includes/api/ApiMain.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 4, 2006
   6  *
   7  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  * @defgroup API API
  26  */
  27
  28 /**
  29  * This is the main API class, used for both external and internal processing.
  30  * When executed, it will create the requested formatter object,
  31  * instantiate and execute an object associated with the needed action,
  32  * and use formatter to print results.
  33  * In case of an exception, an error message will be printed using the same formatter.
  34  *
  35  * To use API from another application, run it using FauxRequest object, in which
  36  * case any internal exceptions will not be handled but passed up to the caller.
  37  * After successful execution, use getResult() for the resulting data.
  38  *
  39  * @ingroup API
  40  */
  41 class ApiMain extends ApiBase {
  42         /**
  43          * When no format parameter is given, this format will be used
  44          */
  45         const API_DEFAULT_FORMAT = 'jsonfm';
  46
  47         /**
  48          * List of available modules: action name => module class
  49          */
  50         private static $Modules = array(
  51                 'login' => 'ApiLogin',
  52                 'logout' => 'ApiLogout',
  53                 'createaccount' => 'ApiCreateAccount',
  54                 'query' => 'ApiQuery',
  55                 'expandtemplates' => 'ApiExpandTemplates',
  56                 'parse' => 'ApiParse',
  57                 'stashedit' => 'ApiStashEdit',
  58                 'opensearch' => 'ApiOpenSearch',
  59                 'feedcontributions' => 'ApiFeedContributions',
  60                 'feedrecentchanges' => 'ApiFeedRecentChanges',
  61                 'feedwatchlist' => 'ApiFeedWatchlist',
  62                 'help' => 'ApiHelp',
  63                 'paraminfo' => 'ApiParamInfo',
  64                 'rsd' => 'ApiRsd',
  65                 'compare' => 'ApiComparePages',
  66                 'tokens' => 'ApiTokens',
  67                 'checktoken' => 'ApiCheckToken',
  68
  69                 // Write modules
  70                 'purge' => 'ApiPurge',
  71                 'setnotificationtimestamp' => 'ApiSetNotificationTimestamp',
  72                 'rollback' => 'ApiRollback',
  73                 'delete' => 'ApiDelete',
  74                 'undelete' => 'ApiUndelete',
  75                 'protect' => 'ApiProtect',
  76                 'block' => 'ApiBlock',
  77                 'unblock' => 'ApiUnblock',
  78                 'move' => 'ApiMove',
  79                 'edit' => 'ApiEditPage',
  80                 'upload' => 'ApiUpload',
  81                 'filerevert' => 'ApiFileRevert',
  82                 'emailuser' => 'ApiEmailUser',
  83                 'watch' => 'ApiWatch',
  84                 'patrol' => 'ApiPatrol',
  85                 'import' => 'ApiImport',
  86                 'clearhasmsg' => 'ApiClearHasMsg',
  87                 'userrights' => 'ApiUserrights',
  88                 'options' => 'ApiOptions',
  89                 'imagerotate' => 'ApiImageRotate',
  90                 'revisiondelete' => 'ApiRevisionDelete',
  91                 'managetags' => 'ApiManageTags',
  92                 'tag' => 'ApiTag',
  93                 'mergehistory' => 'ApiMergeHistory',
  94         );
  95
  96         /**
  97          * List of available formats: format name => format class
  98          */
  99         private static $Formats = array(
 100                 'json' => 'ApiFormatJson',
 101                 'jsonfm' => 'ApiFormatJson',
 102                 'php' => 'ApiFormatPhp',
 103                 'phpfm' => 'ApiFormatPhp',
 104                 'xml' => 'ApiFormatXml',
 105                 'xmlfm' => 'ApiFormatXml',
 106                 'rawfm' => 'ApiFormatJson',
 107                 'none' => 'ApiFormatNone',
 108         );
 109
 110         // @codingStandardsIgnoreStart String contenation on "msg" not allowed to break long line
 111         /**
 112          * List of user roles that are specifically relevant to the API.
 113          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 114          *                           'params' => array ( $someVarToSubst ) ),
 115          *                          );
 116          */
 117         private static $mRights = array(
 118                 'writeapi' => array(
 119                         'msg' => 'right-writeapi',
 120                         'params' => array()
 121                 ),
 122                 'apihighlimits' => array(
 123                         'msg' => 'api-help-right-apihighlimits',
 124                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 125                 )
 126         );
 127         // @codingStandardsIgnoreEnd
 128
 129         /**
 130          * @var ApiFormatBase
 131          */
 132         private $mPrinter;
 133
 134         private $mModuleMgr, $mResult, $mErrorFormatter, $mContinuationManager;
 135         private $mAction;
 136         private $mEnableWrite;
 137         private $mInternalMode, $mSquidMaxage, $mModule;
 138
 139         private $mCacheMode = 'private';
 140         private $mCacheControl = array();
 141         private $mParamsUsed = array();
 142
 143         /**
 144          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 145          *
 146          * @param IContextSource|WebRequest $context If this is an instance of
 147          *    FauxRequest, errors are thrown and no printing occurs
 148          * @param bool $enableWrite Should be set to true if the api may modify data
 149          */
 150         public function __construct( $context = null, $enableWrite = false ) {
 151                 if ( $context === null ) {
 152                         $context = RequestContext::getMain();
 153                 } elseif ( $context instanceof WebRequest ) {
 154                         // BC for pre-1.19
 155                         $request = $context;
 156                         $context = RequestContext::getMain();
 157                 }
 158                 // We set a derivative context so we can change stuff later
 159                 $this->setContext( new DerivativeContext( $context ) );
 160
 161                 if ( isset( $request ) ) {
 162                         $this->getContext()->setRequest( $request );
 163                 }
 164
 165                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 166
 167                 // Special handling for the main module: $parent === $this
 168                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 169
 170                 if ( !$this->mInternalMode ) {
 171                         // Impose module restrictions.
 172                         // If the current user cannot read,
 173                         // Remove all modules other than login
 174                         global $wgUser;
 175
 176                         if ( $this->lacksSameOriginSecurity() ) {
 177                                 // If we're in a mode that breaks the same-origin policy, strip
 178                                 // user credentials for security.
 179                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 180                                 $wgUser = new User();
 181                                 $this->getContext()->setUser( $wgUser );
 182                         }
 183                 }
 184
 185                 $uselang = $this->getParameter( 'uselang' );
 186                 if ( $uselang === 'user' ) {
 187                         // Assume the parent context is going to return the user language
 188                         // for uselang=user (see T85635).
