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, MutableContext {
  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 \Liuggio\StatsdClient\Factory\StatsdDataFactory
  66          */
  67         private $stats;
  68
  69         /**
  70          * @var Config
  71          */
  72         private $config;
  73
  74         /**
  75          * @var RequestContext
  76          */
  77         private static $instance = null;
  78
  79         /**
  80          * Set the Config object
  81          *
  82          * @param Config $c
  83          */
  84         public function setConfig( Config $c ) {
  85                 $this->config = $c;
  86         }
  87
  88         /**
  89          * Get the Config object
  90          *
  91          * @return Config
  92          */
  93         public function getConfig() {
  94                 if ( $this->config === null ) {
  95                         // @todo In the future, we could move this to WebStart.php so
  96                         // the Config object is ready for when initialization happens
  97                         $this->config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
  98                 }
  99
 100                 return $this->config;
 101         }
 102
 103         /**
 104          * Set the WebRequest object
 105          *
 106          * @param WebRequest $r
 107          */
 108         public function setRequest( WebRequest $r ) {
 109                 $this->request = $r;
 110         }
 111
 112         /**
 113          * Get the WebRequest object
 114          *
 115          * @return WebRequest
 116          */
 117         public function getRequest() {
 118                 if ( $this->request === null ) {
 119                         global $wgRequest; # fallback to $wg till we can improve this
 120                         $this->request = $wgRequest;
 121                 }
 122
 123                 return $this->request;
 124         }
 125
 126         /**
 127          * Get the Stats object
 128          *
 129          * @return BufferingStatsdDataFactory
 130          */
 131         public function getStats() {
 132                 if ( $this->stats === null ) {
 133                         $config = $this->getConfig();
 134                         $prefix = $config->get( 'StatsdMetricPrefix' )
 135                                 ? rtrim( $config->get( 'StatsdMetricPrefix' ), '.' )
 136                                 : 'MediaWiki';
 137                         $this->stats = new BufferingStatsdDataFactory( $prefix );
 138                 }
 139                 return $this->stats;
 140         }
 141
 142         /**
 143          * Set the Title object
 144          *
 145          * @param Title $title
 146          */
 147         public function setTitle( Title $title ) {
 148                 $this->title = $title;
 149                 // Erase the WikiPage so a new one with the new title gets created.
 150                 $this->wikipage = null;
 151         }
 152
 153         /**
 154          * Get the Title object
 155          *
 156          * @return Title|null
 157          */
 158         public function getTitle() {
 159                 if ( $this->title === null ) {
 160                         global $wgTitle; # fallback to $wg till we can improve this
 161                         $this->title = $wgTitle;
 162                         wfDebugLog(
 163                                 'GlobalTitleFail',
 164                                 __METHOD__ . ' called by ' . wfGetAllCallers( 5 ) . ' with no title set.'
 165                         );
 166                 }
 167
 168                 return $this->title;
 169         }
 170
 171         /**
 172          * Check, if a Title object is set
 173          *
 174          * @since 1.25
 175          * @return bool
 176          */
 177         public function hasTitle() {
 178                 return $this->title !== null;
 179         }
 180
 181         /**
 182          * Check whether a WikiPage object can be get with getWikiPage().
 183          * Callers should expect that an exception is thrown from getWikiPage()
 184          * if this method returns false.
 185          *
 186          * @since 1.19
 187          * @return bool
 188          */
 189         public function canUseWikiPage() {
 190                 if ( $this->wikipage ) {
 191                         // If there's a WikiPage object set, we can for sure get it
 192                         return true;
 193                 }
 194                 // Only pages with legitimate titles can have WikiPages.
 195                 // That usually means pages in non-virtual namespaces.
 196                 $title = $this->getTitle();
 197                 return $title ? $title->canExist() : false;
 198         }
 199
 200         /**
 201          * Set the WikiPage object
 202          *
 203          * @since 1.19
 204          * @param WikiPage $p
 205          */
 206         public function setWikiPage( WikiPage $p ) {
 207                 $pageTitle = $p->getTitle();
 208                 if ( !$this->hasTitle() || !$pageTitle->equals( $this->getTitle() ) ) {
 209                         $this->setTitle( $pageTitle );
 210                 }
 211                 // Defer this to the end since setTitle sets it to null.
 212                 $this->wikipage = $p;
 213         }
 214
 215         /**
 216          * Get the WikiPage object.
 217          * May throw an exception if there's no Title object set or the Title object
 218          * belongs to a special namespace that doesn't have WikiPage, so use first
 219          * canUseWikiPage() to check whether this method can be called safely.
