isValidCode( $code ) || ( $code === 'qqq' ) ) {
 229                         wfDebug( "Invalid user language code\n" );
 230                         $code = $wgLanguageCode;
 231                 }
 232
 233                 return $code;
 234         }
 235
 236         /**
 237          * Set the Language object
 238          *
 239          * @deprecated since 1.19 Use setLanguage instead
 240          * @param Language|string $l Language instance or language code
 241          */
 242         public function setLang( $l ) {
 243                 wfDeprecated( __METHOD__, '1.19' );
 244                 $this->setLanguage( $l );
 245         }
 246
 247         /**
 248          * Set the Language object
 249          *
 250          * @param Language|string $l Language instance or language code
 251          * @throws MWException
 252          * @since 1.19
 253          */
 254         public function setLanguage( $l ) {
 255                 if ( $l instanceof Language ) {
 256                         $this->lang = $l;
 257                 } elseif ( is_string( $l ) ) {
 258                         $l = self::sanitizeLangCode( $l );
 259                         $obj = Language::factory( $l );
 260                         $this->lang = $obj;
 261                 } else {
 262                         throw new MWException( __METHOD__ . " was passed an invalid type of data." );
 263                 }
 264         }
 265
 266         /**
 267          * @deprecated since 1.19 Use getLanguage instead
 268          * @return Language
 269          */
 270         public function getLang() {
 271                 wfDeprecated( __METHOD__, '1.19' );
 272                 return $this->getLanguage();
 273         }
 274
 275         /**
 276          * Get the Language object.
 277          * Initialization of user or request objects can depend on this.
 278          *
 279          * @return Language
 280          * @since 1.19
 281          */
 282         public function getLanguage() {
 283                 if ( isset( $this->recursion ) ) {
 284                         trigger_error( "Recursion detected in " . __METHOD__, E_USER_WARNING );
 285                         $e = new Exception;
 286                         wfDebugLog( 'recursion-guard', "Recursion detected:\n" . $e->getTraceAsString() );
 287
 288                         global $wgLanguageCode;
 289                         $code = ( $wgLanguageCode ) ? $wgLanguageCode : 'en';
 290                         $this->lang = Language::factory( $code );
 291                 } elseif ( $this->lang === null ) {
 292                         $this->recursion = true;
 293
 294                         global $wgLanguageCode, $wgContLang;
 295
 296                         $request = $this->getRequest();
 297                         $user = $this->getUser();
 298
 299                         $code = $request->getVal( 'uselang', $user->getOption( 'language' ) );
 300                         $code = self::sanitizeLangCode( $code );
 301
 302                         wfRunHooks( 'UserGetLanguageObject', array( $user, &$code, $this ) );
 303
 304                         if ( $code === $wgLanguageCode ) {
 305                                 $this->lang = $wgContLang;
 306                         } else {
 307                                 $obj = Language::factory( $code );
 308                                 $this->lang = $obj;
 309                         }
 310
 311                         unset( $this->recursion );
 312                 }
 313
 314                 return $this->lang;
 315         }
 316
 317         /**
 318          * Set the Skin object
 319          *
 320          * @param Skin $s
 321          */
 322         public function setSkin( Skin $s ) {
 323                 $this->skin = clone $s;
 324                 $this->skin->setContext( $this );
 325         }
 326
 327         /**
 328          * Get the Skin object
 329          *
 330          * @return Skin
 331          */
 332         public function getSkin() {
 333                 if ( $this->skin === null ) {
 334                         wfProfileIn( __METHOD__ . '-createskin' );
 335
 336                         $skin = null;
 337                         wfRunHooks( 'RequestContextCreateSkin', array( $this, &$skin ) );
 338
 339                         // If the hook worked try to set a skin from it
 340                         if ( $skin instanceof Skin ) {
 341                                 $this->skin = $skin;
 342                         } elseif ( is_string( $skin ) ) {
 343                                 $this->skin = Skin::newFromKey( $skin );
 344                         }
 345
 346                         // If this is still null (the hook didn't run or didn't work)
 347                         // then go through the normal processing to load a skin
 348                         if ( $this->skin === null ) {
 349                                 global $wgHiddenPrefs;
 350                                 if ( !in_array( 'skin', $wgHiddenPrefs ) ) {
 351                                         # get the user skin
 352                                         $userSkin = $this->getUser()->getOption( 'skin' );
 353                                         $userSkin = $this->getRequest()->getVal( 'useskin', $userSkin );
 354                                 } else {
 355                                         # if we're not allowing users to override, then use the default
 356                                         global $wgDefaultSkin;
 357                                         $userSkin = $wgDefaultSkin;
 358                                 }
 359
 360                                 $this->skin = Skin::newFromKey( $userSkin );
 361                         }
 362
 363                         // After all that set a context on whatever skin got created
 364                         $this->skin->setContext( $this );
 365                         wfProfileOut( __METHOD__ . '-createskin' );
 366                 }
 367                 return $this->skin;
 368         }
 369
 370         /** Helpful methods **/
 371
 372         /**
 373          * Get a Message object with context set
 374          * Parameters are the same as wfMessage()
 375          *
 376          * @return Message
 377          */
 378         public function msg() {
 379                 $args = func_get_args();
 380                 return call_user_func_array( 'wfMessage', $args )->setContext( $this );
 381         }
 382
 383         /** Static methods **/
 384
 385         /**
 386          * Get the RequestContext object associated with the main request
 387          *
 388          * @return RequestContext
 389          */
 390         public static function getMain() {
 391                 static $instance = null;
 392                 if ( $instance === null ) {
 393                         $instance = new self;
 394                 }
 395                 return $instance;
 396         }
 397
 398         /**
 399          * Export the resolved user IP, HTTP headers, user ID, and session ID.