 189                 } else {
 190                         if ( $uselang === 'content' ) {
 191                                 global $wgContLang;
 192                                 $uselang = $wgContLang->getCode();
 193                         }
 194                         $code = RequestContext::sanitizeLangCode( $uselang );
 195                         $this->getContext()->setLanguage( $code );
 196                         if ( !$this->mInternalMode ) {
 197                                 global $wgLang;
 198                                 $wgLang = $this->getContext()->getLanguage();
 199                                 RequestContext::getMain()->setLanguage( $wgLang );
 200                         }
 201                 }
 202
 203                 $config = $this->getConfig();
 204                 $this->mModuleMgr = new ApiModuleManager( $this );
 205                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 206                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 207                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 208                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 209
 210                 Hooks::run( 'ApiMain::moduleManager', array( $this->mModuleMgr ) );
 211
 212                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 213                 $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 214                 $this->mResult->setErrorFormatter( $this->mErrorFormatter );
 215                 $this->mResult->setMainForContinuation( $this );
 216                 $this->mContinuationManager = null;
 217                 $this->mEnableWrite = $enableWrite;
 218
 219                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 220                 $this->mCommit = false;
 221         }
 222
 223         /**
 224          * Return true if the API was started by other PHP code using FauxRequest
 225          * @return bool
 226          */
 227         public function isInternalMode() {
 228                 return $this->mInternalMode;
 229         }
 230
 231         /**
 232          * Get the ApiResult object associated with current request
 233          *
 234          * @return ApiResult
 235          */
 236         public function getResult() {
 237                 return $this->mResult;
 238         }
 239
 240         /**
 241          * Get the ApiErrorFormatter object associated with current request
 242          * @return ApiErrorFormatter
 243          */
 244         public function getErrorFormatter() {
 245                 return $this->mErrorFormatter;
 246         }
 247
 248         /**
 249          * Get the continuation manager
 250          * @return ApiContinuationManager|null
 251          */
 252         public function getContinuationManager() {
 253                 return $this->mContinuationManager;
 254         }
 255
 256         /**
 257          * Set the continuation manager
 258          * @param ApiContinuationManager|null
 259          */
 260         public function setContinuationManager( $manager ) {
 261                 if ( $manager !== null ) {
 262                         if ( !$manager instanceof ApiContinuationManager ) {
 263                                 throw new InvalidArgumentException( __METHOD__ . ': Was passed ' .
 264                                         is_object( $manager ) ? get_class( $manager ) : gettype( $manager )
 265                                 );
 266                         }
 267                         if ( $this->mContinuationManager !== null ) {
 268                                 throw new UnexpectedValueException(
 269                                         __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 270                                         ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 271                                 );
 272                         }
 273                 }
 274                 $this->mContinuationManager = $manager;
 275         }
 276
 277         /**
 278          * Get the API module object. Only works after executeAction()
 279          *
 280          * @return ApiBase
 281          */
 282         public function getModule() {
 283                 return $this->mModule;
 284         }
 285
 286         /**
 287          * Get the result formatter object. Only works after setupExecuteAction()
 288          *
 289          * @return ApiFormatBase
 290          */
 291         public function getPrinter() {
 292                 return $this->mPrinter;
 293         }
 294
 295         /**
 296          * Set how long the response should be cached.
 297          *
 298          * @param int $maxage
 299          */
 300         public function setCacheMaxAge( $maxage ) {
 301                 $this->setCacheControl( array(
 302                         'max-age' => $maxage,
 303                         's-maxage' => $maxage
 304                 ) );
 305         }
 306
 307         /**
 308          * Set the type of caching headers which will be sent.
 309          *
 310          * @param string $mode One of:
 311          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 312          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 313          *         not provided by any of these means, the object will be private.
 314          *    - 'private':    Cache this object only in private client-side caches.
 315          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 316          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 317          *         set consistently for a given URL, it cannot be set differently depending on
 318          *         things like the contents of the database, or whether the user is logged in.
 319          *
 320          *  If the wiki does not allow anonymous users to read it, the mode set here
 321          *  will be ignored, and private caching headers will always be sent. In other words,
 322          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 323          *  view.
 324          *
 325          *  For user-dependent data, the private mode should generally be used. The
 326          *  anon-public-user-private mode should only be used where there is a particularly
 327          *  good performance reason for caching the anonymous response, but where the
 328          *  response to logged-in users may differ, or may contain private data.
 329          *
 330          *  If this function is never called, then the default will be the private mode.
 331          */
 332         public function setCacheMode( $mode ) {
 333                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 334                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 335
 336                         // Ignore for forwards-compatibility
 337                         return;
 338                 }
 339
 340                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 341                         // Private wiki, only private headers
 342                         if ( $mode !== 'private' ) {
 343                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 344
 345                                 return;
 346                         }
 347                 }
 348
 349                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 350                         // User language is used for i18n, so we don't want to publicly
 351                         // cache. Anons are ok, because if they have non-default language
 352                         // then there's an appropriate Vary header set by whatever set
 353                         // their non-default language.
 354                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 355                                 "'anon-public-user-private' due to uselang=user\n" );
 356                         $mode = 'anon-public-user-private';
 357                 }
 358
 359                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 360                 $this->mCacheMode = $mode;
 361         }
 362
 363         /**
 364          * Set directives (key/value pairs) for the Cache-Control header.
 365          * Boolean values will be formatted as such, by including or omitting
 366          * without an equals sign.
 367          *
 368          * Cache control values set here will only be used if the cache mode is not
 369          * private, see setCacheMode().
 370          *
 371          * @param array $directives
 372          */
 373         public function setCacheControl( $directives ) {
 374                 $this->mCacheControl = $directives + $this->mCacheControl;
 375         }
 376
 377         /**
 378          * Create an instance of an output formatter by its name
 379          *
 380          * @param string $format
 381          *
 382          * @return ApiFormatBase
 383          */
 384         public function createPrinterByName( $format ) {
 385                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 386                 if ( $printer === null ) {
 387                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 388                 }
 389
 390                 return $printer;
 391         }
 392
 393         /**
 394          * Execute api request. Any errors will be handled if the API was called by the remote client.
 395          */
 396         public function execute() {
 397                 if ( $this->mInternalMode ) {
 398                         $this->executeAction();
 399                 } else {
 400                         $this->executeActionWithErrorHandling();
 401                 }
 402         }
 403
 404         /**
 405          * Execute an action, and in case of an error, erase whatever partial results
 406          * have been accumulated, and replace it with an error message and a help screen.
 407          */
 408         protected function executeActionWithErrorHandling() {
 409                 // Verify the CORS header before executing the action
 410                 if ( !$this->handleCORS() ) {
 411                         // handleCORS() has sent a 403, abort
 412                         return;
 413                 }
 414
 415                 // Exit here if the request method was OPTIONS
 416                 // (assume there will be a followup GET or POST)
 417                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 418                         return;
 419                 }
 420
 421                 // In case an error occurs during data output,
 422                 // clear the output buffer and print just the error information
 423                 $obLevel = ob_get_level();
 424                 ob_start();
 425
 426                 $t = microtime( true );
 427                 try {
 428                         $this->executeAction();
 429                         $isError = false;
 430                 } catch ( Exception $e ) {
 431                         $this->handleException( $e );
 432                         $isError = true;
 433                 }
 434
 435                 // Log the request whether or not there was an error
 436                 $this->logRequest( microtime( true ) - $t );
 437
 438                 // Commit DBs and send any related cookies and headers
 439                 MediaWiki::preOutputCommit( $this->getContext() );
 440
 441                 // Send cache headers after any code which might generate an error, to
 442                 // avoid sending public cache headers for errors.
 443                 $this->sendCacheHeaders( $isError );
 444
 445                 // Executing the action might have already messed with the output
 446                 // buffers.
 447                 while ( ob_get_level() > $obLevel ) {
 448                         ob_end_flush();
 449                 }
 450         }
 451
 452         /**
 453          * Handle an exception as an API response
 454          *
 455          * @since 1.23
 456          * @param Exception $e
 457          */
 458         protected function handleException( Exception $e ) {
 459                 // Bug 63145: Rollback any open database transactions
 460                 if ( !( $e instanceof UsageException ) ) {
 461                         // UsageExceptions are intentional, so don't rollback if that's the case
 462                         try {
 463                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 464                         } catch ( DBError $e2 ) {
 465                                 // Rollback threw an exception too. Log it, but don't interrupt
 466                                 // our regularly scheduled exception handling.
 467                                 MWExceptionHandler::logException( $e2 );
 468                         }
 469                 }
 470
 471                 // Allow extra cleanup and logging
 472                 Hooks::run( 'ApiMain::onException', array( $this, $e ) );
 473
 474                 // Log it
 475                 if ( !( $e instanceof UsageException ) ) {
 476                         MWExceptionHandler::logException( $e );
 477                 }
 478
 479                 // Handle any kind of exception by outputting properly formatted error message.