 220          *
 221          * @since 1.19
 222          * @throws MWException
 223          * @return WikiPage
 224          */
 225         public function getWikiPage() {
 226                 if ( $this->wikipage === null ) {
 227                         $title = $this->getTitle();
 228                         if ( $title === null ) {
 229                                 throw new MWException( __METHOD__ . ' called without Title object set' );
 230                         }
 231                         $this->wikipage = WikiPage::factory( $title );
 232                 }
 233
 234                 return $this->wikipage;
 235         }
 236
 237         /**
 238          * @param OutputPage $o
 239          */
 240         public function setOutput( OutputPage $o ) {
 241                 $this->output = $o;
 242         }
 243
 244         /**
 245          * Get the OutputPage object
 246          *
 247          * @return OutputPage
 248          */
 249         public function getOutput() {
 250                 if ( $this->output === null ) {
 251                         $this->output = new OutputPage( $this );
 252                 }
 253
 254                 return $this->output;
 255         }
 256
 257         /**
 258          * Set the User object
 259          *
 260          * @param User $u
 261          */
 262         public function setUser( User $u ) {
 263                 $this->user = $u;
 264         }
 265
 266         /**
 267          * Get the User object
 268          *
 269          * @return User
 270          */
 271         public function getUser() {
 272                 if ( $this->user === null ) {
 273                         $this->user = User::newFromSession( $this->getRequest() );
 274                 }
 275
 276                 return $this->user;
 277         }
 278
 279         /**
 280          * Accepts a language code and ensures it's sane. Outputs a cleaned up language
 281          * code and replaces with $wgLanguageCode if not sane.
 282          * @param string $code Language code
 283          * @return string
 284          */
 285         public static function sanitizeLangCode( $code ) {
 286                 global $wgLanguageCode;
 287
 288                 // BCP 47 - letter case MUST NOT carry meaning
 289                 $code = strtolower( $code );
 290
 291                 # Validate $code
 292                 if ( !$code || !Language::isValidCode( $code ) || $code === 'qqq' ) {
 293                         wfDebug( "Invalid user language code\n" );
 294                         $code = $wgLanguageCode;
 295                 }
 296
 297                 return $code;
 298         }
 299
 300         /**
 301          * Set the Language object
 302          *
 303          * @param Language|string $l Language instance or language code
 304          * @throws MWException
 305          * @since 1.19
 306          */
 307         public function setLanguage( $l ) {
 308                 if ( $l instanceof Language ) {
 309                         $this->lang = $l;
 310                 } elseif ( is_string( $l ) ) {
 311                         $l = self::sanitizeLangCode( $l );
 312                         $obj = Language::factory( $l );
 313                         $this->lang = $obj;
 314                 } else {
 315                         throw new MWException( __METHOD__ . " was passed an invalid type of data." );
 316                 }
 317         }
 318
 319         /**
 320          * Get the Language object.
 321          * Initialization of user or request objects can depend on this.
 322          * @return Language
 323          * @throws Exception
 324          * @since 1.19
 325          */
 326         public function getLanguage() {
 327                 if ( isset( $this->recursion ) ) {
 328                         trigger_error( "Recursion detected in " . __METHOD__, E_USER_WARNING );
 329                         $e = new Exception;
 330                         wfDebugLog( 'recursion-guard', "Recursion detected:\n" . $e->getTraceAsString() );
 331
 332                         $code = $this->getConfig()->get( 'LanguageCode' ) ?: 'en';
 333                         $this->lang = Language::factory( $code );
 334                 } elseif ( $this->lang === null ) {
 335                         $this->recursion = true;
 336
 337                         global $wgContLang;
 338
 339                         try {
 340                                 $request = $this->getRequest();
 341                                 $user = $this->getUser();
 342
 343                                 $code = $request->getVal( 'uselang', 'user' );
 344                                 if ( $code === 'user' ) {
 345                                         $code = $user->getOption( 'language' );
 346                                 }
 347                                 $code = self::sanitizeLangCode( $code );
 348
 349                                 Hooks::run( 'UserGetLanguageObject', array( $user, &$code, $this ) );
 350
 351                                 if ( $code === $this->getConfig()->get( 'LanguageCode' ) ) {
 352                                         $this->lang = $wgContLang;
 353                                 } else {
 354                                         $obj = Language::factory( $code );
 355                                         $this->lang = $obj;
 356                                 }
 357
 358                                 unset( $this->recursion );
 359                         }
 360                         catch ( Exception $ex ) {
 361                                 unset( $this->recursion );
 362                                 throw $ex;
 363                         }
 364                 }
 365
 366                 return $this->lang;
 367         }
 368
 369         /**
 370          * Set the Skin object
 371          *
 372          * @param Skin $s
 373          */
 374         public function setSkin( Skin $s ) {
 375                 $this->skin = clone $s;
 376                 $this->skin->setContext( $this );
 377         }
 378
 379         /**
 380          * Get the Skin object
 381          *
 382          * @return Skin
 383          */
 384         public function getSkin() {
 385                 if ( $this->skin === null ) {
 386                         $skin = null;
 387                         Hooks::run( 'RequestContextCreateSkin', array( $this, &$skin ) );
 388                         $factory = SkinFactory::getDefaultInstance();
 389
 390                         // If the hook worked try to set a skin from it
 391                         if ( $skin instanceof Skin ) {
 392                                 $this->skin = $skin;
 393                         } elseif ( is_string( $skin ) ) {
 394                                 // Normalize the key, just in case the hook did something weird.