 400          * The result will be reasonably sized to allow for serialization.
 401          *
 402          * @return Array
 403          * @since 1.21
 404          */
 405         public function exportSession() {
 406                 return array(
 407                         'ip' => $this->getRequest()->getIP(),
 408                         'headers' => $this->getRequest()->getAllHeaders(),
 409                         'sessionId' => session_id(),
 410                         'userId' => $this->getUser()->getId()
 411                 );
 412         }
 413
 414         /**
 415          * Import the resolved user IP, HTTP headers, user ID, and session ID.
 416          * This sets the current session and sets $wgUser and $wgRequest.
 417          * Once the return value falls out of scope, the old context is restored.
 418          * This function can only be called within CLI mode scripts.
 419          *
 420          * This will setup the session from the given ID. This is useful when
 421          * background scripts inherit context when acting on behalf of a user.
 422          *
 423          * @note suhosin.session.encrypt may interfere with this method.
 424          *
 425          * @param array $params Result of RequestContext::exportSession()
 426          * @return ScopedCallback
 427          * @throws MWException
 428          * @since 1.21
 429          */
 430         public static function importScopedSession( array $params ) {
 431                 if ( PHP_SAPI !== 'cli' ) {
 432                         // Don't send random private cookies or turn $wgRequest into FauxRequest
 433                         throw new MWException( "Sessions can only be imported in cli mode." );
 434                 } elseif ( !strlen( $params['sessionId'] ) ) {
 435                         throw new MWException( "No session ID was specified." );
 436                 }
 437
 438                 if ( $params['userId'] ) { // logged-in user
 439                         $user = User::newFromId( $params['userId'] );
 440                         if ( !$user ) {
 441                                 throw new MWException( "No user with ID '{$params['userId']}'." );
 442                         }
 443                 } elseif ( !IP::isValid( $params['ip'] ) ) {
 444                         throw new MWException( "Could not load user '{$params['ip']}'." );
 445                 } else { // anon user
 446                         $user = User::newFromName( $params['ip'], false );
 447                 }
 448
 449                 $importSessionFunction = function( User $user, array $params ) {
 450                         global $wgRequest, $wgUser;
 451
 452                         $context = RequestContext::getMain();
 453                         // Commit and close any current session
 454                         session_write_close(); // persist
 455                         session_id( '' ); // detach
 456                         $_SESSION = array(); // clear in-memory array
 457                         // Remove any user IP or agent information
 458                         $context->setRequest( new FauxRequest() );
 459                         $wgRequest = $context->getRequest(); // b/c
 460                         // Now that all private information is detached from the user, it should
 461                         // be safe to load the new user. If errors occur or an exception is thrown
 462                         // and caught (leaving the main context in a mixed state), there is no risk
 463                         // of the User object being attached to the wrong IP, headers, or session.
 464                         $context->setUser( $user );
 465                         $wgUser = $context->getUser(); // b/c
 466                         if ( strlen( $params['sessionId'] ) ) { // don't make a new random ID
 467                                 wfSetupSession( $params['sessionId'] ); // sets $_SESSION
 468                         }
 469                         $request = new FauxRequest( array(), false, $_SESSION );
 470                         $request->setIP( $params['ip'] );
 471                         foreach ( $params['headers'] as $name => $value ) {
 472                                 $request->setHeader( $name, $value );
 473                         }
 474                         // Set the current context to use the new WebRequest
 475                         $context->setRequest( $request );
 476                         $wgRequest = $context->getRequest(); // b/c
 477                 };
 478
 479                 // Stash the old session and load in the new one
 480                 $oUser = self::getMain()->getUser();
 481                 $oParams = self::getMain()->exportSession();
 482                 $importSessionFunction( $user, $params );
 483
 484                 // Set callback to save and close the new session and reload the old one
 485                 return new ScopedCallback( function() use ( $importSessionFunction, $oUser, $oParams ) {
 486                         $importSessionFunction( $oUser, $oParams );
 487                 } );
 488         }
 489
 490         /**
 491          * Create a new extraneous context. The context is filled with information
 492          * external to the current session.
 493          * - Title is specified by argument
 494          * - Request is a FauxRequest, or a FauxRequest can be specified by argument
 495          * - User is an anonymous user, for separation IPv4 localhost is used
 496          * - Language will be based on the anonymous user and request, may be content
 497          *   language or a uselang param in the fauxrequest data may change the lang
 498          * - Skin will be based on the anonymous user, should be the wiki's default skin
 499          *
 500          * @param Title $title Title to use for the extraneous request
 501          * @param WebRequest|array $request A WebRequest or data to use for a FauxRequest
 502          * @return RequestContext
 503          */
 504         public static function newExtraneousContext( Title $title, $request = array() ) {
 505                 $context = new self;
 506                 $context->setTitle( $title );
 507                 if ( $request instanceof WebRequest ) {
 508                         $context->setRequest( $request );
 509                 } else {
 510                         $context->setRequest( new FauxRequest( $request ) );
 511                 }
 512                 $context->user = User::newFromName( '127.0.0.1', false );
 513                 return $context;
 514         }
 515 }