 480                 // If this fails, an unhandled exception should be thrown so that global error
 481                 // handler will process and log it.
 482
 483                 $errCode = $this->substituteResultWithError( $e );
 484
 485                 // Error results should not be cached
 486                 $this->setCacheMode( 'private' );
 487
 488                 $response = $this->getRequest()->response();
 489                 $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 490                 if ( $e->getCode() === 0 ) {
 491                         $response->header( $headerStr );
 492                 } else {
 493                         $response->header( $headerStr, true, $e->getCode() );
 494                 }
 495
 496                 // Reset and print just the error message
 497                 ob_clean();
 498
 499                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 500                 $this->createErrorPrinter();
 501
 502                 try {
 503                         $this->printResult( true );
 504                 } catch ( UsageException $ex ) {
 505                         // The error printer itself is failing. Try suppressing its request
 506                         // parameters and redo.
 507                         $this->setWarning(
 508                                 'Error printer failed (will retry without params): ' . $ex->getMessage()
 509                         );
 510                         $this->mPrinter = null;
 511                         $this->createErrorPrinter();
 512                         $this->mPrinter->forceDefaultParams();
 513                         $this->printResult( true );
 514                 }
 515         }
 516
 517         /**
 518          * Handle an exception from the ApiBeforeMain hook.
 519          *
 520          * This tries to print the exception as an API response, to be more
 521          * friendly to clients. If it fails, it will rethrow the exception.
 522          *
 523          * @since 1.23
 524          * @param Exception $e
 525          * @throws Exception
 526          */
 527         public static function handleApiBeforeMainException( Exception $e ) {
 528                 ob_start();
 529
 530                 try {
 531                         $main = new self( RequestContext::getMain(), false );
 532                         $main->handleException( $e );
 533                 } catch ( Exception $e2 ) {
 534                         // Nope, even that didn't work. Punt.
 535                         throw $e;
 536                 }
 537
 538                 // Log the request and reset cache headers
 539                 $main->logRequest( 0 );
 540                 $main->sendCacheHeaders( true );
 541
 542                 ob_end_flush();
 543         }
 544
 545         /**
 546          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 547          *
 548          * If no origin parameter is present, nothing happens.
 549          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 550          * is set and false is returned.
 551          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 552          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 553          * headers are set.
 554          * http://www.w3.org/TR/cors/#resource-requests
 555          * http://www.w3.org/TR/cors/#resource-preflight-requests
 556          *
 557          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 558          */
 559         protected function handleCORS() {
 560                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 561                 if ( $originParam === null ) {
 562                         // No origin parameter, nothing to do
 563                         return true;
 564                 }
 565
 566                 $request = $this->getRequest();
 567                 $response = $request->response();
 568
 569                 // Origin: header is a space-separated list of origins, check all of them
 570                 $originHeader = $request->getHeader( 'Origin' );
 571                 if ( $originHeader === false ) {
 572                         $origins = array();
 573                 } else {
 574                         $originHeader = trim( $originHeader );
 575                         $origins = preg_split( '/\s+/', $originHeader );
 576                 }
 577
 578                 if ( !in_array( $originParam, $origins ) ) {
 579                         // origin parameter set but incorrect
 580                         // Send a 403 response
 581                         $response->statusHeader( 403 );
 582                         $response->header( 'Cache-Control: no-cache' );
 583                         echo "'origin' parameter does not match Origin header\n";
 584
 585                         return false;
 586                 }
 587
 588                 $config = $this->getConfig();
 589                 $matchOrigin = count( $origins ) === 1 && self::matchOrigin(
 590                         $originParam,
 591                         $config->get( 'CrossSiteAJAXdomains' ),
 592                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 593                 );
 594
 595                 if ( $matchOrigin ) {
 596                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 597                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 598                         if ( $preflight ) {
 599                                 // This is a CORS preflight request
 600                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 601                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 602                                         return true;
 603                                 }
 604                                 // We allow the actual request to send the following headers
 605                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 606                                 if ( $requestedHeaders !== false ) {
 607                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 608                                                 return true;
 609                                         }
 610                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 611                                 }
 612
 613                                 // We only allow the actual request to be GET or POST
 614                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 615                         }
 616
 617                         $response->header( "Access-Control-Allow-Origin: $originHeader" );
 618                         $response->header( 'Access-Control-Allow-Credentials: true' );
 619                         // http://www.w3.org/TR/resource-timing/#timing-allow-origin
 620                         $response->header( "Timing-Allow-Origin: $originHeader" );
 621
 622                         if ( !$preflight ) {
 623                                 $response->header(
 624                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag'
 625                                 );
 626                         }
 627                 }
 628
 629                 $this->getOutput()->addVaryHeader( 'Origin' );
 630                 return true;
 631         }
 632
 633         /**
 634          * Attempt to match an Origin header against a set of rules and a set of exceptions
 635          * @param string $value Origin header
 636          * @param array $rules Set of wildcard rules
 637          * @param array $exceptions Set of wildcard rules
 638          * @return bool True if $value matches a rule in $rules and doesn't match
 639          *    any rules in $exceptions, false otherwise
 640          */
 641         protected static function matchOrigin( $value, $rules, $exceptions ) {
 642                 foreach ( $rules as $rule ) {
 643                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 644                                 // Rule matches, check exceptions
 645                                 foreach ( $exceptions as $exc ) {
 646                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 647                                                 return false;
 648                                         }
 649                                 }
 650
 651                                 return true;
 652                         }
 653                 }
 654
 655                 return false;
 656         }
 657
 658         /**
 659          * Attempt to validate the value of Access-Control-Request-Headers against a list
 660          * of headers that we allow the follow up request to send.
 661          *
 662          * @param string $requestedHeaders Comma seperated list of HTTP headers
 663          * @return bool True if all requested headers are in the list of allowed headers
 664          */
 665         protected static function matchRequestedHeaders( $requestedHeaders ) {
 666                 if ( trim( $requestedHeaders ) === '' ) {
 667                         return true;
 668                 }
 669                 $requestedHeaders = explode( ',', $requestedHeaders );
 670                 $allowedAuthorHeaders = array_flip( array(
 671                         /* simple headers (see spec) */
 672                         'accept',
 673                         'accept-language',
 674                         'content-language',
 675                         'content-type',
 676                         /* non-authorable headers in XHR, which are however requested by some UAs */
 677                         'accept-encoding',
 678                         'dnt',
 679                         'origin',
 680                         /* MediaWiki whitelist */
 681                         'api-user-agent',
 682                 ) );
 683                 foreach ( $requestedHeaders as $rHeader ) {
 684                         $rHeader = strtolower( trim( $rHeader ) );
 685                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 686                                 wfDebugLog( 'api', 'CORS preflight failed on requested header: ' . $rHeader );
 687                                 return false;
 688                         }
 689                 }
 690                 return true;
 691         }
 692
 693         /**
 694          * Helper function to convert wildcard string into a regex
 695          * '*' => '.*?'
 696          * '?' => '.'