 395                                 $normalized = Skin::normalizeKey( $skin );
 396                                 $this->skin = $factory->makeSkin( $normalized );
 397                         }
 398
 399                         // If this is still null (the hook didn't run or didn't work)
 400                         // then go through the normal processing to load a skin
 401                         if ( $this->skin === null ) {
 402                                 if ( !in_array( 'skin', $this->getConfig()->get( 'HiddenPrefs' ) ) ) {
 403                                         # get the user skin
 404                                         $userSkin = $this->getUser()->getOption( 'skin' );
 405                                         $userSkin = $this->getRequest()->getVal( 'useskin', $userSkin );
 406                                 } else {
 407                                         # if we're not allowing users to override, then use the default
 408                                         $userSkin = $this->getConfig()->get( 'DefaultSkin' );
 409                                 }
 410
 411                                 // Normalize the key in case the user is passing gibberish
 412                                 // or has old preferences (bug 69566).
 413                                 $normalized = Skin::normalizeKey( $userSkin );
 414
 415                                 // Skin::normalizeKey will also validate it, so
 416                                 // this won't throw an exception
 417                                 $this->skin = $factory->makeSkin( $normalized );
 418                         }
 419
 420                         // After all that set a context on whatever skin got created
 421                         $this->skin->setContext( $this );
 422                 }
 423
 424                 return $this->skin;
 425         }
 426
 427         /** Helpful methods **/
 428
 429         /**
 430          * Get a Message object with context set
 431          * Parameters are the same as wfMessage()
 432          *
 433          * @param mixed ...
 434          * @return Message
 435          */
 436         public function msg() {
 437                 $args = func_get_args();
 438
 439                 return call_user_func_array( 'wfMessage', $args )->setContext( $this );
 440         }
 441
 442         /** Static methods **/
 443
 444         /**
 445          * Get the RequestContext object associated with the main request
 446          *
 447          * @return RequestContext
 448          */
 449         public static function getMain() {
 450                 if ( self::$instance === null ) {
 451                         self::$instance = new self;
 452                 }
 453
 454                 return self::$instance;
 455         }
 456
 457         /**
 458          * Get the RequestContext object associated with the main request
 459          * and gives a warning to the log, to find places, where a context maybe is missing.
 460          *
 461          * @param string $func
 462          * @return RequestContext
 463          * @since 1.24
 464          */
 465         public static function getMainAndWarn( $func = __METHOD__ ) {
 466                 wfDebug( $func . ' called without context. ' .
 467                         "Using RequestContext::getMain() for sanity\n" );
 468
 469                 return self::getMain();
 470         }
 471
 472         /**
 473          * Resets singleton returned by getMain(). Should be called only from unit tests.
 474          */
 475         public static function resetMain() {
 476                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 477                         throw new MWException( __METHOD__ . '() should be called only from unit tests!' );
 478                 }
 479                 self::$instance = null;
 480         }
 481
 482         /**
 483          * Export the resolved user IP, HTTP headers, user ID, and session ID.
 484          * The result will be reasonably sized to allow for serialization.
 485          *
 486          * @return array
 487          * @since 1.21
 488          */
 489         public function exportSession() {
 490                 return array(
 491                         'ip' => $this->getRequest()->getIP(),
 492                         'headers' => $this->getRequest()->getAllHeaders(),
 493                         'sessionId' => session_id(),
 494                         'userId' => $this->getUser()->getId()
 495                 );
 496         }
 497
 498         /**
 499          * Import an client IP address, HTTP headers, user ID, and session ID
 500          *
 501          * This sets the current session, $wgUser, and $wgRequest from $params.
 502          * Once the return value falls out of scope, the old context is restored.
 503          * This method should only be called in contexts where there is no session
 504          * ID or end user receiving the response (CLI or HTTP job runners). This
 505          * is partly enforced, and is done so to avoid leaking cookies if certain
 506          * error conditions arise.
 507          *
 508          * This is useful when background scripts inherit context when acting on
 509          * behalf of a user. In general the 'sessionId' parameter should be set
 510          * to an empty string unless session importing is *truly* needed. This
 511          * feature is somewhat deprecated.