 697          *
 698          * @param string $wildcard String with wildcards
 699          * @return string Regular expression
 700          */
 701         protected static function wildcardToRegex( $wildcard ) {
 702                 $wildcard = preg_quote( $wildcard, '/' );
 703                 $wildcard = str_replace(
 704                         array( '\*', '\?' ),
 705                         array( '.*?', '.' ),
 706                         $wildcard
 707                 );
 708
 709                 return "/^https?:\/\/$wildcard$/";
 710         }
 711
 712         /**
 713          * Send caching headers
 714          * @param boolean $isError Whether an error response is being output
 715          * @since 1.26 added $isError parameter
 716          */
 717         protected function sendCacheHeaders( $isError ) {
 718                 $response = $this->getRequest()->response();
 719                 $out = $this->getOutput();
 720
 721                 $config = $this->getConfig();
 722
 723                 if ( $config->get( 'VaryOnXFP' ) ) {
 724                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 725                 }
 726
 727                 if ( !$isError && $this->mModule &&
 728                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 729                 ) {
 730                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 731                         if ( $etag !== null ) {
 732                                 $response->header( "ETag: $etag" );
 733                         }
 734                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 735                         if ( $lastMod !== null ) {
 736                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 737                         }
 738                 }
 739
 740                 // The logic should be:
 741                 // $this->mCacheControl['max-age'] is set?
 742                 //    Use it, the module knows better than our guess.
 743                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 744                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 745                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 746                 $maxage = 0;
 747                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 748                         $maxage = $this->mCacheControl['max-age'];
 749                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 750                         $this->mCacheMode !== 'private'
 751                 ) {
 752                         $maxage = $this->getParameter( 'maxage' );
 753                 }
 754                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 755
 756                 if ( $this->mCacheMode == 'private' ) {
 757                         $response->header( "Cache-Control: $privateCache" );
 758                         return;
 759                 }
 760
 761                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 762                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 763                         $out->addVaryHeader( 'Cookie' );
 764                         $response->header( $out->getVaryHeader() );
 765                         if ( $useKeyHeader ) {
 766                                 $response->header( $out->getKeyHeader() );
 767                                 if ( $out->haveCacheVaryCookies() ) {
 768                                         // Logged in, mark this request private
 769                                         $response->header( "Cache-Control: $privateCache" );
 770                                         return;
 771                                 }
 772                                 // Logged out, send normal public headers below
 773                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 774                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 775                                 // Mark request private
 776                                 $response->header( "Cache-Control: $privateCache" );
 777
 778                                 return;
 779                         } // else no Key and anonymous, send public headers below
 780                 }
 781
 782                 // Send public headers
 783                 $response->header( $out->getVaryHeader() );
 784                 if ( $useKeyHeader ) {
 785                         $response->header( $out->getKeyHeader() );
 786                 }
 787
 788                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 789                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 790                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 791                 }
 792                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 793                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 794                 }
 795
 796                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 797                         // Public cache not requested
 798                         // Sending a Vary header in this case is harmless, and protects us
 799                         // against conditional calls of setCacheMaxAge().
 800                         $response->header( "Cache-Control: $privateCache" );
 801
 802                         return;
 803                 }
 804
 805                 $this->mCacheControl['public'] = true;
 806
 807                 // Send an Expires header
 808                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 809                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 810                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 811
 812                 // Construct the Cache-Control header
 813                 $ccHeader = '';
 814                 $separator = '';
 815                 foreach ( $this->mCacheControl as $name => $value ) {
 816                         if ( is_bool( $value ) ) {
 817                                 if ( $value ) {
 818                                         $ccHeader .= $separator . $name;
 819                                         $separator = ', ';
 820                                 }
 821                         } else {
 822                                 $ccHeader .= $separator . "$name=$value";
 823                                 $separator = ', ';
 824                         }
 825                 }
 826
 827                 $response->header( "Cache-Control: $ccHeader" );
 828         }
 829
 830         /**
 831          * Create the printer for error output
 832          */
 833         private function createErrorPrinter() {
 834                 if ( !isset( $this->mPrinter ) ) {
 835                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 836                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 837                                 $value = self::API_DEFAULT_FORMAT;
 838                         }
 839                         $this->mPrinter = $this->createPrinterByName( $value );
 840                 }
 841
 842                 // Printer may not be able to handle errors. This is particularly
 843                 // likely if the module returns something for getCustomPrinter().
 844                 if ( !$this->mPrinter->canPrintErrors() ) {
 845                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
 846                 }
 847         }
 848
 849         /**
 850          * Replace the result data with the information about an exception.
 851          * Returns the error code
 852          * @param Exception $e
 853          * @return string
 854          */
 855         protected function substituteResultWithError( $e ) {
 856                 $result = $this->getResult();
 857                 $config = $this->getConfig();
 858
 859                 if ( $e instanceof UsageException ) {
 860                         // User entered incorrect parameters - generate error response
 861                         $errMessage = $e->getMessageArray();
 862                         $link = wfExpandUrl( wfScript( 'api' ) );
 863                         ApiResult::setContentValue( $errMessage, 'docref', "See $link for API usage" );
 864                 } else {
 865                         // Something is seriously wrong
 866                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
 867                                 $info = 'Database query error';
 868                         } else {
 869                                 $info = "Exception Caught: {$e->getMessage()}";
 870                         }
 871
 872                         $errMessage = array(
 873                                 'code' => 'internal_api_error_' . get_class( $e ),
 874                                 'info' => '[' . MWExceptionHandler::getLogId( $e ) . '] ' . $info,
 875                         );
 876                         if ( $config->get( 'ShowExceptionDetails' ) ) {
 877                                 ApiResult::setContentValue(
 878                                         $errMessage,
 879                                         'trace',
 880                                         MWExceptionHandler::getRedactedTraceAsString( $e )
 881                                 );
 882                         }
 883                 }
 884
 885                 // Remember all the warnings to re-add them later
 886                 $warnings = $result->getResultData( array( 'warnings' ) );
 887
 888                 $result->reset();
 889                 // Re-add the id
 890                 $requestid = $this->getParameter( 'requestid' );
 891                 if ( !is_null( $requestid ) ) {
 892                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
 893                 }
 894                 if ( $config->get( 'ShowHostnames' ) ) {
 895                         // servedby is especially useful when debugging errors
 896                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
 897                 }
 898                 if ( $warnings !== null ) {
 899                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
 900                 }
 901
 902                 $result->addValue( null, 'error', $errMessage, ApiResult::NO_SIZE_CHECK );
 903
 904                 return $errMessage['code'];
 905         }
 906
 907         /**
 908          * Set up for the execution.
 909          * @return array
 910          */
 911         protected function setupExecuteAction() {
 912                 // First add the id to the top element
 913                 $result = $this->getResult();
 914                 $requestid = $this->getParameter( 'requestid' );
 915                 if ( !is_null( $requestid ) ) {
 916                         $result->addValue( null, 'requestid', $requestid );
 917                 }
 918
 919                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
 920                         $servedby = $this->getParameter( 'servedby' );
 921                         if ( $servedby ) {
 922                                 $result->addValue( null, 'servedby', wfHostName() );
 923                         }
 924                 }
 925
 926                 if ( $this->getParameter( 'curtimestamp' ) ) {
 927                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
 928                                 ApiResult::NO_SIZE_CHECK );
 929                 }
 930
 931                 $params = $this->extractRequestParams();
 932
 933                 $this->mAction = $params['action'];
 934
 935                 if ( !is_string( $this->mAction ) ) {
 936                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 937                 }
 938
 939                 return $params;
 940         }
 941
 942         /**
 943          * Set up the module for response
 944          * @return ApiBase The module that will handle this action
 945          * @throws MWException
 946          * @throws UsageException
 947          */
 948         protected function setupModule() {
 949                 // Instantiate the module requested by the user
 950                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
 951                 if ( $module === null ) {
 952                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 953                 }
 954                 $moduleParams = $module->extractRequestParams();
 955
 956                 // Check token, if necessary
 957                 if ( $module->needsToken() === true ) {
 958                         throw new MWException(
 959                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
 960                                 "See documentation for ApiBase::needsToken for details."