 512          *
 513          * @note suhosin.session.encrypt may interfere with this method.
 514          *
 515          * @param array $params Result of RequestContext::exportSession()
 516          * @return ScopedCallback
 517          * @throws MWException
 518          * @since 1.21
 519          */
 520         public static function importScopedSession( array $params ) {
 521                 if ( session_id() != '' && strlen( $params['sessionId'] ) ) {
 522                         // Sanity check to avoid sending random cookies for the wrong users.
 523                         // This method should only called by CLI scripts or by HTTP job runners.
 524                         throw new MWException( "Sessions can only be imported when none is active." );
 525                 } elseif ( !IP::isValid( $params['ip'] ) ) {
 526                         throw new MWException( "Invalid client IP address '{$params['ip']}'." );
 527                 }
 528
 529                 if ( $params['userId'] ) { // logged-in user
 530                         $user = User::newFromId( $params['userId'] );
 531                         $user->load();
 532                         if ( !$user->getId() ) {
 533                                 throw new MWException( "No user with ID '{$params['userId']}'." );
 534                         }
 535                 } else { // anon user
 536                         $user = User::newFromName( $params['ip'], false );
 537                 }
 538
 539                 $importSessionFunc = function ( User $user, array $params ) {
 540                         global $wgRequest, $wgUser;
 541
 542                         $context = RequestContext::getMain();
 543                         // Commit and close any current session
 544                         session_write_close(); // persist
 545                         session_id( '' ); // detach
 546                         $_SESSION = array(); // clear in-memory array
 547                         // Remove any user IP or agent information
 548                         $context->setRequest( new FauxRequest() );
 549                         $wgRequest = $context->getRequest(); // b/c
 550                         // Now that all private information is detached from the user, it should
 551                         // be safe to load the new user. If errors occur or an exception is thrown
 552                         // and caught (leaving the main context in a mixed state), there is no risk
 553                         // of the User object being attached to the wrong IP, headers, or session.
 554                         $context->setUser( $user );
 555                         $wgUser = $context->getUser(); // b/c
 556                         if ( strlen( $params['sessionId'] ) ) { // don't make a new random ID
 557                                 wfSetupSession( $params['sessionId'] ); // sets $_SESSION
 558                         }
 559                         $request = new FauxRequest( array(), false, $_SESSION );
 560                         $request->setIP( $params['ip'] );
 561                         foreach ( $params['headers'] as $name => $value ) {
 562                                 $request->setHeader( $name, $value );
 563                         }
 564                         // Set the current context to use the new WebRequest
 565                         $context->setRequest( $request );
 566                         $wgRequest = $context->getRequest(); // b/c
 567                 };
 568
 569                 // Stash the old session and load in the new one
 570                 $oUser = self::getMain()->getUser();
 571                 $oParams = self::getMain()->exportSession();
 572                 $oRequest = self::getMain()->getRequest();
 573                 $importSessionFunc( $user, $params );
 574
 575                 // Set callback to save and close the new session and reload the old one
 576                 return new ScopedCallback(
 577                         function () use ( $importSessionFunc, $oUser, $oParams, $oRequest ) {
 578                                 global $wgRequest;
 579                                 $importSessionFunc( $oUser, $oParams );
 580                                 // Restore the exact previous Request object (instead of leaving FauxRequest)
 581                                 RequestContext::getMain()->setRequest( $oRequest );
 582                                 $wgRequest = RequestContext::getMain()->getRequest(); // b/c
 583                         }
 584                 );
 585         }
 586
 587         /**
 588          * Create a new extraneous context. The context is filled with information
 589          * external to the current session.
 590          * - Title is specified by argument
 591          * - Request is a FauxRequest, or a FauxRequest can be specified by argument
 592          * - User is an anonymous user, for separation IPv4 localhost is used
 593          * - Language will be based on the anonymous user and request, may be content
 594          *   language or a uselang param in the fauxrequest data may change the lang
 595          * - Skin will be based on the anonymous user, should be the wiki's default skin
 596          *
 597          * @param Title $title Title to use for the extraneous request
 598          * @param WebRequest|array $request A WebRequest or data to use for a FauxRequest
 599          * @return RequestContext
 600          */
 601         public static function newExtraneousContext( Title $title, $request = array() ) {
 602                 $context = new self;
 603                 $context->setTitle( $title );
 604                 if ( $request instanceof WebRequest ) {
 605                         $context->setRequest( $request );
 606                 } else {
 607                         $context->setRequest( new FauxRequest( $request ) );
 608                 }
 609                 $context->user = User::newFromName( '127.0.0.1', false );
 610
 611                 return $context;
 612         }
 613 }