 961                         );
 962                 }
 963                 if ( $module->needsToken() ) {
 964                         if ( !$module->mustBePosted() ) {
 965                                 throw new MWException(
 966                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
 967                                 );
 968                         }
 969
 970                         if ( !isset( $moduleParams['token'] ) ) {
 971                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 972                         }
 973
 974                         if ( !$this->getConfig()->get( 'DebugAPI' ) &&
 975                                 array_key_exists(
 976                                         $module->encodeParamName( 'token' ),
 977                                         $this->getRequest()->getQueryValues()
 978                                 )
 979                         ) {
 980                                 $this->dieUsage(
 981                                         "The '{$module->encodeParamName( 'token' )}' parameter was " .
 982                                                 'found in the query string, but must be in the POST body',
 983                                         'mustposttoken'
 984                                 );
 985                         }
 986
 987                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
 988                                 $this->dieUsageMsg( 'sessionfailure' );
 989                         }
 990                 }
 991
 992                 return $module;
 993         }
 994
 995         /**
 996          * Check the max lag if necessary
 997          * @param ApiBase $module Api module being used
 998          * @param array $params Array an array containing the request parameters.
 999          * @return bool True on success, false should exit immediately
1000          */
1001         protected function checkMaxLag( $module, $params ) {
1002                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1003                         $maxLag = $params['maxlag'];
1004                         list( $host, $lag ) = wfGetLB()->getMaxLag();
1005                         if ( $lag > $maxLag ) {
1006                                 $response = $this->getRequest()->response();
1007
1008                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1009                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
1010
1011                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1012                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
1013                                 }
1014
1015                                 $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
1016                         }
1017                 }
1018
1019                 return true;
1020         }
1021
1022         /**
1023          * Check selected RFC 7232 precondition headers
1024          *
1025          * RFC 7232 envisions a particular model where you send your request to "a
1026          * resource", and for write requests that you can read "the resource" by
1027          * changing the method to GET. When the API receives a GET request, it
1028          * works out even though "the resource" from RFC 7232's perspective might
1029          * be many resources from MediaWiki's perspective. But it totally fails for
1030          * a POST, since what HTTP sees as "the resource" is probably just
1031          * "/api.php" with all the interesting bits in the body.
1032          *
1033          * Therefore, we only support RFC 7232 precondition headers for GET (and
1034          * HEAD). That means we don't need to bother with If-Match and
1035          * If-Unmodified-Since since they only apply to modification requests.
1036          *
1037          * And since we don't support Range, If-Range is ignored too.
1038          *
1039          * @since 1.26
1040          * @param ApiBase $module Api module being used
1041          * @return bool True on success, false should exit immediately
1042          */
1043         protected function checkConditionalRequestHeaders( $module ) {
1044                 if ( $this->mInternalMode ) {
1045                         // No headers to check in internal mode
1046                         return true;
1047                 }
1048
1049                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1050                         // Don't check POSTs
1051                         return true;
1052                 }
1053
1054                 $return304 = false;
1055
1056                 $ifNoneMatch = array_diff(
1057                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: array(),
1058                         array( '' )
1059                 );
1060                 if ( $ifNoneMatch ) {
1061                         if ( $ifNoneMatch === array( '*' ) ) {
1062                                 // API responses always "exist"
1063                                 $etag = '*';
1064                         } else {
1065                                 $etag = $module->getConditionalRequestData( 'etag' );
1066                         }
1067                 }
1068                 if ( $ifNoneMatch && $etag !== null ) {
1069                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1070                         $match = array_map( function ( $s ) {
1071                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1072                         }, $ifNoneMatch );
1073                         $return304 = in_array( $test, $match, true );
1074                 } else {
1075                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1076
1077                         // Some old browsers sends sizes after the date, like this:
1078                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1079                         // Ignore that.
1080                         $i = strpos( $value, ';' );
1081                         if ( $i !== false ) {
1082                                 $value = trim( substr( $value, 0, $i ) );
1083                         }
1084
1085                         if ( $value !== '' ) {
1086                                 try {
1087                                         $ts = new MWTimestamp( $value );
1088                                         if (
1089                                                 // RFC 7231 IMF-fixdate
1090                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1091                                                 // RFC 850
1092                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1093                                                 // asctime (with and without space-padded day)
1094                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1095                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1096                                         ) {
1097                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1098                                                 if ( $lastMod !== null ) {
1099                                                         // Mix in some MediaWiki modification times
1100                                                         $modifiedTimes = array(
1101                                                                 'page' => $lastMod,
1102                                                                 'user' => $this->getUser()->getTouched(),
1103                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1104                                                         );
1105                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1106                                                                 // T46570: the core page itself may not change, but resources might
1107                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1108                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1109                                                                 );
1110                                                         }
1111                                                         Hooks::run( 'OutputPageCheckLastModified', array( &$modifiedTimes ) );
1112                                                         $lastMod = max( $modifiedTimes );
1113                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1114                                                 }
1115                                         }
1116                                 } catch ( TimestampException $e ) {
1117                                         // Invalid timestamp, ignore it
1118                                 }
1119                         }
1120                 }
1121
1122                 if ( $return304 ) {
1123                         $this->getRequest()->response()->statusHeader( 304 );
1124
1125                         // Avoid outputting the compressed representation of a zero-length body
1126                         MediaWiki\suppressWarnings();
1127                         ini_set( 'zlib.output_compression', 0 );
1128                         MediaWiki\restoreWarnings();
1129                         wfClearOutputBuffers();
1130
1131                         return false;
1132                 }
1133
1134                 return true;
1135         }
1136
1137         /**
1138          * Check for sufficient permissions to execute
1139          * @param ApiBase $module An Api module
1140          */
1141         protected function checkExecutePermissions( $module ) {
1142                 $user = $this->getUser();
1143                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1144                         !$user->isAllowed( 'read' )
1145                 ) {
1146                         $this->dieUsageMsg( 'readrequired' );
1147                 }
1148
1149                 if ( $module->isWriteMode() ) {
1150                         if ( !$this->mEnableWrite ) {
1151                                 $this->dieUsageMsg( 'writedisabled' );
1152                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1153                                 $this->dieUsageMsg( 'writerequired' );
1154                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1155                                 $this->dieUsage(
1156                                         "Promise-Non-Write-API-Action HTTP header cannot be sent to write API modules",
1157                                         'promised-nonwrite-api'
1158                                 );
1159                         }
1160
1161                         $this->checkReadOnly( $module );
1162                 }
1163
1164                 // Allow extensions to stop execution for arbitrary reasons.
1165                 $message = false;
1166                 if ( !Hooks::run( 'ApiCheckCanExecute', array( $module, $user, &$message ) ) ) {
1167                         $this->dieUsageMsg( $message );
1168                 }
1169         }
1170
1171         /**
1172          * Check if the DB is read-only for this user
1173          * @param ApiBase $module An Api module
1174          */
1175         protected function checkReadOnly( $module ) {
1176                 if ( wfReadOnly() ) {
1177                         $this->dieReadOnly();
1178                 }
1179
1180                 if ( $module->isWriteMode()
1181                         && in_array( 'bot', $this->getUser()->getGroups() )
1182                         && wfGetLB()->getServerCount() > 1
1183                 ) {
1184                         $this->checkBotReadOnly();
1185                 }
1186         }
1187
1188         /**
1189          * Check whether we are readonly for bots
1190          */
1191         private function checkBotReadOnly() {
1192                 // Figure out how many servers have passed the lag threshold
1193                 $numLagged = 0;
1194                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1195                 $laggedServers = array();
1196                 $loadBalancer = wfGetLB();
1197                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1198                         if ( $lag > $lagLimit ) {
1199                                 ++$numLagged;
1200                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1201                         }
1202                 }
1203
1204                 // If a majority of slaves are too lagged then disallow writes
1205                 $slaveCount = wfGetLB()->getServerCount() - 1;
1206                 if ( $numLagged >= ceil( $slaveCount / 2 ) ) {
1207                         $laggedServers = join( ', ', $laggedServers );
1208                         wfDebugLog(
1209                                 'api-readonly',
1210                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1211                         );
1212
1213                         $parsed = $this->parseMsg( array( 'readonlytext' ) );
1214                         $this->dieUsage(
1215                                 $parsed['info'],
1216                                 $parsed['code'],
1217                                 /* http error */
1218                                 0,
1219                                 array( 'readonlyreason' => "Waiting for $numLagged lagged database(s)" )
1220                         );
1221                 }
1222         }
1223
1224         /**
1225          * Check asserts of the user's rights
1226          * @param array $params
1227          */
1228         protected function checkAsserts( $params ) {
1229                 if ( isset( $params['assert'] ) ) {
1230                         $user = $this->getUser();
1231                         switch ( $params['assert'] ) {
1232                                 case 'user':
1233                                         if ( $user->isAnon() ) {
1234                                                 $this->dieUsage( 'Assertion that the user is logged in failed', 'assertuserfailed' );
1235                                         }
1236                                         break;
1237                                 case 'bot':
1238                                         if ( !$user->isAllowed( 'bot' ) ) {
1239                                                 $this->dieUsage( 'Assertion that the user has the bot right failed', 'assertbotfailed' );
1240                                         }
1241                                         break;
1242                         }
1243                 }
1244         }
1245
1246         /**
1247          * Check POST for external response and setup result printer
1248          * @param ApiBase $module An Api module
1249          * @param array $params An array with the request parameters
1250          */
1251         protected function setupExternalResponse( $module, $params ) {
1252                 $request = $this->getRequest();
1253                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1254                         // Module requires POST. GET request might still be allowed
1255                         // if $wgDebugApi is true, otherwise fail.
1256                         $this->dieUsageMsgOrDebug( array( 'mustbeposted', $this->mAction ) );
1257                 }
1258
1259                 // See if custom printer is used
1260                 $this->mPrinter = $module->getCustomPrinter();
1261                 if ( is_null( $this->mPrinter ) ) {
1262                         // Create an appropriate printer
1263                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1264                 }
1265
1266                 if ( $request->getProtocol() === 'http' && (
1267                         $request->getSession()->shouldForceHTTPS() ||
1268                         ( $this->getUser()->isLoggedIn() &&
1269                                 $this->getUser()->requiresHTTPS() )
1270                 ) ) {
1271                         $this->logFeatureUsage( 'https-expected' );
1272                         $this->setWarning( 'HTTP used when HTTPS was expected' );
1273                 }
1274         }
1275
1276         /**
1277          * Execute the actual module, without any error handling
1278          */
1279         protected function executeAction() {
1280                 $params = $this->setupExecuteAction();
1281                 $module = $this->setupModule();
1282                 $this->mModule = $module;
1283
1284                 if ( !$this->mInternalMode ) {
1285                         $this->setRequestExpectations( $module );
1286                 }
1287
1288                 $this->checkExecutePermissions( $module );
1289
1290                 if ( !$this->checkMaxLag( $module, $params ) ) {
1291                         return;
1292                 }
1293
1294                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1295                         return;
1296                 }
1297
1298                 if ( !$this->mInternalMode ) {
1299                         $this->setupExternalResponse( $module, $params );
1300                 }
1301
1302                 $this->checkAsserts( $params );
1303
1304                 // Execute
1305                 $module->execute();
1306                 Hooks::run( 'APIAfterExecute', array( &$module ) );
1307
1308                 $this->reportUnusedParams();
1309
1310                 if ( !$this->mInternalMode ) {
1311                         // append Debug information
1312                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1313
1314                         // Print result data
1315                         $this->printResult( false );
1316                 }
1317         }
1318
1319         /**
1320          * Set database connection, query, and write expectations given this module request
1321          * @param ApiBase $module
1322          */
1323         protected function setRequestExpectations( ApiBase $module ) {
1324                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1325                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1326                 if ( $this->getRequest()->wasPosted() ) {
1327                         if ( $module->isWriteMode() ) {
1328                                 $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1329                         } else {
1330                                 $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1331                         }
1332                 } else {
1333                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1334                 }
1335         }
1336
1337         /**
1338          * Log the preceding request
1339          * @param float $time Time in seconds
1340          */
1341         protected function logRequest( $time ) {
1342                 $request = $this->getRequest();
1343                 $logCtx = array(
1344                         'dt' => date( 'c' ),
1345                         'client_ip' => $request->getIP(),
1346                         'user_agent' => $this->getUserAgent(),
1347                         'wiki' => wfWikiID(),
1348                         'time_backend_ms' => round( $time * 1000 ),
1349                         'params' => array(),
1350                 );
1351
1352                 // Construct space separated message for 'api' log channel
1353                 $msg = "API {$request->getMethod()} " .
1354                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1355                         " {$logCtx['client_ip']} " .
1356                         "T={$logCtx['time_backend_ms']}ms";
1357
1358                 foreach ( $this->getParamsUsed() as $name ) {
1359                         $value = $request->getVal( $name );
1360                         if ( $value === null ) {
1361                                 continue;
1362                         }
1363
1364                         if ( strlen( $value ) > 256 ) {
1365                                 $value = substr( $value, 0, 256 );
1366                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1367                         } else {
1368                                 $encValue = $this->encodeRequestLogValue( $value );
1369                         }
1370
1371                         $logCtx['params'][$name] = $value;
1372                         $msg .= " {$name}={$encValue}";
1373                 }
1374
1375                 wfDebugLog( 'api', $msg, 'private' );
1376                 // ApiRequest channel is for structured data consumers
1377                 wfDebugLog( 'ApiRequest', '', 'private', $logCtx );
1378         }
1379
1380         /**
1381          * Encode a value in a format suitable for a space-separated log line.
1382          * @param string $s
1383          * @return string
1384          */
1385         protected function encodeRequestLogValue( $s ) {
1386                 static $table;
1387                 if ( !$table ) {
1388                         $chars = ';@$!*(),/:';
1389                         $numChars = strlen( $chars );
1390                         for ( $i = 0; $i < $numChars; $i++ ) {
1391                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1392                         }
1393                 }
1394
1395                 return strtr( rawurlencode( $s ), $table );
1396         }
1397
1398         /**
1399          * Get the request parameters used in the course of the preceding execute() request
1400          * @return array
1401          */
1402         protected function getParamsUsed() {
1403                 return array_keys( $this->mParamsUsed );
1404         }
1405
1406         /**
1407          * Get a request value, and register the fact that it was used, for logging.
1408          * @param string $name
1409          * @param mixed $default
1410          * @return mixed
1411          */
1412         public function getVal( $name, $default = null ) {
1413                 $this->mParamsUsed[$name] = true;
1414
1415                 $ret = $this->getRequest()->getVal( $name );
1416                 if ( $ret === null ) {
1417                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1418                                 // See bug 10262 for why we don't just join( '|', ... ) the
1419                                 // array.
1420                                 $this->setWarning(
1421                                         "Parameter '$name' uses unsupported PHP array syntax"
1422                                 );
1423                         }
1424                         $ret = $default;
1425                 }
1426                 return $ret;
1427         }
1428
1429         /**
1430          * Get a boolean request value, and register the fact that the parameter
1431          * was used, for logging.
1432          * @param string $name
1433          * @return bool
1434          */
1435         public function getCheck( $name ) {
1436                 return $this->getVal( $name, null ) !== null;
1437         }
1438
1439         /**
1440          * Get a request upload, and register the fact that it was used, for logging.
1441          *
1442          * @since 1.21
1443          * @param string $name Parameter name
1444          * @return WebRequestUpload
1445          */
1446         public function getUpload( $name ) {
1447                 $this->mParamsUsed[$name] = true;
1448
1449                 return $this->getRequest()->getUpload( $name );
1450         }
1451
1452         /**
1453          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1454          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1455          */
1456         protected function reportUnusedParams() {
1457                 $paramsUsed = $this->getParamsUsed();
1458                 $allParams = $this->getRequest()->getValueNames();
1459
1460                 if ( !$this->mInternalMode ) {
1461                         // Printer has not yet executed; don't warn that its parameters are unused
1462                         $printerParams = array_map(
1463                                 array( $this->mPrinter, 'encodeParamName' ),
1464                                 array_keys( $this->mPrinter->getFinalParams() ?: array() )
1465                         );
1466                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1467                 } else {
1468                         $unusedParams = array_diff( $allParams, $paramsUsed );
1469                 }
1470
1471                 if ( count( $unusedParams ) ) {
1472                         $s = count( $unusedParams ) > 1 ? 's' : '';
1473                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
1474                 }
1475         }
1476
1477         /**
1478          * Print results using the current printer
1479          *
1480          * @param bool $isError
1481          */
1482         protected function printResult( $isError ) {
1483                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1484                         $this->setWarning( 'SECURITY WARNING: $wgDebugAPI is enabled' );
1485                 }
1486
1487                 $printer = $this->mPrinter;
1488                 $printer->initPrinter( false );
1489                 $printer->execute();
1490                 $printer->closePrinter();
1491         }
1492
1493         /**
1494          * @return bool
1495          */
1496         public function isReadMode() {
1497                 return false;
1498         }
1499
1500         /**
1501          * See ApiBase for description.
1502          *
1503          * @return array
1504          */
1505         public function getAllowedParams() {
1506                 return array(
1507                         'action' => array(
1508                                 ApiBase::PARAM_DFLT => 'help',
1509                                 ApiBase::PARAM_TYPE => 'submodule',
1510                         ),
1511                         'format' => array(
1512                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1513                                 ApiBase::PARAM_TYPE => 'submodule',
1514                         ),
1515                         'maxlag' => array(
1516                                 ApiBase::PARAM_TYPE => 'integer'
1517                         ),
1518                         'smaxage' => array(
1519                                 ApiBase::PARAM_TYPE => 'integer',
1520                                 ApiBase::PARAM_DFLT => 0
1521                         ),
1522                         'maxage' => array(
1523                                 ApiBase::PARAM_TYPE => 'integer',
1524                                 ApiBase::PARAM_DFLT => 0
1525                         ),
1526                         'assert' => array(
1527                                 ApiBase::PARAM_TYPE => array( 'user', 'bot' )
1528                         ),
1529                         'requestid' => null,
1530                         'servedby' => false,
1531                         'curtimestamp' => false,
1532                         'origin' => null,
1533                         'uselang' => array(
1534                                 ApiBase::PARAM_DFLT => 'user',
1535                         ),
1536                 );
1537         }
1538
1539         /** @see ApiBase::getExamplesMessages() */
1540         protected function getExamplesMessages() {
1541                 return array(
1542                         'action=help'
1543                                 => 'apihelp-help-example-main',
1544                         'action=help&recursivesubmodules=1'
1545                                 => 'apihelp-help-example-recursive',
1546                 );
1547         }
1548
1549         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1550                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1551                 // reindex the array to get 'permissions' in the right place.
1552                 $oldHelp = $help;
1553                 $help = array();
1554                 foreach ( $oldHelp as $k => $v ) {
1555                         if ( $k === 'submodules' ) {
1556                                 $help['permissions'] = '';
1557                         }
1558                         $help[$k] = $v;
1559                 }
1560                 $help['datatypes'] = '';
1561                 $help['credits'] = '';
1562
1563                 // Fill 'permissions'
1564                 $help['permissions'] .= Html::openElement( 'div',
1565                         array( 'class' => 'apihelp-block apihelp-permissions' ) );
1566                 $m = $this->msg( 'api-help-permissions' );
1567                 if ( !$m->isDisabled() ) {
1568                         $help['permissions'] .= Html::rawElement( 'div', array( 'class' => 'apihelp-block-head' ),
1569                                 $m->numParams( count( self::$mRights ) )->parse()
1570                         );
1571                 }
1572                 $help['permissions'] .= Html::openElement( 'dl' );
1573                 foreach ( self::$mRights as $right => $rightMsg ) {
1574                         $help['permissions'] .= Html::element( 'dt', null, $right );
1575
1576                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1577                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1578
1579                         $groups = array_map( function ( $group ) {
1580                                 return $group == '*' ? 'all' : $group;
1581                         }, User::getGroupsWithPermission( $right ) );
1582
1583                         $help['permissions'] .= Html::rawElement( 'dd', null,
1584                                 $this->msg( 'api-help-permissions-granted-to' )
1585                                         ->numParams( count( $groups ) )
1586                                         ->params( $this->getLanguage()->commaList( $groups ) )
1587                                         ->parse()
1588                         );
1589                 }
1590                 $help['permissions'] .= Html::closeElement( 'dl' );
1591                 $help['permissions'] .= Html::closeElement( 'div' );
1592
1593                 // Fill 'datatypes' and 'credits', if applicable
1594                 if ( empty( $options['nolead'] ) ) {
1595                         $level = $options['headerlevel'];
1596                         $tocnumber = &$options['tocnumber'];
1597
1598                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1599                         $help['datatypes'] .= Html::rawElement( 'h' . min( 6, $level ),
1600                                 array( 'id' => 'main/datatypes', 'class' => 'apihelp-header' ),
1601                                 Html::element( 'span', array( 'id' => Sanitizer::escapeId( 'main/datatypes' ) ) ) .
1602                                 $header
1603                         );
1604                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1605                         if ( !isset( $tocData['main/datatypes'] ) ) {
1606                                 $tocnumber[$level]++;
1607                                 $tocData['main/datatypes'] = array(
1608                                         'toclevel' => count( $tocnumber ),
1609                                         'level' => $level,
1610                                         'anchor' => 'main/datatypes',
1611                                         'line' => $header,
1612                                         'number' => join( '.', $tocnumber ),
1613                                         'index' => false,
1614                                 );
1615                         }
1616
1617                         $header = $this->msg( 'api-credits-header' )->parse();
1618                         $help['credits'] .= Html::rawElement( 'h' . min( 6, $level ),
1619                                 array( 'id' => 'main/credits', 'class' => 'apihelp-header' ),
1620                                 Html::element( 'span', array( 'id' => Sanitizer::escapeId( 'main/credits' ) ) ) .
1621                                 $header
1622                         );
1623                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
1624                         if ( !isset( $tocData['main/credits'] ) ) {
1625                                 $tocnumber[$level]++;
1626                                 $tocData['main/credits'] = array(
1627                                         'toclevel' => count( $tocnumber ),
1628                                         'level' => $level,
1629                                         'anchor' => 'main/credits',
1630                                         'line' => $header,
1631                                         'number' => join( '.', $tocnumber ),
1632                                         'index' => false,
1633                                 );
1634                         }
1635                 }
1636         }
1637
1638         private $mCanApiHighLimits = null;
1639
1640         /**
1641          * Check whether the current user is allowed to use high limits
1642          * @return bool
1643          */
1644         public function canApiHighLimits() {
1645                 if ( !isset( $this->mCanApiHighLimits ) ) {
1646                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1647                 }
1648
1649                 return $this->mCanApiHighLimits;
1650         }
1651
1652         /**
1653          * Overrides to return this instance's module manager.
1654          * @return ApiModuleManager
1655          */
1656         public function getModuleManager() {
1657                 return $this->mModuleMgr;
1658         }
1659
1660         /**
1661          * Fetches the user agent used for this request
1662          *
1663          * The value will be the combination of the 'Api-User-Agent' header (if
1664          * any) and the standard User-Agent header (if any).
1665          *
1666          * @return string
1667          */
1668         public function getUserAgent() {
1669                 return trim(
1670                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
1671                         $this->getRequest()->getHeader( 'User-agent' )
1672                 );
1673         }
1674
1675         /************************************************************************//**
1676          * @name   Deprecated
1677          * @{
1678          */
1679
1680         /**
1681          * Sets whether the pretty-printer should format *bold* and $italics$
1682          *
1683          * @deprecated since 1.25
1684          * @param bool $help
1685          */
1686         public function setHelp( $help = true ) {
1687                 wfDeprecated( __METHOD__, '1.25' );
1688                 $this->mPrinter->setHelp( $help );
1689         }
1690
1691         /**
1692          * Override the parent to generate help messages for all available modules.
1693          *
1694          * @deprecated since 1.25
1695          * @return string
1696          */
1697         public function makeHelpMsg() {
1698                 wfDeprecated( __METHOD__, '1.25' );
1699
1700                 $this->setHelp();
1701                 $cacheHelpTimeout = $this->getConfig()->get( 'APICacheHelpTimeout' );
1702
1703                 return ObjectCache::getMainWANInstance()->getWithSetCallback(
1704                         wfMemcKey(
1705                                 'apihelp',
1706                                 $this->getModuleName(),
1707                                 str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) )
1708                         ),
1709                         $cacheHelpTimeout > 0 ? $cacheHelpTimeout : WANObjectCache::TTL_UNCACHEABLE,
1710                         array( $this, 'reallyMakeHelpMsg' )
1711                 );
1712         }
1713
1714         /**
1715          * @deprecated since 1.25
1716          * @return mixed|string
1717          */
1718         public function reallyMakeHelpMsg() {
1719                 wfDeprecated( __METHOD__, '1.25' );
1720                 $this->setHelp();
1721
1722                 // Use parent to make default message for the main module
1723                 $msg = parent::makeHelpMsg();
1724
1725                 $astriks = str_repeat( '*** ', 14 );
1726                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1727
1728                 foreach ( $this->mModuleMgr->getNames( 'action' ) as $name ) {
1729                         $module = $this->mModuleMgr->getModule( $name );
1730                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1731
1732                         $msg2 = $module->makeHelpMsg();
1733                         if ( $msg2 !== false ) {
1734                                 $msg .= $msg2;
1735                         }
1736                         $msg .= "\n";
1737                 }
1738
1739                 $msg .= "\n$astriks Permissions $astriks\n\n";
1740                 foreach ( self::$mRights as $right => $rightMsg ) {
1741                         $rightsMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )
1742                                 ->useDatabase( false )
1743                                 ->inLanguage( 'en' )
1744                                 ->text();
1745                         $groups = User::getGroupsWithPermission( $right );
1746                         $msg .= "* " . $right . " *\n  $rightsMsg" .
1747                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1748                 }
1749
1750                 $msg .= "\n$astriks Formats  $astriks\n\n";
1751                 foreach ( $this->mModuleMgr->getNames( 'format' ) as $name ) {
1752                         $module = $this->mModuleMgr->getModule( $name );
1753                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1754                         $msg2 = $module->makeHelpMsg();
1755                         if ( $msg2 !== false ) {
1756                                 $msg .= $msg2;
1757                         }
1758                         $msg .= "\n";
1759                 }
1760
1761                 $credits = $this->msg( 'api-credits' )->useDatabase( 'false' )->inLanguage( 'en' )->text();
1762                 $credits = str_replace( "\n", "\n   ", $credits );
1763                 $msg .= "\n*** Credits: ***\n   $credits\n";
1764
1765                 return $msg;
1766         }
1767
1768         /**
1769          * @deprecated since 1.25
1770          * @param ApiBase $module
1771          * @param string $paramName What type of request is this? e.g. action,
1772          *    query, list, prop, meta, format
1773          * @return string
1774          */
1775         public static function makeHelpMsgHeader( $module, $paramName ) {
1776                 wfDeprecated( __METHOD__, '1.25' );
1777                 $modulePrefix = $module->getModulePrefix();
1778                 if ( strval( $modulePrefix ) !== '' ) {
1779                         $modulePrefix = "($modulePrefix) ";
1780                 }
1781
1782                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1783         }
1784
1785         /**
1786          * Check whether the user wants us to show version information in the API help
1787          * @return bool
1788          * @deprecated since 1.21, always returns false
1789          */
1790         public function getShowVersions() {
1791                 wfDeprecated( __METHOD__, '1.21' );
1792
1793                 return false;
1794         }
1795
1796         /**
1797          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1798          * classes who wish to add their own modules to their lexicon or override the
1799          * behavior of inherent ones.
1800          *
1801          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1802          * @param string $name The identifier for this module.
1803          * @param ApiBase $class The class where this module is implemented.
1804          */
1805         protected function addModule( $name, $class ) {
1806                 $this->getModuleManager()->addModule( $name, 'action', $class );
1807         }
1808
1809         /**
1810          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1811          * classes who wish to add to or modify current formatters.
1812          *
1813          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1814          * @param string $name The identifier for this format.
1815          * @param ApiFormatBase $class The class implementing this format.
1816          */
1817         protected function addFormat( $name, $class ) {
1818                 $this->getModuleManager()->addModule( $name, 'format', $class );
1819         }
1820
1821         /**
1822          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1823          *
1824          * @since 1.18
1825          * @deprecated since 1.21, Use getModuleManager()'s methods instead.
1826          * @return array
1827          */
1828         public function getFormats() {
1829                 return $this->getModuleManager()->getNamesWithClasses( 'format' );
1830         }
1831
1832         /**@}*/
1833
1834 }
1835
1836 /**
1837  * This exception will be thrown when dieUsage is called to stop module execution.
1838  *
1839  * @ingroup API
1840  */
1841 class UsageException extends MWException {
1842
1843         private $mCodestr;
1844
1845         /**
1846          * @var null|array
1847          */
1848         private $mExtraData;
1849
1850         /**
1851          * @param string $message
1852          * @param string $codestr
1853          * @param int $code
1854          * @param array|null $extradata
1855          */
1856         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1857                 parent::__construct( $message, $code );
1858                 $this->mCodestr = $codestr;
1859                 $this->mExtraData = $extradata;
1860         }
1861
1862         /**
1863          * @return string
1864          */
1865         public function getCodeString() {
1866                 return $this->mCodestr;
1867         }
1868
1869         /**
1870          * @return array
1871          */
1872         public function getMessageArray() {
1873                 $result = array(
1874                         'code' => $this->mCodestr,
1875                         'info' => $this->getMessage()
1876                 );
1877                 if ( is_array( $this->mExtraData ) ) {
1878                         $result = array_merge( $result, $this->mExtraData );
1879                 }
1880
1881                 return $result;
1882         }
1883
1884         /**
1885          * @return string
1886          */
1887         public function __toString() {
1888                 return "{$this->getCodeString()}: {$this->getMessage()}";
1889         }
1890 }
1891
1892 /**
1893  * For really cool vim folding this needs to be at the end:
1894  * vim: foldmarker=@{,@} foldmethod=marker
1895  */